Chapter 6

1. Chapter 6 Nutritional Considerations

2. Eating for Sport Performance • American Dietetics Association indicates that eating properly will: • help you train longer and at a higher intensity • delay the onset of fatigue • promote recovery • help your body adapt to workouts • improve body composition and strength • enhance concentration • help maintain healthy immune function • reduce the chance of injury • reduce the risk of heat cramps and stomach aches.

3. Nutrition • Diet influences every aspect of sports participation. • Certified athletic trainers are most knowledgeable about nutrition. • Coaches and athletes often lack adequate nutrition information and incorporate unfounded nutritional practices into training programs.

4. Knowledge of Nutrition • Recent studies (Jacobson et al., 2001; Froiland et al., 2004) • Demonstrated that athletes may be receiving better nutritional education from more reliable sources. • But there is still education to be done because Jacobson et al (2001) reported that only 55% of college athletes received nutritional advice always or often during their college careers

5. Overview of Nutrients • Macronutrients • Carbohydrates • Fats (Lipids) • Protein • Micronutrients • Vitamins • Minerals • Water

6. Carbohydrates • Carbohydrates (CHO) provide energy for high-intensity exercise • Experts recommend 60% to 70% of daily calories be supplied by CHO. • Each gram of CHO provides 4 kilocalories. • Average person stores approximately 1500 to 2000 kcals of CHO, the majority of which is in the form of muscle and liver glycogen. Small portion available as blood glucose. • Carbohydrate loading can benefit athletes involved in aerobic sports, especially activities lasting 60 minutes or more.

7. Carbohydrates • CHO derived from plant sources, primarily grains, seeds, fruits, and vegetables. • Simple CHO – monosaccharides • Typically stimulate insulin release and blood glucose fluctuations. • Foods containing are high caloric and often referred to as empty calories. • Complex CHO – polysaccharides • Whole-grain cereals & breads, vegetables, and fruits. • Dietary fiber (indigestible CHO) essential for digestion.

8. Carbohydrates • Simple and complex CHO are suitable to describe foods, but these do not represent the way they are hydrolyzed and absorbed by the body. • Low Glycemic Index CHO • Cause a steadier rise and decline in blood glucose and insulin. Best for weight management and overall diet. • High Glycemic Index CHO • Typically result in a large and rapid rise in blood glucose and insulin, followed by a rapid decrease in blood glucose. Best for refueling after event.

9. Fats • Fats (lipids) are needed for energy, insulation, and protection of organs. • Experts recommend that fats compose 30% or less of total calories. • Each gram of fat supplies 9 kilocalories. • Fatty acids and glycerol make up fats.

10. Fats • Fatty acids can be saturated or unsaturated. • Saturated - all of the available bonding sites on the fatty acid molecule are occupied by a hydrogen atom. Derived from animal sources (i.e., beef, pork, poultry, and dairy products). Generally solid at room temperature. • Unsaturated fats are structured in such a way as to prevent all of the available bonding sites from being occupied by a hydrogen atom. Plant based. Generally liquid at room temperature.

11. Proteins • Proteins are needed for tissue construction, enzyme reactions, and energy during prolonged exercise. • Experts recommend that proteins compose 10-15%. • Each gram of protein supplies 4 kilocalories. • Proteins are composed of amino acids • 20 different amino acids are used to make thousands of proteins. • 8 are essential amino acids, which cannot be synthesized by the body. Must be ingested in the diet

12. Proteins • Sources include eggs, meats, dairy products, legumes, or grains. • Athletes who are on vegetarian diets must take care to eat foods in the correct combination to provide all of the essential amino acids. • A solution to the problem is for such athletes to include either eggs (ovolactovegetarian), milk products (lactovegetarian), or both to ensure adequate supplies of essential amino acids.

13. Protein Supplementation • Protein supplementation is not recommended because: • Increase saturated fat in the diet • Overstress the liver and kidneys. • NO scientific evidence that protein supplements enhance muscles. • During intense training, 1.2-1.8 grams protein/kg body weight are recommended. • 0.83-1.2 g/kg for sedentary or light exerciser • Normal diet provides adequate protein consumption for intense training.

14. Vitamins • Vitamins have various functions • Regulate biochemical reactions (energy metabolism and cell and tissue generation) • Serving as antioxidants that protect cell structure. • Vitamins contain no caloric value and a balanced diet supplies the RDA. • There are water- and fat-soluble types of vitamins. • Water soluble: Vitamins C, B1, B2, B6, B12, niacin, folic acid, biotin, and pantothenic acid. • Fat soluble: vitamins A, D, E, and K.

