Nutrition for Athletes - Commonwealth Games Federation

athletes’ medical informationNutrition forAthletesA practical guide to eating forhealth and performancePrepared by the NutritionWorking Group of the InternationalOlympic CommitteeRevised and updated inFebruary 2010

athletes’ medical informationMessage fromAtul SinghAt the outset let me first welcomeall the participants and delegatesfrom across the world to NewDelhi and India — a land of richand diverse culture, more than5,000 years old. Your participation in theXIX Commonwealth Games is a tribute toyour competitive spirit and your commitmentto bringing people closer to each otherthrough sports.Staying committed to a balanced nutritionaldiet is key to achieving peak-level athletic performance.Aware of this, The Coca-Cola Companyand the International Olympic Committee (IOC)have partnered to put together this bookletcontaining nutrition advice for athletes. It hasinformation that will help athletes to makeinformed choices to meet their nutritional needsin different situations. It is no substitute forindividual advice from a qualified professionalbut tries to give practical information that willbe of use to athletes.The Coca-Cola Company has a rich heritageof supporting sports and physical activity. Weare proud partners to the Summer annd WinterOlympic Games, the Paralympics and FIFAWorld Cup Football, etc. We encouragesports at all levels, from youth developmentactivities to intense competitive sporting eventsat the international level. We are alreadysupporting several such programs in India. Infact, globally, the Company has now committeditself to have at least one physical activityprogram in every country in which it operates,by 2015.On behalf of the entire Coca-Cola systemin India, we wish you the very best as youcompete and establish friendships with peoplefrom other cultures and countries who shareyour passion for sports, friendship and goodwill.Atul SinghPresident,Coca-Cola India2

Foreword byDr M Jegathesanathletes’ medical informationIt is indeed a great privilege forme to pen a foreword to thishandy booklet on nutrition forathletes. The CommonwealthGames Federation (CGF) and itsMedical Commission have always placed greatemphasis on the value and importance of soundnutrition for athletes. The CGF also appreciatesthe efforts of the IOC in producing this booklet.This publication has been circulated widely andhas gained acceptance as a simple but effectivehandbook for athletes. This booklet underscoresthe strong conviction of the IOC and the CGFthat proper nutrition, applied with the help ofappropriate experts, is a viable alternative tothe scourge of doping in sports. Athletes needto be aware of the value of good nutrition, andit is our duty as sports physicians and sportsnutritionists to provide the necessary support.It is clear that the sports nutritionist will playan ever-increasing role in the care, training andpreparation for competition of elite athletes.This booklet will stimulate athletes to want toknow more of the impact of nutrition in theirdaily lives as well as on their thrust to greatersporting heights.Tan Sri Dr M JegathesanHonorary Medical Advisor,Commonwealth Games Federation3

athletes’ medical informationThe Games environmentThe 2010 Commonwealth Games are thenineteenth celebration of sporting competitionbetween nations of the Commonwealth and theninth to be held under that name. The openingceremony will take place at the JawaharlalNehru Stadium, Delhi. Competitions in 17different sports will be held in New Delhi, India,between 4 October and 13 October 2010,with the Closing Ceremony taking place on14 October.A state-of-the-art Games Village for useby athletes, support staff and team officials isbeing developed along the east bank of theRiver Yamuna by the Delhi DevelopmentAuthority, an agency of the Government of Delhiand a Commonwealth Games delivery partner.The site is located off the National Highway 24adjacent to the Akshardham Temple at theNoida intersection. Construction work on theGames Village started in August 2007 and is onschedule for completion by March 2010. TheVillage is designed to translate traditional Indianhospitality into standards of comfort andexcellence never seen before by participatingteams. To be created at a cost of more thanUS$230 million (including the Residential Zone),the Games Village is spread over an area of63.5 hectares (158 acres). It has 14 blocks,34 towers and 1,168 air-conditioned flats tocomfortably accommodate 8,000 athletesand team officials. There will be a number ofapartment types ranging from two- to fivebedroomunits, each with ensuite facilities.The residential facilities are expected to bethe best provided for any Games.Apart from living accommodations, theGames Village will contain training areas forAthletics (400 m eight-lane synthetic track andseparate area for Throwing events); Swimming(50x25m, kids and leisure pool); Weightlifting;Wrestling; and a Fitness Centre. Temporarystructures will house the International Zone,Village Operation and Support Areas.World-class stadia will house competitorsin 17 sports: Archery, Aquatics, Athletics,Badminton, Boxing, Cycling, Gymnastics,Hockey, Lawn Bowls, Netball, Rugby 7s,Shooting, Squash, Table Tennis, Tennis,Weightlifting and Wrestling. In addition, 15events will be contested across 4 Para-Sports,for elite athletes with a disability, on theinclusive Sports Programme: Athletics,Swimming, Powerlifting and Table Tennis.The weather in India can be challenging,especially for newcomers to the country. Theaverage daily temperature high in New Delhiduring the period of the Games is about 33°Cand the average daily low is about 20°C. Thetemperature may, however, be much higherthan this — it was over 40°C for several daysduring this time period in 2007. It is unlikely tofall to less than about 18°C at any time duringthis period. Full records for humidity are notavailable, but the humidity is generally high —often in the region of 80%, especially later inthe day. Rainfall is generally light. These arechallenging conditions for athletes from highlatitudes who are used to much cooler anddrier climates.Where athletic competitions are scheduledfor hot weather venues, there is a need for allathletes to prepare for the conditions that willbe encountered. This is especially true for thoseathletes who normally live, train and compete in4

athletes’ medical informationcool climates. There are three aspects ofpreparation for these conditions: first, thedevelopment of a suitable rehydration regimen,and, second, the development of anacclimatisation strategy. The third issue relatesto the pre-event warmup, for warming up maynot always be beneficial. For athletes whohabitually live and train in cool climates, thereare few opportunities to rehearse thesepreparations, but they are essential if there isto be any chance of success.It is also important that athletes reassesstheir idea of what ‘hot’ actually means. Inendurance events, performance already sufferswhen the temperature reaches 20°C and islikely to be at its best at about 10°C. Fewathletes would think that a temperature of 20°Cis enough to start thinking about drinks andother issues associated with hot weatherrunning. Over shorter distances, the optimumtemperature for competition is likely to behigher, but too much time spent in a warm sunmay be harmful even in the sprints.All athletes should take advantage ofopportunities to gain experience of living,training and competing in hot environmentsbefore the Games. Each athlete should havea personal strategy that fits within the team’shot weather strategy.5

athletes’ medical informationKey messagesWhenever highly talented, motivated andwell-trained athletes gather for competition, themargin between victory and defeat is small.Attention to detail can make that vital difference.Diet affects performance, and the foods thatwe choose in training and competition will affecthow well we train and compete. Athletes needto be aware of their nutritional goals and ofhow they can select an eating strategy to meetthose goals.Diet may have its biggest impact on training,and a good diet will help support consistentintensive training without the athletesuccumbing to illness or injury. Good foodchoices can also promote adaptations to thetraining stimulus.Athletes are all different, and there is nosingle diet that meets the needs of all athletesat all times. Individual needs also change acrossthe season and athletes must be flexible toaccommodate this.Getting the right amount of energy to stayhealthy and to perform well is key. Too muchand body fat increases: too little andperformance falls and illness results.Carbohydrate is a key nutrient for energysupply. Athletes must be aware of foods thatcan help meet their carbohydrate needs andmake these a focus of their diet.Protein foods are important for building andrepairing muscles, but a varied diet containingeveryday foods will generally supply more thanenough protein. Well-chosen vegetarian dietscan also meet protein needs.A varied and wholesome nutrient-rich dietthat meets energy needs and is based largelyon vegetables, fruits, beans, legumes, grains,animal meats, oils and carbohydrate shouldensure an adequate intake of vitamins andminerals.Maintaining hydration is important forperformance. Fluid intake before, during (whereappropriate) and after exercise is especiallyimportant in hot climates. Salt replacement isimportant when sweat losses are high.Athletes are cautioned against theindiscriminate use of dietary supplements.This booklet contains information that willhelp athletes to make informed choices tomeet their nutritional needs in differentsituations. It is no substitute for individualadvice from a qualified professional buttries to give practical information that willbe of use to the serious athlete.6

The benefitsof eating wellathletes’ medical informationA well-chosen diet offers many benefitsto the elite athlete:• Fuel to train and perform at the elite level• Optimal gains from the training program• Enhanced recovery between workouts andbetween events• Achievement and maintenance of an idealbody weight and physique• Benefits from the many health-promotingcomponents of food without the requirementfor supplements• A reduced risk of injury, overtraining fatigueand illness• Confidence in being well-prepared to facecompetition• Consistency in achieving high-levelcompetition performances• Enjoyment of food and social eating occasionsat home and during travelDespite these advantages, many athletesdo not meet their nutrition goals. Commonproblems and challenges include:• Poor knowledge of foods and inadequatecooking skills• Poor or outdated knowledge of sportsnutrition• Lack of access to dietitians /nutritionprofessionals or other credible resources• Inadequate finances• Busy lifestyle leading inadequate timeto obtain or consume appropriate foods• Poor availability of good food choices• Frequent travel• Indiscriminate use of large amounts ofsupplements and sports foodsThe information in this booklet is designed toprovide coaches and athletes with an overviewof the latest guidelines in sports nutrition. Whilethere is no such thing as a magic diet or food,there are many ways in which eating well canallow athletes at all levels of performance toachieve the specific goals of their training andcompetition programs. It makes no sense totrain hard and ignore the benefits that followfrom good food choices.This booklet is based on the conclusions ofthe IOC Consensus Conference on Nutritionfor Sport, held in Lausanne in June 2003.It was first produced for the 2004 OlympicGames and was revised for the Gamesof 2006, 2008 and 2010. We gratefullyacknowledge the contribution of theconference participants as the expertscientific sources for this booklet. We arealso especially grateful to Powerade fortheir support.The information in this booklet wasextensively revised and updated in February2010 in preparation for the CommonwealthGames of 2010 to ensure that athletes haveaccess to the latest information.7

