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Nutrition forAthletesA practical guide to eating for healthand performance

Prepared by the Nutrition WorkingGroup of the International OlympicCommittee

Based on an International ConsensusConference held at the IOC inLausanne in October 2010

Revised and Updated in April 2012 by Professor Ron Maughan andProfessor Louise Burke

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Since 1928, The Coca-Cola Company has been a proud supporter of the Olympic Movement. As such, we’ve been privileged to witness some of the greatest athletic

Today, world-class athletes share an unwavering commitment to a balanced nutritional diet and an active, healthy lifestyle. To support you in this regard, The Coca-Cola Company, through our POWERADE brand, has partnered with the IOC Nutrition Working Group and the IOC Athletes’ Commission to create this nutrition brochure for all athletes.

Helping you achieve peak performance is the mission of POWERADE, a refreshing beverage designed to prevent dehydration and the onset of fatigue during exercise.

Your peak performance also depends on a clean and healthy environment, which is one reason Coca-Cola is committed to a vision of “zero waste” through increasingly sustainable packaging and recycling efforts. We’re also reducing our potential climate impacts through leading-edge technologies including our hydrofluorocarbon-free (HFC-free) cooling technologies. And we’ve improved the energy efficiency of our cooling equipment by up to 40 percent since 2000.

On behalf of the more than 700,000 Coca-Cola system associates across 200-plus nations, I congratulate you on your Olympic journey thus far. Everyone at Coca-Cola wishes you the very best as you compete and forge lasting friendships with your fellow Youth Olympians from around the world!

Muhtar KentChairman & CEOThe Coca-Cola Company

Message from Muhtar Kent

OFFICIAL SPORTS DRINK

achievements of the past century.

The IOC and its MedicalCommission are pleased toprovide athletes with this updatedbrochure, developed under theleadership of the IOC ‘Nutrition’

working group, in close collaboration with the IOC Athletes’ Commission.

Its simplicity and reader-friendly layout makethis work a reference for all those who, like theIOC Medical Commission, believe that nutritionis one of the decisive elements in high-levelathletes’ preparations and one of the keyfactors in athletes’ health.

Powerade is the partner of the IOC’s MedicalCommission for this publication and helps us to spread the information in a worldwidecampaign to athletes at all levels.

For all those who, without aspiring to takepart in the Olympic Games, place sport andphysical activity as a top priority, this brochurewill ensure better management of their efforts and preparations.

Patrick Schamasch Former IOC Medical

Director

Foreword by Dr Patrick Schamasch

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Many factors contribute to success in sport,including talent, training, motivation andresistance to injury. When highly talented,motivated and well trained athletes gather forcompetition, the margin between victory anddefeat is usually small. Attention to every detailcan make that vital difference, and nutrition isa key element of the serious athlete’spreparation.

Diet affects performance, and the foods thatwe choose in training and competition willaffect how well we train and compete. Athletesneed to be aware of their nutritional goals andof how they can select an eating strategy tomeet those goals.

Diet may have its biggest impact on training,and a good diet will help support consistentintensive training while reducing the risk ofillness or injury. Good food choices can alsopromote adaptations in muscle and othertissues in response to the training stimulus.

Athletes are all different, and there is nosingle diet that meets the needs of all athletesat all times. Individual needs also changeacross the season and athletes must be flexibleto accommodate 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, but carbohydrate needs will depend on thetraining load and therefore vary from day to dayand across the season. Athletes must be aware offoods that are good sources of carbohydrate 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. The timing and type of proteinare as important as the amount of protein inthe diet. Well-chosen vegetarian diets can meetan athlete’s protein needs.

A varied and wholesome nutrient-rich dietthat meets energy needs and is based largelyon vegetables, fruits, beans, legumes, grains,lean animal meats, oils and carbohydrateshould ensure an adequate intake of allessential vitamins and minerals.

Maintaining hydration is important forperformance. An adequate intake of fluid before,during (where appropriate), and after exercise isespecially important in hot climates. Saltreplacement is important when sweat losses arehigh, but needs vary between athletes.

Athletes are cautioned against theindiscriminate use of dietary supplements, butcareful use of a small number of supplementsand sports foods may benefit some athletes.

Food is an important part of life, and athletesshould enjoy the foods that they eat, confidentin the knowledge that they have made wisechoices.

