Nutrition for health fitness and sport 11e williams 1

CHAPTER ONE Introduction to Nutrition for Health, Fitness, and Sports Performance 1 CHAPTER TWO Healthful Nutrition for Fitness and Sport: The Consumer Athlete 37 CHAPTER FIVE Fat:

NUTRITION FOR HEALTH, FITNESS AND SPORT: ELEVENTH EDITION

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Names: Williams, Melvin H | Rawson, Eric S | Branch, J David,

1956-Title: Nutrition for health, fitness, and sport / Melvin H Williams, Old

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CHAPTER ONE Introduction to Nutrition for Health, Fitness,

and Sports Performance 1

CHAPTER TWO Healthful Nutrition for Fitness and Sport:

The Consumer Athlete 37

CHAPTER FIVE Fat: An Important Energy Source during Exercise 175

CHAPTER EIGHT Minerals: The Inorganic Regulators 327

CHAPTER ELEVEN Weight Maintenance and Loss through Proper Nutrition

and Exercise 476

CHAPTER TWELVE Weight Gaining through Proper Nutrition and Exercise 539

Brief Contents

Preface xiii

C H A P T E R O N E

Introduction to Nutrition for Health,

Fitness, and Sports Performance 1

Health-Related Fitness: Exercise and Nutrition 4

Exercise and Health-Related Fitness 4

What is health-related fitness? 4

What are the basic principles of exercise training? 4

What is the role of exercise in health promotion? 6

How does exercise enhance health? 6

Do most of us exercise enough? 8

How much physical activity is enough for health benefits? 8

Am I exercising enough? 11

Can too much exercise be harmful to my health? 11

Nutrition and Health-Related Fitness 12

Are there additional health benefits when both exercise and diet

habits are improved? 16

Sports-Related Fitness: Exercise and Nutrition 17

What is sports-related fitness? 17

What is sports nutrition? 18

Is sports nutrition a profession? 18

Are athletes today receiving adequate nutrition? 19

Why are some athletes malnourished? 19

How does nutrition affect athletic performance? 20

What should athletes eat to help optimize sport performance? 20

Ergogenic Aids and Sports Performance: Beyond

Training 21

What is an ergogenic aid? 21

Why are nutritional ergogenics so popular? 22

Are nutritional ergogenics effective? 22

Are nutritional ergogenics safe? 22

Are nutritional ergogenics legal? 23

Where can I find more detailed information on sports

supplements? 23

Nutritional Quackery in Health and Sports 24

What is nutritional quackery? 24

Why is nutritional quackery so prevalent in athletics? 25

How do I recognize nutritional quackery in health and sports? 25

Where can I get sound nutritional information to combat quackery

in health and sports? 26

Research and Prudent Recommendations 27

What types of research provide valid information? 28 Why do we often hear contradictory advice about the effects of nutrition on health or physical performance? 29

What is the basis for the dietary recommendations presented in this book? 30

How does all this relate to me? 31

Application Exercises 32Review Questions—Multiple Choice 32Review Questions—Essay 33

The Balanced Diet and Nutrient Density 42

What is a balanced diet? 42 What foods should I eat to obtain the nutrients I need? 43 What is the MyPlate food guide? 43

What is the Food Exchange System? 45 What is the key-nutrient concept for obtaining a balanced diet? 46

What is the concept of nutrient density? 47 Will using the MyPlate food guide or the Food Exchange System guarantee me optimal nutrition? 49

Healthful Dietary Guidelines 49

What is the basis underlying the development of healthful dietary guidelines? 49

What are the recommended dietary guidelines for reducing the risk of chronic disease? 50

Vegetarianism 56

What types of foods does a vegetarian eat? 56 What are some of the nutritional concerns with a vegetarian diet? 57

Is a vegetarian diet more healthful than a nonvegetarian diet? 59

Contents

How do we measure physical activity and energy expenditure? 92

What is the most commonly used measure of energy? 95

Human Energy Systems 97

How is energy stored in the body? 97 What are the human energy systems? 98 What nutrients are necessary for operation of the human energy systems? 101

Human Energy Metabolism during Rest 102

What is metabolism? 102 What factors account for the amount of energy expended during rest? 102

What effect does eating a meal have on the metabolic rate? 102 How can I estimate my daily resting energy expenditure (REE)? 103

What genetic factors affect my REE? 103 How do dieting and body composition affect my REE? 104 What environmental factors may also influence the REE? 104 What energy sources are used during rest? 104

Human Energy Metabolism during Exercise 105

How do my muscles influence the amount of energy I can produce during exercise? 105

What effect does muscular exercise have on the metabolic rate? 106

How is energy expenditure of the three human energy systems measured during exercise? 106

How can I convert the various means of expressing exercise energy expenditure into something more useful to me, such as Calories per minute? 107

How can I tell what my metabolic rate is during exercise? 109

How can I determine the energy cost of my exercise routine? 109

What are the best types of activities to increase energy expenditure? 110

Does exercise affect my resting energy expenditure (REE)? 111

Does exercise affect the thermic effect of food (TEF)? 112 How much energy should I consume daily? 112

Human Energy Systems and Fatigue during Exercise 115

What energy systems are used during exercise? 115 What energy sources are used during exercise? 116 What is the “fat burning zone” during exercise? 117 What is fatigue? 118

What causes acute fatigue in athletes? 119 How can I delay the onset of fatigue? 120 How is nutrition related to fatigue processes? 120

Application Exercise 122Review Questions—Multiple Choice 122Review Questions—Essay 123

References 123

How can I become a vegetarian? 61

Will a vegetarian diet affect physical performance potential? 62

Consumer Nutrition—Food Labels and Health

Claims 63

What nutrition information do food labels provide? 63

How can I use this information to select a healthier diet? 63

What are the proposed changes to the current food label? 65

What health claims are allowed on food products? 67

What are functional foods? 68

Consumer Nutrition—Dietary Supplements

and Health 69

What are dietary supplements? 69

Will dietary supplements improve my health? 70

Can dietary supplements harm my health? 71

Consumer Nutrition—Food Quality and Safety 72

Is current food biotechnology effective and safe? 72

Do pesticides in food present significant health risks? 73

Are organic foods safer and healthier choices? 74

Does commercial food processing affect food quality and safety? 74

Does home food processing affect food quality and safety? 75

What is food poisoning? 76

Are food additives safe? 77

Why do some people experience adverse reactions to some

foods? 78

Healthful Nutrition: Recommendations for Better

Physical Performance 79

What should I eat during training? 79

When and what should I eat just prior to competition? 80

What should I eat during competition? 81

What should I eat after competition? 81

Should athletes use commercial sports foods? 81

How can I eat more nutritiously while traveling for

competition? 82

How do gender and age influence nutritional recommendations

for enhanced physical performance? 84

What apps are available to help me in my quest to develop

a diet plan to improve both my health and my sports

Carbohydrates: Ergogenic Aspects 159

Do the metabolic by-products of carbohydrate exert an ergogenic effect? 159

Dietary Carbohydrates: Health Implications 161

How do refined sugars and starches affect my health? 161 Are artificial sweeteners safe? 162

Why are complex carbohydrates thought to be beneficial

to my health? 164 Why should I eat foods rich in fiber? 164

Do some carbohydrate foods cause food intolerance? 166 Does exercise exert any beneficial health effects related

to carbohydrate metabolism? 167

Application Exercise 168Review Questions—Multiple Choice 168Review Questions—Essay 169

References 170

C H A P T E R F I V E

Fat: An Important Energy Source during Exercise 175Dietary Fats 176

What are the different types of dietary fats? 176 What are triglycerides? 176

What are some common foods high in fat content? 177 How do I calculate the percentage of fat Calories in a food? 178 What are fat substitutes? 179

What is cholesterol? 180 What foods contain cholesterol? 180 What are phospholipids? 180 What foods contain phospholipids? 181 How much fat and cholesterol do we need in the diet? 181

Metabolism and Function 183

How does dietary fat get into the body? 183 What happens to the lipid once it gets in the body? 183 What are the different types of lipoproteins? 185 Can the body make fat from protein and carbohydrate? 186 What are the major functions of the body lipids? 186 How much total energy is stored in the body as fat? 187

Fats and Exercise 188

Are fats used as an energy source during exercise? 188 Does gender or age influence the use of fats as an energy source during exercise? 189

What effect does exercise training have on fat metabolism during exercise? 190

Fats: Ergogenic Aspects 191

High-fat diets 191 High-fat diets and weight loss 193 Does exercising on an empty stomach or fasting improve performance? 194

C H A P T E R F O U R

Carbohydrates: The Main Energy

Food 125

Dietary Carbohydrates 126

What are the different types of dietary carbohydrates? 126

What are some common foods high in carbohydrate

content? 128

How much carbohydrate do we need in the diet? 129

Metabolism and Function 130

How are dietary carbohydrates digested and absorbed and what

are some implications for sports performance? 130

What happens to the carbohydrate after it is absorbed into the

body? 131

What is the metabolic fate of blood glucose? 132

How much total energy do we store as carbohydrate? 135

Can the human body make carbohydrates from protein

and fat? 136

What are the major functions of carbohydrate in human

nutrition? 136

Carbohydrates for Exercise 138

In what types of activities does the body rely heavily on

carbohydrate as an energy source? 138

Why is carbohydrate an important energy source for

exercise? 138

What effect does endurance training have on carbohydrate

metabolism? 139

How is hypoglycemia related to the development of fatigue? 139

How is lactic acid production related to fatigue? 141

How is low muscle glycogen related to the development of

fatigue? 141

How are low endogenous carbohydrate levels related to the

central fatigue hypothesis? 143

Will eating carbohydrate immediately before or during an event

improve physical performance? 144

When, how much, and in what form should carbohydrates be

consumed before or during exercise? 147

What is the importance of carbohydrate replenishment after

prolonged exercise? 151

Will a high-carbohydrate diet enhance my daily exercise

training? 152

Carbohydrate Loading 154

What is carbohydrate, or glycogen, loading? 154

What type of athlete would benefit from carbohydrate

loading? 154

How do you carbohydrate load? 154

Will carbohydrate loading increase muscle glycogen

concentration? 155

How do I know if my muscles have increased their glycogen

stores? 156

Will carbohydrate loading improve exercise performance? 157

Are there any possible detrimental effects relative to

carbohydrate loading? 158

What are some general recommendations relative to dietary protein intake for athletes? 237

Are protein supplements necessary? 239

Before Sleep Protein Intake 240Protein: Ergogenic Aspects 241

What types of special protein supplements are marketed to physically active individuals? 241

Do high-protein diets or protein supplements increase muscle mass and strength in resistance-trained individuals? 242

Do high-protein diets or protein supplements improve aerobic endurance performance in endurance-trained individuals? 243

Are amino acid, amine, and related nitrogen-containing supplements effective ergogenic aids? 245

Dietary Protein: Health Implications 262

Does a deficiency of dietary protein pose any health risks? 262 Does excessive protein intake pose any health risks? 263 Does the consumption of individual amino acids pose any health risks? 265

Application Exercise 266Review Questions—Multiple Choice 266Review Questions—Essay 267

Water-Soluble Vitamins 291

Thiamin (vitamin B 1 ) 291 Riboflavin (vitamin B 2 ) 292 Niacin 293

Vitamin B 6 (pyridoxine) 294 Vitamin B 12 (cobalamin) 295 Folate (folic acid) 296 Pantothenic acid 297 Biotin 298

Choline 298 Vitamin B complex 299 Vitamin C (ascorbic acid) 300

Can the use of medium-chain triglycerides improve endurance

performance or body composition? 194

Is the glycerol portion of triglycerides an effective

ergogenic aid? 195

Are phospholipid dietary supplements effective

ergogenic aids? 195

Omega-3 fatty acid and fish oil supplements 196

Can carnitine improve performance or weight loss? 197

Can hydroxycitrate (HCA) enhance endurance performance? 198

Can conjugated linoleic acid (CLA) enhance exercise

performance or weight loss? 198

What’s the bottom line regarding the ergogenic effects of fat

burning diets or strategies? 198

Dietary Fats and Cholesterol: Health Implications 199

How does cardiovascular disease develop? 199

How do the different forms of serum lipids affect the

development of atherosclerosis? 201

Can I reduce my serum lipid levels and possibly reverse

atherosclerosis? 203

What should I eat to modify my serum lipid profile favorably? 204

Can exercise training also elicit favorable changes in the serum

Is there a difference between animal and plant protein? 225

What are some common foods that are good sources of

protein? 226

How much dietary protein do I need? 226

How much of the essential amino acids do I need? 228

What are some dietary guidelines to ensure adequate protein

intake? 228

Metabolism and Function 229

What happens to protein in the human body? 229

Can protein be formed from carbohydrates and fats? 230

What are the major functions of protein in human nutrition? 231

Proteins and Exercise 232

Are proteins used for energy during exercise? 232

Does exercise increase protein losses in other ways? 234

What happens to protein metabolism during recovery after

Vitamin Supplements: Ergogenic Aspects 302

Should physically active individuals take vitamin

Vitamin Supplements: Health Aspects 308

Can I obtain the vitamins I need through my diet? 308

Why are vitamin supplements often recommended? 308

Why do individuals take vitamin megadoses? 310

Do foods rich in vitamins, particularly antioxidant vitamins, help

deter chronic disease? 310

Do vitamin supplements help deter disease? 311

How much of a vitamin supplement is too much? 314

If I want to take a vitamin-mineral supplement, what are some

What are minerals, and what is their importance to humans? 328

What minerals are essential to human nutrition? 329

In general, how do deficiencies or excesses of minerals influence

health or physical performance? 329

Other Trace Minerals 358

Mineral Supplements: Exercise and Health 360

Does exercise increase my need for minerals? 360

Can I obtain the minerals I need through my diet? 360

Are mineral megadoses or some nonessential minerals harmful? 361

Should physically active individuals take mineral supplements? 362

Application Exercise 363Review Questions—Multiple Choice 363Review Questions—Essay 364

Electrolytes 378

What is an electrolyte? 378 Sodium (Na) 378

Chloride (Cl) 380 Potassium (K) 380

Regulation of Body Temperature 381

What is the normal body temperature? 381 What are the major factors that influence body temperature? 382

How does the body regulate its own temperature? 382 What environmental conditions may predispose an athletic individual to hyperthermia? 383

How does exercise affect body temperature? 384 How is body heat dissipated during exercise? 385

