NSCA运动与营养指南TrueSport-Nutrition-Guide.pdf

TrueSport Nutrition GuideOptimal Dietary Intakethe Basics.For Sport.For Life.Powered by the U.S.Anti-Doping Agency(USADA)NutritioNal requiremeNts of athletes1TrueSporT nuTriTion guideNutritioNal requiremeNts of athletescontentsCarbohydrates The Master Fuel Page 2proteins role as a Team player Page 12dietary Fat Page 16Vitamins and Minerals Page 18Fluids and Hydration Page 24resources Page 28THe purpoSe oF THiS book This publication provides general guidelines to help optimize dietary intake for sports competitors.Dietary intake requirements can vary depending upon an individuals energy expenditure,metabolism,state of health,etc.Now more than ever,athletes need accurate sports nutrition information.Optimal nutrition is an integral part of peak performance while an inadequate diet and lack of fuel can limit an athletes potential for maximum performance.Unfortunately,there is a lot of misinformation available regarding a proper diet for athletes.In the quest for success,many athletes will try any dietary regimen or nutritional supplementation promising a new level of physical performance.However,most often an evaluation and modification of current dietary intake can be employed to help maximize peak performance.The human body must be supplied continuously with energy to perform its many complex functions.As an athletes training and competition level increases,the bodys energy demands also increase.Several energy systems in the body can provide athletes with fuel as long as they are consuming the proper foods.One energy system relies totally on carbohydrates while another uses carbohydrates as well as fats.When an athlete works near or at maximal intensities,carbohydrates are the prime fuel the body can use.During prolonged exercise such as cycling,triathlons,and long-distance swimming,the amounts of fats and carbohydrates used may rise and fall depending upon:F Duration and intensity of the exerciseF An individuals fitness level F Food and drink consumed prior to and during the exercise32TrUeSPOrT NUTrITION gUIDeTrueSporT nuTriTion guideNutritioNal requiremeNts of athletesCarbohydrates The Master FuelA diet rich in carbohydrates increases endurance performance because of the extra store of carbohydrates in the muscles and liver,called glycogen.Work completed in the early 1980s by David Costill at Ball State University showed that if athletes did not consume a diet high in carbohydrates on a daily basis,they would experience chronic fatigue and poor performance.It is well documented that endurance athletes need to replenish carbohydrate stores in the body,especially during periods of intense training.Consuming carbohydrates during workouts lasting over one hour can also benefit performance and delay onset of fatigue.Several recent studies have shown that athletes who participate in stop-and-go sports,such as basketball and soccer,may also need to focus on consuming more carbohydrates during training and competition.This is not surprising since it is well-known that carbohydrates,when compared to protein and dietary fat,are the most efficiently broken down and metabolized form of energy for the body.Athletes doing stop-and-go activities were found to have better speeds and delayed fatigue when consuming a higher carbohydrate diet.reCoMMended inTAke oF CArboHydrATeS Depending upon the training routine,athletes should consume at least 50 percent,but ideally 60-70 percent of their total calories from carbohydrates.This percentage is only a guideline for estimating carbohydrate needs.Depending upon the length of training sessions,an athletes carbohydrate intake should be between 2.5-6.0 grams per pound of body weight,with longer training times reflecting the higher number of grams needed.See Table 1 to calculate grams of carbohydrates needed.CArboHydrATe inTAke beFore,during,And AFTer exerCiSe Before Exercise:The pre-exercise or pre-training meal serves two purposes:F It keeps the athlete from feeling hungry before and during exercise,andF It maintains optimal levels of energy for the exercising muscles.Athletes who train early in the morning,before eating or drinking,risk developing low blood glucose levels,as well as a poor performance,due to a decreased ability to concentrate and an increased perceived exertion.Blood glucose,the sugar found in the blood,is the energy delivered to the working muscles and organs that allows your body to complete activity.Low blood glucose levels cause you to feel more sluggish than normal and decrease your ability to focus,which inevitably will decrease performance.FYI(Focus on Your Intake)AS eArly AS THe 1930S,SCienTiSTS obSerVed THAT endurAnCe exerCiSe Could be iMproVed by inCreASing CArboHydrATeS in THe dieT.TaBlE 1:DETErMining graMs oF carBohyDraTE For aThlETEs nEEDsThe following example shows how to calculate the recommended grams of carbohydrate needed per pound of body weight.Weight in Pounds Carbohydrates in grams Daily Carbohydrate Intake 160 x 