1. CHAPTER 11 NUTRITION, EXERCISE AND SPORTS

2. LEARNING OUTCOMES Explain the benefits of physical activity Discuss the energy sources for muscles and human performance Describe how the body responds to physical activity Describe main nutrition concepts used when designing diet plans for athletes 2

3. LEARNING OUTCOMES Describe the fluid needs of athletes and how to avoid dehydration and hyponatremia Describe how the composition of food eaten before, during and after exercise training sessions can effect performance Explain the role of ergogenic aids and describe their effect on athletic performance 3

4. TRUE OR FALSE? Most people in the US are physically fit. Athletes should eat immediately after training. Vitamin and mineral supplements improve athletic performance. Everyone who exercises should consume sports drinks. 4

5. WHAT ARE THE BENEFITS OF EXERCISE? 5

6. CHARACTERISTICS OF A GOOD FITNESS PROGRAM Mode Duration Frequency Intensity Progression Consistency Variety 6

7. MODE 7

8. DURATION AND FREQUENCY Dietary Guidelines 30 minutes moderate physical activity for disease prevention 60 minutes moderate to vigorous activity for weight control 90 minutes moderate activity to maintain a weight loss Frequency: Most days of the week Continuous or broken up? 8

9. INTENSITY 9

10. 10

11. PROGRESSION, CONSISTENCY AND VARIETY Progression Initiation (3-6 weeks): body adapts Improvement (takes 5-6 months): maximize intensity and duration Maintain Consistency Variety 11

12. ENERGY SOURCES FOR MUSCLE USE ATP: Immediately usable energy Lasts 2-4 seconds Phosphocreatine: Initial resupply of muscle ATP Re-forms ATP from ADP Concentration is 5 times greater than ATP 12

13. 13

14. CARBOHYDRATE Major fuel for short-term, high-intensity and medium-term exercise Anaerobic (short-term, high-intensity) Glycolysis provides energy for 30 seconds to 2 minutes Carbohydrate is only fuel that is used in this process Lactate is byproduct Aerobic (medium to high term) ATP supply is slower but greater 14

15. CARBOHYDRATE Glycogen: storage form on carbohydrate Breaks down to glucose- used for anaerobic and aerobic Muscle glycogen used for short events (<30 minutes) Liver glycogen used for long events-will start to use blood sugar for fuel Exhaustion of glycogen stores: “Hitting the wall” 15

16. 16

17. 17

18. 18

19. FAT Main fuel for prolonged low- intensity exercise (accounts for 50- 90% of fuel in this type of activity) Fat provides more energy, but is less efficient 19

20. FAT AS FUEL Training affects muscle use of fatty acids 20

21. PROTEIN A minor fuel source during exercise (gluconeogenesis) Eating more protein than what the body needs will not build more muscle 21

22. AMDR Acceptable Macronutrient Distribution Ranges for Adults (as a percentage of Calories) for “regular” adults. Protein: 10-35% Fat: 20-35% Carbohydrate: 45-65% 22

23. DIETARY ADVICE FOR ATHLETES Protein Needs 1-1.7 g/kg body weight If an athletes needs are 2000kcals and she weighs 70kg, this means she needs 70-120 grams (14- 24% of total kcal intake). AMDR for Protein: 10-35% 23

24. DIETARY ADVICE FOR ATHLETES Energy Needs vary widely Carbohydrate Needs 5-10 g/kg body weight depending on time/type of exercise. If an athletes needs are 2000kcals and she weighs 70kg, this means she needs 380-680g. Boosting Glycogen Stores Carbohydrate Loading (What? Who? How?) 24

25. DIETARY ADVICE FOR ATHLETES Fat Needs 15-25%, emphasis on unsaturated fats 25

26. FLUID NEEDS Need to replace fluids lost through sweat Heat exhaustion Heat cramps Heat stroke Fluid Intake Goal is to lose no more than 2% body weight Before, during and after exercise Drink 3 cups for every pound lost during exercise 26

27. 27

28. HYDRATION Hyponatremia Sports Drinks Carbohydrates and electrolytes (when needed?) 28

29. FOOD INTAKE Pre-exercise meal High carbohydrate, low fat Fueling during exercise Carbohydrate replenishment for events longer than 60 minutes Recovery meals 30 minutes and 2 hours after exercise 1-2 g of carbohydrate per kg/body weight 29

30. EXAMPLES Pre workout Goal: keep up blood sugar but don’t upset stomach Breakfast drinks Cereal and milk, juice Bread with peanut butter Pasta and milk Baked potato w/sour cream Post workout Goal: Replace glycogen stores to help recover Early simple carbs like juice, soda, sports drink, chocolate milk Later complex carbs like bread, potatoes, rice, pasta 30

31. ERGOGENIC AIDS Substances taken to improve exercise performance Useful in some situations Creatine: increases phosphocreatine so may improve performance in sports that require short bursts of energy, muscle gain is partially from increased water Risks: kidneys Sodium bicarbonate: counter lactic acid buildup for activities where lactate is rapidly made (wrestling) Risks: nausea and diarrhea Caffeine: stimulant, useful is some athletes who don’t regularly drink coffee- NCAA does test 31