CH-1-2 Introduction to Sports Nutrition – Nutrition for Sport and Exercise : Chapter Notes

This Document Contains Chapters 1 to 2 Chapter 1: Introduction to Sports Nutrition Overarching Concepts 1. Type, intensity, and duration of training are the driving forces in determining energy and nutrient needs. 2. Most recreational athletes do not engage in a level of training that requires a diet different from that recommended for good health to the general population. 3. Athletes need a comprehensive training plan and a matching comprehensive nutrition plan. 4. Supplementation should be considered as part of the comprehensive nutrition plan. 5. Scientific recommendations are only as strong as the studies on which they are based. 6. Food is for fueling exercise and training as well as for enjoyment. 7. Credentialing protects consumers and practitioners and it is important to know and respect professional boundaries. Learning Objectives LO 1.1 Explain the need for an integrated training and nutrition plan. LO 1.2 Explain basic nutrition principles and how they might be modified to meet the needs of athletes. LO 1.3 List sports nutrition goals. LO 1.4 Outline the basic issues related to dietary supplements and ergogenic aids, such as legality, ethics, purity, safety, and effectiveness. LO 1.5 Distinguish between types of research studies, weak and strong research designs, and correlation and causation. LO 1.6 Compare and contrast the academic training and experience necessary to obtain various exercise and nutrition certifications. Chapter Outline I. Introduction A. Pre-test assessment B. Introductory concepts 1. Sports nutrition is a blend of nutrition and exercise physiology 2. Science-based but there is an art to application II. 1.1 Training, nutrition, and the athlete • Sports nutrition requires an understanding of the physiological challenges of training and competition and the scientific and applied principles of nutrition. • The physical demands of activity, exercise, and sport can vary dramatically between athletes and for individual athletes over a given time period. • Training and nutrition go hand in hand. • An organized training plan that takes into account specific goals and incorporates basic principles of training is critical for excellent performance. • Athletes need a nutrition plan that complements the physical demands of training and performance and supports good health. A. Sports nutrition is a blend of exercise physiology and nutrition. B. The term athlete is very broad and inclusive. 1. Differences between elite, well-trained, and recreational athletes C. Physical activity, exercise, and sport differ from each other 1. Differences between physical activity, exercise, and sport 2. Aerobic and anaerobic exercise 3. Endurance and strength athletes D. Training and nutrition go hand in hand. 1. “Everyone is an athlete” 2. Training is key to improving performance 3. Nutrition supports training and good health 4. Dietary intake needs daily attention but an athlete’s diet must be flexible E. Nutrition supports training and performance. 1. Main goal for athletes is to improve performance 2. General training goals a. Improve performance b. Improve fitness c. Avoid injury and overtraining d. “Peak” at appropriate times 3. General (long-term) sports nutrition goals a. Adequate energy intake to fuel training b. Adequate carbohydrate intake to replenish depleted glycogen stores c. Adequate protein intake for growth and repair of muscle d. Adequate overall diet for good health, particularly the immune system e. Adequate hydration for proper thermoregulation 4. Specific (short-term) sports nutrition goals a. Consumption of food and beverages to delay fatigue b. Consumption of fluid to minimize dehydration and hypohydration c. Application of specific dietary strategies such as carbohydrate loading d. Intake of nutrients that support recovery F. It is important to understand basic training principles. 1. The principle of progressive overload 2. The principle of individuality 3. The principle of specificity 4. The principle of hard/easy 5. The principle of periodization a. Macrocycle b. Mesocycle c. Microcycle 6. The principle of disuse G. In addition to a training plan, an athlete needs a nutrition plan. 1. Nutrition periodization: Nutrition plan to support training and body composition goals Question for discussion: What would be some specific training goals of a collegiate-level soccer player? III. 1.2 Basic nutrition standards and guidelines • The Food Pyramid for Athletes is an excellent meal-planning tool for athletes. • The Dietary Guidelines, MyPlate, and the Nutrition Facts label are tools that can be used to develop a nutritionally sound diet plan. • The Dietary Reference Intakes (DRI) is a standard used to assess and plan diets. A. The Dietary References Intakes (DRI) is a standard used to assess nutrient intake. 1. Standard used to assess and plan diets 2. Applicable to athletes with a few exceptions (e.g., energy, water) B. The Dietary Guidelines for Americans provide basic dietary and exercise advice. 