1. Fundamentals of Exercise for Nutrition By Jennifer Turley and Joan Thompson © 2013 Cengage Module 4.5

2. Presentation Overview  Fuel and Utilization During Exercise  Carbohydrates  Proteins  Fats  Thermal Regulation and Hydration

3. Fuel Utilization During Exercise  ATP production is primarily from carbohydrate and fat  As the intensity of the exercise increases, the percent of carbohydrates used to produce ATP increases  Nutrition supplies the substrate or fuel (carbohydrate, fat and protein) and the essential structural components of enzymes (cofactors) needed to drive chemical reactions to generate ATP through:  Glycolysis  The citric acid cycle  The electron transport chain.

5. Carbohydrates  The objectives of dietary carbohydrate management is to maintain blood sugar and replete muscle glycogen  Carbohydrates as fuels support high intensity exercise  Carbohydrates are limited in the body

6. Carbohydrates in the body  Blood Glucose  4.5 grams of glucose total  Constantly used by RBC and CNS  Liver Glycogen  75 (to 100) grams  Used to maintain blood glucose  Muscle Glycogen  Amount of exercise and dietary carb intake determines the amount  Used to produce ATP in the muscle during exercise

7. Carb Management for Enhanced Exercise Performance  Diet and exercise influence glycogen stores in the muscle  High carbohydrate intake (7-10g/Kg/day)  60-65% of Calories from carbohydrate  The timing of the carbohydrate intake in relation to exercise is important:  Prior to the Exercise (4 hours before or 2 hours before and 5- 10 minutes before)  During the Exercise (about every 15 or 20 minutes)  After the Exercise (immediately after and again 2-6 hours later)

8. Timing and Amount of Intake 68 Kg Exchange List Pattern 68 Kg Food and Beverage Options for Exchange List Patterns 4 hours prior 4 gm/kg 1.82 gm/lb 10 starch 5 fruit 3 other carbohydrate 2 cups pasta (90 g) 1 bagel (60 g) 1 cup juice (45 g) 1 cup fat-free frozen yogurt (45 g) 1 large banana (30 g) (270 g total) 2 hours prior 2 gm/kg 0.91 gm/lb 6 starch 3 fruit exchanges 1.33 cups pasta (60 g) 2 slices of bread (30 g) 1 cup juice (45 g) (135 g total) 5-10 minutes prior 0.5-1 gm/kg 0.23-0.45 gm/lb 2-4 other carbohydrate Exchanges 1-2 low-fat sport bars (2 ounce size) or the equivalent of 2-4 tablespoons of sugar (34-68 g total) During 60 gm/hr 2-4 other carbohydrate exchanges/hour A six percent glucose electrolyte replacement solution provides about 15 grams of carbohydrate per cup of fluid (1 tablespoon of sugar and ¼ teaspoon of salt per one cup water, drink 2-4 cups per hour) Immediately after Carbs: 1.65 gm/kg or 0.75 gm/lb Protein: 0.55 gm/kg or 0.25 gm/lb 7 starches, 3 meats Or 2 milk, 2 fruit, 4 starches, 2 meats Or 1 milk, 2 fruit, 4 starches, 3 meat 2 cups low-fat milk (24 g carbs, 16 g protein) 2 cup ready-to-eat cereal (60 g carbs, 12 g protein) 4 tablespoons raisins (30 g carbs) 2 egg whites (14 g protein) (114 grams of carbohydrate and 42 grams of protein total) 2-6 hours after Carbs: 1.65 gm/kg or 0.75 gm/lb Protein: 0.55 gm/kg or 0.25 gm/lb 5 starches, 2.5 vegetables, 3 meats, 2 fruits or similar to immediately after meal 3 ounces chicken (21 g protein) 1 large baked potato (60 g carbs, 12 g protein) 1.25 cups cooked broccoli (12 g carbs, 5 g protein) 1 small roll (15 g carbs) 1 large pear (30 g carbs) (117 grams of carbohydrate and 38 grams of protein)

