The Essential Guide to Fitness, 4th Edition by Marchese Taylor (2019) [4 ed.] 0170413705

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The Essential Guide to Fitness, 4th Edition by Marchese Taylor (2019) [4 ed.]
 0170413705

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  • The Essential Guide to Fitness, for fitness instructor

Table of contents :
Title page
Imprint page
Brief contents
Contents
Guide to the text
Guide to the online resources
Preface
About the authors
Acknowledgements
Part 1: Introduction to the human body and healthy eating
Chapter 1: Anatomy and physiology
Introduction
1.1 Anatomy and physiology principles and terminology
1.2 The structural levels of organisation in the human body
1.3 Musculoskeletal system
1.4 The cardiorespiratory system
1.5 The nervous system
1.6 The digestive system
1.7 Energy systems
Chapter 2: Nutrition
Introduction
2.1 Healthy eating
2.2 The Australian Dietary Guidelines
2.3 What is the scope of practice for an Australian fitness instructor?
2.4 A balanced diet
2.5 Balanced nutrition
2.6 Supporting positive attitudes towards healthy eating and body composition
2.7 Referral requirements
Part 2: Fitness orientation and
health screening
Chapter 3: Fitness orientation and health screening
Introduction
3.1 Client orientation and induction
3.2 Identifying general client fitness requirements
3.3 Administering and processing pre-exercise health screening questionnaires
3.4 The Adult Pre-exercise Screening System (APSS)
3.5 Pre-participation health screening
3.6 Medical examination prior to initiating physical activity
3.7 Making an appointment for a fitness appraisal
3.8 Record-keeping
Part 3: Fitness programming, instruction and equipment
Chapter 4: Fitness appraisals
Introduction
4.1 Step 1: Determining client goals
4.2 Step 2: Conducting fitness appraisals
4.3 Step 3: Adherence to behavioural change strategies
4.4 Re-evaluation and follow-up
Chapter 5: Fitness programs
Introduction
5.1 Identifying client fitness requirements
5.2 Goal setting
5.3 Program design
5.4 Developing fitness programs
5.5 Motivating clients to maximise exercise adherence
5.6 Monitoring and evaluating a program
5.7 Work health and safety (WHS) considerations
5.8 Delayed onset muscle soreness (DOMS)
Chapter 6: Gym programs
Introduction
6.1 Conducting a needs analysis
6.2 Resistance training concepts
6.3 Planning and instructing customised gym resistance programs
6.4 Circuit training
Chapter 7: Fitness equipment
Introduction
7.1 General maintenance or repair recommendations
7.2 General maintenance guidelines for resistance equipment
7.3 Cardiovascular equipment
7.4 Heart-rate monitors
Chapter 8: Group exercise sessions
Introduction
8.1 Planning and developing the group exercise session
8.2 Plan and instruct a group exercise session
8.3 Freestyle sessions
8.4 Developing a library of moves and other tips
8.5 Methods of teaching
8.6 Evaluating group sessions
Chapter 9: Water-based fitness
Introduction
9.1 Determining the needs of clients
9.2 Legislation, regulations and work health and safety (WHS)
9.3 Best-practice principles of aquatic activities
9.4 Water familiarisation, buoyancy and mobility skills
9.5 Developing the water session plan
9.6 Planning circuits, drills, activities and games
9.7 Conducting water-based fitness sessions
9.8 Analysis and feedback
9.9 Basic water rescues and safety
Chapter 10: Endurance training programs
Introduction
10.1 Developing an endurance training program
10.2 Types of endurance training programs
10.3 Adaptations to endurance training
10.4 Overtraining
10.5 Fatigue
10.6 Delivering the endurance training program
Part 4: Risk analysis and work health and safety
Chapter 11: Risk analysis and work health and safety
Introduction
11.1 An update on work health and safety (WHS) in Australia
11.2 Responsibility for risk management
11.3 Identification of risk within an activity
11.4 Risk analysis and assessment
11.5 Minimising risk
Part 5: Specific markets and populations
Chapter 12: Fitness for specific populations
Introduction
12.1 Identifying the requirements of clients from specific population groups
12.2 Medical and allied health professionals
12.3 Medical conditions and exercise
12.4 Clients with a disability
12.5 Culturally and linguistically diverse groups
Chapter 13: Older populations
Introduction
13.1 Typical anatomical and physiological considerations for older clients
13.2 Benefits of exercise for older people
13.3 Recommended frequency, intensity, duration and type of exercise for
older adults
13.4 Precautions to exercise testing for older adults
13.5 Common barriers to exercise participation by older clients
13.6 Exercise considerations during the ageing process
Chapter 14: Children andadolescents
Introduction
14.1 Anatomy and physiology related to children
14.2 Stages of growth and development in children
14.3 Selection of appropriate exercise for children
14.4 Pre-screening and risk stratification procedures and referral requirements
14.5 Planning movement sessions for children using principles of exercise
program design
14.6 Instructing and evaluating movement sessions for children
Chapter 15: Community fitness programs
Introduction
15.1 Approved community fitness programs
15.2 Participation in an approved community fitness program
15.3 Legislation and regulatory requirements
15.4 Culturally and linguistically diverse groups
Chapter 16: Facilitating groups
Introduction
16.1 Planning for the establishment of a group – what does facilitation involve?
16.2 Developing group commitment and cooperation
16.3 Facilitating group processes
Part 6: Working in a fitness environment
Chapter 17: Quality service in the fitness industry
Introduction
17.1 The national fitness industry quality framework
17.2 Addressing client requests
17.3 Implementing quality customer service within a fitness facility
17.4 Communicating with clients
17.5 Responding to client complaints
Glossary
References and bibliography
Index

Citation preview

Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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THE ESSENTIAL GUIDE TO

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MARCHESE TAYLOR FAGAN Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

iii

BRIEF CONTENTS PART 1: Introduction to the human body and healthy eating 1 Anatomy and physiology 2 Nutrition

PART 2: Fitness orientation and health screening 3 Fitness orientation and health screening

1

PART 4: Risk analysis and work health and safety

347

2 66

11 Risk analysis and work health and safety

348

99

PART 5: Specific markets and populations 359

100

PART 3: Fitness programming, instruction and equipment 126 4 Fitness appraisals 127 5 Fitness programs 172 6 Gym programs 222 7 Fitness equipment 260 8 Group exercise sessions 277 9 Water-based fitness 295 10 Endurance training programs 327

12 Fitness for specific populations 360 13 Older populations 391 14 Children and adolescents 408 15 Community fitness programs 425 16 Facilitating groups 435

PART 6: Working in a fitness environment 447 17 Quality service in the fitness industry

Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

448

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CONTENTS GUIDE TO THE TEXT................................................................................................................................................. VIII GUIDE TO THE ONLINE RESOURCES................................................................................................................................ X PREFACE................................................................................................................................................................ XII ABOUT THE AUTHORS.............................................................................................................................................. XIII ACKNOWLEDGEMENTS............................................................................................................................................. XIV

PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING....................................... 1 1 ANATOMY AND PHYSIOLOGY....................................................................................................2 Introduction............................................................................................................................................2 1.1  Anatomy and physiology principles and terminology.............................................................2 1.2  The structural levels of organisation in the human body..................................................... 11 1.3  Musculoskeletal system.............................................................................................................. 20 1.4  The cardiorespiratory system.................................................................................................... 45 1.5  The nervous system.................................................................................................................... 52 1.6  The digestive system....................................................................................................................57 1.7  Energy systems............................................................................................................................. 59

2 NUTRITION......................................................................................................................... 66 Introduction......................................................................................................................................... 66 2.1  Healthy eating............................................................................................................................... 66 2.2 The Australian Dietary Guidelines............................................................................................ 69 2.3  What is the scope of practice for an Australian fitness instructor?................................... 79 2.4  A balanced diet............................................................................................................................ 79 2.5  Balanced nutrition....................................................................................................................... 83 2.6  Supporting positive attitudes towards healthy eating and body composition............... 93 2.7  Referral requirements................................................................................................................. 96

PART 2: FITNESS ORIENTATION AND HEALTH SCREENING.................................................... 99 3 FITNESS ORIENTATION AND HEALTH SCREENING......................................................................100 Introduction....................................................................................................................................... 100 3.1  Client orientation and induction.............................................................................................101 3.2  Identifying general client fitness requirements.................................................................. 102 3.3  Administering and processing pre-exercise health screening questionnaires............. 103 3.4  The Adult Pre-exercise Screening System (APSS)............................................................... 106 3.5  Pre-participation health screening.........................................................................................115 3.6  Medical examination prior to initiating physical activity....................................................116 3.7  Making an appointment for a fitness appraisal.....................................................................121 3.8 Record-keeping......................................................................................................................... 122

PART 3: FITNESS PROGRAMMING, INSTRUCTION AND EQUIPMENT........................................126 4 FITNESS APPRAISALS......................................................................................................... 127 Introduction........................................................................................................................................127 4.1  Step 1: Determining client goals............................................................................................. 128 4.2  Step 2: Conducting fitness appraisals................................................................................... 130 4.3  Step 3: Adherence to behavioural change strategies......................................................... 166 4.4  Re-evaluation and follow-up.................................................................................................. 169

Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

CONTENTS

5 FITNESS PROGRAMS........................................................................................................... 172 Introduction........................................................................................................................................172 5.1  Identifying client fitness requirements...................................................................................172 5.2  Goal setting..................................................................................................................................174 5.3  Program design...........................................................................................................................174 5.4  Developing fitness programs.................................................................................................. 182 5.5  Motivating clients to maximise exercise adherence........................................................... 212 5.6  Monitoring and evaluating a program................................................................................... 214 5.7  Work health and safety (WHS) considerations..................................................................... 215 5.8  Delayed onset muscle soreness (DOMS).............................................................................. 218

6 GYM PROGRAMS............................................................................................................... 222 Introduction....................................................................................................................................... 222 6.1  Conducting a needs analysis................................................................................................... 222 6.2  Resistance training concepts.................................................................................................. 223 6.3  Planning and instructing customised gym resistance programs.................................... 223 6.4  Circuit training........................................................................................................................... 239

7 FITNESS EQUIPMENT.......................................................................................................... 260 Introduction.......................................................................................................................................260 7.1  General maintenance or repair recommendations............................................................. 261 7.2  General maintenance guidelines for resistance equipment............................................. 267 7.3  Cardiovascular equipment....................................................................................................... 267 7.4  Heart-rate monitors....................................................................................................................271

8 GROUP EXERCISE SESSIONS................................................................................................ 277 Introduction....................................................................................................................................... 277 8.1  Planning and developing the group exercise session........................................................ 277 8.2  Plan and instruct a group exercise session..........................................................................280 8.3  Freestyle sessions......................................................................................................................288 8.4  Developing a library of moves and other tips......................................................................290 8.5  Methods of teaching................................................................................................................. 291 8.6  Evaluating group sessions........................................................................................................ 292

9 WATER-BASED FITNESS...................................................................................................... 295 Introduction....................................................................................................................................... 295 9.1  Determining the needs of clients...........................................................................................296 9.2  Legislation, regulations and work health and safety (WHS).............................................299 9.3  Best-practice principles of aquatic activities....................................................................... 301 9.4  Water familiarisation, buoyancy and mobility skills........................................................... 302 9.5  Developing the water session plan........................................................................................ 305 9.6  Planning circuits, drills, activities and games...................................................................... 312 9.7  Conducting water-based fitness sessions............................................................................ 314 9.8  Analysis and feedback.............................................................................................................. 318 9.9  Basic water rescues and safety............................................................................................... 319

10 ENDURANCE TRAINING PROGRAMS....................................................................................... 327 Introduction....................................................................................................................................... 327 10.1  Developing an endurance training program...................................................................... 327 10.2  Types of endurance training programs............................................................................... 328 10.3  Adaptations to endurance training ..................................................................................... 330 10.4 Overtraining.............................................................................................................................. 335 10.5 Fatigue........................................................................................................................................ 336 10.6  Delivering the endurance training program...................................................................... 337

Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

v

vi

CONTENTS

PART 4: RISK ANALYSIS AND WORK HEALTH AND SAFETY................................................. 347 11 RISK ANALYSIS AND WORK HEALTH AND SAFETY.................................................................... 348 Introduction.......................................................................................................................................348 11.1  An update on work health and safety (WHS) in Australia.................................................348 11.2  Responsibility for risk management.................................................................................... 350 11.3  Identification of risk within an activity................................................................................ 352 11.4  Risk analysis and assessment................................................................................................ 352 11.5  Minimising risk ......................................................................................................................... 355

PART 5: SPECIFIC MARKETS AND POPULATIONS.............................................................. 359 12 FITNESS FOR SPECIFIC POPULATIONS................................................................................... 360 Introduction.......................................................................................................................................360 12.1  Identifying the requirements of clients from specific population groups...................360 12.2  Medical and allied health professionals.............................................................................. 361 12.3  Medical conditions and exercise.......................................................................................... 361 12.4  Clients with a disability...........................................................................................................384 12.5  Culturally and linguistically diverse groups........................................................................ 387

13 OLDER POPULATIONS..........................................................................................................391 Introduction....................................................................................................................................... 391 13.1  Typical anatomical and physiological considerations for older clients........................ 391 13.2  Benefits of exercise for older people.................................................................................. 393 13.3 Recommended frequency, intensity, duration and type of exercise for older adults............................................................................................................................... 394 13.4  Precautions to exercise testing for older adults................................................................ 396 13.5  Common barriers to exercise participation by older clients.......................................... 401 13.6  Exercise considerations during the ageing process.........................................................402

14 CHILDREN AND ADOLESCENTS............................................................................................. 408 Introduction.......................................................................................................................................408 14.1  Anatomy and physiology related to children.....................................................................408 14.2  Stages of growth and development in children................................................................ 413 14.3  Selection of appropriate exercise for children.................................................................. 416 14.4  Pre-screening and risk stratification procedures and referral requirements.............. 418 14.5 Planning movement sessions for children using principles of exercise program design..........................................................................................................................419 14.6  Instructing and evaluating movement sessions for children.......................................... 421

15 COMMUNITY FITNESS PROGRAMS......................................................................................... 425 Introduction....................................................................................................................................... 425 15.1  Approved community fitness programs.............................................................................. 425 15.2  Participation in an approved community fitness program............................................. 428 15.3  Legislation and regulatory requirements...........................................................................429 15.4  Culturally and linguistically diverse groups........................................................................ 431

Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

CONTENTS

16 FACILITATING GROUPS....................................................................................................... 435 Introduction....................................................................................................................................... 435 16.1  Planning for the establishment of a group – what does facilitation involve?............. 435 16.2  Developing group commitment and cooperation........................................................... 439 16.3  Facilitating group processes..................................................................................................443

PART 6: WORKING IN A FITNESS ENVIRONMENT.............................................................. 447 17 QUALITY SERVICE IN THE FITNESS INDUSTRY ........................................................................ 448 Introduction ......................................................................................................................................448 17.1  The national fitness industry quality framework ..............................................................448 17.2  Addressing client requests.....................................................................................................449 17.3  Implementing quality customer service within a fitness facility.................................... 452 17.4  Communicating with clients.................................................................................................. 455 17.5  Responding to client complaints..........................................................................................460 GLOSSARY ........................................................................................................................................................... 464 REFERENCES AND BIBLIOGRAPHY............................................................................................................................. 475 INDEX.................................................................................................................................................................. 483

Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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Guide to the text 277

As you read this text you will find a number of features in every chapter to enhance your study of fitness training, helping you to understand how the theory is applied in the real world.

8

Group exercise sessions

LO

INTRODUCTION

LO

CHAPTER CHAPTER

OBJECTIVES chapter involves application of the following CHAPTERThis FEATURES topics: 8.1 Planning and developing group exercise Identify the keysessions concepts that the chapter will cover with the learning objectives at the start of 8.2 Look Planningout and instructing group exercise each chapter. for learning objective icons throughout the text to find where each sessions 277 objective is explored. 8.3 Developing and delivering freestyle sessions 8.4 Developing a library of moves and other tips, such as changing the intensity of a session 8.5 Understanding methods of teaching 8.6 Evaluating group exercise sessions. OBJECTIVES This chapter involves application of the following topics: 8.1 Planning and developing group exercise sessions Group exercise sessions are a fun way to increase fitness. In the past, they consisted predominantly 8.2 Planningcharacterised and instructing exercise of classes by group a group format, the use of music and an instructor who designed and led the sessions class. Group exercise to music became particularly popular in the 1980s, and has continued to 14 PART 1: INTRODUCTION TO HUMAN HEALTHY EATING be a major source of income for fitnessTHE facilities and BODY fitnessAND instructors. The popularity of class types 8.3 Developing and delivering freestyle sessions has varied over the years, beginning with a more freestyle approach and progressing to today’s wide 8.4 Developing a library of moves and other tips, variety of exercise sessions to suit different needs and levels of ability. mitochondria such asnumbers changingofthemuscle intensity of a session are largely responsible for the increased resistance to fatigue and the health benefits associated withenjoyment aerobic exercise, as running andthe cycling. factors have an impact on clients’ level insuch classes, including music, the TIP 8.5Many Understanding methods of teaching It is important to have a basic understanding of the cell structure and energy provision because format and the instructor’s personality. 8.6session Evaluating group exercise sessions. they relate to training modalities and positive adaptations to the body under exercise conditions.

8

Group exercise sessions

The energy requirements of training are also important to the fitness instructor when programming

exercise for clients. 8.1 PLANNING AND DEVELOPING THE GROUP EXERCISE INTRODUCTION SESSION Haemoglobin

Haemoglobin The protein in blood that carries oxygen from blood to the body tissues

Group exercise a fun to exercise increase fitness. Inbut themost past, involve they consisted predominantly There manysessions differentare of way group the Metabolism The sum are Haemoglobin intypes blood carries oxygensessions, from respiratory organs (thefollowing lungs) totypes the of rest of the of the physical ofand classesbody characterised byHere, a group format, the use of to music and nutrients an instructor who designed led energy phases: (tissues). oxygen is released enable to be burned to and provide chemical processes the class. for Group exercise to music This became particularly popular in the 1980s, and has to and is a Planning: before the functions. session necessary to • sustain everyday process of ‘burning nutrients’ is known as continued metabolism life and provide majorcontinuous source ofbeginning income for facilities and fitness instructors. The popularity of class types •be aWarm-up: at the offitness the session process. energy to the body varied over the years,the beginning •hasConditioning: during session with a more freestyle approach and progressing to today’s wide

Myoglobin

Myoglobin A • variety of exercise sessions to suit different needs and ability. Recovery: during the session (e.g. rest between sets,levels at theofend of the session or between sessions; protein found in heart and skeletalin some instances, this may also be called a cool-down) Many factors have an impact on clients’ enjoyment level in classes, the music, the muscle tissues that • Adaptation: after each session,found as theinbody and gets usedtissues. toincluding the increasing demands Myoglobin is a protein heartrecovers and skeletal muscle It is responsible for binding is responsible for session format and the instructor’s personality. Review: after the fromyou theexercise, instructor’s clients’ of view. binding with •oxygen oxygen andsession, iron. When theand muscles willpoint use up the available oxygen. Myoblobin is and iron

Check your understanding and engage actively and personally with the chapter concepts by TIP with completing the Workout activities as you progress through the chapter. only found in blood after muscle injuries.

1 Explain the differences between three different types and their functions. Describe an 8.1 PLANNING AND DEVELOPING THEcellGROUP EXERCISE example of how these cells may change over time with an exercise program. SESSION 2 Explain the function of the following parts of a cell:

WORKOUT 1.2

a Cell membrane There are many different types of group exercise sessions, but most involve the following types of b Mitochondria phases: c Nucleus. • Planning: before the session 3 Muscle cells contain lots of mitochondria and myoglobin. Research and explain the effects of • Warm-up: at the beginning of the session endurance training on these components. • Conditioning: during the session 4 Research the effect and causes of low haemoglobin in the body and what you would do if your • Recovery: during the session (e.g. rest between sets, at the end of the session or between sessions; client showed signs and symptoms of low haemoglobin. in some instances, this may also be called a cool-down) • Adaptation: after each session, as the body recovers and gets used to the increasing demands BK-CLA-MARCHESE4E-180280-Chp08.indd 277 after the the session, fromincluded the instructor’s and clients’ point view. Be prepared• byReview: reviewing Tips throughout on ofimportant things to consider

Types of tissues

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and

CHAPTER 1 muscle There are four types of tissues in the body: epithelia, connective tissue, nervous tissue and remember as a fitness trainer.

43

Anatomy and physiology tissue. These are explained in detail in Table 1.3. Connective tissue is found in various places within the human body. Examples of connective tissue Connective tissue The supporting that are of particular interest fitness instructors ligaments, tendons,and fascia and cartilage. ST (type I) muscle fibres have a redto pigmentation due toinclude abundant mitochondrial framework of the body that helps myoglobin to levels. Compared to FT (type II) muscle fibres they are fatigue-resistant and more support, bind or Tablefor1.3 Typestypes of tissues appropriate aerobic of exercise. ST muscle fibres, in comparison to FT muscle fibres: separate other body tissues • transmit an electric signal more slowly

• • • • •

TIP

Tissue type Function Description have lots of mitochondria (for breakdown of ATP with the use of oxygen) Epithelium Protects the body from There are two main types of epithelia. The first type have low myosin ATPase levels covers or lines internal and external surfaces (e.g. the have lots of myoglobin moisture loss, bacteria, radiation and physical skin and the internal surface lining of the digestive are highly fatigue-resistant trauma tract). The second type, glandular epithelium, secretes have a higher blood flow.

BK-CLA-MARCHESE4E-180280-Chp08.indd 277

Muscle fatigue

hormones (chemicals that send signals around the body to create changes or maintain homeostasis) or other products, such as milk, saliva, sweat and acid.

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Fatigue is the reduction in muscle a given time period. Fatigue in holds skeletal can Connective Provides tension structureinand Loose connective tissue bodymuscle structures together Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, innervous whole or in part. occur alongtissue one or more ofsupport the parts involved in a muscle in the system, inWCN 02-200-202 to the body (e.g.contraction, it holds the outer layer of the skin to the tissue beneath).the Fibrous tissue holdsduring body parts the neuromuscular junction or in the muscle fibre itself. Usually, mainconnective reason for fatigue but it isfibres, strong no andmatter rigid compared to loose prolonged exercise is the lack of fuel (glycogen) within thetogether, active muscle how much connective tissue. Fibrous connective tissue includes oxygen is available. This is known as nutrient fatigue. There may also be a lack of oxygen to provide

ximum rapport with a client, be prepared and do the following: movement and heat TIP the heart), smooth (that lines the walls of blood vessels ent in a friendly and courteous way. and organs such as the digestive system) and skeletal urself and your position to your client. (that attaches to bones and causes movements of the body). nt in a comfortable position. act. GUIDE TO THE TEXT f in a position with clear access to the client and required materials. Ligaments en information on the organisation’s facilities, products and services. Ligaments are very important to the structure of a joint (where two bones meet), functioning to Ligaments ppropriate pace. Connective tissue client and work with them to achieve goals. connect bone to bone and provide stability to the joint. For example, the medial collateral ligament that joins bone to of the knee connects the femur (the long bone in the thigh) to the tibia (the shin bone) and helps to bone provide the knee stability. Ligaments are prone to injury (partial or complete tears) if a joint is forced too ved in starting an exercise program with a client include following: far inthe a particular direction. Ligaments can adapt to increases or decreases in mechanical loading by on. Collect and assess information, including about client’s current physicaladjusting their size, material properties or both, but they have a limited blood supply and can take a s, and identify and clarify the client’s needs and expectations. Important key terms are marked in bold in the text and defined in the margin when they are used long time toa heal. Theappointment composition of ligaments allows them to contribute to restriction of movement; reening procedures. Use a questionnaire to identify whether medical however, they are also slightly and elastic, allowing you to gradually lengthen them in a flexibility program. inofthe the first time. quired, and to determine the level risk text in the for client’s participation in exercise

ix

CHAPTER FEATURES

y. al. This involves fitness assessments of clients, where necessary. Tendons an exercise program. Tendons attach skeletal muscle to bone. For example, the Achilles tendon attaches the gastrocnemius g sessions. (calf muscle) to the calcaneus (heel bone). Tendons have to withstand transversal and rotational of the exercise program and reassessment of forces fitnessas appraisals – for example, well as contusions (bruises) and other pressures. Sometimes they just do not cope and are f muscle strength after six weeks of training. susceptible to overload injuries where they partially or completely tear, at times even taking some ill focus on the first two parts of this processbone – client orientation and health with them (commonly known as an avulsion fracture). Like ligaments, tendons have a poor

blood supply, and recovery from injury can therefore be slow. Exercise, growth and injury can place severe stress on the spot on the bone where the tendon connects (either the origin or insertion point). The bone responds with overgrowth, and this is where you find some prominent bony landmarks – for example, the greater tubercle. More research is needed to confirm the program. exact effects nd induction is the first step in introducing a client to a physical-activity It of training on tendons, but it appears that the effects of rest and immobilisation tend to an beexercise less severe on tendons than on muscle. spective clients to be anxious and possibly intimidated about beginning

T ORIENTATION AND INDUCTION

Tendons Connective tissue that joins muscle to bone Origin The more fixed end or attachment of a muscle to a bone (compared to insertion) Insertion The end of the muscle that is attached to the bone that moves

hould attempt to make any new client comfortable in their new surroundings. ent that the information you gather will be treated in a confidential manner. You Fascia d consent to share the information with other parties. the type information has tissue. There are two types of fascia: superficial fascia, which lies Fascia isOnce a special of connective Fascia The type of forms the beginning of your client’s file and should be the stored formovement of the skin, and deep fascia, which covers and separates connective tissue beneath skin appropriately and permits free forming layers d comparison. It is becoming popular for fitness instructors to complete electronic layers of muscles. around different ms. This reduces the use of paper and maintains client privacy. tissues of the body Fascia provides the body with a network to connect many structures of the body. It allows forces g and recording information from a client regarding health or lifestyle, can to be transmitted throughyou body segments to allow for smooth movement. ORAL Feel confident that you are Expand your understanding of how rocess whereby you ask the client a question and then record the answer on the COMMUNICATION, PLANNING & ee Table 3.1 for the content that is to be included inprinciples these forms. Speak clearly and developing the foundational sustainability can be Cartilage ORGANISING op to confirm understanding or to answer questions from the client. Avoid making SKILLS, skills and abilities required to applied in the fitness industry a type of connective Cartilage A type of shing the client’s sentences; instead, try to adoptCartilage a relaxed is interviewing technique. tissue that manages tension and compression. It varies in form connective tissue depending on location and function (see Figure 1.9). It is tough but flexible, and lacks nerve fibres. number of advantages, since it:where you see successfully complete your content marked receives its nutrients from a diffusion process whereby the surrounding blood vessels ‘pass process and follows a screening tool endorsed byCartilage Fitness Australia qualification by reviewing the content marked with a with a sustainability icon. over’not thecompletely required nutrients. aborate on or clarify any questions your client does understand

ICONS

lient from simply indicating ‘Yes’ or ‘No’ without actually reading the question nt to completely formulate their views ecord additional information that your client considers to be important e to think about the client’s responses.

Foundation skills icon – Literacy, Numeracy, Communication, Technology, Planning, Learning skills

ORAL COMMUNI­ CATION AND WRITING SKILLS

END-OF-CHAPTER FEATURES BK-CLA-MARCHESE4E-180280-Chp01.indd 15

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At the end of each chapter you will find several tools to help you to review, practise and extend your knowledge of the key learning outcomes.

64

• Review your understanding of the key chapter topics with Chapter summary. PART 1: INTRODUCTION TO THE HUMAN BODYthe AND HEALTHY EATING

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Chapter summary 64

The study of anatomy and physiology is very important when learning how to instruct fitness clients. Without knowing how the body works, you will be unable to plan and instruct effective fitness programs that actually achieve what the client wants to achieve. Learning the ins and outs of the human body can be1:tricky at first, particularly the HEALTHY language EATING is different from what you are used PART INTRODUCTION TO THEbecause HUMANmuch BODYof AND to hearing. It is useful to ‘practise as you learn’; for example, think about the bones and joints that are being moved, and which muscles are moving them, when you train. Think about how this differs from one exercise to the next. It is also vital that you understand the functions of the body’s systems. When you develop fitness programs, think about how long it will take a client’s cardiovascular system to improve so that the The study anatomy andkilometre physiology very that important whenoflearning how tohuffing instructand fitness clients. person canofrun that extra orisclimb extra flight stairs without puffing. All Without the body works, youreally will be unable to plan and instruct effective fitness programs the bodyknowing systems how are interlinked, and one does not function well without the others. Muscles rely that actually wants to achieve. Learning the ins and outs of the human body on oxygen toachieve do theirwhat work.the Theclient cardiovascular system needs to pump that oxygen around the body in can be tricky at first, particularly because much of the language is different from what you are used the blood. The respiratory system needs to take in that oxygen from the air. The nervous system needs to hearing. is useful toto‘practise you learn’; for example, think about the bonesofand are to signal theItbody parts do theiras job, and the digestive system is the cornerstone thejoints bodythat getting being moved, and which muscles are moving them, when you train. Think about how this differs from the energy it needs. one exercise to the next. It is also vital that you understand the functions of the body’s systems. When you develop fitness programs, think about how long it will take a client’s cardiovascular system to improve so that the person can run that extra kilometre or climb that extra flight of stairs without huffing and puffing. All 1 Choose three weight-training exercises. List the muscles, movements and joints that are used in the body systems are interlinked, and one really does not function well without the others. Muscles rely them. on oxygen to do their work. The cardiovascular system needs to pump that oxygen around the body in 2 List the three planes of the body and identify the regions that are formed by each plane. the blood. The respiratory system needs to take in that oxygen from the air. The nervous system needs 3 Explain the role of the cardiovascular system and any changes that may occur in it due to training. to signal the body parts to do their job, and the digestive system is the cornerstone of the body getting 4 Explain the role of the digestive system and any changes that may occur in it due to training. the energy it needs. 5 What is blood pressure? Identify: a the two measurements that are taken b what is occurring when the two measurements are taken c the immediate effect on blood pressure of an exercise session 1 Choose three weight-training exercises. Listpressure. the muscles, movements and joints that are used in d a long-term effect of training on blood them.muscle fibre adaptations are likely to occur as a result of the following? 6 What 2 a ListAerobic the three planes of the body and identify the regions that are formed by each plane. training 3 Explain the role of the cardiovascular system and any changes that may occur in it due to training. b Strength training (high-weight, low repetitions) 4 c Explain the role of theresistance digestive system any changes that may occur in it due to training. Endurance-based trainingand (low-weight, high repetitions). 5 What What is is the blood pressure? Identify: 7 function of the digestive system, and what are the main structures of the system? a the twothe measurements that are taken 8 How does body produce energy? Identify the three methods of energy production. b what is occurring when the two measurements are taken 9 What are the limiting factors to continued exercise? c the immediate effect on blood pressure of an exercise session d STUDY a long-term CASE 1.1 effect of training on blood pressure. 6 muscle 42-year-old fibre adaptations arewants likely to to decrease occur as body a result following? Joe What is an inactive man who fat of andthe increase muscle mass to be stronger andalookAerobic better. training b Strength low repetitions) 1 What type of training exercise (high-weight, would you prescribe for Joe? c Endurance-based resistance repetitions). 2 Explain which body systems wouldtraining be used(low-weight, for each typehigh of training you prescribe. 7 What is the function of the digestive system, and what are the main structures of the system? 8 How does the body produce energy? Identify the three methods of energy production. CASE STUDY 1.2 9 What are the limiting factors to continued exercise? Jan is 25 years old and gave birth to her first child six months ago. She experienced mild lower-back pain CASE 1.1 which has failed to subside since the birth of her baby. Her physiotherapist has during STUDY her pregnancy, recommended that42-year-old she commence a strengthening program for the muscles supporting lower back. Joe is an inactive man who wants to decrease body fat and increase muscleher mass to be stronger 1 Research suitable exercises for Jan to achieve her goals, assuming that the physiotherapist supports this and look better. approach. 1 What type of exercise would you prescribe for Joe?

Chapter summary

Review questions

• Test your knowledge and consolidate your learning through the Review questions. Review questions

2

Explain which body systems would be used for each type of training you prescribe.

• Analyse in-depth Case studies that present fitness issues in context, encouraging you to 3:11 PM integrate and apply the concepts discussed in the chapter to the workplace. CHAPTER 1 CASE STUDY 1.3 Suzie is an office worker who spends her working day on a computer. She experiences neck and thoracic pain at work when she works at her computer for at least six hours per day. Her doctor has referred her to a chiropractor to assess possible kyphosis, develop a management strategy to assist her condition and possible strategies that may help her pain at work. CHAPTER 1 The chiropractor has identified that the following muscles require an endurance-training program to Anatomy and physiology cope with Suzie’s workload: • Rhomboids CASE STUDY 1.3 • Posterior deltoid • Middle lowerworker trapezius Suzie is antooffice who spends her working day on a computer. She experiences neck and thoracic •painErector at workspinae when she works at her computer for at least six hours per day. Her doctor has referred her to a • Transverse abdominis chiropractor to assess possible kyphosis, develop a management strategy to assist her condition and possible • Internalthat oblique. strategies may help her pain at work. The identified the following muscles willan require a stretching program: The chiropractor chiropractor has has also identified that that the following muscles require endurance-training program to • Iliopsoas cope with Suzie’s workload: Pectorals •• Rhomboids Upper trapezius •• Posterior deltoid •• Anterior Middle todeltoid. lower trapezius Provide spinae Suzie with a home exercise program to help improve her posture. (You may need to refer to content •1 Erector from other chapters in this book.) • Transverse abdominis Suggest oblique. some strategies that may help Suzie while she is at work on her computer. Think about the •2 Internal practical set-up of thealso computer andthat some can dowill while at work. The chiropractor has identified theexercises followingshe muscles require a stretching program: • •

Iliopsoas Pectorals

• • Upper Start your onlineWeblinks reading and research trapezius • Anterior deltoid. Get Body Smart 1 Provide Suzie with a home exercise program to help her posture.websites (You may need to refer to content using the short list ofimprove useful or https://www.getbodysmart.com/ from other chapters in this book.) body’ 2Healthline: Suggest ‘The somehuman strategies that may help Suzie while she is at work on her computer. Think about the online resources. https://www.healthline.com/human-body-maps practical set-up of the computer and some exercises she can do while at work. Introduction to anatomy & physiology: Crash course A&P #1 (video) https://www.youtube.com/watch?v=uBGl2BujkPQ&list=PL8dPuuaLjXtOAKed_MxxWBNaPno5h3Zs8

Weblinks

Get Body Smart https://www.getbodysmart.com/ Healthline: ‘The human body’ https://www.healthline.com/human-body-maps Introduction to anatomy & physiology: Crash course A&P #1 (video) https://www.youtube.com/watch?v=uBGl2BujkPQ&list=PL8dPuuaLjXtOAKed_MxxWBNaPno5h3Zs8

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CASE STUDY 1.2 Jan is 25 years old and gave birth to her first child six months ago. She experienced mild lower-back pain during her pregnancy, which has failed to subside since the birth of her baby. Her physiotherapist has recommended that she commence a strengthening program for the muscles supporting her lower back.

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Guide to the online resources FOR THE INSTRUCTOR Cengage is pleased to provide you with a selection of resources that will help you prepare your lectures and assessments. These teaching tools are accessible via cengage.com.au/instructors for Australia or cengage.co.nz/instructors for New Zealand. MINDTAP Premium online teaching and learning tools are available on the MindTap platform - the personalised eLearning solution.

MindTap is a flexible and easy-to-use platform that helps build student confidence and gives you a clear picture of their progress. We partner with you to ease the transition to digital – we’re with you every step of the way. The Cengage Mobile App puts your course directly into students’ hands with course materials available on their smartphone or tablet. Students can read on the go, complete practice quizzes or participate in interactive real-time activities.

MindTap for Marchese’s Essential Guide to Fitness for Fitness Instructors is full of innovative resources to support critical thinking, and help your students move from memorisation to mastery! Includes: • Marchese’s Essential Guide to Fitness for Fitness Instructors eBook • Polling activities, labelling activities, interactive quizzes and more MindTap is a premium purchasable eLearning tool. Contact your Cengage learning consultant to find out how MindTap can transform your course.

MAPPING GRID The Mapping grid is a simple grid that shows how the content of this book relates to the units of competency needed to complete the Certificate III in Fitness SIS30315

INSTRUCTOR’S GUIDE The Instructor’s guide provides detailed solutions to every question in the text.

COGNERO TEST BANK A bank of questions has been developed in conjunction with the text for creating quizzes, tests and exams for your students. Create multiple test versions in an instant and deliver tests from your LMS, your classroom, or wherever you want using Cognero. Cognero test generator is a flexible online system that allows you to import, edit, and manipulate content from the text’s test bank or elsewhere, including your own favourite test questions. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

GUIDE TO THE ONLINE RESOURCES

POWERPOINT™ PRESENTATIONS Cengage Premium PowerPoint lecture slides are available as an optional, purchasable, instructor resource to provide you with additional teaching support. These resources are a convenient way to add more depth to your lectures, covering additional content and with an exclusive selection of engaging features aligned with the textbook including online video activities, discussion questions, instructor notes and mapping to the training package. Contact your Cengage learning consultant to find out more. Complimentary Basic PowerPoint slides are still available to instructors when this textbook is prescribed as a course resource.

ARTWORK FROM THE TEXT Add the digital files of graphs, tables, pictures and flow charts into your course management system, use them in student handouts, or copy them into your lecture presentations.

FOR THE STUDENT

MindTap is the next-level online learning tool that helps you get better grades! MindTap gives you the resources you need to study – all in one place and available when you need them. In the MindTap Reader, you can make notes, highlight text and even find a definition directly from the page. If your instructor has chosen MindTap for your subject this semester, log in to MindTap to: • Get better grades • Save time and get organised • Connect with your instructor and peers • Study when and where you want, online and mobile • Complete assessment tasks as set by your instructor When your instructor creates a course using MindTap, they will let you know your course key so you can access the content. Please purchase MindTap only when directed by your instructor. Course length is set by your instructor.