1. General diet and exercise advice 2. Applicable to athletes with a few exceptions (e.g., sodium) 3. Basic recommendations can be modified to meet the athlete’s needs C. MyPlate is a tool that can be used to create a nutritious diet. D. A food pyramid has been developed for athletes. E. There are several other meal-planning tools available. 1. Food Exchange System 2. Carbohydrate counting F. The Nutrition Facts label provides specific nutrition information. Question for discussion: Are the various meal-planning tools substantially different from each other? IV. 1.3 Basic sports nutrition guidelines – to support training, performance and health • Sports nutrition recommendations include guidelines for energy, nutrient and fluid intake, and nutrient timing. • It is important to understand the specifics of the athlete’s sport and position played when making nutrition recommendations. A. Overview of key sports nutrition recommendations 1. Adequate energy intake a. Energy intake needed to maintain energy balance b. Adjustments to energy intake (e.g. change body composition) 2. Adequate carbohydrate intake a. 3-12 g/kg body weight daily b. Proper timing of intake c. Use of glycemic index 3. Adequate protein intake a. 1.2-1.7 g/kg body weight daily b. Proper timing of intake 4. Adequate fat intake a. Fat intake is typically 20-35 percent of total calories b. Proper timing of intake 5. Vitamin and mineral intake a. Meet the DRI b. Emphasis on nutrient-dense foods 6. Fluid intake a. Match fluid intake with fluid loss 7. Food and fluid intake prior to exercise 8. Food and fluid intake during exercise 9. Food and fluid intake after exercise 10. Other a. Appropriate body composition b. Healthful weight-loss practices c. Avoidance of disordered eating or eating disorders d. Flexible eating plan B. The demands of an athlete's sport must be carefully considered. Question for discussion: Why might a lineman, linebacker, and wide receiver on the same football team have very different nutrition needs? V. 1.4 Dietary supplements and ergogenic aids • In the United States, dietary supplements are not required to be proven safe or effective before being sold. • The majority of athletes at all levels use at least one dietary supplement. • In many cases, athletes use a random approach to choosing dietary supplements. • Some supplements may contain banned substances. • Many dietary supplements are safe, but some are not. • Some supplements are contaminated, particularly weight loss and muscle-building supplements. • Only a handful of supplements have been proven to be effective. A. In the United States, the law that governs dietary supplements is the Dietary Supplement Health and Education Act (DSHEA). a. Terminology b. Areas covered by the law c. Areas not covered by the law d. Potency and purity issues B. Many products fall under the umbrella known as dietary supplements. C. Dietary supplement use among athletes is high. D. Athletes consume supplements for many reasons. E. Knowledge of a supplement’s legality, safety, purity, and effectiveness is crucial. 1. Legality of dietary supplements 2. Safety of dietary supplements 3. Purity of dietary supplements 4. Effectiveness of dietary supplements 5. Quackery a. Multilevel marketing (MLM) b. Internet resources regarding quackery F. Spotlight on supplements: Evaluating dietary supplements – Process for evaluating dietary supplements 1. Gather information 2. Weigh the information 3. Judge the information 4. Use critical thinking skills to make a decision Question for discussion: What specific things should an athlete consider before choosing to take a dietary supplement? VI. 1.5 Understanding and evaluating scientific evidence • Sports nutrition recommendations should be evidence based. • The strength of any scientific recommendation depends on the quality of the research conducted. • A strong research design is fundamental to obtaining accurate results. • Epidemiological and experimental studies provide different types of data. • Individual research studies are important, but knowledge of the body of literature is necessary to understand a topic. • Much of the information on the Internet about exercise, nutrition, and dietary supplements is inaccurate. A. There are three basic types of research studies. 1. Case studies 2. Epidemiological studies 3. Experimental studies B. The basis of good research is strong research design and methodology. 1. Randomization 2. Use of placebo 3. Blinding 4. Familiarization trial 5. Crossover C. Peer review is an important safeguard in the publication of scientific research. 1. Peer review process 2. Peer-reviewed journals D. Levels of evidence and grades of recommendations put the scientific body of literature in perspective. 1. Grade I (Level A) a. Rich body of data b. Consistent results from large, well-designed studies 2. Grade II (Level B) a. Limited body of data b. Inconsistent results or consistent results from limited number studies 3. Grade III (Level C) a. Limited evidence b. Results from studies with design limitations 4. Grade IV (Level D) a. Consensus opinion b. Based on limited evidence, observations, and clinical experiences 5. Anecdotal evidence E. Conclusions from scientific studies can be misinterpreted. 