athletes’ medical informationEnergy needs fortraining and competitionAn athlete’s daily energy intake (total Calories orkilojoules) provides for immediate energy needssuch as that for body functions, activity andgrowth. In addition, energy intake alsoinfluences the body’s energy stores. Energystores (body fat + glycogen in muscle and liver)play a number of important roles related toexercise performance, since they contribute to:• an athlete’s size and physique (e.g., body fatstores and muscle mass)• function (e.g., muscle mass)• fuel for exercise (e.g., muscle and livercarbohydrate stores, i.e., glycogen)Many athletes try to manipulate energyintake to gain an advantage in their sport. Inmost cases, the goals are to change bodyweight, reduce body fat, increase musclemass and optimize fuel storage. Problems canoccur when:• the athlete is unable to identify goals that aresuitable for their sport and appropriate to theirindividual makeup• the athlete is unable to monitor the separatecomponents of their goals (for example, todistinguish changes in body fat from changesin total body weight, or to see whether totalenergy intake provides for optimal fuelstorage, i.e., muscle and liver glycogen)• the athlete restricts energy intake to a levelthat interferes with the body’s metabolic andhormonal functions (e.g., loss of themenstrual cycle in female athletes)Strategies for managing energy intake andenergy balance:Individualized assessment of an athlete’s bodyweight and body composition may be necessaryfor improved athletic performance. Age, sex,genetics and sport requirements are factorsthat affect an individual athlete’s bodycomposition.An optimal competitive body weight andrelative body fat level should be determinedwhen an athlete is healthy and performing athis or her best.Each athlete should individually managetheir energy stores of body fat, carbohydrate(muscle fuel) and protein (muscle mass) bymanaging intake and expenditure of thesenutrients separately. These issues will bediscussed in separate parts of this booklet.Athletes should eat to a plan that achievestheir specific goals rather than relying onappetite (which may be suppressed with intensetraining) or opportunity (overeating when food isabundant rather than planning ahead) to guideenergy intake. Advice from a sports nutritionexpert is often required to develop aneffective plan.The athlete should have a number ofseparate biomarkers to monitor their progressin achieving each of their energy-related goals.Body weight is not a reliable or accurateindicator of energy balance. Monitoring bodyweight is often a stressful activity for athletes,especially when the information ismisinterpreted or the outcome is manipulated.Long-term monitoring of skinfold fat8

athletes’ medical informationthicknesses, especially when undertaken by atrained kinanthropometrist, can provide usefulinformation about changes in body fat stores.Measurements of changes in muscle strengthand endurance provide a useful biomarker ofmuscle development.Special concerns about restrictingenergy intakeMany athletes reduce their energy intake toassist with the loss of body weight and body fat,but it is harmful to restrict energy intake belowlevels that interfere with healthy body function.Athletes requiring advice for weight loss orfat loss should seek guidance from a sportsnutrition expert such as a sports dietitian.To avoid irreversible skeletal damage,athletes with menstrual disorders shouldbe immediately referred to a medicalexpert for treatment.9

athletes’ medical informationFuel needs for trainingand recoveryCarbohydrate provides an important butrelatively short-lived supply of fuel for exercisethat must be refilled each day from carbohydratefoods in the diet. The athlete’s everyday eatingplan needs to provide enough carbohydrate tofuel their training program and to optimise therecovery of muscle glycogen stores (musclefuel) that are depleted during workouts. Generaltargets can be provided for carbohydrate needs,based on the athlete’s size and the demands oftheir training program (see Table below). However,actual needs are specific to the individual athleteand need to be fine-tuned with considerationof the athlete’s total energy needs, specifictraining needs and feedback from their trainingperformance. Carbohydrate intake should bescaled down or up according to the fuel needsof training or competition, and someconsideration given to arranging when it isconsumed around key workouts or competitionevents over the day to promote good fuelavailability for performance and recovery.Targets for carbohydrate intake• Immediate recovery after exercise(0-4 hours): about 1 g per kg of theathlete’s body weight (BW) per hour,perhaps consumed at frequent intervalsin the hours after exercise• Daily recovery from a moderateduration/low intensity training program:5-7 g per kg BW per day• Recovery from moderate-heavy endurancetraining: 7-12 g per kg BW per day• Daily recovery from extreme exerciseprogram (more than 4-6 h+ per day):10-12 g or more per kg BW per dayStrategies for choosing carbohydrate foodsand for optimising glycogen recoveryWhen the period between workouts is less thanabout 8 hours, carbohydrate intake should startas soon as practical (possible) after the firstsession to maximise the re-fuelling process.There may be some advantages in meetingcarbohydrate targets as a series of frequentsnacks during the early recovery phase.Consuming a high carbohydrate snack beforestretching or showering may improve theability to work intensely in the followingtraining session.During longer recovery periods (24 hours),the pattern and timing of carbohydrate-richmeals and snacks does not appear to becritical, and can be organised according to whatis practical and comfortable for each athlete.There is no difference in glycogen synthesiswhen carbohydrate is consumed in liquid formor as solid foods.It is valuable to choose nutrient-richcarbohydrates and to add other foods torecovery meals and snacks to provide a goodsource of protein and other nutrients. Thesenutrients may assist in other recoveryprocesses, and in the case of protein, maypromote additional glycogen recovery whencarbohydrate intake is below targets or whenfrequent snacking is not possible.Carbohydrate-rich foods with a moderateto high glycaemic index (GI) provide a readilyavailable source of carbohydrate for glycogensynthesis and should be the major fuel choicesin recovery meals. (See Table for examples.)10

athletes’ medical informationProtein needs for trainingand bulking upProtein has been considered a key nutrient forsporting success by athletes of all eras.Whereas ancient Olympians were reported toeat unusually large amounts of meat, today’sathletes are provided with a vast array of proteinand amino acid supplements to increase theirprotein intakes.Protein plays an important role in theresponse to exercise. Amino acids from proteinsform building blocks for the manufacture of newtissue, including muscle, and the repair ofdamaged tissue. They are also the buildingblocks for hormones and enzymes that regulatemetabolism, support the immune system andother body functions. Protein provides a smallsource of fuel for the exercising muscle.Some sports scientists have suggested thatendurance and resistance-training exercise mayincrease daily protein needs up to a maximumof 1.2-1.6 g per kg body weight (BW),compared to the recommended intake of0.8 g/kg BW for a sedentary person. However,the evidence for this increase in protein needsis not clear and universal. Part of the confusionis caused by problems involved in scientifictechniques used to measure proteinrequirements.The debate over protein needs of athletes islargely unnecessary. Dietary surveys show thatmost athletes already consume diets providingprotein intakes above 1.2-1.6 g/kg BW/d,even without the use of protein supplements.Therefore, most athletes do not need to beencouraged or educated to increase theirprotein intakes. Rather, athletes who consumeadequate total energy intake from a variety ofnutrient-rich foods should be confident ofmeeting their protein needs, including anyincreases that could arise from high-leveltraining.Athletes at risk of failing to meet theirprotein needs are those who severely restricttheir energy intake or dietary variety. Anadequate energy intake is also important inpromoting protein balance, increasing proteinretention (as lean tissue) as well as beingprotein (muscle) sparing.Some resistance-trained athletes and bodybuilders consume protein intake in excess of2-3 g/kg BW/d, but there is no evidence thatintakes of more than about 1.7 g/kg BW/d areever necessary to enhance the response totraining or increase the gains in muscle massand strength. While such diets are notnecessarily harmful, they are expensive and canfail to meet other nutritional goals, such asreplacing important fuel sources (carbohydrates)needed to optimise training and performance.Enhanced protein balance is a desirable goalof the recovery phase — to overturn theincreased rates of protein breakdown that occurduring and after exercise, and to promotemuscle hypertrophy, repair and adaptationfollowing the exercise stimulus. Recent studieshave focussed on the acute response toworkouts of both endurance and resistancetraining. These studies have found that theintake of protein, and perhaps the addition ofcarbohydrate, enhances protein synthesisduring the recovery phase after training. Thereis some evidence that the response is enhancedwhen these nutrients are provided soon afterexercise. Further work is required to fine-tuneguidelines for the optimum amount, type and12

athletes’ medical informationtiming of intake of these nutrients, and toconfirm that these eating strategies lead tobetter achievement of the goals of training.In the meantime, it appears sensible to focuson the total balance of the diet and the timingof protein-carbohydrate meals and snacks inrelation to training, rather than high proteinintakes per se. Frequent intake of smalleramounts of protein is most beneficial due tothe fact that protein is not stored in the body insignificant amounts; therefore, frequency ofingestion ensures protein needs are consistentlybeing met.Special sports foods such as sports bars andliquid meal supplements can provide a compactand convenient way to consume carbohydrateand protein when everyday foods areunavailable or are too bulky and impractical toconsume. There is little justification for usingvery expensive protein-only powders or aminoacid supplements, which are not superior inquality to foods, and also do not contain valuablenutrients that are found in protein foods.Protein-rich foods: 10 g of protein isprovided by• 2 small eggs• 300 ml cow’s milk• 20 g skim milk powder• 30 g cheese• 200 g yoghurt• 35-50 g meat, fish or chicken• 4 slices bread — 90 g breakfast cereal• 2 cups cooked pasta or 3 cups rice• 400 ml soy milk 60 g nuts or seeds• 120 g tofu or soy meat — 150 glegumes or lentils• 200 g baked beans — 150 mlfruit smoothie or liquid mealsupplement13