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PREFACE It’s so exciting to see the fitness industry continue to evolve. With more 24-hour gyms, a growing number of specialised franchises and the continuously growing online-fitness phenomenon, things have definitely changed in the fitness industry since the first edition of this textbook was published. As educators and professionals who work closely with a very active population, we see lots of injuries that could have been prevented quite easily with more strength, fitness or flexibility. This textbook is your first tool for building an amazing career in fitness. How you set yourself apart from the rest will be largely built around your knowledge and skills. Learn as much as you can and apply it as you go. You will find that this textbook has been designed with that in mind. Practice makes perfect, so, rather than rote-learn, keep applying what you learn along the way. Keep fit yourself. Be familiar with the entire industry, but don’t limit yourself there. Work closely with other personal trainers and fitness instructors, and take the time to talk about clients to make sure the best outcome for them is achieved. Setting an example in the fitness industry starts here. We truly hope that this book is a great tool to help you get started. Best wishes for a great career. Keep fit and make it count! Rosemary Marchese Julie Taylor Kirsten Fagan

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ABOUT THE AUTHORS Rosemary Marchese is one of Australia’s leading fitness educators, with over 20 years’ experience in the fitness and health industries. She is the owner of Max Sports Physiotherapy Clinic, and specialises in treating sports injuries, scoliosis and neck and back problems. She is a highly recognised author and writer. She has worked first-hand with the general public as a fitness instructor, a personal trainer and a group-exercise instructor. She has over two decades of experience ‘behind the scenes’ in fitness, including having consulted and written the standards for the entire Australian fitness industry. She was also part of the team that updated Sports Medicine Australia’s pregnancy and exercise position statement. Rosemary has extensive experience in developing learning, assessment and curriculum materials for both private and public institutions. Rosemary is the author of two award-winning textbooks, including this text. She is also the author of The Fit Busy Mum: Seven Habits for Success. In her spare time, she loves to spend time with family and friends, exercise and read. Julie Taylor is a passionate educator in the fitness industry with extensive teaching and lecturing experience at high schools, TAFE NSW and the University of Technology Sydney. During her career she has received multiple awards, including for Excellence in Teaching and Learning and Innovation in Teaching. This can be attributed to her practical experience as a personal trainer (in Los Angeles, the Lake Louise Ski Resort in Canada, and Sydney) and her formal qualifications in Education and Learning Design. In the sporting field, Julie has worked for the Sydney Organising Committee for the Games of the XXVII Olympiad (SOCOG) and in accreditation, and has managed New South Wales state water polo teams, including two bronze-medal teams at the National Championships. Her more recent experience is as an Instructional Designer in Learning Technology and Educational Excellence at TAFE NSW. She has developed a virtual-reality orientation app for the Certificate III in Fitness course and numerous online blended learning resources, including videos and interactive tools for fitness. Julie’s passion is to develop learners into fitness instructors who can make health and fitness enjoyable and safe, and to encourage participation in fitness and sport for life.

Contributing author Kirsten Fagan has been involved in the health and fitness industry for over 25 years. A personal trainer for the past 15 years, Kirsten’s passion for fitness developed from her own professional basketball career within Australia, Europe and the US. Kirsten has also worked extensively with primary-, high-school and graduate students, having been Head of PE and Health at Haileybury private college in Melbourne, as well as lecturing in many universities, registered training organisations and vocational training organisations around Australia and the US. Her current role is Manager of Sport, Recreation, Fitness, Massage, Allied Health Nutrition, Complementary Health and Beauty Services at Holmesglen Institute. Kirsten’s passion is education; if we can educate correctly, we can prevent many long-term illnesses and health concerns. Her primary goal is to help you learn as much as you can about the health and fitness industry so that you can apply the concepts you learn to achieve your clients’ goals, as well as your own personal goals! Kirsten’s hobbies are keeping fit, coaching basketball and her family. She has two beautiful children, a personal trainer/chef husband and a close extended family who live in all areas of the world – her daily life is busy but exciting! Her favourite saying, attributed to Fred DeVito, is, ‘If it doesn’t challenge you, it doesn’t change you!’ Kirsten worked on Chapters 5–9 and 17 of this edition.

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ACKNOWLEDGEMENTS From Rosemary: In a very busy life, these kinds of massive projects cannot be completed alone. They could never be completed without the support of my family, who put up with my long hours as I get these types of projects finished. Anthony, Giacomo, Alessia and Mia: you are my world. Thank you to my two co-authors, Julie and Kirsten, who stepped up and helped out with this edition. Your knowledge, experience and commitment are always inspiring, and I am grateful that we have brought you into the team for this edition. From Julie: As a full time working mum, I would like to thank my husband, Chris, and my two boys, Nick and Mitch, for their unconditional support and inspiration. As a family, they have been there through the juggling of time after work to collaborate on and write this textbook and have emotionally supported me during the recent loss of my mother while I was overseas. My family is passionate about sport and fitness and have always managed to incorporate physical activity into their very busy lives. I dedicate my contribution to this textbook to them. Many thanks to Rosemary and to Cengage for inviting me to be a collaborator on this amazing project and producing a valuable resource for future fitness instructors. From Kirsten: This work would not have been possible without the amazing support of my family and friends. I am especially indebted to Ms Christine McDougall of Queensland Health, who has been supportive of both my career and my personal goals, and who has worked actively to provide me with the ability to achieve these dreams. I am grateful to all of those with whom I have had the pleasure to work during this and other related projects, including Holmesglen Institute, which strives actively to make education a better learning experience for everyone. No one has been more important to me in the pursuit of this project than the members of my family. I would like to thank my parents, whose love and guidance are with me in whatever I pursue. They were the ultimate role models. Most importantly, I wish to thank my loving and supportive husband, Philip, and my two wonderful children, Sitaya and Jayveon, who provide unending inspiration. The authors would also like to thank Sophie Kaliniecki, Laura Di Iorio and the rest of the team at Cengage for their professionalism and support throughout this process. Cengage would like to thank the following manuscript reviewers:

• • • • • • • • • • •

Caron Daly, iCollege Dane Ivicevic, TAFE WSI and Open Colleges Patricia Cooper, Randwick College – TAFE NSW Sean Law, North Sydney Institute – TAFE NSW Jessica Halpin, TasTAFE Penny Dyer, TasTAFE Mark Cudmore, Southwest Sydney Institute – TAFE NSW Stewart Cooke, The College of Health and Fitness Emma Hunter, Academy of Fitness Ar’e Abera, Western Riverina Community College Maria Noonan, TAFE QLD – Gold Coast.

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ACKNOWLEDGEMENTS

Cengage would also like to thank the following people for their assistance with last edition’s photoshoot:

• • • •

Laura May Grogan (photographer) Kristy Pattinson (subject-matter expert) The proprietors of Genesis Gym, Ringwood (location) Rosemary Batten and Aaron Chen (models).

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PART 1 Introduction to the human body and healthy eating

CHAPTER 1 Anatomy and physiology CHAPTER 2 Nutrition

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CHAPTER

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Anatomy and physiology

OBJECTIVES This chapter involves application of the following topics: 1.1 Anatomical and physiological principles and terminology 1.2 The structural organisation of the human body 1.3 The structure and function of the musculoskeletal system 1.4 The structure and function of the cardiovascular and respiratory systems 1.5 The structure and function of the nervous system 1.6 The structure and function of the digestive system 1.7 The body’s energy systems that are relevant to fitness programs.

LO

INTRODUCTION Anatomy The study of the structure of organisms Physiology The study of the function of living organisms

The study of the anatomy and physiology of the human body is a fascinating journey of discovering all the parts of the body and how they work. As a fitness instructor, it is important to understand the structure and function of the human body so that you can use this information to develop effective exercise programs and minimise the risk of injury to your clients. For example, you need to know what movements the muscles can perform in order for you to develop a fitness program for your clients. Before commencing, it is useful to understand the meaning of the terms ‘anatomy’ and ‘physiology’. Anatomy is the study of the structure of living organisms and how each part relates to another. Physiology is the study of the function of living organisms. Later in this chapter, we will investigate the structural organisation of the human body.

1.1  ANATOMY AND PHYSIOLOGY PRINCIPLES AND TERMINOLOGY In order to prescribe a fitness program, it is important that you understand the terminology used in the fitness industry.

Anatomical position The human body standing in the erect position, with arms by the sides and the palms facing anterior, and the feet parallel so that the toes and head face forwards

Anatomical position Describing the direction and movement of the human body is like learning a new language. To simplify the process, there must be a reference point from which all things are described. For example, whether the elbow is above or below the hand will depend on whether or not the elbow is bent. The reference point used is called the anatomical position. The anatomical position is the human body standing in the erect position, arms by the sides with the palms facing anterior (towards the front, as seen in Figure 1.1) and feet parallel so that the toes and head face forwards.

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CHAPTER 1 Anatomy and physiology

Prone and supine positions Lying face-down is called the prone position, and lying face-up is called the supine position, as seen in Figures 1.2 and 1.3.

Prone Lying face-down

Planes of body motion

Supine Lying face-up

To help describe movement, the body can be divided into many planes of motion. The three basic types of planes in reference to the human body are the sagittal, frontal (coronal) and transverse (horizontal) planes, as seen in Figure 1.4. The sagittal plane passes through the body from anterior (front) to posterior (back) and divides the body into left and right parts. See Figure 1.5(a). The frontal plane passes through the body from lateral to medial (ear to ear) and divides the body into anterior and posterior parts. See Figure 1.5(b). The transverse plane passes through the body level with the horizon and divides the body into superior (upper) and inferior (lower) parts. See Figure 1.5(c).

Sagittal plane Divides the body into a left and right section

Directional terminology Table 1.1 lists terms that are often used in anatomy and physiology. Always remember to use the anatomical position when describing direction and movement, unless otherwise Figure 1.1 The anatomical specified. You can check your knowledge of this anatomical position – anterior view terminology in Workout 1.1.

Figure 1.2  The prone position

Figure 1.3  The supine position

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Frontal plane Divides the body into anterior (front) and posterior (back) sections Transverse plane An imaginary horizontal line through the body dividing it into superior and inferior sections Superior Towards the head (e.g. the eyes are superior to the nose) Inferior Towards the feet (e.g. the teeth are inferior to the nose)

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

a

b

c

Figure 1.4 Planes of body motion: (a) sagittal plane; (b) frontal (coronal) plane; (c) transverse (horizontal) plane

b

a Extension

Flexion

Flexion

Flexion

Extension Extension

Flexion

Extension

c

Figure 1.5  (a) Movements in the sagittal plane; (b) movements in the frontal plane; (c) movements in the transverse plane Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

CHAPTER 1 Anatomy and physiology

Table 1.1 Directional terms and definitions Superior

Towards the head – e.g. the eyes are superior to the nose

Inferior

Towards the feet – e.g. the teeth are inferior to the nose

Anterior

Towards the front of the body – e.g. the belly button is anterior to the spine

Posterior

Towards the back of the body – e.g. the spine is posterior to the stomach

Medial

Towards the midline of the body – e.g. the nose is medial to the ears

Lateral

Towards the side of the body – e.g. the arms are lateral to the nose

Proximal

Towards the attachment point of a limb – e.g. the elbows are proximal to the wrists

Distal

Away from the attachment point of a limb – e.g. the elbows are distal to the shoulders

Superficial

Towards the surface of the body – e.g. skin is superficial to the kidneys within the body

Deep

Towards the inside of the body – e.g. the stomach is deep to the skin

Unilateral

On one side of the body only – e.g. performing a biceps curl with the right side only is a unilateral biceps curl

Bilateral

On both sides of the body – e.g. performing a biceps curl with both arms is a bilateral biceps curl

Contralateral

On the opposite side of the body – e.g. much of the brain supplies messages to the contralateral side of the body, with the right side of the brain supplying the left side of the body and the left side of the brain supplying the right side of the body

Palmar

On the same side as the palm of the hand – e.g. when drinking from a cup, the cup will be in contact with the palmar surface of the hand

Plantar

On the same surface as the sole of the foot – e.g. the plantar surface of the foot makes contact with the ground

Dorsal

On either the back or back (top) of the foot – e.g. a dropped weight can fall on the dorsum of the foot

Ventral

On the front or belly of the body – e.g. the chest is ventral

Movement terminology During training, the human body moves in many different ways, and this is achieved by our muscles contracting and pulling the bones across a joint. Different joints in the body are able to achieve different degrees of movement. Some joints, such as the shoulder joint (a ball-and-socket joint), can move in many different directions, while others, such as the elbow (a hinge joint), are much more limited in the movement directions available. Joints will be discussed further later in this chapter. For now, think of it this way: a joint is a meeting point between two bones, and the muscles will force the bones to move so that joints can bend and move limbs in all sorts of directions. Those movements have special names, and it is important that you get to know these terms and the muscles responsible for the movements involved (see Figure 1.6).

Applications to fitness training When designing a fitness program for your client, you will need to consider the planes of motion through which you want your client to work. Current schools of thought for training of the general population tend towards making training as functional as possible for as many people as possible. This involves moving clients through all the planes of motion that are relevant to everyday life, fitness, activities and sports.

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

(a)

(c) (d)

(b)

(a) Flexion: To decrease the angle at a joint (to bring the body part in towards the centre of the body, usually in the sagittal plane) (b) Extension: To increase the angle at a joint (to bring a body part away from the centre of the body, usually in the sagittal plane)

(c) Abduction: To increase the angle of a limb away from the body in a frontal plane (d) Adduction: To decrease the angle of a limb away from the body in a frontal plane

(e)

(f)

(e) Lateral/external rotation: To rotate a limb outwards, around the long axis of a bone (f) Medial/internal rotation: To rotate a limb inwards, around the long axis of a bone

Circumduction: To allow a joint to perform movement through all possible axes, combining flexion, abduction, extension and adduction

Figure 1.6 Movement terminologies Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

CHAPTER 1 Anatomy and physiology

Protraction: To bring a body part forwards or to protrude a body part such as the mandible (jaw bone) or scapula (shoulder blade)

Elevation: To lift a body part

Retraction: To bring a body part backwards or to retract a body part such as the mandible or scapula

Depression: To lower a body part

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

Supination: To turn the palm anterior

Pronation: To turn the palm posterior

Inversion: To turn the sole of the foot medially

Eversion: To turn the sole of the foot laterally

Dorsiflexion: To bring the toes upwards at the ankle

Plantarflexion: To bring the toes downwards at the ankle

Figure 1.6 (CONT.)

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CHAPTER 1 Anatomy and physiology Functional training involves movement based on real-world situations and biomechanics. It involves movements in multiple planes and using multiple joint movements. It is training that enhances the coordinated working relationship between the nervous and musculoskeletal systems so that they can perform functional activities such as climbing and lunging. In contrast, traditional resistance training programming was often based on that of the bodybuilders who spent countless hours in gyms focusing on only one body part at a time. These isolation exercises can definitely still form part of a training program, but they are not a great use of a client’s session time if the client’s time is limited and their aim is to achieve a ‘whole-body’ workout. While isolation exercises still have their merits, there is now a shift towards the general population benefitting from whole-body, more functional exercises to gain maximum benefit and be time-efficient. More detail on resistance training is provided later in this chapter and in Chapters 5 and 6. For example, a freestanding lunge with lateral (to the side) bent-arm raises will work the quadriceps, hamstrings, gluteals and calf muscles in the lower half of the body while simultaneously working the deltoids in the upper body. And this is only the beginning! While muscles are working to make this movement occur, there are also many muscles working to stabilise the body so that you do not fall over. For example, the deep abdominal and back muscles are contracting in an isometric fashion to keep you stable. An example of a functional training approach is that squat practice is more likely to help an older client to be able get up from a couch than leg-extension exercises on a machine in a fitness facility. The squat, as opposed to the leg extension, can also help with this client’s balance and strength, and is similar to the movements that are useful for everyday mobility. For optimal results at a task, you must practise that task! So if you want your client to improve their ability to get up from a couch, they must practise getting up from a couch. However, isolation-type exercises may still be useful to help to improve any weak links in the client’s body. It’s interesting that the training that traditionally occurred in gyms had a history based around bodybuilding, yet a majority of the population did not want to look like a bodybuilder. You will find that many of your clients will benefit most from exercises that work through two to three planes of motion, are relevant to their goals and lifestyles, challenge their dynamic stabilisation and are mostly in an upright position. Weight-bearing exercises, such as running and walking, will tend to use more energy relative to non-weight-bearing exercises, such as swimming, because weight-bearing exercise involves holding your body upright against gravity. Think about the body as comprising many segments and joints, all connected as a kinetic chain. Maximum results are most likely to occur when you integrate the body by challenging the muscles, skeleton and nervous system simultaneously.

Functional training A type of exercise in which the activities revolve around training the body in a manner applicable to functions in daily life Isolation exercises Exercises that focus on one muscle group

Contra-indications and precautions A contra-indication to exercise testing or exercise prescription means that the client should not undertake the task for safety reasons and should be referred to an appropriately qualified health professional, usually a general practitioner (GP) or allied health professional, who will then refer the client to other health professionals, if necessary. A relative or temporary contra-indication (sometimes known as a precaution) may mean that the risks associated with the exercise could outweigh the benefits. There are screening tools and procedures to help you identify these contra-indications, more detail about which is provided in Chapters 3 and 4. Contra-indications to exercise testing and/ or exercise prescription may include, but are not limited to, some of the disorders of body systems listed later in this chapter in Table 1.6.

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Contra-indication A condition that makes exercise not helpful or even harmful Precaution A condition whereby you will need to take extra care to ensure client safety during exercise

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WORKOUT 1.1

PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

1 Explain the movements that are involved in a chest pass using a medicine ball. 2 Explain the movements used in the following exercises: a Biceps curl b Upright row machine c Lateral raise using dumbbells. 3 Circle or underline the correct answer using the skeletal and muscle diagrams in this chapter to help locate the relevant body part (the first has been completed to assist you): a The pectoralis major is anterior/posterior to the rhomboids. b The rectus abdominis is deep/superficial to the transverse abdominis. c The soleus inserts into the calcaneus via the biceps/Achilles tendon. d The lungs are deep/superficial to the pectoralis major. e The pectoralis is anterior/posterior to the rhomboids. f The radius is lateral/medial to the ulna. g The quadriceps is anterior/posterior to the hamstrings. h The heart is superior/inferior to the eyes. 4 What is the definition of ‘anatomical position’? What is its purpose? 5 Fill in the blanks using directional terminology. a The triceps is to the biceps. b The lungs are to the heart. c The ears are to the nose. d The femur is to the tibia. e The patella is to the tarsals. f The fingers are to the hands. g When standing in the anatomical position, the thumb is to the fingers. h The deltoid is to the rectus abdominis. 6 Use directional terminology to describe the following (the first one has been done for you): a The nose in relation to the mouth: superior b The ears in relation to the nose: c The nose in relation to the scapula (shoulder blade): d The arms in relation to the umbilicus (belly button): e The heart in relation to the stomach: f The hands in relation to the shoulders: g The elbow in relation to the wrist: h The patella in relation to the ankle: i The elbow in relation to the shoulder: j The hip in relation to the knee: k The hip in relation to the scapula: l The stomach in relation to the sternum (breastbone): m The patella (knee cap) in relation to the hip: . 7 Choose the correct answer. If someone is lying in the supine position, they are lying: a face upward b face downward c on their side d curled up in the foetal position. 8 In which planes do the following movements occur? a Flexion and extension b Abduction and adduction c Lateral flexion of the trunk d Trunk rotation. 9 For each of the planes of motion, list three resistance exercises that move through each plane and list at least one muscle that is used during that movement. For example, a biceps curl moves through the sagittal plane and trains the biceps brachii muscle.

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CHAPTER 1 Anatomy and physiology →

10 Research and compile a list of 10 exercises that could be considered functional by the fitness industry. Outline the benefits of each exercise, the potential risks, and the movements and planes of motion involved. 11 Research and list four resistance exercises that may help achieve the following goals: a An older adult wanting to be able to walk to the shop and back without feeling exhausted b A chef who has recently put on weight and has some back tightness c A gymnast who needs to increase shoulder strength d A busy mum who is time-poor and looking after her three toddlers, and who needs to lose 8 kg but can’t afford a gym e A client who needs to increase balance after a sprained ankle and has been cleared for exercise without modifications. 12 For each of the clients listed in question 11, research and compile a list of additional fitness advice you might give in regard to: a lifestyle and behaviour changes b additional fitness activities that may be appropriate for their goals c any healthcare practitioners that may be helpful in planning a program. 13 Research the following exercises and identify the muscles and movements used: a Leg curl b Calf raises c Sit-ups d Bench press. 14 Participate in a group fitness session and list five of the exercises you performed. Answer the following questions for each of those exercises: a What were the directions of movement involved (e.g. flexion and extension)? b What joints were being moved (e.g. the elbow joint)? c Would you consider the exercise functional? Why or why not? (Hint: Think about the planes of movement used during each movement.) 15 Challenge: play the Anatomical Directions and Positions game. To do so, follow the link https://www.purposegames.com/game/anatomical-directions-and-positions-game.

11

LEARNING SKILLS

1.2  THE STRUCTURAL LEVELS OF ORGANISATION IN THE HUMAN BODY The human body is composed of cells, which are the basic structural and functional units of living organisms. The cell is similar to a factory with lots of machines inside, and it needs to communicate both within itself and with the outside environment. Regardless of the cell type, all cells have the same basic parts and some common functions. Figure 1.8 depicts generalised cells with some of the features that are common to all cell types. Table 1.2 provides an overview of some of the different types of cells in the body. Each type of cell will look and act differently based on its intended purpose. The cell can react to chemical messengers, such as hormones and neurotransmitters found in body fluids. Combining the same types of cells results in tissue, such as muscle or bone tissue. Damage to the structure or function of muscle fibres can affect how the entire muscle functions. Two or more similar tissues make up organs, such as the heart and lungs. Organisms, such as the human body, are the combination of cells, tissues and organs that work together to promote life (see also Figure 1.7).

Organisms Living beings, and are made up of a combination of cells, tissues and organs that work together to promote life Hormones Chemical messengers produced by different endocrine organs Neurotransmitters Chemicals that are released at the ends of nerve cells to communicate the signals (messages) between nerve cells called neurons Muscle fibres Muscle cells

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

1

2

3

Chemicals Atoms combine to form molecules.

Cells Cells are made up of molecules.

Tissues Tissues consist of similar types of cells.

Smooth muscle tissue

4

5

6

Organs Organs are made up of different tissue combinations.

Body systems Body systems consist of different organs that work together to achieve bodily functions.

Organisms Organisms, such as humans, are made up of many body systems.

Epithelial tissue

Connective tissue

Smooth muscle tissue

Blood vessel (organ)

Cardiovascular system

Figure 1.7 The structural levels of organisation of the body

Table 1.2 Types of human body cells Tissues Combinations of similar cells Organs Structures of the body made up of two or more similar tissues, such as the heart or lungs

Type of cell

Cell variations

Functions

Bone cell

Osteocyte

Embeds within the osseous (bony) tissue to help give bone its structure. It reactivates at fracture sites to lay down new tissue and facilitate bone repair

Muscle cell

Cardiac, skeletal and smooth muscle fibres

Cardiac muscle is found in the heart, skeletal muscle is the muscle that attaches to bone and smooth muscle is found in internal organs such as the stomach. All three types of muscles have different functions, but essentially, all function to create movement

White blood cell

Leucocyte; phagocytes

Cells found in blood, forming part of the immune system to fight off infection and disease

Red blood cell

Erythrocyte

Responsible for delivering oxygen to the body tissues via the blood vessels. Note: Erythrocytes contain haemoglobin (iron-containing pigment), which carries oxygen from the lungs to the tissues. If haemoglobin is low, it causes anaemia, and may affect the function of tissues due to a lack of oxygen

Osteocytes Bone cells

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CHAPTER 1 Anatomy and physiology →

Type of cell

Cell variations

Functions

Fat cell

Adipocyte

A specialised connective tissue that manufactures and stores fat. It is vital in maintaining energy balance and storing energy in the form of lipids. This is achieved by secreting and mobilising energy sources in response to hormonal stimulation

Nerve cell

Neuron

Electrically charged cells that transmit information between different parts of the body through the use of electrical and chemical signals

Skin cell

Epithelial cell

Together, they form a protective barrier between delicate organs and the outside world. They also help to regulate the body temperature and keep out infection

The structure of the cell The cell membrane encloses all cell contents and can repair quickly when torn (see Figure 1.8). Cytoplasm is the cellular material inside the cell membrane and outside the nucleus. In a muscle cell, the cytoplasm is known as the sarcoplasm. This is the site where most cellular activities are accomplished. The nucleus is the organelle within the cytoplasm that contains the genes of the cell, and it is the control centre of the cell. The nucleus is what gives the cell the ability to duplicate. Most cells have only one nucleus; however, some, such as muscle cells (muscle fibres), have multiple nuclei. Mature red blood cells (erythrocytes) do not have a nucleus and therefore cannot repair themselves once they start to deteriorate. The human body needs to continually make new red blood cells to survive. The mitochondria are often referred to as the ‘power plant’ of the cell; they supply the body with most of its energy in the form of a molecule called adenosine triphosphate (ATP). ATP is the molecule that the body breaks down to release stored energy when needed. It is produced within the mitochondria through a series of chemical reactions known as the aerobic energy system. The aerobic system is heavily involved in producing energy during activities lasting longer than a few minutes. Cells that are packed with mitochondria, such as muscle cells, have high energy requirements. Increased

Cytoplasm The substance that surrounds the nucleus of a cell Nucleus The site containing genetic material for a cell Genes The basic units of heredity in a human being Erythrocytes Red blood cells Mitochondria The sites within a cell responsible for aerobic energy production

Nuclear envelope

Nucleus

Cell membrane The outer protective part of a cell

Mitochondrion

Cytoplasm

Cell membrane

Figure 1.8 The structure of a generalised cell

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14

Haemoglobin The protein in blood that carries oxygen from blood to the body tissues

PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

numbers of muscle mitochondria are largely responsible for the increased resistance to fatigue and the health benefits associated with aerobic exercise, such as running and cycling. It is important to have a basic understanding of the cell structure and energy provision because they relate to training modalities and positive adaptations to the body under exercise conditions. The energy requirements of training are also important to the fitness instructor when programming exercise for clients.

Haemoglobin

Metabolism The sum of the physical and chemical processes necessary to sustain life and provide energy to the body

Haemoglobin in blood carries oxygen from respiratory organs (the lungs) to the rest of the body (tissues). Here, oxygen is released to enable nutrients to be burned to provide energy for everyday functions. This process of ‘burning nutrients’ is known as metabolism and is a continuous process.

Myoglobin A protein found in heart and skeletal muscle tissues that is responsible for binding with oxygen and iron

Myoglobin

WORKOUT 1.2

Myoglobin is a protein found in heart and skeletal muscle tissues. It is responsible for binding with oxygen and iron. When you exercise, the muscles will use up the available oxygen. Myoblobin is only found in blood after muscle injuries. 1 Explain the differences between three different cell types and their functions. Describe an example of how these cells may change over time with an exercise program. 2 Explain the function of the following parts of a cell: a Cell membrane b Mitochondria c Nucleus. 3 Muscle cells contain lots of mitochondria and myoglobin. Research and explain the effects of endurance training on these components. 4 Research the effect and causes of low haemoglobin in the body and what you would do if your client showed signs and symptoms of low haemoglobin.

Types of tissues Connective tissue The supporting framework of the body that helps to support, bind or separate other body tissues

There are four types of tissues in the body: epithelia, connective tissue, nervous tissue and muscle tissue. These are explained in detail in Table 1.3. Connective tissue is found in various places within the human body. Examples of connective tissue that are of particular interest to fitness instructors include ligaments, tendons, fascia and cartilage.

Table 1.3 Types of tissues Tissue type

Function

Description

Epithelium

Protects the body from moisture loss, bacteria, radiation and physical trauma

There are two main types of epithelia. The first type covers or lines internal and external surfaces (e.g. the skin and the internal surface lining of the digestive tract). The second type, glandular epithelium, secretes hormones (chemicals that send signals around the body to create changes or maintain homeostasis) or other products, such as milk, saliva, sweat and acid.

Connective tissue

Provides structure and support to the body

Loose connective tissue holds body structures together (e.g. it holds the outer layer of the skin to the tissue beneath). Fibrous connective tissue holds body parts together, but it is strong and rigid compared to loose connective tissue. Fibrous connective tissue includes ligaments, tendons, cartilage and bone.

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CHAPTER 1 Anatomy and physiology →

Tissue type

Function

Description

Nervous tissue

Forms the nervous system, which is responsible for sending messages from the nervous system to the rest of the body, in the form of electrical signals

The nervous system is made up of the brain, the spinal cord and nerves. The basic structural unit of the nervous system is a neuron. A neuron contains a cell body, dendrites and an axon.

Muscle tissue

Contracts to create movement and heat

There are three types of muscle tissue: cardiac (found in the heart), smooth (that lines the walls of blood vessels and organs such as the digestive system) and skeletal (that attaches to bones and causes movements of the body).

Ligaments Ligaments are very important to the structure of a joint (where two bones meet), functioning to connect bone to bone and provide stability to the joint. For example, the medial collateral ligament of the knee connects the femur (the long bone in the thigh) to the tibia (the shin bone) and helps to provide knee stability. Ligaments are prone to injury (partial or complete tears) if a joint is forced too far in a particular direction. Ligaments can adapt to increases or decreases in mechanical loading by adjusting their size, material properties or both, but they have a limited blood supply and can take a long time to heal. The composition of ligaments allows them to contribute to restriction of movement; however, they are also slightly elastic, allowing you to gradually lengthen them in a flexibility program.

Ligaments Connective tissue that joins bone to bone

Tendons Tendons attach skeletal muscle to bone. For example, the Achilles tendon attaches the gastrocnemius (calf muscle) to the calcaneus (heel bone). Tendons have to withstand transversal and rotational forces as well as contusions (bruises) and other pressures. Sometimes they just do not cope and are susceptible to overload injuries where they partially or completely tear, at times even taking some bone with them (commonly known as an avulsion fracture). Like ligaments, tendons have a poor blood supply, and recovery from injury can therefore be slow. Exercise, growth and injury can place severe stress on the spot on the bone where the tendon connects (either the origin or insertion point). The bone responds with overgrowth, and this is where you find some prominent bony landmarks – for example, the greater tubercle. More research is needed to confirm the exact effects of training on tendons, but it appears that the effects of rest and immobilisation tend to be less severe on tendons than on muscle.

Tendons Connective tissue that joins muscle to bone Origin The more fixed end or attachment of a muscle to a bone (compared to insertion) Insertion The end of the muscle that is attached to the bone that moves

Fascia Fascia is a special type of connective tissue. There are two types of fascia: superficial fascia, which lies beneath the skin and permits free movement of the skin, and deep fascia, which covers and separates layers of muscles. Fascia provides the body with a network to connect many structures of the body. It allows forces to be transmitted through body segments to allow for smooth movement.

Fascia The type of connective tissue forming layers around different tissues of the body

Cartilage Cartilage is a type of connective tissue that manages tension and compression. It varies in form depending on location and function (see Figure 1.9). It is tough but flexible, and lacks nerve fibres. Cartilage receives its nutrients from a diffusion process whereby the surrounding blood vessels ‘pass over’ the required nutrients.

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Cartilage A type of connective tissue

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

Knee

Lower leg

Spine

Medial gastrocnemius

Lateral gastrocnemius

Ligament

Achilles tendon Invertebral disc (made of fibrocartilage) Calcaneus

Cartilages in external ear

Cartilages in nose

Articular cartilage of a joint Costal cartilage Cartilage in intervertebral disc

Pubic symphysis

Meniscus (padlike cartilage in knee joint) Articular cartilage of a joint Hyaline cartilages Elastic cartilages Fibrocartilages

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17

CHAPTER 1 Anatomy and physiology There are three types of cartilage in the body. Hyaline cartilage has a glassy appearance and is found at many joint surfaces. It functions to reduce the friction at joints. It is also found in parts of the respiratory system (the nose, larynx, trachea and bronchi). It contains no nerves or blood vessels. Hyaline cartilage that is found at the end of long bones is also known as articular cartilage and is deformable and elastic, which allows it to recover quickly after movement. Having articular cartilage at a joint reduces friction compared to bone-on-bone contact. For example, the ribs and sternum have articular cartilage at the ends of the bones, which facilitates free movement when breathing. Osteoarthritis involves damage to the articular cartilage at the ends of long bones. This results in a less smooth surface for the bones to glide across one another, which is why osteoarthritis is associated with pain and disability. Elastic cartilage is found in the external ear, the larynx and the epiglottis. Its main purpose is to provide support and some protection. Fibrocartilage is made of a denser arrangement of fibres to provide cushioning at the joints. It is found in the intervertebral discs, which sit between the bones in the spine (vertebrae) and at the pubic symphysis (where the two pubic bones meet anteriorly). 1 Research the following parts of the body and then match the appropriate tissue example to its tissue type. An example is provided to assist you. Tissue example

Hyaline cartilage A type of cartilage found on many joint surfaces and in various other places Osteoarthritis A degenerative joint disease that causes pain in the affected joints Elastic cartilage A type of cartilage found in the ears and throat Fibrocartilage The type of cartilage found in the intervertebral discs

WORKOUT 1.3

Tissue type

Achilles

Cartilage

Intervertebral disc

Ligament

Medial collateral Plantar

Tendon Ligament

2 Research what a meniscus tear in the knee is. a What type of tissue is damaged? b Explain how a meniscal tear can limit movement. 3 Provide an example of a ligament in the body. To what joint does it provide stability?

Organs An organ is made up of similar tissues that perform one or more functions when they work together. Some of the major organs and their locations and functions are explained in Table 1.4.

Table 1.4  Major body organs and their functions Organ

Functions

Brain

Part of the nervous system, controlling the actions of all the body

Spinal cord

A long, thin bundle of nervous tissue and support cells that, when combined with the brain, make up the central nervous system. Functions to conduct motor and sensory information from and to the brain, and also to coordinate certain body reflexes

Bones

Rigid organs that support and protect organs of the body, produce red and white blood cells and store minerals

Skin

The largest organ of the body, it protects all the inner body organs from damage and infection

Lungs

Take in oxygen and remove carbon dioxide from the body through the act of breathing

Heart

Responsible for pumping blood around the body to allow oxygen to reach the body organs and waste products to be pumped through to the lungs via the blood

Liver

Receives blood full of products that are the result of digestion in the gut. Stores some of the foods and delivers the rest to the other cells through the blood

Spleen

Responsible for producing the red and white blood cell pulp. Also contributes significantly to the immune system

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING



Organ

Functions

Kidney

Humans have two kidneys, which remove the waste products from the blood by regulating water fluid levels. Responsible for producing urine, which contains waste to be excreted by the body

Stomach

Carries out the physical and chemical digestion of food. The stomach muscles contract to physically digest the food. Chemicals (enzymes) released from the glands in the walls of the stomach help to chemically break down the foods

Bladder

Receives urine from the kidneys before urination

Skeletal muscles

Connecting bones to other bones, the skeletal muscles function to move bones and produce heat

Large intestine

Largest part of the digestive system. Absorbs water from digested food matter and then passes on any unwanted materials (waste) in the form of faeces via the anus

Small intestine

The part of the gastrointestinal tract where most of the digestion and absorption of food takes place

Pancreas

Gland that produces several important hormones, such as insulin and glucagon. It is also a digestive organ that secretes digestive enzymes to help further break down carbohydrates, proteins and lipids

Liver

Involved in regulating the body’s metabolism. Also clears toxins from the body

Gall bladder

A small organ where bile is stored and released into the small intestine when needed. Bile is a dark-green to yellow-brownish fluid produced by the liver and is used to digest lipids (fats) in the small intestine

Body systems Many organs work together within a single body system. For example, blood vessels and the heart work within the cardiovascular system to supply blood throughout the body. When we exercise, we use multiple body systems at the same time, and through training we can increase our efficiency to perform exercise and tasks. A summary of the functions of some major body systems is provided in Table 1.5 (see also Figure 1.10). Remember that earlier we mentioned contra-indications and precautions to exercise and that some body-system disorders may alter your care of your client. See Table 1.6 for a sample of body-system disorders.

