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After studying this chapter you will be able to understand: Nutrition and physical performance; energy systems, muscles, and physical performance; optimal nutrition for exercise performance; energy intake and exercise; carbohydrate and exercise; dietary fat and exercise; protein and exercise;...
Chapter Nutrition for Physical Performance Nutrition and Physical Performance • • “Exercise is medicine” Physical fitness – Cardiorespiratory fitness – Muscular strength – Muscular endurance – Body composition – Flexibility Energy Systems, Muscles, and Physical Performance • ATP-CP energy system – Quick source of ATP • Cellular ATP and creatine phosphate – Fuel for to 15 seconds of maximal effort • Energy Systems, Muscles, and Physical Performance Lactic Acid Energy System – – Breakdown of glucose to lactic acid (lactate) • Doesn’t require oxygen Rise in acidity triggers muscle fatigue • Energy Systems, Muscles, and Physical Performance Oxygen Energy System – Breakdown of carbohydrate and fat for energy • Requires oxygen • Produces ATP more slowly Energy Systems, Muscles, and Physical Performance • • Teamwork in Energy Production – Anaerobic systems – Aerobic systems Glycogen Depletion – Steady drop for first 1.5 hours – Entirely depleted ~ hours Carbohydrate and Exercise • Carbohydrate intake – Before exercise • Easily digested foods/beverages – Pre-exercise meals and glycemic index • Measure food to monitor its effects, which can raise blood glucose Carbohydrate and Exercise • Carbohydrate intake – During exercise • Sports drinks (4–8% carbohydrate) – After exercise • Replenish glycogen stores – to 1.5 grams carbohydrate per kg both 30 minutes and hours after exercise Dietary Fat and Exercise • Fat Intake – Major fuel source for endurance activities – High-fat diet not needed – Recommendations • Moderate fat intake: 20–35% of calories • Limit saturated fat to less than 10% of energy • Avoid trans fat as much as possible Protein and Exercise • • • • Protein Recommendations – Adults: 0.8 grams per kg body weight – Endurance athletes: 1.2–1.7 g/kg – Resistance-trained athletes: 1.6–1.7 g/kg Protein Sources – Foods: lean meats, fish, low-fat dairy, and egg whites Protein Intake After Exercise – Helps replenish glycogen Dangers of high-protein intake Vitamins, Minerals, and Athletic Performance • • B vitamins – Needed for energy metabolism – Choose variety of whole grains, fruits, and vegetables Calcium – Needed for normal muscle function and strong bones – Low-fat dairy products – Adequate intake may be a problem for females Vitamins, Minerals, and Athletic Performance • • Iron – Needed for oxygen delivery and energy production – Athletes have higher losses – Lean red meats, vegetables, and enriched grains Other trace minerals – Copper and zinc – Avoid high-dose supplements Fluid Needs During Extensive Exercise • Exercise and fluid loss – Increased losses from sweat – Increased with heat, humidity – Risk for dehydration Fluid Needs During Extensive Exercise • Hydration – Adequate fluids before, during, after exercise – Water vs sports drinks • Duration • Intensity • Environmental factors Nutrition Needs of Youth in Sports • Priority on growth and development – Meals/snacks both before and after exercise – Caution: High tolerance for exercise in heat Nutrition Supplements and Ergogenic Aids • Include products and practices that – Provide calories – Provide vitamins and minerals – Contribute to performance and enhance recovery – Are believed to stimulate and maintain muscle growth Nutrition Supplements and Ergogenic Aids • Regulation and concerns about dietary and herbal supplements – Bypass FDA safety and effectiveness regulations – Possibility of product contamination Nutrition Supplements and Ergogenic Aids • • • • • Convenience supplements – Meal replacements, ready-to-drink supplements, energy bars, etc Weight-gain powders – Add an extra 500–1,000 calories/day Amino acids – HMB, glutamine Coenzyme Q10 Creatine Nutrition Supplements and Ergogenic Aids • • • • • • • • Creatine Antioxidants Caffeine Ephedrine Sodium bicarbonate Chromium Iron Green tea extract Weight and Body Composition • • Weight gain – Increase muscle and reduce fat Weight loss – Lose fat and maintain muscle – Avoid dangerous weight-loss practices ... Physical Performance • ATP-CP energy system – Quick source of ATP • Cellular ATP and creatine phosphate – Fuel for to 15 seconds of maximal effort • Energy Systems, Muscles, and Physical Performance. .. Muscles, and Physical Performance • Muscles and Muscle Fibers – Slow-twitch fibers – Fast-twitch fibers • Relative proportion determined by genetics Optimal Nutrition for Exercise Performance •... Daily weigh-ins are discouraged – Protein recommendations 1. 2-1 .7 g/kg – Fat intake 2 0-3 5% of total energy intake Optimal Nutrition for Exercise Performance • General recommendations – Risk for micronutient