athletes’ medical informationVitamins, minerals andantioxidants for training andstaying wellStrenuous bouts of prolonged exercise andheavy training, particularly aerobic exercise,stress the body both physically and mentally.Adequate intakes of energy, protein, iron,copper, manganese, magnesium, selenium,sodium, zinc, and Vitamins A, C, E, B6 and B12are particularly important to health andperformance. These nutrients, as well as others,are best obtained from a varied and wholesomenutrient-rich diet based largely on vegetables,fruits, beans, legumes, grains, lean meats, dairyfoods and healthy oils. Dietary surveys showthat most athletes are well able to meet therecommended intakes for vitamins and mineralsby eating everyday foods.Those at risk of suboptimal intakes of thesemicronutrients include:• athletes who restrict their energy intake,especially over long periods, especially tomeet weight-loss goals• athletes who follow eating patterns withrestricted food variety and reliance on foodswith a poor nutrient-densityThe best way to correct this situation is to seekadvice from a sports nutrition expert such as asports dietitian. When food intake cannot beadequately improved — for example, when theathlete is travelling in a country with a limitedfood supply — or if an individual is found to besuffering from a lack of a particular vitamin ormineral, then short-term supplementation canbe warranted. This should be undertaken withthe advice of a qualified sports nutrition expert.In general, a broad-range multivitamin/mineralsupplement is the best choice to support arestricted food intake, although targetednutrient supplements may be necessary tocorrect an established nutrient deficiency(e.g., iron deficiency).Antioxidant nutrientsAntioxidant nutrients help the body neutralizeharmful oxidising products that may accumulateduring intense or prolonged training and potentiallydamage healthy tissues and impair properrecovery. It is not known whether hard trainingincreases the need for dietary antioxidants, asthe body naturally develops an effective defencewith a balanced diet. Supplementation withantioxidants cannot be recommended becausethere is little evidence of benefit, while it isknown that over-supplementation can diminish

athletes’ medical informationthe body’s natural defence system and maypossibly interrupt the body’s own adaptationto training. Antioxidants are safest and mosteffective when consumed in abundance asplant-derived foods from a wide variety ofsources (e.g., fruits, vegetables, nuts, seeds,whole grains, teas and non-medicinalherbs, etc.)Ideas for promoting dietary varietyand nutrient-rich eating• Be open to trying new foods andnew recipes• Make the most of foods in season• Explore all the varieties of differentfoods• Mix and match foods at meals• Think carefully before banishing a foodor group of foods from your eating plans• Find substitution foods that have similarnutrients when excluding a food group• Include fruits and/or vegetables at everymeal and snack. The strong and brightcolours of many fruits and vegetablesare a sign of a high content of variousvitamins and other food antioxidants.Aim to fill your plate with a rainbow ofhighly coloured foods to ensure a goodintake of the range of these healthpromotingdietary compounds.Special concernsIron. Some athletes may develop irondeficiency and this will impair performance.Unexplained fatigue, especially invegetarian athletes, should be explored.Routine use of iron supplements is notwise: too much is just as harmful as toolittle. Self-medication with ironsupplements may not address the realcauses of an athlete’s fatigue or otherissues of poor eating and may do moreharm than good. See page 25 for ironricheating strategies.Calcium. Calcium is important for healthybones, especially in adolescents and infemale athletes, so it is important toensure adequate calcium intake. The bestsources are dairy produce, includinglow-fat varieties. Each athlete should aimto include at least 3 servings of thesefoods in their daily eating plans (e.g.,glass of milk, slice of cheese, carton ofyoghurt). Additional daily servings arerequired during growth spurts in childhoodand adolescence, and for pregnancy andlactation. Fortified soy foods may providea useful substitute for athletes who cannotconsume dairy foods.15

athletes’ medical informationPreparation forcompetitionMany athletes appreciate the need to rest andeat well during the days prior to competition ora particularly intense day of quality training,but questions arise regarding how much to eat,what type of food and when is the best time.This includes what to eat during the few hoursimmediately before competition or intensetraining.Carbohydrate is the key energy-providingnutrient that must be optimised during thedays leading up to and including the day ofcompetition. Attention should also be givento optimising water and salt levels in thebody. However, during the 2-4 days prior to acompetition, an athlete’s need for protein andfat, as well as most other nutrients, typicallydoes not increase above the levels that arerecommended for normal moderate-leveltraining, especially as the training load istapered at this time.‘Carbo-loading’Athletes who compete intensely for more thanabout 90 minutes benefit from ‘carbohydrateloading’for a few days. This loading of muscleglycogen to super-compensated levels can beachieved within 1-3 days by eating a largeamount of carbohydrate (about 8-10 g CHOper kg of body weight per day; see below) atthe same time that training intensity is reducedto no more than easy levels of short duration.It is assumed that a moderate to hard boutof fatiguing exercise is performed in normaltraining sometime earlier in the week priorto competition.One-day example of foods providing 630 gof carbohydrate for a carbohydrateloadingdiet* (for a person weighing 70 kgwith an intake of 9 g CHO/kg BW).• Early AM: 150 g = 2 cups cereal withmilk + 250 ml fruit juice + 1 banana +2 thick slices toast + thick spread ofjam• Late AM: 50 g = 500 ml soft drink• Mid-day: 150 g = 1 large bread roll + 1medium muffin + fruit smoothie• Snack: 50 g = 200 g flavoured yoghurt+ 250 ml fruit juice• Dinner: 200 g = 3 cups cooked pasta +2 cups fruit salad + 2 scoops ice cream+ 500 ml sports drink• Snack: 30 g = 50 g chocolate ordried fruit(*Note that other foods may be eatenat the meal, such as moderate amountsof protein foods, but also keeping fatintake low.)Carbohydrate in the 6-hour period beforecompetitionAthletes sometimes find a favourite precompetitionmeal that not only provides extraenergy during the event but also feels right interms of curbing hunger, quieting their stomachand being convenient as well as practical. Insports that do not cause fatigue or carbohydratedepletion (e.g., gymnastics, sprinting,16

athletes’ medical informationski-jumping, etc., the pre-event meal need notbe predominantly carbohydrate. However, inintense competitions lasting longer than about60 minutes, athletes are advised to either:• Eat a meal or snacks providing 1-4 g/kg bodyweight of carbohydrate during the 6-hourperiod before exercise, or• Miss the pre-event meal, if preferred, but onlywhen a carbohydrate-loading diet has beenfollowed during the prior 2-3 days and thecompetition is not late in the day.The main ‘mistake’ athletes might makeis to eat only a small amount of carbohydrate(less than 1 g CHO/kg body weight) during the1-6 hour period before exercise and then failto consume any carbohydrate during exercise.This small carbohydrate meal primes the bodyto rely more heavily on blood glucose, but itdoes not provide enough carbohydrate tosustain the athlete.Five different examples of foods that eachprovide 140 g CHO in a pre-competitionmeal* (2 g/kg BW for a 70 kg person) are:• 2.5 cups breakfast cereal + milk +large banana• Large bread roll or 3 thick slices bread+ thick spread honey• 2 cups boiled rice + 2 slices bread• 4 stack pancakes + ½ cup syrup• 60 g sports bar + 500 ml liquid mealsupplement or fruit smoothie(*Note that other foods may be eatenat the meal.)Fluid intake prior to competitionAthletes should drink sufficient fluid withmeals on the day before competition toensure adequate hydration on the morning ofcompetition. The athlete should not refrain fromdrinking water or carbohydrate-containing fluidsduring the hours leading up to warm-up beforecompetition and it is recommended thatathletes have a final drink during the 60- to90-minute period before the start of the event.This will allow sufficient time for urination ofexcess fluid, and thus rest-room facilitiesshould be identified. During competitions lastinglonger than 1 hour and which cause heavysweating without sufficient opportunity for fluidintake, athletes often benefit by having an extradrink during the 15-minute period immediatelybefore the start of the event.17

athletes’ medical informationFluid, carbohydrate andsalt needs during andafter exerciseAthletes generally appreciate the need to drinkfluids during exercise and the importance ofsometimes using drinks that contain addedcarbohydrate and salts. The next step inapplying this theory for optimal performanceand well-being is to learn the practical aspectsof: a) how much, b) what type of foods, drinks,products, c) when during exercise, and d) whatmodifications should be made in hot or coldenvironments. Just as general training andcompetition strategies should be tailored forindividual athletes in accordance with theirunique needs and preferences, so should theirdrinking and eating choices during exercise.Athletes, coaches and trainers should fine-tunethese recommendations to identify their ownwinning formula.How much to drink?Athletes should generally limit dehydrationduring workouts and competitions by trying todrink at a rate that is close to sweat rate andthus limit loss of body weight (see the box onpage 20).It may not be necessary to drink enough toprevent loss of body weight, but the amount ofdehydration should be limited to no more thanabout a 2% loss of body weight (i.e., 1.0 kg fora 50 kg person, 1.5 kg for a 75 kg person, and2 kg for a 100 kg person). Greater losses willnegatively impact performance.In warm environments, try to minimizedehydration, as dehydration and exerciseintensity interact to increase the risk ofheat illness.Don’t drink so much that you actually gainweight during exercise, unless you beganexercise already dehydrated.When it is not possible to drink duringheavy-sweating type exercise lasting longerthan 30 minutes, practise drinking during the15 minutes before exercise and find out howmuch is initially filling but comfortable onceexercise begins (e.g., 300-800 ml).When do you need more than water?In terms of proven performance benefits, nonutrients match water and/or carbohydrate.During exercise lasting longer than 1 hourand which elicits fatigue, athletes are advised toingest 20-60 grams per hour of carbohydratethat is rapidly converted to blood glucose. Thisgenerally improves performance — allowingyou to maintain your pace, skills andconcentration instead of succumbing to fatigue.The use of commercial sports drinks with acarbohydrate content of about 4-8% (4-8 g/100ml) allows carbohydrate and fluid needs to bemet simultaneously in most events. Thiscarbohydrate can come from sugars (i.e.,sucrose, syrups containing no more than 50%fructose, glucose), maltodextrins or other rapidlydigestible carbohydrates. It is best for athletesto stick to well-known sports drinks that theyare familiar with to avoid gastrointestinaldistress or other consequences.If carbohydrates are ingested immediatelybefore exercise or during rest periods in a longcontest (more than 40 minutes), it is sometimesbeneficial to continue to ingest 20-60 grams18

athletes’ medical informationper hour throughout the contest. This maintainsthe flow of glucose into the bloodstream.Sodium should be included in fluidsconsumed during exercise lasting longer than1-2 hours or by individuals during any eventthat stimulates heavy sodium loss (i.e., morethan 3-4 g of sodium, see next page forassessment).Caffeine contained in commonly availablebeverages and foods can enhance endurancepower during the later stages of prolongedexercise. This benefit can be obtained withrelatively small doses of caffeine (about 2 mg/kg body weight; e.g., 150 ml of brewed coffeeor 750-1,000 ml of a cola beverage) that arecommonly consumed by people of variouscultures.Special strategiesAthletes who have dehydrated to make weightwill need special strategies for drinking beforeand during competitions to optimiseperformance.Athletes training and competing whilepractising fasting during the month of Ramadanmust rehearse a hydration strategy thatpreserves performance and protects health.Just like shoes, don’t try out new plans forfluid and fuel intake during importantcompetition. Do it in practice and findwhat fits you best.Rehydration after exerciseReplacement of water and salts lost in sweat isan essential part of the recovery process. Aim todrink about 1.2-1.5 litres of fluid for each kg ofweight loss in training or competition. Drinksshould contain sodium (the main salt lost insweat) if no food is eaten at this time. Sportsdrinks and pharmacy oral rehydration solutionsthat contain electrolytes are helpful, but manyfoods can supply the salt that is needed. A littleextra salt may be added to meals when sweatlosses are high, but salt tablets should be usedwith caution.Recovery after exercise is part of thepreparation for the next exercise session, andall athletes, including strength and powerathletes, will perform below their best if they arenot well hydrated when they begin exercise.