1. Distinguish between causation and association 2. Understand the importance of replicating results 3. Extrapolate results of scientific research with caution, if at all 4. Interpret results correctly 5. Focus on cumulative results and consensus 6. Recognize the slow evolution of the body of scientific knowledge F. Not only scientists read scientific studies. – Consumer exposure to scientific studies 1. Spotlight on supplements – Using scientific studies as a marketing tool G. Much of the nutrition-, exercise-, and health-related information on the Internet is inaccurate. H. The Internet café – Use of the Internet for finding scientific information about sports nutrition Question for discussion: How would you design a research study to determine the effect of Supplement XYZ on vertical jump height? VII. 1.6 Exercise and nutrition credentials and certifications • Certifications vary widely in their requirements. • Many exercise- and nutrition-related certifications do not require a bachelor’s degree. • Practitioners must recognize the limits of their knowledge, training, and expertise or athletes can be harmed. A. There are many types of practitioners in the area of exercise science. B. There are many types of practitioners in the area of nutrition. C. Scope of practice helps establish professional boundaries. 1. Establishing professional boundaries 2. Exercise-related certifications 3. Nutrition-related certifications 4. Use of public domain documents Question for discussion: What’s the difference between a sports dietitian, a sports nutritionist, and a nutritionist who works with athletes? VIII. Summary and review A. Chapter summary B. Post-test assessment C. Review questions D. References Supplementary Teaching Materials and Classroom Activities Note: The text chapter includes an application exercise featuring an ex-collegiate tennis player who returns to competitive play (p. 15). Activity 1-1 The first day of class is always exciting. Teachers and students alike are renewed after some time away from the classroom and there is excitement in the air. One of the challenges of teaching is to capture that first day enthusiasm and maintain it throughout the semester. While much of the first day of class is devoted to the details of enrollment, expectations, and course syllabi, there is usually enough time to begin to get the know the students and the sports-related experiences they bring to the classroom. Here are some examples of first-day classroom activities that may be useful in efforts to discover each student’s connection to sports, training, and nutrition. Take an inventory of the many sports that may be represented in class, either by the students’ participation and/or interest. Are there athletes who are currently training or competing? How many have trained or competed in high school and in what sports? What activity do students do for their main type of exercise? Not all students can be drawn into the discussion but many are willing to “represent” their sport or exercise activity when questions arise during the semester. Make a list of questions that students have about sports nutrition. What have they “heard”? Which topics do they have the most interest in? What topics do they expect to learn about? What kinds of sports nutrition questions do they expect to answer as a professional? Activity 1-2 Most students have a favorite sport and know a lot about it. Have each student choose a sport and briefly sketch out a training plan using the three general training periods—preparation, competition, and transition (“off-season”). The plan can be referred to throughout the term to help illustrate how training drives the need for energy and nutrients and how realistic body composition goals are established. This activity may be done individually or in groups. Sharing the various training plans can help students increase knowledge of sports they are unfamiliar with. If the sports nutrition course is offered during the same term as a related course such as sports performance, consider coordinating projects so that students prepare training and nutrition periodization plans concurrently. Activity 1-3 Have students become familiar with research that appears in peer-reviewed journals (some examples are given in Figure 1.15 on page 26) by summarizing a journal article. This assignment may be completed in class if copies are made of an article or as an outside-of-class assignment by having students locate an article. Journal Article Summary Assignment The purpose of this assignment is to examine original research papers in peer-reviewed exercise physiology or sports nutrition journals and to write a concise summary of the important aspects of the article. The assignment consists of two parts: Annotated citation - consists of correct citation in APA (American Psychological Association) format, followed by a concise description of the major findings and important aspects of the study. The article should be an experimental research study (not a case study, clinical study, or review article). If you have any doubts about the type of article or journal you have selected, check with the instructor. The annotation should be a concise summary of the major findings and important aspects of the