Section+5+eating+for+training+and+competition

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  • If total calories from food exceed daily energy expenditure, excess calories accumulate as fat in adipose tissue.
  • Variety example: Each vegetable form contains a unique set of phytochemicals, so consuming a variety of vegetables provides a broad array of these beneficial food constituents. Balance example: If a person dislikes milk or milk products, the likelihood of calcium deficiency increases because this food group constitutes the major source of calcium. Moderation example: If one meal contains high-fat foods, other meals during the day must contain less fat.
  • Critics maintain that the new approach shifts too much of the burden of responsibility to the individual, who must have access to a computer and the skills to navigate the relatively complicated government site.
  • Carbohydrates: Select fiber-rich foods: whole fruits rather than juices; whole grains (wheat bread, oatmeal, brown rice) rather than refined grains. Salt: Reduce daily salt intake to 2300 mg or less. Alcohol: Up to one drink a day for women, two for men. Activity: At least 30 minutes of moderate activity a day, although children and adolescents need at least 60 minutes a day for healthy growth. Safe to eat: Wash and cook foods properly to avoid food borne illnesses. Refrigerate perishable items promptly.
  • Servings: 6-oz glass of fruit or vegetable juice; a medium-size orange, banana, or apple; one cup of salad greens, about the size of your fist; 1 egg; 1 cup of milk or yogurt; 1 slice of bread; two tablespoons of peanut butter, about the size of a ping-pong ball; one-half cup of chopped fruits and vegetables; three medium asparagus spears, eight carrot sticks, one ear of corn; one-fourth cup of dried fruit like raisins; 3 oz of meat, fish, or poultry, about the size of a deck of playing cards; a teaspoon of butter or mayonnaise, the size of a fingertip; or 2 oz of cheese, the size equivalent of two whole thumbs.
  • Mediterranean: staves off age-related memory loss, heart disease, cancer, and overall mortality rate in healthy, elderly people. Substantially reduces the rate of recurrence after a first myocardial infarction Vegetarian
  • The competitive athlete’s diet usually contains two to four times more protein than recommended values.
  • Adequate research design and methodology has not shown that protein (amino acid) supplementation in any form above the RDA increases muscle mass or improves muscular strength, power, or endurance.
  • A diet of 20% lipid produced poorer endurance performance scores than a diet of identical caloric value containing about 40% lipid.
  • General recommendations for carbohydrate range between 6 and 10 g/kg of body mass per day.
  • Basic recommendations for carbohydrate, lipid, and protein components and the general categories of food sources in a balanced diet.
  • Under these adverse situations, a multivitamin–mineral supplement at recommended dosages can upgrade the micronutrient density of the daily diet.
  • Consuming vitamin C above recommended daily levels (75 mg for women and 90 mg for men) does not protect the general population against upper respiratory tract infection (URTI)
  • A blunted fatty acid metabolism could cause a more rapid than normal depletion of muscle glycogen during exercise.
  • If supplementation proves beneficial, vitamin E may be the most important antioxidant related to exercise. Rich sources of vitamin E in the diet include almonds, sunflower seeds, safflower and corn oils, hazelnuts, tomato sauce, peanuts, mangos, kidney beans, spinach, kiwi, and broccoli.
  • If supplementation proves beneficial, vitamin E may be the most important antioxidant related to exercise. Rich sources of vitamin E in the diet include almonds, sunflower seeds, safflower and corn oils, hazelnuts, tomato sauce, peanuts, mangos, kidney beans, spinach, kiwi, and broccoli.
  • Short- and long-term mineral supplementation above recommended levels does not benefit exercise performance or enhance training responsiveness.
  • Gymnasts, ballet dancers, ice dancers, and weight-class athletes in boxing, wrestling, and judo who engage in arduous training are at high risk for marginal nutrition.
  • If a person trains or competes in the afternoon, breakfast becomes the important meal to optimize glycogen reserves. For late afternoon training or competition, lunch becomes the important source for topping off glycogen stores.
  • The ideal precompetition meal maximizes muscle and liver glycogen storage and provides glucose for intestinal absorption during exercise. A meal that contains relatively little fat and fiber facilitates gastric emptying and minimizes gastrointestinal distress.
  • Contain enough lipid and protein to contribute to satiety. Liquid meals prove particularly effective during day-long swimming and track meets or during tennis, soccer, and basketball tournaments.
  • Some contain dietary supplements such as b-hydroxy-b-methylbutyrate (HMB). Lack the broad array of plant fibers and phytochemicals found in food and contain a relatively high level of saturated fatty acids.