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, but triesto give practical information that will be ofuse to the serious athlete.

Key messages

Well-chosen eating practices have much tooffer the athlete:

l Fuel to train and perform at the elite levell Optimum gains from the training programl Enhanced recovery between workouts and

between eventsl Achievement and maintenance of an ideal

body mass and physiquel Benefits from the many health-promoting

components of food l A reduced risk of injury, overtraining fatigue

and illnessl Confidence in being well-prepared to face

competitionl Consistency in achieving high-level

competition performancesl Enjoyment of food and social eating

occasions at home and during travel

Despite these advantages, many athletes donot meet their nutrition goals. Commonproblems and challenges include:

l Poor knowledge of foods and inadequate cooking skills

l Poor or outdated knowledge of sports nutrition

l Lack of access to dietitians /nutrition professionals or other credible resources

l Inadequate financesl Busy lifestyle leading to inadequate time to

obtain or consume appropriate foodsl Poor availability of good food choicesl Frequent travell Indiscriminate use of large amounts of

supplements or failure to use evidence-based supplements and sports foods in the appropriate way

The 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 to train hard and ignore thebenefits that follow from good food choices.

Nutrition for Athletes is based on theconclusions of the IOC ConsensusConference on Nutrition for Sport, held inLausanne in October 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 was updated in April 2012in preparation for the London OlympicGames of 2012 to ensure that athletes haveaccess to the latest information.

This revised version of the booklet wasprepared for the IOC MedicalCommission Working Group on SportsNutrition by

l Professor Ron Maughan, UKl Professor Louise Burke, Australia

We thank Dr Patrick Schamasch for hisinsight and comments in the preparationof this booklet.

Nutrition for the elite athlete

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Energy intake sets the “budget” from which anathlete must meet their needs for carbohydrate,protein and fat, as well as the range of foodsthat provide vitamins, minerals and other health-promoting dietary factors. An athlete’s energyrequirements are made up of severalcomponents: baseline metabolic needs (such asthe energy required to support cellularmaintenance, temperature regulation andimmune health), growth, and physical activity.Energy expended in one of these processes isnot available for others, so the diet must providesufficient energy to meet the needs of allessential functions. Physical activity – or in thecase of an athlete, the intensity, duration andfrequency of training sessions andcompetition – will play a strong role indetermining daily energy requirements.

When daily intake of food energy fromcarbohydrate, fat, protein and alcohol is equalto energy expenditure, the athlete is said to bein energy balance.

Energy balance = Energy intake – energyexpenditure

This means there is neither a net loss nor gainfrom the body’s energy stores of fat, proteinand carbohydrate. These energy stores play anumber of important roles related to exerciseperformance, contributing to: l an athlete’s size and physique (e.g. body fat

stores and muscle mass) l function (e.g. muscle mass)l fuel for exercise (e.g. muscle and liver

glycogen stores)

Athletes often want to change their energybalance, either to produce an energy deficit(principally to reduce the size of body fat stores)or to achieve an energy surplus (principally tosupport growth or support the gain of musclemass). This can be done either by altering energyintake, energy expenditure or both components.

However, an important new concept is that ofenergy availability. This is defined as the energythat is available to the body after the energy costof physical activity has been deducted from dailyenergy intake. Energy availability is therefore, theamount of energy that can be expended to lookafter the body’s physiological needs.

Energy availability = Energy intake – Energycost of training/competition

The body can cope with a small drop in energyavailability, but if it becomes too great, this willcompromise its ability to undertake the processesneeded for optimum health and function.

We now recognise that many health andperformance problems commonly seen inathletes are associated with low energyavailability – these include menstrualdisturbances in female athletes, reduced basalmetabolic rate, compromised immunity, poorhormonal function and impaired bone density.

Although any reduction in energy availability hassome effect on the body, researchers have identified a threshold below which theconsequences are particularly harmful. This isusually discussed in terms of an athlete’s Fat Free

Energy needs

Mass (FFM) – i.e. Body mass minus Body fat. Thisthreshold is set at 30 kcal (125 kJ) per kg FFM.Examples of adequate and low energy availabilityare provided in the table below.