study. It should be approximately 1-3 paragraphs in length, and should include the purpose of the study, important details of the study design and methods, and a summary of the results, conclusions, and practical application(s) or significance of the study. The annotation is written in your own words! Do not copy the purpose statement or concluding statements of the authors from the article. Journal article copy - make a complete copy of your article including references to turn in with your review. Crossword Puzzle Answer Key 1. macronutrient 2. fatigue 3. electrolyte 4. overload 5. energy 6. nutrient dense 7. placebo 8. training 9. mortality 10. correlation 11. A: atrophy; D: aerobic 12. fiber 13. intensity 14. anaerobic Word Find Puzzle Answer Key • 6 basic training principles: progressive overload, individuality, specificity, hard/easy, periodization, disuse • 4 types of reference values that make up the DRI: RDA, AI, EAR, UL • 6 minerals Americans tend to under-consume: potassium, calcium, iron • 2 supplements that are considered safe and effective for improving athletic performance: caffeine, creatine • 3 categories of research studies: case, epidemiological, experimental • 4 characteristics of a strong research protocol: randomized, double-blind, placebo-controlled, crossover T E R A N D O M I Z E D O U S S T I I E P I D E M I O L O G I C A L I G H N P R O G R E S S I V E O V E R L O A D O U S L Y E E T U Y H R I M B E R O I T S U R T I N C A S E G D H T E U O V A K L S I W I H O A E E V A E B R I I S G A I C N T S T E T H E P L R I C D S M N O I T A Z I D O I R E P K A C U I U R T F H E E E R T O B K I A C A A U I I T I I R S H A A L R D F I O F L M C I N C T C H E H I T H O R N T F I P L A C E B O C O N T R O L L E D E T T A H E P W H I D R L W I N D I S I Y E C R O S S O V E R W E E A R M O N S I O V T E K L U M N O E H S R I A E H I R O N E H E X P E R I M E N T A L T Chapter 1 Crossword Puzzle Across Down 4. An exercise stimulus that is of sufficient magnitude to cause enough stress to warrant long-term changes by the body. 6. A food containing a relatively high amount of nutrients compared to the caloric content. 8. A planned program of exercise with the goal of improving or maintaining athletic performance. 10. A relationship between variables. 11. A wasting or decrease in organ or tissue size. 13. The absolute or relative difficulty of physical activity or exercise. 14. Exercise that primarily uses one or both of the energy systems that are not dependent on oxygen. 1. Any essential nutrient needed in large quantities. 2. Decreased capacity to do mental or physical work. 3. A substance in solution that conducts an electrical current. 5. The capacity to do work. 7. An inactive substance. 9. Death; the number of deaths in a population. 11. Exercise that primarily uses oxidative phosphorylation. 12. A component of food that resists digestion. Chapter 1 Word Find Puzzle T E R A N D O M I Z E D O U S S T I I E P I D E M I O L O G I C A L I G H N P R O G R E S S I V E O V E R L O A D O U S L Y E E T U Y H R I M B E R O I T S U R T I N C A S E G D H T E U O V A K L S I W I H O A E E V A E B R I I S G A I C N T S T E T H E P L R I C D S M N O I T A Z I D O I R E P K A C U I U R T F H E E E R T O B K I A C A A U I I T I I R S H A A L R D F I O F L M C I N C T C H E H I T H O R N T F I P L A C E B O C O N T R O L L E D E T T A H E P W H I D R L W I N D I S I Y E C R O S S O V E R W E E A R M O N S I O V T E K L U M N O E H S R I A E H I R O N E H E X P E R I M E N T A L T Instructions: In the grid above, find the following words or phrases, and then write them beside each clue. • 6 basic training principles: • 4 types of reference values that make up the DRI: • 6 minerals Americans tend to under-consume: • 2 supplements that are considered safe and effective for improving athletic performance: • 3 categories of research studies: • 4 characteristics of a strong research protocol: Chapter 2: Defining and Measuring Energy Overarching Concepts 1. The energy contained in food is converted to chemical energy in the body and used immediately or stored for later use. 2. The caloric content of foods can be estimated but the precise amount of energy that food yields in the human body is not known. 3. Energy expenditure can be measured, but not easily. An open-circuit metabolic measurement system found in most exercise physiology labs is a reasonably practical and accurate measurement technique. 