  • Contain between 10 and 50 g of protein per serving. When mixed in water, these powdered nutrient supplements far exceed the recommended protein intake percentage and fall below recommended lipid and carbohydrate percentages.
  • Once absorbed by the small intestine, fructose must first enter the liver for conversion to glucose. This further limits how quickly fructose becomes available as an energy source.
  • Carbohydrate feeding during exercise at 60 to 80% of aerobic capacity postpones fatigue by 15 to 30 minutes, with performance improvement generally ranging between 15 and 35%. A person can ward off fatigue and extend endurance with a single concentrated carbohydrate feeding approximately 30 minutes before anticipated fatigue.
  • Average plasma glucose concentration during prolonged intensity aerobic exercise when subjects consumed either a placebo or glucose polymer.
  • Within 15 minutes after stopping exercise, consume 50 to 75 g of high- to moderate-glycemic carbohydrates. Continue eating 50 to 75 g of carbohydrate every 2 hours until achieving 500 to 700 g or until eating a large high-carbohydrate meal. If immediately ingesting carbohydrate after exercise is not possible, an alternative strategy involves eating meals containing 2.5 g of high-glycemic carbohydrate per kg body mass at 2, 4, 6, 8, and 22 hours post exercise.
  • Changes in muscle glycogen with various carbohydrate feedings of similar energy content in the 24-hour period following glycogen-depleting exercise. * Denotes significantly lower value than glucose, maltodextrin, and waxy starch.
  • A high glycemic index rating does not necessarily indicate poor nutritional quality. For example, carrots, brown rice, and corn, with their rich quantities of health-protective micronutrients, phytochemicals, and dietary fiber, have relatively high indices.
  • General response of intestinal glucose absorption following feedings of foods with (A) low glycemic index and (B) high glycemic index. The low glycemic index food absorbs at a slower rate throughout the full length of the small intestine to produce a more gradual rise in blood glucose.
  • Glycemic index categorization of common food sources of carbohydrates.
  • Maintaining a relatively large stomach fluid volume throughout exercise enhances gastric emptying.
  • Major factors that affect gastric emptying and fluid absorption.
  • Regularly ingesting 150 to 250 mL of fluid throughout exercise continually replenishes fluid passed into the intestine; this maintains a relatively large and constant gastric volume.
  • Consuming this solution in recovery from prolonged exercise in a warm environment also improves endurance capacity for subsequent exercise.
  • Fluid volume to ingest each hour to obtain noted amount of carbohydrate.
  • Overall, available research does not support the popular notion that reducing carbohydrate while increasing fat intake above a 30% level optimizes the metabolic “zone” for endurance performance.
  • Section+5+eating+for+training+and+competition

    1. 1. Section 5Eating For Training and Competition
    2. 2. The Optimal Diet (in general and forphysical activity) Supplies required nutrients in adequate amounts for tissue maintenance, repair, and growth without excess energy intake Proper nutrition helps: • Improve athletic performance • Optimize programs of physical conditioning • Improve recovery from fatigue • Avoid injury
    3. 3. Energy Balance Equation Body mass remains constant when caloric intake equals caloric expenditure. 3500 kCal approximately equals 1 lb of stored body fat. Consume 3500 extra kCal, gain 1 pound Burn 3500 kCal, lose 1 pound
    4. 4. Principles of Good Eating  Variety • Choosing foods from a variety of sources creates a diet that contains sufficient amounts of all required nutrients.  Balance • Balance in one’s diet indicates the intake of nutrients from the major food groups.  Moderation • Eating moderately requires appropriate planning to maintain a balanced nutrient intake throughout the day.
    5. 5. MyPyramid www.mypyramid.gov Can be personalized based on age, sex, and level of daily exercise Includes a figure walking up the side of the pyramid to emphasize at least 30 minutes of moderate to vigorous daily physical activity Based on the 2005 Dietary Guidelines for Americans
    6. 6. Dietary Guidelines for Americans Control caloric intake to manage body weight. Consume a variety of foods. • Within the basic food groups Increase daily intake of fruits, vegetables, whole grains, beans, and nonfat or low-fat milk and milk products. Choose fats wisely for good health. • Limit saturated fats and trans fats. • Choose fish or plant-based fats.
    7. 7. Dietary Guidelines for Americans (cont.) Choose carbohydrates wisely for good health. Choose and prepare foods with little salt. If you drink alcoholic beverages, do so in moderation. Be physically active every day. Keep food safe to eat.