Muscular

Skeletal

Circulatory

Digestive

Respiratory

Nervous

Figure 1.10 Human body systems

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CHAPTER 1 Anatomy and physiology

Table 1.5 The components and functions of human body systems Body system

Components

Function

Muscular

Skeletal, cardiac and smooth

Movement

Skeletal

Bones and parts of joints, such as cartilage

Support, protection, movement, calcium storage and blood-cell formation

Circulatory

Heart, arteries, veins and capillaries

Pumps and transports blood and lymph throughout the body

Digestive

Alimentary canal (gastrointestinal tract) and accessory digestive organs

Gastrointestinal tract digests food (breaks it down to smaller pieces) Digestive organs and glands further contribute to the digestive processes

Respiratory

Lungs, bronchi and alveoli

Takes in oxygen from the atmosphere and rids the body of wastes

Nervous

Nerves, brain and spinal cord

Uses electrical impulses to be the fastest communication system of the body

Table 1.6 Body-system disorders Body system

Body-system disorders

Skeletal system

• Osteoporosis: Causes bones to be brittle and prone to fracture • Postural abnormalities: Can make ligaments and muscles overstretched and weak; opposing muscles and ligaments become tight • Ligament sprains: Partial or complete tears in a ligament; result in joint dysfunction and pain • Osteoarthritis: Destruction of articular cartilage in joints leading to joint pain, stiffness and swelling • Rheumatoid arthritis: An autoimmune disease in which the immune system attacks the synovial lining of synovial joints, causing pain and inflammation. Ligament damage, bone erosion and joint deformity result

Muscular system

• Disorders of skeletal muscle: Can be caused by changes to the muscle fibre itself and also by changes to the nervous system • Muscle and tendon strains: Partial or complete tears in muscles, usually caused by some sort of physical exertion beyond the coping capacity of that muscle • Metabolic diseases: Can include thyroid and certain endocrine (hormonal) diseases. Can also be associated with muscular symptoms

Nervous system

• Nervous system disorders: Can occur in the central nervous system (brain and spinal cord) or in the peripheral nervous system (the nerves sending messages to and from the brain and spinal cord) • Epilepsy: A disorder of the brain in which the brain cells send off an abnormal electrical signal, causing seizures involving jerky, uncontrolled movements and sometimes a loss of consciousness • Stroke: Decreased blood supply to the brain caused by a clot (thrombosis) or haemorrhage (bleed) • Dementia: A problem with the brain caused by destruction of brain cells, making it difficult to remember, learn and communicate. Also associated with mood and personality changes • Alzheimer’s disease: An irreversible brain disease that slowly destroys memory and thinking cells. It is a progressive disease that leads to the inability to carry out even the simplest of tasks. Physical activity, social engagement, a nutritious diet and mentally stimulating activities can all help to keep the brain healthy • Parkinson’s disease: A progressive disease that causes problems in brain nerve cells that control movement. Results in tremors and shaking, especially when resting. Affected people also have nightmares, extra saliva, depression, and difficulty walking and performing daily tasks, such as buttoning a shirt • Multiple sclerosis: An autoimmune disease affecting the nervous system. Some nerves have a protective sheath around them called myelin. Destruction of this myelin causes interference and problems with the conduction of nerve signals, resulting in an array of problems such as vision problems, memory issues, fatigue, muscle weakness, dizziness, tremors, trouble with coordination and balance and loss of bowel or bladder control

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING



WORKOUT 1.4

Body system

Body-system disorders

Circulatory system

• Heart disease: An umbrella term for many different diseases affecting the heart. Examples include: a coronary artery disease, where the arteries supplying blood to the cardiac muscle and surrounding tissue are affected (damaged or blocked) b cardiomyopathy, or heart muscle disease, in which there is deterioration of the function of the myocardium (heart muscle), placing the client at risk of arrhythmia or even sudden cardiac death c cardiovascular disease, which includes any of a number of special diseases that affect the heart itself or the blood vessel system, especially the veins and arteries taking blood to and from the heart. Diabetes mellitus and hypertension are very closely related to cardiovascular disease. Atherosclerosis is a type of cardiovascular disease • Peripheral vascular disease: A disease of the large arteries of the arms and legs caused by narrowing or obstruction of the arteries. Sufferers tend to experience claudication – pain, weakness and cramping in muscles during walking – as a result of decreased muscle blood flow

Respiratory system

• Diseases of the lungs, the pleural cavity (the body cavity surrounding the lungs) and the respiratory airways (e.g. bronchial tubes, trachea and upper respiratory tract): – Chronic obstructive pulmonary disease (COPD): A term used for two conditions called chronic bronchitis and emphysema – Asthma: A fairly common inflammatory condition causing airway obstruction and bronchospasm. Signs and symptoms include wheezing, coughing, chest tightness and shortness of breath

Digestive system

• Coeliac disease: Gluten is a protein found in food such as wheat, rye, barley and oats. This disease causes an inappropriate immune reaction to gluten, resulting in inflammation and damage to the small intestine • Crohn’s disease: A type of inflammatory bowel disease affecting any part of the gastrointestinal tract from the mouth to the anus

1 2 3 4 5

Describe how the cardiovascular system changes when a person begins aerobic exercise. Research which body systems would change when performing resistance training. What is the largest organ of the human body? Which organs are involved with the nervous system, and what is the nervous system’s function? Choose four of the disorders listed in Table 1.6 and consider the relevant potential contraindications and precautions, then answer the following questions for each disorder: a What lifestyle changes might you suggest to this client? b What referral plan would you implement?

1.3  MUSCULOSKELETAL SYSTEM The skeletal system Axial skeleton Consists of the skull and facial bone, the sternum, the ribs and the vertebral column Appendicular skeleton Consists of the pectoral girdle and the arms (the scapula, clavicle, humerus, radius, ulna, carpal, metacarpals and phalanges), and the pelvic girdle and the legs (the ilium, ischium, pubis, femur, patella, tibia, fibula, tarsals, metatarsals and phalanges)

There are 226 bones in the adult body, connected by a variety of joints. Muscles produce force that causes movement to occur at the joints (see Figure 1.11). The skeleton can be divided into the axial skeleton and appendicular skeleton. The axial skeleton is in the core of the body and consists of the skull and facial bone, the sternum, the ribs and the vertebral column. The appendicular skeleton relates to the peripheral part of the body and consists of: • the pectoral girdle and the arm – the scapula, clavicle, humerus, radius, ulna, carpals, metacarpals and phalanges • the pelvic girdle and the legs – the ilium, ischium, pubis, femur, patella, tibia, fibula, tarsals, metatarsals and phalanges.

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CHAPTER 1 Anatomy and physiology

Cranium

Clavicle Scapula

Ribs

Mandible Cervical vertebrae (7 in total)

Thoracic vertebrae (12 in total, at the back of the rib cage) Sternum

Humerus Lumbar vertebrae (5 in total) IIium Radius

Sacral vertebrae (5 fused bones)

Ulna

Carpals Metacarpals

Phalanges

Coccyx (4 fused bones) Ischium

Pubis

Femur Patella

Tibia

Fibula Tarsals Talus Metatarsals Phalanges

Figure 1.11 The skeleton

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Functions of the skeletal system Joint Where two bones meet

The skeleton is a collection of different-shaped bones that join together to give humans their shape. Two bones meet to make a joint. The skeleton supports the soft tissues of the body for maintenance of the body’s form and posture. For example, the legs support the body trunk. Bones of the skeletal system provide an attachment point for skeletal muscles so that movement can occur. Movements include throwing a ball or vital movements such as breathing. The functions of bone include: • Protection: The strong structure of the skeleton can protect vital organs. For example, the skull protects the brain. • Movement: The skeletal system is the structure that muscles attach to. When contracted, it provides movement. It provides the structure and posture of our body. • Storage of minerals: This includes calcium and phosphorus, which are stored in the bone. Calcium is vital for muscle contraction and the transmission of nervous system messages. If the body is lacking calcium, the calcium will be removed from the bones and enter the blood. • Haematopoiesis: This is the production of blood cells. It occurs in the marrow cavities of some bones.

Gross anatomy of bone Diaphysis The main and middle portion of a long bone Epiphysis The end of a long bone

Bones come in many different shapes and sizes, which can be categorised into several different types: long bones, flat bones, irregular bones and short bones. (See Table 1.7 and Figures 1.11 and 1.12.) Short, irregular and flat bones do not have a diaphysis (shaft of the bone) or epiphysis (end of the bone); instead, basically, compact bone surrounds a layer of spongy bone.

Table 1.7 Types of bones Long bones

Include the humerus, radius, ulna, femur, tibia and fibula. Consist mainly of compact bone with spongy bone at the ends. The shaft of long bones is constructed of a thick collar of compact bone on the outside and a cavity of yellow bone marrow, which contains fat, on the inside. The shaft is called the diaphysis. The end of a long bone is made of compact bone on the outside and spongy bone on the inside. These ends are called the epiphyses. The end of a long bone is covered with a thin layer of articular (hyaline) cartilage, which is smooth and glassy in appearance

Flat bones

Include the sternum, the ribs and bones of the skull. They are protective bones for soft organs, such as the lungs

Short bones

Roughly cube-like bones found in the ankle (e.g. the tarsal bones) and in the wrist (e.g. the carpal bones). They provide stability and strength

Irregular bones

Include the vertebrae and pelvis, which have various functions: the vertebrae help protect the spinal cord and the pelvis helps protect the pelvic organs, such as the bladder

Bone cells (osteocytes)

Ground reaction force (GRF) A force exerted by the ground on any body that comes into in contact with it

Evidence suggests that good physical-activity habits in childhood lead to long-lasting bone health and benefits into adulthood. A German anatomist, Julian Wolf, identified that if stress is placed on healthy bones the bone will adapt to cope with the stress (Marieb, 2014). Therefore, physical activity that tends to apply mechanical force to bone and is dynamic in nature tends to have the most beneficial effects on building bone strength. Note that the ground reaction forces (GRFs) that develop with different exercises will vary, and it appears that the exercises that generate the highest GRFs have the most beneficial impact on bone mineralisation. Peak bone mass is thought to occur by about the end of the third decade of life, and it is important to stress this to your clients, because the early-adult years might be the final chance to maximise peak bone mass.

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CHAPTER 1 Anatomy and physiology

Long bone (e.g. humerus of arm)

Flat bone (e.g. cranium)

Short bones (e.g. carpals of wrist)

Irregular bone (e.g. vertebra)

Figure 1.12 Bone shapes The GRF produced during some different activities is as follows: •  Jumping can produce a GRF up to 6–8 times a person’s body weight. •  Some gymnastic activities produce a GRF up to 10–15 times a person’s body weight. • Walking or running tends to produce a lower GRF of around 1–2 times a person’s body weight. No ideal program is available, but current research suggests the following for facilitating bone mineral development in children and adolescents: • Mode: Impact activities such as gymnastics, moderate-intensity resistance training, plyometrics and jumping • Intensity: Bone-loading forces should be high, but for safety reasons the loads should be less than 60 per cent of one repetition maximum (see Chapter 5 for a more detailed explanation of repetition maximum) • Frequency: At least three times per week • Duration: A total of 10–20 minutes per day. In adulthood, the goal of physical activity should be to maintain bone mass. Whether physical activity can increase bone mass in adults is yet to be determined; however, it is unlikely it can. Any increases in bone mass in adults have been linked to relatively high-intensity, weight-bearing endurance or resistance exercises. Your clients should be made aware that the reverse will also occur when exercise is stopped, after which bone mass is likely to decrease. There is an age-related decline in bone mineral density. This can be slowed down somewhat by physical activity – specifically, weight-bearing activities – even if it is not vigorous. In women, there is a post-menopausal loss of bone mineral density, and even physical activity does not seem to stop this. Even post-menopausal clients who participate in physical activity may still need some pharmacological intervention. According to the American College of Sports Medicine, adults should try to maintain their bone mineral density, or at least help to slow down the age-related decline in bone mineral density, by participating in physical activity that follows these guidelines: • Mode: Weight-bearing activities such as tennis, stair climbing or jogging at least intermittently while walking; jumping activities, such as volleyball, and resistance exercise • Frequency: Weight-bearing endurance exercise at least 3–5 times per week and resistance exercise at least 2–3 times per week • Duration: 30–60 minutes of a combination of weight-bearing endurance activities involving jumping and resistance exercise that targets all major muscle groups (Metcalfe et al., 2001). Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

TIP

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TIP

Epiphyseal plate A hyaline cartilage section at each end of long bones in children and adolescents Growth plate The layman’s term for the epiphyseal plate

PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

Bone mineral density tends to be highest in athletes of high-intensity sports, such as gymnastics, weightlifting and bodybuilding. It is lowest in athletes from non-weight-bearing activities, such as swimming and cycling. Keep in mind that any form of bed rest or immobilisation will result in rapid and substantial decreases in bone mineral density. Even the frail elderly should try to remain as physically active as their health allows, including some weight-bearing endurance exercise and resistance exercise to try to preserve bone mass as well as exercises aimed at improving balance and reducing the risk of falls. Overall, physical activity appears to help maximise bone mass if it is performed during childhood and the early-adult years. With physical activity, bone mass can be maintained through to the fifth decade, in some instances.

Growth and development of bone tissue The site of bone growth in children is at the hyaline cartilage in the epiphyseal plate. This plate is sometimes referred to as the growth plate. During infancy and youth, long bones can grow lengthways by a process called interstitial growth (see Figure 1.13).

Epiphysis

Articular cartilage

Epiphyseal line

Spongy bone Compact bone Diaphysis Medullary (yellow marrow) cavity

Epiphysis

Figure 1.13 The structure of a long bone Interstitial growth The process of bone growing in length Epiphyseal line The line at each end of a long bone where the epiphyseal plate used to be, once a person has stopped growing Appositional growth Growth in the thickness of a bone

Interstitial growth occurs when the cells on the epiphyseal side of the growth plate divide quickly and push the plate away from the diaphysis. It is important that this area is not injured or placed under too much strain during childhood to ensure that the child’s growth is not hindered. This is one of the reasons why heavy weight training has not been recommended for children in the past. However, this theory is being challenged, with some researchers suggesting that resistance training is necessary for bone strength in the younger years. This is still in need of further research. Some time between the ages of about 16 and 25, the hyaline cartilage at the epiphyseal plate is replaced by bone, leaving only the epiphyseal line. This event is called epiphyseal plate closure. Bones can also grow in thickness by a process called appositional growth, which occurs because there is an unequal balance between creation and destruction on the bone-collar surface. Adult bones can continue to thicken throughout life. Appositional growth can be particularly affected by the amount and type of exercise you do. Weight-bearing exercise, such as running and weight training, can have a positive effect on bone growth and strength. Lack of exercise can cause bones to weaken.

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CHAPTER 1 Anatomy and physiology

Joints As has already been explained, a joint is the site where two bones meet, and movement is achieved through the muscles surrounding that joint. The bony landmarks, such as tuberosities, trochanters and tubercles, indicate areas of muscle origin and insertions. Understanding where muscles start and finish in the body will help you when you are learning muscle actions and functions. Figure 1.17 (later in this section) illustrates the location of major joints and bony landmarks in the body.

Joint classification Joints can be classified according to their structure. There are many different ways to classify them (see Figure 1.14). (a) Fibrous joint Fibrous connective tissue

(b) Synovial joint Articular capsule

Articular (hyaline) cartilage

Scapula

Humerus

(c) Cartilaginous joint

Pubis

Fibrocartilage

Figure 1.14 Types of joints

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Fibrous joints Bones connected by dense connective tissue (e.g. the skull joints) Synovial joint A joint that contains a cavity filled with a fluid called synovial fluid Cartilaginous joints Joints connected entirely by hyaline or fibrocartilage

Fibrous joints join bones and do not have a cavity between the bones. Some fibrous joints are slightly moveable joints, while some, such as the skull, have no movement. These joints play a huge role in protecting the brain, particularly in sports such as boxing where the skull can suffer direct blows. Synovial joints have a cavity containing fluid. Synovial joints allow movement to occur – for example, the hip and shoulder joints. Synovial fluid provides lubrication to the joint. However, sometimes the extra movement allowed by synovial joints places them at greater risk of injury and overuse. Cartilaginous joints are connected by cartilage, either hyaline or fibro, and do not have a joint cavity. The joint between the ribs and the sternum is an example of a cartilaginous joint where there is hyaline cartilage between the bones. During exercise, when breathing is deeper, the chest cavity expands, and this joint allows for that movement.

Synovial joints Synovial joints will be the joints of most interest when you are prescribing exercise. These joints have certain distinguishing features (see Figure 1.15 and Figure 1.16). Acromion of scapula Ligament Bursa Ligament Joint cavity containing synovial fluid

Articular (hyaline) cartilage

Tendon sheath

Synovial membrane Tendon of biceps muscle Fibrous articular capsule Humerus

Figure 1.15 Components of a synovial joint Articular cartilage Connective tissue found at the ends of long bones. It is made of hyaline cartilage and provides a smooth joint surface to help minimise friction Joint cavity The space between two bones where they meet Articular capsule A covering of the joint cavity Synovial membrane The internal lining of a joint

The articular cartilage provides a spongy cushion for the joint. This helps to prevent the joint from being crushed. As noted earlier, osteoarthritis is a condition where there is a deterioration of the articular cartilage that causes pain and immobility. It is common for osteoarthritis to affect weight-bearing joints such as the hip and knee, and in severe cases joint replacement may be necessary. Rhythmical exercises, such as ballistic movements, that allow the joints to warm up are often the best-tolerated types of exercise for people suffering osteoarthritis. The joint cavity is the space between the bones that make up the joint. In fact, it is more of a ‘potential’ space than a real one, because it is filled with synovial fluid. The fluid remains within the joint unless the joint suffers an injury that allows the fluid to seep out. The articular capsule covers the joint cavity. It is double-layered, with an external layer that is a tough, flexible, fibrous capsule similar to the gel capsule of some medications. The synovial membrane is composed of loose connective tissue. This membrane lines the fibrous capsule internally and lines all internal surfaces of the joint other than the hyaline cartilage.

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CHAPTER 1 Anatomy and physiology Synovial fluid is found in small amounts within the joint capsule. It is largely derived through filtration from blood flowing through the capillaries in the synovial membrane. It has a viscous, eggwhite consistency that becomes less viscous as it warms – for example, during exercise. The synovial fluid functions to decrease friction within the joint. During normal movements the synovial fluid is squeezed in and out of the cartilages by a process called weeping. The menisci (plural for meniscus) are pads of fibrocartilage located between articulating surfaces of different-shaped bones. They absorb shock and help stabilise the joint by providing a tighter fit. Two menisci can be found within each knee joint: a lateral and a medial meniscus. Bursae (plural for bursa) are fluid-filled sacs located between structures that move. They reduce friction and cushion the movement.

Gross anatomy of synovial joints Synovial joints can vary in appearance and ability to allow movement (see Figures 1.16 and 1.17). (f) Ball-and-socket joint (hip joint)

(a) Pivot joint (between C1 and C2 vertebrae)

(b) Hinge joint (elbow) (b) Condyloid joint (between radius and carpal bones of wrist)

(c) Saddle joint (between trapezium carpal bone and first metacarpal bone)

(b) Plane joint (between tarsal bones)

Figure 1.16 Types of synovial joints

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Synovial fluid Found in small amounts within the joint capsule Menisci Pads of fibrocartilage between bones at a joint (plural for meniscus) Bursae Sacs of fluid between structures to reduce friction (plural for bursa)

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

Posterior Mastoid process of temporal bone C7 spinous process Spine of scapula Vertebral border of scapula

Acromion process of scapula Axillary border of scapula

Superior angle of scapula

Inferior angle of scapula

Olecranon process of ulna

Lateral epicondyle of humerus

Posterior superior iliac spine (PSIS)

Medial epicondyle of humerus

Greater trochanter of femur

Posterior border of ulna Carpals Metacarpals

Styloid process of radius

Phalanges Coccyx

Styloid process of ulna

Ischial tuberosity Iliac crest Sacrum

Lateral epicondyle of femur

Medial epicondyle of femur

Head of the fibula

Medial malleolus Lateral malleolus

Calcaneus Anterior

Zygomatic bone

Coracoid process of scapula

Clavicle Sternal notch

Sternum Ribs Head of radius

Xiphoid process Medial epicondyle of humerus Lateral epicondyle of humerus

Iliac crest Anterior superior iliac spine Greater trochanter of femur

Pisiform Pubis symphysis Patella

Medial epicondyle of femur

Lateral epicondyle of femur Head of fibula Tuberosity of tibia Anterior shaft of tibia

Medial malleolus

Lateral malleolus

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CHAPTER 1 Anatomy and physiology Hinge joints consist of a convex projection of one bone that fits with a cylindrical groove on the other. They allow flexion and extension movements only. The elbow and knee are examples of hinge joints. Gliding/plane joints allow slipping movements when two flat surfaces glide across each other. The carpal bones in the wrist are an example of this. Pivot joints are described by a rounded end of a bone that articulates with a ring of another bone. The atlas and axis bone in the top of the vertebrae in the neck is an example of a pivot joint that allows the head to pivot. Saddle joints have both concave- and convex-shaped bones at the joint (similar to a saddle on a horse). An example is the carpal and metacarpal bones in the thumb and wrist. In condyloid joints, the ends of the joins are both concave and allow the bones to move from side to side and backwards and forwards, but not to rotate. The joint between the hand and the fingers is a good example of a condyloid joint. In ball-and-socket joints, the end of one bone has a rounded head and the end of another has a socket-like feature. The hip and shoulder are ball-and-socket joints. This type of joint allows for movement in many different directions and is the most freely moving synovial joint. An example is a baseball pitcher, where the shoulder joint moves through many different directions when pitching the ball. Review Workout 1.5 to test your knowledge of joints. 1 Summarise the functions of each part of a synovial joint. Research how each structure may be positively or negatively affected by weight-bearing cardiovascular exercise and resistance exercise. Use the table below to record your answers: Part of synovial joint Function

Effect of weight-bearing cardiovascular exercise

Hinge joints Allow flexion and extension movements only

Saddle joints A combination of a convex and concave surface allowing for a wide range of movement Ball-and-socket joints Allow movements in many directions

WORKOUT 1.5

Effect of resistance exercise

Articular capsule Joint cavity Articular cartilage Synovial membrane Synovial fluid Menisci in the knee Bursae Ligaments Tendons

2 Summarise the factors that affect bone strength and development. Use the table below to record your answers. The first row has been completed for you. Factor affecting bone strength

Positive or negative effect on bone strength

Calcium intake

Increases bone strength

Weight-bearing exercise, such as running Sedentary lifestyle Smoking Extreme low weight Swimming Low vitamin-D levels



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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING



COMPUTER SKILLS

Homeostasis The process by which the human body stays in a state of equilibrium

Nutrients Substances consumed to provide energy and growth or to promote energy production and growth

3 Name the functions of bone. 4 Name the type of synovial joint in each of the following: a Rotation at the elbow joint b Wrist joint c Knee joint d Shoulder joint. 5 List one example of a: a hinge joint b ball-and-socket joint c saddle joint d gliding joint. 6 What is the name given to each of the following? a The shaft of a long bone b The ends of long bones. 7 What types of cells are made in bone? 8 What function does articular cartilage provide in joints? What is the name of the condition in which articular cartilage deteriorates? 9 Challenge yourself by playing Skeletal System game at the following link: https://www.purposegames.com/game/1009.

Bone remodelling/disorders of the skeletal system Bone is not a dormant structure in the human body – it is continuously changing. In fact, approximately 5–7 per cent of bone mass is recycled every week. Middle-aged and older adults rely greatly on having a strong bone structure and adequate peak bone mass developed from their younger years. Humans need to increase their bone mass to as high a level as genetically possible before reaching peak bone mass at around age 35. Many things can cause a bone to become stronger or weaker, which represents a change in the bone’s homeostasis. Homeostasis is a state of body equilibrium and the maintenance of a stable internal environment of the body. A fracture or break in bones is a common disorder of bone homeostasis. Alcohol consumption may increase bone loss. Heavy smoking is also associated with increased risk of osteoporosis, bone fractures and lower bone density, as well as fewer teeth. Menopause causes a decline in the hormone oestrogen, which has an impact on bone strength, although the exact details of why this occurs are not fully understood. Low body-fat levels can inhibit the absorption of fat-soluble vitamins such as vitamin A, which can also cause a decline in bone strength. Bone requires many nutrients for health, including calcium, protein, phosphorus, zinc, manganese, copper and vitamins A, C, D and K. As noted earlier, if you do not get enough calcium from your food intake, your body will remove calcium from your bones. Vitamin D plays a major role in calcium absorption. Your body is capable of producing vitamin D from adequate doses of sunlight. Keep in mind that absorption of any nutrient will vary greatly among people. Unfortunately, cooking techniques, pollution and chemicals used in the growing process often destroy nutrients found in food.

The muscular system When we think of the muscular system, we tend to think about movement and the muscles we can see. Muscles also help with maintaining posture and stabilising joints so that the exercise can be performed correctly. For example, when performing a standing calf raise, many muscles throughout the body are working to help keep the body upright while the gastrocnemius (calf muscle) is contracting to move the body through the exercise. Movements performed by the skeletal muscle are also partly responsible for the generation of heat within the body. (See Figures 1.18 and 1.19 for anterior and posterior views of muscles, and Figures 1.20, 1.21 and 1.22 for types of muscles in the body. See Table 1.8 for a list of muscles and their major actions.) We also rely on specialised muscle to contract our heart and organs, even when we are asleep.

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CHAPTER 1 Anatomy and physiology

Frontalis Temporalis Masseter Platysma

Orbicularis oculi Zygomaticus Orbicularis oris Sternocleidomastoid

Deltoid Pectoralis major

Pectoralis minor

Triceps brachii Serratus anterior Biceps brachii

External intercostals Rectus abdominis

Brachialis

External oblique

Brachioradialis

Internal oblique Transversus abdominis

Flexor carpi radialis IIiopsoas

Tensor fascia lata (TFL)

IIiotibial band (ITB) Sartorius Rectus femoris Quadriceps group

Adductor muscle

Vastus lateralis Vastus medialis Vastus intermedius (deep) Fibularis longus

Extensor digitorum longus

Tibialis anterior

Figure 1.18 The muscular system – anterior view

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Table 1.8 Muscle actions Muscle

Action

Biceps

Flexion and supination of forearm

Triceps

Extension of forearm

Hamstrings

Extension of hip and flexion of knee

Sartorius

Flexion, abduction and lateral rotation of hip and flexion of knee

Quadriceps femoris

Extension of knee (but rectus femoris also helps iliopsoas with flexion of hip)

Deltoids

Anterior: Flexion and medial rotation of shoulder Middle: Abduction of shoulder Posterior: Extension and lateral rotation of shoulder

Wrist extensors

Extension of wrist

Wrist flexors

Flexion of wrist

Gastrocnemius

Plantarflexion of ankle and flexion of knee

Soleus

Plantarflexion of ankle

Tibialis anterior

Dorsiflexion of ankle and inversion of foot

Gluteus maximus

Extension of hip; assists in lateral rotation of hip and raising the trunk from a flexed position

Iliopsoas

Flexion of hip

Latissimus dorsi

Extension, adduction and medial rotation of the shoulder

Pectoralis major

Adduction and medial rotation of humerus

Trapezius

Elevation, retraction and rotation of scapula: Superior fibres: Elevation of scapula Middle: Retraction of scapula Inferior: Depression of scapula

Serratus anterior

Protraction of scapula

Rhomboids

Retraction of scapula

External oblique

Flexion and rotation of trunk to the opposite side

Internal oblique

Flexion and rotation of trunk to the same side

Transversus abdominis

Compression and support of abdominal viscera

Rectus abdominis

Flexion of trunk and compression of abdominal viscera

Erector spinae

Extend vertebral column and head when acting bilaterally; control back flexion by gradually lengthening their fibres; laterally bend the vertebral column when acting unilaterally

Muscles are sometimes referred to as global or local muscles. Global muscles, including the rectus abdominis and external oblique (see Figure 1.19), do not attach directly to the trunk or spine, yet they are able to produce large torques on the trunk and spine. Local muscles lie deep within the body and have attachments to the spine. The transversus abdominis (see Figure 1.19) is an example of a local muscle.

Types of muscle Cardiac muscle Found in the heart and is under involuntary control

There are three types of muscle tissue – namely, cardiac, smooth and skeletal muscle, which are shown in Figure 1.20 (see also Table 1.9). Cardiac muscle (myocardium) is found in the heart and is under involuntary control, meaning it works without your thinking about it.

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CHAPTER 1 Anatomy and physiology

Rhomboids (deep to trapezius)

Trapezius

Deltoid

Triceps brachii

Latissimus dorsi Extensor carpi radialis longus Flexor carpi ulnaris

External oblique

Extensor carpi ulnaris Extensor digitorum

Gluteus medius Gluteus maximus

Adductor muscle Iliotibial band (ITB) Biceps femoris Semitendinosus

Hamstring group

Semimembranosus

Gastrocnemius

Soleus

Fibularis longus

Achilles tendon

Figure 1.19 The muscular system – posterior view

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Cardiac muscle

Skeketal muscle

Smooth muscle

Figure 1.20 Types of muscle tissue Figure from Beck, Theory and Practice of Therapeutic Massage, 5th edition. 2011 Cengage Learning. Smooth muscle Lines some organs, such as the stomach and arteries, and works without conscious thought Skeletal muscle One of three major muscle types, the others being cardiac muscle and smooth muscle. It is a form of striated muscle tissue that is under the ‘voluntary’ control of the somatic nervous system. Most skeletal muscles are attached to bones by bundles of collagen fibres known as tendons

Smooth muscle lines organs such as arteries in the cardiovascular system, and works without conscious thought. This muscle can contract and relax to assist with movement of blood throughout the body, particularly during exercise. Hardened arteries caused by an unhealthy diet (e.g. one full of saturated fat) or smoking can make this process more difficult. Skeletal muscles are attached to bones and are responsible for movement of the skeleton (see Figure 1.21). Skeletal muscles are under voluntary control.

Table 1.9 Comparison of muscle types Cardiac muscle

Smooth muscle

Skeletal muscle

Striated in appearance

Yes

No

Yes

Fatigue resistant

Yes

Yes

No

Voluntary

No

No

Yes

Speed of contraction

Slow to fast

Very slow

Fast

Rhythmical contraction

Yes

Yes, in some

No

Location

In the heart

Mostly in organs and blood vessels

Attached to bones

Extensibility and elastic

No

No

Yes

Muscle cells (muscle fibres) and exercise Hypertrophy Occurs when an organ or tissue increases in size because the cells increase in size Hyperplasia Occurs when an organ or tissue increases in size because the cells increase in number

Muscle cells are also called muscle fibres. Exercise has a large effect on muscle fibres. For a start, it is quite obvious that muscles can get stronger and increase in size – you only have to set foot into a fitness facility to see that. But how does this occur? Do muscle cells increase in size (hypertrophy) or increase in number (hyperplasia)? The possible individual increase in muscle bulk is likely to be genetically determined, and there is currently no evidence to support hyperplasia occurring in humans. However, there are stages during which hyperplasia occurs in humans, specifically in growth periods such as adolescence. Current research instead suggests that any enlargement of existing muscle fibres that occurs with physical activity (mainly resistance training) is due to enlargement of existing muscle fibres, rather than the production of new muscle fibres. Placing varying forces on the body’s muscles will lead to an increase in muscle size, with measurable changes occurring within about three weeks of training, independent of gender and age. Progressive overload training increases muscle fibre size with subsequent muscle growth. High, intense levels of resistance training may impede relative aerobic capacity. This is due to muscle fibres being relatively better at resistance training than aerobic exercise. Resistance training will increase the total contractile proteins and energy-generating compounds relevant to resistance training, but not to aerobic training.

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CHAPTER 1 Anatomy and physiology

Tendon Skeletal muscle

Fascia

Epimysium Muscle fascicle Perimysium

Muscle fascicle

Nerve

Muscle fibre

Blood vessels

Periosteum covering the bone

Endomysium

Muscle cell nuclei

Sarcolemma Sarcoplasm Mitochondria

Transverse tubule Sarcoplasmic reticulum Myosin Myofibrils

Myofilaments

Striations

Sarcomere

Actin

Figure 1.21 Structure of skeletal muscle Figure from Beck, Theory and Practice of Therapeutic Massage, 5th edition. 2011 Cengage Learning.

Strength gains in muscle fibres are not equal along a muscle from its origin to its insertion points on bones. Muscle strength is specific to different places along a muscle length. Men and women can both increase their muscle strength. However, any gender-related differences you do see would be a result of differences in hormonal responses to exercise due to men producing more testosterone (related to muscle growth) and less cortisol (related to weight gain and obesity). There is also a positive relationship between muscle strength and bone mineral density. Resistance training can place a positive stress on bones and promote bone health. Cessation of resistance training will result in a loss of strength. Even two weeks off training can result in significant reductions in strength, most likely due to reversal of the neuromuscular and hormonal adaptations that training produced.

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Semispinalis capitis muscle Splenius capitis muscle Trapezius muscle Levator scapulae muscle Rhomboideus minor muscle Supraspinatus muscle Rhomboideus major muscle Spine of scapula Teres minor muscle Infraspinatus muscle

Deltoid muscle

Teres major muscle Infraspinatus fascia Long head of triceps brachii muscle Triangle of auscultation

Latissimus dorsi muscle

a

Psoas major

b

Piriformis

lliacus Tensor fasciae latae

Gluteus medius

Adductor brevis

Gluteus maximus

Pectineus Adductor longus Gracilis

Adductor magnus lliotibial tract

lliotibial tract

c

d

Figure 1.22 Types of muscles: (a) Upper-back muscles (superficial); (b) upper-back muscles (deep) – top layer removed; (c) deep hip muscles (anterior view); (d) deep hip muscles (posterior view)

Delayed onset muscle soreness (DOMS) Muscle soreness and stiffness are typical after unaccustomed exercise or exercise after a period of time off. More severe, residual muscle stiffness and soreness is called delayed onset muscle soreness (DOMS) and can last three to four days. Eccentric-type (i.e. lengthening) exercise tends to produce the greatest DOMS, especially in older populations. Running downhill on even a slight slope (e.g. 10 degrees) for extended periods (e.g. 30 minutes) has been shown to produce considerable DOMS. Plyometric training is another form of exercise that is commonly associated with DOMS due to the excessive loading through explosive and jumping loads on muscle.

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CHAPTER 1 Anatomy and physiology

• • • • •

DOMS is thought to be caused by one or more of the following factors: acute inflammation muscle spasms fluid retention in surrounding tissues minute tears in the muscle tissue or connective tissues changes in the way the muscle cell regulates calcium levels (calcium is very important for muscle contractions, and is discussed further in this chapter’s section on the cross-bridge cycle). DOMS is discussed in more detail in Chapter 5.

The role of individual muscles during exercise Muscles can be classified into four functional groups: 1 Prime movers (or agonists) are the muscles responsible for the desired action. 2 Antagonists are the muscles that oppose or reverse the movement. They can also contract during the movement to stop or slow down the desired movement. 3 Synergists can assist the movement by limiting undesired movements or helping in the contraction desired. 4 Fixators stabilise the bone at the origin of the prime mover to ensure that all of the contraction of the muscle is directed to the bone into which the muscle is inserted. Let’s look at an example of these muscles in action. During a biceps curl in the gym, the following muscles are identified: • Agonist – biceps brachii • Antagonist – triceps brachii • Synergist – brachioradialis and brachialis  • Fixator – rotator cuff muscles Let’s now look at this second function in slightly more detail, because it deserves further explanation. When a muscle crosses two or more joins, the contraction acts across both joints but movement can occur at one or both joints. Why is this? An example will explain it. In a standing calf raise, the quadriceps will stabilise the knee so that the knee joint remains straight during the contraction of the soleus and gastrocnemius to produce the plantar flexion at the ankle joint.

Muscle attachments and actions In order for movement to occur, muscles contract, causing tension and causing the bones to move across the joint. The muscles are attached to bones by tendons, and these attachments are known as the origin (muscle attached to the bone that does not move during exercise). The insertion of the muscle is the moving end. For example, the biceps brachii has two origins (because it has two muscle bellies) in the shoulder area and its insertion point is via a tendon on the radius (bone in the forearm). Major muscle actions were listed earlier in Table 1.8.

Muscles for exercise Many people think of starting to exercise without proper instruction and guidance. Fitness instructors are trained to know the function of muscles and try to ensure that muscle imbalances (e.g. having stronger quadriceps compared to hamstrings) are accommodated through careful exercise prescription. Muscle imbalances are common and can predispose a person to injury or postural abnormalities. Sometimes muscle imbalances are hard to avoid. For example, we use the iliopsoas (hip flexor) muscle a lot during everyday life. Walking requires the hip to flex, which is caused by contraction of the iliopsoas. In addition, we tend to sit a lot, causing this muscle to be in a shortened position, so it is not uncommon for the iliopsoas to be quite tight while the gluteal (buttocks) muscles weaken. Tight iliopsoas muscles can also place strain on the lumbar spine. An appropriately tailored exercise plan needs to take these imbalances into consideration and incorporate strategies to minimise the risk of injury. Group fitness sessions can often involve lots of jumping, running and different aerobic moves such as grapevines. A well-trained instructor will know that the gastrocnemius and soleus muscles (see Figure 1.23) will be well conditioned from such moves due to the amount of plantar-flexion movements involved. Hence, gastrocnemius and soleus stretching will be of particular interest to the group exercise instructor. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

Prime mover The muscle most responsible for a movement Agonist The muscle responsible for a movement Antagonist The muscle opposing a movement Synergist A muscle assisting the prime mover Fixator A muscle stabilising the body so the main movement can occur

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Gastrocnemius muscle

Soleus muscles

Figure 1.23 Gastrocnemius and soleus muscles

Which muscles are working during exercises?

Isotonic contractions Occur when a muscle produces force while changing length. There are two phases in this type of contraction Concentric The muscle tension that is created while shortening the muscle Eccentric The muscle tension that is created while lengthening the muscle Isometric contractions Occur when a muscle is producing force without changing length Isokinetic contractions Occur when the muscle produces force and there is movement at a fixed angular velocity

As a fitness instructor, it is essential to have a good understanding of the muscles and the actions they perform when prescribing exercise for clients. This will help you to understand the strength and flexibility requirements for your clients’ needs and to program exercise to reach the maximum benefits. You also need to understand the structure and function of each muscle and any underlying risks for injury. For example, the quadriceps are inherently stronger than the hamstrings because the orientation of the quadriceps muscle fibres favour strength. On the other hand, the orientation of the hamstring muscle fibres favours speed of contraction. This difference between these two opposing muscle groups often predisposes the hamstrings to muscle tears. Therefore, when you are prescribing exercise you need to be aware of how the muscles are working (e.g. as an agonist, antagonist, synergist or fixator) and to have an understanding of the client’s strength and flexibility capabilities.

