1. “Aside from the limits imposed by heredity and the physical improvements associated with training, no factor plays a bigger role in exercise performance than does nutrition.” Dr. David Costill, 1988

2. Energy Balance

3. Hypothetical daily energy needs of an Ironman triathlete in training. ActivityMETSDuration (h) Energy Expenditure (kcal) Sleep0.98.0540 Office work1.58.0900 Running (7.5 mph)*13.50.8*810 Swimming (2 mph)*8.00.5*318 Bicycling (18.6 mph)*12.01.7*1,530 Home activities (e.g. cooking, washing dishes, etc.) 2.53.0563 Miscellaneous activities (reading newspaper, talking on phone, etc.) 1.32.0195 4,856 *Based on data from O’Toole, 1989. Energy expenditure calculated as: (METS  75 kg body weight  hours of activity = kcal)

4. Daily Energy Intakes of Elite Athletes

5. Map of the Trek Torry LarsenRune Gjeldnes WR 2,928 km Unsupported Ski Trek March - June, 1996

6. WR 2,928 km Ski Trek Details 2,928 km (1,815 miles) in 83 days 9 hrs/d of trekking (~22 miles/d) Each pulling 150 kg (330 lb sled) Average energy intake was 6,000 kcal/d Average weight loss was only 5.3 kg (~12 lbs) and 4% reduction in body fat (DEXA) Average weight loss of Army Rangers during 64 days of training is 10 – 20 kg (22 – 44 lbs)!

7. Macronutrients

8. 60 -70% of kcal 350-600g/d 5-10g/kg/d CHO PRO FAT 15-25% of kcal 15% of kcal 1.2-1.8g/kg/d Macronutrient Composition and Performance: Overview

9. Dietary Protein

10. 0.3 0.5 0.7 0.9 1.1 1.3 1.5 Protein Intake (g/kg/d) 80 60 40 20 0 -20 -40 -60 -80 Nitrogen Balance (mg/kg/d) RDA Meredith et al., 1989 Mean =.94g/kg/d

11. 300 250 200 150 100 50 Whole Body Protein Synthesis (mg/kg/hr) 0.9 1.4 2.4 Protein Intake (g/kg/d) Sedentary Strength Athletes Tarnopolsky et al., 1992 * *

12. Current Protein Intake Recommendations

13. Protein and Amino Acid Contents of Common Foods and Popular Supplements

14. Dietary Carbohydrate

15. Why Are Carbohydrates So Important? í Carbohydrates are the primary muscular fuel source for intense exercise

16. FAT CHO Adapted from: Brooks and Mercier, 1994 The “Crossover Concept”

17. Adapted from: Romijn et al., 1993

18. Why Are Carbohydrates So Important? í Carbohydrates are the primary muscular fuel source for intense exercise í Carbohydrate body stores are limited; when depleted, athletes cannot exercise intensely and experience fatigue

19. Adapted from: Bergstrom and Hultman, 1967

20. Adapted from: Gollnick, 1974

21. Adapted from: Bergstrom et al., 1967  Low CHO Diet  Normal Diet  High CHO Diet

22. Why Are Carbohydrates So Important? í Carbohydrates are the primary muscular fuel source for intense exercise í Carbohydrate body stores are limited; when depleted, athletes cannot exercise intensely and experience fatigue í Athletes who train regularly and intensely require more dietary carbohydrates to replenish what is used

23. Adapted from: Costill, 1985

24. Are athletes eating enough carbohydrates?

25. Recommendations for Training í Absolute CHO intakes should approach 350-600g/d or 5-10g/kg/d í The % of calories coming from CHO is not as important as long as absolute needs are met

26. Adapted from: Nieman et al., 1989

28. Data from: Lamb et al., 1990

30. Why Are Carbohydrates So Important? í Carbohydrates are the primary muscular fuel source for intense exercise í Carbohydrate body stores are limited; when depleted, athletes cannot exercise intensely and experience fatigue í Athletes who train regularly and intensely require more dietary carbohydrates to replenish what is used í Carbohydrates consumed before, during, and after exercise maximize performance

36. Sports Drinks

37. Adapted from: McConell et al., 1999

38. Adapted from: Tsintzas et al., 1993

39. Adapted from: Wright et al., 1991

40. Dorando Pietri, 1908 Olympic Marathon Carbohydrates and Performance

41. Carbohydrates in the post-exercise period: Glycogen Resynthesis

42. * Adapted from: Fallowfield et al., 1993

44. Nutrition and Athletic Performance: Summary Number one nutritional priority is maintaining energy balance Athlete protein needs are higher than the RDA, but athletes* already consume even more than the upper scientific recommendations Carbohydrate needs are best expressed on a g/kg/d basis (or in absolute terms: 350-600g/d) Carbohydrates improve athletic performance for endurance exercise (> 90 continuous minutes)