Chapter 15 Fitness: Physical Activity, Nutrients, and Body...

Enriched Instructor’s Manual to Accompany Understanding Nutrition, First Canadian Edition 15-1

Chapter 15Fitness: Physical Activity, Nutrients, and Body Adaptations

I F N O T H I N G E L S E , M Y S T U D E N T S S H O U L D L E A R N …

1. That regular physical activity benefits a person physically, psychologically, and socially. In addition, the student should learn the different components of fitness (flexibility, strength, muscular endurance, and cardiorespiratory endurance) that improves with training.

2. That the macronutrients (carbohydrates, lipids, protein) function as fuel sources for the body’s cells in order to sustain metabolic activity during rest and increased physical activity. The relative use of each fuel source will depend on the intensity and duration of the physical activity.

3. That the micronutrients (vitamins and minerals) do not provide energy to sustain the body’s metabolic needs, but are essential for the body to draw energy from the macronutrients.

4. There is a multitude of supplements on the market that claim to enhance physical activity and exercise performance. When evaluating the individual supplements, it is important for the student to base decisions on their knowledge of the metabolic pathways in which the body harnesses energy from the macronutrients.

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

Students should be able to:

• LO 15.1: Discuss the shortterm and longterm benefits of achieving cardiorespiratory and muscular fitness. [Remember/Understand]

• LO 15.2: Explain how Canada’s Physical Activity Guide can be incorporated into anyone’s lifestyle, and to suggest simple ways to increase activity levels throughout the day. [Understand/Apply]

• LO 15.3: Describe the energy systems the human body uses to support cellular activity during exercise, including the use of adenosine triphosphate and creatine phosphate. [Understand/Remember]

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• LO 15.4: Explain why it is important for an athlete to maintain blood glucose levels before, during, and after vigorous exercise. [Understand]

• LO 15.5: Describe how the body uses fat as an energy substrate during exercise, and how exercise duration and intensity affects fat usage. [Understand]

• LO 15.6: Describe how an elite athlete’s body uses dietary protein during and after strenuous exercise. [Understand]

• LO 15.7: Discuss some reasons why female endurance athletes may be vulnerable to iron deficiency. [Analyze]

• LO 15.8: Discuss the potential benefits of vitamin supplementation may have on athletic performance, as well as the supplements that demonstrate contrary research findings. [Understand/Analyze]

• LO 15.9: Describe the potential danger of exercise in hot and humid environments and why fluid replacement is critically important. [Understand/Apply]

• LO 15.10: Evaluate the usefulness of different beverages (i.e., carbohydrateelectrolyte sports drinks, alcohol, caffeine) on exercise performance. [Understand/Apply]

• LO 15.11: Describe the key components to be considered when developing a beneficial and healthy diet for the physically active individual. [Evaluate/ Create]

• LO 15.12: Evaluate whether conjugated linoleic acid (CLA) and other ergogenic aids are useful for obtaining an ideal body composition for sports. [Evaluate/Create]

W H Y I S T H I S C H A P T E R I M P O R TA N T T O S C I E N T I S T S A N D H E A LT H C A R E P R AC T I T I O N E R S ?

“Of special interest to...” symbol key: = HealthCare Practitioners = Science Majors

1. Scientists are studying the effects of vitamin supplements on performance. Vitamin E supplementation protects against oxidative damage caused by physical activity and may reduce fatigue. Iron is important due to its place in hemoglobin and its role in oxygen delivery. Thus, supplementation is recommended for people with irondeficiency anemia.

2. Scientists recognize that fluid intake can affect physical performance and are conducting studies to examine this and to compare the efficacy of sports drinks compared to water for rehydrating athletes. Healthcare practitioners routinely

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advise their patients who engage in exercise to ensure that they consume copious amount of water before, during, and after the activity.

3. There is ongoing research into the effects of harmful dietary practices (i.e.,

restricting caloric intake, not receiving the right amount of nutrients, insufficient calcium intake) on bone health and athletic performance.

4. To date, studies have been carried out that examine the nutrition knowledge of female collegiate athletes. Future research is needed to examine the effectiveness of nutritional counselling on female collegiate athletes who are at risk for developing eating disorders. Adolescent and young adult women who engage in competitive athletics are often advised by their healthcare providers to ensure appropriate and adequate dietary practices that are proportional to their level of exercise.

5. There are many products promoted on the market as ergogenic aids. Scientists

examine the benefits (improved endurance, increased muscle mass, a reduction in infection etc.,) and disadvantages (e.g., health risks) of short term and prolonged use of these substances (see Highlight 15).

W H Y S H O U L D S T U D E N T S C A R E ?

• Physical activity and fitness benefit people’s physical and psychological wellbeing and improves their resistance to disease. Everyone should be encouraged to participate in regular physical activity. Benefits include a more restful sleep, better nutritional health, improved body composition, improved bone density, enhanced resistance to colds and other infectious diseases, lower risks of some types of cancers, stronger circulation and lung function, lower risks of cardiovascular disease, lower risks of type 2 diabetes, reduced risk of gallbladder disease (women), lower incidence and severity of anxiety and depression, strong self image and a longer, high quality of life.

• Students should learn about the different components of physical fitness (flexibility, muscle strength, muscle endurance, and cardiorespiratory endurance), as well as the benefits of participation in various types of physical activity. Muscles adapt to the activities they are called upon to perform repeatedly.