athletes’ medical informationPractical hydrationmessagesSevere dehydration impairs performance andincreases the risk of heat illness, but drinkingtoo much can also be harmful or uncomfortable.Every athlete is different because they havedifferent sweat losses and differentopportunities to drink fluid during their workoutsand events. You need a personal hydration planand YOU have to play a role in developing this.Remember that humans do not adapt todehydration, but may learn to complain lessabout it.Follow these three simple steps to check onyour hydration.1. Start training well hydrated. If you arepassing urine less often than normal, you maybe dehydrated. If urine colour becomes darkerthan what is normal for you, then you may notbe drinking enough. Check your urine colouragainst the chart. The aim should NOT be foryour urine to be as pale as possible. Develop adrinking plan for training and competition that isright for you, based on sweat losses (see Table).2. Monitor your sweat losses and the successof your drinking plan during training sessions indifferent situations (see Table). How did youfeel? How did you perform? What was yourweight loss over the session? This shouldgenerally not exceed about 1-2% of body mass.If you lost more than this, you probably did notdrink enough. Drink more next time. If you lostless, you might have drunk too much. Did itmake you feel uncomfortable? Did you taketime out to drink that was unnecessary?3. If you are a ‘salty sweater’, you may needdrinks with more salt and may need more saltin food when sweat losses are high. To checkwhether you are a salty sweater, wear a blackT-shirt in training and look for salt stains (whitepowder) under the arms and on the chest.High salt losses are a contributing factorin some cases of muscle cramp. Sports drinkswith higher salt (sodium) levels (e.g., 300-500 mg sodium per 500 ml liquid) may helpreduce the risk of cramps.How to estimate sweat losses andsweat rates:1. Measure body weight both before andafter at least 1 hour of exercise underconditions similar to competition or a hardpractice.2. Take these body weight measurementswearing minimal clothing and whilebarefooted. Towel dry after exercise andobtain body weight as soon as is practicalafter exercise (e.g., less than 10 min,and before eating, drinking or going to thetoilet).3. Estimate the weight of any fluid orfoods you have consumed during theworkout (e.g., 500 ml of fluid = 500 g or0.5 kg).Sweat loss (litres) = Body weight beforeexercise (in kg) — body weight after20

athletes’ medical informationexercise (kg), + weight of fluids/foodsconsumed (kg). Example: 74.5 kg —72.8 kg + 0.80 kg (800 ml fluid) = 2.5 kg.4. To convert to a sweat rate per hour,divide by the exercise time in minutesand multiply by 60.5. Your weight deficit at the end of thesession provides a guide to how well youhydrated during the session and howmuch you need to rehydrate afterwards.To convert kg to % body weight, dividethe weight deficit by starting bodyweight and multiply by 100: e.g.,1.7 kg/74.5 X 100 = 2.3%.Note: 2.2 pounds equals 1.0 kg andconverts to a volume of 1.0 litre or1,000 ml or 34 ounces of water.123456Pale YellowStrawGolden YellowGolden OrangePale AmberAmberDrinking so much that you gainweight during competition is neverlikely to be a good idea. The onlytime you might need to do this iswhen you have been dehydratedat the start of the event.789Rich GoldenAmberCopper BrownOrange BrownUse this chart (right) tocheck your urine colour. Ifthe colour is dark, you mayneed to drink more.1011Mid BrownRuby Brown21

athletes’ medical informationSpecial needs of theyoung athleteEvery child and adolescent around the worldshould have the opportunity to participate insport and should be encouraged to do so. Sportoffers the benefits of aerobic fitness, skilldevelopment and a team environment. Girls andboys can start practising and competing at anearly age, though the focus should be on funand on skills development rather than onperformance. Nonetheless, most children arenaturally competitive and it would be a mistaketo suppress this instinct. Those with particulartalent may progress to serious training andcompetition, but others continue for reasons ofrecreation, fitness or social contact.Training issuesDepending on the age and calibre of the youngathlete, ‘training’ may range from the weeklyschool PE lesson to structured sessions at alocal club. The goals of training may range fromsimply having fun through to a progressiveprogram aimed at developing the skills andspecific fitness and physique required toprogress to serious competition. Talented youngathletes may be invited to train with another agegroup or with a senior squad, often in additionto their involvement with their age-group team.Competition issuesFor the youngest age groups, there should beno special need for any change to diet in thedays before competition or on competition dayitself. The main aims are to minimise the risk ofgastrointestinal upset and to avoid problemsof dehydration on hot days. It may be bestto avoid solid food for 2-3 hours beforecompetition — the combination of exerciseand nerves can cause some gastric distress.Children can often be out in the sun formany hours on sports days, and adults shouldbe vigilant to ensure frequent application of suncream and be aware of any child who seemsto be having problems. Ample fluid should beavailable, and children may need to bereminded to take small amounts of drinksat regular intervals.Special issues and eating strategiesParents are often roped in to become thecoaches and trainers of age-group teams.They may accept these positions without anappreciation of the nutritional needs of the sportor young people, and without any resources toimplement an effective training and diet program.It is important that education resources are madeavailable to these coaches so that they can guideyoung athletes into good habits.Athletes should be encouraged to developgood nutritional habits at an early age.Adolescence is a time marked by an increasedindependence, and this extends to greaterfreedom of food choice and greater responsibilityfor food preparation. The promise of sportingsuccess may provide strong motivation todevelop good dietary practices. Information andthe example of good role models may help ayoung person to develop sound eating practicesin everyday (training) diets as well as thespecific preparation for competition.The physiology of children and adolescentsdiffers from that of adults in several ways. Themechanisms of thermoregulation are less22

athletes’ medical informationeffective in children, and special attention mustbe paid to the environment, activity patterns,clothing and hydration to avoid problems ofhyperthermia or hypothermia.The growth spurts during childhood andadolescents require nutritional support in termsof adequate intake of energy, protein andminerals. Active young people may find itdifficult to meet their needs for energy andnutrients when the costs of training and growthare added. Young people may not havedeveloped the nutritional knowledge andtime-management skills to fit in all the eatingoccasions required to achieve high-energy,nutrient-rich eating.The rate of obesity in children is still rising,but active youngsters do need a plentiful supplyof energy from foods and energy-containingdrinks. Young athletes have been shown to drinkmore of a flavoured sports drink than waterduring activity, which is an importantconsideration especially if exercise is in theheat. Sports drinks should be made available toencourage more fluid intake.Many young athletes are eager to increasethe rate of their growth and musculardevelopment in pursuit of the physique of anadult. While growth and maturation aregenetically determined, high-energy eatingplans can assist the young athlete to maximisethe outcomes of growth and specialised trainingprograms.Young athletes eating a wide range of foodsshould not need to use dietary supplements,including the use of energy drinks whichcontain high amounts of caffeine and are notsuitable for young athletes. Athletes andcoaches should be aware that supplements donot provide a short-cut to success.Ways to encourage good nutrition practicesin childrenEncourage children to become involved in menuplanning for the family meals, and for specialneeds associated with their training andcompetition sessions. Encourage positivemessages that good eating practices, involvinggood choices of foods and drinks, are part of theformula for sporting success, and a healthy life.Children often need snacks to meet theirenergy needs over the day, and the specialneeds of recovery from sport. These snacksshould involve nutrient-rich choicessuch as fruit, sandwiches, driedfruit and nuts/seeds mixes,flavoured milk and yoghurt,and cereals with milk. Someplanning is needed to havethese choices on handover the day, andbefore orafter sport.23

athletes’ medical informationSpecial needs of thefemale athleteGeneral health issuesAll female athletes should eat sufficient food toachieve an energy intake that:• provides sufficient energy for training andcompetition needs• meets the energy demands of other dailyactivities• allows the athlete to achieve a body size and composition that meets her health andfitness goalsSome athletes do not achieve this andrestrict food intake to achieve their desiredweight at the expense of both health andperformance.Losing body fatThere is enormous pressure on many womento achieve an unrealistic body weight and bodyfat level. This can compromise both short-termathletic performance and long-term health,with the real possibility of harm to reproductivehealth and to bone health. Any athlete withmenstrual irregularities should treat these asa possible warning sign and seek professionaladvice.If there is a need to reduce body fat, thisshould be done sensibly. Reducing body fatrequires a negative energy balance — energyexpenditure should be greater than energyintake — and a negative body fat balance. It isa mistake to reduce energy intake — especiallyprotein and carbohydrate intake — too far. Thisincreases fatigue in training and daily life,reducing energy levels and thus limiting weightloss. Severe energy restriction reduces theeffectiveness and progress in the trainingprogram, and in turn compromises competitionperformance.Strategies for reducing body fat• Set realistic targets: this is a mediumtermgoal rather than something to beachieved by next week.• Limit portion sizes at meals rather thanskipping meals altogether.• Use well-chosen snacks between mealsto maintain fuel levels for trainingsessions. Save part of a meal for a latersnack, rather than eating extra food.• Maintain carbohydrate intake tomaintain fuel levels for exercise.• Use low-fat strategies in choosing foodsand while cooking or preparing meals.• Limit alcohol intake or cut it outaltogether — it is not an essential partof the diet.• Make meals and snacks more fillingby including plenty of salads andvegetables, by taking the higher-fibreoption, and by including low glycaemicindex forms of carbohydrate-rich foods(e.g., oats, legumes, dense-grainybreads, berries, apples, etc.).24