There are three situations that are typicallyassociated with low energy availability. l Disordered eating and eating disorders. We used

to think this was the main cause of energy deficiencies, causing some stigma to the situation. Disordered eating requires early intervention and specialist help, but we now know that many athletes can get into situations of low energy availability without this backdrop

l Restricted eating for weight control or loss or body fat. Many athletes undertake such campaigns with the best of intentions and, often, good reasons. However, the degree of energy deficit achieved by reduced energy intake or increased exercise may be too severe for good health. Even when weight loss is undertaken without any problem behaviour or undue stress, trying to achieve it at too fast a rate is likely to lead to unnecessary compromises of health and performance

l Inadvertent failure to increase energy intake sufficiently during periods of high volume training or competition. Some athletes undertake extremely strenuous training or competition programs. Appetite, time for preparing and eatingfood, and awareness of intake are just some of the factors influencing our food intake that may not always keep pace, especially when there is a sudden increase in exercise load. The practicality of eating a high energy intake day after day can be challenging for many athletes. Some may be unaware that they are falling behind in meeting their energy needs, or that it is problematic.

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Tips for maintaining adequate energy availability

Be aware of energy needs and how these might vary over time. Be prepared to scale energy intakeup and down according to the changing energy costs of daily training or competition. Be aware alsoof additional needs for growth. Ideas for achieving a high energy intake are found in the next section.

Take care when there is a change in your food environment – particularly when travelling orwhen changing your home situation. It can take time and a conscious effort to re-establish neweating patterns when opportunities to eat or access to suitable foods are altered.

Do not embark on drastic diets that limit energy intake or food variety. Even when loss of weightor body fat is likely to achieve better health and performance, severe energy restriction is associatedwith unnecessary consequences of low energy availability. Where possible, plan weight lossprograms so that they can be undertaken at a slower and less harmful pace.

If you are developing stress related to food and body image, seek expert help at an early stage.Female athletes should treat an interruption to a normal menstrual cycle as a problem that also

needs early assessment and intervention. If you are unsure about your energy needs and how toachieve them, consult a sports nutrition expert.

Note that the consequences of low energy availability include irreversible loss of bone, as well asimpairment of hormone, immune and metabolic function. It’s not worth it!

Examples of different levels of energy availability

1. High energy availability for growth or gain of body mass

Energy availability Example> 45 kcal Athlete A: 65 kg and 20% body fat(> 189 kJ) FFM = 80% x 65 kg = 52 kgper kg fat free mass (FFM) Weekly training = 5600 kcal (23.5 MJ)

Daily energy intake = 3520 kcal (14.7 MJ)Energy availability = (3520-800)/52= 52 kcal/kg FFM (219 kJ)

2. Adequate energy availability for weight maintenance

Energy availability Example ~ 45 kcal Athlete B: 65 kg and 15% body fat(~ 189 kJ) FFM = 85% x 65 kg = 55 kgper kg fat free mass (FFM) Weekly training = 5600 kcal (23.5 MJ)

Daily energy intake = 3285 kcal (13.8 MJ)Energy availability = (3285-800)/55 = 45 kcal/kg FFM (189 kJ)

3. Reduced energy availability but still adequate for healthy weight loss (or weightmaintenance at reduced metabolic rate

Energy availability Example 30-45 kcal Athlete C: 55 kg and 20% body fat(125-189 kJ) FFM = 80% x 55 kg = 44 kg per kg fat free mass (FFM) Weekly training = 5600 kcal (23.5 MJ)

Daily energy intake = 2340 kcal (9.8 MJ)Energy availability = (2340-800)/44 = 35 kcal/kg FFM (164 kJ)

4. Low energy availability – health implications

Energy availability Example < 30 kcal Athlete D: 55 kg and 25% body fat(< 125 kJ) FFM = 75% x 55 kg = 41 kgper kg fat free mass Weekly training = 5600 kcal (2.35 MJ)

Daily energy intake = 1980 kcal (8.3 MJ)Energy availability = (1980-800)/41 = 29 kcal/kg FFM (120 kJ)

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In many sports, success is influenced by anathlete’s size and shape. Examples include theimportance of being strong and powerful, orsimply big and tall, in some sports. In otherevents, being small and light assists in movingyour body over long distances, up hills or incomplicated twirls and somersaults. Anathlete’s appearance may also be a factor insports that are judged subjectively, or when theathlete is thinking about their public image.Gaining the physique characteristics that areuseful for your sport starts with choosing theright parents – we all get a genetic start to life!But some of these elements can also bemanipulated through diet and training. Mostathletes at some time of their careers set out toalter their body mass, muscle mass or body fatlevels – sometimes all at the same time. Inother cases, athletes need to take special careto support their needs for growth.