• Cardiorespiratory endurance training enhances the ability of the heart and lungs to deliver oxygen to the muscles. With cardiorespiratory endurance training, the heart becomes stronger, breathing becomes easier at the same level of work, and the health of the entire body improves.

• Weight training offers health and fitness benefits such as increasing muscle strength, improving physical mobility, and maximizing and maintaining bone mineral density.



• Students should be aware that the intensity and duration of an activity determine the types of fuels that are used.

– Glucose is supplied by dietary carbohydrate or made by the liver. It is stored in both liver and muscle tissue as glycogen and is called upon during physical activity. Total glycogen stores affect an athlete’s endurance.

– The more intense the activity is, the more glucose is demanded by the body. During anaerobic metabolism, the body spends glucose rapidly and accumulates lactic acid. Low to moderate intensity exercise enhances fat metabolism.

– Physical activity of long duration places demands on the body’s glycogen stores. Carbohydrate ingested before and during longduration activity may help to forestall hypoglycemia and fatigue.

– The extent of training also plays a role in fuel metabolism. Highly trained muscles use less glucose and more fat than do untrained muscles to perform the same work, so their glycogen lasts longer.

• Students should be aware that there are ways in which an athlete can manipulate the amount of glycogen stored in the muscles. Carbohydrate loading is a regimen of physical activity and diet that enables an athlete’s muscles to store largerthannormal amounts of glycogen to extend endurance. After strenuous training, eating foods with a high glycemic index may help restore glycogen rapidly.

• Athletes who eat highfat diets may burn more fat during endurance activity, but the risks to health outweigh any possible performance benefits. The intensity and duration of activity, as well as the degree of training influence fat utilization.

• Physical activity stimulates muscle cells to break down and synthesize protein, resulting in muscle adaptation to activity. Athletes use protein both for building muscle tissue and for energy. Diet, intensity, and duration of training affect protein use during activity.

• Vitamins are essential for releasing the energy trapped in energyyielding nutrients and for other functions that support physical activity. Active people can meet their vitamin needs if they eat enough nutrientdense foods to meet their energy needs.

• Students should be aware of the adverse effects of exercise in environmental extremes:

– Hypothermia threatens those who exercise in the cold.– Heat stroke can be a threat to physically active people in hot, humid weather.

Symptoms of heat stroke include headache, nausea, dizziness, clumsiness, stumbling, sudden cessation of sweating, internal temperature above 40°C (104°F), and confusion or loss of consciousness.

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• It is important for students to understand that physically active people lose fluids and must replace them to avoid dehydration. The following are some guidelines to keep in mind:

– Thirst indicates that water loss has already occurred. Water is the best drink for most physically active people, but endurance athletes need drinks that supply glucose as well as fluids.

– The body adapts to compensate for sweat losses of electrolytes. Athletes are advised to use foods, not supplements, to make up for these losses.

– During events lasting longer than three hours, athletes need to pay special attention to replacing sodium losses to prevent hyponatremia.

– Caffeinecontaining drinks within limits may not impair performance, but water and fruit juice are preferred. Alcohol use can impair performance in many ways and is not recommended.

W H AT A R E C O M M O N S T U D E N T M I S C O N C E P T I O N S / S T U M B L I N G B L O C K S ?

1. Many students who study nutrition do not have a background in exercise science. Thus, they have a great deal of difficulty understanding energy metabolism during physical activity and what constitutes aerobic and anaerobic activities. Classroom Activity 152 is very helpful in this regard.

2. Some students erroneously think that you need to participate in prolonged activities (i.e., run a marathon) in order to gain health benefits from physical activity. The Canadian Society of Exercise Physiologists recommends that Canadians should try to get at least 150 minutes of moderate to vigorousintensity physical activity per week. (This translates to 30 minutes of exercise performed 5 days/week).

3. Some students, who are also athletes, take supplemental vitamins in the hope of improving performance. Nutrient supplements do not enhance performance; however, vitamin deficiency can impede performance.



W H AT C A N I D O I N C L A S S ?

There are a variety of activities that can be done in class. Listed below are some activities that will help introduce the topic of nutrition, and the students to each other.

Classroom Activity 151: ChapterOpening QuizObjective: Introduction to chapter Class size: Any

Instructions: As a way of introducing any new chapter, give a quiz to the class. This is a quiz designed to be projected overhead. For details, please see Chapter 1, Classroom Activity 14.

Classroom Activity 152: Physical Activity DiaryKey concept: Evaluation of physical activity Class size: Any

Instructions: Instruct students to keep an activity log or diary in which they can record physical activities they participate in daily. Have them keep the record for seven days, and ask them to bring the record to class. Divide students into groups and have them evaluate their activity patterns. (You could use Worksheet 153 in conjunction with this activity.)

Classroom Activity 153: Sports Drinks EvaluationKey concepts: Maintaining hydration, sports drinks composition Class size: Any

Instructions: Have students research four to six different sports drinks. Have them list the amount of glucose, sodium, and other electrolytes present in each product. Instruct students to list the advantages and disadvantages of these products in addition to water and provide their recommendations about the best choice. Discussion can progress regarding cost of the sports drinks as well as taste.