athletes’ medical informationCalcium. Calcium is important for healthybones. In some countries, many everydayfoods are fortified with calcium (e.g.,fruit juice). However, the best sourcesof calcium are dairy foods, with low-fatvarieties providing a great way to meetcalcium needs within a smaller energybudget.• Each athlete should aim to include atleast 3 servings of dairy foods in theirdaily eating plans — e.g., 200 ml oflow-fat milk, 30 g cheese or a 200 mlcarton of low-fat yoghurt.• Calcium-fortified soy versions of dairyfoods are also suitable — e.g., soy milk,soy yoghurt.• An additional 1-2 daily servings arerequired during growth spurts inchildhood and adolescence, and forpregnancy and when breast feeding.• Fish eaten with bones (e.g., tinnedsalmon, sardines) and leafy greenvegetables (e.g., broccoli, spinach)provide a useful source of additionaldietary calcium.Iron. Iron deficiency is a cause of fatigueand reduced performance. Females areparticularly at risk because of increasediron requirements due to menstrual bloodlosses matched against a smaller intakeof food. Iron-rich eating will help to reducethis risk. Athletes at risk should perhapsbe monitored on a routine basis.Iron-rich eating• Consume moderate servings of redmeats (well-absorbed iron) in 3-5 mealsper week.• Choose iron-fortified cereal productssuch as breakfast cereals.• Combine plant and non-meatsources of iron (e.g., legumes,cereals, eggs, green leafyvegetables) with food factorsthat enhance iron absorption.These include Vitamin Cand a factor foundin meat/fish/chicken.Examples of clevermatching includefruit juice or fruitwith breakfastcereal, or chillicon carne (meatand beans).

athletes’ medical informationSupplements andsports foodsAthletes look to nutritional supplementsfor many benefits, including:• promoting adaptations to training• increasing energy supply• allowing more consistent and intensivetraining by promoting recovery betweentraining sessions• maintaining good health and reducinginterruptions to training due to chronicfatigue, illness or injury• enhancing competitive performanceSupplement use is widespread amongsportsmen and women, but few of theseproducts are supported by a sound researchbase and some may even be harmful to theathlete. Athletes should look carefully at therisks and rewards of individual supplementsbefore trying them.Where there is a demonstrated deficiencyof an essential vitamin or mineral, and anincreased intake from food is not possible,a supplement may be helpful. The use ofsupplements, however, does not compensatefor poor food choices and an inadequate diet.Many athletes ignore the need for caution insupplement use and take supplements indoses that are not necessary, and may evenbe harmful.Protein powders and supplementsProtein supplements, high-protein bars andamino acid preparations are among the biggestsellingsports nutrition products. An adequateintake of protein is essential for muscle growthand repair, but this can easily be achieved fromeveryday foods and extra protein is seldomrequired (see pages 12-13).Protein-carbohydrate supplements mayhave a role as part of a post-exercise recoveryplan, but whole proteins have advantages overindividual amino acids.Fat reduction and muscle buildingA huge array of supplements is on sale withclaims that they can reduce body fat levels andbuild bigger and stronger muscles — claimsthat appeal to athletes and non-athletes alike.The reality is that many of the productsthat are effective in doing this are either onthe banned list or are associated with serioushealth risks (or both).Compounds in the muscle-building categoryinclude chromium, boron, hydroxymethylbutyrate(HMB), colostrum and others. Based on currentresearch, none of these has anything worthwhileto offer the athlete.Increasing energy supplySupplements in this category include pyruvateand ribose as well as some more exotic herbalpreparations. None of these is likely to improveperformance and, in spite of advertising claims,none is supported by good independentevidence. There is now limited evidence thatcarnitine can affect exercise metabolism insome circumstances, but the evidence forperformance effects is not convincing.26

athletes’ medical informationNutrition and the immune systemThere is some evidence that athletes who aretraining hard may be at increased risk of minorillnesses and infections. In themselves, theseare generally trivial, but they can interrupttraining or cause an athlete to miss importantcompetitions. Hard training may compromisethe body’s immune system, and high levelsof stress hormones reduce its ability to fightthese infections.Many nutrition supplements, includingglutamine, zinc, echinacea, colostrum andothers, are on sale with claims that they canboost the immune system, but there is nostrong evidence that any of these is effective.The best strategies to support a healthyimmune system include scheduling appropriaterest periods and matching carbohydrate intaketo fuel needs. There is good evidence thatcarbohydrate intake during prolonged exercisereduces the release of stress hormones.Supplements for bone and joint healthHard training puts extra wear and tear on thebones, joints and associated structures, andnumerous supplements are claimed to lookafter these tissues.Healthy bones need a good supply ofcalcium and Vitamin D. In most cases, thesenutrients can be supplied by the diet. Athleteswho suffer from problems related to suboptimalbone density should seek professional adviceand supervised treatment from a sportsphysician.Glucosamine, chondroitin,methylsulphonylmethane (MSM) and otherproducts are promoted for joint health. Thereis some evidence that long-term (2-6 months)glucosamine treatment can provide subjectiverelief in elderly individuals suffering fromosteoarthritis, but evidence is lacking for abenefit such as a ‘joint protective’ effect fromhigh-intensity training in healthy athletes.Supplements that might workSome supplements do offer the prospect ofimproved performance: these include creatine,caffeine, bicarbonate, -alanine and perhapsa very few others.Creatine. Creatine supplements can increasethe amount of high-energy creatine phosphatestored in the muscles and may improveperformance in single or multiple sprints. It mayalso lead to a gain in strength and/or musclemass, which is helpful for some athletes, butthe extra weight may be harmful for others. Aswith all supplements, exceeding the maximumeffective dose is not helpful. Creatine isnormally found in meat and fish, but theeffective doses (10-20 g per day for 4-5 days toload, and then 2-3 g per day for maintenance)are more than is found in normal foods.Creatine supplementation does not appearto be harmful to health.Caffeine. A small amount of caffeine (1-3 mg/kg) can help performance in prolonged exerciseand may also be helpful in exercise of shorterduration. Such moderate doses can be foundin everyday amounts of coffee, cola drinks andsome sports products (e.g., gels). For example,27

athletes’ medical information100 mg of caffeine is supplied by a small cup ofbrewed coffee or 750 ml of a cola drink. Largerdoses of caffeine do not seem to be moreeffective and may have negative outcomes suchas anxiety, gastrointestinal distress, overarousaland poor sleep patterns after an event.This is likely to be a problem in multi-day eventsand in sports involving heats and finals.Energy drinks. These sugary caffeinateddrinks should not be confused with sportsdrinks, which are designed to rehydrate thebody during exercise. In fact, energy drinks area poor choice to consume when exercising(especially in the heat) due to high sugarcontent, which can impair fluid absorption.While energy drinks may seem refreshing andhydrating, they should not be consumed before,during or after exercise when you need toreplace sweat loss. These drinks may also bepotentially dangerous if used in excess or incombination with other stimulants or alcohol.Lastly, energy drinks may be tainted withprohibited substances, such as those derivedfrom unregulated herbals. Most drinks are nottested for purity or contamination and couldlead to a positive doping test.Buffering agents. In very hard exercise, themuscles produce lactic acid. This is both good(giving energy to allow hard efforts) and bad(causing pain and interfering with musclefunction). In the same way that excess stomachacidity can be neutralised by taking bicarbonate,so can taking sodium bicarbonate (in a dose ofabout 0.3 g per kg BW) before an event tocounter the harmful effects of lactic acid. Thiscan help in all-out events lasting from about30 seconds to 8 minutes. There is a risk ofgastrointestinal problems, and athletes shouldexperiment in training. Sodium citrate mayalso be effective. More recently, -alaninesupplements have been shown to increasemuscle levels of carnosine, an importantbuffer, and to improve performance in somehigh-intensity exercise models.A number of sports foods have beendeveloped to supply a specific formulationof energy and nutrients in a form that iseasy to consume. These can be valuablein allowing athletes to meet their specialnutrition needs when everyday foods areunavailable or impractical to eat. This ismost often the case just prior to, during,or after an exercise session. Examplesof useful sports foods include:• sports drinks (providing fluid andcarbohydrate during exercise)• sports gels (additional carbohydrateintake, especially during exercise)• liquid meals (carbohydrate, protein,vitamins and minerals for a pre-eventmeal, post-exercise recovery or ahigh-energy diet)• sports bars (carbohydrate, protein,vitamins and minerals — often a solidform of the liquid meal)Of course, the cost of these sports foodsmust be taken into account when decidingto use them.28

athletes’ medical informationSupplements and dopingAthletes who are liable for drug testing undernational or international programs should beespecially cautious about supplement use.Some supplements are prepared inunhygienic conditions and contain toxins thatmay cause gastrointestinal problems. Othersdo not contain some or all of the ingredients— especially the expensive ones — that arelisted on the label. Contamination of dietarysupplements with substances that may causean athlete to fail a doping test is widespread— some surveys have suggested that as manyas one in four supplements may result in apositive test. These prohibited compounds havenot been declared on the label, so there is noway for the athlete to know that they are present.Purchases through the Internet pose an evengreater risk, and extreme caution should betaken. A sports nutrition expert should beconsulted before taking any supplements.At present, there can be no guarantee of thepurity of any commercial supplement. The onlyway to be sure is to avoid supplementsaltogether, but many athletes are unwilling toaccept this advice. The sensible athlete willwant to see very good reasons for using asupplement and a very low risk of an adversetest before deciding to use it.There is no evidence that prohormones suchas Androstenedione and Norandrostenedioneare effective in enhancing muscle mass orstrength. These prohormones are promoted foruse by athletes and are readily available inshops and via the Internet, but they will resultin negative health consequences as well aspositive drug tests.Many herbal supplements are claimed toincrease testosterone levels and hence havean anabolic action. These include: TribulisTerrestris; Chrysin; Indole-3-Carbinol; SawPalmetto; Gamma-oryzanol; Yohimbine; Smilax;Mummio. All of these claims are based onstudies in test tubes and none has been shownto work in humans. Athletes are cautionedagainst the use of these supplements.Athletes must be aware of the strictliability principle that makes themresponsible for everything they eatand drink.Ignorance is not an acceptableexcuse for a positive doping result.Check all supplements with amedical officer or qualified sportsnutrition specialist. If there is anydoubt at all, don’t take it.29