2.5=400 gramsNow calculate your own needs.Remember to multiply your body weight by a higher number of carbohydrate grams for lengthier or multiple bouts of training.For example,an hour of training per day may indicate using 2.5 grams in your calculation,and training four or more hours per day may indicate using 6.0 grams.Weight in Pounds Carbohydrates in grams Daily Carbohydrate Intake x =54TrUeSPOrT NUTrITION gUIDeTrueSporT nuTriTion guideNutritioNal requiremeNts of athletesCarbohydrate intake before exercise can help to restore sub-optimal glycogen stores,which is critical for prolonged periods of exercise.While allowing for personal preferences and psychological factors,the pre-event meal should be high in carbohydrates,non-greasy,and readily digestible.Fatty foods should be limited as they delay the emptying time of the stomach and take longer to digest.The following are guidelines for the pre-event meal:F The meal should be eaten 3-4 hours before an event.F It should provide 150-350 grams of carbohydrates(1.5 grams per pound of body weight).F To avoid stomach upset,the carbohydrate content of meals should be reduced the closer the meals are to the event.F Adding small amounts of protein can aid in regulating energy levels by slowing down carbohydrate absorption,delivering the carbohydrates to the working muscles at a more consistent rate over time.F Pay attention to salty cravings.If competing in hot/humid climates,make sure to replace electrolyte losses with salty snack foods,such as pretzels or sport drinks with added sodium.For example,four hours before the event,it is suggested that the athlete consume 1.5 grams of carbohydrates per pound of body weight,whereas one hour before the competition,the athlete would consume 0.5 grams of carbohydrates per pound of body weight.table 2:suggEsTED MEals For prE-EvEnT EaTingThis example shows how to calculate the recommended grams of carbohydrate needed per pound of body weight.1 Hour or Less Serving Size Grams of Carbohydrates Food bar 1 bar 47 g raisins small box(2.5 oz)34 g Banana 7 oz 31 g 1/2 Bagel 2 oz 26 g Pretzels 20 pieces 22 g Fig bar(2)1 oz 20 g Applesauce 4 oz 14 g Sports drink*8 oz 14 g Toast 1 slice 14 g Crackers 5 crackers 10 g 2-3 Hours before Serving size Grams of carbohydrates Baked potato(plain)1 large 58 g Cereal(whole grain)/cereal:1 cup cereal:47 g low-fat milk(1%)milk:1/2 cup milk:8 g Bagel(whole grain)1 bagel bagel:47 g with peanut butter 2 tbsp peanut butter peanut butter:8 g Fruit smoothie 12 fl oz 47 g Food bar 1 bar 43 g (oatmeal raisin walnut)Oatmeal(instant)/oatmeal:1 cup oatmeal:26 g low-fat milk(1%)milk:1/2 cup milk:8 g Yogurt(nonfat)1 cup 33 g Pancakes/waffles 2 pancakes 20 g (from mix)(5”diameter)Fresh fruit(chopped apple)1 cup 19 g 4 or more Hours before Serving size Grams of carbohydrates Spaghetti with meat sauce 2-3 cups 75-100 g Pasta/pasta:1 cup pasta:60 g Chicken/chicken:4 oz chicken:0 g Vegetables vegetables:1 cup vegetables:6 g grilled chicken/chicken:3 oz chicken:0 g rice(white)/rice:6 oz rice:44.4 g fruit(chopped apple)fruit:1 cup fruit:19 g granola bar 1 bar bar:43 g (oatmeal raisin walnut)/sports drink*drink:8 oz drink:14 g Liquid meal replacement 1 can(11 fl oz)40 g Fruit juice 6 oz 18 g Turkey sandwich turkey:1 slice turkey:0 g (w/3 slices deli meat,mayo:1 tbsp mayo:0 g 2 slices whole wheat bread,bread:2 slices bread:12 g low-fat mayo)/baby carrots 7 carrots carrots:3 g Tuna sandwich tuna:2 oz drained tuna:0 g (2 slices whole wheat bread)/bread:2 slices bread:24 g nonfat mayo mayo:1 tbsp mayo:0 g Trail mix with nuts/raisins 1/3 cup 20 gtable 2:suggEsTED MEals For prE-EvEnT EaTing,conTinuED*remember that sports drinks are beverages that contain electrolytes and carbohydrates,not caffeine and other stimulants.For more information on sports drinks and hydration,read the Fluids and Hydration section on page 22.76TrUeSPOrT NUTrITION gUIDeTrueSporT nuTriTion guideNutritioNal requiremeNts of athletesEating at all-Day Events:It is important that athletes eat after competing to make sure that they will have enough energy in their muscles for the next race or competition,whether it be in the same day or the following days.The same dietary intake principles used to plan the pre-exercise meal can also apply to foods eaten at all-day events.If an athlete races at 10:00 a.m.and again after two hours,foods that are high in protein and fat will more than likely still be in the stomach potentially causing stomach or gastrointestinal(gI)distress.The following guidelines have been recommended to help athletes make wise food choices at all-day events.one hour or less between events or heats:F Stick with carbohydrates that are in liquid form,such as sports drinks.F If something solid needs to be eaten,try fruits like oranges,watermelon,cantaloupe,peaches,pears,applesauce,or bananas.These foods consist of mostly carbohydrates and water.They are digested very fast and therefore,will not cause as much of a problem with stomach cramping or gI