Classroom Activity 154: Fitness Quackery EvaluationKey concept: Evaluation of fitness information from the mediaClass size: Medium to small

Instructions: For a fitness quackery activity, ask students to bring in newspaper and magazine advertisements and brochures for food supplements and products they believe represent exercise and fitness quackery. Ask what characteristics of the advertisement led them to this conclusion, and whether the use of this food product might pose a danger to one’s health. The importance of this activity is that this is an area of quackery that has become a booming business in North America. As consumers, students not only should be aware that these problems exist but should know how to distinguish between healthpromoting products and those that are fraudulent.

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Classroom Activity 155: Fitness Facility EvaluationKey concept: Evaluation of fitness facilities Class size: Any

Instructions: Instruct students to visit a local fitness facility and investigate the dietary advice they offer as part of the service. Do they sell nutrient supplements? What qualifications or training in nutrition do the fitness instructors have?

Classroom Activity 156: Enhancing Understanding of Metabolism1*Key concept: Metabolism basics Class size: Any

Instructions: To explain human metabolism, an analogy based on the automobile can be offered. The oxidation of gasoline produces heat and energy (measured in kilometres per litre) and carbon dioxide and water are waste products. Nutrients and gasoline are both fuels that are oxidized in the presence of oxygen to produce energy, carbon dioxide, and water.

Ask students to consider a car having a manual transmission with only two gears: first and high. First gear is beneficial for rapid acceleration. If you do not shift out of first gear, the car will no longer accelerate, and it will use gasoline very inefficiently. You must shift into high gear to keep the car running efficiently at a higher speed. Human beings obtain energy from two analogous processes: glycolysis and the TCA cycle. Anaerobic glycolysis serves the need for quick energy to accomplish an intense activity for a short duration of time. For endurance activities, additional energy must be obtained from the TCA cycle. Explain that the choice of activity determines the proportion of fat and glucose burned during the activity.

Energy Obtained

Measure of Energy Advantage Disadvantage

Car First gear km/L Quick acceleration Can only be used for a few seconds of acceleration

Human beings

Glycolysis anaerobic

ATP Quick, intense muscle activity Can only be used for a few seconds as lactic acid is produced

Car High gear km/L Used to sustain desired velocity over maximum amount of time

Depends on rate of oxygen delivery to fuel source; better tuned engines achieve maximum km/L

Human beings

TCA cycle aerobic

ATP Used to sustain desired amount of muscle activity over maximum amount of time

Depends on rate of oxygen delivery to fuel source; better conditioning improves rate of oxygen delivery

Critical Thinking Questions2

These questions will also be posted to the book’s website so that students can complete them online and email their answers to you.

1 Activity provided by Samantha Logan, DrPH, University of Massachusetts, Amherst.

2 Contributed by Kathleen Rourke.



1. As discussed in this chapter, there are many benefits of physical activity. For patients participating in a weightloss program, what are some of the benefits of physical activity that a patient might gain greater benefit from, and in what areas might the dietitian want to be more cautious and provide more frequent assessments?

2. Discuss the body’s use of highenergy compounds and energy nutrients during physical activity. In other words, differentiate between an athlete’s energy needs for shortdistance and sprint events versus endurance events.

3. Manufacturers of sports drinks select top athletes to speak in commercials for this multibillion dollar business. In your opinion, are the benefits of sports drinks worth their cost? There is no right or wrong answer!

4. As your chapter points out, physical activity provides many great benefits for an individual’s cardiovascular and respiratory systems and emotional wellbeing, and helps to maintain their bone health and flexibility. Yet, exercises done improperly can be harmful to an individual, and there are also many products on the market that are promoted to improve a person’s game—products that may truly have no value. Imagine yourself as a famous sports dietitian with a broad clientele. Discuss areas of concern that you would need to address with the following patients. These are two vary different athletes who are motivated and working hard. What are your assessment concerns for each, what are your recommendations, and why?

(a) A 45yearold male “weekend warrior” has decided to return to his favourite sport of running to get back into shape and lose some weight. At present, he is 9 kilograms (20 pounds) overweight and has not been to his physician for about 1.5 years, but he states he was in perfect health at that time. He has decided to go on a popular highprotein diet to help hasten his weight loss and support tissue repair from the running. His eating plan includes protein bars, protein shakes, and protein water drinks. He is also taking chromium, zinc, vitamins C and E, and tryptophan supplements. He is presently running 5 kilometres (3 miles) a day, 4 days a week, and 16 kilometres (10 miles) a day, 2 days a week. His goal is to be able to do a marathon in six months.

(b) Your second paient is a worldclass female figure skater aged 13 years. At present, she is 1.58 m (5 2 ) tall and weighs 43 kilograms (95 pounds). She has not started′ ″ her menstrual cycle but appears to be in Tanner stage 5 or full sexual development. Her coach does not want her to gain any further weight for her height; however, if she does get taller, then he may be amenable. Her diet is approximately 60 percent protein, 35 percent carbohydrate, and 5 percent fat. She eats lean meats but tries to stay with the vegetarian proteins, complex carbohydrates, and monounsaturated fatty acids. She is very motivated about her diet and her mother is constantly watching her as well as her coach. She does eat salads and fruits and, of course, exercises or works out approximately 10 hours a day, if not more at times. Along with diet, this athlete consumes unknown supplements and ergogenic aids to support her athletic training. At her young age, she has won several world championships and is considered the next Olympic

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gold medal champion. The Olympics are two years away and she is highly motivated to be there and win.