4. Resting metabolic rate (RMR) can be measured with reasonable accuracy. Most of the influences on RMR are not under voluntary control or are subtle. Increasing skeletal muscle via resistance exercise is a practical and effective way to increase RMR. 5. Caloric intake, RMR, thermic effect of food (TEF), and energy expenditure through physical activity can be reasonably estimated. These estimates can be used to determine “energy in” and “energy out” and to predict whether energy balance or imbalance is likely. Learning Objectives LO 2.1 Define and explain bioenergetics (using in your definition ATP, calorie, kilocalorie, and other energy-related terms), explain the concepts of energy transfer and utilization in the body, and identify the primary source of energy in the body and how it is used by skeletal muscle during exercise. LO 2.2 Explain how the energy content of food and energy expenditure are measured directly and indirectly and how the most accurate estimates can be made. LO 2.3 List and explain the components of the energy balance equation, the factors that influence metabolic rate, how metabolic rate is measured or predicted, and the impact of physical activity on energy expenditure. Chapter Outline I. Introduction A. Pre-test assessment B. Introductory concepts 1. Energy is a huge topic 2. Understanding how to define and measure energy is a good starting point 3. Energy balance is simply defined as “Energy in = Energy out” II. 2.1 Energy and energy concepts • Energy contained in food is transferred to other forms that can be used in the body. • High-energy phosphates such as adenosine triphosphate (ATP) are chemicals that can store and release energy. • ATP is the common energy source used by all cells in the body. • Energy for muscle contraction is provided directly by ATP. • Three major energy systems are used to replace ATP that is used for muscle contraction. A. Energy is the ability to perform work. 1. Definition: Energy is the ability to do work 2. Energy exists in different forms a. Chemical work (e.g. stored carbohydrate or fat for later use) b. Electrical work (e.g. transmission of neurological impulses) c. Mechanical work (e.g. force production by skeletal muscle) d. Transportation work (delivery of oxygen and nutrients to tissues) 3. First Law of Thermodynamics a. “Within in a closed system, energy is neither created or destroyed” b. Humans are relatively inefficient “machines” 4. Storing and releasing energy a. Potential energy 1. Stored energy (e.g. water behind a dam, muscle glycogen) b. Kinetic energy 1. Energy of motion (e.g. release of water from a dam, use of glycogen during exercise) c. Endergonic reactions 1. Processes or reactions that store energy 2. Examples: setting a mousetrap, rephosphorylation of ADP to form ATP d. Exergonic reactions 1. Processes or reactions that release energy 2. Examples: springing of a mousetrap, release of energy when ATP is hydrolyzed B. High-energy phosphate compounds store and release energy. 1. Adenosine triphosphate (ATP) a. Structure b. Breakdown of ATP and the release of energy c. Spotlight on... The Role of Enzymes 2. Use of ATP by muscle a. Attachment (crossbridges) 1. Energy from ATP puts myosin heads in an energized state b. Force production (contraction) 1. Power stroke 2. Sliding Filament Theory c. Detachment (relaxation) 1. Reloading of ATP on the myosin head d. ATP concentration in muscle 1. Does not drop more than 20-30% 2. Muscle fatigues and protects against ATP depletion 3. Resynthesis of ATP a. ADP is rephosphorylated to form ATP b. Three energy systems to replenish ATP 1. Creatine phosphate 2. Anaerobic glycolysis 3. Oxidative phosphorylation Question for discussion: What happens when ATP levels in muscle decrease too much? III. 2.2 Measuring Energy • The SI unit of measure for energy is the Joule (J). • Because the amount of energy expressed by a Joule is small, the kilojoule (kJ) is commonly used when expressing the energy contained in food. In countries such as the United States, energy in food is expressed as kilocalories (kcal), with 1 kcal being equal to 4.2 kJ. • The energy content of foods is determined by direct calorimetry in which the heat energy released is measured when they are burned in a bomb calorimeter. • The energy content of carbohydrates, fats, proteins, and alcohol is expressed as the number of kilocalories per gram of that food, and is approximately 4, 9, 4, and 7 kcal/g, respectively. • Energy expenditure by individuals can be measured by direct calorimetry in room-size calorimeters or by indirect calorimetry by measuring the amount of oxygen consumed and carbon dioxide produced. A. Introductory concepts 1. International System of Units (SI units) 2. Joule (J) 3. Correct terminology: Calorie (C) or kilocalorie (kcal) or kilojoule (kJ) 4. Commonly used in the U.S.: calorie (cal) 5. To convert kJ to kcal: divide kJ by 4.2 kcal/kJ a. 8,400 kJ ÷ 4.2 kcal/kJ = 2,000 kcal B. The energy content of food is measured by calorimetry. 1. Direct calorimetry a. Bomb calorimeter measures temperature change when food is burned 2. Caloric content of carbohydrates, fats, proteins, and alcohol a. Bomb calorimeter vs. human calorimeter 1. Humans cannot completely burn protein 2. Carbohydrates a. 4.2 kcal/g (rounded to 4 kcal/g) 3. Proteins a. 5.7 kcal/g in bomb calorimeter b. Nitrogen cannot be oxidized by humans c. 4.2 kcal/g (rounded to 4 kcal/g) 4. Fats a. 9.4 kcal/g (rounded to 9 kcal/g) 5. Alcohol a. 7.0 kcal/g (slightly less if liver cells are damaged) 6. “Rule of thumb” calculations a. 10 g carbohydrate or protein = 40 kcal b. 10 g fat = 90 kcal c. 10 g alcohol (ethanol) = 70 kcal 7. All caloric values for humans are only estimates a. Strict “calorie counting” not recommended C. The amount of energy expended can be measured directly or indirectly. 