Exercise Performance in the Heat: Effect

of Environmental Temperature and Fluid and Electrolyte Losses 385

How does environmental heat affect physical performance? 386 How do dehydration and hypohydration affect physical

performance? 387 How fast may an individual dehydrate while exercising? 389 How can I determine my sweat rate? 389

What is the composition of sweat? 390

Is excessive sweating likely to create an electrolyte deficiency? 390

Exercise in the Heat: Fluid, Carbohydrate, and Electrolyte Replacement 390

Which is most important to replace during exercise in the heat—water, carbohydrate, or electrolytes? 391

What are some sound guidelines for maintaining water (fluid)

balance during exercise? 391

What factors influence gastric emptying and intestinal

What is hyponatremia and what causes it during exercise? 396

Are salt tablets or potassium supplements necessary? 398

What are some prudent guidelines relative to fluid replacement

while exercising under warm or hot environmental

conditions? 398

Ergogenic Aspects 402

Does oxygen water enhance exercise performance? 403

Do pre-cooling techniques help reduce body temperature and

enhance performance during exercise in the heat? 403

Does sodium loading enhance endurance performance? 403

Does glycerol supplementation enhance endurance

performance during exercise under warm environmental

conditions? 404

Health Aspects: Heat Illness 406

Should I exercise in the heat? 406

What are the potential health hazards of excessive heat stress

imposed on the body? 406

What are the symptoms and treatment of heat injuries? 409

Do some individuals have problems tolerating exercise in the

heat? 409

How can I reduce the hazards associated with exercise in a hot

environment? 411

How can I become acclimatized to exercise in the heat? 412

Health Aspects: High Blood Pressure 413

What is high blood pressure, or hypertension? 413

How is high blood pressure treated? 413

What dietary modifications may help reduce or prevent

Body Weight and Composition

for Health and Sport 428

Body Weight and Composition 430

What is the ideal body weight? 430

What are the values and limitations of the BMI? 431

What is the composition of the body? 431

What techniques are available to measure body composition and how accurate are they? 433

What problems may be associated with rigid adherence to body fat percentages in sport? 438

How much should I weigh or how much body fat should I have? 438

Regulation of Body Weight and Composition 440

How does the human body normally control its own weight? 440 How is fat deposited in the body? 444

What is the cause of obesity? 444 Can the set point change? 449 Why is prevention of childhood obesity so important? 449

Weight Gain, Obesity, and Health 451

What health problems are associated with overweight and obesity? 451

How does the location of fat in the body affect health? 453 Does being obese increase health risks in youth? 455 Does losing excess body fat reduce health risks and improve health status? 455

Does being physically fit negate the adverse health effects associated with being overweight? 455

Excessive Weight Loss and Health 457

What health problems are associated with improper weight-loss programs and practices? 457

What are the major eating disorders? 459 What eating problems are associated with sports? 461

Body Composition and Physical Performance 464

What effect does excess body weight have on physical performance? 464

Does excessive weight loss impair physical performance? 465

Application Exercise 466Review Questions—Multiple Choice 466Review Questions—Essay 467

References 467

C H A P T E R E L E V E N

Weight Maintenance and Loss through Proper Nutrition and Exercise 476

Basics of Weight Control 478

How many Calories are in a pound of body fat? 478

Is the caloric concept of weight control valid? 479 How many Calories do I need per day to maintain my body weight? 479

How much weight can I lose safely per week? 483 How can I determine the amount of body weight I need to lose? 483

Behavior Modification 484

What is behavior modification? 484

How do I apply behavior-modification techniques in my

Why does a person usually lose the most weight during the first

week on a reducing diet? 489

Why does it become more difficult to lose weight after several

weeks or months on a diet program? 490

What are the major characteristics of a sound diet for weight

control? 490

Is it a good idea to count Calories when attempting to lose body

weight? 493

How often should i weigh myself? 494

What is the Food Exchange System? 494

How can I determine the number of Calories I eat daily? 495

What are some general guidelines I can use in the selection

and preparation of foods to promote weight loss or

maintain a healthy body weight? 497

How can I plan a nutritionally balanced, low-Calorie

diet? 501

Are very low-Calorie diets effective and desirable as a means to

lose body weight? 504

Are weight-loss dietary supplements effective and safe? 504

Is it harmful to overeat occasionally? 506

Exercise Programs 506

What role does exercise play in weight reduction and weight

maintenance? 506

Does exercise affect the appetite? 508

Does exercise affect the set point? 509

What types of exercise programs are most effective for losing

What is the stimulus period of exercise? 515

What is an appropriate level of exercise intensity? 515

How can I determine the exercise intensity needed to achieve my

target HR range? 519

How can I design my own exercise program? 519

How much exercise is needed to lose weight? 522

From what parts of the body does the weight loss occur during an

exercise weight-reduction program? 523

Should I do low-intensity exercises to burn more fat? 523

Is spot reducing effective? 524

Is it possible to exercise and still not lose body weight? 525

What about the 5 or 6 pounds a person may lose during

an hour of exercise? 526

Comprehensive Weight Control Programs 526

Which is more effective for weight control—dieting or exercise? 526

If I want to lose weight through a national or local weight-loss program, what should I look for? 527

What type of weight-reduction program is advisable for young athletes? 529

What is the importance of prevention in a weight-control program? 529

Application Exercise 531Review Questions—Multiple Choice 531Review Questions—Essay 532

References 532

C H A P T E R T W E L V E

Weight Gaining through Proper Nutrition and Exercise 539Basic Considerations 541

Why are some individuals underweight? 541 What steps should I take if I want to gain weight? 541

Nutritional Considerations 542

How many Calories are needed to form 1 pound of muscle? 542 How can I determine the amount of Calories I need daily to gain 1 pound per week? 542

Is protein supplementation necessary during a weight-gaining program? 542

Are dietary supplements necessary during a weight-gaining program? 544

What is an example of a balanced diet that will help me gain weight? 545

Would such a high-Calorie diet be ill advised for some individuals? 545

Exercise Considerations 546

What are the primary purposes of resistance training? 547 What are the basic principles of resistance training? 547 What is an example of a resistance-training program that may help me to gain body weight as lean muscle mass? 550 Are there any safety concerns associated with resistance training? 551

How does the body gain weight with a resistance-training program? 555

Is any one type of resistance-training program or equipment more effective than others for gaining body weight? 557

If exercise burns Calories, won’t I lose weight on a training program? 557

resistance-Are there any contraindications to resistance training? 558 Are there any health benefits associated with resistance training? 558

Can I combine aerobic and resistance-training exercises into one program? 559

Alcohol: Ergogenic Effects and Health Implications 567

What is the alcohol and nutrient content of typical alcoholic

beverages? 567

What is the metabolic fate of alcohol in the body? 567

Is alcohol an effective ergogenic aid? 568

What effect can drinking alcohol have upon my health? 570

Caffeine: Ergogenic Effects and Health Implications 576

What is caffeine, and in what food products is it found? 576

What effects does caffeine have on the body that may benefit

exercise performance? 576

Does caffeine enhance exercise performance? 577

Does drinking coffee, tea, or other caffeinated beverages provide

any health benefits or pose any significant health risks? 581

Ephedra (Ephedrine): Ergogenic Effects and Health

Implications 585

What is ephedra (ephedrine)? 585

Does ephedrine enhance exercise performance? 585

Do dietary supplements containing ephedra pose any health

risks? 585

Sodium Bicarbonate: Ergogenic Effects, Safety, and

Legality 587

What is sodium bicarbonate? 587

Does sodium bicarbonate, or soda loading, enhance physical

performance? 587

Is sodium bicarbonate supplementation safe and legal? 589

Anabolic Hormones and Dietary Supplements: Ergogenic

Effects and Health Implications 590

Is human growth hormone (HGH) an effective, safe, and legal

What herbals are effective ergogenic aids? 596

Sports Supplements: Efficacy, Safety, and Permissibility 598

What sports supplements are considered to be effective, safe, and permissible? 598

Application Exercise 599Review Questions—Multiple Choice 599Review Questions—Essay 600

APPENDIX C Determination of Healthy Body Weight 614

APPENDIX D Exchange Lists for Meal Planning 619

APPENDIX E Nutrient Content of Food Products from Selected Fast-Food Restaurants 631

APPENDIX F Energy Pathways of Carbohydrate, Fat, and Protein 633

APPENDIX G Sample Menu for a 2,000-Calorie Food Pattern 637

Glossary 641Photo Credits 665Index 666

According to the World Health Organization, better health is the

key to human happiness and well-being Many factors influence

one’s health status, including some provided by various

govern-ment and health agencies, such as safe living environgovern-ments and

access to proper health care However, in general, one’s personal

health over the course of a lifetime is dependent more on personal

lifestyle choices, two of the most important being proper exercise

and healthy eating

In the twenty-first century, our love affair with fitness and sports

continues to grow Worldwide, although physical inactivity is still

very prevalent in developed nations, more of us are joining fitness

facilities or initiating fitness programs, such as bicycling, running,

swimming, walking, and weight training Improvement in health

and fitness is one of the major reasons that more and more

peo-ple initiate an exercise program, but many may also become more

interested in sports competition, such as age-group road racing;

running and walking race competitions have become increasingly

popular, and every weekend numerous road races can be found

within a short drive Research has shown that adults who become

physically active also may become more interested in other aspects

of their lifestyles—particularly nutrition—that may affect their

health in a positive way Indeed, according to all major health

orga-nizations, proper exercise and a healthful diet are two of the most

important lifestyle behaviors to help prevent chronic disease

Nutrition is the study of foods and their effects upon health,

development, and performance Over the years, nutrition research

has made a significant contribution to our knowledge of essential

nutrient needs During the first part of the twentieth century, most

nutrition research focused on identification of essential

nutri-ents and amounts needed to prevent nutrient-deficiency diseases,

such as scurvy from inadequate vitamin C As nutrition science

evolved, medical researchers focused on the effects of foods and

their specific constituents as a means to help prevent the major

chronic diseases, such as heart disease and cancer, that are

epi-demic in developed countries Nutriceutical is a relatively new

term used to characterize the drug, or medical, effects of a

par-ticular nutrient Recent research findings continue to indicate that

our diet is one of the most important determinants of our health

status Although individual nutrients are still being evaluated

for possible health benefits, research is also focusing on dietary

patterns, or the totality of the diet, and resultant health benefits

However, we should note that research relative to the effects of

diet, including specific nutrients, on health is complex and dietary

recommendations may change with new research findings For example, as shall be noted later in the text, the guidelines regard-ing dietary intake of cholesterol have been modified after being in effect for more than 50 years

Other than the health benefits of exercise and fitness, many physically active individuals also are finding the joy of ath-letic competition, participating in local sports events such as golf tournaments, tennis matches, triathlons, and road races Individuals who compete athletically are always looking for a means to improve performance, be it a new piece of equipment

or an improved training method In this regard, proper nutrition may be a very important factor in improving sports performance Various sports governing agencies indicate today’s athletes need accurate sports nutrition information to maximize sports perfor-mance Although the effect of diet on sports and exercise perfor-mance was studied only sporadically prior to 1970, subsequently numerous sports scientists and sports nutritionists have studied the performance-enhancing effects of nutrition, such as diet com-position and dietary supplements Results of these studies have provided nutritional guidance to enhance performance in specific athletic endeavors In the United States, many universities and pro-fessional sports teams, such as those in Major League Baseball and the National Football League, employ registered dietitians as well

as culinary chefs to provide dietary guidance to their athletes.With the completion of the Human Genome Project, gene therapies are being developed for the medical treatment of various health problems Moreover, some contend that genetic manipula-tions may be used to enhance sports performance For example, gene doping to increase insulin-like growth factor, which can stimulate muscle growth, may be applied to sport

Our personal genetic code plays an important role in ing our health status and our sports abilities, and futurists specu-late that one day each of us will carry our own genetic chip that will enable us to tailor food selection and exercise programs to optimize our health and sports performance Such may be the case, but for the time being we must depend on available scientific evi-dence to provide us with prudent guidelines

determin-Each year thousands of published studies and reviews analyze the effects of nutrition on health or exercise and sports perfor-mance The major purpose of this text is to evaluate these scien-tific data and present prudent recommendations for individuals who want to modify their diet for optimal health or exercise/sports performance

Preface

and clarity, such as the use of bullet points to summarize key points More than 700 new references, including clinical studies, reviews, and meta-analyses, have been added to the text Major

changes include incorporation of the new Dietary Guidelines

for Americans. The MyPlate model is designed to be more user friendly for the American population and is discussed in several chapters New information from authoritative position statements dealing with exercise and nutrition issues has been incorporated into various chapters where relevant These position statements have been developed by such prominent groups as the Academy of Nutrition and Dietetics, the American College of Sports Medicine, the American Academy of Pediatrics, the American Heart Association, the American College of Cardiology, the European College of Sport Science, the European Food Safety Authority, and Sports Dietitians Australia Additionally, numerous Websites have been listed to help students explore various exercise and nutrition issues in more depth

Chapter 1—Introduction to Nutrition for Health, Fitness, and Sports Performance

∙ New information on the use of various applications for health promotion

∙ Increased discussion of the use of various exercise gadgets, such as fitness bands and fitness watches, to help document daily amounts of physical activity and other aspects of lifestyle

∙ Update on the role of exercise to enhance health

∙ Introduction of high-intensity interval training (HIIT) and its possible application to exercise for health

∙ Introduction of the Compendium of Physical Activities, which

is used in various chapters referring to energy expenditure ing physical activities

dur-∙ Increased use of reputable Websites to provide more detailed information on exercise and diet for health

∙ Discussion of new position stands, as related to a healthy diet

by the Academy of Nutrition and Dietetics, the new name for the American Dietetic Association

∙ Introduction to the 2015 Dietary Guidelines for Americans, the

most recent report of the 2015 Dietary Guidelines Advisory Committee

∙ New application exercise for diet appraisal using several Website-based diet analyses by the Academy of Nutrition and Dietetics and other health profession groups

∙ Over 40 new references added and numerous dated citations deleted

Chapter 2—Healthful Nutrition for Fitness and Sport: The Consumer Athlete

∙ Updated discussion of dietary guidelines, including the debate over research with saturated fatty acids and the proposed new guidelines for cholesterol

∙ Introduction to the Academy of Nutrition and Dietetics position stand on the total diet approach to healthy eating

∙ Discussion of several smartphone applications (apps) to help you eat a healthier diet