athletes’ medical informationSpecial needs for powerand sprint sportsTraining issuesThe goal of many power and sprint athletes isto enhance muscle mass and strength throughspecially designed resistance-trainingprograms. In most cases, these athletes believethat their food focus should be on proteinintake. In fact, there is no evidence that veryhigh intakes of protein (>2 g per kg BW) arenecessary or even advantageous for optimizingthe results of resistance training. It is likely thatthe best results are achieved through enhancedrecovery strategies, such as providing a sourceof protein and carbohydrate soon after theworkout, and achieving adequate total energyintake over the day. It is probably also valuableto spread protein intake over the day’s meal andsnack schedule rather than stacking it all intoone or two meals.Many power and sprint athletes forgetto bring a drink bottle to training. However,workouts are best undertaken when the athleteis well-hydrated and well-fuelled. Fuelling witha sports drink can help the athlete to keeplifting or training with a good technique, rightto the end of a long session.There are numerous supplements that claimto promote recovery, increase muscle mass,reduce body fat and enhance performance.These claims are attractive to all athletes, butseem particularly entwined with the world ofbody building and strength training. Manyathletes are not aware that the claims made formost products are unsupported or exaggerated,and that the industry operates with littleregulation.Competition issuesMost sprint events are conducted over ashort time, with minimal impact on fluid andcarbohydrate levels. However, competition canrequire the athlete to compete in a series ofheats, semis and finals, or with long periodsbetween rounds of a field event or multi-sportcompetition. This calls for special eatingstrategies to recover between events or tomanage fluid and energy levels over a long day.Eating strategies for power andstrength athletesA key ingredient in a plan designed to enhancemuscle size and strength is adequate energyintake. Energy should be supplied both bycarbohydrate-rich foods that provide fuel fortraining as well as protein- and nutrient-richfoods that can provide building blocks for theresults.Recent evidence suggests that enhancedeffects on protein balance are achieved byfollowing up a resistance workout with a mealor snack providing a good source of protein andcarbohydrate soon after the session. When totalenergy needs for the day are high, having asnack before and after the workout can helpto meet targets.A few supplements and sports foods providevaluable benefits to the athlete’s training andcompetition program. It is important for theathlete to seek up-to-date and independentadvice from a sports nutrition expert to identifythese products and how to use them to suitthe athlete’s current program, budget andperformance goals.30

athletes’ medical informationOn the day of competition, the athleteshould consume a comfortable pre-event mealand organise appropriate carbohydrate-richdrinks and light snacks to stay fuelled andhydrated between events or bouts in amulti-event program.Strategies for high-energy eatingIt is usually more efficient to increase thenumber of times that food is eaten each day— for example, a series of 5-9 meals andsnacks — rather than trying simply to increasethe size of meals. Drinks such as fruitsmoothies, liquid meal supplements andfortified milkshakes and juices can provide asubstantial source of energy and nutrients thatare quick and compact to consume, and lesslikely to cause gastrointestinal discomfort thanbulky foods. Sugary foods and specialisedsports products (drinks, bars) can provide amore compact form of carbohydrate and othernutrients, which is particularly useful whenenergy needs are high. A food record canidentify the times in a busy day that aren’t beingwell used for fuelling up. The athlete shoulduse creative ideas and good planningto arrange a supply of portablesnacks and drinks that cantravel with them overtheir day.Food combinations supplyingcarbohydrate and protein• Breakfast cereal and milk• Sandwiches with meat, cheese oregg fillings• Meat/fish/chicken stir-fries servedwith rice or noodles• Fruit smoothies or liquid mealsupplements• Fruit and yoghurt• Dried fruit and nut mixes• Meals or snacks can be quicklypartnered with a missing nutrient byadding 500 ml of milk (protein), 500 mlof juice (carbohydrate) or 500 ml offlavoured milk (protein + carbohydrate)31

athletes’ medical informationSpecial needs forendurance sportsTraining issuesA demanding endurance training programusually involves daily or twice-daily workouts.Inadequate refuelling leads to fatigue andineffective training.Low body fat levels may benefit performanceand are pursued obsessively by some athletes.Severe restriction of energy intake and dietaryvariety can lead to chronic fatigue, reducedperformance, nutritional deficiencies, hormonalimbalances and disordered eating. In addition,endurance athletes’ weights will often flux inthe season, and it may be unhealthy, stressfuland impractical to maintain very low bodyweights/fatness all year long.Lengthy, high-intensity workouts lead tohigh sweat losses, particularly in hot weather.Requirements for protein, vitamins andminerals may also be increased by a heavytraining load.Competition issuesThe main factors causing fatigue duringcompetition are fuel (carbohydrate) depletionand dehydration. Strategies for eating before,during and after the event are important toreduce these effects.Competition is often undertaken in multiplestages, or as a series of heats and finals.Recovery between sessions can be importantin determining the final winner.Eating strategies for the endurance athleteTo achieve carbohydrate intake targets to meetthe fuel demands of training and recovery,meals and snacks should be based aroundcarbohydrate-rich foods such as:• Breads and flour-based foods (e.g., rolls,scones, low-fat muffins)• Rice, pasta, noodles and other grain foods• Breakfast cereals (cold or hot)• Fruits (fresh, frozen or canned)• Starchy vegetables (corn, potatoes), beansand legumes• Flavoured dairy foods (e.g., chocolate milkand fruit yoghurt)• Sugary foods and drinks (juices, occasionalsweets)Nutrient-dense carbohydrate choices, andthe addition of protein-rich foods andvegetables to meals, will help to balance fuelneeds and other nutrition goals. Sugary foodsand drinks provide a compact form ofcarbohydrate, which is particularly useful whenenergy needs are high or in situations when itis impractical to eat bulky foods.Endurance athletes with very high energyneeds may find it valuable to spread their dailyfood intake over a series of meals and snacks.Drinks providing carbohydrate (sports drinks,soft drinks, juices, fruit smoothies andmilkshakes) also provide a compact wayto refuel.Key strategies to achieve lighter and leanerphysiques include low-fat eating and attentionto portion sizes. Well-placed snacks may helpprevent hunger and energy drain over the dayand may prevent overeating at the next meal.32

athletes’ medical informationFluid and fuel replacement are key issuesduring most competitive events, and the athleteshould prepare for competition by fuelling up inthe day(s) leading up to the event and ensuringthat they are well-hydrated. For events lastinglonger than about 90-120 minutes, manyathletes carbohydrate load, by tapering theirtraining and increasing carbohydrate intake for2-3 days prior to the race.The pre-event meal offers a final way totop-up fuel and fluid levels, and menu choicesshould be based around carbohydrate-richeating. The ideal amount and type of foods anddrinks, and the timing of the pre-event meal,will vary between athletes and should befine-tuned with experience to avoidgastrointestinal disturbances during the event.In long events there may be a need andopportunity to refuel and rehydrate ‘on the run’.Sports drinks provide a good balance of fluidand carbohydrate to meet both goals, and aredesigned to taste good to encourage intake.Each athlete should develop a fluid intake planbased on knowledge of expected sweat lossesand how much of this is practicable to replace.Fluid intake should not exceed sweat losses. Invery long events, sports bars, gels and everydaycarbohydrate foods provide an additional sourceof carbohydrate for variety and extra fuel intake.Typically, a fuel intake of ~20-60 g per hour issuitable, but should be fine-tuned according toindividual needs and experience. Race daystrategies should be tried in training, both toenhance the session and to fine-tune thecompetition plan.After a race or workout, the athlete shouldeat and drink to promote quick recovery. Lightand portable recovery snacks are a usefulchoice until the normal meal pattern isresumed.Carb choices for race fuel: 30 g carb isprovided by:• 400-500 ml of a sports drink —250 ml of a defizzed soft drink• ~1 packet sports gel• ~ ¾ sports bar (low-fat, moderateprotein)• 1 large or 2 small bananas• 1 thick slice of bread and jam/honey• 35-40 g candy/confectionery• Remember fluid needs too!33

athletes’ medical informationSpecial needs forteam sportsTraining issuesMany team sports involve seasonal competition.At the recreational level, the off-season can belengthy and players often lose fitness and gainbody fat as a result of detraining and pooreating practices. This may also occur during theseason when players are injured. At the elitelevel, most team athletes train all year, with justa brief break between seasons.Refuelling is an important part of therecovery between matches, and from the teamand individual training sessions that occurbetween games. Traditionally, many teamplayers have focussed on fuelling up only onthe day before a match or in the pre-eventmeal. However, the daily demands of trainingare best met by a permanent approach toadequate fuel intake.Physique is important in the performance ofsome sporting codes, or positions within a code.Many team athletes have special nutritionalneeds to support a resistance training program,or a rapid growth spurt. While protein needs areoften emphasised, total energy and fuel intakeand the timing of meals/snacks in relation totraining are perhaps more important.Large fluid losses often go unrecognised inteam sports, or are even promoted as a meansto lose weight or ‘toughen up’ players.High-intensity work creates large sweat losseseven in cold weather, and special needs shouldbe recognised in warm conditions or whenheavy clothing and protective gear is worn. Inaddition, many athletes (often in hockey) swishand spit, and may fail to recognise that thisdoes not aid hydration.Match issuesCompetition can be played in weekly leaguegames, or as a tournament with games everyday or several days. Recovery needs must beadjusted according to the schedule.Depletion of fuel stores can be an issue forteam games lasting longer than 60 minutes,especially for players in mobile positions orwith a running game style. High carbohydratestrategies — fuelling up for the game andconsuming extra carbohydrate during the match— have been shown to enhance performancein team sports. Hydration strategies are alsoimportant for optimal performance. Bettermatch nutrition may not only keep playersrunning further and faster in the second halfof a match but may help to maintain skills andjudgement when players would otherwisebecome fatigued both physically and mentally.Games are often won and lost in the lastminutes of the match, and fatigued players areat increased risk of injury.Eating strategies for team athletesTeam-sport players may adopt the eatingstrategies outlined for endurance athletes,and should eat well and stay active all yearround. The following strategies may be ofadditional value.Many team sports have a large contingentof young players who are ‘fresh from home’.It is a good team strategy to organise cookingand shopping classes for young players to helpthem develop the domestic skills and nutritionknowledge that will allow them to reach theirfull potential as players. Athletes looking after34