9. Recovery Nutrition After Exercise  Muscle glycogen repletion begins immediately after the exercise and prepares the energy stores for the next workout  Consuming meals that provide the combination of carbohydrate and protein at a 3g : 1g ratio promotes muscle glycogen repletion

10. Proteins  Athletes require more protein to stay in nitrogen balance as compared to individuals who are meeting their DRI for physical activity  The range is 1.2 to 1.6 grams of protein per kilogram of body weight… average adult DRI=.8g/ kg  To support lean body mass gains, a strenuous weight- lifting program, 1.6 grams of protein per kilogram of body weight and a positive energy balance of 200 Calories is needed  High quality or the complement equivalent is needed for 2/3 of the protein consumed

11. Fats  The dietary fat recommendations made for the athlete are the same that support health and meet the DRIs  Consume low-fat foods prior to exercise and a low-fat (20-25% of Calories) diet in general  Adding MUFAs may be the best choice of fats if weight gain is desired  MCT have been touted to be useful during exercise, but not proven, however, they are useful for malabsorption syndromes due to their direct absorption into the blood stream

12. Thermal Regulation & Hydration  The ability to keep the body cooled during exercise is key to exercise capacity and avoiding injury  A lot of heat is generated in the body due to the inefficiencies of energy transfer to make ATP  Sweating creates the evaporative cooling system employed during exercise to keep the core body temperature in a functional range.

13. Understanding & Controlling BT  The core body temperature rises during exercise  If the core body temperature >104 o F, exercise capacity diminishes and risk of thermal injury increases  Fluid, salt, and other components are lost in sweat during exercise – about a liter of fluid per hour of exercise, and 2.6 grams of salt per liter  Salt (NaCl) is 40% sodium, ½ t salt replaces the sodium lost in 1 hour of vigorous exercise

14. Dehydration  Hydration  The fluid lost in sweat comes from the blood stream  The plasma volume is the fluid reserve for sweat  This is why there is such large deterioration in aerobic exercise capacity due to dehydration

15. Dehydration  Hydration  The sensation of thirst signifies 2% dehydration, cardiovascular and aerobic function is reduced  5% dehydration, serious thermal injury risk  The body can absorb 1 liter of fluid per hour  Replacing fluids (cool, dilute, small, and frequent amounts) during strenuous exercise is important:  1 cup at 41 o F, every 10-15 minutes  Drink without thirst to avoid dehydration

16. Hydration Importance of hydration during exercise Cardiovascular demise during dehydration  Optimize muscle strength  Optimize aerobic capacity  Prevention of thermal injury which include dizziness, cramping, fainting, heat exhaustion and heat stroke  Pool of fluid to draw upon for sweat loss is the blood stream.  The cardiovascular system is affected dramatically by fluid losses.  Plasma volume decreases  Osmolarity of the blood increases  Blood pressure goes down.  Constriction of the blood vessels  Increase in heart rate  Decrease in heart filling  Decrease in cardiac output  Decreased sweating  Increase in core body temperature

17. Summary  Fuel and hydration management are so influential on exercise capacity  As the intensity of the exercise increases, so does the percent of carbohydrate used to produce ATP  Carbohydrate stores in the body are limited  Dietary carbohydrate intake before, during, and after exhaustive exercise can enhance exercise performance  A combination of carbohydrate and protein (3:1 ratio) consumed after exercise can support muscle glycogen repletion. References for this presentation are the same as those for this topic found in module 3 of the textbook

18. Summary  The protein needs of most competitive athletes range between 1.2 to 1.6 grams of protein per kilogram of body weight per day  A low fat diet that provides all of the essential fatty acids in adequate amounts can support most athletic endeavors  Adequate hydration from fluid and salt intake is important for aerobic performance and avoiding thermal injury References for this presentation are the same as those for this topic found in module 3 of the textbook