∙ More details on how to use the MyPlate program to plan a healthier diet

Textbook Overview

This book uses a question-answer approach, which is convenient

when you may have occasional short periods to study, such as

rid-ing a bus or durrid-ing a lunch break In addition, the questions are

arranged in a logical sequence, the answer to one question often

leading into the question that follows Where appropriate,

cross-referencing within the text is used to expand the discussion No

deep scientific background is needed for the chemical aspects of

nutrition and energy expenditure, as these have been simplified

Instructors who use this book as a course text may add details of

biochemistry as they feel necessary

Chapter 1 introduces you to the general effects of exercise and

nutrition on health-related and sports-related fitness, including the

importance of well-controlled scientific research Chapter 2

pro-vides a broad overview of sound guidelines relative to nutrition

for optimal health and physical performance Chapter 3 focuses

on energy and energy pathways in the body, the key to all exercise

and sports activities

Chapters 4 through 9 deal with the six basic nutrients—

carbohydrate, fat, protein, vitamins, minerals, and water—with

emphasis on the health and performance implications for the

phys-ically active individual Chapters 10 through 12 review concepts

of body composition and weight control, with suggestions on how

to gain or lose body weight through diet and exercise, as well as

the implications of such changes for health and athletic

perfor-mance Chapter 13 covers several drug foods, such as alcohol and

caffeine, and other related dietary supplements regarding their

effects on health and exercise performance Several appendixes

complement the text, providing data on caloric expenditure during

exercise; detailed metabolic pathways for carbohydrate, fat, and

protein; methods to determine body composition; nutritional value

of fast foods; and other information pertinent to physically active

individuals

New to the Eleventh Edition

The first edition of this textbook, titled Nutrition for Fitness and

Sport, was published in 1983 I am joined in this eleventh edition

by two professors who are actively involved in the disciplines

of exercise physiology and sports nutrition, and who have used

this text over the years to teach their university classes J David

Branch is an associate professor in the Department of Human

Movement Sciences at Old Dominion University in Virginia

His e-mail address is dbranch@odu.edu Eric Rawson is a

pro-fessor in the Department of Exercise Science at Bloomsburg

University in Pennsylvania His e-mail address is erawson@

bloomu.edu Dr Branch revised chapters 6, 9, 10, 11, 12, and

13; Dr Rawson revised chapters 4, 5, and 6; and I revised

chapters 1, 2, 3, and 8

The content throughout each chapter of the book has been

updated, where merited, based on contemporary research

find-ings regarding the effects of nutritional practices on health,

fit-ness, and sports performance Many sections throughout the text

were completely rewritten in attempts to improve presentation

∙ New data on the effects of protein plus carbohydrate ingestion

on acute and repeated endurance exercise performance

∙ The latest protein intake recommendations on postexercise and before-sleep protein supplementation

∙ Update on the importance of dietary protein in satiety and weight loss

∙ Newest data on the safety of high protein intakes

∙ New data on creatine supplementation and muscle strength

∙ Latest information on beta-alanine supplementation

∙ Updated information on the effectiveness of HMB supplementation

∙ Update on the role of beetroot/nitrate ingestion on endurance exercise performance

∙ Over 20 new references

Chapter 7—Vitamins: The Organic Regulators

∙ New data on deficiency prevalence rates for folate and vitamins

B6, D, B12, A, C, and E

∙ New information on vitamin D status, deficiency, and mentation in athletes

supple-∙ New information on vitamin E status and exercise performance

∙ New information on the effects of certain medications on min B12 deficiency

vita-∙ New information on pantothenic acid and choline tation and performance

supplemen-∙ Link to current comments from the American College of Sports Medicine regarding vitamin/mineral supplementation and exercise

∙ New information on the role of antioxidant supplementation in the older athlete

∙ New reviews on the ergogenic effects of coenzyme Q10 and quercetin

∙ New studies of the role of vitamin B supplementation on cysteine levels and primary and secondary stroke prevention

homo-∙ New information on vitamin supplementation and the ment of age-related macular degeneration and cataracts

manage-∙ New information on the roles of antioxidant vitamins and min D in mental health

vita-∙ Over 50 new references

Chapter 8—Minerals: The Inorganic Regulators

∙ New information on who may be at risk for calcium deficiency

∙ New data on research involving the ergogenic aspects of phosphate salt supplementation, including new studies and reviews

∙ New information on all trace minerals, including iron, zinc, copper, chromium, and others

∙ New section on manganese as a trace mineral

∙ New discussion of the metal hypothesis of Alzheimer’s ease, which suggests some minerals may be protective but oth-ers may increase the risk

dis-∙ Over 100 new references

Chapter 9—Water, Electrolytes, and Temperature Regulation

∙ Extensive revision to introduction and other parts of the text

∙ Several revised or new figures

∙ Updated information on U.S and global sodium intake

∙ How to become an ambassador for ChooseMyPlate and healthy

eating on your college campus

∙ Presentation of the Harvard Medical School modified MyPlate

to present more specific recommendations for healthy eating

∙ Discussion of the proposed new food labels designed to make

food shopping easier to select healthier foods

∙ An update on the controversy concerning use of GMO foods

∙ Use of various Websites to stay current, such as fruits and

veg-etables that fall into those with the lowest and highest pesticide

content

∙ Over 40 new references, most of them reviews and meta-analyses

Chapter 3—Human Energy

∙ Enhanced discussion of techniques to measure energy

expendi-ture, including the use of various commercial apps

∙ Presentation of more details on the use of the MET system to

measure energy expenditure

∙ Presentation of a link to calculate your daily energy

expendi-ture via five methods

∙ Over 30 new references

Chapter 4—Carbohydrates: The Main Energy Food

∙ Updated information on the role of the glycemic index in the

risk of cardiovascular disease

∙ New data on the effectiveness of carbohydrate mouthrinse on

endurance exercise performance

∙ New information on the effects of carbohydrate

supplementa-tion on exercise performance

∙ Updated information on the role of carbohydrate ingestion and

resistance training

∙ New data on the effects of cycling carbohydrate intake on

train-ing adaptations and performance

∙ Update on approved sugar substitutes and artificial sweeteners

and the effects on performance and weight gain

∙ Latest data on the effects of dietary fiber on morbidity and

mortality

∙ Over 20 new references

Chapter 5—Fat: An Important Energy Source during Exercise

∙ Update on the effect of saturated fat on health

∙ New data on the effects of conjugated linoleic acid

supplemen-tation on body composition

∙ Update on the effects of omega fatty acid consumption on disease

∙ New data on avocado intake and cardiovascular health

∙ New research on the effects of dietary medium-chain

triglycer-ides on weight loss and body composition

∙ Update on the effects of ketogenic diets on satiety and appetite

∙ Updated information on low-carbohydrate diets and weight loss

∙ Discussion of the potential effects of high-fat diets in

endur-ance athletes

∙ Update on fasting and endurance exercise performance

∙ Over 20 new references

Chapter 6—Protein: The Tissue Builder

∙ Updated data on the effects of protein supplements on muscle

mass, strength, and power

∙ New information on the effects of protein supplements on

mus-cle damage, soreness, and recovery

∙ New and revised figures throughout the chapter

∙ Incorporation of the Compendium of Physical Activities, which lists MET intensity values of many leisure and recre-ational activities as well as activities of daily living

∙ Discussion of the conversion of MET values into caloric diture to complement appendix B

expen-∙ Incorporating the energy expenditure based on MET ues from the Compendium with Physical Activity Levels and Coefficients in the National Academy of Sciences Estimated Energy Requirement formulas

val-∙ Inclusion of a web link to 171 small steps to a healthier diet and increased physical activity

∙ Inclusion of the proposed requirement by the U.S Food and Drug Administration to include “added sugars” on Nutrition Facts labeling

∙ Inclusion of selected Websites listing caloric and nutritive value of fast-food restaurant foods to complement appendix E

∙ Inclusion of the current list of risk factors and tom of possible disease according to the American College of Sports Medicine

signs/symp-∙ Discussion of high-intensity interval training (HIIT) as

a physical activity component of weight loss and weight maintenance

∙ Expanded discussion and figure for the “fat burning” myth in the selection of exercise intensity for fat loss and weight loss

∙ Recent studies comparing the efficacy of commercial loss programs

weight-∙ Over 90 new references

Chapter 12—Weight Gaining through Proper Nutrition and Exercise

∙ Updated Healthy People 2020 information on the prevalence of

resistance training among U.S adults

∙ Added information on the importance of the branch-chain amino acid leucine in muscle growth

∙ New research on the effects of resistance training in the older adult

∙ New research on the efficacy of creatine supplementation bined with resistance training in the older adult

com-∙ Additional information on regulatory factors and cell signaling pathways in adaptations to resistance training

∙ New research on nutrient timing to facilitate postexercise cle growth

mus-∙ Revised sample weekly resistance training record sheet

∙ New research on the potential efficacy of higher protein intake

in maintaining lean mass and reducing fat mass

∙ Over 20 new references

Chapter 13—Food Drugs and Related Supplements

∙ Revised figures throughout the chapter

∙ Updated World Health Organization data on the global effects

of alcohol abuse on health and mortality

∙ Information on potential interactions between alcohol and prescribed pharmacological agents, especially in older adults

∙ Information on a potential role of coffee in decreasing holic cirrhosis

alco-∙ A link to recent alcohol-impaired traffic safety data

∙ Updated discussion of theoretical mechanisms of heat-related

central nervous fatigue

∙ Updated information on glycerol’s status as a WADA banned

substance

∙ Updated U.S and global prevalence rates for hypertension

∙ Updated information on evolving guidelines for dietary sodium

intake

∙ Over 70 new references

Chapter 10—Body Weight and Composition for Health and Sport

∙ Several revised or new figures

∙ Updated global prevalence rates for obesity

∙ New photograph of bioelectrical impedance procedure for

body-composition assessment

∙ Inclusion of BMI categories representing apparent chronic

energy deficiency

∙ Inclusion of body fat categories by gender and age, modified

from American College of Sports Medicine’s Guidelines for

Exercise Testing and Prescription, 9th edition, and The Cooper

Institute, Dallas, Texas

∙ Updated discussion of brown adipose tissue

∙ Updated discussion of non-exercise activity thermogenesis

(NEAT)

∙ Updated discussion of genetic contributions to obesity from

genome-wide association studies (GRAS)

∙ Discussion of socioeconomic factors contributing to energy

balance, such as more fast-food restaurants and unhealthy food

choices in low-income areas

∙ New information on Calories consumed as sugar-sweetened

beverages

∙ Expanded discussion of stress, environmental, viral exposure,

and epigenetic factors and the built environment as contributors

to obesity

∙ Discussion of the role of disruptions of normal intestinal

bacte-ria in obesity

∙ Discussion of models other than the set-point theory as

theo-retical regulators of energy balance

∙ Expanded discussion of “screen-based” behaviors in impacting

energy expenditure (sedentary activity) and intake

(advertise-ments for energy-dense foods) in children and adults

∙ Expanded discussion of the health impacts of obesity to include

increased risk for Alzheimer’s disease and other dementia

∙ Updated information on prescription weight-loss drugs

approved by the U.S Food and Drug Administration

∙ Updated information reflecting the four clinical eating disorders

currently described in the American Psychiatric Association’s

Diagnostic and Statistical Manual of Mental Disorders —V

∙ Discussion of the controversy surrounding replacing the term

“female athlete triad” with “relative energy deficiency in sport

(RED-S)”

∙ Over 140 new references

Chapter 11—Weight Management and Loss through Proper

Nutrition and Exercise

∙ New information on a gastric stimulation device approved by

the U.S Food and Drug Administration

as a studying guide Key Terms also are listed at the beginning

of each chapter, along with the page number on which they are first highlighted and defined Although some terms may appear

in the text before they are defined, a thorough glossary includes

the key terms as well as other terms warranting definition Key Concepts provide a summary of essential information presented

throughout each chapter Students are encouraged to participate

in several practical activities to help reinforce learning Check for Yourself includes individual activities, such as checking

food labels at the supermarket or measuring one’s own body fat

percentage The Application Exercise at the end of each

chap-ter may require more extensive involvement, such as a case study

in weight control involving yourself or a survey of an athletic team Students may wish to peruse all application exercises at the beginning of the course, as some may take several weeks or months to complete

The reference lists have been completely updated for this tion, with the inclusion of more than 700 new references, and pro-vide the scientific basis for the new concepts or additional support for those concepts previously developed These references pro-vide greater in-depth reading materials for the interested student Although the content of this book is based on appropriate scientific studies, a reference-citation style is not used, that is, each statement

edi-is not referenced by a bibliographic source However, names of authors may be used to highlight a reference source where deemed appropriate

This book is designed primarily to serve as a college text in professional preparation programs in health and physical edu-cation, exercise science, athletic training, sports medicine, and sports nutrition It is also directed to the physically active indi-vidual interested in the nutritional aspects of physical and athletic performance

Those who desire to initiate a physical training program may also find the nutritional information useful, as well as the guide-lines for initiating a training program This book may serve as a handy reference for coaches, trainers, and athletes With the tre-mendous expansion of youth sports programs, parents may find the information valuable relative to the nutritional requirements of their active children

In summary, the major purpose of this book is to help provide

a sound knowledge base relative to the role that nutrition, mented by exercise, may play in the enhancement of both health and sports performance We hope that the information provided

comple-in this text will help the reader develop a more healthful and performance-enhancing diet Bon appetit!