1. Direct calorimetry a. Measures temperature change by measuring heat associated with energy expenditure b. Whole-room calorimeters are used for research 2. Indirect calorimetry a. Measures relationship between oxygen consumption, carbon dioxide production, and energy expenditure b. Whole-room calorimeters are used for research c. Open-circuit metabolic measurement systems 1. 1 liter (1 L) oxygen consumed = approximately 5 kcal of energy expenditure 2. Figure includes energy used for resting metabolism 3. Resting metabolic rate (RMR) can be calculated separately 4. Used in exercise physiology labs (AND in specialized practice; e.g., exercise physiology professionals who take measurements in the athletes’ usual work environments) d. Portable systems 1. Measuring RMR a. Guidelines for more accurate measurement 1. Fast for at least 5 hr 2. Abstain from alcohol or nicotine for at least 2 hr 3. Abstain from caffeine for at least 4 hr 4. Abstain from vigorous resistance exercise for at least 14 hr 5. Abstain from moderate exercise for at least 2 hr b. Used in nonresearch settings such as health clubs 2. Estimating energy expenditure a. Used for research e. Long-term measurements 1. Doubly Labeled Water (DLW) a. Used for research f. Accuracy - Focus on Research highlight Questions for discussion: (1) What type of energy expenditure measurement device would be best suited to obtaining accurate measurements while an athlete is performing in his or her sport (for example, playing soccer)? (2) What is meant by the statement, “Food = fuel = exercise?” IV. 2.3 Concepts of energy balance • Energy intake is determined by recording and analyzing food intake, which must be done accurately for the results to be meaningful. • The major influences on energy expenditure are resting metabolism and physical activity. • Resting metabolism accounts for approximately 70 percent of a sedentary person’s daily energy expenditure and can be influenced by a variety of factors. The two major factors under voluntary control are avoiding a starvation diet and building and maintaining skeletal muscle mass. • Resting metabolic rate and total energy expenditure can be measured by direct or indirect calorimetry, and/or estimated by using prediction equations. • The factor contributing to daily energy expenditure that can be influenced the most by voluntary behavior is physical activity. • Energy balance refers to the relationship between the amount of energy consumed and the amount of energy expended, usually on a daily (24-hour) basis. • Athletes should first consider their energy expenditure and then plan their energy intake to meet the demands and goals of their training and competition. A. “Energy in = energy out” B. Energy intake is estimated by analyzing daily food and beverage consumption. 1. Self-reported food intake a. Accurate recording is needed b. Portion sizes must be estimated correctly c. Food intake is typically underestimated by 10-20% d. Errors in data entry can occur C. Components of energy expenditure can be estimated by different methods. 1. Total Energy Expenditure (TEE) a. Resting metabolism b. Thermic effect of food c. Physical activity 2. Basal and resting metabolism a. The major component of TDEE b. Basal metabolic rate (BMR) 1. Minimal amount of energy needed to sustain life 2. Measured under defined laboratory conditions 3. Used for research c. Resting metabolic rate (RMR) 1. Estimate of BMR 2. Measured under less strict conditions 3. RMR is typically 10% greater than BMR 4. Used for practical purposes 5. Approximately 70% of TEE is attributed to RMR 6. Factors affecting RMR a. Not under voluntary control 1. Gender a. RMR slightly less for females 2. Genetics a. RMR tends to be similar among family members 3. Age a. RMR decreases with age b. Approximately 1-2% decrease per decade 4. Height a. Larger body surface area = higher RMR 5. Thyroid hormones b. Substantial influence, under some voluntary control 1. Starvation a. Decreases RMR by 20% or more b. Too severe of a caloric restriction impedes weight loss c. RMR does not return to baseline immediately after re-feeding 2. Amount of fat-free mass a. Increases RMR because fat-free tissue is more metabolically active than fat b. Resistance exercise can increase fat-free tissue c. Subtle influence, under some voluntary control 1. Exercise a. Study results are inconsistent b. Consensus opinion: RMR increased for short period of time (10-90 minutes) 2. Environmental temperature/altitude a. Increased RMR if colder or higher altitude b. Increase is temporary 3. Caffeine a. RMR increased for short period of time (approximately 2-3 hrs) 3. Estimating resting metabolic rate (RMR) a. For practical reasons, typically estimated via prediction equations b. Prediction equations are only estimates 1. Mifflin-St. Jeor is reasonably accurate to use with nonobese and obese healthy Caucasians (excellent step-by-step instructions in Figure 2.23) 2. Cunningham equation better accounts for fat-free mass and may be more accurate to use with athletes 3. A very simple formula is used when no other method is available 4. Thermic Effect of Food (TEF) a. Energy required for the digestion and absorption of food b. Estimated to be 10% of total caloric intake for the day c. Proteins increase TEF more than carbohydrates d. Effect of TEF on RMR is very small 5. Physical activity a. Under substantial voluntary control b. Can be a substantial influence on TEE 6. Estimating daily energy expenditure through physical activity a. Self-reported activity logs are the most practical method 7. Estimating energy expended by a single physical activity a. Use of computer program is easy and practical b. Hand calculations are also possible c. Estimates typically include RMR as well as energy expended from the activity D. Estimated Energy Requirement is a daily balance of energy intake and expenditure. 