Nutrition for Active Living: Concepts and Controversies. Energy Systems Overview. Adenosine Triphosphate (ATP) Energy Systems Components

Transcription

1 Nutrition for Active Living: Concepts and Controversies Energy Systems Overview ATP/CP Energy System Anaerobic Energy System Aerobic Energy System NSCA South Carolina State Clinic Alicia Powers, PhD Energy Systems Components Adenosine Triphosphate (ATP) Creatine phosphate (CP) Carbohydrate Glucose Glycogen Fat Free fatty acids Triglycerides Protein Amino acids Adenosine Triphosphate (ATP) Basic form of energy for cells Breaking the last high energy bond releases energy Muscle cells store enough ATP to supply 1-3 seconds of energy Additional ATP is made by creatine phosphate, carbohydrate, fat and protein Creatine Phosphate (CP) A high energy compound Broken down to regenerate ATP Can support activity for an additional 10 seconds Anaerobic Metabolism Without oxygen Produces ATP quickly Glucose is partially broken down to yield 2 ATP through anaerobic glycolysis Results in lactic acid accumulation 10 seconds to 3 minutes 1

2 Aerobic Metabolism Aerobic Glycolysis With oxygen Glucose can be completely broken down through aerobic glycolysis to produce ATP 3 minutes to 4 hours Fatty acids can be metabolized aerobically to produce 129 ATP 20 minutes to Amino acids can be metabolized aerobically to produce 15 ATP Energy Systems Overview - Duration Energy Systems Overview - Components Energy Systems Overview Duration and Components Energy Systems Overview Intensity and Components 2

3 Factors Leading to Fatigue All activities Inadequate physical training Mental fatigue Inadequate energy intake Dehydration Delayed nutrient delivery Activities that primarily use ATP/CP Depleted creatine phosphate Anaerobic and aerobic activities Inadequate carbohydrate intake Aerobic activities Anemia Inadequate Energy Intake Increased caloric needs to sustain high levels of physical activity Typically need kcals / kg body weight Sedentary males and females 31 kcals/ kg body weight 150 lb person 2100kcals Recreational athlete kcals/ kg body weight 150 lb person kcals Endurance and strength athlete kcals/ kg body weight 150 lb person kcals Dehydration Decreases blood volume Decreases sweat rate Increases body temperature and increases heart rate Causes fatigue Delayed Nutrient Delivery Fluids and nutrients must be absorbed through the small intestine before these can enter the blood and be used by muscle cells Factors that delay the rate that food and drink leaves the stomach (gastric emptying) will delay nutrient delivery Delayed Nutrient Delivery Factors that delay gastric emptying of fluids and food Fluid or food High fat content High intensity activity Fluid Low volume of fluid consumed Carbohydrate concentrations <4% or >8% Dehydration 3

4 Depleted Creatine Phosphate Inadequate Carbohydrate Intake Creatine supplementation appears to improve sprint performance and the amount of strength gained Creatine supplementation does not improve aerobic performance Creatine can be obtained through the diet from meat Long term effects of creatine supplementation are not known Athletes should consume 55-65% of kcals as carbohydrates However, most athletes do not consume enough kcals to fuel activity, which leads to a distorted view of carbohydrate intake 1715 cal 294 g carb (68%) 1200 cal 210 g carb (70%) Nutrient Needs for the Athlete Macronutrient needs Micronutrient needs Fluid needs Sample meal plan Carbohydrate 55-65% kcals Females: 6-8 g/kg body weight Males: 8-10 g/kg body weight Fat 20-25% kcals 1 g/kg body weight Protein 12-20% kcals Endurance: g/kg body weight Strength: g/kg body weight Maximizing carbohydrate intake Begin exercise with full glycogen stores Consume carbohydrate period to exercise 100 grams 1 hour before exercise or 300 grams 3 hours before exercise If activity lasts more than 60 minutes, consume carbohydrate during activity grams of carbohydrate per hour 20oz. Bottle of Gatorade has 35 grams of carbohydrate Consume carbohydrate after physical activity to replenish glycogen stores grams of carbohydrate immediately after ( kcals) 2 hour window of opportunity maximizes storage 4

5 15 grams of carbohydrate 1 cup of Gatorade 1 whole grain waffle 1 packet of oatmeal 1 slice of whole grain bread 1 granola bar 1 small orange 2 carrots 2 broccoli spears 1 veggie burger 10 ounces of skim milk 1 T. pancake syrup 30 grams of carbohydrate 2 oz. whole grain bagel 1 cup whole grain cereal ¾cup whole grain pasta 1 cup chili with beans 1 cup apple juice 1 large apple 1 banana 45 grams of carbohydrate 1 cup brown rice 4 Fig newtons 1 energy bar ½cup Grape Nuts Micronutrient Needs Athletes may need additional nutrients such as B vitamins Calcium iron Fluid Needs Before exercise Maintain adequate fluid intake prior to event Drink about 2 cups of fluid 2 hours before exercise to allow for absorption and excretion before event During exercise Drink 1 cup every 15 minutes Many athletes prefer cool, flavored beverages Exercise > 60 minutes can be enhanced with beverages containing 6% carbohydrate and small amounts of electrolytes After exercise Consume 16 ounces of fluid for every pound of body weight lost during exercise Sample Meal Plan Early morning snack 1 slice whole wheat toast 1 tsp. jam ½ cup apple juice Breakfast ½cup orange juice 1 cup strawberries 1 egg 1.5 cups whole grain cereal 1 cup 1% milk 1 slice whole wheat toast 1 tsp. margarine and jam Mid morning snack 1 whole grain bagel 1 tsp. margarine and jam 1 cup water Lunch 4 oz. turkey on whole wheat with mayo, lettuce, and tomato 1 apple 1/3 cup potato salad 8 oz. cranberry juice Afternoon snack 1 oz. string cheese 1 oz. pretzels 1 cup grapes Dinner Chicken stir-fry 4 oz. chicken with 2 cups broccoli, red pepper, carrots 2 tsp. vegetable oil 1 T. soy sauce 2/3 cup cooked rice 1 orange 1 cup iced tea Evening snack 1 cup 1% milk 5 graham crackers Totals 3,000 calories Carbs: 483 g (63%) Protein: 139 g (18%) Fat: 64 g (19%) 5