Acknowledgments

This book would not be possible without the many medical/health scientists and exercise/sports scientists throughout the world who, through their numerous studies and research, have provided the scientific data that underlie its development We are fortunate to have developed a friendship with many of you, and we extend our sincere appreciation to all of you

∙ Updated data on the health, academic, and psychological

effects of alcohol in high school and college students

∙ Updated information from studies by the World Cancer

Research Fund (WCRF)/ American Institute of Cancer Research

(AICR) and the International Agency for Research of Cancer

(IARC) on the link between alcohol and breast and other cancers

∙ Discussion of American Psychiatric Association’s Diagnostic

and Statistical Manual of Mental Disorders —V alcohol use

disorder (AUD) diagnosis

∙ Links to online screening questionnaires for possible alcohol

use disorder

∙ New information on the association of alcohol and Alzheimer’s

disease, mental health, and cognitive function

∙ Updated information on the role of alcohol and other

ingredi-ents in alcoholic drinks (e.g., polyphenols) on lipid

metabo-lism, vascular function

∙ Research on the role of genetic variants in alcohol

dehydroge-nase in cardiovascular disease risk

∙ Updated data on the prevalence of coffee/caffeine use in the

United States

∙ Updated information on the prevalence of energy drink use

and concerns about the use of such products that also contain

alcohol

∙ Updated research on the role of coffee/caffeine consumption

and blood pressure and cardio-metabolic health

∙ Updated research on the role of coffee/caffeine in mental

health, cognitive function, and multiple sclerosis

∙ Updated information on caffeine use in pregnancy and in infant

health

∙ Updated information in recent discovery of amphetamine

iso-mers in over-the-counter dietary supplements

∙ Updated status of pseudoephedrine (in addition to ephedrine,

ephedra, and ma huang) as substances that are prohibited for

use in competition by the WADA

∙ Updated information on U.S Food and Drug Administration–

mandated warnings about testosterone replacement therapy and

increased risk for heart attacks and strokes

∙ Updated Centers for Disease Control and Prevention data on

the prevalence of steroid use by teenagers

∙ Updated information on the efficacy of various herbals in

improving body composition or performance

∙ Updated Australian Institute of Sports Classification System of

Nutritional Supplements

∙ Over 110 new references

Appendices

∙ Updated several appendices, including those dealing with

energy expenditure during exercise and the nutrient

composi-tion of products sold in fast-food restaurants

Enhanced Pedagogy

Each chapter contains several features to help enhance the

learn-ing process Chapter Learnlearn-ing Objectives are presented at the

beginning of each chapter, highlighting the key points and serving

MH Campus ® integrates all of your digital products from McGraw—

Hill Education with your school LMS for quick and easy access to best—in—class content and learning tools

Fueled by LearnSmart—the most widely used and intelligent adap-tive learning resource—

LearnSmart Prep ® is designed to get students ready for a forthcoming course by quickly and effectively addressing prereq-uisite knowledge gaps that may cause problems down the road

Inspire behavior change

NutritionCalc Plus is an

online suite of powerful dietary self—assessment tools that help students track their food intake and activity and analyze their diet and health goals

Students and instructors can trust the reliability of the ESHA database while interacting with a robust selection of reports

We would like to acknowledge deep gratitude to Mandy Clark,

Product Developer at McGraw-Hill, for her dedicated support

throughout the revision process Mandy was always available to

address queries regarding various facets of the production process,

and her responses were very prompt We would also like to thank

Anna Hoppmann, Digital Asset Librarian, for her assistance in

navigating the photo database of McGraw-Hill, and Jessica Portz,

our project manager Our deep gratitude to Marija Magner, Brand

Manager

Melvin H Williams

Norfolk, Virginia

J David Branch Norfolk, Virgina Eric S Rawson

Bloomsburg, Pennsylvania

Instructor Resources

Available at www.mhhe.com/williams11e are a number of

instruc-tor and student resources to accompany the text For students, these

include a BMI calculator, animations, daily food log, and more

For instructors, resources include PPT lecture outlines, image

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C H A P T E R O N E

nutrition 12physical activity 4physical fitness 4promoters 13Prudent Healthy Diet 15quackery 24

risk factor 2Sedentary Death Syndrome (SeDS) 6sports nutrition 18

sports-related fitness 17sports supplements 22structured physical activity 4unstructured physical activity 4

Introduction to

Nutrition for Health,

Fitness, and Sports

Performance

L E A R N I N G O B J E C T I V E S

After studying this chapter, you should be able to:

1. Explain the role of both genetics and environment, particularly nutrition

and exercise, in the determination of optimal health and successful sport

performance

2. List each of the components of health-related fitness and then identify the

potential health benefits of an exercise program designed to enhance both

aerobic and musculoskeletal fitness

3. Define sports-related fitness and compare it to health-related fitness, noting

similarities and differences

4. List the seven principles of exercise training and explain the importance of

each

5. List the 12 guidelines underlying the Prudent Healthy Diet and discuss, in

general, the importance of proper nutrition to optimal health

6. Understand the importance of proper nutrition, including the role of dietary

supplements as ergogenic aids, to sports performance

7. Define nutritional quackery and understand the various strategies you can

use to determine whether claims regarding a dietary supplement are valid

8. Explain what types of research have been used to evaluate the relationship

between nutrition and health or sport performance, and evaluate the pros

and cons of each type

K E Y T E R M S

antipromoters 13cytokines 7doping 23epidemiological research 28epigenetics 2

epigenome 2ergogenic aids 21exercise 4experimental research 28health-related fitness 4high-intensity interval training (HIIT) 9malnutrition 20

meta-analysis 30nutrient 12

I n t r o d u c t i o n

There are two major focal points of this book One is the role that nutrition, complemented by

physi-cal activity and exercise, may play in the enhancement of one’s health status The other is the role that

nutrition may play in the enhancement of fitness and sports performance Many individuals today are

physically active, and athletic competition spans all ages Healthful nutrition is important throughout

the life span of the physically active individual because suboptimal health status may impair training

and competitive performance In general, as we shall see, the diet that is optimal for health is also

optimal for exercise and sports performance.

Nutrition, fitness, and health. Health

care in most developed countries has

improved tremendously over the past

century Although some rather rare

diseases, such as Ebola, are a cause for

concern, primarily because of the

dedi-cated work of medical researchers we no

longer fear the scourge of major acute

infectious diseases such as polio,

small-pox, or tuberculosis However, we have

become increasingly concerned with

the treatment and prevention of chronic

diseases The World Health Organization

(WHO) indicates that chronic diseases

are now the major cause of death and

disability worldwide According to the

U.S Department of Health and Human

Services (HHS), unhealthy eating and

physical inactivity are leading causes of

death in the United States Given with

rank in parentheses, they include (1)

dis-eases of the heart, (2) cancer, (3) stroke,

(4) chronic lung diseases, (6) diabetes,

(8) Alzheimer’s disease, and (9) chronic

kidney diseases These diseases cause

more than 85 percent of all deaths, and

this figure is destined to rise as the U.S

population becomes increasingly older,

particularly during the first quarter of this

century when the baby boomers of the

1940s and 1950s reach their senior years

The two primary factors that

influ-ence one’s health status are genetics and

lifestyle According to Simopoulos, all

diseases have a genetic predisposition

The Human Genome Project, which

deciphered the DNA code of our 80,000

to 100,000 genes, has identified various

genes associated with many chronic diseases, such as breast and prostate cancer Genetically, females whose mothers had breast cancer are at increased risk for breast cancer, while males whose fathers had prostate cancer are

at increased risk for prostate cancer

Completion of the Human Genome Project is believed to be one of the most significant medical advances of all time

Although multiple genes are involved

in the etiology of most chronic diseases and research regarding the application

of the findings of the Human Genome Project to improve health is still in its initial stages, the future looks bright

For individuals with genetic profiles predisposing them to a specific chronic disease, such as cancer, genetic therapy eventually may provide an effective treatment or cure

Although genetic influences may play

an important role predisposing an vidual to a chronic disease, so, too, does lifestyle The CDC notes that although chronic diseases are among the most common and costly health problems, they are also among the most prevent-able by adopting a healthy lifestyle Over the years, scientists in the field of epi-demiology have identified a number of lifestyle factors considered to be health risks; these lifestyle factors are known as

indi-risk factors A indi-risk factor is a lifestyle

behavior that has been associated with

a particular disease, such as cigarette smoking being linked to lung cancer

A major risk factor is being overweight or obese, a condi-tion which affects almost two-thirds of Americans and

is increasing worldwide

The Department of Health and Human Services recently listed the leading lifestyle-related causes

of premature death in the United States

The combination of an unhealthy diet and physical inactivity, which may contribute

to being overweight or obese, was ranked

as the leading cause, followed by tobacco use and alcohol abuse

In a recent review, Hall noted that our genes harbor many secrets to a long and healthy life but also noted that genes alone are unlikely to explain all the secrets of longevity The role of a health-ful diet and exercise are intertwined with your genetic profile What you eat and how you exercise may influence your

genes Epigenetics is a relatively new

field of research involving the role of

the epigenome, a structure located just

outside the genome that may activate or deactivate DNA and subsequent genetic and cellular activity Cloud noted that various factors in our environment, such as substances in the foods we eat, may interact with the epigenome and thus modify cell functions—either in a positive or negative manner Exercise, as noted later, also stimulates release of sub-stances from muscle cells that may affect the epigenome Cloud notes that compa-rable to the Human Genome Project, a Human Epigenome Project is under way,

and epigenetics may eventually lead to

many beneficial health-related

applica-tions For example, if personal genetic

code indicates that your genetic profile

predisposes you to certain forms of

can-cer, and if your genetic profile indicates

that you will respond favorably to

spe-cific nutritional or exercise interventions,

then a preventive diet and an exercise

plan may be individualized for you

Genomics represents the study of genetic

material in body cells, and the terms

nutrigenomics and exercisenomics have

been coined to identify the study of the

genetic aspects of nutrition and exercise,

respectively, as related to health benefits

Sportomics involves study of the

meta-bolic response of the athlete in an actual

sport environment, not in a laboratory

Treatment of chronic diseases is

very expensive Foreseeing a financial

health-care crisis associated with an

increasing prevalence of such diseases

during the first half of this century, most

private and public health professionals

have advocated health promotion and

disease prevention as the best approach

to address this potential major health

problem Martinez-Perez and others

note that with more than 1 billion smart

phones around the world, the use of

various applications for health

promo-tion has great potential The HHS,

beginning in the 1980s, has published

a series of reports designed to increase

the nation’s health; the latest version is

entitled Healthy People 2020: National

Health Promotion/Disease Prevention

Objectives. Physical activity/fitness and

overweight/obesity are two of the major

focus areas These reports emphasize

that lifestyle behaviors that promote

health and reduce the risk of chronic

diseases are basically under the control

of the individual The role of diet and

exercise in health promotion has become

a worldwide priority, as documented

in the WHO report Global Strategy on

Diet, Physical Activity and Health. The guidelines presented in these reports underlie the recommendations presented

in this book For both reports, see web addresses below

As we shall see, proper exercise and proper nutrition, both individually and combined, may reduce many of the risk factors associated with the development

of chronic diseases These healthful benefits will be addressed at appropriate points throughout the book

Nutrition, fitness, and sport. Sport is

now most commonly defined as a petitive athletic activity requiring skill or physical prowess, for example, baseball, basketball, soccer, football, track, wres-tling, tennis, and golf As with health status, athletic ability and subsequent success in sport are based primarily upon genetics and epigenetics In a review of epigenetics in sport, Ehlert and others note that natural genetic endowment with characteristics important to a spe-cific sport must be maximized through epigenetic modifications by appropriate type and amount of training

com-To be successful at high levels of competition, athletes must possess the appropriate biomechanical, physi-ological, and psychological genetic characteristics associated with success in a given sport

International-class letes have such genetic traits In recent reviews, Tucker and others high-lighted the genetic basis for elite running performance while Eynon and others discussed the role of genes for elite power and sprint performance

ath-Moreover, Wolfarth and others have

assembled a human gene map for formance and health-related fitness

per-To be successful at high levels of competition, athletes must also develop their genetic characteristics maximally through proper biomechanical, physi-ological, and psychological coaching and training Whatever the future holds for genetic enhancement of athletic perfor-mance, specialized exercise training will still be the key to maximizing genetic potential for a given sport activity

Training programs at the elite level have become more intense and individualized, sometimes based on genetic predisposi-tions Modern scientific training results in significant performance gains, and world records continue to improve David

Epstein, in his book The Sports Gene,

provides a fascinating account of the role both genes and the training environment play relative to elite sport performance

Proper nutrition also is an important component in the total training program

of the athlete Certain nutrient cies can seriously impair performance, whereas supplementation of other nutri-ents may help delay fatigue and improve performance Over the past 50 years, research has provided us with many answers about the role of nutrition in athletic performance, but unfortunately some findings have been misinterpreted

deficien-or exaggerated so that a number of conceptions still exist

mis-The purpose of this chapter is

to provide a broad overview of the role that exercise and nutri-tion may play relative to health, fitness, and sport, and how prudent recommendations may be determined

More detailed information regarding specific relationships of nutritional prac-tices to health and sports performance is provided in subsequent chapters

www.health.gov/healthypeople Check for the full report of

Healthy People 2020.

www.who.int/dietphysicalactivity/en/ Check for the World

Health Organization report on diet and physical activity for health

www.ncbi.nlm.nih.gov/genome/guide/human/ For the

inter-ested reader, this site accesses the human genome map and

the National Institutes of Health Epigenetics Roadmap

Several health professional organizations, such as the American College of Sports Medicine (ACSM) and American Heart Association (AHA), have indicated that various forms of physi-

cal activity may be used to enhance health In general, physical activity involves any bodily movement caused by muscular con-

traction that results in the expenditure of energy For purposes of studying its effects on health, some epidemiologists classify phys-ical activity as either unstructured or structured

Unstructured physical activity, also known as leisure-time

activity, includes many of the usual activities of daily living, such

as leisurely walking and cycling, climbing stairs, dancing, ing and yard work, various domestic and occupational activities, and games and other childhood pursuits These unstructured activ-ities are not normally planned to be exercise However, as will

garden-be noted in chapter 11, these so-called nonexercise activities may play an important role in body weight control

Structured physical activity, as the name implies, is a planned

program of physical activities usually designed to improve cal fitness, including health-related fitness For the purpose of this

physi-book, we shall refer to structured physical activity as exercise,

particularly some form of planned moderate or vigorous exercise, such as brisk, not leisurely, walking

What are the basic principles of exercise training?

Exercise training programs may be designed to provide cific types of health-related fitness benefits and/or enhance specific types of sports-related fitness However, no matter what the purpose, several general principles are used in developing an appropriate exercise training program

spe-Principle of Overload Overload is the basic principle of exercise training, and it represents the intensity, duration, and frequency of exercise For example, a running program for cardiovascular-respiratory fitness could involve training at an intensity of 70 percent of maximal heart rate, a duration of

30 minutes, and a frequency of 5 times per week The adaptations the body makes are based primarily on the specific exercise over-

load The terms moderate exercise and vigorous exercise are often

used to quantify exercise intensity and are discussed later in this chapter and in more detail in chapter 11

Principle of Progression Progression is an extension of the overload principle As your body adapts to the original overload, the overload must be increased if further beneficial adaptations are desired For example, you may start lifting a weight of 20 pounds, increase the weight to 25 pounds as you get stronger, and so forth The overloads are progressively increased until the final health-related or sports-related goal is achieved or exercise limits are reached

Principle of Specificity Specificity of training represents the cific adaptations the body will make in response to the type of exer-cise and overload For example, running and weight lifting impose different demands on muscle energy systems, so the body adapts accordingly Both types of exercise may provide substantial, yet dif-ferent, health benefits Exercise training programs may be designed specifically for certain health or sports-performance benefits

spe-Health-Related Fitness:

Exercise and Nutrition

Physical fitness may be defined, in general terms, as a set of

abili-ties individuals possess to perform specific types of physical activity

The development of physical fitness is an important concern of many

professional health organizations, including the Society of Health

and Physical Educators (SHAPE), which has classified fitness

com-ponents into two different categories In general, these two categories

may be referred to as health-related fitness and sports-related fitness

Both types of fitness may be influenced by nutrition and exercise

Exercise and Health-Related Fitness

What is health-related fitness?