athletes’ medical informationthemselves for the first time can find it hard tojuggle the team commitments, as well as work/school. Many recipe books developed forathletes offer quick and nutritious meal ideassuited to the special needs of sport.The pre-event meal is a good opportunityfor a shared meal, ensuring good last-minutenutritional preparation as well as an opportunityto boost morale and share final tactics. Ideas forpre-event meals are found on pages 16-17,and are best provided as a buffet, to allow eachteam member to choose their individual needsand likes.Various opportunities exist for players torefuel and rehydrate during team sports —these include quarter or half-time breaks,substitutions and time-outs. Some codes evenallow trainers to carry drinks to players on thearena during breaks in play. A creative planshould be developed for each team.Post-game or post-training recovery isanother good opportunity for team nutrition.Alcohol is often a large part of post-gameactivities in team sports but should bediscouraged, unless in moderation and afterrecovery eating goals are achieved. Post-gamesnacks and light meals providing nutritiousforms of carbohydrate and protein as well asrehydration options will help players to recovereffectively while celebrating or commiseratingthe results of the match.Ideas for post-exerciserecovery snacksEach choice provides ~50 g carbohydrateand a valuable source of protein and othernutrients• 250-350 ml fruit smoothie orliquid meal• 60 g (1-2 cups) breakfast cereal + milk+ 1 fruit• 200 g carton of yoghurt + cereal/breakfast bar• 1 round of meat/cheeseand salad sandwichesor roll + 250 mlfruit juice• 150 g thick-crustpizza — lean meat andvegetable toppings andeasy on the cheese• 60 g sports bar + 250 mlsports drink

athletes’ medical informationSpecial needs for weightconscioussportsTraining issuesThe key nutritional interest of many athletes isto reduce body weight and body fat. A low levelof body weight and body fat often provides abenefit to performance. In other sports involvingsubjective outcomes (e.g., gymnastics, diving,body building), the athlete who is lean and trimis judged to have a higher aesthetic appeal.Although certain body shapes and physiquesare held up as de rigueur for many sports, eachathlete must be realistic in setting targets forthe weight- and fat-loss programs theyundertake.Challenges occur for the athlete whosetraining does not involve high-energyexpenditure work — for example, the athletewho undertakes lengthy training sessions thatare primarily based on skill and agility. It is moredifficult to create the energy deficit needed toreduce weight and body fat when basal energyneeds are low to moderate.Restrictive eating and fad diets can lead todehydration and fuel depletion, marring trainingperformance and increasing the risk of injuryand accidents, rather than achieving effectiveloss of body fat.Competition issuesIn many combat sports (boxing, wrestling,martial arts), some strength sports (weightlifting) and lightweight rowing, competitioninvolves weight divisions that attempt to providea match between athletes of equal size andperformance. In such sports, athletes typicallytry to lose weight in the days before thecompetition (and its pre-event weigh-in),in order to qualify for a weight division that islighter than their habitual body weight and gainan advantage over a smaller opponent. Acutestrategies to make weight expose the athleteto health and performance risks arising fromdehydration, fuel depletion, inadequate nutrientintake and psychological stress.Strategies for athletes inweight-conscious sportsAthletes will benefit from professional advicefrom an expert such as a sports dietitian to setrealistic goals for weight- and fat-loss attempts,and a suitable long-term eating plan.The athlete in skill-based sports shouldseek their coach’s input to introduce or increaseaerobic workouts that can increase overallenergy expenditure without detriment to keytraining sessions. This may include changesto lifestyle to increase incidental exercise oractivity in the day.Athletes who compete in weight divisionsports should settle for a weight category thatis close to the training weight that can beachieved with a safe and healthy plan. Finalfine-tuning of weight prior to the event shouldnot involve changes of >1-2% body weight,and should be undertaken without resorting toextreme techniques of dehydration and fasting.Proper and timely refuelling after weigh-in isalso critical to ensure optimal competitionperformance.Athletes in weight-conscious sports maybe at higher risk of disordered eating andeating disorders than other athletes or thesedentary population. It is important that36

athletes’ medical informationathletes who develop warning signs of suchproblems are referred at an early stage forexpert team-based advice.Strategies for staying lean and trimAssess portion sizes at meals to ensure thatover-eating does not occur due to habit orunnecessary hunger.Use well-chosen snacks between mealsto maintain fuel levels for training sessionsor to avoid excessive hunger. However, avoidsnacking for entertainment or comfort. Snackscan often be organised by saving part of ameal for a later occasion, rather than by eatingextra food.Use low-fat strategies in choosing foods andwhile cooking or preparing meals.Make meals and snacks more filling byincluding plenty of salads and vegetables, bytaking the higher-fibre option, and by includinglow glycaemic forms of carbohydrate.A food record will help to identify thedifference between an athlete’s desired eatingplan and their actual intake. Many peopleare unaware of the habits that sabotagetheir eating goals.Examples of incorporating lowglycaemic index carbohydrate foodsinto meals• Enjoy rolled oats (porridge or low-fatversions of Bircher Muesli) instead ofCornflakes for breakfast• Replace white and whole meal breadswith whole grain and multi-grain choices• Add lentils and legumes to casserolesand pasta sauces• Enjoy flavoured yoghurt as a snack• Replace mashed potatoes with al dentepasta or buckwheat

athletes’ medical informationSpecial needs for thetravelling athleteMost elite athletes are well-seasoned travellers,seeking competition or specialised trainingenvironments far away from home. In manyteam sports, high-level competition is organisedin a national or regional league that requiresweekly or biweekly travel to matches. Frequenttravel can pose a number of challenges:• Disruptions to the normal training routineand lifestyle while the athlete is en route• Changes in climate and environment thatcreate different nutritional needs• Jet lag• Changes to food availability including absenceof important and familiar foods• Reliance on hotels, restaurants andtakeaways instead of home cooking• Exposure to new foods and eating cultures• Temptations of an all-you-can-eat dining hallin an Athletes’ Village• Risk of gastrointestinal illnesses due toexposure to food and water with poor hygienestandards• Excitement and distraction of a newenvironment• Changes in digestion and/or pattern of bowelmovements due to travelThe keys to eating well while travelling are:1. Plan ahead.Investigate food patterns and availability at yourdestination before you leave home. This mayhelp you to plan useful food supplies to takeon your travels that can replace missing andimportant items.Contact the catering organisers at yourdestination to let them know of your needsfor meal timing and menus.Make an eating plan for travel thatincorporates the best of the available foodsupplies (e.g., airline catering, restaurantsen route) as well as self-supplied snacks.2. Eat and drink well while on the move.Recognise that enforced rest while travellingwill reduce energy needs, but create moreopportunities for excessive energy intake ifthe athlete succumbs to ‘boredom eating’.Be aware of eating to real need.When moving to a new time zone, adopteating patterns that suit your destination assoon as the trip starts. This will help to adaptyour body clock.Be aware of unseen fluid losses inair-conditioned vehicles and pressurisedplane cabins. Have a drink plan that keepsyou well hydrated.3. Be wary of food and water hygiene.Find out whether it is safe to drink the localwater supply. If risky, stick to sealed bottles ofwater and other drinks or hot drinks. Be waryof ice added to drinks — it is often made fromtap water.In high-risk environments, stick to foodproduced in good hotels or well-knownrestaurants. Avoid eating food from local stallsand markets, however tempting it is to have anauthentic cultural experience.Stick to food that has been well-cooked, andavoid salads or unpeeled fruit that has been incontact with local water or soil.38

athletes’ medical information4. Choose well from local cuisine andsupplement with nonperishable foodsupplies brought from home.It is often a good idea to bring some snacks andfavourite foods with you, especially if you areaway from home for a long time and yourfavourites are not available at your destination.Remember, though, that many countries prohibitthe import of fresh foods: check ahead to seewhat is permitted and do not risk having theseconfiscated at the airport. Do not take the riskof trying to smuggle food — you may berefused entry.Ideas for portable supplies for thetravelling athlete• Breakfast cereal and powdered milk• Cereal and breakfast bars• Meal replacement, sport andprotein bars• Rice cakes, crackers, pretzels• Spreads — honey, jam, peanut butter• Powdered sports drinks and liquidmeal supplements• Dried fruit and nutshall before you start filling your plate. Thiswill help you make informed decisions onyour eating choices rather than the typicalsee-and-grab approach.Be assertive in asking for foods to beprepared to your needs — for example, withlow-fat cooking methods, or with an addedcarbohydrate serving.Avoid hanging around in restaurants ordining halls for entertainment — it can oftenlead to unplanned and unnecessary eating.Remember that your normal eating patternsprobably involve well-timed and well-chosensnacks. If your new catering arrangementsprovide only for main meals, ensure that themenu at meals includes some items that canbe taken away for snack needs.5. Use clever tactics in restaurants,all-you-can-eat dining halls and whenchoosing takeaways.Stick to an eating plan based on what isnormally eaten at home, or what meets newnutritional needs, rather than being mesmerisedby all the food on offer. Walk around the dining39

athletes’ medical informationEnvironmentalchallengesAthletes train and compete in every countryof the world, and they may face a number ofdifferent environmental challenges at home orwhen they travel for competition. The athletewho trains in winter in Russia or the AmericanMidwest is confronted with wind, snow andbitter cold, while the Saudi Arabian athlete whotrains in mid-summer may face temperatures of50°C and high humidity. In every case, however,athletes learn to cope, and it is often a matter ofpride never to miss a session because ofadverse weather conditions.Athletes are sometimes required to competein environments that are very different fromthose they are accustomed to at home, and thiscan pose special challenges. Every challenge,though, should be seen as an opportunity, andnutritional strategies can be adopted to helpathletes cope with environmental extremes.Heat acclimation is achieved best by about60-100 minutes of modest exercise in warmenvironment: about 10-12 sessions at intervalsof not more than 2-3 days will achieve this.Athletes not used to hot weather must beaware of the need to make some changes totheir routine:• It may be necessary to modify the warm-upand reduce the amount of clothing worn toprevent over-heating and excess sweat lossbefore competition begins.• Extra fluids may be necessary, and cool fluidsmay be especially welcome, so insulateddrinks bottles can help.• Sports drinks contain calories: too much canupset the athlete’s energy balance, so thismust be part of the overall eating plan.Special issues for exercise in hot climatesMost athletes enjoy opportunities forwarm-weather training and competitions, butthese can be challenging for all athletes,especially endurance and team sports athletes.Those who normally live in cold climates willbenefit from a period of heat acclimation beforecompeting in major events held in a hot climate.It is also essential for these athletes to gain heatexperience so that they know how to adapttraining and competition strategies, as well asdrinking behaviours and lifestyle factors whenthey are suddenly exposed to hot weather.40