15. Minerals • Minerals are elements needed for various body functions. • Provide structure, help maintain normal heart rhythm, assist muscle contractility, promote neural conductivity, and regulate metabolism. • There is no scientific evidence to support taking minerals in excess of RDA for performance. • But endurance athletes may be at an increased risk of iron or calcium deficiency • Iron and Calcium RDAs • Iron:10 mg for males and 18-20 mg for females • Calcium: 1500 mg

16. Vitamins and Minerals • Athletes who do not eat a balanced diet should be advised to include a vitamin and mineral supplement. • A convenient method of supplementation is a daily multivitamin. • But megadoses of vitamins/minerals should be avoided and could result in severe consequences.

17. Water (H2O) • Water is necessary for human performance, as well as survival. • Adult water requirement at rest is approx. 2.5 liters daily, but it can increase to 5–10 liters during heavy exercise, especially in high temperature and humidity. • Water lost during exercise needs to be replaced to maintain body’s fluid balance. • A reduction of body weight of 2-5% can impair function. • Current recommendations are for every 1 lb lost due to sweating, 20-24 oz. of water be consumed.

18. Dietary Habits of Athletes • Seventy percent of university athletes are falling short of their daily caloric needs and 81% of females and 90% of males were not eating the recommended amounts of CHO. (Hilton, 2005). • Collegiate athletes underestimate their carbohydrate needs and overestimate their fat and protein needs. • In fact, 21% believed that protein provides immediate energy and 30% thought that vitamins provide immediate energy. (Jacobson et al., 2001)

19. Dietary Habits of Athletes • Conclusions • Many athletes do not consume proper proportions of CHO, fat and protein. • Many tackle football players consume diets high in protein and fat. • Athletes in sports that require lean bodies tend to eat diets with insufficient calories. • Most athletes’ diets are deficient in important minerals, i.e., calcium, iron, & zinc. • Athletes eat too much “junk food.”

20. Weight Loss and Wrestling • Wrestling is one of only a few sports that match participants on the basis of weight. • Wrestlers often follow unhealthy weight loss procedures to compete in lighter weight categories. • Rapid weight loss occurs via dehydration. • Dehydration occurs through the use of laxatives and diuretics, fluid restriction, artificially induced sweating, and starvation.

21. Weight Loss and Wrestling • Short-term effects of repeated bouts of extreme weight loss include: • Increased blood viscosity. • Blood clots. • Kidney and liver problems. • Ulcers. • Long-term effects may include interference with normal growth and development.

22. Wrestling Minimum Weight Project (WMWP) • Wisconsin instituted WMWP in 1989. • Weight loss must be no more than 3 lbs. of weight loss/week. • A minimum 7% body fat level was established. • Testing of athletes along with nutrition education for coaches was implemented.

23. WMWP • The NFSH has developed a national wrestling rule #1-3-1 that states: • “A medical professional should…establish a minimum (wrestling) weight through… checking body fat and hydration. The recommended minimum body fat should not be lower than 7%.”

24. What Can the Coach Do? • Coaches are an important source of nutrition information. • People planning to enter the coaching profession should take at least one basic college nutrition course. • Attend in-service meetings, professional conferences, or community education programs in sports nutrition. • Subscribe to professional journals that include nutrition articles.

25. What Can the Coach Do? • Locate nutrition experts, including dietitians, university nutrition faculty, or sports medicine staff. • Implement peer-led programs like Athletes Targeting Healthy Exercise & Nutrition Alternatives (ATHENA). (Eliot et al., 2008) • Have athletes keep a record of their diet that is reviewed periodically by a person knowledgeable in nutrition. • When working with children, discuss nutritional needs of the athlete with parents.

26. General Dietary Guidelines for Athletes • Three Goals • Nutritional maintenance and development during training • Pre-competition preparation • Nutrition during competition MyPyramid, www.MyPyramid.gov Sports, Cardiovascular, and Wellness Nutrition practice group (http://www.scandpg.org)

27. Nutrition During Training • Recommendations include: • Tailoring an athlete’s diet to meet individual needs • Consuming: 10-15% calories from protein, 30% from fat, and the remainder from CHO (>55%). • 1.5-2.0 grams of protein/kg of body weight/day. • Little need for vitamin/mineral supplements if diet is well balanced. • Using simple terms when educating young athletes about nutrition.

28. Pre-competition Diets • Experts recommend that the typical pregame meal should be eaten no later than 3 to 4 hours prior to the contest. • Eat low-fat, easy-to-digest foods. • Liquid meals increase hydration and are less likely to cause bloating or “heavy” feeling. • Foods should provide 150 to 300 grams of CHO or 3 to 5 grams/kg of body weight.

29. Nutrition During Competition • One hour of highly intense exercise can reduce liver glycogen by 55% and 2 hours can almost completely deplete both liver and muscle glycogen. • CHO consumption during long-duration exercise (1 to 3 hours at 70% to 80% VO2max ) allows muscle cells to rely on blood glucose for energy. • Recommended fluid source of CHO is 8 oz. of a 5% CHO solution consumed every 15-20 min.