Types of muscle contractions There are different types of contractions that occur during exercise. • Isotonic contractions (meaning the tension remains the same while the length changes) occur when a muscle produces tension or force while lengthening and shortening. There are two phases to an isotonic contraction: concentric and eccentric. Concentric contractions occur when a muscle shortens during contraction – for example, in the upward phase of a biceps curl. Eccentric contractions occur when the muscle lengthens – for example, in the downward phase of a biceps curl. • Isometric contractions (meaning the length of the muscle does not change during tension) occur when a muscle produces tension without changing length or joint angle. Performing the plank is an example of an isometric contraction. • Isokinetic contractions occur when the muscle works through a set range of motion at a constant angular speed. The equipment used for isokinetic training, such as hydraulic machines, can adapt the resistance throughout the movement so that the muscle is worked maximally at all joint angles. Examples of these pieces of equipment can be found in some fitness facilities. Review Workout 1.6 to test your knowledge of muscle contractions.

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CHAPTER 1 Anatomy and physiology

Functional training of muscles The use of machines in fitness facilities has had a long history over the past few decades; however, there appears to be an industry-wide shift towards performing as much ‘functional’ training as possible. The reason behind this is that functional training will be more specific to the needs of the client, whether it relates to a specific sport or activities of daily living. The focus of functional training is to perform exercise in a manner that is specific to the needs of that client’s activities of daily living and/or their chosen sport.

TIP

Functional training can include performing dynamic exercises in an upright position to mimic the forces (namely, gravity and GRF) that a person faces daily. As mentioned earlier in the chapter, if you are training an older man who is struggling with getting up from his couch at home, the ideal training would be to practise actually ‘getting up from the couch’. Functional training for this client could include assisted sit-to-stands and squats, because similar muscles are used; however, whether the speed and weight involved are the same as actually performing the task of getting up from the couch depends on the exercise prescription from the fitness instructor. In a fitness facility, the prescribing of squats could play a very useful role in helping the client achieve his goal. Further research in the area of functional-training exercise prescription is still required. 1 Match the following examples of exercise with the type of muscle tension produced. An example has been provided to assist you. Exercise examples

Type of muscle tension

Pushing against a wall

Isotonic

Performing abdominal crunches

Isometric

Lunges

Isometric

Performing the plank

Isometric

Holding a shopping bag

Isometric

Performing leg extensions

Isotonic

WORKOUT 1.6

2 What does DOMS refer to, and when is it likely to occur? 3 Suppose you have as a client a tennis player who needs to increase muscular endurance and strength to perform better in longer matches. Research the functional movements involved in tennis and devise five resistance training exercises that would be suitable for the client. Consider what type of exercises you will prescribe – will they be isolation, compound, isotonic, isometric, isokinetic and/or functional? 4 Challenge yourself with the Muscles of the Body game; see https://www.purposegames.com/ game/716d7f0d15.

How muscle works – the cross-bridge cycle Skeletal muscle has its own hierarchical organisation. Skeletal muscle is composed of many individual muscle fibres that are in turn made up of smaller fibres called myofibrils. Each myofibril is composed of smaller components – namely, thick filaments called myosin and thinner filaments called actin (see Figure 1.24). Myosin has special arms that are called cross-bridges. The cross-bridges must extend out, attach to and move actin. These filaments then slide past each other to cause movement. The process is sometimes known as the cross-bridge cycle or the sliding filament theory.

LEARNING SKILLS

Myofibrils Bundles of actin and myosin filaments found within some muscle cells Myosin A muscle protein involved in muscle contraction Actin A protein found in muscle and involved in muscle contractions Cross-bridges The ‘arms’ of the protein myosin, and are heavily involved in muscle contractions

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

Muscles: Muscles are made up of many layers. The first major layer of muscles is muscle fibres (also known as 'muscle cells').

Z band

Z band

Z band

Myosin filaments Actin filaments Overlap

Muscle fibre: Each is made up of smaller components known as myofibrils.

Myofibril: Myofibrils contain the contractile components of muscles. These components are two special filaments often known as a thick filament (myosin) and a thin filament (actin).

Figure 1.24 The microscopic structure of muscle tissue

TIP

Adenosine triphosphate (ATP) Consists of one adenosine molecule and three inorganic phosphate molecules, and is heavily involved in providing energy to the body Sarcomere The basic contractile unit of a myofibril Motor unit A motor nerve and all the muscle fibres it innervates Neuromuscular junction The site where nerves and muscles meet Acetylcholine The neurotransmitter sending messages to the muscle from the nerve

TIP Summation The combined force produced by motor units firing at the same time

In order for movement to occur, the body engages a series of chemical reactions to make energy. As introduced earlier, the human body stores this energy in the form of a high-energy compound called adenosine triphosphate (ATP). This compound consists of three phosphates and one adenosine group. The removal of one phosphate group – yielding adenosine diphosphate (ADP) – releases the stored energy that can be used for body reactions. Energy production is discussed in more detail in Chapter 2. A basic contractile unit of a myofibril is called a sarcomere. Sarcomeres can be thought of as repeating sub-units within skeletal muscle, giving it its striated appearance. A muscle can have hundreds of thousands of sarcomeres. The muscle contraction begins with the nervous system stimulating the muscle. The brain sends messages to the spinal cord, which in turn sends messages to the muscles via motor nerves. A motor nerve and all the muscle fibres it innervates are known as a motor unit. The number of muscle fibres a nerve innovates vary. The terminal ends of the nerve cell (axon) reach for the muscle at the neuromuscular junction (the site where the nerve and muscle meet). Nerve endings and muscle cell membranes never touch because of a small space between them called the synaptic cleft. When the nerve impulse reaches the neuromuscular junction, a chemical called acetylcholine is released into the synaptic cleft. If enough acetylcholine is released into the synaptic cleft, an electrical current is generated and causes muscle contraction. The message from the nervous system causes calcium to be released into the muscle fibres. Two important proteins block the attachment sites on the actin filament when the muscle is resting. The myosin cross-bridges cannot attach to actin, and so the filaments cannot move. The interaction of calcium with proteins unlocks the cross-bridges so they can attach to the actin-binding sites. When energy is provided by the breakdown of ATP, the muscle contracts. Relaxation of the muscle will occur when the nervous-system stimulation to the muscle ceases, causing calcium to be removed from within the muscle fibres. The mechanical action of the cross-bridge cycle is much like the one involved when climbing a rope. The greater the number of motor units recruited for the muscle contraction, the stronger the muscle contraction will be. Also, if the motor units fire in unison the muscle contraction will be stronger than if the motor units fire intermittently. The combined force produced by the motor units firing in unison is known as motor unit summation.

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CHAPTER 1 Anatomy and physiology A stimulus that is strong enough to trigger an electric signal will activate all the muscle fibres in a motor unit – this is known as the ‘all-or-none’ principle, which is discussed later in this chapter. Each motor unit is given a message by a nerve, causing release of a neurotransmitter. The neurotransmitter causes brief periods of muscle activation known as a muscle twitch. The sum of all these muscle twitches causes greater force to be achieved. The more motor units recruited, the higher the force will be. A motor unit contains only one specific muscle fibre type. The signal will either activate all the muscle fibres in the motor unit, so that they contract at the same time, or it will not. Specific exercise training can help to modify the unique metabolic characteristics of different muscle fibre types, making them more efficient. The human body can control the forces it produces by varying the number of motor units in a single contraction. Think about our ability to lift an apple to eat compared to a biceps curl using a 20-kg dumbbell. Both actions require the use of force, but the number of motor units and muscle fibres involved varies, to control the strength of the contraction. The speed at which you can move an object will vary, but your options for speed will decrease as the weight increases.

Muscle tension The tension exerted by a muscle as it shortens is affected by: • the initial length of muscle fibres • the angle of pull of the muscle (versus gravity or not) • the arrangement of muscle fibres. If the muscle fibre runs parallel to the centre of the entire muscle axis, the muscle fibre length will be the same as the length of the muscle as a whole. For example, the muscle fibres of the biceps brachii run in the same direction as the biceps muscle axis (this is called fusiform alignment), allowing the force generated to transmit directly to the tendon. This alignment allows for a very efficient movement – that is, fast production of force. When muscle fibres lie at more of an oblique angle to the tendons, the entire muscle has a larger cross-sectional area (called unipennate alignment) than a fusiform muscle. In this case, there are more sarcomeres to contribute to force production. The end result is that these muscles are relatively stronger, but slower in force production, than a fusiform muscle. They also generally have a more limited range of motion. Understanding the muscle alignment and the potential tension created by each muscle can help explain why some muscles are more predisposed to injury than others. For example, let’s look at the alignment of the opposing thigh muscle groups: quadriceps and hamstrings. Quadriceps generally have a force capacity about 50 per cent greater than that of the hamstrings, which are designed for rapid shortening. The force of quadriceps and the fast-contracting nature of hamstrings make hamstrings quite susceptible to tears during sprinting, when there is an imbalanced force output between the hamstrings and the quadriceps. During isometric contractions, the optimal sarcomere length is when there is greatest interaction between actin and myosin filaments. If the muscle is in a stretched state, less tension is generated compared to the resting state.

Muscle fibre types Muscle fibres can be classified as either slow-twitch (ST) or fast-twitch (FT). ST muscle fibres are also known as type I muscle fibres, while FT fibres are known as type II muscle fibres. Genetics determine the ratio of FT to ST muscle fibres in different muscles in human beings, so that some people have genetics on their side for certain sports. However, these people still have to train to maximise the advantage of their genes. See Table 1.10 for a comparison of the two types of muscle fibres.

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TIP

Muscle twitch A brief period of muscle activation

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

Table 1.10 Comparison of fast- and slow-twitch muscle fibres

Aerobic The production of energy with the use of oxygen Anaerobic The production of energy without the use of oxygen

TIP

Characteristic

Fast-twitch

Slow-twitch

Strength of contraction

High

Lower

Fatigue resistant

Low

High

Contraction speed

Fast

Slow

Colour under microscope

White

Red

Endurance capacity

Low

High

Respiration

Anaerobic

Aerobic

Diameter of muscle fibre

Large

Small

There are two types of FT muscle fibres: • FTa (fast-oxidative glycolytic, or FOG) muscle fibres, which are useful for both aerobic and anaerobic events such as a 1.6-km run • FTb (fast glycolytic, or FG) muscle fibres, which are useful for anaerobic events like the 100-m sprint. It is possible for a person with a high ratio of FT to ST fibres to improve their endurance capacity; however, an endurance athlete is likely to have a high ratio of ST to FT fibres. It is difficult to significantly improve the anaerobic capacity of ST, and hence the potential to improve the sprinting ability of this type of athlete may be somewhat limited. The proportion of ST to FT muscle fibres is usually determined by genetics, and training can cause some changes. Generally, men tend to have larger muscle fibres than females. Elite sprinters tend to have a majority of FT muscle fibres, while elite endurance runners possess a tendency towards a majority of ST muscle fibres in their major muscle groups. Middle-distance event athletes tend to have an even (i.e. 50/50) percentage of FT to ST muscle fibres. Strength and power training results in enlargement of the contractile ability of a muscle fibre, as well as an increase in the muscle fibre’s ability to use glycogen.

Muscle fibre types and activity ST muscles are predominantly used in prolonged aerobic exercise, and if there is some glycogen remaining in the muscle it is mostly in the relatively ‘unused’ FT muscle fibres. Endurance-trained athletes have the ability to fire some motor units while others recover, and this reduces fatigue. Both FT and ST muscles are used in middle-distance events and in sports such as soccer, netball, basketball and tennis, which use a combination of aerobic and anaerobic energy sources. With this in mind, training should incorporate training of both energy sources. FT muscle fibres are predominantly used in explosive events, such as power lifting. In these types of events, a quick, strong contraction is required, and training the FT muscle fibres and anaerobic energy sources is essential to improving performance.

TIP Enzyme A substance produced by a living organism that helps speed up natural processes such as digestion

FT (type II) muscle fibres produce a rapid and large force relative to ST (type I) muscle fibres because: • they have a high capability for transmitting an electrical signal • their cross-bridges work faster • the activity of the enzyme myosin ATPase (responsible for ATP breakdown) is faster • there is a relatively rapid release and use of calcium in the muscle.

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CHAPTER 1 Anatomy and physiology ST (type I) muscle fibres have a red pigmentation due to abundant mitochondrial and myoglobin levels. Compared to FT (type II) muscle fibres they are fatigue-resistant and more appropriate for aerobic types of exercise. ST muscle fibres, in comparison to FT muscle fibres: • transmit an electric signal more slowly • have lots of mitochondria (for breakdown of ATP with the use of oxygen) • have low myosin ATPase levels • have lots of myoglobin • are highly fatigue-resistant • have a higher blood flow.

TIP

Muscle fatigue Fatigue is the reduction in muscle tension in a given time period. Fatigue in skeletal muscle can occur along one or more of the parts involved in a muscle contraction, in the nervous system, in the neuromuscular junction or in the muscle fibre itself. Usually, the main reason for fatigue during prolonged exercise is the lack of fuel (glycogen) within the active muscle fibres, no matter how much oxygen is available. This is known as nutrient fatigue. There may also be a lack of oxygen to provide the energy requirement. An increase in blood and muscle lactate can contribute to fatigue. If the action potential fails to cross the neuromuscular junction, the fatigue is known as neural fatigue. Further research into the exact mechanisms behind this is required. 1 What is a motor unit? 2 If your client is struggling to compete in running hills during a distance run, how can you train them to perform better? 3 Slow-twitch (ST) and fast-twitch (FT) muscle fibres have been noted to favour different types of physical activity. In the table below, choose which fibre type would mostly be used for the following activities. An example has been completed to guide you. Physical activity

ST, FT or a combination

Marathon running

ST

WORKOUT 1.7

50-m freestyle swim Basketball Shot put

4 Research the resistance training exercise that will help to strengthen the muscles listed in the following table: Muscle

Strengthening exercises

Abdominals Triceps Hamstrings Biceps Quadriceps femoris Deltoids Wrist extensors Wrist flexors Gastrocnemius Soleus Tibialis anterior



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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING



Muscle

Strengthening exercises

Gluteus maximus Latissimus dorsi Pectoralis major Trapezius Serratus anterior Rhomboids External oblique Internal oblique Transversus abdominis Rectus abdominis Erector spinae

5 Fill in the following table as a class: Common exercise

Prime mover

Antagonist/s

Synergist/s

Fixator/s

Push-up Sit-up Chest press Chin-up Lat pull down Seated row Abdominal crunch Squat Leg press Lunge

Spinal curves and ideal postural alignment

Lordosis Excessive forward curve in the lumbar and cervical parts of the spine Kyphosis Excessive backward curve in the thoracic spine

The human spine has natural curvatures that help in weight-bearing ability against the forces of gravity. These natural curvatures in the spine occur where the cervical and lumbar spine have a concave (forward) curve and the thoracic spine has a convex curve (towards the back). If these curves are excessive, we can have postural problems such as lordosis (forward head carriage) or kyphosis (humpback appearance), as shown in Figure 1.25. A simple and quick way to analyse standing posture when the client is viewed from the side is to see whether the ear lobe, shoulder, hip, knee and anterior ankle are in a straight line. Deviations from this imaginary line may help to highlight postural problems. From a front-on view, the shoulders and hips should be in line in the horizontal plane. If one of the shoulders or hips is lower than the other, it may indicate that the spine is not straight, and if the difference is significant, it may indicate scoliosis. Postural concerns that may place a client at risk during exercise should be referred to an allied health professional such as a physiotherapist. The fitness instructor should always screen clients (see Chapter 3), use professional judgement and study each case on its merits before prescribing exercise. Poor postural and training habits, such as performing chest flys (on a pec deck machine) with a limited range of motion can contribute to rounded shoulders. This may contribute to increasing kyphosis in the thoracic region, especially when the upper-back muscles are not being trained. Similarly, having weak abdominal muscles and excessive weight in the abdominal area (a ‘beer gut’) may contribute to an increase in the lumbar curvature, causing an increased lumbar lordosis. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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CHAPTER 1 Anatomy and physiology

Scoliosis

Kyphosis

Lordosis

Figure 1.25 Spinal curves Remember to stretch what is tight and strengthen what is weak! Scoliosis is an abnormal sideways curvature of the spine that can occur because of genetic tendencies or postural habits – for example, in sports such as tennis that rely a lot on one side of the body. Anterior or posterior pelvic tilts can also be caused by muscle imbalances – for example, a tight iliopsoas (hip flexor) may promote an increase in anterior pelvic tilt. In contrast, it is possible that genetics may contribute to an increased anterior pelvic tilt within part or all of an entire family. In this case, the alignment can contribute to the muscle tightness. Knee alignment also varies among exercise clients. Genu varum (bowed legs) and genu valgum (‘knock-knees’) can predispose a person to injury and lack of movement efficiency. See Workout 1.8 to check your understanding of spinal curves and postural alignment.

1 Describe ideal postural alignment from both a side-on and a front-on view. 2 You have a client with a sedentary lifestyle (i.e. no structured exercise and a sedentary job). a Suggest some possible areas of muscle weakness for this client. b Research the name of exercises that you might consider for the client’s exercise program. c Suggest some possible areas of muscle tightness for this client. d What might you suggest to help the client overcome some of the muscle tightness?

TIP Scoliosis Abnormal sideways curvature of the spine Genu varum Abnormal curving of the legs resulting in separation of the knees Genu valgum Abnormal curving of the legs resulting in contact of the knees and separation of the feet

WORKOUT 1.8

1.4  THE CARDIORESPIRATORY SYSTEM The cardiorespiratory system is a combination of the cardiovascular system and the respiratory system working together. One cannot survive without the other. The cardiorespiratory system is made up of the heart, the blood vessels and two lungs. The heart and lungs work together to ultimately provide the body with adequate levels of oxygen to enable survival. Oxygen is taken in from the air through ventilation (breathing) and then transported to the working muscles and internal organs via blood vessels. Once the oxygen has been used, waste products such as carbon dioxide and water must be expelled from the body.

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Cardiorespiratory system The combination of the cardiovascular and respiratory systems

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The respiratory system The respiratory system is responsible for ventilation, and therefore allows air to enter the lungs. Breathing can occur via the nose or mouth. From there, the air travels down to the lungs via a series of airways (passageways) outside and inside the lungs. The airways generally get smaller (and change names) on the way through the lungs (see Figure 1.26).

Pharynx

Trachea Right main bronchus

Left main bronchus

Bronchiole Pleura

Alveolar duct Alveolus

Pleural space

Alveolar sac

Figure 1.26  The respiratory system Alveoli Air sacs in the lungs that are the site where gases (such as oxygen and carbon dioxide) are exchanged between the lungs and the blood Gaseous exchange The swapping of gases (such as oxygen and carbon dioxide) between the blood and tissues

After breathing in, the air travels down the trachea (windpipe) before the trachea branches off into a left and right bronchus. This allows the air to travel into the left and right lungs, respectively. The trachea and bronchi are composed of stiff cartilage and smooth muscle. These airways secrete mucus to filter any dust or other particles in the air. The air travels through smaller airways in the lungs, called bronchioles, and finally into the alveoli (air sacs) of the lungs. The alveoli are surrounded by tiny blood vessels known as capillaries; both have thin walls allowing the air to pass through easily in a healthy individual. This process is called gaseous exchange and is explained in further detail later.

The mechanics of breathing The process of breathing involves the two phases: inspiration (breathing in) and expiration (breathing out). The lungs have no muscles and expand when the muscles surrounding them contract, allowing air to enter and escape. The size changes that take place in the lungs occur through different processes depending on whether a person is resting or performing physical activity. During inspiration, the lungs depend on the following muscles: • the diaphragm, which contracts and flattens from its resting dome-like position. • the intercostals, which contract and expand the rib cage. Together, the diaphragm and the intercostals increase the size within the rib cage, helping the lungs to increase in volume and allowing air to rush into the lungs as they expand. When we are breathing heavily during activity we require more oxygen to enter the lungs, and this is when more muscles are involved, such as the scalenus.

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CHAPTER 1 Anatomy and physiology During resting expiration, the muscles involved in inspiration relax and the lungs return to their resting size, and air is pushed out of the lungs. However, during exercise we need to get air out of the lungs to remove carbon dioxide. The abdominal muscles assist expiration by contracting and pushing the diaphragm upwards. The internal intercostals can also assist expiration by changing the position of the ribs and decreasing the size of the rib cage. See Figure 1.27 for more on the mechanics of breathing.

Chest expands Chest contracts Sternum Ribs Lung Diaphragm Diaphragm relaxes

Diaphragm contracts Inhalation

Exhalation

Figure 1.27 The mechanics of breathing At rest, the volume of air that can be breathed is typically around 6 L per minute. During exercise, the breathing rate increases to about 35–45 breaths per minute in healthy adults, but this may be as high as 60–70 breaths per minute in elite athletes, which helps them to get more oxygen into the body faster. 1 Research the acute and chronic effects (if any) of exercise on respiratory volumes and identify the muscles that are used during the following stages of respiration: Stage

WORKOUT 1.9

Muscles involved

Inspiration Relaxed expiration Forced expiration during activity

2 Research and compare the differences in oxygen consumption when a person is involved in activities such as walking, doing housework and sprinting.

The cardiovascular system The cardiovascular system is made up of the heart, blood and blood vessels.

The heart The heart is made up of cardiac muscle that contracts involuntarily and does not fatigue. Its role is to pump blood around the body and to the lungs. It works as a double pump, where the left side of the heart pumps oxygenated blood and the right side pumps deoxygenated blood around the body. There are four major heart chambers: two atria, which receive blood, and two ventricles, which pump blood out of the heart. The left atrium receives oxygenated blood from the lungs and pumps it into the left ventricle; on contraction, it forces the oxygenated blood out of the heart into the aorta and out to the rest of the body (except the lungs). The right atrium receives deoxygenated blood from the body, which is then pumped to the right ventricle; on contraction, it pumps blood away from the heart to the lungs via the pulmonary artery (see Figure 1.28). Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

Aorta The largest artery in the body. It carries oxygenated blood from the left ventricle out into the body Pulmonary artery Carries deoxygenated blood from the heart to the lungs

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Aorta Heart Superior vena cava

Pulmonary veins Left atrium

Pulmonary veins Blood vessels

Right and left pulmonary arteries Pulmonary trunk

Right atrium

Atrioventricular valves

Semilunar valves

Left ventricle

Inferior vena cava

Interventricular septum Right ventricle

Figure 1.28 The cardiovascular system

Blood and blood vessels

Plasma Makes up more than half of blood volume and contains salts, hormones, sugars and fats Red blood cells Components of blood that carry haemoglobin White blood cells The parts of blood involved in immunity Platelets The parts of blood responsible for stopping bleeding and for forming clots Blood vessels Hollow tubes that allow blood to be transported around the body (similar to how a hose allows water through it)

The function of blood is to transport oxygen, hormones, nutrients and waste products around the body. Aerobic training can cause small increases in blood volume. Blood contains many different components; namely: • plasma, which makes up more than half of blood volume and contains salts, hormones, sugars and fats • red blood cells, which carry haemoglobin • white blood cells, which are responsible for immunity within the body • platelets, which are involved in the clotting process. The levels of these blood components can change according to training and disease. For example, white blood cell count can change during illness. Red blood cells can increase when there is a high level of aerobic training. They do not have a nucleus, which means that red blood cells are unable to reproduce, and so the human body must keep making new ones. Blood vessels are tubes of various thicknesses that are responsible for getting blood around the body. This is similar to the plumbing system that transports water to areas in a house (see also Figure 1.29). Artery

White blood cells

Platelets

Red blood cell

Figure 1.29 Blood vessel and blood cells Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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CHAPTER 1 Anatomy and physiology Blood vessels can be divided into arteries, arterioles, capillaries, venules and veins. Arteries transport blood away from the heart and are often under the greatest pressure. They are blood vessels with thick muscular walls that are elastic to cope with pulsating blood flow. Most arterial blood is fully oxygenated because the blood is pumped all over the body to tissues that require oxygen for daily functions. The exception is the pulmonary artery, which carries deoxygenated blood from the heart to the lungs so the blood can be refreshed with oxygen. The largest artery in the body is the aorta, which has to cope with the most amount of force from the heart. As the aorta and pulmonary artery extend further away from the heart they begin to branch out, similar to the branches of a tree. Each branch has a different name, and they get successively smaller. The smallest arteries are called arterioles. Arteries have relatively thick, smooth muscle walls to help them pump blood around the body. Arterioles link with the tiniest blood vessels, called capillaries, which have very thin walls to allow the diffusion of gases (oxygen and carbon dioxide). Capillaries surround skeletal muscle and alveoli and connect the system of arteries to the system of veins.

Capillaries have very thin walls to allow gases to pass through easily.

The thin walls allow oxygen to pass through to the skeletal muscle so that it can be used, while the skeletal muscle can give back excess carbon dioxide to the blood so that it can be removed from the body. From here, the blood will eventually get back to the capillaries surrounding the alveoli in the lungs and the blood will become oxygenated; carbon dioxide can then be offloaded from the blood back into the lungs to be breathed out. (This swapping of gases is the process of gaseous exchange mentioned earlier in this chapter.) In order for blood to get back to the heart once it has reached the capillaries, another set of blood vessels is used. Small vessels called venules will accept blood from the capillaries and then transport the blood to larger veins. Veins do not have thick walls like arteries because veins do not have to withstand relatively large pressure. Veins are, however, quite expandable, since they can carry up to 75 per cent of the blood volume at any one time. They carry deoxygenated blood back to the heart. The exception to the rule is the pulmonary vein, which carries oxygenated blood back to the heart. Endurance training may cause the following adaptations: • Capillaries may become more extensive and allow greater nutrient and oxygen exchange during exercise. This provides a greater surface area of gaseous exchange, thereby making the process more efficient. • An increase in the number of mitochondria in muscles can occur in proportion to the training. Recall that myoglobin is the protein that binds oxygen in muscles and transports it to the mitochondria. Myoglobin levels tend to be highest in slow-twitch muscle fibres and in clients who have high levels of aerobic endurance.

Haemoglobin and exercise During exercise, there is a higher demand for oxygen to the working muscles. As outlined earlier, the oxygen-carrying protein in blood is haemoglobin. Endurance training can increase the amount of haemoglobin found in the blood and also make existing haemoglobin more efficient at carrying oxygen. Increased haemoglobin levels mean that there is an increased oxygen-carrying capacity of the body. Altitude training has been used to increase the aerobic capacity for exercise and sport. At high altitudes the available oxygen is low, which forces the cardiorespiratory system to acclimatise (adapt) and become more efficient, increasing the ability of the body to move oxygen. The aerobic benefits are evident when the athlete returns to lower altitude and last for approximately a week. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

TIP Arteries Blood vessels that carry blood away from the heart to the rest of the body Arterioles Small branches of an artery leading to capillaries

TIP Capillaries Small, fine blood vessels that form a network between the arterioles and venules

TIP Veins Blood vessels that carry mainly oxygen-depleted blood back towards the heart

Venules Very small veins that collect blood from the capillaries

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Cardiac output Cardiac output The volume of blood that is being pumped by the ventricle each minute

A measure of how much oxygen is moved around the body is cardiac output, which is described in litres per minute. In order for the oxygen demands of the body to be met (especially during exercise), the cardiac output must increase. This is achieved by increasing the heart rate (beats per minute, or BPM), which redistributes the blood from inactive body organs, such as the stomach, to the active muscles. There is also an increase in the respiratory rate during exercise. Cardiac output can be explained using the following formula: Cardiac output (litres per minute) = Heart rate (beats per minute) × Stroke volume (litres per beat)

NUMERACY SKILLS

Systolic blood pressure Refers to the maximum pressure on the arteries during the contraction phase (systole) of the heart Diastolic blood pressure Refers to the minimum pressure on the arteries during the relaxation phase (diastole) of the heart

Cardiac output is the product of two major components: 1 Heart rate: the number of times the heart beats per minute 2 Stroke volume: the amount of blood pumped by the left ventricle each beat. For cardiac output to increase during exercise, the heart rate (BPM) will increase while stroke volume will only have minimal changes. However, after periods of endurance training the heart can become much stronger and cause an increase in stroke volume at the same intensity of exercise. Consequently, resting heart rate and submaximal levels of exercise will be lower than before training, and the heart will not need to work as hard due to the efficiency of the heart. The resting heart rate of a sedentary, unfit individual is commonly more than around 60 BPM, while a fitter person is more likely to have a resting heart rate of less than 60 BPM. Resting heart rate is affected by many factors, including age, gender and smoking.

Blood pressure and circulation Blood pressure reflects pressure against the arterial wall (see Figure 1.30). It is measured in millimetres of mercury (mmHg). The technique of taking blood pressure is covered in detail in Chapter 4. The two measurements that are taken are: • systolic blood pressure, which reflects the contraction of the left ventricle and the stress it is under as it tries to pump blood out into the circulation. At rest, systolic blood pressure is approximately 120 mmHg • diastolic blood pressure, which reflects the relaxation of the heart and provides an indication of how easily blood is travelling from the arterioles to the capillaries. At rest, diastolic blood pressure is approximately 80 mmHg. Systolic pressure is measured when the heart contracts.

Vessel

Normal

Prehypertension

Hypertension

Diastolic pressure is measured when the heart relaxes between beats.

Figure 1.30 Blood pressure in a blood vessel

Vasodilation The widening of a blood vessel

The immediate effect of aerobic exercise is an increase in systolic blood pressure due to the increase in blood flow, but very little change to diastolic blood pressure. This occurs due to the vasodilation of blood vessels during exercise causing a decrease in pressure. Regular aerobic training can see a decrease in blood pressure over time, and this is a great health benefit for clients who have elevated blood pressure. Medical advice and clearance must be obtained prior to training a client with high blood pressure.

Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

CHAPTER 1 Anatomy and physiology During resistance-type exercise, blood pressure will rise, especially in the legs versus the arms. The American Heart Association reviewed studies examining the effects of resistance training on blood pressure. Contrary to past beliefs, it appears that there is now some support for the potential role of resistance exercise in lowering blood pressure (AHA, 2018). Research also suggests that resistance training may favourably affect some cardiovascular risk factors. More research, however, is needed to clarify the exact role of resistance training, as well as any resistance training prescription guidelines, in this area.

Maximal oxygen uptake (VO max) 2

Maximal oxygen uptake (or VO2 max) is a measure of aerobic fitness and is the maximal amount of oxygen that can be consumed and used by the body. At rest, humans require approximately 3.5 millilitres of oxygen per kilogram of body weight per minute to stay alive and well, and this need can increase to 35–85 ml/kg depending on cardiovascular fitness. VO2 max improves with endurance training (circuit and interval training are examples), and with this improvement will come tolerance to higher levels of training. Our capacity to improve VO2 can be dependent on factors such as genetics, gender, age and intensity of training, which may play a large role in the VO2 max levels achieved.

Immediate cardiovascular responses to exercise As exercise commences, the body redistributes the blood around the body to provide oxygen to the working muscles. The initial cardiovascular responses to exercise include: • increased blood flow to the coronary arteries of the heart as the heart rate increases • increased blood flow to the working skeletal muscles to allow movement • decreased blood flow to the kidneys to try and maintain fluid levels in the body • maintenance or slight increases in brain blood flow because the brain cannot afford a decrease in blood flow without dangerous consequences • increased cardiac output because the heart is working harder to get blood flowing out to the rest of the body • decreased blood flow to the digestive system because of the priorities elsewhere during this time – so do not eat too close to an exercise session! • increased blood flow to the skin to help rid heat from the body. Warm skin can help to warm the sweat, causing it to evaporate Evaporation of sweat is necessary to help cool you down. Sweat that trickles off you on humid days is doing little to cool you. Indiana Benjamin Fitness

Long-term cardiovascular adaptations to endurance training Many changes occur in the body as a result of endurance training, including: • a decrease in the heart rate at rest and during submaximal exercise because the heart is stronger and more efficient, and therefore does not have to beat as frequently • an increase in stroke volume at rest and during exercise as the heart becomes stronger and more efficient at pumping blood. This will allow an increase in cardiac output (once again, from a stronger, fitter heart) • heart weight and volume and the thickness of the heart walls can increase as a result of long-term aerobic training, making the heart stronger • blood pressure at rest and during submaximal exercise tends to reduce as a result of regular aerobic training • a significant increase in plasma volume may occur after 3–5 training sessions • increased oxygen extraction from the circulating blood due to effective delivery of blood to the working muscles and the working muscles being better trained to extract and use oxygen • an increase in the number of capillaries surrounding each muscle fibre and capillary density (number of capillaries relative to cross-sectional area). This enables greater nutrient and oxygen exchange during exercise and increases the reliance on fat as an energy source

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• an increased number of mitochondria and mitochondrial density in muscle, providing more energy for muscle contraction • increased myoglobin content • improved muscle glycogen stores at rest and a glycogen-sparing effect during exercise. This means the body is better able to use free fatty acids for energy during exercise • increased intramuscular triglyceride stores at rest and enhanced ability to break down fat (lipolysis) during exercise.

WORKOUT 1.10

1 Calculate the cardiac output for a client who has a heart rate of 106 and a stroke volume of 70 mL/minute. 2 What is the long-term effect of exercise on high blood pressure, and why? What types of exercise would benefit a client with elevated blood pressure? 3 Using this book and further investigation, fill in the following table about acute and chronic adaptations that occur in the body in response to endurance training. Consider the effects on the cardiovascular, muscular and skeletal systems. The first row has been filled in for you. Acute adaptation

Chronic adaptation

Why do they occur?

Mitochondrial density remains the same

Increase in muscle mitochondrial density

Increased demand for energy

4 Challenge yourself to the Heart Structure game, available at https://www.purposegames.com/ game/heart-structure-game.

LEARNING SKILLS

Neurons The cells of the nervous system

1.5  THE NERVOUS SYSTEM The nervous system is the control centre of the body that sends messages to the body cells through the neurons sending electrical impulses. This is achieved through three overlapping functions: 1 Sensory receptors feed information to the brain about what is happening in and around the body 2 Interpreting and processing of the information in the brain and spinal cord occurs; this is called integration 3 Neurons respond by motor output to a muscle or gland. The nervous system is divided into two principal parts: 1 The central nervous system (CNS) consists of the brain and spinal cord and is the major command centre of the nervous system. It is responsible for the integration of information from sensory inputs. It then sends a response that is dependent on reflexes, current conditions and past experiences. 2 The peripheral nervous system (PNS) is outside the CNS. It consists mainly of nerves (see Figure 1.31) that extend from the brain to the spinal cord. Spinal nerves carry information to and from the spine, and cranial nerves carry information to and from the brain. Human movement is regulated and controlled by the CNS – namely, the brain and the spinal cord. Internal and external stimuli cause the CNS to sort and decode any information, which is then transmitted to the skeletal muscle via nerves in the PNS. This causes conscious awareness of body movements. However, some movements can occur without conscious thought, such as cardiac (heart) muscle contractions and joint reflexes (see Figure 1.31). Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

CHAPTER 1 Anatomy and physiology Key: = Structure

Central nervous system (CNS) • Brain and spinal cord (see below) • Integrative and control centres

= Function

Peripheral nervous system (PNS) • Cranial nerves and spinal nerves (see below) • Communication lines between the CNS and the rest of the body

Sensory (afferent) division

Motor (efferent) division

• Somatic and visceral sensory nerve fibres • Conducts impulses from receptors to the CNS

• Motor nerve fibres • Conducts impulses from the CNS to effectors (muscles and glands)

Sympathetic division

Autonomic nervous system (ANS)

• Mobilises body systems during activity ('fight or flight')

Somatic nervous system

• Visceral motor (involuntary) • Conducts impulses from the CNS to cardiac muscles, smooth muscles and glands

Parasympathetic division

• Somatic motor (voluntary) • Conducts impulses from the CNS to skeletal muscles

• Conserves energy • Promotes ‘housekeeping’ functions during rest

CENT RAL NE R V OUS SY ST E M Brain C2

Spine C2 C3 C4

C3

PE R IPH E R AL NE R V OUS SY ST E M

C4 C5 C6 C7 C8

Cervical

C5 T1

T1 T2 T3 T4 T5 T6

T2 T3

C6

T4

Thoracic

T5

T7

T6

T8 T9

T7 T8

T10

C6

C5

T9

T11 C7

T10

T12 L1

C8

L2 L3 L4 L5

T11 T12 C6 L1

C8

C6 C7

C7

S3

C8

S4 S2

L2

S2, S3

Lumbar

S5

S1

L3

L4

L5

S1

S1

S2

Sacral

L5

(Front)

(Back)

L5

L4 L4

Figure 1.31 The nervous system Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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The PNS has two functional subdivisions: 1 The sensory division consists of nerve fibres that convey impulses from the senses and structures to the CNS. Sensory fibres convey the information from the skin, skeletal muscles, joints and visceral organs. 2 The motor divisions of the PNS transmit impulses from the CNS to the effector organs, such as muscle (to contract) and glands (to secrete substances). The motor division has two main parts: a somatic – conducts voluntary impulses from the CNS to the skeletal muscles b autonomic nervous system – automatically controls the smooth muscles, cardiac muscle and glands.

Nerve cells (neurons)

Synapses The junctions between two nerve cells (where there is a tiny gap)

Nerve cells are called neurons (see Figure 1.32) and are responsible for sending electrical messages throughout the body. Low-intensity, prolonged workouts tend to produce a more expansive neuromuscular junction (the site where the muscle and nerve meet), whereas intense exercise leads to greater dispersion of synapses (the slight gap between the muscle and nerve where the electrical signal travels from the nerve to the muscle via a neurotransmitter). An increase in muscle strength occurs with strength training, but much of the initial improvements occur because of alterations in the functions of the nervous system rather than any significant change in muscle size and cross-sectional area. Neural adaptations to exercise are of particular importance in elderly people participating in functional training. NEURON

Axon terminals (transmitters)

Dendrites (receivers)

Cell body

Schwann’s cells (they make the myelin) Node of Ranvier

Axon (the conducting fibre)

Nucleus

Myelin sheath (insulating fatty layer that speeds transmission)

Figure 1.32 The neuron Strength training improves the effectiveness of neural recruitment and excitability. Firing rates increase and there is more synchronisation in the entire system. There is also an increase in central nervous system activation.