    8. 8. Serving Size Versus Portions The USDA defines a standard serving of pasta as one-half cup. The FDA, which regulates food labels, claims a standard serving is 1 cup. Typical restaurant pasta portion averages about 3 cups. • Equal to 6 servings according to MyPyramid
    9. 9. Mediterranean and Vegetarian DietPyramids Mediterranean • Emphasizes fruits, nuts, vegetables, legumes, all manner of unrefined grains, and protein derived from fish, beans, and chicken • High monounsaturated fatty acid content Vegetarian • Consists of foods from the plant kingdom
    10. 10. Protein Intake among the Physically Active RDA = 0.8 g/kg of body mass Eating a high-carbohydrate diet with adequate energy intake conserves muscle protein in individuals who engage in protracted intense training. -Sedentary but healthy individuals: 0.8 g of protein per kg of body weight ie: 125 lbs = 70 kg – needs 56 g of protein liberal allowance -Physically active individuals: 1.0 g/kg BW -Typical athletes: 1.0-1.2 g/kg -Endurance athletes and strength athletes: 1.2-1.5 g/kg ”Heartily sufficient reserve” This level is within the range of typical intakes for athletes *obviates the need for supplementary proteins
    11. 11. Protein Supplements Some athletes supplement with simple amino acids. Advocates believe the body absorbs the simple amino acid molecule more readily. The healthy intestine absorbs amino acids rapidly when they exist in more complex di- and tripeptide molecules, not just in simple amino acid form.*may lessen the immunological (and cortisol) mediated breakdown of tissue immediately after exercise
    12. 12. Vegetarian Athletes: Increasing numbers of athletes consume diets consisting predominately of nutrient from plant sources, and some dairy and meat products. -Carl Lewis: 9 Olympic gold medals in track and field -Dave Scott: 4 time World Iron Man Triathlete -Sean Yates: professional cyclist -Murray Rose: 4 Olympic god medals in swimming -Billie Jean King: professional tennis player -Martina Navratilova: professional tennis player -Bill Manetti: powerlifting champion -Bill Pearl: 4 time “Mr. Universe” bodybuilder
    13. 13. Lipid Intake among the Physically Active To promote good health, lipid intake should probably not exceed 30% of the diet’s energy content. • Of this, at least 70% should come from unsaturated fatty acids. Significant reductions in dietary lipid compromise exercise performance. Lipids are necessary to obtain essential fatty acids and fat-soluble vitamins.
    14. 14. Carbohydrate Intake among thePhysically Active Yeah, this is the most important macronutrient A low-carbohydrate diet rapidly compromises energy reserves for vigorous physical activity or regular training. Physically active individuals should consume at least 55- 65% of calories as carbohydrates, predominantly starches from fiber-rich, unprocessed grains, fruits, and vegetables. Endurance training = 10 g of carbohydrate per kg of body mass per day
    15. 15. Vitamin-Mineral Deficiencies Most often occur in: • Vegetarians or groups with low energy intake • Those who eliminate one or more food groups from their diet • Individuals who consume large amounts of processed foods and simple sugars with low micronutrient density
    16. 16. Vitamin Supplements 50 years of research fail to support the use of vitamin supplements to improve aerobic and anaerobic exercise performance. Maybe C? Daily supplements of 500-1500 mg of vitamin C per day may confer some benefit to individuals engaged in strenuous exercise who experience frequent viral infections.  RDA is 60 mg  120 mg is the most you can absorb in 24 hours
    17. 17. Be careful of consuming Megavitamins  Contain doses at least 10 and up to 1000 times the  Folate = trigger an allergic RDA response  Excess vitamin C = kidney  Excess vitamin E = headache, fatigue, blurred vision, stones gastrointestinal disturbances,  Excess vitamin B6 = liver muscular weakness, and low blood sugar disease and nerve damage  Excess vitamin A = toxic to  Excess riboflavin (B2) = the nervous system impaired vision  Excess vitamin D = damages  Excess niacin = vasodilation kidneys and inhibition of fatty acid mobilization during exercise
    18. 18. Antioxidants Aerobic exercise metabolism increases the production of free radicals. Dietary Antioxidants help prevent: • ß-Carotene • Vitamin C • Vitamin E • Selenium, copper, manganese, and zinc • Coenzyme Q10 • BUT! Dietary antioxidants suppress endogenous antioxidant production • Glutathione peroxidase • Superoxide dismutase • Alpha lipoic acid • Catalase • Uric Acid (blood)
    19. 19. Antioxidants (the rest of the story) Antioxidant Supplements Blunt Exercise-Induced Improvement of Insulin Sensitivity Comment: Surprisingly, use of antioxidant supplements blunts the beneficial effects of regular exercise… Overall, little evidence of benefit from regular use of vitamin C or E supplements exists, and this study offers one reason to discourage their use and to encourage diets that are rich in fruits and vegetables. - Anthony L. Komaroff, MD Moderation….