As mentioned previously, one’s health status or wellness is

influ-enced strongly by hereditarian predisposition and lifestyle

behav-iors, particularly appropriate physical activity and a high-quality

diet As we shall see in various sections of this book, one of the

key factors in preventing the development of chronic disease is

maintaining a healthful body weight

Proper physical activity may certainly improve one’s health

status by helping to prevent excessive weight gain, but it may

also enhance other facets of health-related fitness as well

Health-related fitness includes not only a healthy body weight and

com-position but also cardiovascular-respiratory fitness, adequate

muscular strength and muscular endurance, and sufficient

flex-ibility (figure 1.1) As one ages, other measures used as markers

of health-related fitness include blood pressure, bone strength,

postural control and balance, and various indicators of lipid and

carbohydrate metabolism

C h e c k f o r Yo u r s e l f

c Discuss with your parents any health problems they or your

grandparents may have, such as high blood pressure or

diabetes, to determine whether you may be predisposed to

such health problems in the future Having such knowledge

may help you develop a preventive exercise and nutrition

plan early in life Please use the following website to create

your own family history

www.hhs.gov/familyhistory Create your own family health

history

c Several of the key health promotion objectives set by the

U.S Department of Health and Human Services in Healthy

People 2020 are increased levels of physical activity, a

healthier diet, and reduced levels of overweight and obesity

c Sports success is dependent on biomechanical,

physiologi-cal, and psychological genetic characteristics specific to a

given sport, but proper training, including proper nutrition, is

essential to maximize one’s genetic potential

use of exercise, the body will begin to lose the adaptations it has made over the course of the exercise program Individuals who suffer a lapse in their exercise program, such as a week or so, may lose only a small amount of health-related fitness gains However,

a total relapse to a previous sedentary lifestyle can reverse all health-related fitness gains

Principle of Overuse Overuse represents an excessive amount

of exercise that may induce some adverse, rather than beneficial, health effects Overuse may be a problem during the beginning stages of an exercise program if one becomes overenthusiastic and exceeds her capacity, such as developing shin splints by running too far Overuse may also occur in elite athletes who become over-trained, as discussed in chapter 3

Specific exercise programs for healthy body weight and position, cardiovascular-respiratory fitness, and muscular strength and muscular endurance are detailed in chapters 11 and 12, and several of these principles are discussed in more detail

com-Principle of Recuperation Recuperation is an important

princi-ple of exercise training Also known as the principrinci-ple of recovery, it

represents the time in which the body rests after exercise This

prin-ciple may apply within a specific exercise period, such as including

rest periods when doing multiple sets during a weight-lifting

work-out It may also apply to rest periods between bouts of exercise, such

as a day of recovery between two long cardiovascular workouts

Principle of Individuality Individuality reflects the effect

exercise training will have on each individual, as determined by

genetic characteristics The health benefits one receives from

a specific exercise training program may vary tremendously

among individuals For example, although most individuals

with high blood pressure may experience a reduction during a

cardiovascular-respiratory fitness training program, some may not

Principle of Reversibility Reversibility is also referred to as the

principle of disuse, or the concept of use it or lose it Without the

F I G U R E 1 1

Health-related fitness components

The most important physical

fitness components related

to personal health include

cardiovascular-respiratory

fitness, body composition,

muscular strength, muscular

endurance, and flexibility

Cardiovascular-respiratory fitness Body composition Muscular strength

∙ Promote healthy pregnancy of mother and fetus

∙ Improve quality of sleep

∙ Improve quality of life

∙ Increase longevityThese benefits may accrue to males and females of all races across all age spans You are never too young or too old to reap some of these health benefits of exercise

In essence, physically active individuals enjoy a higher quality

of life, a joie de vivre, because they are less likely to suffer the

dis-abling symptoms often associated with chronic diseases, such as loss of ambulation experienced by some stroke victims As noted

in the next section, physical activity may also increase the quantity

of life As quoted by Greider, James Fries, an emeritus sor who studies healthy aging at the Stanford University School

profes-of Medicine’s Center on Longevity, said, “If you had to pick one thing, one single thing that came closest to the fountain of youth, it would have to be exercise.”

How does exercise enhance health?

Recent news reports made headlines around the world, such as one

entitled Exercise Benefits: Rivals Drugs for Stroke, Heart Disease

Treatment. The question is, How?

What is the role of exercise

in health promotion?

The beneficial effect of exercise on health has

been known for centuries For example, Plato

noted that “lack of activity destroys the good

con-dition of every human being while movement and

methodical physical exercise save and preserve

it.” Plato’s observation is even more relevant in

contemporary society Frank Booth, a prominent

exercise scientist at the University of Missouri,

has coined the term Sedentary Death Syndrome,

or SeDS, and he and his colleagues recently

noted that physical inactivity is a primary cause

of most chronic diseases, the major killers in the

modern era Slentz and others discussed the cost

of physical inactivity over time The short-term

cost of physical inactivity is metabolic

deteriora-tion and weight gain; the intermediate-term cost

is an increase in disease, such as type 2 diabetes,

whereas the long-term cost is increased premature

mortality

To help promote the health benefits of

physical activity, the American College of Sports

Medicine and the American Medical Association

(AMA) launched a program, entitled Exercise Is

Medicine TM, designed to encourage physicians

and other health-care professionals to include

exercise as part of the treatment for every patient

Clinical, epidemiological, and basic research

evi-dence clearly supports the inclusion of regular

physical activity as a tool for the prevention of

chronic disease and the enhancement of overall

health Booth and others note that physical activity/exercise has

been studied as a primary prevention against 35 chronic health

problems, and numerous studies and reviews have documented the

manifold health benefits, which are highlighted in the following

list and in figure 1.2

∙ Control body weight

∙ Reduce risk of metabolic syndrome

∙ Reduce risk of high blood pressure

∙ Reduce risk of type 2 diabetes

∙ Enhance blood lipid profile

∙ Reduce risk of heart disease

∙ Promote recovery from heart disease

∙ Reduce risk of stroke

∙ Reduce risk of breast cancer

∙ Reduce risk of colon cancer

∙ Improve self-image

∙ Reduce risk of mental depression

∙ Enhance cognitive functions in the elderly

∙ Reduce risk of falls in the elderly

∙ Delay onset and severity of Alzheimer’s disease

∙ Strengthen bones and muscles

∙ Reduce arthritis pain

∙ Improve immune functions

F I G U R E 1 2 Exercise is medicine Here are some of the benefits of regular moderate physical activity and exercise See text for discussion

Improves sleep (if activity is done in the morning or afternoon)

Reduces risk of colon cancer, prostate cancer, and likely breast cancer

Increases bone density and strength blood pressureReduces

Increases cardiovascular function and improves blood lipid profile; helps prevent heart disease and stroke

Reverses brain deterioration with aging; helps prevent,

or delay, Alzheimer’s disease;

improves executive functioning

Aids in weight loss/weight control

Increases muscle mass, muscular strength, and muscular endurance

Promotes a healthy pregnancy

Increases strength, flexibility, and balance;

reduces risk of falling

Improves immune function

Reduces stress and improves self-image;

helps prevent mental depression

Increases insulin sensitivity; improves blood glucose regulation; helps prevent type 2 diabetes

that one of the common causes of various chronic diseases is an inflammatory environment created by the presence of excess fat, particularly within blood vessels Local inflammation is thought

to promote the development of heart disease, cancer, diabetes, and dementia According to Nimmo and others, exercise produces an anti-inflammatory cytokine that may help cool inflammation and reduce such health risks They note that the most marked improve-ments in the inflammatory profile are conferred with exercise per-formed at higher intensities, with combined aerobic and resistance exercise training potentially providing the greatest benefit

Cytokines and heat shock proteins may prevent chronic eases in other ways as well, such as increasing the number of glu-cose receptors in muscle cells, improving insulin sensitivity, and helping to regulate blood glucose and prevent type 2 diabetes.There are also other health-promoting mechanisms of exercise One of the most significant contributors to health problems with aging is sarcopenia, or loss of muscle tissue In their review, Landi and others conclude that regular exercise is the only strategy found

dis-to consistently prevent frailty and improve sarcopenia and physical function in older adults The following are some other examples:

∙ Loss of excess body fat may reduce production of cytokines that may impair health

∙ Loss of excess body fat may reduce estrogen levels, reducing risk of breast cancer

∙ Reduction of abdominal obesity may decrease blood pressure and serum lipid levels

∙ Increased mechanical stress on bone with high-impact exercise may stimulate increases in bone density

∙ Production of some cytokines, such as BDNF, may enhance neurogenesis and brain functions

The specific mechanisms whereby exercise may help to prevent

the development of various chronic diseases are not completely

understood but are involved with changes in gene expression that

modify cell structure and function Physical inactivity is a major

risk factor for chronic diseases As noted previously, Booth and

Neufer indicated physical inactivity causes genes to misexpress

proteins, producing the metabolic dysfunctions that result in overt

clinical disease if continued long enough In contrast, exercise

may cause the expression of genes with favorable health effects

Most body cells can produce and secrete small proteins known

as cytokines, which are similar to hormones and can affect

tis-sues throughout the body Cytokines enter various body tistis-sues,

influencing gene expression that may induce adaptations either

favorable or unfavorable to health (figure 1.3) Two types of

cyto-kines are of interest to us Muscle cells produce various cytocyto-kines

called myokines (referred to as exerkines when produced during

exercise), whereas fat (adipose) cells produce cytokines called

adipokines Muscle cells also produce heat shock proteins (HSPs),

which may have beneficial health effects The following represent

several important cytokines produced in muscle and fat cells:

Interleukin-6 (IL-6) Tumor Necrosis Factor-alpha (TNF-a)

Brain-Derived Neurotropic

Factor (BDNF)

Adiponectin

F I G U R E 1 3 Exercise may induce adaptations that have favorable health effects in various body tissues One suggested mechanism

is the effect that various hormones or cytokines, which are produced during exercise, may have on gene regulation in body cells

(1 ) The hormone or cytokine binds to a cell receptor that activates a signal within the cell, (2 ) the signal is transmitted along a specific pathway, (3) the signal may alter gene expression and induce changes within the cell Cell signals may also affect enzymes or other cell

structures that may induce beneficial health effects

Unactivated receptor protein Signal transmission pathway

Hormone

or

Cytokine

Receptor activation

1

2

Cellular response 3

Overall, Brandt and Pederson theorize that exercise-induced

cytokine effects on genes reduce many of the traditional risk

fac-tors associated with development of chronic diseases; Geiger and

others note similar effects for HSPs In particular, McAtee notes

following recommendations for adults have been formatted into

a MyActivity Pyramid, a graphic depicting exercise guidelines

The latest version, developed by Stephen Ball at the University of Missouri, is presented in figure 1.5

Numerous reports providing exercise recommendations for health benefits have been released by various professional and govern-

mental health-related organizations, including the Physical Activity

Guidelines for Americans from the U.S Department of Health and

Human Services and the National Physical Activity Plan, a coalition

report from the American Heart Association, the American College

of Sports Medicine, the Centers for Disease Control and Prevention, and many other such organizations Here are some of the key points

to help you reap the many health benefits of physical activity

∙ Individualization Exercise programs should be

individual-ized based on physical fitness level and health status Claude Bouchard, an expert in genetics, exercise, and health, noted that due to genes, physical activity may benefit some, but not others

For example, although most sedentary individuals will respond favorably to an aerobic exercise training program, such as an improved insulin sensitivity, others will not respond and have

no change in insulin sensitivity Currently, there is no gene file for responders and nonresponders to exercise training, but that may change in the future so that specific exercise programs may be designed for individuals

pro-∙ Leisure-time activity A key component of a fitness plan is

simply to reduce the amount of daily sedentary activity One important modification to your daily lifestyle is to sit less and

Some healthful adaptations may occur with a single bout of

exercise Nimmo and others reported that single bouts of exercise

have a potent anti-inflammatory influence, while others have noted

that a single exercise session can acutely improve the blood lipid

profile, reduce blood pressure, and improve insulin sensitivity,

all beneficial responses However, such adaptations will regress

unless exercise becomes habitual Thus, to maximize health

ben-efits, exercise should be done most days of the week because many

of its benefits stem from the most recent exercise sessions The role

that exercise may play in the prevention of some chronic diseases,

such as heart disease and diabetes, and associated risk factors, such

as obesity, are discussed throughout this book where relevant

Do most of us exercise enough?

In general, NO Surveys reveal that most adult Americans and

Canadians have little or no physical activity in their daily lives For

example, the Healthy People 2020 report from the United States

Department of Health and Human Services indicates that more

than 80 percent of adults do not meet the guidelines for both

aero-bic and muscle-strengthening activities Similarly, a recent study

by Song and others indicated more than 80 percent of adolescents

do not do enough aerobic physical activity to meet the guidelines

for youth Harvey and others reported the majority of older adults

are sedentary, many sitting for prolonged periods Thus, one of the

major goals of Healthy People 2020 is to decrease the amount of

physical inactivity, such as television viewing, and increase the

amount of physical activity in both adults and youth

How much physical activity

is enough for health benefits?