1. Estimated energy requirement (EER) 2. Use of computer program is easy and practical 3. A “ballpark” figure is used when no other method is available a. “Ballpark” figures based on gender and physical activity level 1. Range: 30 kcal to 58 kcal/kg/day 2. Estimates derived from surveys and clinical observations Question for discussion: What are the advantages and disadvantages of the various methods for estimating energy expenditure for physical activities such as walking or jogging? V. Summary and review A. Chapter summary B. Post-test assessment C. Review questions D. References Supplementary Teaching Materials and Classroom Activities Note: The text chapter includes an application exercise requiring determination of RMR and exercise-related energy expenditure (p. 60). Activity 2-1 Arrange for students to observe or participate in indirect calorimetry of energy expenditure in an on-campus exercise physiology laboratory by contacting the lab early in the semester. Most exercise phys labs have an open-circuit metabolic measurement system that can be demonstrated to students. Other indirect calorimetry methods for determining energy expenditure may also be available. Students may be allowed to sign up for such measurements, although a fee may be required. Similarly, a determination of resting metabolic rate (RMR) may be available to students. If demonstrated, have students calculate estimated RMR using the simplified formula (see Figure 2.25 on page 57). When the measurement RMR estimate is available have students compare the two estimates and discuss the magnitude of and reasons for the difference. Activity 2-2 Have students practice energy calculations and conversions. This can be an in-class exercise or an out-of-class assignment. Some sample calculation questions are shown here (answers follow). In-Class Assignment Please show your work on calculations so that if you make a mistake you will be able to see where the mistake was made. 1. On average, male jockeys consume approximately 6769 kJ daily. How many kcal are consumed? 2. Female jockeys consume approximately 1,480 kcal daily. How many kJ are consumed? 3. How many kcal in 1 teaspoon of oil? 4. How many kcal in a 12 oz. Budweiser beer? 5. If a food contains 35 g carbohydrate, 4 g protein, and 14 g fat, how many kcal are there? How many kJ are in this food? 6. Determine your body weight in kg. If you do not wish to use your own weight, calculate the body weight in kg of someone who weights 176 lb. In-Class Assignment Answers 1. On average, male jockeys consume approximately 6769 kJ daily. How many kcal are consumed? 6769 kJ ÷ 4.2 kcal/kJ = 1,612 kcal 2. Female jockeys consume approximately 1,480 kcal daily. How many kJ are consumed? 1,480 kcal × 4.2 kJ/kcal = 6,216 kJ 3. How many kcal in 1 teaspoon of oil? Before performing this calculation students will need to know that 1 teaspoon of oil contains 5 g. Not including this information in the original question makes students think about what information they need to solve this problem. 5 g × 9 kcal/g = 45 kcal 4. How many kcal in a 12 oz. Budweiser beer? Students will need to know that this beer contains 11 g of carbohydrate (CHO) and 14 g of alcohol. 11 g CHO × 4 kcal/g = 44 kcal of CHO 14 g alcohol × 7 kcal/g = 98 kcal of alcohol 44 kcal + 98 kcal = 142 kcal 5. If a food contains 35 g carbohydrate, 4 g protein, and 14 g fat, how many kcal are there? How many kJ are in this food? 35 g CHO × 4 kcal/g = 140 kcal of CHO 4 g protein × 4 kcal/g = 16 kcal of protein 14 g fat × 9 kcal/g = 126 kcal of fat 140 kcal + 16 kcal + 126 kcal = 282 kcal 282 kcal × 4.2 kJ/kcal = 1,184 kJ Ask students to guess what food this might be. (Snickers Bar) 6. Determine your body weight in kg. If you do not wish to use your own weight, calculate the body weight in kg of someone who weights 176 lb. 176 lb ÷ 2.2 lb/kg = 80 kg Activity 2-3 Have students estimate daily energy expenditure. This can be an in-class exercise or an out-of-class assignment. Some sample calculation questions and answers are shown here. In-Class Assignment 1. Estimate your daily energy expenditure using the sedentary activity level figure in Table 2.4 (see page 62). If you do not wish to use your own weight, make the calculation based on someone who weights 142 lb. The estimate is based on 30 kcal/kg for females and 31 kcal/kg for males. 142 lb (64.5 kg) female: 64.5 kg × 30 kcal/kg = 1,935 kcal 142 lb (64.5 kg) male: 64.5 kg × 31 kcal/kg = 2,000 kcal 2. Using Table 2.4, estimate your daily energy expenditure for the three periods—preparation, competition, and transition (“off-season”)—previously outlined when you sketched a general training plan (see chapter 1 activities). 