TIP

Nerve cells have special characteristics; namely: • longevity – they survive for a long time! With adequate nutrition and care, they can survive for over 100 years • amitotic – when nerves are destroyed, they cannot replace themselves • very high metabolic rate – they do not survive for very long without oxygen. Even a slightly diminished oxygen supply can have long-lasting effects on neurons.

Reflexes Reflexes occur automatically when the body is placed in certain circumstances, and they occur without conscious thought. The reflex arc that causes reflexes is outlined below. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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CHAPTER 1 Anatomy and physiology

The reflex arc – role of sensory receptors during movement Reflexes are automatic, involuntary reactions to an internal or external stimulus on the body. Two reflexes, the stretch reflex and the inverse stretch reflex, are of particular interest to the fitness instructor and will be discussed shortly. The reflex arc is responsible for making these reflexes happen (see Figure 1.33).

Skin Stimulus at distal end of neuron

2 Sensory neuron

3 Integration centre

1 Receptor

5 Effector

4 Motor neuron

Association neuron Spinal cord (in cross-section)

Figure 1.33 The reflex arc The components of the reflex arc are as follows: • Receptor – receives the signal for the reflex to start • Sensory neuron – part of the special wiring of the nervous system that sends messages from the proprioceptor to the spinal cord • Association neuron – a special part of the spinal cord that sorts and organises the information ready to be sent back to the skeletal muscle • Motor neuron – the neuron that sends messages from the association neuron back to the skeletal muscle • Effector – the part of the body affected by the reflex, which in this case is skeletal muscle.

Proprioceptors and reflexes A receptor that is involved in movement, posture and locomotion is called a proprioceptor. These are special receptors found in the musculoskeletal system that detect where the body is in space and initiate various reflexes. Muscle spindles are proprioceptors found within skeletal muscle. They respond to changes in length and tension within a muscle. Muscle spindles are responsible for initiating the stretch reflex when the muscle is under stress. Golgi tendon organs are proprioceptors found within tendons near the point where tendon meets muscle. Golgi tendon organs respond to tension when the muscle shortens or stretches passively. Golgi tendon organs are responsible for initiating the inverse stretch reflex. The stretch reflex is initiated by muscle spindles that detect and respond to changes in muscle fibre length. The muscle spindle will fire off if the muscle is being stretched too rapidly; it causes the muscle to contract. Postural muscles are always receiving nervous-system information in relation to body balance, allowing quick corrections – such as rolling your ankle when walking. They work constantly to counteract the force of gravity in the upright position. The stretch reflex may be initiated in ballistic, or bouncy-type stretches, and so this type of stretching is not recommended for the general population.

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Proprioceptor A receptor involved in movement, posture and locomotion Muscle spindles Proprioceptors found in skeletal muscles Stretch reflex A muscle contraction in response to a muscle stretch Golgi tendon organs Proprioceptors found in tendons near the point where tendon meets muscle Inverse stretch reflex A muscle relaxation in response to a muscle stretch

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TIP

Proprioceptive neuromuscular facilitation (PNF) Stretching that aims to utilise reflexes to relax the muscle allowing further stretch than would have otherwise been possible

TIP

PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

Ballistic stretching may trigger the stretch reflex.

The inverse stretch reflex is initiated by excessive tension causing the Golgi tendon organs to fire off a message to the spinal cord, which in turn causes an inhibition of the muscle involved, making it relax. This reflex is thought of as a protective mechanism that seeks to minimise the impact of, or stop, excessive loads that may cause injury. Proprioceptive neuromuscular facilitation (PNF) stretching takes advantage of the inverse stretch reflex; in this form of stretching, a static stretch is followed by an isometric contraction of the same muscle against a resistance – for example, a partner or a wall. During the isometric contraction, the Golgi tendon organ is stimulated and initiates the inverse stretch reflex. The inverse stretch reflex causes muscle relaxation, and the muscle can then be further stretched statically. PNF stretching may trigger the inverse stretch reflex.

Neural adaptations to training Alterations in the nervous-system firing pattern can occur as a result of training. Motor-unit recruitment and the firing pattern to muscle can change with training. Much of the initial improvement that occurs from strength training can probably be explained by improvements in the firing pattern of nerves. Light exercise stimulates the recruitment of ST fibres while the larger forces involved in weight training recruit more FT fibres.

The ‘all-or-none’ principle of the neuromuscular system ‘All-or-none’ principle The concept that a nerve will not ‘partially stimulate’ a muscle – it either provides enough stimulation or does not

TIP

When a motor neuron is activated, all the accompanying muscle fibres in the motor unit contract synchronously (known as the ‘all-or-none’ principle). For this to occur, the electrical impulse from the nervous system needs to be sufficient in strength to initiate a muscle action. But how do we control the strength of contractions, from a power lift to handwriting? The sensory receptors detect the required force, the brain interprets the contraction required and sends a nervous impulse to the required motor units. The greater the required force, the more motor units recruited. All motor units in a muscle do not fire at the same time. In weightlifters, a large number of motor units will fire simultaneously in order to produce more force in a shorter period of time. In contrast, endurance athlete motor units will require some motor units to fire while others recover. As the amount of weight lifted increases, speed of movement is progressively limited.

Neuromuscular fatigue When muscle fatigue occurs due to fatiguing neurons, it is sometimes called neuromuscular fatigue. This occurs when fatigue is setting in in one or more parts of the nervous system: the central nervous system, the peripheral nervous system, the neuromuscular junction or muscle fibre.

WORKOUT 1.11

1 What is a motor unit? 2 Explain how a reflex action works and provide an example of a reflex. 3 What is PNF stretching? Explain how it works.

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CHAPTER 1 Anatomy and physiology

1.6  THE DIGESTIVE SYSTEM Structure and function of the digestive system The digestive system is responsible for ingesting food and breaking it down into nutrient molecules (see Figure 1.34), and then absorbing these molecules into the bloodstream. It then removes the remains in the form of faeces. There are two major groups of organs in the digestive system; namely, the: 1 alimentary canal, otherwise known as the gastrointestinal (GI) tract – the continuous muscular digestive tube that winds through the body. Its role is to digest food from large chunks into smaller parts and absorb digested fragments through its lining into the blood. The gastrointestinal tract consists of the following organs: –– Mouth –– Pharynx –– Oesophagus –– Stomach –– Small intestine –– Large intestine, which leads to its own external opening, the anus. Mouth – Breaks up food particles – Assists in producing spoken language Pharynx – Swallows

Salivary glands – Saliva moistens and lubricates food – Amylase digests polysaccharides

Oesophagus – Transports food

Liver – Breaks down and builds up many biological molecules – Stores vitamins and iron – Destroys old blood cells – Destroys poisons – Bile aids in digestion

Stomach – Stores and churns food – Pepsin digests protein – HCI activates enzymes, breaks up food, kills germs – Mucus protects stomach wall – Limited absorption

Gall bladder – Stores and concentrates bile Pancreas – Hormones regulate blood glucose levels – Bicarbonates neutralise stomach acid – Trypsin and chymotrypsin digest proteins – Amylase digests polysaccharides – Lipase digests lipids Small intestine – Completes digestion – Mucus protects gut wall – Absorbs nutrients, most water – Peptidase digests proteins – Sucrase digests sugars – Amylase digests polysaccharides

Anus – Opening for elimination of faeces

Large intestine – Reabsorbs some water and ions – Forms and stores faeces

Rectum – Stores and expels faeces

Figure 1.34 The digestive system

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2 accessory digestive organs – a set of organs and a number of digestive glands that are responsible for producing a variety of secretions that contribute to the breakdown of foodstuffs. These comprise the following organs: –– Teeth –– Tongue –– Gall bladder And the following digestive glands: –– Salivary glands –– Liver –– Pancreas. The teeth and tongue are in the mouth (oral cavity), while the digestive glands and gall bladder are outside the GI tract. They connect to the digestive system via ducts.

How does the digestive system work? Peristalsis The major means of propulsion of food through the gastrointestinal tract, involving alternate waves of contraction and relaxation of muscles in the organ walls Segmentation Rhythmic, local constrictions of the small intestine, involves the mixing of food with digestive juices, which increases the ease with which absorption can occur because the different parts of the food mass are moved repeatedly over the intestinal wall

Digestion is a highly complex bodily process. Food from your dinner plate has to be consumed via your mouth and it then has to go through a lot of mechanical and chemical processes to turn into a product that can be easily used for functions of the body. Let’s break down these digestive processes into six steps. After that, we will investigate more closely the role each organ plays in these processes. 1 Ingestion involves taking the food into the digestive tract, usually via the mouth. 2 Propulsion involves swallowing, and then the movement of food through the GI tract. This process starts off through the voluntary action of swallowing but then also includes the action of peristalsis, which is an involuntary process. 3 Mechanical digestion involves the physical preparation of food for chemical digestion by enzymes. In the mouth, food is chewed and mixed with saliva by the tongue; it is then churned in the stomach and undergoes segmentation in the small intestine. Segmentation involves the mixing of food with digestive juices, which increases the ease with which absorption can occur because the different parts of the food mass are moved repeatedly over the intestinal wall. 4 Chemical digestion is a process that involves the breakdown of food by enzymes that are released into the digestive tract. Essentially, it begins in the mouth and is generally completed by the time the foodstuffs arrive at the small intestine. 5 Absorption is where the digested end products, in addition to vitamins, minerals and water, are absorbed from the digestive tract through the walls into the blood or lymph. Most of the absorption occurs in the small intestine. 6 Defecation is the last step of the process, where any indigestible substances are released from the body via the anus in the form of faeces.

Digestive organs and accessory glands – what role do they play? Let’s now look more closely at the role of the major digestive organs and accessory glands in the digestive process: • Mouth: The mouth (oral cavity) is made up of the lips, cheeks, palate and tongue. It is responsible for mastication (chewing) and deglutition (swallowing). • Oesophagus: The muscular tube (about 25 cm long) that propels food from the mouth to the stomach. • Stomach: This organ serves as a temporary ‘storage tank’ for food after it has passed through the oesophagus. Here, the chemical breakdown of proteins begins and food is converted to a creamy paste called chyme. • Small intestine: This is a major digestive organ. It is a twisted passageway in which the digestive processes are completed. Almost all the absorption of products from the digestive system to its necessary locations occurs here. • Liver: This is the largest gland in the body. It is located under the diaphragm. The liver is a very important organ in the body and has many metabolic and regulatory roles. As far as its digestive Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

CHAPTER 1 Anatomy and physiology functions are concerned, its role is to produce bile for export to the duodenum. Bile is a product that is a fat emulsifier; in other words, it breaks down fat into smaller particles so that the digestive enzymes have an easier role in breaking them down further. The liver also processes nutrientladen venous blood delivered to it directly from the digestive organs. This is a metabolic rather than a digestive role. Bile salts also facilitate fat and cholesterol absorption. Many substances that are secreted in bile leave the body in faeces, but bile salts are not one of them – they get reused. • Gall bladder: Chiefly a storage organ for bile, the gall bladder is a thin-walled, green, muscular sac about 10 cm in length. It snuggles on the ventral (front) surface of the liver. It is a muscular wall that contracts to expel bile into its cystic duct. The bile then flows to the bile duct. • Pancreas: This is a soft, tadpole-shaped gland, with most of its structure lying deep within the greater curvature of the stomach. The pancreas is an accessory organ, with its role in digestion being to produce enzymes that break down all categories of foodstuffs, which the pancreas then delivers to the duodenum. It creates an exocrine product, known as pancreatic juice, which eventually drains from the pancreas via the pancreatic duct. The pancreatic duct generally fuses with the bile duct just as it enters the duodenum. The pancreas is also part of the endocrine system (which is responsible for producing hormones). • Small intestine: This is where most of the chemical digestion of food occurs. Carbohydrates and proteins are partially degraded, but virtually no fat digestion has occurred to this point. Chyme (partly digested food mixed with digestive juices) will generally spend about 3–6 hours moving through the small intestine, and it is here that absorption of most of the water and just about all of the nutrients occurs. • Large intestine: The major digestive function of the large intestine is to absorb most of the remaining water from the digested food residues, which are delivered in a fluid state; to temporarily store the residues; and then to eliminate them from the body as faeces. The primary concerns of the large intestine are the propulsive activities that force faecal material towards the anus and then eliminate it from the body in the process of defecation.

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Bile A fat emulsifier; that is, it breaks down fat into smaller particles, which are then further digested by digestive enzymes Duodenum The first part of the small intestine immediately beyond the stomach

A special word on fatty meals Bile salts are a major stimulus for enhanced bile secretion. When a fatty meal is eaten, the bile-salt output of bile rises dramatically. Also, when the intestinal walls are exposed to fatty chyme, a product called secretin is released, which stimulates the liver cells to secrete bile.

What is required for optimal digestion? Essentially, all the parts of the digestive system need to be working well for digestion to be optimal. Anything that impairs the functions of the liver or pancreas, or the delivery of their juices to the small intestine, severely hinders the ability to digest food and absorb nutrients. The digestive system’s absorptive cells effectively accomplish the other primary function of the small-intestine absorption. Optimal digestive activity in the small intestine, where most digestion and absorption actually occurs, depends on a slow, measured delivery of chyme from the stomach. It is important that this process does not happen too quickly; otherwise, the water loss from the small intestine would be too much, which is potentially dangerous to humans. Excessive alcohol and fatty foods can cause damage to the digestive organs, and this may disrupt the system’s ability to perform effectively.

1.7  ENERGY SYSTEMS Metabolism and making energy for movement In order for the muscles to contract during exercise, we require a chemical energy source. Our metabolism provides us with the physical and chemical processes that are necessary to maintain our energy. More specifically, basal metabolic rate (BMR) is the minimal level of energy that is necessary to sustain bodily functions to maintain life. A person’s BMR is crucial to the ability to reduce body fat Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

Basal metabolic rate (BMR) The minimal level of energy required to sustain life

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Adenosine diphosphate (ADP) Consists of one adenosine molecule and two inorganic phosphate molecules, and is required for the production of ATP

PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

and maintain weight control. Basically, BMR represents a person’s total energy expenditure in a day. Factors that influence BMR include the following: • Body mass: People with a larger muscular body mass (specifically, lean body mass, sometimes known as fat-free mass) have a high metabolic rate compared to fat. This is one of the reasons why resistance training is essential for improving levels of lean body mass and reducing body fat. High body fat has a negative impact on BMR. • Regular exercise enhances BMR: This is dependent on the intensity, volume and duration of training and the muscle mass involved. • Diet-induced thermogenesis: Eating increases metabolism. This involves the increase in metabolism associated with digestion, absorption and assimilation of nutrients. The sympathetic nervous system is also stimulated during digestion, further enhancing metabolism. Meals that are higher in protein content elicit a higher increase in metabolism and feelings of fullness (known as satiety). • Environment: Warm environments can increase metabolic rate because of the increased oxygen consumption required. The greater your core temperature, the greater the metabolic rate (however, take care at all times not to overheat your client). Cold temperatures also provide a stimulus to increasing metabolic rate because of the shivering that occurs as the body tries to warm itself up. Other factors influencing BMR include a low kilojoule intake, which can reduce metabolic rate and therefore lead to weight gain; and stress and hormones, which can also affect metabolism. The fuel source for the body is food, and sources of energy from carbohydrate, protein and fat are discussed in Chapter 2. The nutrient used will vary depending on the intensity of the exercise, fitness level and the level of nutrient stores within the body. Energy from food is made available for use by the body’s cells through the ATP molecule, which was introduced earlier. ATP is known as the body’s energy currency, with potential energy waiting to be used by the body’s cells. ATP is made up of one adenosine molecule and three phosphate groups. Energy is stored in the connections or bonds between the phosphates. These connections can be broken to cause the release of energy. However, the cell only has enough ATP stored for about three seconds of intense activity. After this, more ATP needs to be made. The chemical reaction that occurs to cause ATP to break down and release energy is reversible, meaning the human body can make more ATP. This occurs when there is available phosphocreatine (PC) in the working muscle. When ATP loses one phosphate group it leaves behind a new molecule called adenosine diphosphate (ADP). ATP

ADP + Phosphate (P) + Energy

An enzyme called ATPase (introduced earlier) assists the process of breaking down ATP. The energy activates specific sites along the muscle fibres causing them to shorten. ATP rebuilding will occur via a number of different energy systems or processes. The energy systems are sometimes termed differently, but include: • the creatine phosphate system (or ATP–PC system) • the lactic acid system (or anaerobic glycolysis) • the aerobic system (or aerobic respiration). The creatine phosphate system and the lactic acid system are grouped within the anaerobic system (oxygen is not required for the production of energy), but are required in the aerobic system. This is because neither of these systems directly requires oxygen to produce energy. The major differences between the three energy systems can be found in Table 1.11.

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Table 1.11 Energy systems Anaerobic Phosphocreatine (ATP–PC)

Aerobic Lactic

Intensity of activity

Very-high-intensity, short-duration activities

Moderate- to high-intensity exercise between 60–95% of maximum effort

Low- to moderate-intensity exercise

Duration

1–10 seconds of explosive activity

Varies depending on intensity, but usually up to about three minutes

At low intensity and with adequate fuel stores there is no limit to duration

Fuel

Creatine phosphate

Carbohydrate in the form of glycogen or glucose

Carbohydrate, fat and protein

Limitations and waste products

Small supply of creatine phosphate available; however, no waste products to limit performance

Lactic acid (which is the incomplete breakdown of carbohydrate) produced; may limit performance, but can also be reused as a fuel source

Water and carbon dioxide produced; water is expelled via sweat and urine, carbon dioxide is breathed out

Recovery time

Very quick recovery –30 seconds–2 minutes

It takes 20–120 minutes to break down lactic acid

Time to replace fuel stores

The phosphocreatine, or ATP–PC system Phosphocreatine (PC), also known as creatine phosphate (CP), is another molecule that stores large amounts of energy. PC is made of creatine and phosphate with a special connection or bond. When the PC bond is broken, energy is released which is used to rebuild ATP. This energy system is relatively quick, and is therefore most useful when exercise commences and for powerful explosive movements of short duration. This system does not leave behind any waste or end products, which is advantageous over other energy systems. The ATP–PC system is considered to be part of the anaerobic energy system because it does not rely directly on oxygen for energy production. The muscle can only store a limited amount of PC in the body, and creatine supplements are useful if there is a deficiency; any excess will be eliminated out of the body. This supplement will then be wasted if it is not used by the body. Phosphocreatine in the muscle providing anaerobic energy: PC Energy + ADP + P

C + P + Energy ATP

The lactic acid system The lactic acid system is considered part of the anaerobic energy system. It uses carbohydrate in the form of glucose or glycogen as its fuel. Glucose is found in the bloodstream, while glycogen is the stored version of glucose and is found in the muscle and liver. If there is insufficient glucose available to make ATP, the body can break down glycogen from the liver. The breakdown of carbohydrate is complex, and energy production in this system is not as quick as in the phosphocreatine system. The lactic acid system breaks down carbohydrate without the use of oxygen through a process called glycolysis. Glycolysis produces two or three ATP molecules from the breakdown of glucose molecules. The end product produced is pyruvic acid, which can then be converted to lactic acid through the anaerobic lactic acid system if insufficient oxygen is available (during moderate to highintensity exercise), or it can continue to the Krebs cycle in the aerobic system (also known as the citric acid cycle). If lactic acid is produced, it can diffuse out of the muscle into the bloodstream within 30 seconds of exercise stopping. The excess hydrogen ions produced by anaerobic glycolysis may limit performance by causing fatigue. Other factors that may limit performance include increased levels of inorganic phosphate, increased ADP and impaired calcium release into the muscle. The role of lactic acid Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

Glycolysis The breakdown of carbohydrate Lactic acid A compound produced when glucose is broken down and oxidised. During intense exercise, when oxygen levels are lower, more lactic acid is produced, which can produce hydrogen ions and a burning sensation in muscles while they are active Krebs cycle A complex series of chemical reactions occurring in the mitochondria that completely oxidise (break down) fuel molecules to produce a large amount of ATP; also known as the citric acid cycle

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and limiting performance factors are highly contentious issues. Further scientific investigations are warranted to clarify the role and impact of each potential limiting factor on performance. This energy system works more slowly than the phosphocreatine system but faster than the aerobic system. It is mostly used for intense exercise lasting up to about three minutes. Fitness levels, nutrient supply and the build-up of lactic acid will also affect the duration for which the lactic acid system will last as the major supplier of energy for exercise. When a muscle contracts vigorously at about 70 per cent of maximum for an extended period of time, the bulging muscles compress blood vessels within them, which impairs blood flow and therefore glucose and oxygen delivery. Under these conditions, the relatively slow aerobic system cannot function quickly enough to keep pace with the demands for ATP production.

The aerobic system The aerobic system uses oxygen during the process of making ATP and produces a large amount of ATP. The amount of ATP will be determined by which fuel source is used (carbohydrate, fat or protein). At rest and during light aerobic exercise, muscle metabolism is almost entirely aerobic and fat is used to produce ATP. As exercise intensity increases, carbohydrate becomes available as a fuel source because the breakdown of fat cannot supply energy quickly enough. In extreme exercise situations, protein may be used to make ATP. The aerobic system makes ATP within the mitochondria of the muscle cell. Fitter people have more densely packed mitochondria within the cells. The waste products of this system are water and carbon dioxide. Breathing out rids the body of carbon dioxide, while the water is lost through urine and sweat.

Lactic acid or lactate – ‘waste’ or not? While we have looked at the three energy systems separately, in reality the systems all work together to provide the body’s energy requirements during exercise. For example, during a marathon the major energy provider will be the aerobic system; however, when the runner approaches a steep hill the anaerobic system will become the predominant provider of energy. When there is a lack of oxygen, pyruvic acid is converted into lactic acid, and it was once believed that the accompanying increases in muscle and blood lactate were related to the onset of fatigue. However, it should be remembered that lactic acid can be formed at any time during energy production as long as glycolysis is taking place, regardless of whether or not oxygen is present. The process of glycolysis produces lactic acid. Lactate can be cleared from the blood through oxidation within the muscle fibres in which it was produced or can be transported to other muscle fibres for oxidation (so it can be used again as an energy source). Therefore, it now appears unlikely that lactate is as much the ‘fatiguing factor’ during exercise as once thought.

The energy systems and adaptation to training

Steady state Occurs during exercise when heart rate reaches a level to maintain the circulatory demands of the body to meet the rate of work

The energy requirements of the body will vary significantly between rest and exercise. At rest, the body uses mainly fat and carbohydrate as energy sources. Lactic acid is formed at rest and during light exercise, but build-up of lactic acid does not occur, because other tissues continually remove it. Blood lactate does not accumulate for all exercise intensities. Energy demands may be adequately met by the aerobic system at low intensity even in most untrained people. As exercise intensity increases, it is more difficult for oxygen to be supplied to the working muscle and lactic acid begins to accumulate. Lactic-acid accumulation may also occur in sports where FT muscle-fibre recruitment is maximised. These fibres rely heavily on the lactic acid system. Sprint and middle-distance athletes can improve their capacity to break down carbohydrate and use it for energy through the lactic acid system as a result of high-intensity, short-duration training. Aerobic exercise training may lead to increased blood flow to the heart and improved gaseous exchange at the capillaries. It can delay the accumulation of lactic acid that occurs at higher exercise intensity. The athlete can then delay the fatigue associated with lactic acid build-up. Trained and untrained individuals may achieve a similar oxygen uptake once steady state has been attained. Steady state occurs when the heart rate reaches the optimal level to meet the circulatory demands for that specific rate of work, so that the heart rate remains steady. This usually occurs within Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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CHAPTER 1 Anatomy and physiology one to two minutes of increasing the intensity. However, the more intense the exercise, the longer it takes to achieve steady state. A trained individual will reach steady state more rapidly compared to an untrained person. The trained person will be able to consume more oxygen and be more efficient at using the aerobic system than the untrained person. VO2 max can increase with aerobic training as the ability to consume, transport and use oxygen during exercise improves. As training intensity increases within any training session, the demand for oxygen also increases. There is a point at which the body cannot supply the oxygen as fast as it is needed and the body must supply more of its energy from the anaerobic system. This is called the anaerobic threshold. A fitter person will take longer in the training session to reach anaerobic threshold. Blood-lactate accumulation is greater in high-intensity, intermittent exercise, such as sprinting and resistance training, compared to low-intensity, continuous exercise. If exercise intensity is light to moderate, therefore allowing sufficient oxygen to be available to the working muscles, blood lactate does not accumulate because removal will exceed production. The lactate threshold is the exercise intensity at which blood lactate begins an abrupt increase above baseline concentrations. (See Chapter 10 for more on this topic.) 1 In the table below, identify which energy system is the predominant provider for the relevant activity. The first one has been done for you. Activity

Energy system

Marathon run

Aerobic

Anaerobic threshold The point at which the body starts to rely more on anaerobic energy sources rather than aerobic energy sources

WORKOUT 1.12

Power lift 400-m sprint 50-m freestyle swim Shot put Netball match

2 Identify the amount of energy and waste products produced by the three energy systems.

Online games and other resources are sustainable, mobile and reduce the need for paperbased resources. • For a free online product that provides 3D views of the systems of the body, see http://www.anatomylearning.com/en/. • Bio-digital online 3D visual models to enhance learning are available at https://human.biodigital.com/signin.html. (Note that this page requires you to sign up.)

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LEARNING SKILLS

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Chapter summary The study of anatomy and physiology is very important when learning how to instruct fitness clients. Without knowing how the body works, you will be unable to plan and instruct effective fitness programs that actually achieve what the client wants to achieve. Learning the ins and outs of the human body can be tricky at first, particularly because much of the language is different from what you are used to hearing. It is useful to ‘practise as you learn’; for example, think about the bones and joints that are being moved, and which muscles are moving them, when you train. Think about how this differs from one exercise to the next. It is also vital that you understand the functions of the body’s systems. When you develop fitness programs, think about how long it will take a client’s cardiovascular system to improve so that the person can run that extra kilometre or climb that extra flight of stairs without huffing and puffing. All the body systems are interlinked, and one really does not function well without the others. Muscles rely on oxygen to do their work. The cardiovascular system needs to pump that oxygen around the body in the blood. The respiratory system needs to take in that oxygen from the air. The nervous system needs to signal the body parts to do their job, and the digestive system is the cornerstone of the body getting the energy it needs.

Review questions 1 Choose three weight-training exercises. List the muscles, movements and joints that are used in them. 2 List the three planes of the body and identify the regions that are formed by each plane. 3 Explain the role of the cardiovascular system and any changes that may occur in it due to training. 4 Explain the role of the digestive system and any changes that may occur in it due to training. 5 What is blood pressure? Identify: a the two measurements that are taken b what is occurring when the two measurements are taken c the immediate effect on blood pressure of an exercise session d a long-term effect of training on blood pressure. 6 What muscle fibre adaptations are likely to occur as a result of the following? a Aerobic training b Strength training (high-weight, low repetitions) c Endurance-based resistance training (low-weight, high repetitions). 7 What is the function of the digestive system, and what are the main structures of the system? 8 How does the body produce energy? Identify the three methods of energy production. 9 What are the limiting factors to continued exercise?

CASE STUDY 1.1 Joe is an inactive 42-year-old man who wants to decrease body fat and increase muscle mass to be stronger and look better. 1 What type of exercise would you prescribe for Joe? 2 Explain which body systems would be used for each type of training you prescribe.

CASE STUDY 1.2 Jan is 25 years old and gave birth to her first child six months ago. She experienced mild lower-back pain during her pregnancy, which has failed to subside since the birth of her baby. Her physiotherapist has recommended that she commence a strengthening program for the muscles supporting her lower back. 1 Research suitable exercises for Jan to achieve her goals, assuming that the physiotherapist supports this approach.

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CHAPTER 1 Anatomy and physiology

CASE STUDY 1.3 Suzie is an office worker who spends her working day on a computer. She experiences neck and thoracic pain at work when she works at her computer for at least six hours per day. Her doctor has referred her to a chiropractor to assess possible kyphosis, develop a management strategy to assist her condition and possible strategies that may help her pain at work. The chiropractor has identified that the following muscles require an endurance-training program to cope with Suzie’s workload: • Rhomboids • Posterior deltoid • Middle to lower trapezius • Erector spinae • Transverse abdominis • Internal oblique. The chiropractor has also identified that the following muscles will require a stretching program: • Iliopsoas • Pectorals • Upper trapezius • Anterior deltoid. 1 Provide Suzie with a home exercise program to help improve her posture. (You may need to refer to content from other chapters in this book.) 2 Suggest some strategies that may help Suzie while she is at work on her computer. Think about the practical set-up of the computer and some exercises she can do while at work.

Weblinks Get Body Smart https://www.getbodysmart.com/ Healthline: ‘The human body’ https://www.healthline.com/human-body-maps Introduction to anatomy & physiology: Crash course A&P #1 (video) https://www.youtube.com/watch?v=uBGl2BujkPQ&list=PL8dPuuaLjXtOAKed_MxxWBNaPno5h3Zs8

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2

Nutrition

OBJECTIVES This chapter involves application of the following topics: 2.1 Providing healthy eating information to clients 2.2 Understanding the Australian Dietary Guidelines 2.3 Understanding the scope of practice for an Australian fitness instructor 2.4 Providing information on a balanced diet and nutrition 2.5 Supporting positive attitudes towards eating and body composition 2.6 Referrals to accredited practising dietitians, accredited sports dietitians, general practitioners (GPs) or allied health professionals

LO

INTRODUCTION Chronic diseases Health conditions that do not resolve spontaneously and are generally not cured completely. While some can be immediately lifethreatening, such as chronic heart failure and stroke, others persist and, often, progress over time. They are not always a cause of death (e.g. arthritis is considered a chronic disease)

Australians’ eating patterns have a significant impact on the prevalence of chronic diseases. A healthy diet, in conjunction with physical activity, can often prevent conditions such as obesity and type 2 diabetes. The Australian Institute of Health and Welfare (AIHF) has estimated that in 2014–15, 1.2 million Australians had diagnosed diabetes, with 85 per cent of those diagnosed having type 2 diabetes. This is an increase from 2007–8, when it was estimated that 787 500 Australians had type 2 diabetes (AIHW, 2015). According to the AIHW, diabetes is also increasingly being diagnosed in younger people (AIHW, 2011). There is an increasing expectation that Australian fitness instructors will provide nutritional advice to help clients manage or lose weight, and it can be confusing for the fitness instructor to know what advice they are qualified to provide within the level of their qualification. In this chapter, we will outline the risks of stepping outside the scope of practice of a fitness instructor and the possible consequences of doing so. Fitness instructors should provide nutritional advice based on the Australian Dietary Guidelines (NHMRC, 2013a), which will be covered in greater detail throughout this chapter.

2.1  HEALTHY EATING According to the National Health and Medical Research Council (NHMRC), publishers of the Australian  Dietary Guidelines (NHMRC, 2013a), there are many ways in which Australians can achieve  positive dietary patterns that promote health and wellbeing and prevent chronic disease.

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CHAPTER 2 Nutrition Diet  is an important behavioural factor that can be improved to create lasting effects on health. Optimal nutrition is essential for: • normal growth • physical development • cognitive development • improving resistance to infection • protection against chronic diseases and premature death (NHMRC, 2013a, p. 1). Suboptimal nutrition is associated with ill health and with many chronic diseases, such as: • cardiovascular disease (disease of the heart and blood vessels) • type 2 diabetes (disease of the pancreas, causing trouble with the regulation of blood glucose – also known as blood sugar – in the body) • some forms of cancer (NHMRC, 2013a, p. 1). Much of the burden of chronic disease in Australia can be associated with: • excess intake of energy-dense and relatively nutrient-poor foods and drinks – that is, foods and drinks high in energy, saturated fat, added and/or refined sugars or salt, and which offer little nutritional value • inadequate intake of nutrient-dense foods, including vegetables, fruits and wholegrain cereals (NHMRC, 2013a, p. 1) • lack of regular exercise • lack of regular incidental physical activity (basically, people sit too much!).

Social determinants influencing food choices Social factors often influence food choices. The NHMRC has identified some causes of health inequities outside the healthcare system. These factors are: • employment • income • education • cultural influences and lifestyle • language • sex and other genetic differences • isolation (geographic, social or cultural) • age and disability • the security and standard of accommodation • availability of facilities and services (NHMRC, 2013a, p. 2). Poor health status can also contribute to social isolation and limit a person’s capacity to gain employment, education and an income, which can in turn have a negative impact on the quality and stability of housing they have access to and compound and reinforce poor diet choices (NHMRC, 2013a, p. 2). There are complex relationships between dietary patterns established in childhood and dietary quality over time (NHMRC, 2013a, p. 8). For example, a reliance on take-away and highly processed foods in childhood may result in limited choices in adulthood due to a lack of experience in preparing fresh food. This may in turn be associated with a reduced intake of fresh vegetables and dietary fibre. Family meal patterns during adolescence may also be used to predict diet quality and meal patterns during early young adulthood (NHMRC, 2013a, p. 8). Before we look at the Australian Dietary Guidelines in detail, let’s look at the Australian Guide to Healthy Eating (see Figure 2.1). This is a visual tool that your clients can use to get an idea of how much food they should be eating from each food group.

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

Figure 2.1 The Australian Guide to Healthy Eating Source: National Health and Medical Research Council

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CHAPTER 2 Nutrition

2.2 THE AUSTRALIAN DIETARY GUIDELINES Over the years, several different versions of the Australian Dietary Guidelines have been published and, although the guidelines have not changed substantially, the evidence base supporting them has strengthened considerably (NHMRC, 2013a, p. 8). Fundamentally, healthy eating should consist of a variety of foods from each food group: breads and cereals (preferably wholegrain), vegetables and legumes, fruit, milk and milk-based products (such as yoghurt and cheese), lean meats and meat alternatives (such as legumes), fish and poultry. We should also be drinking lots of water and eating small amounts of fats and sugars. Each group provides different nutrients to the body and helps prevent many illnesses. The Australian Dietary Guidelines were republished in 2013 (NHMRC, 2013a). They can be accessed from the NHMRC website (http://www.nhmrc.gov.au); however, the following section will present an overview of the Australian Dietary Guidelines and outline how you can provide clients with information about the guidelines while staying within your scope of practice as a fitness instructor. There are five guidelines in the Australian Dietary Guidelines, which can be summarised as follows: • Guideline 1: Achieve and maintain a healthy weight. • Guideline 2: Enjoy a wide variety of nutritious foods. • Guideline 3: Limit intake of foods containing saturated fat, added salt, added sugar and alcohol. • Guideline 4: Encourage, support and promote breastfeeding. • Guideline 5: Food safety (including how to prepare and store food safely). NHMRC, 2013a, p. v

LEARNING SKILLS

We will now look more closely at each guideline in the Australian Dietary Guidelines to gain a better understanding of how fitness instructors can provide this information to clients in addition to supporting positive attitudes towards eating and body composition.

Guideline 1: Achieve and maintain a healthy weight The following is from Guideline 1 of the Australian Dietary Guidelines: To achieve and maintain a healthy weight, be physically active and choose amounts of nutritious foods and drinks to meet your energy needs. [This is based upon the age, gender and activity levels of healthy clients.] Children and adolescents should eat sufficient nutritious foods to grow and develop normally. They should be physically active every day and their growth should be checked regularly. Older people should eat nutritious foods and keep physically active to help maintain muscle strength and a healthy weight. NHMRC, 2013a, p. 11 The following points have been adapted from Guideline 1 of the Australian Dietary Guidelines: • Being an ‘unhealthy’ weight indicates that a person is underweight, overweight or obese. • Healthy weight is associated with reduced risk of chronic disease, including cardiovascular disease, type 2 diabetes and some cancers. • People can meet their nutritional needs using the Australian Dietary Guidelines as a guide and should try to ensure that their total energy intake does not exceed their total energy expenditure. • Physical activity is an important part of a healthy, active life. • There is a high prevalence of overweight and obesity in Australia. What we eat and how much we eat really does matter. For example, eating a little too much food every day, even if it seems insignificant, does contribute to weight gain in people of any age. This is magnified if activity levels are decreased with this additional consumption of food. • It is important to achieve an appropriate suitable energy intake within suitable macronutrient distribution ranges for protein, fat and carbohydrate. Generally speaking, the quantities of food outlined in the Australian Guide to Healthy Eating and companion resources (see Figure 2.1 and

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Macronutrients Nutrients that are needed in large amounts to provide calories or energy. Nutrients are substances needed for growth, metabolism and other body functions. There are three primary macronutrients: carbohydrate, fat and protein Proteins Large molecules that make up half the dry human body weight. They are the building blocks of body tissue and can also provide the body with energy Fat A naturally occurring, oily substance that provides a major fuel source for the body Carbohydrates Large molecules consisting of carbon, hydrogen and oxygen that provide energy to the body

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http://www.eatforhealth.gov.au) should not be exceeded. Food choices that are considered high-fat, high-sugar foods are described by the Australian Dietary Guidelines as discretionary foods, since they are high in kilojoules (energy-dense) and nutrient-poor. • Weight should be measured regularly in adults so that the amount and/or quality of food, drinks and physical activity can be adjusted accordingly. Children and adolescents need sufficient nutritious foods to grow and develop normally. NHMRC, 2013a, p. 11

TIP Micronutrients Nutrients that are found naturally in plant- and animalbased foods and are required by humans and other organisms in small quantities Overweight Indicated by a BMI greater than or equal to 25kg/m2 Obesity Indicated by a BMI greater than or equal to 30kg/m2

Fruits and vegetables are a great source of micronutrients.