The principles of changing body size and shape are:

l Altering energy balance to promote a loss orgain of body tissue – this can be achieved by changing energy expenditure, altering dietary intake or both

l Undertaking the right training to promote muscle development.

Several other factors are important forstaying healthy and achieving successfulperformance outcomes while achievingphysique changes. These include:

l Choosing targets that are achievable and sustainable in view of your genetic blueprint

l Allowing enough time for the targets to be achieved with sensible changes to nutrition and training

l Setting the right time of the sporting season to undertake the changes so that your efforts don’t clash with the goals of optimumcompetition performance. For most athletes, this would mean during the base phases of training

l Avoiding getting too out of shape when injured or on a break between seasons

l Seeking the help of sports nutrition experts who can work with you and your coach to integrate a good nutrition plan into your training program

l Unfortunately, many athletes don’t value or understand the importance of these factors.

Some of the dietary strategies that may beimportant to achieve these goals include l finding ways to reduce energy intake to

assist with loss of body fat, or the preventionof a gain in body fat when training volume isreduced

l finding ways to support the goals of the training needed to increase muscle mass (see protein section)

l finding ways to increase energy intake to support growth and an increase in muscle/body mass.

Useful strategies for reducing or increasingenergy intake are provided below.

Changing body composition: gaining muscle and losing body fat

Strategies for reducing energy intakeand/or reducing body fat levels

Set realistic targets: this is a medium-term goal rather than something to be achievedby next week.

Try to create a small energy deficit – around500 kcal (2 MJ) per day – by reducingenergy intake and/or increasing energyexpenditure. A small but sustained energydeficit over a longer period will promote fatloss rather than sacrificing muscle mass,and will better support training needs andgeneral nutrition goals. Although manyathletes are impatient and like the idea of aquick but drastic weight loss program, theoutcomes for body composition changes andtraining performance are likely to be betterthan with a large deficit. Remember thatadequate energy availability is needed forlong term health.

Seek a sports nutrition expert for anassessment of current eating patterns andwhere small changes can be made. Keepinga food diary of what you really eat can alsohelp to pinpoint habits that should bechanged.

Limit portion sizes at meals rather thanskipping meals altogether

Use well-chosen snacks between meals tomaintain fuel levels for training sessions.Save part of a meal for a later snack, ratherthan eating extra food

Maintain carbohydrate intake to maintainfuel levels for exercise, especially on dayswhen training intensity and quality isimportant

Maintaining a good spread of protein intakeover the day will help to preserve musclemass as well as to make meals and snacksfilling

Use low-fat strategies in choosing foods andwhile cooking or preparing meals

Limit alcohol intake or cut it out altogether –it is not an essential part of the diet. Inaddition, many people lose their goodintentions after a few drinks. It is easy to eatsnack foods, fast foods or other poor foodchoices when you become too relaxed

Make meals and snacks more “filling” byincluding plenty of salads and vegetablesand by taking the higher-fibre option

Include low glycaemic index forms ofcarbohydrate-rich foods (e.g. oats, legumes,dense-grainy breads, berries, apples, etc) toalso help with satiety

Choose nutrient-dense foods so that youcan meet nutritional requirements from alower energy intake

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Strategies for increasing energy intake to support growth or increase in muscle mass

Set a pattern of frequent meals and snacksduring the day rather than simply trying toeat more at meals.

Plan ahead to have suitable foods and drinksavailable wherever your busy day takes you.It can take some creativity to find foods thatare portable and easy to consume when youare “on the run”.

A food record can identify the times in abusy day that aren’t being well used forfuelling up.

Drinks such as fruit smoothies, liquid mealsupplements and fortified milkshakes andjuices can provide a substantial source ofenergy and nutrients that are quick andcompact to consume, and less likely to causegastrointestinal discomfort than bulky foods.

Although it is important to eat fruit andvegetables, and wholegrain cereal foods fortheir nutrient qualities, overeating thesebulky foods can reduce the energy density ofyour diet. It is OK to include options that aremore compact – for example, juices, andsome “white” cereals.

