Nutrition, Fitness & Sport

1. Nutrition, Fitness & Sport Position Paper of DC, ADA & Am.College Sports Medicine

2. Joint Position Paper • “…physical activity, athletic performance, and recovery from exercise are enhanced by optimal nutrition” • “…appropriate selection of food and fluids, timing and intake, and supplement choices for optimal health and exercise performance” Rodriguez, DiMarco, & Langley, 2009

3. Energy Needs • What factors affect energy needs of athletes? • What sports might see weight cycling by competitors?

4. Weight Loss and Physical Activity • Weight loss aims to reduce fat • Rapid weight loss • lean tissue/muscle • Fluid • Increased chance of regain • Is weight the only way body composition changes are seen?

5. Body Composition • Standards • BMI 20-25 • % body fat – males 15-18%; females 20-25% • Minimum level for health • – males 5%; females 12% • Why are body weight and weight for height not good indicators of healthy body size?

6. Body Composition • Techniques to measure/estimate body composition • Hydrostatic (under water) weighing • Air displacement plethysmography • DEXA • Anthropomtric measures – skinfolds • Bioelectrical impedence

7. Hydrostatic Weighing

8. Air Displacement Plethysmography

9. DEXA

10. Skinfolds

11. Bioelectric Impedance

12. Energy Recommendations • Accepted macronutrient Distribution Ranges • Recommended intakes of energy-yielding nutrients • CHO – 7-8 g/kg • Pro – 1.2-1.4 g/kg endurance • 1.2-1.7 g/kg strength • Fat – 20-30%

13. Nutrients • Do athletes require more protein than non-athletes? • 0.8-1.2-1.5 g/kg • Which minerals are of primary concern with athletes?

14. Vitamins & Minerals • Micronutrients of concern in athletes • Calcium • Vitamin D • B vitamins • Iron • Zinc • Magnesium • Antioxidants • Vitamins C & A, beta carotene, selenium

15. Hydration • Important to athletes • Heat production • Affects muscle strength, endurance and coordination • Cramping, heat exhaustion and heat stroke all of concern • What conditions create dehydration risk?

16. Hydration • How can one ensure maximal hydration? • 5-7 mL/kg 4 hr before event • Aim to prevent loss over 2% body wt • Replace sweat losses • 1-1.3 L/kg lost beginning early after event • Are specialized products needed to ensure adequate hydration?

17. Sodium (Na) in Sports Drinks • Not needed, unless exercising strenuously for more than 1 hour • 600 mL bottle Gatorade contains ~275 mg Na • Daily Na limit 1500-2400 mg • Not for refreshment or snack • Flavoured water better choice if plain water not personally acceptable

18. Training Diet • 2 fundamental differences between athlete’s diet and general population? • Pre-exercise meal (2-4 hr before event) • Sufficient fluid, low in fat and fibre, 200-300g CHO, some protein, familiar foods • During • CHO in form of glucose 0.7 g/kg extends endurance performance – every 15-20 min • Post-game • Depends on timing of next event • Not needed if over 1 day until next intense workout • CHO within 30 minutes • 1-2 g/kg every 2 hr for 6 hr • High GI foods replace glycogen losses better

19. Ergogenic Aids • How should ergogenic aids be evaluated? • What are some of the ergogenic aids currently marketed? • What types of effects have been proven for these substances?

20. Nutritional Professional • Career path: • Undergraduate, internship, and work experience • Knowledge of exercise science and business • At least 1-2 years employment in dietetics • What roles does the nutrition professional have in the area of sports nutrition?

21. Required Reading • Lichtenstein, & Ludwig, 2010. Bringing back home economics education. • James, & Adams, 1998. Curriculum integration in nutrition and mathematics. • Graham, Beall, et al., 2005. Use of school gardens in academic instruction. • NS Dept. of Education & Health Promotion and Protection. Food and nutrition policy for Nova Scotia schools (web)