Sports Nutrition FSHN 185 Spring 2013

1. Sports NutritionFSHN 185 Spring 2013 Joy Galloway Graduate Student of Nutrition Science

2. http://www.youtube.com/watch?v=IucEW2zSzCQ

3. Overview of Sports Nutrition • What makes a person fit? • How do anaerobic and aerobic metabolism differ? • What are special nutritional needs of athletes? • What are ergogenic aids? • What are physical activity recommendations?

4. What Makes a Person “FIT”? • Fitness = a set of attributes related to the ability to perform routine physical activities without undue fatigue 2012 USA Men’s Swim Team

5. Some Health Benefits of Fitness • Physical: Reduced Risk of Chronic Disease & Mortality (CVD, T2 Diabetes, Some Cancers & Joint Disorders) • Psychological: Improves Mood, Self-Esteem, & Overall Well-Being

6. Components of Fitness Body Composition Flexibility Cardiorespiratory Endurance Muscle Strength & Endurance

7. Components of Fitness:Body Composition

8. Components of Fitness:Flexibility Range of motion— How far can you bend and stretch your muscles & ligaments?

9. Components of Fitness:Cardiorespiratory Endurance • Ability to use oxygen • Measured by aerobic capacity (“VO2 Max”) • Enhanced by aerobic exercise • Decreases resting heart rate / improves cardiovascular efficiency

10. Cardiorespiratory EnduranceAerobic Capacity VO2 Max = mL/kg/min Oxygen the body can use to make ATP Is also related to #RBC’s in body & iron status

11. Aerobic CapacityVO2 Max Values

12. Components of Fitness:Muscular Strength & Endurance • Muscular strength: force exerted • Muscular endurance: ability to maintain activities requiring strength • Hypertrophy = growth • Atrophy = loss …Events requiring Muscular Strength? …Events requiring Muscular Endurance?

13. Aerobic vs Anaerobic MetabolismHow Do They Differ?What Does This Mean Nutritionally?? Aerobic Anaerobic

14. Anaerobic vs Aerobic Metabolism Amount of ATP

15. Exercise Duration & Fuel Use

16. Aerobic Metabolism Occurs in mitochondria of cell Mitochondria increase in number and size with training! Requires oxygen Can utilize fatty acids, amino acids, and glucose for fuel With Oxygen!

17. Anaerobic Metabolism Occurs in cytosol of cell Relies solely on glucose for glycolysis Intermediates in glycolysis provide electrons for electron transport chain in mitochondria (more ATP!) Events of short duration! <2-3min …But anaerobic and aerobic metabolism often occur simultaneously! Without oxygen!

18. PRACTICE Anaerobic & Aerobic Julie Galloway, English Channel swimmer. 9hrs 51min

19. PRACTICE Anaerobic & Aerobic Ray Lewis, linebacker for Baltimore Ravens

20. PRACTICE Anaerobic & Aerobic Ryan Lochte, WR 200 medley, 1min 49sec

21. PRACTICE Anaerobic & Aerobic Laird Hamilton, professional surfer

22. Factors Influencing the Fuel Mix During Exercise 1) Intensity of Exercise ↑intensity → ↑CHO use 2) Duration of Activity ↑duration → ↑Fat use 3) State of Training ↑endurance training → ↑Fat use

23. Sources of energy for muscle at 3 different intensities of exercise *after about 30 minutes of exercise

24. When Fuel Runs Out! http://www.youtube.com/watch?v=LKhkvSRQZYo

25. Athletes’ NeedsEnergy

26. Athletes’ NeedsEnergy • Female athlete triad: • Disordered Eating • Amenorrhea • Osteoporosis • More common in: • Weight-bearing sports (e.g. cross-country) • Aesthetic sports (e.g. gymnastics, diving)

27. Athletes’ NeedsMacronutrients Protein 10 to 15% of kcal Fat 20 to 30% CHO 55 to 70% • Longer duration training →↑CHO need • Protein 0.8 to 2.0 g/kg body weight • Percentage values assume athletes are meeting energy needs. • Percentages can be very different for athletes attempting weight loss.

28. Protein NeedsExtent of Training & Sources Dietary Reference Intakes, 2002 ACSM/ADA/Dietitians of Canada Position Statement: Nutrition & Athletic Performance, 2001

29. Carbohydrate NeedsType & Intensity of Training 6-10g CHO/kg body weight = recommendation (text p.369)

30. Athletes’ NeedsMicronutrients • Sodium & hyponatremia • Maintains fluid balance in cells • Allows for neural firing • Problem with water-only fluid replacement in long events • Iron & anemia • Exercise increases use of iron • Increased iron-requiring protein synthesis • Increased loss through feces, urine, and sweat • Exercise increases need for iron • Females and vegetarians at greater risk

31. Iron’s Role in Exercise http://www.youtube.com/watch?v=eor6EK_JP40&feature=fvwrel

32. Questions so far?

33. Athletes’ NeedsWater Water is crucial for: • Blood volume • maintaining low heart rate • delivering nutrients and oxygen • removing wastes • Maintaining low body temperature • carrying heat to periphery • producing sweat …1.5L/hour!