142 lb (64.5 kg) male: Preparation (training 3-5 days/week): 38 kcal/kg Competition (training 5 days/week): 41 kcal/kg Transition (sedentary): 31 kcal/kg 64.5 kg × 38 kcal/kg = 2,451 kcal 64.5 kg × 41 kcal/kg = 2,644 kcal 64.5 kg × 31 kcal/kg = 1,999 kcal For most athletes, energy expenditure is lowest in the transition period (active recovery or “off season”). Outside of Class Assignment Record all of your activities for one or more days. Using the Diet Analysis+ computer program that accompanies this textbook, enter in all activities for each 24-hour period. These activities will include activities of daily living such as sleeping, sitting, and working at a desk job as well as specific physical activities. You must enter in activities for a total of 24 hours. An estimate of 24-hour energy expenditure can be viewed on the screen or printed. If you are recording more than one day’s activities, it is recommended that you choose at least one day that you consider to be active and one day that is relatively sedentary. If you are in training, record current activity, but you may also want to estimate energy expenditure in another mesocycle for comparison purposes. After you have an estimate of 24-hour energy expenditure, an analysis can be made by comparing high and low energy expenditure activities (e.g. sitting for 1 hour vs. physical activity for 1 hour). If data are available, day-to-day variations or estimated energy expenditure for the different mesocycles can also be compared. If you have estimated energy expenditure using Table 2.4, comparisons can be made between the two methods. Crossword Puzzle Answer Key 1. rephosphorylation 2. ATP 3. reliability 4. bioenergetics 5. calorimeter 6. doubly labeled water 7. kilocalorie 8. joule 9. calorie 10. validity 11. adipose tissue 12. TEE Word Find Puzzle Answer Key • 6 forms in which energy exists: atomic, chemical, electrical, mechanical, radiant, thermal • 2 units used to express energy measurements: joule, calorie • 4 food components that yield energy: carbohydrate, fat, protein, alcohol • 2 substances measured in indirect calorimetry: oxygen, carbon dioxide • 2 isotopes measured in doubly labeled water: oxygen-eighteen, deuterium • 3 major components of TEE: metabolism, thermic effect of food, physical activity • 3 non-modifiable factors that influence RMR: age, gender, genetics A T O M I C P W G E N E T I C S H E N L T H E Y T H A P O U R M O A N D A Y C A R B O H Y D R A T E H E L A D S J O T W A O Z S O M B H I E G O S W O E H F W A D L I K I D E U T E R I U M D O N A O U I C R S T R E E N I L A E I L M D T C T A H I S M T L D E O W T X N E S E H E L N M S A H E E A R D A O L C Y W E O A I T R L T C R H O U B I T H E R M I C E F F E C T O F F O O D R A T I I M T T E O A N R D W E L L N L N N O C L I O O X N G I E R M E I O E I M O A R V R I Y Z E C O R G R S B H C Y M L E I P T G O O A F A A R M R A A L O N G T I N E O U L R C R I M A E L S T O X Y G E N E I G H T E E N C Chapter 2 Crossword Puzzle Across Down 3. Ability to reproduce a measurement and/or the consistency of repeated measurements. 6. A measurement technique for determining energy expenditure over a long time period using radioactively labeled hydrogen and oxygen. 7. The amount of heat energy required to raise the temperature of 1 kilogram of water 1ºC. 8. The work done by a force of 1 Newton acting to move an object 1 meter. 10. Ability to measure accurately what was intended to be measured. 11. Tissue made up of fat cells. 12. The amount of energy that is required by the body, typically determined over the course of a 24-hour day. 1. Reestablishing a chemical phosphate bond (e.g., ADP to ATP). 2. A chemical compound that provides most of the energy to cells. 4. The process of converting food into biologically useful forms of energy. 5. A device that measures energy content of food or energy expenditure. 9. The amount of heat energy required to raise the temperature of 1 gram of water by 1ºC. Chapter 2 Word Find Puzzle A T O M I C P W G E N E T I C S H E N L T H E Y T H A P O U R M O A N D A Y C A R B O H Y D R A T E H E L A D S J O T W A O Z S O M B H I E G O S W O E H F W A D L I K I D E U T E R I U M D O N A O U I C R S T R E E N I L A E I L M D T C T A H I S M T L D E O W T X N E S E H E L N M S A H E E A R D A O L C Y W E O A I T R L T C R H O U B I T H E R M I C E F F E C T O F F O O D R A T I I M T T E O A N R D W E L L N L N N O C L I O O X N G I E R M E I O E I M O A R V R I Y Z E C O R G R S B H C Y M L E I P T G O O A F A A R M R A A L O N G T I N E O U L R C R I M A E L S T O X Y G E N E I G H T E E N C Instructions: In the grid above, find the following words or phrases, and then write them beside each clue. • 6 forms in which energy exists: • 2 units used to express energy measurements: • 4 food components that yield energy: • 2 substances measured in indirect calorimetry: • 2 isotopes measured in doubly labeled water: • 3 major components of TEE: • 3 non-modifiable factors that influence RMR: 1 Crossword and word find contributed by Elesha Feldman Instructor Manual for Nutrition for Sport and Exercise Marie Dunford, J. Andrew Doyle 9781285752495