Cultural andregional issuesathletes’ medical informationAn infinite variety of different food combinationscan be chosen by athletes to meet theirnutritional goals. All the essential nutrientscan be obtained from normal foods, and varietyis a key to meeting nutrient needs, but manydifferent foods can be interchanged. Goodsources of carbohydrate may be bread, rice,pasta, potatoes, couscous or the maize porridgefavoured by many Kenyan athletes. Protein willbe provided by many different foods; theobvious protein-rich foods are meat, fish, eggsand dairy produce, but bread, cereals, pasta,lentils and beans are only a few of the otherexcellent sources of protein. The fruits andvegetables that are commonly available willdiffer from region to region, although manystaples or favourites are exported aroundthe globe. Our eating habits are much moreinternational than they were, and athletescan enjoy foods from different countries ofthe world.

athletes’ medical informationVegetarianconsiderationsMany athletes, often endurance athletes and/orfemale athletes, adopt a vegetarian lifestyle.This personal choice can be very healthy, and isin no way incompatible with success in sport.However, it does mean that athletes must bemore aware of the food choices that they makein order to maintain energy levels, meet trainingand recovery needs, and to support properimmune function.Plant-based, high-fibre diets may reduceenergy availability and athletes should monitorbody weight and body composition to ensureenergy needs are being met.Female athletes may use vegetarianismas a means to restrict calorie intake in order toachieve a desired physique. Female athletesshould seek help from a trusted healthprofessional if they feel out of control withcalorie restriction and/or trying to achieveexcessive leanness. Severe calorie restrictionmay compromise performance as well asreproductive health and bone health.Although most vegetarians meet or exceedtheir protein requirements, plant protein qualityand digestion is decreased and often requiresan intake of approximately 10% more proteinthan if consuming animal proteins. Therefore,protein recommendations for vegetarianathletes are approximately 1.3-1.8 g/kg/dayfrom a variety of plant protein sources. This factmay be of more concern for vegans — thosewho avoid all animal proteins, such as meat,eggs and milk.If there are no animal foods in the diet, thena Vitamin B12 supplement may be necessary.Some vegan food products, such as meatsubstitutes, are B12 fortified — read food labels.Avoiding red meat means that specialattention must be paid to ensuring that the dietcontains enough iron, especially during periodsof rapid growth (e.g., adolescence). Iron intakefrom plant sources should be combined withother foods that aid iron absorption: forexample, iron-fortified breakfast cereals,consumed at a meal containing Vitamin C(a glass of orange juice).Dairy produce should be included in the dietto ensure an adequate calcium intake, but manycalcium-fortified foods are also available.Vegetarian athletes may also be at risk forlow intakes of fat (essential fatty acids areespecially important), riboflavin, Vitamin Dand zinc, which should be monitored andsupplemented in the diet if necessary.There may be special circumstances thatcause athletes to change their normal trainingand dietary habits. Muslims must avoid foodand fluid intake during daylight hours duringthe holy month of Ramadan. This can meanchanges to training times, especially in very hotweather, to ensure that adequate hydration ismaintained. Where athletes must competeduring Ramadan, they should be aware thatprior preparation is necessary to ensure goodliver and muscle glycogen stores and goodhydration. Performance will not necessarilysuffer if the athlete is well prepared.Athletes with special nutrition needs mayface challenges when travelling away fromhome for long periods as the foods they are42

accustomed to may not be easily available.However, with today’s multi-cultural world, thereshould be no real difficulties with a little forwardplanning. Hotels are usually willing to cater tospecial needs, but need adequate warning toallow them to source foods. Remember thatmany countries do not allow the import of freshfoods and seeking local sources is usually thebest option.Ethnic restaurants can be found in almostevery major city of the world and may be aspecial treat for athletes, but these shouldbe checked beforehand. The advice of localathletes may be very useful in identifyingsuitable options.athletes’ medical information

athletes’ medical informationReferencesNutrition for the athlete is based oninformation discussed at the IOC ConsensusConference on Nutrition for Sport, held inLausanne in June 2003. The paperspresented at that meeting were publishedas a Special Issue of the Journal of SportsSciences (Volume 22, No 1, January 2004)1. Energy balance and body composition insports and exerciseAnne Loucks2. Carbohydrates and fat for training andrecoveryLouise Burke, Bente Kiens, John Ivy3. Pre-exercise carbohydrate and fat ingestion:effects on metabolism and performanceMark Hargreaves, John A Hawley, Asker EJeukendrup4. Fluid and fuel intake during exerciseEd Coyle5. Fluid and electrolyte needs for preparationand recovery from training and competitionSusan Shirreffs, Samuel Cheuvront,Lawrence Armstrong6. Protein and amino acidsKevin Tipton, Bob Wolfe7. Dietary antioxidants and exerciseScott Powers, Keith C DeRuisseau, JohnQuindry, Karyn L Hamilton8. Dietary supplementsRon Maughan, Doug King, Trevor Lea9. Exercise, nutrition and immune functionMike Gleeson, Bente Pedersen, DavidNieman10. Nutritional strategies to influenceadaptations to trainingLawrence Spriet, Marty GibalaCommentaries1. Protein and amino acid requirementsof athletesD Joe Millward2. Exertional HyponatraemiaLawrence E Armstrong44

athletes’ medical informationThis booklet has been substantially updatedand revised (February 2010) and has reliedin part on the information presented at the2005 FIFA Consensus Conference onNutrition for Football, published in theJournal of Sports Sciences (Volume 24,No 7, July 2006) and the IAAF ConsensusConference on Nutrition for Athletics,published in the Journal of SportsSciences (Volume 26, 2008).45

athletes’ medical informationIOC Consensus Statementon Sports Nutrition 2003The amount, composition and timing of foodintake can profoundly affect sportsperformance. Good nutritional practice will helpathletes train hard, recover quickly and adaptmore effectively with less risk of illness andinjury. Athletes should adopt specific nutritionalstrategies before and during competition to helpmaximise their performance. Athletes willbenefit from the guidance of a qualified sportsnutrition professional who can provide adviceon their individual energy and nutrient needsand also help them to develop sport-specificnutritional strategies for training, competitionand recovery.A diet that provides adequate energy fromthe consumption of a wide range of commonlyavailable foods can meet the carbohydrate,protein, fat and micronutrient requirements oftraining and competition. The right diet will helpathletes achieve an optimum body size andbody composition to achieve greater successin their sport. When athletes restrict their foodintake, they risk nutrient deficiency that willimpair both their health and their performance.Careful selection of nutrient-dense foods isespecially important when energy intake isrestricted to reduce body and/or fat mass.Fat is an important nutrient and the diet shouldcontain adequate amounts of fats.Athletes should aim to achieve carbohydrateintakes that meet the fuel requirements of theirtraining programs and also adequately replacetheir carbohydrate stores during recoverybetween training sessions and competition. Thiscan be achieved when athletes eatcarbohydrate-rich snacks and meals that alsoprovide a good source of protein and othernutrients. A varied diet that meets energy needswill generally provide protein in excess ofrequirements. Muscle mass is maintained orincreased at these protein intakes, and thetiming of eating carbohydrate and proteinmay affect the training adaptation.A high carbohydrate intake in the daysbefore competition will help enhanceperformance, particularly when exercise lastslonger than about 60 minutes. Dehydrationimpairs performance in most events, andathletes should be well hydrated beforeexercise. Sufficient fluid should be consumedduring exercise to limit dehydration to less thanabout 2% of body mass. During prolongedexercise the fluid should provide carbohydrate.Sodium should be included when sweat lossesare high, especially if exercise lasts more thanabout 2 hours. Athletes should not drink somuch that they gain weight during exercise.During recovery from exercise, rehydrationshould include replacement of both waterand salts lost in sweat.Athletes are cautioned against theindiscriminate use of dietary supplements.Supplements that provide essential nutrientsmay be of help where food intake or foodchoices are restricted, but this approach toachieving adequate nutrient intake is normallyonly a short-term option. The use ofsupplements does not compensate for poorfood choices and an inadequate diet. Athletescontemplating the use of supplements and46

athletes’ medical informationsports foods should consider their efficacy, theircost, the risk to health and performance, andthe potential for a positive doping test.Excessive training and competition areassociated with some negative consequences.Robust immunity and reduced risk of infectioncan be achieved by consuming a varied dietadequate in energy and micronutrients, ensuringadequate sleep and limiting other life stress.Attention to dietary intake of calcium and iron isimportant in athletes at risk of deficiency, butuse of large amounts of some micronutrientsmay be harmful. Female athletes with menstrualdisorders should be promptly referred to aqualified specialist physician for diagnosisand treatment.Food can contribute not only to theenjoyment of life but also to success in sport.Lausanne, 18 June 2003