In general, there is a curvilinear relationship between the amount

of physical activity (dose) and related health benefits (response), as

depicted by the dose-response graph in figure 1.4 A sedentary

life-style has no health benefits, but health benefits increase rapidly with

low to moderate levels of weekly activity Beyond moderate levels

of weekly physical activity, the increase in health benefits will

con-tinue to increase gradually and then plateau Excessive exercise may

actually begin to have adverse effects on some health conditions

However, as noted by Bouchard, there may be other specific

dose–response curves Some health conditions may improve

rapidly with low to moderate weekly levels of physical activity,

whereas others may necessitate increased levels As an example

of the latter, the ACSM Position Stand on physical activity and

weight loss has noted that while moderate-intensity exercise

between 150 and 250 minutes weekly will provide only modest

weight loss, greater amounts of physical activity, averaging more

than 250 minutes weekly, have been associated with clinically

significant weight loss Dependent on the desired health outcome,

the dose (intensity, duration, frequency) of physical activity may

vary accordingly, as will type of physical activity To reap the

health benefits of exercise, most health professionals recommend

a comprehensive program of physical activity, including aerobic

exercise and resistance training Flexibility and balance exercises

become increasingly important for older adults In general, the

F I G U R E 1 4 Significant health benefits may occur at low

to moderate levels of physical activity with diminishing returns

at higher levels Excessive amounts or intensity of exercise, depending on the individual, may predispose to various types of health problems See text for discussion

0

of 150  minutes every week, or about 30 minutes for 5 days Alternatively, both may engage in vigorous-intensity exercise, such as jogging or running, for 75 minutes every week Gibala and

others noted the term high-intensity interval training (HIIT)

should be used to describe protocols in which the training lus is “near maximal” or the target intensity is between 80 and

stimu-100 percent of maximal heart rate They also suggest sprint

inter-val training (SIT) be used for protocols that involve mal efforts, in which target intensities correspond to workloads greater than what is required to elicit 100 percent of maximal oxygen uptake (VO2 max) These supramaximal exercise tasks may be accomplished in much less time as compared to moderate-intensity exercise, and Kilpatrick and others indicate 75 minutes weekly of such exercise could provide significant health benefits Additionally, adults may engage in an equivalent mix of moder-ate- and vigorous-intensity exercise over the course of the week.Children and adolescents should do 60 minutes of moder-ate to vigorous physical activity daily Short bursts of vigorous activity in games are included Exergames, interactive video games that promote physical activity, may hold promise to pro-mote aerobic physical activity in youth

supramaxi-move more Here are some examples to help build light

physi-cal activity into your daily schedule:

∙ If you sit all day at work, take a short break every hour and

walk around for several minutes

∙ Take a walk after lunch and dinner

∙ Walk to the store instead of driving

∙ Stand instead of sit when you can

∙ Get up and move during commercial breaks when watching

television

∙ Take the stairs instead of the elevator

∙ Walk your dog instead of letting him out into the backyard

(your dog needs exercise too)

Accumulating more daily unstructured physical activity may be

very helpful in maintaining a healthy body weight Additionally,

leisurely walking may be adequate physical activity for elderly

individuals with compromised health status or very low fitness

levels

∙ Aerobic exercise For important health benefits, both adults

and older adults should engage in moderate-intensity aerobic

(endurance) exercise, such as brisk walking, for a minimum

F I G U R E 1 5 One version of a physical activity pyramid See text for more specific information regarding exercise intensity and duration for adults and older adults

Courtesy of Dr Stephen D Ball Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO.

should perform about 8 to 12 repetitions of each exercise at least twice a week on nonconsecutive days Older adults may lift lighter weights or use less resistance, but do more repeti-tions Resistance exercises may include use of weights or other resistance modes or weight-bearing activities such as stair climbing, push-ups, pull-ups, and various other calisthenics that stress major muscle groups Resistance exercise programs will be discussed in chapter 12.

∙ Flexibility and balance exercise Older adults should perform

activities that help maintain or increase flexibility on at least

2 days each week for at least 10 minutes Flexibility exercises are designed to maintain the range of joint motion for daily activities and physical activity Older adults should also per-form exercises that help maintain or improve balance about

3 times a week Such exercises may help reduce the risk of injury from falls Appropriate exercises are presented in the National Institute of Aging program, Go4Life, included in the following Websites

∙ More is better The Physical Activity Guidelines for Americans

notes that more exercise time, particularly increasing the weekly amount of moderate-intensity aerobic activity to 300 minutes or vigorous-intensity aerobic activity to 150 minutes, or an equiv-alent combination of the two, equals more health benefits The

Guidelines also note that going beyond this 300 or 150 minutes

a week will provide even more health benefits Some support

for this viewpoint was provided in a recent Consumer Reports

on Health article In a summary of an analysis of studies ing 655,000 adults, 75 minutes a week of moderate physical activity, such as brisk walking, was linked to an additional 1.8 years of life expectancy, whereas people who were active at least 450 minutes (7.5 hours) a week added 4.5 years

involv-For those who have the time and energy, exceeding the ommended amounts of physical activity may provide additional health benefits In particular, as noted previously, more exer-cise may be an important consideration to promote weight loss and prevent weight gain, a major factor in promoting health

rec-If you are interested in starting an exercise program, you may preview chapter 3 for a discussion of energy expenditure during exercise The Compendium of Physical Activities and the con-cept of the MET as a measure of exercise intensity is introduced

You may also preview chapter 11 to design an aerobics exercise program for cardiovascular-respiratory fitness and proper weight control, and chapter 12 to design a resistance training program for muscular strength and endurance Additionally, the following excellent Websites provide detailed guidelines for physical activ-ity as indicated

Health benefits may be achieved whether the daily minute

allot-ment for exercise is done continuously, or as three10-minute

exer-cise snacks done throughout the day, such as three brisk walks

Aerobic exercise programs, including the determination of

moderate- and vigorous-intensity exercise and discussion of

HIIT, are detailed in chapters 3 and 11 In brief, exercise

inten-sity is based on the MET, a term associated with the metabolic

rate that will be explained in detail in chapter 3 Your resting

metabolic rate, such as when you are sitting quietly, is 1 MET

Moderate-intensity exercise is about 3–6 METs, and

vigorous-intensity exercise is greater than 6 METs You may access the

MET values for a wide variety of physical activities at the

Moderate-Intensity Exercise Vigorous-Intensity Exercise

Leisurely bicycling, 5–8 mph Bicycling, 12 mph and faster

Walking, leisurely, 2 mph Walking, 4.5 mph and faster

Dancing, slow ballroom Dancing, aerobic, with 6- to

8-inch step Jogging, slow on a mini-tramp Jogging/running, 4 mph and faster

Swimming, slow leisurely Swimming, fast crawl, 50 yards/

minute

Golf, walking, carrying clubs Basketball, competitive game

Pilates, general Exergaming, vigorous effort

TABLE 1.1 Some examples of moderate-intensity

and vigorous-intensity exercise

https://sites.google.com/site/compendiumofphysicalactivities/

Click on Activity Categories, such as bicycling, and the METs

value will be provided for a wide variety of bicycling activities

∙ Some examples of moderate- and vigorous-intensity exercise

are presented in Table 1.1

For the present, the following characteristics of the talk test

while exercising may be may sufficient to determine exercise

intensity

Light: You can carry on a normal conversation.

Moderate: You can talk, but not sing but a few notes before

taking a breath

Vigorous: You cannot say more than a few words.

∙ Resistance exercise Resistance exercise also conveys

signifi-cant health benefits

Both adults and older adults should engage in muscle-

strengthening activities on 2 or more days a week that work all

major muscle groups (legs, hips, back, abdomen, chest,

shoul-ders, and arms) Children and adolescents should do the same

at least 3 days a week The recommendation includes about 8 to

10 exercises that stress these major muscle groups Individuals

seeking health benefits of exercise Given our current state of knowledge, adhering to the guidelines presented above, preferably

at the upper time and day limits, should be safe and provide mal health benefits associated with physical activity However, exercise, particularly when excessive and in individuals with preexisting health problems, may increase health risks Training for and participating in various sports may also predispose one to various health problems

opti-∙ Orthopedic problems Too much exercise may lead to

orthope-dic problems, such as stress fractures in the lower leg in those who run, particularly in those with poor biomechanics Injuries

to tendons and bones are common in some sports However, recovery from such orthopedic problems occurs with proper rest

∙ Impaired immune functions Couto and others noted that while

moderate physical activity may enhance immune function, longed, high-intensity exercise temporarily impairs immune competence, which may be associated with an increased inci-dence of upper respiratory tract infections Moreover, accord-ing to a recent review by Nijs and others, individuals with chronic fatigue syndrome, discussed in chapter 3, may have an altered immune response to exercise and other reports link it to excessive exercise

pro-∙ Exercise-induced asthma Couto and others indicate some

endurance athletes, such as runners and cross-country skiers, particularly when exercising in cold weather, may be more prone to exercise-induced asthma Excessive lung ventilation may dry the airways with subsequent release of inflammatory mediators that cause contraction of the airways, making breath-ing more difficult In severe cases, exercise-induced asthma may be fatal

∙ Exercise addiction Exercise is known to release various brain

chemicals, including endorphins, which may elicit euphoric

feelings such as the runners high However, Weinstein and

Weinstein note that exercise addiction may also have an obsessive-compulsive dimension and may be linked to other psy-chiatric disorders, such as substance abuse and eating disorders

∙ Osteoporosis When coupled with inadequate dietary energy

intake, exercise that leads to excessive weight loss may ute to the menstrual irregularities in female athletes that may exacerbate loss of bone mass, or osteoporosis Known as the female athlete triad, this topic is discussed in chapters 8 and 10

contrib-∙ Heat illness and kidney failure Exercising in the heat may cause

heat stroke or other heat illnesses with serious consequences, such as kidney failure and death, as discussed in chapter 9

∙ Brain damage As noted previously, exercise exerts multiple

beneficial effects on the brain, such as improved psychological health and reduced risk of mental decline with aging McKee and others document the multiple benefits but also note that participation in some sports may be associated with mild trau-matic brain injury (mTBI) and, rarely, catastrophic traumatic injury and death Repetitive mTBIs, such as concussions, can lead to neurodegeneration, or chronic traumatic encephalopa-thy (CTE) CTE has been reported most frequently in American football players and boxers but is also associated with other sports such as ice hockey, soccer, rugby, and baseball

Am I exercising enough?

Several approaches may be used to answer this question One

approach is to keep a record of all your physical activity for a

week, such as how many minutes you walk; engage in some type

of aerobic physical activity such as swimming, cycling, or jogging;

or perform resistance exercise such as lifting weights Chapter 11

contains a form you can use, modifying it as you see fit, to record

your daily physical activities Tallying your totals for the week

and comparing them to the previously mentioned

recommenda-tions for aerobic and resistance exercise will give you a good idea

as to whether you are meeting current recommendations Another

method, which provides a more detailed analysis, is to use the

program at www.ChooseMyPlate.gov Click on Interactive Tools,

then Food Tracker to assess your physical activity

The most recent method involves the use of exercise gadgets

that can monitor and record your daily levels of physical activity

Such gadgets started with the basic pedometer, but according to

a recent Consumer Reports review, currently there are numerous

gadgets you can wear on your wrist or put in your pocket that will

effortlessly synchronize with your smartphone and provide you

data on heart rate, blood pressure, energy (Calories) expended,

and other health-related variables

Consumer Reports suggests the Fitbit One may be worth your

money It counts steps, calculates Calories expended, and tells you

how close you are to meeting your daily health goals Other Fitbit

models log foods you eat and track caloric intake Highly

recom-mended for iPhone users is Moves, a free app that records your

running, cycling, swimming, exercise time in the gym, and much

more, including periods of physical inactivity

Numerous other fitness apps are available About the time this

book went to press, Hongu and others indicated more than 13,600

mobile phone health apps were currently available on the market

You can Google the terms Fitness Apps and Free Fitness Apps

and peruse those available These fitness apps not only record

your physical activity; many also are designed to help promote

regular physical activity and related health behaviors

Can too much exercise be harmful to my health?

In general, the health benefits far outweigh the risks of exercise

Although individuals training for sport may need to undergo

pro-longed, intense exercise training, such is not the case for those

www.cdc.gov/physicalactivity/everyone/guidelines/adults.html

Provides details on complete exercise programs for adults

www.who.int/dietphysicalactivity/pa/en/ The World Health

Organization provides recommendations on diet and physical

activity to promote health

www.fitness.gov/be-active/ The President’s Council on

Fitness, Sports, & Nutrition provides ideas to help you

become more physically active

http://www.cdc.gov/physicalactivity/basics/measuring/

This video provides information on exercise intensity

Nutrition and Health-Related Fitness

What is nutrition?

Nutrition usually is defined as the science of food, involving the

sum total of the processes involved in the intake and utilization of food substances by living organisms, including ingestion, diges-tion, absorption, transport, and metabolism of nutrients found in food This definition stresses the biochemical or physiological functions of the food we eat, particularly in relation to health and disease Additionally, the Academy of Nutrition and Dietetics notes that nutrition may be interpreted in a broader sense and be affected

by a variety of psychological, sociological, and economic factors

From a standpoint of health and sport performance, it is the chemical and physiological role or function of food that is impor-tant However, economic factors, particularly with some college students, may influence healthful food selection For example, healthier foods such as fresh fruits and vegetables, even though they require minimal processing, are more expensive than highly processed food laden with highly refined grains, sugar, and fat, three inexpensive ingredients Calculations derived from a recent visit to a local discount food supermarket indicated that this is what $1 will buy:

bio-∙ 600 Calories of a top brand of potato chips

∙ 750 Calories of store-brand cola

∙ 40 Calories of fresh asparagus

∙ 50 Calories of fresh strawberriesThe primary purpose of the food we eat is to provide us with

a variety of nutrients A nutrient is a specific substance found in

food that performs one or more physiological or biochemical tions in the body There are six major classes of essential nutrients found in foods: carbohydrates, fats, proteins, vitamins, minerals, and water However, as noted in chapter 2, food contains substances other than essential nutrients that may affect body functions

func-∙ Heart attacks and sudden death Varró and Baczkó note that

although sudden death among young athletes is very rare, it is

still two to three times more frequent than in the age-matched

control population and attracts significant media attention

Sudden death in older athletic individuals may be associated

with coronary heart disease, discussed in detail in chapter 5

In brief, atherosclerosis in the heart’s blood vessels may limit

oxygen supply to the heart muscle, triggering what is known as

an ischemic heart attack In his review, Williams cautions heart

attack survivors to use caution with exercise, noting moderate

levels may be beneficial but higher levels may attenuate the

benefits He notes that for heart attack survivors, more exercise

is better, up to a point

∙ Accidents Given the nature of physical activity, particularly

competitive sports, accidental injuries occur, and some may

be fatal, such as a concussion causing serious head injury

Use safety gear as appropriate for your physical activity, such

as helmets for bicycling, rollerblading, and skiing, as well as

other protective sportswear as appropriate for any given

activ-ity Adhere to safety protocols for various activities, such as

cycling in traffic About 700 cyclists are killed annually in the

United States in collisions with automobiles In recent years,

reports indicate increasing emergency room visits by those who

walk and talk on their cell phones and experience an accident,

either by falls or being hit by motor vehicles

It is important to emphasize that although a properly planned

exercise program may be safe and confer multiple health benefits

to most individuals, exercise may be hazardous to some The most

common concern is a heart attack Individuals who have any

con-cerns about their overall health, particularly those over age 35,

should have a medical screening to detect risk factors for heart

disease, such as high blood pressure, before increasing their level

of physical activity Such a medical screening might include an

exercise stress test during which your heart rate and blood pressure

are monitored for abnormal responses Although exercise may be a

temporary risk, it conveys lasting protection The best protection for

the heart is to exercise frequently, mainly because regular exercise

helps prevent heart disease, as well as many other diseases, in the

first place Additional details are provided in subsequent chapters

Ke y C o n c e p t s

c Health-related fitness includes a healthy body weight,

cardiovascular-respiratory fitness, adequate muscular

strength and muscular endurance, and sufficient flexibility

c Overload is the key principle underlying the adaptations to

exercise that may provide a wide array of health benefits

The intensity, duration, and frequency of exercise represent

the means to impose an overload on body systems that

enable healthful adaptations

c Physical inactivity may be dangerous to your health Some

contend “Sitting is the new smoking.” Exercise, as a form

of physical activity, is becoming increasingly important as a

C h e c k f o r Yo u r s e l f

c As a prelude to activities presented in later chapters, make

a detailed record of all your physical activities for a full 24-hour day, from the moment you arise in the morning until you go to bed at night, and include sleep time

means to achieve health benefits, by preventing the ment of many chronic diseases

c Physical activity need not be strenuous to achieve health benefits, but additional benefits may be gained through more vigorous and greater amounts of physical activity

c In general, more exercise is better, up to a point Excessive exercise may cause some minor and major health problems

in some individuals You should be aware of personal health issues or other factors that may be related to exercise- associated health risks

in muscle and fat cells, may influence gene expression, some ing positive and others negative effects on our health For exam-ple, adequate amounts of certain vitamins and minerals may help prevent damage to DNA, the functional component of your genes, while excessive alcohol may lead to DNA damage.