Overweight and obesity Overweight and obesity are associated with an increased risk of diseases such as hypertension (NHMRC, 2013a, p. 13). Being overweight can reduce life expectancy. Being underweight can also have adverse health consequences including decreased immunity (leading to increased susceptibility to some infectious diseases), osteoporosis, decreased muscle strength and hypothermia. Indeed, among older people, being underweight can be more harmful than being overweight (NHMRC, 2013a, p. 14). Currently, the most common approach used to measure a healthy weight is the body mass index (BMI). BMI is a measure of body size that compares weight (in kilograms) divided by height (in metres squared) (kg/m2) (NHMRC, 2013a, p. 13). BMI is a measure of body size that is used to provide an indication of the risk of mortality (death) or morbidity (ill health). This is a useful tool for the general population but there are limitations to BMI as it does not give information on body composition. For example, a client’s body composition may be mostly muscle and low fat but the BMI may suggest the client is obese. However, BMI continues to be used by the World Health Organization as a tool to help define overweight and obesity (WHO, 2015). Waist circumference is another measurement tool used to gain an indication of the amount of excess body fat carried by a client. Again, it is only an estimate, but it is now considered a risk factor for chronic disease and used in the Adult Pre-exercise Screening System (APSS) tool used in Australia (ESSA, 2011), which is described in detail in Chapter 3. Environmental factors that promote obesity include: • increased availability, decreased relative cost and increased marketing of discretionary foods • urban design and technology that reduces energy expenditure during daily activities and increases the reliance on cars and labour-saving devices • less physical activity (sometimes related to a reduced perception of safety and also due to more sedentary work practices) • reduced food literacy and cooking skills and greater reliance on convenience and takeaway foods (NHMRC, 2013a, p. 14). Factors associated with increased risk of overweight and obesity in adulthood include: • birth weight (increased birth weight increases the risk of overweight or obesity in childhood, adolescence and later life) (NHMRC, 2013a, p. 20) • childhood or adolescent weight gain • overweight parents • maternal smoking during pregnancy • watching TV and other media devices • being part of a low-income family • smoking during childhood • low self-esteem and/or depression • stressful family life • food insecurity (a lack of physical and economic access to sufficient, safe and nutritious food to meet dietary needs to be able to lead an active and healthy life) • self-reported dieting, especially in women (this means that the person says that they are on a diet, but they are putting on weight, most likely because they are not being completely honest about what they are eating) • inadequate sleep • low rates of breakfast consumption (NHMRC, 2013a, p. 21).

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CHAPTER 2 Nutrition People who eat breakfast tend to lead more healthy lifestyles overall than people who don’t eat breakfast.

Dietary patterns and specific foods and drinks There is increasing evidence that consumption of specific foods and food groups is associated with risk of excess weight gain (NHMRC, 2013a, p. 19). Overall, however, it is the proportion of macronutrients consumed that may be responsible for the development of obesity. Here are some important factors to consider in weight control or management. • Excess sugar (a carbohydrate): This is associated with weight gain in adults and in children. A lot of foods have added sugar, for example fruit juices that may contain 5 oranges and added sugar are easier to consume than eating 5 oranges. This can be associated with increased risk of weight gain in adults and children. • Sugar-sweetened beverages: These contribute to total energy intake. This may include soft drinks, sweetened juices and ‘sports drinks’. The high-fructose corn syrup and sucrose, which are often used to sweeten drinks, basically create a ‘liquid lolly’. The kilojoules within these drinks do not satisfy your natural hunger and so you tend to eat the same amount of solid food whether or not you drink a sweetened beverage.    Sweetened beverages also contain high amounts of carbohydrates that are rapidly absorbed, leading to a spike in blood glucose levels. This causes over-stimulation of the release of the hormone insulin, causing your blood glucose levels to drop to low levels. Stress hormones can help to bring your blood glucose levels back to normal, but you are left with feelings of hunger that make you want to eat again. This process can repeat itself several times per day for those who drink these sugar-sweetened beverages. Cola-type soft drinks contain caramel colouring, which may also increase insulin resistance and inflammation of the capillaries (your tiny blood vessels). • Vegetables and fruit: There is evidence that consumption of vegetables is associated with reduced risk of weight gain. Consuming fruit is also associated with reduced risk of obesity and weight gain. • Portion sizes: There is strong evidence to support a positive relationship between larger portion sizes and increases in body weight. • Dairy foods: Consumption of dairy foods is not generally associated with weight change or risk of obesity. It is also not associated with BMI or BMI changes in childhood. • Grains: There is evidence of a probable association between consumption of three to five serves per day of grain (cereal foods – mainly wholegrain) and a reduced risk of weight gain. • Nuts: Consuming nuts is not related to a risk of weight gain in the short term (NHMRC, 2013a, p. 20).

Weight loss in adults who are overweight According to the Australian Dietary Guidelines, weight loss will not be achieved unless energy intake is lower than energy expenditure (NHMRC, 2013a, p. 24). However, weight loss, especially long-term weight loss, is not always as simple as ‘reducing energy intake’. Some people wrongly assume that weight loss equates to eating less of everything and end up starving their body of vital nutrients for health. This can be a metabolic disaster. Lifestyle improvements reinforced through cognitive and behavioural changes help to increase physical activity and improve eating patterns that are fundamental to weight management (NHMRC, 2013a, p. 24). Dietary and physical activity patterns need to be sustainable for people to achieve long-term weight loss success. Regular weight loss of around 1–4 kg per month initially, reaching 10 per cent loss of starting weight in the medium term and 10–20 per cent loss of starting weight over one to five years, is likely to result in effective and sustained weight loss (NHMRC, 2013a, p. 24). A summary of practical guidelines is provided in Table 2.1.

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TIP

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Table 2.1 Summary of practical considerations for Guideline 1 Population group

Considerations

Adults – to achieve and maintain a healthy weight

• Nutritious foods should be chosen from the five food groups and the unsaturated fat allowance, in amounts consistent with foundation diets.* • Discretionary (energy-dense, nutrient-poor) choices should be limited. • Taller and/or more active adults in each age and sex group can choose additional serves of foods from the five food groups and/or unsaturated spreads and oils and/or discretionary foods to increase their energy intake to meet energy requirements. • Weight and waist circumference should be measured regularly (e.g. every two or three months) • The recommendations of the Australian Physical Activity and Sedentary Behaviour Guidelines should be followed.

Adults – to promote weight loss

• The foundation diets should be adhered to, without discretionary foods or any additional serves of the five food groups. • Weight loss will not be achieved unless energy intake is lower than total energy expenditure. • Behavioural change to increase physical activity and improve dietary intake is fundamental to weight management.

Infants, children and adolescents – to achieve and maintain a healthy weight

• Foundation diets represent the basis of optimum diets to support optimum growth and development. • Growth and weight should be checked regularly, and the amount and/or quality of diet and physical activity adjusted. • Childhood is a period of education about good nutrition – appropriate use of food helps to establish healthy nutrition practices for life.

Infants, children and adolescents – to manage overweight

• Restricting the diet – beyond adherence to the foundation diets and limiting intake of discretionary foods and drinks – is not recommended. • The recommendations of the Australian Physical Activity Guidelines (Department of Health, 2014) should be followed.

Pregnant and breastfeeding women

• Appropriate steady weight gain during pregnancy is important to optimise short- and long-term health outcomes for both infant and mother. • Weight-loss diets are not recommended at any time during pregnancy.

Older people

• Declining energy expenditure with age must be balanced by adjusting energy intake to maintain body weight within the healthy range. • Physical activity is needed to help maintain muscle strength. • Lowering blood pressure and normalising blood lipids may be more appropriate for overweight older people than reducing weight. • The upper range of BMI for healthy adults may be more appropriate for older persons. • The Australian Dietary Guidelines are not appropriate for frail elderly people or those with complex health conditions – an appropriate health professional should be consulted.

Australians of Asian origin

• Applying the current WHO BMI cut-off points may underestimate body fatness and comorbidity risk.

* Foundation diets provide the nutrient needs for a particular age, gender or lifestyle group, but within the energy needs of the least-active and smallest person in that group. The aim is to formulate dietary patterns that are practical, realistic and achievable and that take into account factors such as food security (availability, accessibility and affordability) (NHMRC, 2013b: 27). Source: Australian Dietary Guidelines (NHMRC, 2013a, p. 29).

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CHAPTER 2 Nutrition

Guideline 2: Enjoy a wide variety of nutritious foods Guideline 2 of the Australian Dietary Guidelines recommends the following: Enjoy a wide variety of nutritious foods from these five groups every day: • Plenty of vegetables, including different types and colours, and legumes/beans • Fruit • Grain (cereal) foods, mostly wholegrain and/or high cereal fibre varieties, such as bread, cereals, rice, pasta, noodles, polenta, couscous, oats, quinoa and barley • Lean meats and poultry, fish, eggs, tofu, nuts and seeds, and legumes/beans • Milk, yoghurt, cheese and/or their alternatives, mostly reduced fat (reduced fat milks are not suitable for children under 2 years). And drink plenty of water. NHMRC, 2013a, p. 31 Dietary patterns that include a wide variety of nutritious foods are more likely to meet nutrient requirements, promote health and wellbeing and lead to greater health benefits than restricted diets (NHMRC, 2013a, p. 31). There is increasing evidence of the role that wholefoods play in promoting health and wellbeing, and of the role of food components other than nutrients in protecting against some chronic diseases when consumed as part of a varied and nutritious diet. These non-nutrient components, which include phytochemicals, are obtained from plants and are biologically active but not directly associated with deficiency syndromes (NHMRC, 2013a, p. 33). The other benefit of dietary variety is that it can dilute the toxins that are sometimes found naturally in foods. Other ways to dilute the toxins that can be found in foods include appropriate and careful processing, cooking and storage of food (NHMRC, 2013a, p. 33) (see the section on Guideline 5 later in this chapter). A varied diet can also maximise the amount of nutrients to which you are exposed, because nutrients tend to work better when they are consumed as part of a whole diet. In other words, foods have complex relationships with each other and, when consumed together, they can ‘influence the absorption, metabolism and retention of nutrients’ (NHMRC, 2013a, p. 33). This makes a varied diet better ‘than restricted, monotonous dietary patterns’ (NHMRC, 2013a, p. 33). It’s relatively difficult to ‘overconsume’ one type of nutrient. Overconsumption problems associated with excess intake of nutrients are nearly always associated with the intake of dietary supplements. However, it is possible to develop symptoms of toxicity when dietary patterns concentrate on particular foods, or if the same nutrient is consumed in different chemical forms. For example, excessive consumption of carrot juice or liver may cause vitamin A toxicity (NHMRC, 2013a, p. 33). The word ‘plenty’ is used purposefully in the Australian Dietary Guidelines’ 2013 version of Guideline 2 ‘to encourage the increased consumption of vegetables (except those that are fried)’ (NHMRC, 2013a, p. 33). This was different from earlier versions of the Guidelines, where the focus was on the adequate amount of preferred varieties from each food group – for example, wholegrain, lean, lower-fat or plain tap water. This change was made to distinguish between eating a variety of foods and overconsumption (NHMRC, 2013a, p. 33). An outline of the considerations for consuming a wide variety of foods is shown in Table 2.2.

Water and hydration Water is essential for life. All biochemical reactions occur in water. Water fills the spaces between cells and helps to form the structures of large molecules such as protein and glycogen. Water is also required: • for digestion, absorption and transportation • as a solvent for nutrients • for elimination of waste products • to regulate body temperature (NHMRC, 2013a, p. 61).

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Phytochemicals Chemical compounds that occur naturally in plants

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

Table 2.2 Considerations in advising people from specific groups to consume a wide variety of foods Population group

Considerations

Pregnant and breastfeeding women

• Quality, nutritious dietary patterns are essential in meeting the nutrient requirements of mother and foetus within the mother’s energy requirements. • Pregnant women are at higher risk of foodborne illness. Foods associated with a risk of Listeria bacteria should be avoided. • While bread in Australia contains iodine and folate, supplementary folate is recommended pre-conception and in the first trimester, and iodine should be supplemented pre-conception and throughout pregnancy and breastfeeding. • During pregnancy, care needs to be taken with consumption of some fish species due to their high mercury content. • Nuts need only be avoided if the mother herself has an allergy to them. • The need for fluids is 750–1000 mL above regular daily needs. • A high-fibre diet and drinking sufficient water is effective in treating constipation.

Infants (less than 12 months)

• Exclusive breastfeeding is recommended for around the first six months, and should continue for 12 months and beyond for as long as the mother and child desire. • Breastmilk supplies adequate water up to around six months of age, but cooled boiled water may need to be provided from birth for formula-fed infants. • A wide variety of solid foods should be introduced from around six months, with the first foods being iron-rich (e.g. iron-fortified cereal, meat and alternatives). • The texture of solid foods should be appropriate to the infant’s level of development. • Some foods may need to be introduced many times before they are accepted. • Hard pieces of food (e.g. some raw vegetables and fruit, whole nuts) should be avoided. Nut butters or pastes do not increase the risk of allergies and can be introduced from six months. • Breastmilk or infant formula should be the main drinks in the first 12 months; however, cow’s milk may be served in small quantities as custards, with cereals or as yoghurt between six and 12 months.

Children and adolescents

• A wide variety of nutritious foods is needed to support normal growth and development. • Parents and carers can support optimal dietary patterns by modelling behaviours and purchasing and preparing nutritious foods. • Reduced-fat milk, yoghurt and cheese products are recommended for children two years and older. • Dietary restrictions are generally unsuitable for growing children and adolescents. • Suspected food intolerance or allergy should be confirmed by a medical practitioner. • Adolescents may be vulnerable to disordered eating.

Older people

• Reduced mobility, isolation, poor dentition and poverty may reduce access to nutritious foods. • Particular care is required to ensure adequate water intake; the outcomes of dehydration are serious. • People with chronic health issues and frail elderly people often have dietary requirements that are different from those of healthy, free-living older people.

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CHAPTER 2 Nutrition →

Population group

Considerations

People living in remote areas and people in lower socioeconomic groups

• Healthy food habits may be difficult to afford. • In urban areas, there may be less access to supermarket foods and greater access to fast foods. • In rural and remote areas, a wide variety of fresh foods may not be available locally or may be expensive. Available traditional foods can be a nutritious alternative. • Seasonal, frozen and canned fruit and vegetables, dried milk powder and grains and tinned fish can be nutritious, accessible options.

People with vegetarian or vegan dietary patterns

• A variety of plant foods should be chosen to ensure adequate intake of iron and zinc. • Vitamin B12 is only available from animal food sources and supplementation may be needed.

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Source: Australian Dietary Guidelines (NHMRC, 2013a, pp. 64–65).

Water is lost from the body through sweating (from 100 mL to several thousands of millilitres per day) and from the lungs (in very small amounts that are hard to measure), the skin (approximately 800 mL per day), faecal losses (approximately 200 mL per day) and urine. A minimal urine volume to excrete required waste is estimated at 500 mL per day, but this may need to be much more in older people due to declining kidney function (NHMRC, 2013a, p. 61). Most people will turn over about 4 per cent of their body weight in water per day. Factors influencing water requirements include: • ambient temperature • physical activity • body size (NHMRC, 2013a, p. 61). The estimated daily average intake of water for adult males and females are 2.6 L and 2.1 L (8–10 cups) per day, respectively. Remember that this includes all fluids, but it is preferable that the majority comes from plain water. Excess water can cause an imbalance between salt and water (called hyponatraemia), but this is rare in the general population. Self-regulation of excess water consumption generally occurs in healthy people in temperate climates (NHMRC, 2013a, p. 61).

Guideline 3: Limit intake of foods containing saturated fat, added salt, added sugar and alcohol The following recommendations are from Guideline 3 of the Australian Dietary Guidelines: • Limit intake of foods containing saturated fat, added salt, added sugars and alcohol: a Limit intake of foods high in saturated fat such as many biscuits, cakes, pastries, pies, processed meats, commercial burgers, pizza, fried foods, potato chips, crisps and other savoury snacks: –  Replace high fat foods, which contain predominantly saturated fats such as butter, cream, cooking margarine, coconut and palm oil with foods which contain predominantly polyunsaturated and monounsaturated fats such as oils, spreads, nut butters/pastes and avocado. – Low fat diets are not suitable for children under the age of two years. b Limit intake of foods and drinks containing added salt: – Read labels to choose lower sodium options among similar foods. – Do not add salt to foods in cooking or at the table. c Limit intake of foods and drinks containing added sugars such as confectionery sugar-sweetened soft drinks and cordials, fruit drinks, vitamin waters, energy and sports drinks. d If you choose to drink alcohol, limit intake. For women who are pregnant, planning to be pregnant or breastfeeding, not drinking alcohol is the safest option. NHMRC, 2013a, p. 67

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Hyponatraemia An imbalance of water and sodium in the body where there are relatively low levels of sodium

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

An outline of the considerations in advising people from specific groups to limit intake of foods containing saturated fat, added salt, added sugars and alcohol is set out in Table 2.3.

Table 2.3 Considerations in advising people from specific groups to limit intake of foods containing saturated fat, added salt, added sugars and alcohol Population group

Considerations

Pregnant and breastfeeding women

• Additional energy requirements should be met through extra foods from the five food groups rather than energy-dense discretionary foods. • Not drinking alcohol while pregnant is the safest option – there is no lower limit that can be guaranteed to be completely safe for the foetus. • Abstaining from alcohol is the safest option for women who are breastfeeding – for those who drink, expressing milk before consuming alcohol is the next best option.

Infants

• Babies who fall asleep while continuing to feed from a bottle containing infant formula, fruit juice or other sugar-containing liquid can develop a severe form of tooth decay. • When solid foods are introduced, salt and sugar should not be added to prepared food and the salt and sugar content of readymade foods should be checked.

Children and adolescents

• Introducing healthy eating patterns in early childhood influences dietary patterns in later years; however, reduced-fat milk, yoghurt and cheese products are not recommended for children under two years. • Water and plain milk are recommended drinks – consumption of soft drink, ‘sports drinks’, ‘vitamin waters’, cordials, fruit drinks and energy drinks should be limited. • Not drinking alcohol is especially important in children under 15 years of age, who are at the greatest risk of harm from drinking. • For adolescents aged 15−17 years, the safest option is to delay drinking for as long as possible.

Older people

• Older people with complex health issues or frail elderly people often have dietary requirements that are different to those of healthy, free-living older people where maintaining energy intake is a priority and discretionary foods may assist in preventing malnutrition. • Older people are more susceptible than others to the toxic effects of alcohol, and for some older adults, drinking alcohol increases the risk of falls and injuries. • Older people are advised to consult their health professionals about the most appropriate level of drinking for their health. Source: Australian Dietary Guidelines (NHMRC, 2013a, p. 85).

An extra word on salt According to Nutrition Australia (2009), adequate sodium intake is 460–920 mg per day, but Australian adults are often consuming about 3500 mg per day! High sodium levels are strongly associated with high blood pressure (hypertension). This significantly increases the risk of stroke. Nutrition Australia recommends restricting sodium intake early in life so that sodium levels remain at healthy levels. Our tastebuds have been trained to like salt, and even children are being exposed to too much salt. According to Nutrition Australia, taste buds are flexible and can adjust to less salt. General tips from Nutrition Australia for reducing salt are listed below: • Snack on fresh fruit and unsalted nuts. • Buy fresh foods as much as possible and avoid processed foods. • Read the nutrition information panel and look for foods with a sodium content no higher than 120 mg per 100 g. • Dress salads with olive oil and balsamic vinegar and avoid adding salt to dressings. • Try flavouring foods with herbs, spices and vinegars rather than salt (Nutrition Australia, 2009).

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CHAPTER 2 Nutrition

Guideline 4: Encourage, support and promote breastfeeding The following recommendations are from Guideline 4 of the Australian Dietary Guidelines: • Breast milk contains many unique compounds, including live cells, which provide all the nutritional requirements to support growth and development of infants to around 6 months of age. • Breastfeeding provides health benefits to infants including reduced risk of infection, asthma and atopic disease and sudden infant death syndrome. It contributes to improved cognitive development and protects against obesity, hypertension and some chronic diseases in later life. • Benefits to mothers from breastfeeding include improved bonding with their infant, accelerated recovery from childbirth and progress towards a healthy body weight. Breastfeeding is also associated with reduced risk of some cancers. • Infants should be exclusively breastfed until around 6 months of age when solid foods are introduced. Breastfeeding should be continued while solid foods are introduced until 12 months of age and beyond, for as long as the mother and child desire. • Breastfeeding outcomes (including initiation rates and duration) are improved where the mother has support and encouragement from the infant’s father, other family members, health workers, the hospital and the community. NHMRC, 2013a, p. 87 See Table 2.4 for considerations in encouraging, supporting and promoting breastfeeding.

Table 2.4 Considerations in encouraging, supporting and promoting breastfeeding Strategy

Considerations

Increased duration of breastfeeding

• Encourage exclusive breastfeeding until around six months of age, when solid foods are introduced. • Encourage the continuation of breastfeeding while solid foods are introduced until 12 months of age and beyond, for as long as the mother and child desire.

Antenatal education

• Information should include the benefits of breastfeeding and the risks of not breastfeeding to mothers, fathers and primary carers, as well as principles of lactation, myths, common problems and their solutions.

Hospital support of breastfeeding

• Promote the principles of the Baby Friendly Hospital Initiative, including: –– measures to encourage initiation of breastfeeding include early skin-to-skin contact, rooming-in and breastfeeding on demand –– staff should be trained in skills to support initiation of breastfeeding and resolution of any early problems –– discourage interventions that interfere with establishing lactation – e.g. the use of artificial teats or pacifiers.

Community support of breastfeeding

Seek to address breastfeeding problems in the first few weeks. Encourage mothers to seek support from community health nurses, voluntary organisations (such as Australian Breastfeeding Association helpline) and GPs. Community acceptance and support of breastfeeding should be encouraged. Source: Australian Dietary Guidelines (NHMRC, 2013a, p. 96).

Guideline 5: Food safety The following section is from Guideline 5 of the Australian Dietary Guidelines: •  Bacterial and viral food poisoning is a result of pathogenic organisms reaching harmful levels or the production of pathogenic toxins. • Incorrect handling of food and storing food at inappropriate temperatures are major causes of food poisoning. Particular care should be taken when handling food to be consumed by people who have an increased risk of foodborne illness, such as pregnant women, infants, older people and people with certain medical conditions. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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The ability of bacteria to grow in a food depends on external factors such as temperature, as well as characteristics of the food itself, such as protein content, water content and pH [acidity]. For example, bacteria are least active in very acidic foods. Most bacteria can multiply at temperatures between 5°C and 60°C but a few pathogenic bacteria multiply at or below 5°C. [Refrigeration reduces the risk of bacteria multiplication.] The method chosen for thawing food should minimise the time the food is at room temperature, where micro-organisms can multiply. Ready-to-eat frozen foods should be thawed in the refrigerator or under cold water in an airtight plastic wrapper or bag, with the water changed every 30 minutes. Many foods should be cooked to at least 75°C. A thermometer should be used to check food is properly cooked to a minimum safe temperature (roasts and meats 62°C; mince, eggs and soups 71°C; whole poultry 82°C). Not all meats need to be cooked thoroughly; steaks, whole fillets, chops and whole pieces of roast meat can be eaten rare. In contrast, rolled and/or stuffed meats, poultry, pork, sausages and mince should always be cooked through, until the juices run clear when the meat is pierced. Cooking does not guarantee safety because some bacterial spores can survive several hours of cooking and grow later in the food if there is poor temperature control. Foods such as stews and other meat and poultry dishes that will be eaten later should be cooled as quickly as possible to prevent spores from germinating and bacteria from multiplying. Foods that have been cooked and are still very hot can be cooled at room temperature until the temperature of the food drops to 60°C. The food should then be cooled to 5 degrees Celsius as quickly as possible. NHMRC, 2013a, pp. 97 & 99 The use of date-marking provides a guide on the shelf life of a food item in terms of quality and safety, as follows: • ‘Best before’ indicates the length of time a food should be kept before it starts to deteriorate. • ‘Use by’ indicates how long a food can be expected to remain safe provided it has been stored according to any stated storage conditions and the package is unopened (NHMRC, 2013a: p. 99). See Table 2.5 for considerations when providing advice on food safety to people from specific groups.

Table 2.5 Considerations in providing advice on food safety to people from specific groups Population group

Considerations

Pregnant and breastfeeding women

• Foods associated with a risk of Listeria bacteria should be avoided. • Care should be taken with foods more likely to contain mercury (e.g. certain types of fish).

Infants

• If formula-fed, care should be taken when preparing formula, including sterilising bottles and other equipment. • Pacifiers (dummies) should be sterilised. • Foods should not be reheated more than once, and any foods served but not consumed should be discarded.

Adults with illness

• Impaired immune function increases the risk of foodborne illness – prepared foods should be handled with particular care.

Older people

• High-risk foods should be cooked, dairy products pasteurised and specific foods associated with a risk of Listeria bacteria avoided. • Pre-prepared meals should be safely stored if not consumed immediately. Source: Australian Dietary Guidelines (NHMRC, 2013a, p. 100).

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CHAPTER 2 Nutrition

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2.3  WHAT IS THE SCOPE OF PRACTICE FOR AN AUSTRALIAN FITNESS INSTRUCTOR? Fitness instructors are often asked for nutritional advice from clients regarding how to lose weight, gain muscle or improve overall health. Fitness instructors are encouraged to provide basic healthy eating guidelines, specifically following the Australian Dietary Guidelines and Eat for Health’s Educator Guide. Fitness Australia, in conjunction with the Dietitians Association of Australia, has identified general eating advice, including: • the benefits of following the recommendations of the Australian Dietary Guidelines and Eat for Health Educator Guide • food groups, types and amounts of foods to be included in a healthy diet • comparing client’s general pattern of eating to the Australian Dietary Guidelines and/or Eat for Health recommendations • assisting clients to change their eating patterns using the Australian Guide to Healthy Eating • general nutritional advice for weight management that aligns with the above guidelines • providing examples of meals and snacks • encouraging the use of the above guidelines for healthy preparation and cooking • educating clients about how to read food labels for nutritional information (Fitness Australia, 2017). Fitness instructors cannot go outside the basic healthy eating guidelines discussed above, since the depth of knowledge and training that a fitness instructor receives is not adequate to provide any specific nutritional advice. A collaborative approach in conjunction with an accredited practising dietitian or accredited sports dietitian is recommended if clients are requesting: • eliminating specific foods • the use of nutritional supplements • specific nutritional advice relating to a medical condition • personalised meal plans with specific foods, amounts, timing and consumption. This collaborative approach with a dietitian reduces the risk of clients having: • nutritional deficiencies and imbalances • a detrimental impact on existing health conditions • food intolerances or allergic reactions • negative food–drug interactions • nutrition confusion. Possible consequences for fitness instructors practising outside their ccope of practice include: • legal action, which can have a financial impact from legal costs • possible complaints to Fitness Australia and resulting loss of registration • loss of reputation and impact on credibility. Note that, while there are there are some great nutrition courses available, up to and including at Diploma level, that will increase your knowledge and understanding, studying them will not extend your scope of practice to providing nutritional and dietary advice.

READING SKILLS

ORAL COMMUNICATION SKILLS

2.4  A BALANCED DIET Each gram of food you eat can provide a certain amount of energy as kilojoules (kJ). Take a look at Table 2.6 to see how much this amount can vary for different types of nutrients.

Table 2.6 Kilojoules provided by nutrient Nutrient

Kilojoules provided by one gram

Fat

37

Protein

17

Carbohydrate

16

Alcohol

29

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Kilojoules (kJ) Units of energy that are used for measuring the energy value of food

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Calories (cal) Units of energy that are also used to measure the energy value of food. 4.1868 kilojoules = 1 calorie Kilocalories (kcal) Units of energy that are also used for measuring the energy value of food. 1 kilocalorie = 1000 grams of calories Preservatives Chemical compounds that are added to food to preserve it from decaying or decomposing Food additives Chemicals that are added to foods to enhance their colour, flavour or texture

PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

The term calorie (cal) is also often used to measure energy – this can be confusing at times, because kilojoules and calories have different energy-burning values. The term kilocalorie (kcal) is sometimes used, too. Here is the conversion rate you need to use to change from kilojoules to calories when you are examining the energy values of food: 4.1868 kJ = 1 cal

Preservatives and food additives Food manufacturers add chemicals to foods to enhance their colour, flavour, texture or shelf life. These additives are listed in descending order of weight in the ingredients list of a packaged food. Preservatives and other food additives have a ‘number’ allocated to them. For example, monosodium  glutamate, a flavour enhancer better known as MSG, is numbered 621. While food additives undergo testing before being exposed to the marketplace, most of them are tested in isolation, and so the long-term effects of combining different food additives in the diet require further research. One thing that is becoming quite apparent is that some people are more sensitive to experiencing adverse reactions to food additives (such as MSG) than others, with some of the most common reactions tending to happen in young children. Examples of adverse reactions include insomnia, irritability, behaviour disturbances and rashes. Not all processed foods contain food additives. An example of this is long-life milk. Check packaged food labels for hidden food additives, remembering that some ingredients in an ingredients list may also have food additives within them (e.g. margarine) that have not been mentioned.

The importance of breakfast It is common in the western world to say, ‘Breakfast is the most important meal of the day.’ This notion is based on the fact that the body has been ‘fasting’ through the night as it recuperates from the previous day’s activities and prepares for the next day. The time spent fasting results in the metabolism slowing down to conserve energy. Many fitness enthusiasts have advocated the importance of breakfast because of a belief that it kick-starts metabolism and helps people lose weight. Many of the assumptions about the importance of eating breakfast are based on cross-sectional studies, which have observed that eating breakfast is associated with reduced risk of weight gain and certain chronic diseases, such as diabetes and cardiovascular disease. However, past research that resulted in this assumption did not take into account that people who eat breakfast also tend to: • be more physically active • eat less fat • be non-smokers • not overconsume alcohol.

TIP Epidemiology The study of the distribution and determinants of health-related states, events or diseases

Epidemiology has consistently associated infrequent breakfast consumption with increased risk of: • adiposity (being overweight or obese) • diabetes • cardiovascular disease (Betts et al., 2014). So the focus should really be on whether eating breakfast makes you healthy or whether healthy people are more likely to eat breakfast. To address this question, a study was carried out by researchers from the University of Bath and published in the peer-reviewed American Journal of Clinical Nutrition (Betts et al., 2014). The study involved a six-week trial in which two groups of 38 people were randomly assigned to one of two groups: one that was to eat breakfast, and one that was to have an extended morning fast until noon, drinking only water. The groups were balanced fairly regarding normal and overweight participants and the distribution of participants who frequently and infrequently ate breakfast.

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CHAPTER 2 Nutrition The researchers found that the participants who ate breakfast generated significantly more heat during physical activity performed before noon compared to participants from the fasting group. The group that ate breakfast also engaged in more physical activity, particularly ‘light’ physical activity. The resting metabolic rate was stable among participants in both groups, which ran contrary to the results expected by those who believe that breakfast is needed to enhance resting metabolism. There was no resulting suppression of appetite in the group that ate breakfast either (whose energy intake remained 539 kcal per day greater than the fasting group throughout the day). Interestingly, there was also no other difference between the groups in fasting blood-sugar or insulin levels at six weeks; but during the last week of the trial (when continuous sugar monitoring occurred), the fasting group demonstrated more variability in their afternoon and evening blood-sugar levels. The researchers concluded that: • daily breakfast is causally linked to higher physical-activity heat generation (thermogenesis) in lean adults, and to greater overall dietary energy intake (basically, you will burn more energy during exercise when you are a breakfast-eater) • there is no change in resting metabolism resulting from being a regular breakfast-eater. The major limitations of this study were: • the small sample size • difficulty knowing if all the participants actually complied with the guidelines of their group • that the study only lasted for six weeks, and so produced no long-term results. Basically, this study does not completely settle the debate on whether or not breakfast is the most important meal of the day. However, it is true that breakfast-eaters tend to be slimmer and healthier individuals because they generally follow healthier lifestyle practices, such as eating a balanced diet and participating in physical exercise (Reeves, Halsey, McMeel & Huber 2013). Some people simply do not enjoy eating breakfast and prefer to eat later in the day. This may not be a problem; however, these individuals need to be careful that they have sufficient energy to carry out their daily tasks. For these people, a smaller meal or a nutritious liquid meal may be an alternative until their appetite increases later in the morning.

How many meals per day? There is not a ‘magic number’ of meals that should be consumed per day. However, people are increasingly encouraged to spread their kilojoule/energy intake throughout the day. This may include, for some people, having five smaller meals rather than three large meals, while others prefer to stick to three meals per day. Some people have also been led to believe that it is best to avoid certain foods after certain times of the day – say, 4 p.m. To date, this is not based on any conclusive scientific research. If people are eating their main meal at the end of the day, it is quite likely that the bulk of the kilojoules they consume are at dinner. It may be wise to spread this out during the day so that the body is not required to digest so much food all at once, especially at night, when the body will be sleeping and trying to recuperate from the day. Portion control is an important aspect of healthy eating.

When a weight-loss attitude is unhealthy If consumption of kilojoules outweighs the energy spent during the day through physical activity, it is logical that it will be difficult to lose weight. Unfortunately, some people try the unhealthy method of severely restricting kilojoule intake, which can have poor health consequences. Being ‘skinny’ as a result of consuming too few kilojoules can actually result in your body being ‘metabolically unhealthy’. When there is not enough energy to fuel the body, the body will look to break down its own muscle as a fuel source. This is not good!

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Anorexia nervosa A life-threatening mental illness and eating disorder associated with severe food restriction and weight loss. It causes physical problems such as weakened bones (osteoporosis), slowed growth and infertility, as well as a wealth of mental, social and emotional problems Bulimia nervosa A severe mental illness and eating disorder whereby the person regularly binge-eats and follows this with forced vomiting or excessive exercise to compensate

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PART 1: INTRODUCTION TO THE HUMAN BODY AND HEALTHY EATING

Severe kilojoule restriction can reduce metabolic rate and can actually cause long-term weight gain once normal eating habits resume. The desire to lose weight rapidly can sometimes lead clients to severely restrict their kilojoule intake, especially if they have a distorted body image. This can lead to the development of diseases such as anorexia nervosa and bulimia nervosa. A cycle of weight loss and weight gain that continues for extended periods of time is often referred to as yo-yo dieting. Identification of behaviours that aid or hinder weight-control efforts is an ongoing priority for fitness instructors and their clients. Weight monitoring, especially self-weighing behaviours, and how this relates to psychological constructs like body image, are poorly understood. One study (Klos, Esser & Kessler, 2012) of body image highlighted that more frequent self-weighing among women was associated with: • a greater orientation towards appearance • a preoccupation with being overweight • concern with body shape. More frequent self-weighing among men was associated with: • greater body-area satisfaction • greater orientation towards health and fitness • positive health evaluation. The results of this study suggested that self-weighing is a fairly common behaviour, but that its relationship with body image is complex and can vary based on gender. Fitness Australia has created for fitness instructors a series of guidelines on eating disorders, which provide the policy statements, summarised as follows: • As a preventative approach, an ‘activity assessment form may assist fitness instructors if they suspect a client is training excessively or developing an eating disorder. • A part of the recovery process for clients with eating disorders is the right to continue exercising at appropriate levels of exercise. • If a client has a BMI lower than 14, they should not be exercising and should be referred to their GP. • If a client discloses that they are binge-eating, purging or abusing diet pills or laxatives, they should stop exercising and be referred to appropriate services. • The activity statement can be useful to modify training if a client is training excessively, which can lead to injury and illnesses. • Specialist intervention is required to assist clients with possible eating disorders. It is recommended to use the ‘activity approval form’ and a GP referral and reviewing the client’s program. • Correct treatment advice can assist clients with eating disorders, and fitness instructors are encouraged to provide support to such clients. • Club management reserves the right to suspend a membership or restrict the use of the club where there is concern for the client’s physical or medical condition. Adapted from Fitness Australia, 2017 1 You have a client who has disclosed that they are binge-eating and purging. The client asks you to design a specialised diet so that they can change this behaviour. Outline the steps you would follow to manage this client while remaining within your scope of practice. 2 You are currently training a client at 6:00 a.m. He does not eat before training, but has been told that he should eat breakfast before training, even though he would prefer to eat afterwards. Is this affecting his training? 3 Visit your local supermarket, or your own pantry, and look for 10 packaged items. Make a list of all the food additives that you find. a Research some of the potential hypersensitive reactions that may be experienced from consumption of such additives. b List at least two food options healthier than the packaged and processed items you found.

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2.5  BALANCED NUTRITION Food is used as a fuel for energy in the body, and it can keep the body alive and healthy. But some foods can do the opposite and cause illness and even death. Nutrients – carbohydrates, protein, fat, minerals and vitamins – promote growth, maintenance and repair of the body. To ensure that you get enough nutrients, food intake should encompass a variety of foods – namely, breads and cereals, fruit and vegetables, meat and meat products, milk and milk products, and fats and oils. Nutrients never work alone; you need the right combination of them to ensure your body works optimally. The NHMRC has prepared Nutrient Reference Values (NRVs) for Australia and New Zealand. Recommended dietary intakes, which were used in the past, still exist, but are now part of the NRVs, which cover a wider range of nutrients (33 compared to the 19 covered by the RDIs) (NHMRC/Ministry of Health, nd.). They include a range of values for each nutrient and recommendations to help reduce the risk of chronic disease. The NRVs are made up of the following: 1 Estimated average requirement (EAR) – the amount of nutrient estimated to meet the needs of half the population of a certain age or gender 2 Recommended dietary intake (RDI) – the average amount required to meet the needs of nearly all healthy individuals of a certain age or gender; derived from EARs 3 Adequate intakes (AI) – used when there is inconsistent data to determine an EAR and RDI 4 Upper level of intake (UL) – regular intake above this level may place an individual at risk of adverse effects from excessive nutrient intake. The National Health and Medical Research Council has developed suggested dietary targets (SDTs) for nutrients to reduce the risk of chronic disease. The first three NRVs in the list above are aimed at avoiding deficiency diseases, while the SDTs are aimed at reducing the risk of chronic disease. NRVs can be broken down into further detail, but fitness instructors don’t need to go into that level of detail. Further information on NRVs can be found on the NHMRC website (http://www.nhmrc.gov.au) and the Dietitians Australia website (http://www.daa.asn.au). A simpler method of achieving balanced nutrition involves eating recommended quantities of foods from the five food groups, as we have discussed earlier in this chapter.