34. Why does the body lose so much water during exercise? • Working muscles → heat • Blood flow carries heat to the skin • Evaporation of water from the body surface is the most efficient way to remove heat • **water both transports and removes heat** Sweat loss ~ 1.5 Liter (~6cups) / Hour

35. Dehydration Impairs Athletic Performance Water loss as little as 2% of body weight can impair physical and mental performance. 2% weight loss for 150 lb person = 3 lbs 1.5 liters = ~ 1.5 quarts = 3 lbs

36. Dehydration & Heat-Related Illness • Heat Cramps • Involuntary muscle spasms caused by heat & electrolyte loss. • Heat Exhaustion • Rapid heart rate, low blood pressure, disorientation, loss of consciousness. • Heat Stroke • Can be fatal. Body temp over 105F. Inability to produce sweat. Extreme confusion, loss of consciousness, death.

37. Athletes’ NeedsWater • Before exercise, drink enough to be fully hydrated. ~2 cups usually. • During exercise, drink enough to prevent weight loss. 6-12oz every 15-20min. • If you’re thirsty, you’re already dehydrated! • After exercise, rehydrate! 16-24oz per pound lost, or 16oz immediately+. • Cooler water is absorbed faster. • Water with 6-8%CHO is absorbed faster.

38. Optimizing Performance Nutrition is Important Before, During, & After Competition

39. Optimizing PerformanceBefore • Begin properly hydrated. • Maximize glycogen stores.

40. Controversial on best method • ~3 days before race, consume 10-12g CHO/kg (140lb ~2800kcal CHO) • Can DOUBLE glycogen stores • Holds 3g water per g glycogen • Can really only be helpful for events >90min Carbo-Loading http://www.youtube.com/watch?v=9-e5y-3dyUs

41. Optimizing PerformanceBefore • Begin properly hydrated. • Maximize glycogen stores. • Carbo Loading (10-12g Cho/kg) to boost glycogen stores. • Important for competitions over 90min. • Extra benefit of storing 3g water per g glycogen. • Pre-exercise meal ~300kcal high in Cho. • Low fat & fiber to minimize GI distress & bloating. • Caution with fructose & diarrhea. • Your gut is trainable!!

42. Optimizing PerformanceDuring • Prevent excess fluid loss • CHO during exercise if lasts >1hr can help maintain glycogen stores • Glucose & fructose combination • In sports drink or a gel or snack • 30-60g/hr recommended • Sodium during exercise >1hr, especially >3hrs • In most sports drinks • Improves water and CHO absorption • Stimulates thirst

43. Optimizing PerformanceAfter • Replenish fluid (ASAP), electrolytes, and glycogen lost • Provide protein to build and repair muscle tissue • High CHO snack within 30min (glycogen window!) • Enhanced repair with some protein • 1.0-1.5g/kg CHO for training • Regular 55% CHO diet for regular exercisers

44. Ergogenic Aids Substances, appliances, or procedures that improve athletic performance

45. Ergogenic AidsVitamins & Minerals Not really an Ergogenic Aid, because typically do not enhance performance at all unless there was a deficiency. Can cause harmful toxicity!

46. Ergogenic AidsBuilding Muscle • Protein= Usually adequate in diet of adequate Calories. • Growth hormone= Banned by WADA. Improves anaerobic exercise capacity but can cause disfigurement and fatal heart dysfunction. • Amino acids= Unhelpful with strength training when adequate complete proteins consumed. • Anabolic steroids= Banned by NCAA and IOC. Hormones that mimic effects of testosterone by increasing muscle size and strength, but cause atrophy of testes, water retention, coronary disease, liver disease, and severe mood swings.

47. Ergogenic AidsEnhancing Short, Intense Activities Supplements for improving quick bursts of intense activity: • Beta-hydroxy-beta-methylbutyrate (“HMB”) = dubious! • Bicarbonate (baking soda) = some results show delayed fatigue due to its pH stabilization • BUT causes cramps & diarrhea • …Needs more research! • Creatine = found naturally in muscle (PCr system) • Used for <30sec activity • BUT body adapts to creatine production • <5g/day appears safe but FDA recommends consulting physician first

48. Ergogenic AidsEnhancing Endurance • Carnitine = needed to transport FA to mitochondria • But the body makes all we need! • MCT = quickly absorbed FA’s • But haven’t shown to help performance! • Caffeine = enhances release of FA’s • Preserves glycogen stores & delays fatigue • Improves alertness & concentration • But can cause GI distress • Can improve endurance if take 3-6mg/kg within 1hr (2.5cups of coffee) • EPO = stimulates bone marrow to produce RBCs • Banned substances, commonly abused by cyclists • Can cause heart attacks & stroke

49. Physical Activity Recommendations 32% of Americans get NO physical activity in their leisure time!

50. Physical Activity Recommendations • 150min of moderate-intensity or 75min of vigorous-intensity aerobic zone exercise/wk • Aerobic zone = 60-85% of HR max • & 2 days/wk of muscle-strengthening exercises • Nonconsecutive days • Recovery important for muscle-strengthening exercise & for serious athletes to prevent “overtraining syndrome”