hav-Most chronic diseases have a genetic basis; if one of your ents has had coronary heart disease or cancer, you have an increased probability of contracting that disease Such diseases may go through three stages: initiation, promotion, and progression Your genetic pre-disposition may lead to the initiation stage of the disease, but factors

par-in your environment that par-influence your epigenome may promote its development and eventual progression In this regard, some nutrients

are believed to be promoters that lead to progression of the disease, while other nutrients are believed to be antipromoters that deter the

initiation process from progressing to a serious health problem.What you eat plays an important role in the development or progression of a variety of chronic diseases For example, the Centers for Disease Control and Prevention indicates that good nutrition lowers people’s risk for many chronic diseases, including heart disease, stroke, some types of cancer, diabetes, and osteopo-rosis (see figure 1.7) The National Cancer Institute estimates that one-third of all cancers are linked in some way to diet, ranking just behind tobacco smoking as one of the major causes of cancer Schwingshackl and Hoffman recently noted that high adherence to

a healthy diet, such as the Mediterranean diet, is associated with

a significant reduction in the risk of overall cancer mortality, ticularly colorectal, prostate, and aerodigestive cancer

par-As noted previously, exercise is medicine In a like manner,

food is medicine may also be an appropriate phrase, not only utable to the quote from Hippocrates but also based on modern medicine as well The types and amount of carbohydrate, fat, and protein that we eat; the amount and type of other substances such

attrib-as vitamins, minerals, and phytochemicals found in our foods; the source of our food; and the method of food preparation are all fac-tors that may influence the epigenome and subsequent gene expres-sion or other metabolic functions that may affect our health status The following are some of the proposed effects of various nutrients and appropriate energy intake that may help promote good health:

∙ Inactivate carcinogens or kill bacteria that damage DNA

∙ Help repair DNA

∙ Increase insulin sensitivity

∙ Relax blood vessels and improve blood flow

∙ Reduce blood pressure

∙ Optimize serum lipid levels

∙ Reduce inflammation

∙ Inhibit blood clotting

∙ Enhance immune system functions

∙ Prevent damaging oxidative processes

∙ Dilute harmful chemicals in the intestines

∙ Promote more frequent bowel movements

∙ Curb appetite to help reduce body fatThe beneficial, or harmful, effects of specific nutrients and vari-ous dietary practices on mechanisms underlying the development

of chronic diseases will be discussed as appropriate in later tions of this book

sec-As illustrated in figure 1.6, the essential nutrients perform three

basic functions First, they provide energy for human metabolism

(see chapter 3) Carbohydrates and fats are the prime sources of

energy Protein may also provide energy, but this is not its major

function Vitamins, minerals, and water are not energy sources

Second, all nutrients are used to promote growth and development

by building and repairing body tissue Protein is the major building

material for muscles, other soft tissues, and enzymes, while certain

minerals such as calcium and phosphorus make up the skeletal

framework Third, all nutrients are used to help regulate and

main-tain the diverse physiological processes of human metabolism

In order for our bodies to function effectively, we need more

than 40 specific essential nutrients, and we need these nutrients in

various amounts as recommended by nutrition scientists Dietary

Reference Intakes (DRI) represent the current

recommenda-tions in the United States and include the Recommended Dietary

Allowances (RDA) These recommendations are detailed in

chap-ter 2 Nutrient deficiencies or excesses may cause various health

problems, some very serious

Although nutrients are important for our health, it is also

impor-tant to note that we do not eat nutrients; we eat food

What is the role of nutrition in health promotion?

As noted previously, your health is dependent upon the interaction

of your genes and your environment, and the food you eat is part

of your personal environment

This statement by Hippocrates, made over two thousand years

ago, is becoming increasingly meaningful as the preventative and

therapeutic health values of food relative to the development of

chronic diseases are being unraveled Nutrients and other

sub-stances in foods, similar to the aforementioned cytokines produced

Let food be your medicine and medicine be your food.

F I G U R E 1 6 Three major functions of essential nutrients

in food Many nutrients have only one key role (e.g., glucose

provides energy), whereas others have multiple roles (e.g.,

protein is necessary for growth and development and regulation

of metabolism, and it may be used as a source of energy)

Carbohydrates Fats

Proteins Vitamins Minerals Water

others throughout the world are consuming too many Calories, one

of the leading causes of the global obesity problem

To relate these nutrition findings to health in simplistic terms, most Americans eat more food (Calories) than they need, due in part to the increase in food portion sizes in recent years, and eat less of the food that they need more The major nutrition goal of

Healthy People 2020 is to get more Americans to change their faulty dietary habits Some advances are being made in the battle against unhealthy eating and obesity For example, some food manufacturers have reduced the amount of fat and salt in their products Some fast-food restaurants are offering healthier alterna-tives, such as oatmeal with fruit for breakfast The National School Lunch Program has promoted a program to incorporate more fresh fruit and vegetables into daily school lunches Although these are worthwhile endeavors, many more are needed before we can state that “We are eating right.”

Do we eat right?

Surveys indicate that most people are aware of the role of nutrition

in health and want to eat better for healthful purposes, but they do

not translate their desires into appropriate action Poor eating habits

span all age groups According to the recent Dietary Guidelines for

Americans report, on average Americans of all ages consume too

few vegetables, fruits, high-fiber whole grains, low-fat milk

prod-ucts, and seafood and they eat too much added sugars, solid fats,

refined grains, and sodium The Dietary Guidelines recommend

that solid fats and sugars (SoFAS) should constitute only 15 percent

of Calories in the American diet, but they account for 35 percent

of daily caloric intake for most Americans In a study of more than

16,000 Americans, Krebs-Smith and others concluded that nearly

the entire U.S population consumes a diet that is not on par with

recommendations In particular, many Americans, Canadians, and

F I G U R E 1 7 Some possible health problems associated with poor dietary habits An upward arrow ( ) indicates excessive intake,

while a downward arrow ( ) indicates low intake or deficiency

Prostate cancer

Saturated fat ( ↑

Tomatoes ( ↓ ) Tomato-based foods ( ↓ )

Stomach cancer

Cured smoked foods ( ↑

Osteoporosis

Calcium ( ↓ ) Vitamin D ( ↓ )

Breast cancer

Alcohol ( ↑

Obesity ( ↑ Cataracts Fruits and vegetables ( ↓

these recommendations as a Prudent Healthy Diet These

recom-mendations are in accordance with the total diet approach of the

Academy of Nutrition and Dietetics and the various governmental and professional health organizations noted above Each specific dietary recommendation may convey some health benefit, so the more of these dietary guidelines you adopt, the greater should be your overall health benefits

1 Balance the food you eat with physical activity to maintain

or improve your body weight Consume only moderate food portions Be physically active every day

2 Eat a nutritionally adequate diet consisting of a wide variety

of nutrient-rich foods Eat more whole foods in their natural form Eat fewer highly processed foods

3 Eat a diet rich in plant foods Choose plenty of fruits and etables, whole-grain products, and legumes, which are rich in healthy carbohydrates, phytochemicals, and fiber

4 Choose a diet moderate in total fat but low in saturated and

trans fat and cholesterol

5 Choose beverages and foods that moderate or reduce your intake of sugars, particularly added sugars

6 Choose and prepare foods with less salt and sodium

7 Maintain protein intake at a moderate yet adequate level, obtaining much of your daily protein from plant sources, complemented with smaller amounts of fish, skinless poultry, and lean meat

8 Choose a diet adequate in calcium and iron

9 Practice food safety, including proper food storage, tion, and preparation

10 Consider the possible benefits and risks of food additives and dietary supplements

11 If you drink alcoholic beverages, do so in moderation nant women should not drink any alcohol

12 Enjoy your food Eat what you like, but balance it within your overall healthful diet

An expanded discussion of these guidelines along with cal recommendations to help you implement them is presented in chapter 2 Additional details on how each specific recommendation may affect your health status, including specific considerations for women, children, and the elderly, are presented in appropri-ate chapters throughout this book The following Websites present detailed information on healthy dietary guidelines:

practi-What are some general guidelines for healthy eating?

Because the prevention of chronic diseases is of critical

impor-tance, thousands of studies have been and are being conducted to

discover the intricacies of how various nutrients may affect our

health Particular interest is focused on nutrient function within

cells at the molecular level, the interactions between various

nutri-ents, and the identification of other protective factors in certain

foods All of the answers are not in, but sufficient evidence is

available to provide us with some useful, prudent guidelines for

healthful eating practices

Over the past two decades, in response to the need for healthier

diets, a variety of public and private health organizations

ana-lyzed the research relating diet to health and developed some basic

guidelines for the general public The details underlying these

recommendations may be found in several voluminous

govern-mental reports, most recently the totally revamped eighth edition

of Nutrition and Your Health: Dietary Guidelines for Americans,

released by the U.S Departments of Agriculture and Health and

Human Services in 2015 and Healthy People 2020 These reports

serve as the basis for dietary guidelines in ChooseMyPlate

Additionally, governmental health agencies in other countries,

such as Britain, Canada, Germany, Japan, and Mexico, have

devel-oped dietary guidelines for health promotion in their countries, as

has the WHO on a global basis Several health organizations have

promoted diets to help prevent specific diseases The American

Heart Association released a set of dietary guidelines to help

pre-vent heart disease, the American Cancer Society released a similar

set to help prevent cancer, and the American Diabetes Association

did likewise for prevention of diabetes In its recent position

state-ment, headed by Freeland-Graves, the Academy of Nutrition and

Dietetics supported the position that the total diet or overall

pat-tern of food eaten is the most important focus of healthy eating

Classification of specific foods as good or bad is overly simplistic

and can foster unhealthy eating behaviors The Academy noted

that all foods can fit within the total diet approach if consumed

in moderation with appropriate portion size and combined with

physical activity Healthy eating messages should emphasize a

balance of food and beverages within energy needs, rather than

any one food or meal

The dietary guidelines promoted by these government and

professional health organizations have much in common and are

related to some of the diet plans we will discuss in subsequent

chapters, notably the Mediterranean diet and the DASH diet For

example, Sofi’s review indicated that the Mediterranean diet has

been consistently shown to be associated with favorable health

outcomes and a better quality of life Details are presented in a

new book by Barry Sears, The Mediterranean Zone: Unleash the

Power of the World’s Healthiest Diet for Superior Weight Loss,

Health, and Longevity.

Although we do have considerable research to support dietary

recommendations to promote health, the research is incomplete

Moreover, inconsistencies in research findings, such as the health

effects of saturated fat, discussed later in this chapter, may affect

recommendations Thus, the following recommendations may be

considered to be prudent, and throughout this book we will refer to

www.dietaryguidelines.gov The Dietary Guidelines for

Americans 2015 focus on the total diet and how to integrate

all of the recommendations into practical terms, encouraging personal choice but result in an eating pattern that is nutrient dense and Calorie balanced

www.ChooseMyPlate.gov ChooseMyPlate offers ized eating plans and interactive tools to help you plan your

personal-food choices based on Dietary Guidelines for Americans

Click on SuperTracker, a series of applications including Daily Food Plans for planning a healthy diet

Cancer In its recent extensive worldwide report on the means to prevent cancer, the American Institute of Cancer Research high-lighted the three most important means to prevent a wide variety

of cancers, and all are related to exercise and nutrition:

∙ Choose mostly plant foods, limit red meat, and avoid processed meat

∙ Be physically active every day in any way for 30 minutes or more

∙ Aim to be a healthy weight throughout life as much as possible

Brain Health Meeusen noted that exercise and nutrition clearly are both powerful means to positively influence the brain and may influence brain health through several mechanisms that create new neurons (neurogenesis) In their review, Gomez-Pinilla and Hillman cite recent studies indicating that exercise collaborates with other aspects of lifestyle to influence cognition In particular, select dietary factors share brain-enhancement mechanisms simi-lar to exercise, and in some cases can complement the action of exercise They conclude exercise and diet appear to be an effective strategy to counteract neurological and cognitive disorders

Prevention of chronic diseases is a high priority for most ernmental and professional health organizations, and they have developed appropriate healthy lifestyle behaviors to maximize prevention efforts Most such healthy lifestyle behaviors include exercise and healthful eating The possible complementary effect

gov-of exercise and nutrition on chronic diseases will be presented in later chapters as appropriate In particular, as will be discussed

in chapter 10, the most significant adverse health effect resulting from the combination of a poor, hypercaloric diet and physical inactivity is obesity, which may be involved in the etiology of numerous chronic health diseases

Am I eating right?