Nutrient Reference Values (NRVs) A set of recommendations for food intake based on scientific research

How many serves should we eat? The Australian Dietary Guidelines inform people of different ages, life stages and genders about the minimum number of serves from each food group that are required each day. It is recommended that people who are trying to lose weight stick to a minimum number of serves. However, people who are pregnant, taller or exercise regularly may require an increased number of serves. Choose to eat mostly lean meat or meat alternatives, vegetables, fruit, grains and cereals complemented by some dairy products, such as milk, yoghurt, cheese and/or a dairy alternative. Use unsaturated fats, oils and spreads sparingly. Discretionary choices can be an enjoyable part of a healthy diet occasionally; however, in most instances, it is best to swap discretionary choices for healthier options – for example, choose fruit over ice-cream for dessert. According to the Australian Government’s Eat for Health website (http://www.eatforhealth.gov.au), in order to get enough serves from all the five food groups people often find that they need to: • swap discretionary choices for foods from the five food groups • make breads or grains part of at least two meals most days • include vegetables at least twice a day (this is particularly important if you would like to lose weight) • make vegetables take up at least one-third of meals, or half the meal if you are trying to lose weight. Serving vegetables or salad as a side dish even when eating meals like pasta, lasagne or risotto can help to achieve this. By eating more vegetables in your meals, serves of other foods will be smaller and the overall meal will have fewer kilojoules • include lean meat or meat alternatives as part of at least one meal a day • add fruit to at least two meals per day, or eat fruit as snacks or desserts Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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• include a serve of low-fat milk, yoghurt or cheese as a significant part of at least two meals or snacks. It’s also good for your health to include: • fish meals every week • meals with legumes every week • a wide variety of different-coloured vegetables every day (NHMRC, 2013a).

Macronutrients The three primary macronutrients are carbohydrates, fats and proteins. The following sections will outline these macronutrients in more detail.

Carbohydrates Carbohydrates are part of food and are the body’s preferred fuel source. Fats and proteins can also be used for energy by the body. Most carbohydrates consumed come from plants, although a small amount can come from meat and from lactose (milk sugar). Carbohydrates  come in many forms: monosaccharides (a single sugar molecule) and disaccharides (two sugar molecules joined together) from fruits, sugar cane, honey and milk; and polysaccharides (long chains of sugar molecules joined together) from grains, legumes and root vegetables. Starches are polysaccharides, and can be found in foods like potato and pasta. For energy, the body relies heavily on glucose, which is a monosaccharide. Other forms of carbohydrate can be converted to glucose to be used by the body. Glucose is a major fuel source for the body, responsible for making ATP (see Chapter 1). The nervous system, in particular, relies very heavily on glucose and cannot survive for very long during periods of carbohydrate deficit. When too little carbohydrate is consumed – say, less than 50 g per day – the body starts to break down fat and protein to make energy.

Fibre Fibre The indigestible part of a plant. It is required for regular bowel movements

Resistant starch A part of plant foods that resists digestion, and therefore acts somewhat like fibre in raising bloodglucose levels more slowly

Fibre is also a polysaccharide, found in most vegetables. Human digestive enzymes cannot break down fibre, so fibre does not change its form on its way to the large intestine. In the large intestine, bacteria begin to ferment and break down the fibres. Fibre is used to facilitate defecation. It can help to prevent: • bowel cancer • constipation • haemorrhoids • diverticular disease (a type of bowel disease). Fibre can be divided into soluble and insoluble fibre; the body requires both for good health. Soluble fibre can help to lower LDL (‘bad’) cholesterol (discussed in more detail later in this chapter) and slow down stomach emptying, which helps people to feel fuller after a meal, and for longer. Soluble fibre is found in: • oats • dried beans and lentils • fruits and vegetables. Insoluble fibre is very filling, and also has a laxative effect because it absorbs water to help soften the stools to keep your bowel emptying regular. It is found in: • nuts and seeds • high-fibre breads and cereals • the skin of fruits and vegetables. Resistant starch is the part of starchy food that resists digestion in the small intestine, but is converted into other substances in the large intestine to help keep the bowel lining healthy, minimising the risk of some cancers. Sometimes starch is considered to act like a third type of fibre. It is found in: • breads and cereals containing Hi-maize™ • underripe bananas • cooked and cooled potato • slightly undercooked (al dente) pasta. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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Carbohydrates and exercise Carbohydrates are essential for achieving optimal exercise capacity. A high-carbohydrate diet provides the largest stores of muscle glycogen. Without carbohydrates, training to maximum capacity cannot occur because carbohydrates provide fuel that is crucial for muscle contraction and brain function. Glucose and glycogen are the two forms of sugar that your body uses for energy. Glucose is the sugar your body uses as an immediate fuel source (and is also the only fuel for the brain) to make energy. Glycogen is the stored form of glucose, which is stored in the muscle and liver for later use. The carbohydrates you eat are stored in the muscles and the liver, while a small amount (approximately one teaspoon) travels around in the blood. Your muscles rely on glucose and glycogen for energy when exercising at high intensity. The body can use fat for energy at lower intensities, but it takes a lot longer for the body to provide the fuel from fat compared to glucose or glycogen. The body can fully deplete its carbohydrate stores within about two to three hours of strenuous exercise – this is often known as ‘hitting the wall’. Rapid declines in blood-glucose levels can cause disorientation and unconsciousness. Consumption of food will lead to the breakdown of carbohydrates and some protein in the body to glucose. The body is always aiming to maintain its blood-glucose levels; when blood glucose levels are too high, the pancreas releases the hormone insulin to convert some of that glucose back to glycogen so that it can be stored. When blood-glucose levels are low (e.g. after strenuous exercise), the pancreas releases the hormone glucagon, stimulating the liver to convert glycogen to glucose. Muscle glycogen is used directly by muscle, rather than being converted back to blood glucose. Slowly digested and absorbed foods include: • some types of pasta • whole grains • some varieties of rice • lentils • chickpeas • couscous • bread made with softened, whole grains.

Glucose A type of sugar that the body uses for energy Glycogen A form of glucose that the body stores in the muscles and liver

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Your liver has enough glycogen reserves for only up to three to four hours of normal activity. When glycogen reserves are full (the liver can store about 90–110 g of glycogen), any extra blood glucose begins to be converted to fat by your liver. This fat can be used as a fuel source when the liver’s glycogen stores return to low levels again. Athletes can increase their stores of glycogen by regularly consuming carbohydrates. This is particularly important for people who exercise strenuously for more than 60–90 minutes per day. Athletes with special dietary requirements or questions should be referred to an accredited sports dietitian. Energy from macronutrients varies: carbohydrates provide 17 kJ/g, fat provides 37 kJ/g and protein provides 17 kJ/g.

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Fats The body requires some fat to maintain health. Some fats are healthy fats, providing the body with fat-soluble vitamins and essential fatty acids. Other fats can interfere with bodily functions and contribute to disease risk.

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Essential fatty acids Fatty acids that must be consumed in the diet because the body cannot store them

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Fat is higher in energy (kilojoules) than any other nutrient, so you only have to eat a small amount of it to gain lots of kilojoules relative to other nutrients. All fat can contribute to weight gain. Fat can be ingested in the form of saturated fats and unsaturated fats. Fats are broken down into fatty acids and monoglycerides. These are then transported in the lymph system in the form of triglycerides. Triglycerides are a type of fat that circulates in the blood, and which can be increased by alcohol consumption and sugar intake from food and drinks.

TIP Saturated fats Can be found in animal products such as meat and dairy foods. These fats have fatty-acid chains that cannot incorporate any additional hydrogen atoms. Diets high in saturated fat are associated with the development of heart disease and high cholesterol levels Unsaturated fats Have many health benefits, including contributing to the prevention of heart disease and lowering cholesterol levels. They have more than one double-bond in the fatty-acid chain Triglycerides The fat circulating in the blood Monounsaturated fats Fat molecules that can help reduce ‘bad cholesterol’ levels in your blood, which can help reduce the risk of heart disease and stroke. They are found in olive oil, avocados and many nuts and seeds

TIP Polyunsaturated fats Fat molecules that can help reduce ‘bad cholesterol’ in your blood and the risk of heart disease and stroke. They are found in fatty fish, such as salmon, as well as walnuts, tofu and soybeans

There are two types of unsaturated fats: monounsaturated fats and polyunsaturated fats. Cholesterol is a type of fat that is required for many metabolic processes. It is made predominantly by the liver, with the rest coming from the diet. It is not used for energy, but rather as a component of cell membranes. Cholesterol makes hormones like oestrogen, testosterone and adrenal hormones, and is lost from the body in the faeces. Triglycerides and cholesterol are insoluble in water, and therefore need a transport mechanism to circulate in the blood. They are transported in bodily fluids bound to small lipid-protein complexes called lipoproteins. Lipoproteins come in different densities, and so have different names: high-density lipoproteins (HDLs), low-density lipoproteins (LDLs) and very low-density lipoproteins (VLDLs). HDLs are known as ‘good cholesterol’ because they are associated with better health and less risk of heart and other health problems. LDLs are known as ‘bad cholesterol’ because they are associated with higher risk of ill health. LDLs transport cholesterol to the peripheral tissues and also regulate the production of cholesterol. HDLs transport cholesterol from the peripheral tissues to the liver to be broken down; therefore, high levels of HDL, rather than LDL, are favourable. High LDL levels are unfavourable because cholesterol deposits can start to accumulate in the artery walls. While some researchers continue to favour the link between saturated fat and disease, other researchers are supporting the view that such evidence is limited at best. Further research in this area is required. Physical activity plays an important role in keeping cholesterol levels healthy. Cholesterol is found naturally in egg yolk and meats. Trans fats are unsaturated fats that behave like saturated fats because they have been processed. They are considered to be very unhealthy and are particularly linked to an increased risk of heart attack, increased levels of LDLs and decreased levels of HDLs. Some vitamins (A and D) are classified as fat-soluble vitamins because they rely on fat to function properly. In addition, fat is required as an essential component of the protective barrier of the nervous system and all cell membranes. Subcutaneous fat in the adipose tissue can insulate and protect the body and also serve as a fuel reserve. Two of the major fat-storing sites on the human body are the thighs and the abdomen –sources of anguish for many people! Interestingly, however, the fat stored around the hips and thighs tends to be mostly subcutaneous fat, while fat stored around the abdomen is often mostly visceral fat (in and around body organs). It is this visceral fat that has a greater association with the development of disease, compared to subcutaneous fat. Saturated fats are solid at room temperature and are found in: • animal-based products such as butter, cream, full-fat milk and cheese • some plant-based foods, such as palm oil, cooking margarine, coconut and coconut milk and cream • packaged and manufactured treats such as fatty snack foods, deep-fried take-away foods, pastries and pies, cakes and biscuits. Unsaturated fats can be found in seeds, nuts and some oils. Polyunsaturated fats can be found in: • fish, which contain omega-3 fats • some oils, such as safflower and soybean oil • some nuts (e.g. brazil nuts). Monounsaturated fats are found in: • olive oil • avocados • some nuts (e.g. cashews and almonds). Trans fats are found in processed foods such as biscuits, cakes, butter and some margarines. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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Choosing foods with healthy fats 1 Use liquid plant oils for cooking and baking. These types of oils are rich in heart-healthy unsaturated fats. Olive-oil-based salad dressings are a great first step. 2 Get rid of trans fats in your diet. The label will sometimes include the amount of trans fats in the food – look for zero! Another way to check for trans fats is to check the ingredient list to look for partially hydrogenated oils. Basically, stay away from fried foods, biscuits and other baked goods. 3 Avoid butter. Butter contains trans fats. Some authorities recommend switching to soft-tub margarine; however, it is even healthier to use a liquid plant oil, such as olive oil, where possible. Avocado can also be a great, natural alternative spread. 4 Eat at least one good source of omega-3 fats per day. Fatty fish (such as salmon and tuna), walnuts and canola oil provide omega-3 fatty acids, which are essential for good health. Omega-3 fats, especially those from fish, are beneficial to the heart. 5 Cut back on red meat, cheese, milk and ice-cream. Remember that low-fat cheeses are not really low in fat compared to a lot of other foods. They can also be higher in sodium than regular cheese. Enjoy cheese in small amounts.

Protein Proteins are important for the structural makeup of the body, such as the skin, hair, nails, connective tissue and muscle, and also provide the body with energy. Proteins are naturally occurring compounds organised in a linear chain and folded in a globular formation. Protein is found naturally in many foods, but it is best to choose protein-rich foods that are low in saturated fats. Protein breaks down into smaller substances called amino acids. Once the liver has taken its full share of amino acids from digestion, the remaining amino acids circulate to the body’s cells. Cells need amino acids for: • making new proteins in the body – for example, making new skin cells as the dead ones are removed from the skin surface • about 10 per cent of the body’s energy requirements • making other compounds, such as neurotransmitters for nerve-signal transmission and hormones such as adrenalin. The body’s cells require all the amino acids (about 20) to be present for them to be of any use. Eight of these amino acids cannot be made within the body, and therefore it is crucial to obtain these from the diet. These amino acids are called essential amino acids, while the ones the body can produce are called non-essential amino acids. A protein can consist of between 50 to tens of thousands of amino acids all linked together. Protein can be used as a fuel source when inadequate levels of carbohydrate and fat are available. When necessary, the amino acids can have their amine groups removed as ammonia and the rest of the molecule will enter the aerobic energy system. Ammonia is toxic to the cells, and so it will combine with carbon dioxide to form urea, which is expelled in urine. Animal products such as meat, eggs and milk provide lots of protein. Protein from these sources is the most easily absorbed by the body. Protein can be consumed from other sources, such as legumes, nuts and cereals; however, the protein in animal products is easier for the body to use than protein from plant sources. Vegetarians must be particularly careful to ensure that they receive adequate levels of protein in their diets. A combination of cereal grains and legumes is often consumed as a way of providing the body with all the essential amino acids. It is best to consume protein-rich foods that have minimal saturated fats (e.g. choose lean meats).

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Cholesterol A type of fat made predominantly by the liver, with the rest coming from the diet. It is not used for energy but rather as a component of cell membranes Lipoproteins Small lipid-protein complexes that come in different densities, and therefore have different names. They are found in bodily fluids High-density lipoproteins (HDLs) Proteins responsible for transporting cholesterol from the peripheral tissues to the liver to be broken down. They are also known as ‘good cholesterol’ Low-density lipoproteins (LDLs) Proteins responsible for transporting cholesterol to the peripheral tissues and regulating the production of cholesterol. They are also known as ‘bad cholesterol’ Very low-density lipoproteins (VLDLs) The extra-small version of lowdensity lipoproteins (LDLs) Trans fats Unsaturated fats that behave like saturated fats because they have been processed Essential amino acids Required by the liver and cells. They are the eight amino acids that cannot be made within the body and must be obtained from the diet Non-essential amino acids Part of the amino acids group required for body functioning; however, unlike the essential amino acids, they can be produced by the body

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Protein requirements in the body depend on your weight, age and health. Sources of dietary protein include: • meat, poultry and fish • eggs • dairy products • seeds and nuts • beans and lentils • soy products • grains, such as wheat, rice, barley and corn. Animal products contain all the essential amino acids, whereas plant proteins are usually lacking at least one amino acid.

Micronutrients The two groups of micronutrients are minerals and vitamins; these will be discussed in further detail in the following sections.

Minerals

Trace minerals Minerals that are required by the body in extremely small amounts

Minerals are only required in small amounts compared to carbohydrates, fats and proteins. Minerals are not used as a fuel source, but rather work with other nutrients to keep the body functioning properly. Examples of minerals include iron, calcium, chlorine, potassium, sodium, sulphur, zinc and phosphorus. Minerals that are required in extremely small amounts are called trace minerals, some of which include chromium, silicon, tin, iodine, fluorine, manganese, nickel, cobalt and cadmium. Generally, minerals are needed for: • regulation of cell metabolism • cell growth and repair • nerve and muscle function. In order to take in adequate levels of minerals, foods such as meat, milk, vegetables and legumes should be consumed. However, the mineral content of foods can also be affected by the soil in which the food grew, the manner of cooking and the age of the food. Fatty and refined foods usually have few, if any, minerals in them. The availability of minerals in food can be affected by disease, an unbalanced diet and taking mineral supplements. The most common mineral deficiencies suffered in Australia are low calcium, leading to osteoporosis, and low iron, leading to anaemia. However, taking too many supplements can also adversely affect the balance of minerals in the body. Some major minerals are discussed below.

Calcium Most of the calcium in your body is built into your bones and teeth. The rest is found in the tissues and the blood. Calcium absorption requires vitamin D. Calcium plays a part in many vital functions in the body, including conduction of nerve impulses, muscle contraction and relaxation, heart function, blood clotting and enzyme function. Lack of calcium causes your body to take what it needs from your bones for other functions, weakening the bones. An overall lack of calcium in the body can eventually result in osteoporosis. Clients with osteoporosis are at increased risk of bone fracture and other injuries. It is a lot easier to be lacking in calcium than to overdose because any unwanted calcium is excreted by the body. Good sources of calcium include dairy products and leafy greens. Fish, nuts and seeds can also contribute to dietary calcium intake. Substances in some foods, such as chocolate, coffee and spinach, can actually make calcium unavailable to the body. Calcium needs vary during life. Babies and young children need adequate calcium intake for growth and development, and their needs generally continue to increase as they get older, especially if they are physically active. Adequate calcium intake, as well as weight-bearing physical activity and

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CHAPTER 2 Nutrition resistance exercise, are linked to higher peak bone masses than insufficient calcium intake and little or no weight-bearing physical activity or resistance exercise. Peak bone mass is generally acquired by about the mid-20s; after this time, efforts should be made to maintain bone mass. Pregnancy is also a period requiring increased calcium intake under the guidance of a doctor because the developing baby and placenta will take calcium from the mother. The skeleton is also at risk of losing calcium during and after menopause, when there is a drop in the level of the female hormone oestrogen – adequate oestrogen levels are required for maintenance of bone strength. Calcium is found in dairy products and leafy green foods. An increase in bone mass is achieved by increasing calcium intake with weight bearing exercise and resistance training.

• • • • • • •

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Overall bone strength can be affected by: low levels of vitamin D very high fibre levels very low body weight a high-salt diet drinking more than six caffeine drinks per day excessive alcohol intake low physical-activity levels.

Phosphorus Phosphorus is an essential mineral that is usually found in nature combined with oxygen to form phosphate. Most of the phosphorus in your body is part of your skeleton. The ATP molecule (discussed in Chapter 1) is essential for energy and contains three molecules of phosphate. Phosphorus is also involved in the process of making new muscle glycogen, as well as converting this glycogen to energy. Phosphorus is absolutely essential to muscle contractions because it reduces muscle acidity. Phosphorus can be obtained from meat, fish, whole grains and dairy products.

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Potassium Potassium is essential to the conduction of nerve impulses. We need more potassium than sodium, yet many foods, such as canned tuna, contain as much as three to four times more sodium than potassium. High-fat diets can block potassium absorption. Exercise can dramatically reduce potassium levels through sweating. Potassium is also lost in the urine. Potassium is found in fruits and vegetables.

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Sodium and chloride Salt is the chemical compound made of sodium and chloride. It is commonly used to preserve and flavour foods. Salt is needed for good health and for the conduction of nerve impulses and maintenance of the correct volume of circulating blood and tissue fluids. It is the main source of sodium in the human diet. Excessive sodium can cause hypertension. Most people do not need to add salt to their diet because there is already plenty in the foods they consume. Many foods today are already high in salt, so adding table or cooking salt to your food just adds to the problem. A high-salt diet places strain on the kidneys because this is the site in the body where sodium levels are regulated. High salt intake can lead to high blood pressure and other health concerns. Low sodium levels in the body are very rare, but are very dangerous when they do occur.

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Magnesium Magnesium can be found in your bones and is also essential for energy processes. When your body is short of magnesium, it will take magnesium from your bones, which makes bones more brittle.

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Magnesium can be found in whole grains, legumes and green vegetables.

Iron Iron is the essential mineral in haemoglobin. Haemoglobin is found in blood and is the component of blood responsible for binding and transporting oxygen within the blood. There are two types of iron found in the diet: haem and non-haem iron.

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Haem iron is found in animal foods and is more readily absorbed by the body than non-haem iron, which is found in plant foods. Iron is found naturally in foods such as wholegrain cereals, meat, poultry and fish. Clients who do not consume meat will often need to try to consume more iron in the form of nuts, beans, peas and dark-green leafy vegetables like spinach.

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Iron is found in liver, meat, nuts, seafood, dark-green leafy vegetables, tofu, wholegrain bread and wheat germ. Vitamin C, which is abundant in brightly coloured fruits and vegetables, is necessary for the absorption of iron in the body. Only about 10 per cent of even the best haem iron from meat sources is absorbed by the body. Absorption from non-haem iron sources, such as vegetables, can be as low as one per cent. Iron absorption can also be affected by caffeine consumption, especially at mealtimes. Haemoglobin production relies heavily on your body’s use of iron. Athletes and women experiencing menstruation are at risk of lacking iron. Refer these clients to an accredited sports dietitian or GP for nutritional advice.

Vitamins

Free radicals Molecular fragments that inflict damage to the integrity of important cellular molecules such as the protein, fat, carbohydrate and special acids of the cell

Vitamins, like minerals, do not produce energy directly. Carbohydrates, fats and proteins are the primary fuel sources for the body, but the process of making energy does require adequate vitamin intake. Vitamins are vital to the functioning of the body. For example, you only require a few micrograms of vitamin B12, but if you lack the appropriate levels of this vitamin you will immediately feel tired and will not be able to make healthy red blood cells. Lack of vitamin B12 can lead to many health problems including pernicious anaemia (a severe form of anaemia), and can eventually lead to brain degeneration, psychosis and death. Vitamins A, C and E are known as antioxidants that can attack tissue-damaging free radicals. Many vitamin supplements aim to prevent deficiency in the diet, but keep in mind that it is a combination of vitamins and minerals that usually results in the best outcome in the body, rather than an isolated vitamin or mineral. Refer all clients with questions about supplements to their GP or an accredited dietitian for advice. Fitness instructors must never prescribe a supplement to a client. Vitamins can be described as either water-soluble or fat-soluble. The body stores fat-soluble vitamins, so it is easy for high intakes of these vitamins to adversely affect the body and, in some cases, lead to toxicity. This does not usually happen through eating a well-balanced diet, but tends to happen more easily if vitamin supplements are used. The body does not store water-soluble vitamins, making toxicity less likely. The body needs continual replacement of these vitamins through a nutritious, balanced diet. However, current research recommends that folate supplements be consumed by those considering pregnancy to help reduce the risk of neural-tube defects such as spina bifida. Fat-soluble vitamins include A, D, E and K. Water-soluble vitamins include B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B12 (cobalamin), folate or folic acid, biotin, and C.

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Vitamin A Vitamin A is fat-soluble, meaning it relies on fat to be of any use to the body. It is essential for vision, growth, reproduction, immune function, skin and mucus membranes. The best food sources of vitamin A contain the preformed vitamin A substances, such as retinol, alpha- and beta-carotene. Just like most things, overdose of vitamin A can be toxic. Food sources that may be converted to vitamin A include: • liver (containing retinol) • fish liver oils (containing retinol) • egg yolk (containing retinol) • fruits and vegetables (containing alpha- and beta-carotene).

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Vitamin B1 thiamin Thiamin is water-soluble, which makes it enter and leave your body within about 24 hours. It is very important for energy production. Food sources of thiamin include fresh and raw whole grains, peas and beans.

Vitamin B2 riboflavin Riboflavin is essential for the mitochondria to make ATP. Even moderate exercise can cause a dramatic increase in the demand for riboflavin. Riboflavin can be found in dairy products, meat and fish.

Vitamin B3 niacin Niacin is water-soluble and therefore must be eaten daily. Niacin is converted to co-enzymes in the body, which are essential for energy processes. Meats, fish and poultry are the best food sources of niacin.

Vitamin B6 pyridoxine Pyridoxine is important for muscle growth and repair. Food sources of pyridoxine include fish, chicken, eggs and wheat germ.

Vitamin B12 cobalamin Vitamin B12 is essential for blood cell production and therefore for oxygen transport. It is also involved in lowering homocysteine levels in the body. Homocysteine is an amino acid that occurs naturally in the body as a result of metabolism of another amino acid called methionine. High homocysteine levels are associated with consumption and digestion of protein-rich foods and low levels of vitamin B12. Homocysteine is a waste product of cellular metabolism, and high levels of it correlate with the development of heart disease. Vitamin B12 can be found in meat, eggs and milk. Fruits and vegetables do not contain vitamin B12.

Homocysteine An amino acid found in the blood. It can damage the heart, joints and brain – the higher the levels of homocysteine, the higher the risk of disease

Folate Folate is essential for amino acid metabolism, DNA (genetic material) manufacture and cell growth (especially red blood cells). It plays a large role in controlling homocysteine levels. It is associated with a reduced risk of birth defects and cardiac events. Folate food sources include legumes, egg yolk and fresh dark-green leafy vegetables. We can often find added folate in breakfast cereals and breads.

Vitamin C Vitamin C is water-soluble and must be eaten daily. Initial recommended levels of vitamin C intake were aimed at preventing diseases like scurvy (which cause skin and mucus membrane breakdown). Vitamin C plays a large antioxidant role in the human body. It is also involved in regenerating vitamin E. Food sources of vitamin C include fruits and vegetables. However, fruits and vegetables that naturally contain lots of vitamin C are often greatly affected by artificial ripening and storage before they get to the supermarket shelf. By the time you eat them, there is often little vitamin C left. Strawberries usually contain lots of vitamin C. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

Antioxidants Substances responsible for fighting tissuedamaging free radicals in the body

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Vitamin D Vitamin D is manufactured in the body when the skin is exposed to sunlight. It is required for calcium and phosphorus metabolism. This makes vitamin D essential for bone strength, muscle contractions, energy production and immunity. Vitamin D can be found in fish liver oil. Some dairy foods have also been fortified with vitamin D.

Vitamin E Vitamin E is an antioxidant that protects bodily membranes. Deficiencies in vitamin E can lead to neurological damage, muscle-function losses, DNA damage and heart problems. Vitamin E can be found in soybean oil, nuts, seeds and whole grains.

Water and hydration Water makes up about 60 per cent of human body weight. It is essential to human life. Water has many different functions. Water: • provides a transport medium for many substances, such as water-soluble vitamins • helps to cool the body down • is used in chemical reactions in the body. Fluid intake should be of primary importance in a healthy diet. Even small levels of dehydration are associated with a decrement in metabolic, circulatory and thermoregulatory function, especially in hot conditions. Dehydration can lead to a decrease in exercise performance, including impairment of skill and concentration. You should drink water regularly, and drink more if you are exercising, if the weather is warm or humid or if you are showing signs of dehydration, such as dizziness, thirst or fatigue. Thirst is not the best indicator of dehydration because you already require water before you feel thirsty. Recent studies have shown that carbohydrate electrolyte fluid intake may benefit activities lasting longer than 60–90 minutes and during intermittent high-intensity exercise. Athletes undertaking prolonged sessions of training or competition less than 12–24 hours apart may need special refuelling and rehydration strategies. Refer all athletes to an accredited dietitian for nutritional and fluid intake advice. Suitable fluids should be consumed in the hours before exercise to produce lightly coloured urine of normal or above normal volume. Some may benefit from drinking as much water as they can tolerate (e.g. 300–500 mL) just prior to exercise (e.g. 15 minutes before starting) if the exercise will not allow for as much fluid intake as required for that person. This may be particularly relevant for sports that do not have frequent drink breaks, such as soccer. Drinking before exercise helps prime the stomach to stimulate a more rapid gastric emptying of subsequent fluid intake during activity. This may help an athlete maximise fluid replacement during exercise in which sweat losses are extremely high. Athletes should experiment during training, rather than during competition, to ensure that they can tolerate such fluid levels without discomfort. Fluids should be palatable to encourage intake. For some athletes, carbohydrate electrolyte drinks (i.e. sports drinks) may be consumed in greater quantities than flavoured or plain water. This alone can enhance rehydration strategies. Cool drinks (15–20°C) are refreshing and can be consumed quickly in large volumes. Caffeine intake is always subject to debate. Dietary levels of caffeine have been shown to have measurable effects even at very low levels. Caffeine intake is associated with increased energy, alertness, motivation and concentration. For some people, caffeine intake may lead to excitability, anxiety and difficulty sleeping. There may be some physical dependency and withdrawal effects with excessive consumption.

Plant sterols and stanols Studies indicate that incorporating plant sterols and stanols into the diet may be effective in reducing total and LDL cholesterol  because they compete with cholesterol for absorption in the digestive system and humans do not produce them. They are natural substances found in nuts, legumes and Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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CHAPTER 2 Nutrition some breads and cereals. Some foods, such as margarines, yoghurts and milk, are fortified with plant sterols to help reduce cholesterol levels.

2.6  SUPPORTING POSITIVE ATTITUDES TOWARDS HEALTHY EATING AND BODY COMPOSITION A positive attitude towards eating involves a consistent approach that demonstrates awareness of the Australian Dietary Guidelines, used in combination with a physically active lifestyle. Nutrient intake that results in the best long-term outcome for athletes tends to relate little to the daily dietary requirements of sedentary people. It is also worth noting that in some places, even what would normally be considered a healthy diet may be lacking in vital nutrients due to damage to soil and food in the production process. As noted in the breakfast study described earlier in the chapter, people who eat breakfast also tend to lead healthier lifestyles than people who don’t eat breakfast. Generally, there tends to be a positive relationship in the attitudes of those with healthy eating patterns and their physical and mental health. Starvation or long periods without food will reduce kilojoule intake for that period, but the body is then starved of the nutrients that it needs to perform the daily functions of life. The body will look elsewhere to get the nutrients it needs, and this can lead to muscle breakdown. The weight shed by not eating is often lost as water and lean muscle mass (as well as some fat), which is not a healthy or sustainable combination. The eating patterns of clients vary according to their physical and mental state at the time. For example, clients may change their eating habits under stressful situations where a loss of appetite occurs. This may have an adverse effect on dealing with the stress, because energy levels may be lowered and the client may not be physically equipped to manage the stress as effectively. The opposite may occur as well, where the client may turn to food for comfort under stressful situations. Recognising these triggers will assist clients to deal with these issues. If there is a significant problem, referral to an appropriate healthcare professional may be required. Clients must learn to understand that what they eat will also affect their body composition, not just their weight. Eating patterns will affect their ability to exercise, sleep and concentrate. Diet can also affect self-esteem, mood and overall health. In some cases, it may be necessary for exercising clients to consult a dietitian about their eating habits. Clients who have difficulty achieving their nutritional goals should be referred to an accredited practising dietitian.

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1 a List all the foods you have eaten in the past 24 hours and analyse the nutrients you have consumed. b Describe the factors that may have affected the quality of the food you ate – for example, if the beans you ate had been stored in your fridge for 10 days. 2 Summarise the main functions of the vitamins and minerals discussed in this chapter, and research the name and function of one vitamin or mineral not mentioned in this chapter. Use the table provided below to record your research. An example has been provided to help you get started.

WORKOUT 2.2

Nutrient

Mineral or vitamin

Function/s

Calcium

Mineral

Increases bone strength



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3 What are the functions of the following substances? a Protein b Fat c Carbohydrate d Water: i List four water-soluble vitamins and research five food sources for each vitamin. ii Why do we need to consume foods high in water-soluble vitamins every day? iii List four fat-soluble vitamins and research five food sources for each vitamin. iv What is the major difference between water-soluble vitamins and fat-soluble vitamins? 4 Research the effects that different methods of cooking (e.g. steaming, boiling, grilling, baking and barbecuing) can have on three different foods – for example, beef, broccoli and chicken. Consider the effects on nutrient value and issues of food safety (e.g. for some foods it is imperative for safety that the food is completely cooked through and served hot). 5 Find recipes that you could use to modify the cooking method of traditionally ‘unhealthy’ food options – for example, hot chips, fried schnitzel, chicken nuggets and greasy take-away hamburgers. 6 Summarise your requirements as a fitness instructor in regard to referral of a client to an accredited practising dietitian. 7 List some dietary suggestions (e.g. replace some sugary drinks with water) to help clients make positive changes to their lives to maintain a healthy diet.

Management of body composition Body composition management is largely based on your metabolism, which is a set of chemical processes in the body that allow for life and normal functioning. These chemical processes require energy from food. Metabolism will determine how much energy your body will burn at any one time. Metabolism is ultimately controlled by hormones and the nervous system. Body composition management should involve healthy eating and a physically active lifestyle. Frequent small meals will help to increase resting metabolic rates. In general, for weight loss to occur, energy consumption must be less than energy expenditure; for weight gain to occur, energy consumption must generally be greater than energy expenditure. However, body composition management is really much more complex than this. Restricting energy consumption too much can lead to the breakdown of muscle tissue, rather than fat loss, as the body tries to compensate for the low energy provided to it by the diet. This may reduce the client’s weight but not achieve the fat loss so many people strive for. Energy imbalances are caused by many factors, mostly leading to weight gain rather than weight loss. Possible reasons for weight gain, especially fat gain, include: • family, work and social environments leading to poor eating and lack of exercise • stress affecting food choices and opportunities, as well as fat storage • yo-yo dieting affecting metabolism and the body’s ability to burn fat • medical conditions predisposing one to fat gain • medical treatments that exacerbate weight gain, such as corticosteroids • certain life events that create changes, such as cessation of smoking and marriage • life stages predisposing one to weight gain, such as pregnancy and menopause. A person with a higher resting metabolic rate will burn more energy at rest compared to someone with a lower resting metabolic rate. A combination of the food groups in appropriate proportions is recommended. Athletes or people with special dietary requirements may need to alter their food intake in conjunction with advice from an accredited sports dietitian.

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Portion control is a very important part of body composition management. The quality of food intake is also important; a highly processed low-fat snack may provide little health benefit. Appropriate snacks include fruit, high-quality yoghurt or a small handful of nuts. Fat gain in humans is thought to occur during certain life phases through either an increase in fat cell number (hyperplasia) or an increase in fat cell size (hypertrophy). However, this concept is still in

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CHAPTER 2 Nutrition need of further investigation (see Chapter 1 for more detailed information on fat cells). An increase in fat-cell numbers occurs in childhood, and therefore, to date, children are considered to be at risk of hyperplasic obesity if they gain excess weight. In adulthood, it is more likely that the number of fat cells will remain constant, but that they will increase or decrease in size with weight gain or loss, respectively. Although further research is needed, at this time an increase in fat cell numbers is thought to occur during: • childhood and early puberty • pregnancy in the foetus • adulthood, if extreme weight gain occurs. Current opinion is that if fat cells are filled to capacity in adults, more weight gain will result in more fat cells being made. The amount of fat cells a person has is part of the suggested reasoning behind why some people lose weight more easily than others. In other words, an adult who was lean as a child but then puts on a little extra weight as an adult will generally have less trouble losing weight than someone who was overweight as a child. However, current research is beginning to focus on the notion that fat cells might actually continually die and be replaced. This may explain, in part, why clients who undergo liposuction are not guaranteed a life without weight gain post-surgery. The location of fat storage on the body will vary among people and sexes. In general, women have a tendency to store fat on their buttocks and thighs, while men have more of a tendency to store fat around the tummy region. While fat around the tummy is more closely linked to diseases such as cardiovascular disease, with some effort it is usually easier to lose than fat around the thighs and buttocks. It does not take long to gain fat stores relative to gaining muscle, which can take months or years! There is also some evidence to support the notion that some fat on the buttocks and thighs may be protective against some chronic diseases. Is it possible that the extra fat may be there for a reason? This may explain why we (especially women) tend to put on fat as we age; however, further research is needed to clarify our understanding in this area of science. An exercise program that includes resistance training will help to improve lean body mass. Resistance training promotes muscle growth during recovery periods; therefore, it is important to allow rest time between sessions. Muscle growth requires an adequate dietary protein and kilojoule consumption. People with more muscle have a higher metabolic rate, which means that they burn more energy during the day. This is why fat-loss approaches that focus on excessive restriction of kilojoule intake are not effective in losing and maintaining fat loss in the long term. However, any increases in lean body mass will increase metabolism, which will help with energy expenditure, including fat loss, even when the person is not exercising. Clients’ programs can focus on increasing muscle strength and endurance while losing body fat. Some people are naturally thinner than others, and some of the possible reasons for this are that these people are: • genetically favoured towards fat-burning • leading physically active lifestyles • overexercising • disciplined regarding food intake • made up of a ‘lean’ body composition with healthy levels of muscle, fat, bone and fluid composition. In some cases, it is important that clients put on weight. To do this safely, it is best that they: • seek nutritional advice from a suitably qualified health professional, such as an accredited practising dietitian, where appropriate • check that their kilojoule intake is appropriate for the level of physical activity • avoid junk food • eat healthy meals and snacks. The Australian Government has published the Physical Activity and Sedentary Behaviour Guidelines for all age groups (Department of Health, 2014). This document provides recommendations on activity levels, sedentary levels and amounts of sleep for specific age groups.

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Current trends and fads

Low-carbohydrate diets Diets that focus on restricting carbohydrate intake, usually resulting in overconsumption of other nutrients

Many different diets and claims to a ‘quick fix’ for excess weight are just that – a quick fix. They are often low in kilojoules and vital nutrients and inadequate for optimum health. While weight loss may occur rapidly with some of these approaches, the weight lost is often a combination of water and muscle bulk, leaving much more fatty mass than before the weight loss began. The muscle can be hard, if not impossible, to regain once it is lost. Many weight-loss fads have little or no exercise involved in their recommendations, yet exercise is necessary to improve long-term health and to decrease the risk of diseases such as heart disease. Exercise uses energy, and so it is a great way to burn the kilojoules that you consume in your food. In addition to this, resistance exercise increases lean body mass, which has a higher metabolic rate than fat. Low-carbohydrate diets are very popular in today’s society. Currently, there is no evidence to support the achievement of long-term weight loss on these diets. Many of the diets involve severe restriction of important nutrients such as calcium, fibre and folate. The kilojoules lost from not eating carbohydrates are often compensated for by a diet high in saturated fat. The average person does not need to analyse and count every kilojoule. Choosing quality food with a metabolic-enhancing effect is what matters. Low kilojoule consumption reduces metabolic rate as the body goes into ‘starvation mode’ to survive. Most ‘diets’ fail because they are not specific to the individual and their metabolism in regard to food choices and portions, and the calculations required are too complicated and/or irrelevant.