Use opportunities before, during and after anexercise session to consume energy andnutrients. Compact forms of carbohydrateand before and during exercise can addenergy to the day as well as fuel the session.Sweetened dairy products, liquid mealsupplements and fruit smoothies provide acompact source of protein and carbohydrateafter the workout.

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Carbohydrate, once considered the “backbone”of sports nutrition, has become a topic ofdebate and differing opinions. Around theworld, it typically accounts for about half of ourtotal energy intake. In fact, surveys show thatthe best endurance athletes in the world (theKenyan and Ethiopian distance runners)consume diets that are particularly high incarbohydrates. Meanwhile in many Westerncountries, media reports state thatcarbohydrates make us fat and unhealthy andthe most popular diet books are based on lowand moderate carbohydrate eating plans. Manyathletes are now confused.

It is true that sports nutrition experts havecontinued to evolve the recommendations forcarbohydrate intakes for athletes as well as thelanguage used to describe them. A central ideathat hasn’t changed, however, is theimportance of the body’s stores ofcarbohydrate as a source of fuel for themuscle and brain during exercise. In manytypes of sport, low levels of carbohydratestores are a factor in fatigue and reducedperformance. Furthermore, strategies to ensurethat stores are increased result in performanceenhancements. This will play a key role incompetition nutrition.

There are several updates in the way wenow think about carbohydrate needs in the everyday or training diet:

The athlete’s carbohydrate needs are closelytied to muscle fuel costs of their training. Thetraining load changes from day to day, over thevarious microcycles and macrocycles in theperiodised training calendar, and at differentpoints of the athlete’s career. Therefore, thenew message is that rather than having astatic dietary intake, athletes should vary theircarbohydrate intake according to the rise andfall in muscle fuel needs. Some general targetsare suggested, but should be fine-tunedaccording to the athlete’s energy budget andfeedback from how well they are training.

A further refinement is that athletes shouldparticularly target the days where it isimportant to train hard, at high intensity or withhigh quality to ensure that they have adequatemuscle carbohydrate (glycogen) stores to fuelthese goals.

A great way to assist carbohydrate intake totrack with muscle fuel needs is to includeadditional carbohydrate in meals or snacksbefore and after a workout. This means whentraining needs increase, so does carbohydrateintake. Consuming carbohydrate intake duringlengthy sessions will also add to the day’scarbohydrate target as well as specificallyprovide fuel for the workout. Many athletesshould take this opportunity to practisecompetition strategies for eating and drinkingduring the event.

Targets for carbohydrate should be provided interms or grams relative to the athlete’s size(Body mass) rather than as a percentage oftotal energy intake.

Carbohydrates for trainingand recovery

Rather than talk about “high carbohydratediets” and “low carbohydrate diets”, we shouldnow consider carbohydrate availability relativeto the muscle’s fuel needs – is the total intakeand timing of the day’s intake able to meet thefuel demands of a workout (= highcarbohydrate availability), or are carbohydratestores depleted or sub-optimal in comparison tothe muscle fuel demand (= low carbohydrateavailability). The table above shows that verydifferent amounts of carbohydrate may beadequate for different training loads. Thereforetwo athletes could eat the same about ofcarbohydrate, but according to their trainingneeds, one could achieve high carbohydrateavailability whereas the carbohydrate availabilityof the other athlete is low.

Many athletes do some of their trainingsessions with low carbohydrate availability –for example, when they train first thing in themorning without breakfast, when they go for along workout without access to food or asports drink, or when they reduce their energyintake to reduce body fat levels. This may notbe a problem during the base phase of trainingor on days of light training, when trainingintensity and quality is low. In fact, somestudies suggest that doing some trainingsessions in this way provides a good stimulusto the muscle to help it adapt to training. Ofcourse, such strategies need to be periodisedinto the training program so that they don’tinterfere with training intensity.