5. Differentiate between moderateintensity and vigorousintensity aerobic activity. How does “the overload principle” impact the outcome of the physical activity that an individual participates in?

W H AT O T H E R R E S O U R C E S A R E AVA I L A B L E ?

You can look up information about government policy as well as any health condition that you are interested in learning more about. Consult the following websites to get reliable information on the following:

• Assess yourself at Dietitians of Canada (DC): www.dietitians.ca/public/content/eat_well_live_well/english/eatracker.

• Visit Coalition for Active Living (CAL) website: http://www.activeliving.ca.

• Canadian Fitness and Lifestyle Research Institute—this national research agency bridges the gap between knowledge and behaviour on physical activity and educates Canadians about the importance of living a healthy and active lifestyle: http://www.cflri.ca

• Visit Coaching Association of Canada, a notforprofit amateur sport organization which has a mandate to improve the effectiveness of coaching across all levels of the sport. Click on Sport Nutrition for their current nutritionrelated resources written for coaches and parents: http://www.coach.ca

• Health Canada’s Natural Health Products Directorate is available at www.hcsc.gc.ca/ahcasc/branchdirgen/hpfbdgpsa/nhpddpsn/indexeng.php

• Health Canada. Eating Well with Canada’s Food Guide. Food Guide Basics – Choosing Beverages. Available at http://www.hcsc.gc.ca/fnan/foodguidealiment/choosechoix/beverageboisson/indexeng.php

• Find out more about physical activity levels of Canadians at http://www.cflri.ca/eng/levels/adult_levels.php

• Canadian Health Measures Survey provides information on cardiorespiratory and musculoskeletal fitness of Canadians. This information can be found at http://www.statcan.gc.ca/dailyquotidien/100113/dq100113aeng.htm

• Physical activity information that is posted by the Public Health Agency of Canada can be found at http://www.phacaspc.gc.ca/hpps/hlmvs/paggap/indexeng.php.

• Learn more about the recommendations made by the Canadian Society of Exercise Physiology at http://www.csep.ca/english/view.asp?x=804


http://www.dietitians.ca/public/content/eat_well_live_well/english/eatracker

http://www.csep.ca/english/view.asp?x=804

http://www.phac-aspc.gc.ca/hp-ps/hl-mvs/pag-gap/index-eng.php

http://www.phac-aspc.gc.ca/hp-ps/hl-mvs/pag-gap/index-eng.php

http://www.statcan.gc.ca/daily-quotidien/100113/dq100113a-eng.htm

http://www.cflri.ca/eng/levels/adult_levels.php

http://www.hc-sc.gc.ca/fn-an/food-guide-aliment/choose-choix/beverage-boisson/index-eng.php

http://www.hc-sc.gc.ca/fn-an/food-guide-aliment/choose-choix/beverage-boisson/index-eng.php

http://www.hc-sc.gc.ca/ahc-asc/branch-dirgen/hpfb-dgpsa/nhpd-dpsn/index-eng.php

http://www.hc-sc.gc.ca/ahc-asc/branch-dirgen/hpfb-dgpsa/nhpd-dpsn/index-eng.php

http://www.coach.ca/

http://www.cflri.ca/

http://www.activeliving.ca/


A N S W E R K E Y F O R A L L I N S T R U C T O R ’ S M A N UA L AC T I V I T I E S

Critical Thinking Questions3

These questions will also be posted to the book’s website so that students can complete them online and email their answers to you.

1. Answer: A patient undergoing weight loss can often benefit even more from the advantages of physical activity. For instance, physical activity can help to enhance selfesteem and reduce anxiety and depression—aspects especially important in the individual who is overweight. Individuals who suffer from anxiety or depression do benefit from exercise. Imagine the individual who is obese and eats as a result of anxiety or depression. What a benefit exercise or physical activity can make for anxiety and depression as well as weight and weight loss. Physical activity can dissipate stress hormones. This can be so helpful for the obese individual that learned to eat in response to stress.

If an individual’s selfesteem has been lowered because of he or she is overweight, exercise can generally help to improve selfesteem and reduce stress.

Many chronic diseases such as cardiovascular disease, including poor circulation and lung function, and type 2 diabetes can be reduced or at times managed with physical activity. Obesity is a major determinant of these diseases. Physical activity can postpone or prevent their onset, depending on many factors including genetics, progression of the disease, need to lose weight, and amount of weight lost, etc. When comparing two individuals with one of these chronic diseases, one who exercises and one who does not, the one who exercises will do significantly better than the one who does not. Exercise does have to be at the intensity, duration, and frequency necessary to render an overload outcome at each session to achieve a fitness level and body fat level appropriate for height, age, and health conditions.

Resistance from colds, other infections, and perhaps cancer: An individual who is in better health and consumes a nutrientdense diet is more able to resist infections and other health issues. Often, while obese individuals appear to be well fed, they are not eating nutrientdense foods, leading to malnutrition of sorts. A weightloss program that provides nutrientdense foods actually improves immune function for the patients and optimal health for resisting colds, other infections, and perhaps cancer.

Gallbladder: This organ functions by storing bile to break down fatty acids. In the obese patient, a diet high in fatty acids may overload the gallbladder. When these patients start to consume a diet that is proportioned with less fat and far less saturated fat, the gallbladder is eased of its load and gallbladder disease can be reduced.