30. Nutrition After Competition • Dietary goals are to replace muscle glycogen and ensure quick recovery. • A carbohydrate intake of approximately 1.0–1.5 g/kg body mass (0.5–0.7 g/lb) during the first 30 min and again every 2 h for 4–6 h will be adequate to replace glycogen stores. • Timing of CHO ingestion is important as glycogen levels will replenish faster if the food is consumed within 30 minutes – 1 hour. • Protein consumed after exercise will provide amino acids for building and repair of muscle tissue.

31. Weight vs. Fat Management • Body weight consists of water, fat, and lean tissue. • Muscle is denser than fat • In order to maintain weight an athlete’s caloric intake must equal caloric expenditure. • Consume more calories per day than the body requires then excess calories are converted to fat. • Fail to consume enough calories to meet the daily requirement then stored fat will be metabolized to form energy. • Severe caloric restrictions (fasting) result in protein breakdown.

32. Weight vs. Fat Management • Percentage of body fat = the ratio of fat to lean body weight • Better measurement for weight management and is commonly referred to as body composition. • Ranges for most active young females are 10-28% and active young males are 5-15%. • Males should have at least 5% body fat. • Females should have a minimum of 8 to 10% body fat. • Percent body fat can be used to accurately calculate an athlete’s minimal competitive weight so they can excel during the season.

33. Minimal Competitive Weight (MCW) • Athletes should only weigh themselves once/week at the same time of day and after going to the bathroom. • Sample Equation: [MCW = LBW/% fat desired] • Determine % fat desired (5%); (1 - % fat desired = 0.95) • A 135 lb athlete with 14% body fat has lean body weight (LBW) = 135 x 0.14 = 18.9 lb fat • 135 lb – 18.9 (fat weight) = 116.10 lb (LBW) • MCW = 116.10/0.95 = 122 lbs

34. Supplements and Ergogenic Aids • Supplements have become very popular with athletes of all calibers. • Supplements can be divided into two categories: Legal and Illegal. • Legal supplements: caffeine, creatine, amino acids, and herbal supplements. • Illegal supplements: anabolic steroids, androstenedione, EPO, GHB, human growth hormone.

35. Supplements and Ergogenic Aids • It is important for the consumer to evaluate the marketing claims, research studies, and safety issues associated with ergogenic aids. (Manore, Meyer, and Thompson, 2009) • Several studies have identified unrecognized risks of supplementation, so consumers should be aware of deceptive marketing techniques including outstanding claims, patents, testimonials, and media campaigns.

36. Most Popular Legal Supplements • Caffeine • Touted to be a safe aid and can provide a boost of energy for the athlete. It is purported to aid endurance activities by assisting substrate metabolism and delaying fatigue. • Ephedra • Stimulant - affects the way the brain recognizes exhaustion during exercise • Very controversial ergogenic aid and has recently been banned because it was linked with over 155 deaths (Hampton, 2005)

37. Most Popular Legal Supplements • Creatine • Has been found to be more helpful for athletes who use short bursts of energy than for endurance athletes. • Produces an increase in energy at the cellular level which allows the athlete to train for longer periods of time. • Adverse effects associated with creatine are kidney damage, fluid retention, muscle cramps, upset stomach, and diarrhea. • There are many published studies on creatine use but they report conflicting results.

38. Most Popular Legal Supplements • Amino Acids • Marketed for muscle building and repair. • Isolated amino acids used for the purpose of muscle building are NOT effective. • Water soluble and cleared and eliminated through the kidneys and urine. Excess can apply extra stress to the urinary system and result in permanent damage. • Herbal Supplements • Herbs produce a stimulatory effect (ginseng, yohimbe, kava) and others produce relaxation to reduce stress in the athlete (chamomile, St. John’s wort). • Drug interactions are possible with other medicines.

39. Illegal Supplements • High doses of anabolic steroids • Athletes can contract blood borne diseases, damage internal organs, increase risk of heart attack, develop aggression and secondary sex characteristics. • Erythropoietin (EPO) • Stimulates red blood cell proliferation. • May take too much and get too many red blood cells circulating. Increases the viscosity of the blood = heart working harder = potential heart failure. • Amphetamines - Stimulant • Gammahydroxybutyrate (GHB) - Depressant

40. Nutrition and Injury Recovery • Weight gain can occur with forced inactivity due to injury. • Recommend cross training during recovery. • Runners can ride stationary bikes or run in swimming pools. • Maintains aerobic fitness while burning excess calories. • Athletes who are ill/injured should reduce total caloric intake until healthy to avoid excess weight gain.