distress.Another key point to making food choices with limited time between events,is limiting the quantity of the food eaten.The more an athlete eats,the longer it will take to digest,especially with any pre-competition nerves or stress.Two to three hours between events or heats:F Solid foods in the form of carbohydrates can be eaten,as there is enough time to digest them before competition.F Try eating bagels,hot or cold cereal with nonfat milk,or english muffins along with fruit like bananas,apples,oranges,peaches,or pears.F Be sure to drink plenty of fluids,like water or a sports drink,for hydration,electrolyte replacement,and restoration of glycogen stores.Avoid drinks that contain caffeine,carbonation and other stimulants.Four or more hours between events or heats:With four or more hours between events or heats,an athlete may want a meal,which should be composed primarily of carbohydrates.Keep the meals simple.The following meal examples for this situation are appropriate:F A turkey sandwich on two slices of whole wheat bread,low-fat yogurt with fruit,and water or a sports(fluid replacement)drink;or F Spaghetti with lean meatballs,bread,salad with low-fat dressing,and water or a sports(fluid replacement)drink.If there is a certain meal pattern before competition that an athlete thinks is a winning combination,then they should stick to it.Athletes who make food choices at concession stands need to know how to make the best choices.Most concession stands are filled with high-fat,high-calorie foods that are not designed to maximize performance.It is always wiser for athletes to pack a cooler from home with winning combinations,than to rely on the food at a concession stand.Table 3 has a list of nutrient-dense foods that are easy to pack in a cooler and will help supply energy throughout the day.During Exercise:Consuming carbohydrates during exercise lasting longer than 60 minutes ensures that the muscles receive adequate amounts of energy,especially during the later stages of the competition or workout.This has also been found to improve performance.The form of carbohydrates consumed does matter.Some athletes prefer to use a sports drink,whereas others prefer to eat solid or gel forms of carbohydrates.Use the following guidelines when consuming sports drinks with carbohydrates.F Consume 6 to 12 ounces of a sports drink with 6-8%carbohydrate concentration every 15-30 minutes during exercise(see Table 4).One gulp is about 2 ounces.F Water is needed to aid in absorption of the carbohydrate.Drinks with a concentration greater than 10 percent are often associated with abdominal cramps,nausea,and diarrhea.F For high intensity activities,sports drinks and gels containing multiple forms of sugar can increase absorption and delivery of carbohydrates.Note:Sports drinks should not be confused with“energy”drinks.“energy”drinks typically contain one or more stimulants and their carbohydrate concentration is usually greater than 10%.*Sports drinks are beverages that contain electrolytes and carbohydrates,not caffeine and other stimulants.table 3:coolEr FuElErs Food Serving Size Fat Carbohydrates Protein Baby carrots 7 carrots 0 g 3 g 0 g Breadsticks 1 stick(2 oz)6 g 24 g 4 g Celery 1 large stalk 0 g 2 g 0 g Cherry tomatoes 1/2 cup 0 g 7 g 1 g Chocolate milk(lowfat)1 cup 2 g 26 g 8 g Cottage cheese(lowfat)1/2 cup 1 g 3 g 14 g Dried fruit 1 package 1 g 188 g 7 g Sports drink*8 oz 0 g 14 g 0 g granola bar 1 bar 5 g 43 g 10 g (oatmeal raisin walnut)Fresh fruit 1 piece or 1 cup 1 g 19 g.3 g ginger snaps 1 oz 3 g 22 g 2 g Hummus 1/4 cup 5 g 13 g 3 g Meal replacement drinks 1 can(11 fl oz)3 g 40 g 10 g Nuts(mixed)1/4 cup 15 g 7 g 5 g Peanut butter 2 tbsp 16 g 7 g 8 g Pita bread 1 pita 2 g 35 g 6 g (whole wheat large pita)Turkey sandwich turkey:1 slice turkey:turkey:turkey:(3 slices deli meat,1 g per slice 0 g per slice 5 g per slice low-fat mayo,mayo:1 tbsp mayo:5 g mayo:0 g mayo:0 g 2 slices whole bread:1 slice bread:bread:bread:wheat bread)/5 g 24 g 2 g baby carrots 7 carrots carrots:0 g carrots:3 g carrots:1 g Vanilla wafers 4 wafers 10 g 19 g 1 g Whole grain bagel 1 bagel(4 oz)1.5 g 47 g 11 g Whole grain cereal 1 cup 1 g 47 g 7 g Whole grain crackers 5 crackers 15 g 11 g 1 g Yogurt(nonfat)8 oz 0 g 15 g 11 gFYI(Focus on Your Intake)It is best not to try different and new foods before an important competition.If an athlete is complaining of GI distress or stomach cramping,he or she should try different foods or use these guidelines.Athletes should keep a food log in addition to their training log.They should track what theyre eating before,during,and after training and how it affects their performance,both mentally and physically.8TrUeSPOrT NUTrITION gUIDeNutritioNal requiremeNts of athletesTrueSporT nuTriTion guide911TrueSporT nuTriTion guideNutritioNal requiremeNts of athletestable 4:calculaTing carBohyDraTE concEnTraTions in BEvEragEsTo assess the concentration of a fluid replacement drink or any beverage,use the following calculations:Amou