Body composition: This is directly related to longevity via BMI and body fat. The obese individual retains a higher BMI and higher percentage of body fat, both correlated with a lower life span. Weight loss can improve not only one’s body

3 Contributed by Kathleen Rourke.

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composition but also life expectancy, ability to move and exercise, chronic disease outcomes, and one’s overall life. Seems like a great deal for good nutrition!

Any patient undergoing changes in diet and lifestyle, including exercise, should be monitored closely. One would want to check the patient’s cardiovascular and respiratory systems on a regular basis. Also include blood sugar levels for type 2 diabetes and watch mood and behaviour for signs of anxiety, depression, and eating disorders.

Patients undergoing weight loss can change their biochemical parameters (blood lipids, blood sugar, and beyond) quickly. Depending on the medical history, severity of problem, progress, etc., patients must be monitored for relapse or development of a problem that is not anticipated. Weight loss is a great goal; however, some patients do have underlying issues that can make them highly vulnerable to compromise with many changes. It is always best to be alert.

2. Answer: The body retains many sources of energy for exercise.

The most immediate source of energy is two compounds called ATP and CP: these are adenosine triphosphate and creatine phosphate. These energy sources are used by the muscles and are quickly available to them for their immediate needs. ATP is utilized in both anaerobic and aerobic activity and ATPCP can be utilized only in very short bursts of less those 10 seconds of anaerobic activity.

The body utilizes glucose, fatty acids, and protein to produce ATP for energy.

Glucose: Glucose does provide for immediate energy when stored as glycogen. About 2000 kcalories are stored as energy for the muscles, and the more the athlete is conditioned, the more efficiently that athlete can utilize that glycogen, allowing the athlete to utilize the glycogen over a longer period of time. This is a preferable situation because glycogen can be utilized quickly, as opposed to fatty acids that require an extensive period for breakdown prior to utilization. Energy from glycogen provides approximately 20 minutes of performance. Both anaerobic and aerobic activities are supported by glycogen stores.

A highcarbohydrate diet provides more energy for the athlete over the short term.

Fatty acids: Epinephrine signals the fat cells to break down fat for use in physical activity. Once glycogen is utilized or when performance is at 60 percent or less than VO2 max, the body uses fatty acid for energy. These types of athletic events are primarily aerobic events rather than quick, short bursts of intense exercise, and are characterized as the endurance types of sports. Fatty acids are a rich source of energy, depending on the individual, allowing for greater than 70 000 kcal of energy. Clearly fat is a great energy source for distance events, but fatty acids are unavailable for short events that are anaerobic.

Proteins: Amino acids only provide 10 percent of the fuel for activity. Protein’s main functions involve tissue repair, enzymes, and many other important components in the body. Whether athletes require more protein is controversial. After anaerobic events, protein is utilized for muscle development, while in aerobic events, protein is utilized



for energy. Training, intensity, and duration all affect the body’s use of protein. A welltrained athlete can better utilize their glycogen stores and will use their protein intake for tissue repair and muscle development.

3. Answer: Table 157 provides a start for students to start thinking about this question. In the field of sports nutrition, athletes will take anything that they hear will benefit their “game.” The registered dietitian who is not prepared to substantiate his or her point of view will not have credibility in the athletic world. It is always best to work with the athlete on their beliefs without doing harm. Sports drinks are a perfect example. Let students think through this and use the literature to support their cause with a classroom discussion. If some have worked with athletes, let them share their experiences as this is always helpful. In the end and after a good debate, let the class decide together what they think is the best course of action!

4. Answer: For the instructor, the point of the exercise is to demonstrate to students some of the issues that can arise with athletic patients, taking athletic issues from two very different perspectives.

(a) With a “weekend warrior” the RD must be careful to assess all physiological and medical parameters as well as his diet to protect him from injury and more importantly longterm damage from his new regime. First, it is great that he has decided to get active and undertake a more healthful diet; however, when patients decide to undergo some of these drastic changes they may sometimes overdo it in the short term, injure themselves, and then not resume. He should try to adapt changes longterm without any physiologic problems or injury. He also may have an underlying medical problem of which he is unaware that can be exacerbated by the exercise. It is always best when starting a new exercise program after being away from exercise for a while to have a complete medical physical. After that, the best way to do this is to be moderate in his approach, which is where this patient needs to gain some perspective. The RD wants to keep him involved and active and if he is immediately depleted he will not continue. The patient appears to be fairly well educated and articulate; therefore, it would be in the best interests of the RD to approach this patient through a focused nutrition education mode, allowing the patient to help the RD put the new dietary program together. In that manner, the RD is assured that the patient understands the information and he takes ownership of the process.The RD would do well to help the patient change his regime to a more moderate protein diet, such as a 25–35 percent protein diet. In that manner, it is still somewhat high in protein but not as high. A carbohydrate level of 55 percent to allow for complex carbohydrates with fruits and vegetables should be suggested. This adds variety and flavour to the diet. The last is about 10 percent fat, which is needed for many steroid hormones, skin, and the cellular membranes. This diet will provide for all necessary vitamins and minerals. Because this is an endurance event, he can increase his fatty acid intake up to 20 percent of his diet by decreasing his protein intake to 25 percent and adjust the rest of his diet accordingly. For the purposes of weight loss, he may prefer the diet to stay at the