2.7  REFERRAL REQUIREMENTS Your requirements in relation to referral have been mentioned from time to time throughout this chapter. It is imperative that you understand that your role as a fitness instructor is to provide healthy eating information according to the Australian Dietary Guidelines. You must refer clients to an accredited practising dietitian, accredited sports dietitian or a general practitioner when a client has specific concerns or questions about: • dietary trends • fad or popular diets • nutritional supplementation • sports foods • ergogenic aids (i.e. anything that provides a physical or psychological benefit when exercising).

WORKOUT 2.3

1 What nutritional information could you, as a fitness instructor, give to a client (without trying to play the role of an accredited practising dietitian) who wants to do the following? a Reduce body fat levels. b Increase lean body mass. 2 What are the recommendations for a healthy level of daily fluid intake? (Be sure to consider alcohol consumption.) 3 What factors may affect the hydration status of a client? 4 Research the names of five antioxidants. Provide examples of foods that contain these antioxidants. 5 Research the function of: a selenium b calcium. 6 Research the recommendations for nutrient intake for a competitive athlete. 7 Analyse the current eating habits and attitude towards nutrition of a friend or family member. What are the positive and negative aspects of this eating pattern and attitude for that particular person?

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CHAPTER 2 Nutrition

Chapter summary The Australian Dietary Guidelines have been published and updated by the National Health and Medical Research Council several times. The most recent version was published in 2013. These guidelines provide fundamental information to help a fitness instructor work within their scope of practice in regard to nutrition. The Guidelines provide a useful tool to fitness instructors to help guide clients to a healthy weight through the consumption of a variety of healthy food. They advocate for the maintenance of healthy weight, food variety, limiting salt and sugar intake, encouraging breastfeeding and maximising food safety. As a fitness instructor, you are well placed to promote a balanced diet to clients. We have discussed Fitness Australia’s guidelines, which outline what is within your scope of practice and when to refer a client to an accredited practising dietitian. Remember to lead by example and model for your clients a healthy weight and a positive weight-loss attitude. Nutrition is a complex area of science. You must be willing and ready to continue to learn and keep up-to-date with guidelines in this area. Many clients will have specific macro- and micronutrient needs, and these can vary at different times in their life. You can use Australian guidelines to assist clients, but be ready to refer clients to an accredited practising dietitian when their requirements are beyond the scope of practice of a fitness instructor. Managing the body composition of clients is complex. There are so many factors that influence body composition, and food intake is just one of these. Body composition can also be affected by exercise, incidental activity, sleep and stress patterns. A client’s metabolism is also vital to the achievement of body composition goals. Remember that metabolism is affected by many factors, not just eating patterns, and you can help clients to achieve body-composition goals by writing an appropriate fitness program. Clients who have questions about dietary trends, fads or popular diets, supplements, medical conditions or ergogenic aids must be referred to an accredited practising dietitian, accredited sports dietitian or a general practitioner/allied health professional, as required.

Review questions 1 List and summarise the five recommendations from the Australian Dietary Guidelines. 2 Explain the difference between weight and body composition. 3 List five realistic strategies that you could use to help clients to adapt their current food choices to healthier options. 4 What is metabolism? 5 What type of exercise can help in increasing a client’s metabolism in order to lose weight? 6 Provide three examples of situations in which you should refer a client to an accredited practising dietitian. 7 Describe some behaviours that may indicate a client possibly has an eating disorder. 8 What is the potential relationship between body composition and mental health? 9 Explain how following the Australian Dietary Guidelines can help with weight loss. a List three situations in which a client may need a large variation to the Australian Dietary Guidelines. b For each situation you listed in question 9a, state the appropriate medical or allied health professional to refer the client to. 10 Choose a packaged item and analyse its nutrition panel. a Are there any positive aspects to this food as a healthy food choice? For example, is it low in sugar? Does it contain lots of real fruit? b Can you find a healthier food choice? What would you look for in a replacement product? c Does the item contain any food additives? If so, what are they? Research and list any known side effects of these additives.

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11 Find three packaged food products in the supermarket that are often marketed as ‘healthy’, such as muesli bars. a Do the products contain hidden fats? b Do they contain high levels of sugar or sugar alternatives? c Do they contain additives? d Are there misleading claims on the packaging? For example, if the food is claimed to contain fruit, is the fruit real or is the food simply flavoured? e Are there healthier alternatives to these products? 12 What recent diet fads or myths have you heard about? List at least five and explain your understanding of them. (Discuss with your colleagues or do some further research to clarify the truth.) For example, it is a myth that the word ‘lite’ on a package means ‘low-fat’ and that it will help you lose weight.

CASE STUDY 2.1 Anne Marie Capati (37 years) was a member at Crunch Fitness who, during a session with her personal trainer, suffered a stroke and died. Her death was caused by supplements that her personal trainer had instructed her to take, which included four over-the-counter supplements, one of which contained ephedra. Ephedra is a stimulant containing ephedrine that is used to facilitate weight loss, but that has been linked to dozens of deaths. Capati had disclosed to her personal trainer that she was taking prescribed medications for her hypertension (high blood pressure). The personal trainer also provided a detailed list of how much and when to take the supplements that caused her death (Pristin, 1999). 1 Was the trainer working within his scope of practice? Explain why or why not.

CASE STUDY 2.2 Stuart is a 54-year-old old business executive who has put on 8 kg of weight due to increasing work commitments, consuming lots of fast food and skipping meals. His work also requires him to travel and have business meals with clients involving restaurants and drinking alcohol. 1 What dietary advice can you provide for Stuart, remembering to work within your scope of practice?

Weblinks Australian Guide to Healthy Eating https://www.eatforhealth.gov.au/guidelines/australian-guide-healthy-eating Fitness Australia: Nutrition Advice within Scope of Practice for AusREPS (PDF) https://fitnessaustralia-production.s3.amazonaws.com/uploads/uploaded_file/file/242841/ Nutrition_Advice_within_SoP_for_AusREPs_F.pdf Fitness Australia: Nutrition infographic https://fitnessaustralia-production.s3.amazonaws.com/uploads/uploaded_file/file/242786/ Nutrition-Infographic-Tips.png Fitness Australia: Referral to nutritionist infographic https://fitnessaustralia-production.s3.amazonaws.com/uploads/uploaded_file/file/242787/ Nutrition-Infographic-Refer.png

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PART 2 Fitness orientation and health screening

CHAPTER 3 Fitness orientation and health screening

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CHAPTER

3

Fitness orientation and health screening

OBJECTIVES This chapter involves application of the following topics: 3.1 Client orientation and induction 3.2 Identification of client fitness requirements 3.3 Administering pre-exercise health screening questionnaires 3.4 The Adult Pre-exercise Screening System (APSS) 3.5 Administering pre-participation health screenings 3.6 Referrals to medical practitioners 3.7 Making appointments for fitness appraisals and advising clients on the benefits of exercise prescription 3.8 Confidential client records.

LO

INTRODUCTION The benefits of exercise to the general population are clear, but for the exercise professional it can be difficult to determine if a client can exercise safely and what their needs and expectations are. The fitness instructor must identify those needs and expectations to ensure the client’s goals are achieved. Clients vary in their motivation levels, exercise experience, activities and age. They may have a range of social, cultural or ethnic backgrounds, along with varying physical and mental abilities, and they may or may not have been previously screened for exercise. The discussion and recording of these details is often referred to as the orientation of the client to exercise. The Adult Pre-exercise Screening System (APSS) has been developed through collaboration by Fitness Australia, Exercise and Sport Science Australia and Sports Medicine Australia. In the screening stage, the APSS can be used to determine if a client needs to be referred to a medical practitioner, such as a general practitioner (GP) or allied health professional, for a medical opinion before starting an exercise program. The implementation of the APSS can help minimise liability risks relating to lifethreatening complications or injuries that occur during exercise. Also remember that appearances can be misleading; implementing the APSS can avoid stereotypes about clients, such as the assumption that an older client is inactive and unfit.

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CHAPTER 3 Fitness orientation and health screening To establish maximum rapport with a client, be prepared and do the following: • Greet the client in a friendly and courteous way. • Introduce yourself and your position to your client. • Place the client in a comfortable position. • Use eye contact. • Place yourself in a position with clear access to the client and required materials. • Provide written information on the organisation’s facilities, products and services. • Speak at an appropriate pace. • Listen to the client and work with them to achieve goals.

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The steps involved in starting an exercise program with a client include the following: 1 Client orientation. Collect and assess information, including about the client’s current physicalactivity patterns, and identify and clarify the client’s needs and expectations. 2 Pre-exercise screening procedures. Use a questionnaire to identify whether a medical appointment or referral is required, and to determine the level of risk in the client’s participation in exercise and physical activity. 3 Fitness appraisal. This involves fitness assessments of clients, where necessary. 4 Prescription of an exercise program. 5 Exercise training sessions. 6 Regular review of the exercise program and reassessment of fitness appraisals – for example, reassessment of muscle strength after six weeks of training. This chapter will focus on the first two parts of this process – client orientation and health screening.

3.1  CLIENT ORIENTATION AND INDUCTION Client orientation and induction is the first step in introducing a client to a physical-activity program. It is common for prospective clients to be anxious and possibly intimidated about beginning an exercise program, so you should attempt to make any new client comfortable in their new surroundings. Remind the client that the information you gather will be treated in a confidential manner. You must gain informed consent to share the information with other parties. Once the information has been gathered, it forms the beginning of your client’s file and should be stored appropriately for future reference and comparison. It is becoming popular for fitness instructors to complete electronic copies of these forms. This reduces the use of paper and maintains client privacy. When gathering and recording information from a client regarding health or lifestyle, you can use an interview process whereby you ask the client a question and then record the answer on the appropriate form. See Table 3.1 for the content that is to be included in these forms. Speak clearly and confidently, and stop to confirm understanding or to answer questions from the client. Avoid making assumptions or finishing the client’s sentences; instead, try to adopt a relaxed interviewing technique. This process has a number of advantages, since it: • formalises the process and follows a screening tool endorsed by Fitness Australia • allows you to elaborate on or clarify any questions your client does not completely understand • prevents your client from simply indicating ‘Yes’ or ‘No’ without actually reading the question • allows your client to completely formulate their views • allows you to record additional information that your client considers to be important • affords you time to think about the client’s responses.

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Table 3.1 Information collection forms Form

Purpose

Pre-exercise screening

• Gathers medical information • Used to assess health and readiness to participate in testing and programming • Determines level of risk for starting an exercise program

Release or waiver

• Used to assist in the prevention of legal action initiated by the client in the event of negligence

Informed consent

• Used to inform the client of their rights and responsibilities in being involved in exercise testing and programming

Fitness facility tour After appropriate paperwork has been completed, it may be appropriate to take the client on a more detailed guided tour of the fitness facility. This will expose the client to the environment they will be using with the aim of making them feel more comfortable in the new environment. This will further assist in building rapport with the client and allow you to provide safety information. At the end of the client interview and facility tour, you should ensure the client understands whether they are cleared to exercise and undergo a fitness appraisal or need to be provided with a referral letter to a medical practitioner (such as a GP) to be cleared for exercise. In any case, the details of the client’s next appointment for fitness testing should be confirmed.

WORKOUT 3.1

1 Collect three pre-exercise screening forms and lifestyle screening forms (each fitness facility will have slightly different forms, depending on their organisational policies and procedures). a Describe the advantages and disadvantages of each form. b Is the fitness facility using industry-recognised forms? Why or why not?

3.2  IDENTIFYING GENERAL CLIENT FITNESS REQUIREMENTS Identifying clients’ requirements can be a complex process in which previous exercise experience may greatly influence clients’ expectations. Clients’ needs may also change over time. For example, a client who has lost 10 kg to achieve their first weight-loss goal may now wish to increase their muscle bulk. This will involve modification to the current program, such as increasing the weight being lifted or changing the type of exercise. Making changes to a program can be tricky. Potential problems with program changes include deciphering how much should be changed at any one time. Too many changes in one session or in a small timeframe can cause excessive overload and risk of injury and can compromise performance. Helping clients to reach their goals requires progressive overload, but within reason. For example, an increase in weight of about 5–10 per cent in one week is enough to overload most clients. Remember that everyone responds differently to stress and exercise. Too many very hard sessions per week in which the client is working at near maximal effort for extended time periods can increase the risk of injury, and other overtraining signs and symptoms (e.g. excessive muscle soreness and prolonged recovery from exercise sessions) may start to appear. Fitness programs are covered in detail in Chapter 5.

Requirements and expectations of the client Client fitness requirements may not match client expectations. For example, a client who wants to lose ‘belly fat’ may not understand the benefit of resistance training but instead be more focused on strict dieting and lots of cardio training because that’s ‘what the neighbour said they should do’. Educating clients is the most effective way to help them achieve their goals. This will encourage clients to take more responsibility and ownership of their progress. This may include examining and Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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reporting on parts of the program that are fun or not so fun, effective or not so effective. The client and the fitness instructor may then liaise regarding: • modification of the current exercise program • additions to the exercise program • potential problems and solutions • monitoring of the program and progress. Questions that may be used by a fitness instructor to help identify client requirements and expectations include the following: • What fitness services are you interested in, and are there any particular reasons for these preferences? • What are your fitness goals? For example, do you expect to lose body fat? Run a marathon? Improve a medical condition? How do you think you will achieve these goals? • Do you have any specific exercise preferences – for example, cycling over running? Why? • What outcomes do you expect to achieve? What timeframes do you have to achieve these goals? • Are there any additional benefits that you think this program will provide – for example, improved stress management or increased self-esteem? • Do you have a budget allocated for your participation in this exercise program? • How much time are you willing to make available for exercise? Do you envisage that time availability will be an obstacle for you? (You can then discuss whether the available time is sufficient for achieving their goals.) How do you perceive this program fitting in to your current lifestyle?

Budgetary constraints A client may baulk at the cost of their exercise program. As an instructor, you can discuss the potential long-term financial benefits of being fit and healthy – for example, decreasing the risk of heart disease and other chronic illnesses. If the short-term cost is still a factor for the client, you can attempt to liaise with them to establish the most appropriate and cost-effective way to achieve their goals within their budget. For example, you may investigate cheaper fitness-facility membership plans, establish a home exercise program with lots of incidental exercise, or use outdoor training for part of or the entire program. Working with a client to factor exercise into their lifestyle may reduce the number of structured sessions and enable the client to work within their budget. 1 What are your current personal fitness goals? 2 Consider your current level of physical activity, then answer the following questions: a Does your level of physical activity satisfy your personal fitness goals? b How can you improve your current fitness regimen to satisfy your personal fitness goals? Make a list of obstacles that limit you in reaching your fitness goals and offer some solutions. For example: you have no time to exercise before work. Leave for work a few minutes earlier and park your car a 15-minute walk away so you will add 30 minutes of walking to your daily activity. 3 Interview a colleague who can play the role of a new client. Using the questions suggested earlier (and any additional questions you deem appropriate), identify your client’s requirements and expectations.

3.3  ADMINISTERING AND PROCESSING PRE-EXERCISE HEALTH SCREENING QUESTIONNAIRES Pre-exercise screening questionnaires, or health screening questionnaires, have existed in the fitness industry for many years. In Australia, however, there has at times been confusion about which questionnaire is appropriate to use in a given situation. There is currently no law that governs which pre-exercise screening questionnaire you use. It is always wise, though, to use industry-endorsed or recognised procedures or systems – and the pre-exercise screening procedure is no exception. In this chapter, we will cover the pre-exercise screening procedures currently recognised in Australia, along with the one developed and recognised by the American College of Sports Medicine (ACSM) (see Figure 3.1). Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-202

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Figure 3.1 The American College of Sports Medicine health screening recommendations Reprinted with permission of the American College of Sports Medicine. Copyright © 2018 American College of Sports Medicine.

Risk stratification The process of determining the level of risk associated with the client participating in exercise

No matter which pre-exercise screening procedure you decide to use, there are a few steps that you should always follow in order to protect your client and maintain their safety. Administering a preexercise health-screening questionnaire should involve you: • explaining to the client the purpose of the pre-exercise screening questionnaire and risk stratification. Risk stratification processes involve collecting all the information that you have gathered and using that information to determine the level of risk, or risk classification (usually low-, moderate- or high-/higher-risk), associated with exercise for the client • providing and administering to the client an industry-standard pre-exercise health screening questionnaire according to the policies and procedures of your organisation • using the information gathered to form the basis of a discussion with the client. This is a great time to discuss the client’s preferences and the outcomes of the pre-exercise screening procedure

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CHAPTER 3 Fitness orientation and health screening • referring the client for any situations that require a medical opinion before commencing a fitness program or increasing the intensity of a fitness program. You or the client may require some additional guidance from a medical practitioner, such as a GP, before prescribing a fitness program. Sometimes the client’s preferences or requirements will lead you to refer the client to a fitness professional who is highly qualified, such as a personal trainer or an advanced personal trainer. It is important to always work within your scope of practice as a fitness instructor. Refer your client to a GP or allied health professional for a medical opinion if necessary. You will need to acquire informed consent to be able to share the client’s information with the medical practitioner before referring the client. An email to the client’s doctor can reduce the need for a hard-copy letter and provide confidentiality for the storing of client records.

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Why screen clients before they start exercise?

Informed consent Refers to the exercise professional asking the client’s permission before passing on personal details to their GP in a referral letter

It is well known that, for most people, the benefits of physical activity outweigh the risks. However, it is also recognised that for some people there may be unacceptably high risks associated with participating in exercise or substantially increasing their level of physical activity. The overall risk of a cardiovascular or cerebrovascular event, such as a heart attack, stroke or sudden death, increases during physical activity. It should always be your intention to minimise or remove risks where possible, but an adverse event may still occur although precautions are taken.

Heart attack Occurs when the heart stops receiving enough blood to function properly, typically resulting in the death of part or all of the heart

Physical-activity recommendations People who are free of cardiovascular, metabolic or significant respiratory disease, and those without any signs and/or symptoms of a disease or injury, can begin light- to moderate-level physicalactivity programs without the need for medical referral. The National Heart Foundation of Australia and the Australian Government also support regular participation in physical activity. They currently recommend the following: • Doing any physical activity is better than doing none. If you currently do no physical activity, start by doing some, and gradually build up to the recommended amount. • Be active on most, and preferably all, days every week. • Accumulate 150–300 minutes (2.5 to five hours) of moderate intensity physical activity or 75 to 150 minutes (1¼ to 2½ hours) of vigorous intensity physical activity, or an equivalent combination of both moderate and vigorous activities, each week. • Do muscle strengthening activities on at least two days each week. 2014 Commonwealth of Australia as represented by the Department of Health.

Negligence and duty of care It is good practice to follow an industry-recognised pre-exercise screening system in order to, at least partly, demonstrate that you have upheld your duty of care to your client if something goes wrong. Legally, a claim of negligence requires three elements to be satisfied: 1 A duty of care must be established between the plaintiff (the person making the claim) and the defendant (the person defending the claim). 2 There must have been a breach in that duty of care. 3 The damage (injury) must have been caused as the result of that breach of duty of care. While it is not mandatory, or required by law, to do so, following industry-recognised procedures may form part of your supporting argument that you upheld your duty of care to your client if an injury or other damages occurred.

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Stroke The sudden death of brain cells due to an inadequate supply of blood flow to the brain

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3.4  THE ADULT PRE-EXERCISE SCREENING SYSTEM (APSS) As introduced earlier, the Adult Pre-exercise Screening System (APSS) was developed in Australia by three fitness and sport-registration organisations in Australia: Fitness Australia, Exercise and Sports Science Australia and Sports Medicine Australia. The APSS consists of: • a pre-exercise screening tool • a pre-exercise screening textbook. The APSS is not intended to be a substitute for advice from a medical professional. However, it is useful to be aware of how this system works if the fitness organisation in which you work decides that this will be the pre-exercise screening tool that is implemented for clients. The information that follows is in no way intended to replace the information that is in the APSS textbook (Norton & Norton, 2011), and it is highly recommended that you refer to that textbook for further information on how to use the APSS. This chapter will provide an overview of the Adult Pre-exercise Screening Tool only. The APSS consists of three stages, with Stage 1 being compulsory and Stages 2 and 3 considered optional. Stage 1, the compulsory part of the pre-exercise screening, consists of seven questions which have been designed to help determine if a person has any major uncontrolled cardiovascular, metabolic or respiratory diseases, any signs or symptoms of a disease, or any other medical issues that may contribute to their being at increased risk should they decide to start an exercise program or upgrade their physical-activity intensity or patterns. Stages 2 and 3 provide an opportunity for further questioning about specific risk factors and other lifestyle behaviours, which will provide further detail to assist with determining the best course of action for the client.

Stage 1 of the APSS (compulsory) Stage 1 of the APSS has been designed to be self-administered and self-evaluated by the user. This means that there is an option for the client to complete this questionnaire online or in a hard-copy format without necessarily having a fitness or health professional ask them questions or assist them in any other way. However, the client should be given the opportunity to seek assistance or ask questions before commencing the exercise. Stage 1 was designed to identify clients who may be at higher risk of an adverse event occurring during physical activity. There are seven questions for the client to answer which are used to identify any known disease or signs or symptoms of disease. If they answer ‘Yes’ to any of these questions, they are advised to seek guidance from their general practitioner (GP) or an appropriate allied health professional prior to starting a physical-activity program. The exercise professional can provide a referral letter to explain to the medical practitioner why the client is being referred. If the client answers ‘No’ to all seven of the questions and they have no other health concerns, they will be advised that they can commence a light- to moderate-intensity physical-activity or exercise program. According to the APSS, ‘moderate-intensity’ exercise is any aerobic activity that can be conducted by the client while maintaining a conversation uninterrupted. The APSS also states that the intensity should allow the person to continue exercising for 30–60 minutes.

The compulsory questions in Stage 1 As you can see in Figure 3.2, the seven compulsory questions seem straightforward. However, you are recommended to seek further advice from the textbook supporting this tool to help you make your decision as to whether or not medical referral is warranted. Let’s look more closely at why the questions in Stage 1 are so important.

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CHAPTER 3 Fitness orientation and health screening

Figure 3.2 Adult Pre-exercise Screening Tool for Stage 1 Note: See Chapter 5 for information about determining exercise intensity. Source: Exercise and Sports Science Australia, Fitness Australia and Sports Medicine Australia.

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Asthma A common chronic inflammatory disease of the airways. It is characterised by symptoms such as coughing, wheezing, chest tightness and shortness of breath

Insulin The hormone responsible for lowering blood glucose levels

Hyperglycaemia A medical condition caused by excessive blood glucose levels

Hypoglycaemia A medical condition caused by low blood glucose levels

PART 2: FITNESS ORIENTATION AND HEALTH SCREENING

If the client answers ‘Yes’ to any of these questions, this can help you to decide if it is safe for them to participate in exercise. You can make a decision based on further questioning to determine if they need a referral; however, if in doubt, recommend a referral. • Heart conditions. Consider a client who had a heart attack 10 years ago, but has had no signs or symptoms of heart conditions since and who may truly benefit from participating in light- to moderate-intensity exercise. Knowledge of the client’s current level of activity, the severity of the cardiovascular condition and any comorbidities (i.e. other concerns or conditions they have) helps you to determine the approach and rate of progress of the fitness program. The client may also have a clearance and management plan for their condition whereby medications and safe monitoring of the client will assist in providing an appropriate level of exercise. Flexibility in meeting exercise requirements is also an option, where the recommended 30 minutes of exercise may be completed all at once or accumulated throughout the day and still achieve health benefits – for example, performing three 10-minute bouts of exercise during each day. This can be particularly useful if there are time restrictions or the client’s fitness is particularly low, because it gives the client more time to recover. • Unexplained chest pain. Sometimes chest pains are described by clients as constricting, burning, knife-like or a dull ache. These symptoms can potentially be related to a lack of oxygen reaching the heart muscle. This can occur for many reasons, but often because there is some sort of blockage in the arteries. In these cases, the client must be referred to a GP for a medical opinion to ensure that it is safe for them to exercise and/or to see if the client requires medical treatment. Remember that exercise requires the heart to be able to pump more blood around the body. The blood carries the oxygen to the working muscles, but it is also required to supply the heart with oxygen. If there is already a partial blockage in the arteries and the person is then asked to exercise at an intensity at which their body cannot cope, the oxygen supply to the heart and brain may be compromised and a heart attack or a stroke can occur. • Faintness or dizziness. Dizziness and light-headedness can be related to low blood pressure. The client feeling light-headed or dizzy often occurs when quickly changing positions, such as from sitting to standing, where the body takes a short moment to adapt to the change in position and get the blood to where it needs to be. This transient light-headedness is usually ‘normal’. But, if the person regularly reports feeling dizzy or light-headed for no apparent reason, they should be referred to a GP. • Asthma is a cause for concern for many people. A lot of people live with asthma and manage it well with their prescribed medications. You should question your client regarding how well managed their asthma is and how effective their medications have been. Clients who regularly have asthma attacks or who have had an attack in the past 12 months must be referred to a GP. • Diabetes mellitus will also be covered in more detail in Chapter 12. Let’s look briefly at this disease here in order to help you to determine the need for referral and the level of risk of the client. Diabetes mellitus is an inability to properly control blood glucose levels (BGLs, also referred to as blood sugar levels) in the body. This occurs because the pancreas, which normally helps to control blood glucose levels through the release of a hormone (a chemical messenger) called insulin, is having trouble doing its job properly. Type 1 diabetes, which is typically a genetic condition, occurs when the pancreas does not produce enough insulin to control BGLs. People with type 1 diabetes usually require regular insulin injections to keep their BGLs stabilised. Type 2 diabetes occurs when lifestyle habits, such as lack of exercise and unhealthy eating, place so much stress on the pancreas over time that the pancreas starts to fail at doing its job properly. People with type 2 diabetes also have trouble controlling their BGLs. BGLs can be greatly affected by exercise participation. Many clients with type 1 or type 2 diabetes can exercise safely if their condition is managed well and they know how to recognise signs and symptoms of hypoglycaemia (low blood glucose levels) or hyperglycaemia (high blood glucose levels). See Chapter 12 for more details on the signs and symptoms to be aware of in diabetic clients.

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CHAPTER 3 Fitness orientation and health screening Symptoms of hyperglycaemia include: • convulsions • anxiety • cold sweats • sleepiness • weakness • dizziness/light-headedness • confusion • difficulty speaking • shaking or trembling • double or blurry vision • irritability • lack of concentration.

Symptoms of hypoglycaemia include: • hunger • sweating • shakiness • dizziness • nervousness/anxiety • confusion.

• Acute muscle aches and pains can happen in anyone. Not all aches and pains should cause you to refer your clients to a health professional. However, you should be able to determine what conditions require referral and also how to modify exercise to ensure that any exercise you prescribe is safe and effective. Chronic musculoskeletal conditions can cause daily aches and pains. Again, this does not mean that people with these conditions cannot exercise. See Table 3.2 for a list of chronic conditions you may encounter in clients that will require you to consider whether or not a GP referral is required.

Table 3.2 Conditions that can cause musculoskeletal aches and pains Condition

Description

Cerebral palsy

A range of disabilities associated with movement and posture; signs and symptoms vary

Chronic muscle fatigue

A condition in which the person experiences abnormally high levels of fatigue after exertion, such as physical activity

Muscular dystrophy

The name given to a group of inherited muscle diseases that cause progressive weakening and degeneration of muscles

Parkinson’s disease

A progressive, degenerative neurological condition that results in tremor and rigid, slowed movements

Osteoarthritis

A disease of the joints in which the normal protective cartilage is damaged and broken down, resulting in pain and stiffness at the affected joints Note: There are many different types of arthritis. Osteoarthritis is one type of arthritis

Scoliosis

A sideways S- or C-shaped curvature of the spine

Spondylolisthesis

A forward displacement of one vertebra over the vertebra beneath it

Bone fracture

A break in a bone

Osteoporosis

When the density of bone is reduced, causing the bones to become brittle and fragile

Serious sprains and strains

A sprain is a partial or full tear in a ligament (the connective tissue connecting bone to bone) and a strain is a partial or full tear in a tendon (the connective tissue connecting muscle to bone) or a muscle

Joint replacement

When part or all of the bones at a joint are replaced

At the end of Stage 1 of the APSS, there is the opportunity (in question 7) for the client to indicate if they have any other concerns or medical problems that have not already been covered.

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LANGUAGE AND LITERACY SKILLS

Making a decision after Stage 1 If the client answers ‘Yes’ to any of the seven questions, they should be advised to seek guidance from their GP or appropriately qualified allied health professional. If you are at all unsure, refer the client to their health practitioner. If they answer ‘No’ to all seven questions, they may proceed to participate in appropriate light- or moderate-intensity exercise. See Figure 3.3 to determine what is an appropriate exercise intensity.

Stage 2 of the APSS (optional) The aim of Stage 2 of the APSS is to identify those clients with risk factors or other conditions so as to assist appropriate exercise prescription (see Figure 3.4). This stage is designed to be administered by a qualified exercise professional with a minimum qualification of a Certificate III in Fitness and completion of relevant training and assessment in this area (refer to the APSS for further information). In Stages 2 and 3, a risk stratification process can be implemented and the level of risk assigned. If a client has fewer than two risk factors, they are considered ‘low’-risk; if they have two or more risk factors, they are ‘moderate’-risk. After determining the level of risk, the exercise professional can now make a clear decision about the need for referral and the level of exercise intensity for the client. However, you should use the APSS tools, in combination with your professional judgement, to determine the best course of action for a client. Physical activity must be encouraged, not discouraged, and sometimes screening tools exaggerate the risk allocated to a client. Risk factors that are examined in this stage of the screening tool are listed later in this section in Figure 3.4.

Completion of Stage 2 As a fitness instructor, you are well within your rights to stop the client’s APSS pre-exercise screening procedure at Stage 2. Remember that Stage 2 allows you to classify a client as having a ‘low’ or ‘moderate’ risk. As stated above, low-risk clients are those who have fewer than two risk factors, while moderate-risk clients have two or more risk factors. You will need to look specifically at each of the risk factors to determine if a medical referral is warranted and the risk of the client starting the exercise program. After examining all the risk factors, you will need to decide whether the client should be referred to a medical practitioner before starting exercise.

Stage 2: Risk stratification according to the APSS At the completion of Stage 2, total all the risk factors from questions 1–8 and determine if the client is low-risk or moderate-risk: • Low-risk: Clients may participate in aerobic physical activity and exercise up to a vigorous or high intensity level according to the exercise intensity guidelines shown in Figure 3.3. • Moderate-risk: Clients may participate in aerobic activity and exercise at a light or moderate intensity according to the intensity guidelines shown in Figure 3.3.

LANGUAGE LITERACY AND NUMERACY SKILLS

Stage 3 of the APSS (optional) The aim of Stage 3 of the APSS is to obtain pre-exercise baseline measurements of other recognised cardiovascular and metabolic risk factors (see Figure 3.5). Measures 1, 2 and 3 of this stage must be administered by a fitness professional with a minimum qualification of Certificate III in Fitness. However, Measures 4 and 5 must be administered by an appropriately qualified allied health professional, such as an exercise physiologist. This is because some higher-level measurements need to be taken.

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CHAPTER 3 Fitness orientation and health screening

EXERCISE INTENSITY GUIDELINES INTENSITY CATEGORY

SEDENTARY

LIGHT

HEART RATE MEASURES

< 40% HRmax

40 to < 55% HRmax

PERCEIVED EXERTION MEASURES

DESCRIPTIVE MEASURES

Very, very light RPE# < 1

• Activities that usually involve sitting or lying and that have little additional movement and a low energy requirement

Very light to light RPE# 1−2

• An aerobic activity that does not cause a noticeable change in breathing rate • An intensity that can be sustained for at least 60 minutes

MODERATE

55 to < 70% HRmax

Moderate to somewhat hard RPE# 3−4

• An aerobic activity that is able to be conducted whilst maintaining a conversation uninterrupted • An intensity that may last between 30 and 60 minutes

VIGOROUS

HIGH

70 to < 90% HRmax

≥ 90% HRmax

Hard RPE# 5−6

Very hard RPE# ≥ 7

• An aerobic activity in which a conversation generally cannot be maintained uninterrupted • An intensity that may last up to about 30 minutes

• An intensity that generally cannot be sustained for longer than about 10 minutes

# = Borg’s Rating of Perceived Exertion (RPE) scale, category scale 0−10

Figure 3.3  Exercise intensity guidelines Source: Exercise and Sports Science Australia, Fitness Australia and Sports Medicine Australia.

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CHAPTER 3 Fitness orientation and health screening →

Figure 3.4 Adult Pre-exercise Screening Tool for Stage 2 Source: Exercise and Sports Science Australia, Fitness Australia and Sports Medicine Australia.

Stage 3 requires measures of the following: • Anthropometry: — BMI, which needs to be calculated after weight and height are measured by the fitness instructor (see Chapter 4 for how to do this) — Waist girth (centimetres) (see Chapter 4 for how to do this). • Blood pressure: — Resting blood pressure (mmHg) (see Chapter 4). • Blood measures: — Blood fats: • Total cholesterol (mmol/L) • High-density lipoprotein (HDL) (mmol/L) • Triglycerides (mmol/L) • Low-density lipoprotein (LDL) (mmol/L). • Fasting blood glucose (mmol/L). In Stage 3, risk factors are assigned to each of the variables that are measured. The highest possible number of risk factors is nine. Let’s look more closely at some of these variables to see how they contribute to the client’s risk level. Weight and height do not individually carry a risk factor, but BMI does. HDL can be given a positive or a negative risk factor. As noted in Chapter 2, HDL is sometimes considered ‘good’ cholesterol. Therefore, if HDL is greater than 1.55 mmol/L it is considered to be ‘good’, but if it is less than 1.00 mmol/L it is considered ‘bad’. You will also need to carry forward any risk factors that the client accumulated in questions 1–4 of Stage 2. Stage 3 measurements of variables such as BMI and blood pressure supersede the Stage 2 responses, which were based on questions alone. In other words, if there are any differences between the client’s responses in Stage 2 and the measurements taken in Stage 3, use the Stage 3 answers rather than the Stage 2 responses to calculate the total risk-factor score. Refer to Chapter 4 for standard measuring techniques.

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Figure 3.5 Adult Pre-exercise Screening Tool for Stage 3 Source: Exercise and Sports Science Australia, Fitness Australia and Sports Medicine Australia.

LANGUAGE LITERACY AND NUMERACY SKILLS

Online pre-screening tool Fitness Australia has developed an online version of the APSS tool for use in fitness facilities. This will assist you to use an electronic version of the pre-screening form for the safe recording and storage of clients’ files, as well as reduce the impact of physical resources. This online version is not editable for branding but will meet the national standards that are supported by industry authorities. It is available at http://www.fitnessriskmanagement.com.au/screening-tool/.

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3.5  PRE-PARTICIPATION HEALTH SCREENING The American Heart Association (AHA)/ACSM Health/Fitness Facility Pre-participation Screening Questionnaire (see Figure 3.6) is a self-reported health-risk appraisal which is recommended for anyone who wants to begin a physical-activity program. This screening form can be used as an alternative to the APSS, and is implemented and reviewed by the exercise professional, with the information gathered being stored confidentially. Assess your health status by marking all true statements History. You have had: a heart attack heart surgery cardiac catheterisation coronary angioplasty (PTCA) pacemaker/implantable cardiac defibrillator/rhythm disturbance heart valve disease heart failure heart transplantation congenital heart disease Symptoms. You: experience chest discomfort with exertion experience unreasonable breathlessness experience dizziness, fainting or blackouts experience ankle swelling experience unpleasant awareness of a forceful or rapid heart rate take heart medications Other health issues. You: have diabetes have asthma or other lung disease have burning or cramping sensation in your lower legs when walking short distances have musculoskeletal problems that limit your physical activity have concerns about the safety of exercise take prescription medications are pregnant

If you marked any of these statements in this section, consult your GP or other appropriate allied health professional before engaging in exercise. You may need to use a facility with a medically qualified staff.

Cardiovascular risk factors. You: are a man ≥ 45 yr are a woman ≥ 55 yr smoke or quit smoking within the previous six months blood pressure is ≥ 140/90 mmHg do not know your blood pressure take blood pressure medication blood cholesterol level is ≥ 200 mg dL −1 do not know your cholesterol level have a close blood relative who had a heart attack or heart surgery before age 55 (father or brother) or age 65 (mother or sister) are physically inactive (i.e. you get 96

Good

83–96

Average

68–82

Low average

54–67

Poor

2800 m

2400–2800 m

2200–2399 m

1600–2199 m

2700 m

2300–2700 m

1900–2299 m

1500–1999 m

2500 m

2100–2500 m

1700–2099 m

1400–1699 m

50

>2400 m

2000–2400 m

1600–1999 m

1300–1599 m

2700 m

2200–2700 m

1800–2199 m

1500–1799 m

2500 m

2000–2500 m

1700–1999 m

1400–1699 m

2300 m

1900–2300 m

1500–1899 m

1200–1499 m

50

>2200 m

1700–2200 m

1400–1699 m

1100–1399 m

60

>64

>38

>40

Superior

54–49

56–64

33–37

35–39

Excellent

49–53

51–55

29–32

31–34

Above average

45–48

47–50

26–28

28–30

Below average

41–44

43–46

23–25

25–27

Fair