    20. 20. Minerals Excessive sweating during exercise causes loss of body water and related minerals. Mineral loss should be replaced following exercise through well-balanced meals. Single-mineral supplementation is ill advised unless prescribed because of potential adverse consequences.
    21. 21. Exercise and Food Intake Energy intake needs to be balanced with energy expenditure. Individuals who engage regularly in moderate-to- intense physical activity eventually increase daily energy intake to match their higher level of energy expenditure. Many athletes, particularly females, do not meet energy intake recommendations.
    22. 22. Eating for Competition:• Pre-competition• During competition• After competition*Training sessions too Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
    23. 23. The Precompetition Meal Readily digestible foods Should contribute to energy and fluid requirements Meals high in carbohydrates and relatively low in lipids and proteins Three to four hours to digest and absorb the precompetition meal *Carbs before and during – Protein and carbs after
    24. 24. Ideal Precompetition Meal The ideal precompetition meal: • Contains 150 to 300 grams of carbohydrates • Is consumed 3 to 4 hours before the event • Contains little fat • Contains little fiber
    25. 25. Liquid Meals High carbohydrate content Supply fluids Digest rapidly Can be used for day-long events Supplement calorie intake in those with difficulty maintaining body weight
    26. 26. Nutrition Bars High protein content Approximately 25 g of carbohydrate Often include vitamins and minerals May contain dietary supplements Should not substitute for normal food intake
    27. 27. Nutrition Powders and Drinks High protein content Contain vitamins, minerals, and other dietary supplements Come in powdered form or premixed Contain fewer calories per serving than nutrition bars
    28. 28. Carbohydrates before Exercise If simple sugars are consumed, they should be consumed at least 60 minutes before exercising. • This time gives hormones the chance to rebalance. Fructose absorbs more slowly compared to glucose or sucrose. • High-fructose beverages can produce significant gastrointestinal distress.
    29. 29. Carbohydrates during Exercise Allows for a greater intensity during prolonged activities Consuming about 60 g of liquid or solid carbohydrates each hour benefits: • High-intensity, long-duration aerobic exercise • Repetitive short bouts of near-maximal effort Spares muscle glycogen Helps maintain a more optimal blood glucose level
    30. 30. Carbohydrates after Exercise High-glycemic carbohydrate-rich foods Either a single large meal or small frequent meals will replenish glycogen stores. Should be consumed as soon as possible after the activity Avoid legumes, fructose, and milk products.
    31. 31. Glycemic Index Indicates how a carbohydrate-containing food affects blood glucose levels High-glycemic index Moderate-glycemic index Low-glycemic index Affected by food preparation, ripeness, and how foods are combined
    32. 32. Glycogen Depletion High-intensity aerobic exercise for 1 hour decreases liver glycogen by about 55%. A 2-hour strenuous workout nearly depletes the glycogen content of the liver and specifically exercised muscles.
    33. 33. Hydration Solutions Carbohydrate-containing solutions consumed during exercise enhance endurance performance by maintaining blood sugar concentration. Glucose supplied in the blood can: • Spare existing glycogen in active muscles • Serve as “reserve” blood glucose for later use should muscle glycogen become depleted
    34. 34. Oral Rehydration Solutions Provide additional glucose Minimize the effects of dehydration on: • Cardiovascular dynamics • Temperature regulation • Exercise performance Adding electrolytes aids in: • Maintaining thirst mechanism • Reducing the risk of hyponatremia
    35. 35. Carbohydrate-Electrolyte Beverages The ideal hydration solution contains between 5% and 8% carbohydrates. This permits carbohydrate replenishment without adversely affecting fluid balance and thermoregulation. Maintains glucose metabolism and preserves glycogen during prolonged exercise
    36. 36. Hydration during Exercise Adding moderate amounts of sodium to the ingested fluid helps to maintain plasma sodium concentration. This benefits the ultra-endurance athlete at risk for hyponatremia. Maintaining plasma osmolality with added sodium in the hydration beverage reduces urine output and sustains the sodium-dependent osmotic drive to drink.
    37. 37. High-Fat Diets Conflicting research findings Detrimental health risks are possible. Heath risks may not apply to athletes. Significant restrictions in fat impair exercise endurance.

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