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former level for the time being and adjust the fat percentage upward after he has lost some of his weight.Given the patient is 9 kilograms (20 pounds) overweight, the RD would set a goal of a 1/2–1 kilogram (1–2 pounds) per week weight loss, which can be accomplished by his running regime and diet. It would be important to have some information on the caloric and nutrient content of his previous baseline diet. A goal of removing 500 kcal a day from a combination of diet and increased exercise usually results in a 1/2 kilogram (1 pound) per week weight loss, a very reasonable plan for this patient. His exercise in addition to replacing empty calories with nutrientdense food choices should help to make this an easy goal to reach.It is best to encourage this athlete to consume a multivitamin rather than all the different supplements, at random. Given that these supplements will not enhance performance, this individual can benefit more from a multivitamin supplement, given the diet, rather than taking supplements that have no proven benefit. It is also a better balance for the nutrients overall in the body. To help influence this patient toward this direction, the RD might discuss the benefits of gaining vitamins and minerals through the foods one eats rather than in supplement form because of the variety of factors that influence their uptake and use in the body. However, if the patient insists on taking these supplements, no harm will come from their use, and the RD can thus remain flexible with patients. This flexibility increases trust between the patient and nutrition professional.The use of protein shakes, etc. should be balanced into the overall diet to establish the protein level at no more than 35 percent of the overall diet. Alternatives to these betweenmeal snacks are fruits, dried fruits, plain popcorn, cheese and crackers, etc. The RD can work with the patient to establish a long list of snack foods that are quick to make or can be purchased in order to increase the variety of foods in this patient’s diet and avoid an excessive amount of protein.From this case, it is unclear whether the patient is warming up and cooling down or doing any weight training as well. The RD should ask about these processes and remind the patient that all of these areas are quite important to injury prevention, thus staying on task with his goals. As a sports nutritionist, the RD may work with trainers or be one; therefore, a suggestion to see a trainer at least initially and occasionally during work toward the patient’s goal would be helpful to ensure he stays on task and avoids any major injuries or problems.

(b) This worldclass skater is under constant medical and training care. Therefore, we know that she has been assessed medically. In general, most of these athletes have an athletic trainer who provides some nutrition information. At times there may be an RD. Her diet is too high in protein, so she needs to increase her fat intake to 10 percent and increase her carbohydrate intake to 65 percent. At her age, she is especially in need of the fat for steroid production as well as cellular membranes, etc. Given that she consumes more of a vegetarian diet, I would also suggest that she take a multivitamin with iron to ensure that she is receiving all her necessary vitamins and minerals.



Overall, it would be important to work with the skater and her mother (perhaps separately and then together) on some cycle menus and snack ideas. Given the age and energy expenditure of this skater, her energy requirements are very high. Her estimated energy expenditure is 4549.22 on a daily basis. To consume this many calories can be difficult and with everyone watching the skater, it is important for the mother, coach, and skater to understand her needs and to work with each other to plan healthful food choices that can be available and also made quickly. Worldclass skaters train early in the morning, often, and travel frequently. Therefore, they will be eating many meals on the run and eating out. Helping her and her mom to put together a sorted selection of handy snacks that she can grab quickly will be important. It will also be important to help her select healthy meals at restaurants and learn to order off a menu that does not appear to have anything that she could eat. The more the RD can empower the skater, the more the RD will gain trust with the skater. Yet the RD will also have to work closely with mom and the coach and gain trust equally from them. However, it is the skater that is often left powerless and in this age period it will be especially important for the RD to assist the skater in making her own food choice decisions and learning about the importance of nutrition for her body and the work it needs to do. Once some trust is built between the skater and the RD, the RD can approach the issue of supplements, ergogenic aids, etc. While this may have been approached before, if nothing was gained from the conversation, when trust is built, more pertinent information may be gleaned. The skater will not take anything that will compromise her ability to compete but will take anything that is thought to enhance her performance. Assess all supplements thoroughly and decide if any are causing harm to the patient. If not, it is best to let the supplements go and the skater continue to take them. It is important to be flexible with the athlete and understand that even if the literature indicates that there is no benefit to a particular supplement, in the mind of an athlete, it benefits them! The weight of this skater is borderline low for her height; i.e., she is on the lower end of normal for her height. In athletic events that are judged, one will find much attention paid to weight; therefore, given that she is still within normal limits, the RD should pay close attention to making her diet as nutrientdense as possible and as noted, increasing the fatty acid and carbohydrate intakes. She does appear to be missing her menstrual cycle considering that she is Tanner stage 5. An increase in fatty acid intake to 10 percent or adjusted up to 15 percent for a period of time may assist in helping her body to begin menstruation. At that time it will be particularly important to include iron as a supplement if she continues to maintain a vegetarian diet.Most of all, while this particular skater appears to enjoy what she is doing, this sport can become very stressful and many skaters become disillusioned early in their careers. Remind her to have fun with her skating and with what she eats. A good diet includes a variety of foods so that boredom does not set in while still nourishing one’s body to perform.

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5. Answer: Aerobic physical activity is basically cardiovascular fitness training. It is the type of activity that allows an individual to move all body parts and work the cardiovascular and respiratory systems as well as the muscular and skeletal systems for a positive influence on health status.

Moderateintensity physical activity allows the individual to be engaged in a sport with an increase in heart rate and respirations but not to the point where the individual cannot carry on a conversation. Your textbook points out that moderate intensity would be jogging or walking fast at 5–7 kilometres (3–4 miles) in an hour.