As part of this course, you may be required to document your

actual food intake for several days and then conduct a

comput-erized dietary analysis to determine your nutrient intake Many

computerized dietary analysis programs assess the quality of your

diet from a health perspective and make recommendations for

improvement where necessary

For the time being, you may wish to take the brief diet

quiz-zes in the Application Exercise at the end of this chapter to

pro-vide you with a general analysis of your current eating habits

Moreover, you may also analyze your diet at the ChooseMyPlate

Website Although more detailed information on healthy eating is

presented in subsequent chapters, these application exercises may

help you obtain some useful preliminary information on the

over-all healthfulness of your current diet

Are there additional health benefits when both

exercise and diet habits are improved?

A poor diet and physical inactivity are individual major risk factors

for the development of chronic diseases Collectively, however,

they may pose additional risks, particularly prediabetes, a

condi-tion preceding type 2 diabetes, and for the two most deadly chronic

diseases—heart disease and cancer Recent research also indicates

certain that dietary factors may complement exercise for enhanced

brain function Thus, combining a recommended exercise program

with a healthy diet may have additive effects on one’s health

Prediabetes Several factors, such as excess body weight, impaired

fasting blood glucose, and glucose intolerance, may be associated

with prediabetes and predispose one to type 2 diabetes In their

recent review, Aguiar and others concluded that prevention

interven-tions that include diet and both aerobic and resistance exercise

train-ing are modestly effective in reductrain-ing risk factors associated with

prediabetes in adults, which help in the prevention of type 2 diabetes

Heart Disease Lloyd-Jones and others, discussing the American

Heart Association’s Strategic Impact Goal through 2020 and

beyond, reported that ideal cardiovascular health is associated with

physical activity at goal levels and pursuit of a diet consistent with

current guideline recommendations As indicated in table  1.2,

which highlights risk factors for heart disease, the key lifestyle

behaviors that may be effective in favorably modifying heart

dis-ease risk factors are proper nutrition and exercise Moreover,

sev-eral of the risk factors for heart disease are diseases themselves,

such as diabetes, obesity, and high blood pressure, all of which

may benefit from the combination of proper nutrition and exercise

www.healthcanada.gc.ca The Canada Food Guide, Eat Well

and Be Active Educational Toolkit provides excellent

informa-tion on healthy eating Click on Food and Nutriinforma-tion

www.eatright.org The Academy of Nutrition and Dietetics site

provides numerous tips to eating healthy Click on Public for

various topics for eating healthy, such as Eat Right on a Budget.

Risk Factors Classification

Positive Health Lifestyle Modification

High blood pressure Major Proper nutrition, aerobic exercise High blood lipids Major Proper nutrition, aerobic

exercise

loss, aerobic exercise Stressful lifestyle Contributory Stress management Dietary intake Contributory Proper nutrition

TABLE 1.2 Modifiable risk factors associated

with coronaryheart disease

software Nurture involves not only exposure to the sport at a cific time but expert training as well But Ahmetov and Rogozkin indicate that optimal responses to training are also dependent on possession of appropriate genes Genes explain why some individu-als benefit while others do not from the same sport training program Elite athletes are not only born with the right genes for a given sport but must also have the right genes to benefit from proper training Moreover, Joyner and Coyle note that complex motivational and sociological factors also play important roles in who does or does not become a sport champion For example, one is more likely to

spe-be successful in ice hockey if born in Canada rather than Brazil, but the Brazilian child may be more successful in soccer

What is sports-related fitness?

One of the key factors determining success in sport is the ability

to maximize your genetic potential with appropriate physical and mental training to prepare both mind and body for intense compe-

tition In this regard, athletes develop sports-related fitness, that

is, fitness components such as strength, power, speed, endurance, and neuromuscular motor skills specific to their sport

The principles of exercise training introduced earlier, such as overload and specificity, are as applicable to sports-related fitness

as they are to health-related fitness However, training for sports performance is more intense, prolonged, and frequent than training for health, and training is specific to the energy demands and skills associated with each sport We will discuss energy expenditure for sports performance in chapter 3, but here are some examples of sport events with varying rates of energy expenditure or energy needs:

∙ Explosive, power sports – Olympic weight lifting

∙ Very high-intensity sports – 100-meter dash

∙ High-intensity, short duration sports – 5,000-meter run (3.1 miles)

∙ Intermittent high-intensity sports – Soccer

∙ Endurance sports – Marathon running (26.2 miles; 42.2 kilometers)

∙ Low-endurance, precision skill sports – Golf

∙ Weight-control and body-image sports – Bodybuilding

Training of elite athletes at the United States Olympic Training Center (USOTC) focuses on three attributes:

∙ Physical power

∙ Mental strength

∙ Mechanical edgeCoaches and scientists work with athletes to maximize physi-cal power production for their specific sport, to optimize mental strength in accordance with the psychological demands of the sport, and to provide the best mechanical edge by improving spe-cific fitness and sport skills, sportswear, and sports equipment Jay Kearney, former senior sports scientist at the USOTC, has

However, although appropriate lifestyle behaviors, such as

exer-cise, a healthful diet, and maintaining a healthy body weight, may

help prevent the development of chronic diseases, individuals with

a strong genetic predisposition to various risk factors, such as high

serum cholesterol levels and high blood pressure, or those who are

nonresponders to exercise or diet changes, may need medication to

reduce these to a level compatible with protective effects

Ke y C o n c e p t s

c The primary purpose of the food we eat is to provide us with

nutrients essential for the numerous physiological and

bio-chemical functions that support life

c Dietary guidelines developed by major professional health

organizations are comparable, and collectively help prevent

major chronic diseases such as heart disease, cancer,

diabe-tes, high blood pressure, and obesity

c Poor eating habits span all ages The Dietary Guidelines for

Americans and the Healthy People 2020 report note that

poor nutrition is a major health problem in the United States

c Basic guidelines for a Prudent Healthy Diet include

mainte-nance of a proper body weight and consumption of a wide

variety of natural foods rich in nutrients associated with

health benefits The more healthful dietary guidelines that

you adopt, the greater will be your overall health benefits

c Although both proper exercise and sound nutrition habits

may confer health benefits separately, health benefits may

be maximized when both healthy exercise and nutrition

life-styles are adopted

C h e c k f o r Yo u r s e l f

c As a prelude to activities presented in later chapters, make

a detailed record of everything you eat for a full day, from

breakfast until your late snack at night

Sports-Related Fitness:

Exercise and Nutrition

As with health, genetic endowment plays an important underlying

role in the development of success in sport In his book The Sports

Gene, senior writer for Sports Illustrated and former college

run-ner David Epstein notes that nature and nurture are both essential

ingredients for superior performance in a given sport Nature is in

the genes, the hardware, whereas nurture is in the environment, the

www.fitness.gov/ The President’s Council on Fitness,

Sports, & Nutrition provides guidelines for children and adults

to Be Active and Eat Healthy

www.choosemyplate.gov/downloads/SuperTrackerHS

LessonPlans1.pdf For teachers, this site presents lesson

plans for promoting healthy nutrition among high school

students using SuperTracker

As we shall see, there are various dietary factors that may ence biomechanical, psychological, and physiological consider-ations in sport For example, losing excess body fat will enhance biomechanical efficiency; consuming carbohydrates during exer-cise may maintain normal blood sugar levels for the brain and pre-vent psychological fatigue; and providing adequate dietary iron may ensure optimal oxygen delivery to the muscles All these sports nutrition factors may favorably affect athletic performance.

influ-Sports nutrition involves the application of nutritional

prin-ciples to enhance athletic performance Louise Burke, an tionally renowned sports nutritionist from Australia, defined sports nutrition as the application of eating strategies with several major objectives:

interna-∙ To promote good health

∙ To promote adaptations to training

∙ To recover quickly after each training session

∙ To perform optimally during competitionSports nutritionists may meet these objectives in various ways, such as developing meal plans for training, recovery, and com-petition; providing appropriate information about healthy diets;

discussing the efficacy, safety, and permissibility of sports ments; counseling individual athletes with special diets, such as vegetarians; and monitoring athletes for weight loss and eating disorders

supple-Although investigators have studied the interactions between nutrition and various forms of sport or exercise for more than a hundred years, it is only within the past several decades that exten-sive research has been undertaken regarding specific recommen-dations for athletes

Is sports nutrition a profession?

Sports nutrition is recognized as an important factor for optimal athletic performance Sports nutrition is sometimes referred to as

exercise nutrition when coupled with exercise designed for related fitness, as discussed in the previous section, but that term is less frequently used Several factors indicate that sports nutrition has become a profession and is a viable career opportunity

health-Professional Associations Several professional associations, such as the Sports and Cardiovascular Nutritionists (SCAN) sub-section of the Academy of Nutrition and Dietetics, Professionals

in Nutrition for Exercise and Sport (PINES), the Collegiate &

Professional Sports Dietitians Association (CPSDA), and the International Society of Sports Nutrition (ISSN), are involved in the application of nutrition to sport, health, and wellness

Certification Programs Several professional and sports- governing organizations have developed a recognized course of study or certification program to promote the development of pro-fessionals who can provide athletes with sound information about nutrition For example, the Academy of Nutrition and Dietetics has established a program for certification as a Specialist in Sports Dietetics (CSSD), while the International Olympic Committee offers a diploma in sports nutrition

noted that sports science and technology provide elite competitors

with the tiny margins needed to win in world-class competition

(figure 1.8)

Athletes at all levels of competition, whether an elite

inter-national competitor, a college wrestler, a high school baseball

player, a seniors age-group distance runner, or a youth league

soc-cer player, can best improve their sports-related fitness and

per-formance by intense training appropriate for their age, physical

and mental development, and sport For example, in a review as

to how we should spend our time and money to improve cycling

performance, Jeukendrup and Martin indicated that, of the many

ways possible, training is the first and most effective means To

paraphrase Theodore Roosevelt, “Do the best with what you got.”

However, sports and exercise scientists have investigated a

num-ber of means to improve athletic performance beyond that

attribut-able to training, and one of the most extensively investigated areas

has been the effect of nutrition

What is sports nutrition?

At high levels of athletic competition, athletes generally receive

excellent coaching to enhance their biomechanical skills

(mechan-ical edge), sharpen their psycholog(mechan-ical focus (mental strength),

and maximize the physiological functions (physical power)

essen-tial for optimal performance Clyde Williams, a renowned sport

scientist from England, notes that, in addition to specialized

train-ing, from earliest times certain foods were regarded as essential

preparation for sports competition, including the Olympics in

ancient Greece

F I G U R E 1 8 Elite athletes are exposed to state-of-the-art

physiological, psychological, and biomechanical training that may

provide an advantage measured in milliseconds, which could

mean the difference between the gold and silver medal in

world-class competition

Are athletes today receiving adequate nutrition?

Numerous survey studies regarding dietary intake

of athletes have been conducted over the course of the past two decades and, in general, present mixed results Based on recommended dietary practices for athletes, the following is a brief summarization

∙ Athletes involved in weight-control sports who may restrict energy intake may be at high risk for micronutrient deficien-cies Iron and calcium deficiencies may be common in female athletes

∙ Many athletes, including youth athletes, take dietary ments, not only vitamins and minerals to help prevent deficien-cies but also supplements designed to enhance performance.This brief review indicates that some athletic groups are not receiving the recommended allowances for a variety of essential nutrients or may not be meeting certain recommended standards

supple-It should be noted, however, that these surveys have analyzed the diets of the athletes only in reference to a standard, such as the RDA, and many studies have not analyzed the actual nutrient or biochemical status (such as by a blood test) of the athlete or the effects that the dietary deficiency exerted on exercise performance capacity or sport performance The RDA for vitamins and min-erals incorporates a safety factor, so an individual with a dietary intake of essential nutrients below the RDA may not necessar-ily suffer a true nutrient deficiency If, however, the athlete does develop a nutrient deficiency, then athletic performance may dete-riorate and health may be impaired Examples discussed in later chapters include impaired aerobic endurance capacity associated with iron deficiency and premature decreases in bone density with calcium deficiency

Why are some athletes malnourished?

Studies over the course of the past two decades have indicated

a variety of factors that may contribute to poor dietary habits in many athletes, including the following:

∙ Athletes may not possess sufficient knowledge to make priate food choices

appro-∙ Christine Rosenbloom, a distinguished sports nutritionist, and her colleagues indicate that athletes have misconceptions about the roles of specific nutrients in sport performance, and if they choose foods based on these misconceptions then sports perfor-mance may suffer

∙ Athletes may not be getting sound sports nutrition information Jacobson and others reported that although some college varsity

Research Productivity Numerous exercise-science/nutrition

research laboratories at major universities are dedicated to sports

nutrition research Almost every scientific journal in sport/exercise

science, and even in general nutrition, appears to contain at least one

study or review in each issue that is related to sports nutrition Several

journals, such as the International Journal of Sport Nutrition and

Exercise Metabolism, focus almost exclusively on sports nutrition

International Meetings Numerous international meetings have

focused on sports nutrition, some meetings highlighting

nutri-tional principles for a specific sport, such as soccer or track and

field, while others may focus on a specific sport supplement, such

as creatine

Consensus Statements and Position Stands Several

interna-tional sports-governing organizations have developed consensus

statements on nutrition for their specific sport For example, the

International Swimming Federation (Fédération Internationale

de Natation, FINA) recently published a consensus statement on

nutrition for the aquatic sports, which is designed to provide sound

nutrition information for aquatic athletes worldwide A more

gener-alized position stand entitled “Nutrition and Athletic Performance”

was issued jointly by the American Dietetic Association (now the

Academy of Nutrition and Dietetics), Dietitians of Canada, and

the American College of Sports Medicine

National Sports Nutrition Programs Many countries have

developed sports nutrition programs for international competition,

such as the Olympic Games Burke and others reported on such

programs for the London Olympic Games

Career Opportunities Sports nutritionists are employed by

professional sport teams and athletic departments of major

uni-versities to design optimal nutritional programs for their athletes

Some dietitians market themselves as full-time or part-time sports

nutritionists within their communities Many are members of

CPSDA

Sports nutrition as we know it today has a relatively short

his-tory, but it appears to be an important aspect in the total

prepara-tion of the athlete

www.acsm.org You may access the position stand entitled

“Nutrition and Athletic Performance” by clicking on Access

Public Information and then Position Stands

www.scandpg.org/sports-nutrition/be-a-board-certified-sports-dietitian-cssd/ Check this SCAN site to see what

is necessary to become a Certified Specialist in Sports

Dietetics

www.sportsoracle.com Check this PINES site to see what

is needed to become a member and the requirements for the

IOC Diploma in Sports Nutrition

www.sportsrd.org Check this CPSDA site for information

on membership