Vigorousintensity physical activity, in contrast, increases the heart rate and respirations significantly so that the individual is unable to carry on a conversation with a colleague. A run beyond 7 kilometres (4.5 miles) in an hour would be a vigorousintensity activity for many individuals.

The overload principle indicates that an individual can improve their abilities in a sport by increasing their frequency of participating in that activity, increasing the intensity of the activity, and increasing the duration of their participation. Coaches will use all three of these factors to improve the performance of an athlete. Over time, use of the overload principle will take a moderateintensity activity for one individual and make it a lowintensity activity for that same individual. Therefore, the person would need to increase the intensity of exercise to achieve moderate or vigorous intensities and further improve cardiorespiratory endurance.

Worksheet Answer KeyWorksheet 151: Cardiorespiratory Endurance Calculation1. MHR = 220 – 15 = 205, THRR: 205 × 0.6 = 123 and 205 × 0.85 = 174.25 2. MHR = 220 – 22 = 198, THRR: 198 × 0.6 = 118.8 and 198 × 0.85 = 168.33. MHR = 220 – 12 = 208, THRR: 208 × 0.6 = 124.8 and 208 × 0.85 = 176.84. MHR = 220 – 50 = 170, THRR: 170 × 0.6 = 102 and 170 × 0.85 = 144.55. MHR = 220 – 80 = 140, THRR: 140 × 0.6 = 84 and 140 × 0.85 = 1196. MHR = 220 – 30 = 190, THRR: 190 × 0.6 = 114 and 190 × 0.85 = 161.57. MHR = 220 – 18 = 202, THRR: 202 × 0.6 = 121.2 and 202 × 0.85 = 171.78. MHR = 220 – 45 = 175, THRR: 175 × 0.6 = 105 and 175 × 0.85 = 148.759. MHR = 220 – 33 = 187, THRR: 187 × 0.6 = 112.2 and 187 × 0.85 = 158.9510. MHR = 220 – 65 = 155, THRR: 155 × 0.6 = 93 and 155 × 0.85 = 131.75

Worksheet 152: Chapter 15 Crossword Puzzle1. hypothermia

2. hyperthermia

3. stroke volume

4A. hyponatremia

4D. heat stroke

5. cardiac output

6. amenorrhea

7. epinephrine

8. exercise

9. sports anemia

Worksheet 153: Physical Activity SelfEvaluationAnswers will vary.

Worksheet 154: Fitness Review (Internet Exercise)1. False 3. True 5. False 7. True



2. b 4. False

6. False

8. True

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WO R K S H E E T AC T I V I T I E S

Worksheet 151: Cardiorespiratory Endurance Calculations

For each of the individuals below calculate the Maximum Heart Rate (MHR) and the Target Heart Rate Range (THRR).

Individual Maximum Heart Rate Target Heart Rate Range

15 year old

22 year old

12 year old

50 year old

80 year old

30 year old

18 year old

45 year old

33 year old

65 year old

Formulas*: MHR = 220 – Age THRR = MHR × 60% to MHR × 85% or MHR × 0.6 to MHR × 0.85



* As one ages, the MHR decreases and the range between THRR narrows.

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Worksheet 152: Chapter 15 Crossword Puzzle

1 2

3

4

5 6

7

8

9

Across Down

1. A belownormal body temperature4. A decreased concentration of sodium in

the blood5. The volume of blood discharged by the

heart each minute (stroke volume × heart rate)

7. One of the stress hormones that is secreted whenever emergency action is called for

9. A transient condition of low hemoglobin in the blood, associated with early stages of sports training or other strenuous activity

2. An abovenormal body temperature3. The amount of oxygenated blood the

heart ejects toward the tissues at each beat4. The dangerous accumulation of body heat

with accompanying loss of body fluid6. The absence of or cessation of

menstruation8. Planned, structured, and repetitive bodily

movement that promotes or maintains physical fitness



Worksheet 153: Physical Activity SelfEvaluation

Fitness depends on a certain minimum amount of physical activity. Ideally, the quantity and quality of the physical activity you select will improve your cardiorespiratory endurance, body composition, strength, and flexibility. Examine your activity choices by keeping an activity diary for one week. For each physical activity, be sure to record the type of activity, the level of intensity, and the duration. In addition, record the times and places of beverage consumption and the types and amounts of beverages consumed. Now compare the choices you made in your oneweek activity diary to the guidelines for physical fitness.

1. How often were you engaged in aerobic activity to improve cardiorespiratory endurance? Was the intensity of aerobic activity between 55 and 90 percent of your maximum heart rate? Did the duration for each session last at least 20 minutes?

2. How often did you participate in resistance activities to develop strength? Was the intensity enough to enhance muscle strength and improve body composition? Did you perform 8 to 10 different exercises, repeating each one 8 to 12 times?

3. How often did you stretch to improve your flexibility? Was the intensity enough to develop and maintain a full range of motion? Did you hold each stretch 10 to 30 seconds and repeat each stretch at least four times?

4. Do you drink plenty of fluids daily, especially water, before, during, and after physical activity?

5. What changes could you make to improve your fitness?

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Worksheet 154: Fitness Review (Internet Exercise)

Go to the following website to answer questions 1–8: http://www.hsph.harvard.edu/nutritionsource/stayingactive/stayingactivefullstory/index.html.

1. The American College of Sports Medicine and the American Heart Association recommend that healthy adults get a minimum of 60 minutes of moderateintensity aerobic activity on five days each week, or get a minimum of 20 minutes of vigorousintensity aerobic activity on five days of the week.a. Trueb. False

2. Which of the following is NOT a benefit of regular physical activity?a. Helps prevent the development of osteoporosis.b. Reduces the incidence of prostrate cancer.c. Decreases the fall risk for older adults.d. Helps to control weight.

3. According to CDC research findings obtained in 2001, with respect to cardiovascular disease, the estimated direct medical cost was nearly $24 billion.a. Trueb. False

4. Any type of physical activity that meets the criteria of the “talk test” without a corresponding increase in heart rate provides a cardiac benefit.a. Trueb. False

5. Research has shown that swimming exercises substantially reduce the chance of developing heart disease, stroke, and diabetes in different populations.a. Trueb. False

6. Thirty minutes of moderateintensity aerobic activity a day is the optimal level that one should seek to achieve.a. Trueb. False

7. The Borg scale can be used to evaluate one’s perception of how hard one is exercising.a. Trueb. False

8. One benefit of strength training is that it increases lean body mass.a. Trueb. False


http://www.hsph.harvard.edu/nutritionsource/staying-active/staying-active-full-story/index.html


Handout 151: I’m in Shape but Why Am I Tired?

Many athletes spend a long time getting into shape. They may train for that 10K run or 20mile bike race. They may learn a lot about their body’s performance for their sport.

After a period of time, they may notice that they are tired and they suddenly cannot train at the same level anymore. Some athletes get frustrated and give up, but what they may need to do to get past this “slump” is to learn about nutrition and how it can enhance performance. The textbook has a lot of suggestions as outlined below.

Causes Symptoms Dietary Suggestions

Dehydration Headache, fatigue, rapid pulse, brightly coloured urine (small amount), reduced athletic performance

• Drink 250–500 mL (1–2 c) 2 hours before the activity

• Drink 125–250 mL (½–1 c) every 15 minutes during the activity

• Drink plenty of liquid after the activity

Anemia Shortness of breath while exercising, fatigue, and feeling cold

• Get plenty of B vitamins, especially folate and vitamin B12

• Get plenty of iron from meat (heme) and vegetable (nonheme) sources

Lack of Carbohydrates

Reduced ability to continue with the athletic activity

• Get plenty of complex carbohydrates from whole grains, breads, and pastas

Lack of Protein Reduced ability for muscles to recover

• Select lowfat sources of protein such as skim milk, fish, lean cuts of meat, soy products, and beans

Contributed by Mary Ellen Clark.

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Handout 152: Developing PerformanceEnhancing Eating Plans

Scene: You are an athletic trainer’s assistant who has been asked to help develop the best meal plans for athletes at your local university. You have three student athletes that you need to give nutrition advice too.

Athlete #1: Brent is a promising baseball player who is training to be a pitcher. Brent is 1.8 metres (6 feet) tall and weighs 68 kilograms (150 pounds). He is 19 years old. He wants to add weight and strength for the baseball season. He does not cook and he does not have a car but he does eat at the campus cafeteria.

Athlete #2: Kelly is a crosscountry runner who is also a vegan. She is 21 years old. She is 1.67 metres (5 feet 6 inches) tall and she weights 56.7 kilograms (125 pounds). She has been noticing that she is very tired after races. She wants to try to eat better to help her improve her endurance. She likes to cook when she can find the time.

Athlete #3: Frank is a weight lifter who needs to lose some body fat but wants to maintain his strength. He is 20 years old. He is 1.72 metres (5 feet 8 inches) tall and he weighs 102 kilograms (225 pounds). He would like to have more energy during his weight lifting events. Frank has a kitchen and he loves to eat lots of pasta.

Assignment: You have been asked to develop an eating plan for each of these athletes that incorporates adequacy, balance, moderation, and variety. You may have to adjust the calorie counts based on the individual athlete’s needs.

Using the information that you have learned in Chapter 10 of the textbook to help you, design a typical daily eating plan for each of these athletes.

Needs: Brent needs to gain lean body mass (muscle) and increase his calorie counts. You can determine what his basal metabolic rate and activity level are to determine his daily calorie needs. You need to increase his number of calories each day. Be careful about the types of foods that you select to help Brent gain weight.

Kelly does not eat any animal products, so consider how she can get enough protein, fat, and essential vitamins in her diet. She needs to get plenty of water, iron, and carbohydrates in her diet. This could help with her fatigue.

Frank needs to lose body fat but maintain or gain muscle mass. Consider how he can reduce his total calories while maintaining his energy level. Again, you will need to determine what his basal metabolic rate and activity level are to determine his daily calorie needs.

Your diet plan for each athlete should include: • Athlete’s Name• Calories Used Per Day• Calories Needed Per Day• Meal Plan (Typical 1 Day)

Check out your diet plan by using a diet analysis program such as Diet Analysis Plus. You can enter your athlete’s profile (age, sex, height, and weight) and obtain daily goals based on the Dietary Reference Intakes (DRI). You can enter your suggested meal plan to see if it meets the DRI recommendations for your athlete.

Contributed by Mary Ellen Clark.


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