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Training load Carbohydrate intake targets (g per kg of athlete’s body mass)

Light Low intensity or skill-based activities 3-5 g/kg

Moderate Moderate exercise program 5-7 g/kg/d(i.e. ~1 hour per day)

High Endurance program (e.g. 1-3 hours 6-10 g/kg/dper day of mod-high-intensity exercise)

Very High Extreme commitment (i.e., at 8-12 g/kg/dleast 4-5 hours per day of mod-high intensity exercise)

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When athletes train more than once per dayand sessions are close together, speedyrecovery of the muscle carbohydrate stores isessential. Consuming carbohydrate-rich foodsand drinks soon after the session helps withrapid refueling, since the muscle can’t storeglycogen effectively in the absence ofcarbohydrate intake.

When rapid refueling is needed after a session,target a carbohydrate intake of about 1 g perkg of body mass per hour for the firs.importantthan the amount, and athletes should makechoices based on convenience, palatability,cost, and the contribution these foods canmake to other nutritional goals.

When it isn’t possible to meet thesecarbohydrate targets during the early hours ofrecovery, the presence of protein in recoverysnacks is likely to promote higher rates ofglycogen storage than carbohydrate alone. Thisis useful since post-workout protein intakeaddresses other goals of recovery eating.

During longer recovery periods (24 hours), thepattern and timing of carbohydrate-rich mealsand snacks does not appear to be critical, andcan be organised according to what ispractical 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 in thetotal diet.

Examples of nutrient-rich carbohydrate and protein combinations(contains 50-75 g carbohydrate and 15-20 g protein)

l 500-750ml Low Fat Chocolate Milk l 1-2 sports bars (check labels for

carbohydrate and protein content)l 1 large bowl (2 cups) breakfast cereal

with low fat milkl 1 large or 2 small cereal bars + 200g

fruit-flavoured yogurtl 1 cup baked beans on 2 slices of toast

or on a baked potatol 1 bread roll with cheese or peanut

butter + large bananal 2 cups fruit salad with 200g fruit-

flavoured yogurtl Bagel with thick spread peanut butter

+ 1-2 cups low fat milkl 300g (large) baked potato + low fat

cottage cheese filling + 1-2 cups low fat milk

l 2-3 slices lean meat and veggie pizza l 2 cups breakfast cereal with milkl 400g flavoured yoghurtl 500-750 ml fruit smoothie or liquid

meal supplementl Thick bread sandwich with meat and

salad fillingl 2 cups stir-fry with rice or noodles

and meat

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In many sports lasting longer than 1 hour, thedepletion of carbohydrate stores causesfatigue and a decline in performance over thecourse of the event. By contrast, nutritionstrategies that provide adequate carbohydratecan reduce or delay the onset of thisperformance decline. Strategies include theintake of carbohydrate in the hours or daysprior to the event to ensure muscle and liverglycogen stores are well stocked in anticipationof the fuel needs of the event.

In the absence of muscle damage, the athletecan normalise their muscle glycogen storeswith as little as 24 hours of carbohydrate-richeating and exercise taper.

‘Carbo-loading’Athletes who compete in events lasting longerthan about 90 minutes may benefit from‘carbohydrate-loading’ for a few days prior tothe competition. This strategy involves meetingthe highest targets for carbohydrate intake (9-12 g/kg/d) for 24-48 hours while exercise isreduced to an easy taper, and allows muscleglycogen stores to be super-compensatedabove normal levels. As a result, the athleteshould have fuel to exercise longer at theiroptimal output before they face a performancedecline.

One day example of foods providing 630 g ofcarbohydrate for a carbohydrate loading diet* (for a person weighing 70 kg with an intakeof 9 g/kg carbohydrate).

l Breakfast (150 g) = 2 cups cereal with milk + 250 ml fruit juice + 1 banana + 2 thick slices toast + thick spread of jam

l Morning snack (50 g) = 500 ml soft drink

l Lunch (150 g) = 1 large bread roll + 1 medium muffin + fruit smoothie

l Afternoon snack (50 g) = 200 gflavoured yoghurt + 250 ml fruit juicel Dinner (200 g) = 3 cups cooked pasta

2 cups fruit salad + 2 scoops ice cream+ 500 ml sports drink

l Snack (30 g) = 50 g chocolate or dried fruit

(*note that other foods may be added tothe meal, such as moderate amounts ofprotein foods. Many athletes like to followlow fibre eating over their carbohydrateloading days, to ensure that the gut is freeof bulky fibre on the day of the event)

Carbohydrate for competition

Pre-event meal(1-6 h period before competition)Athletes sometimes find a set of favourite foodsto eat in the hours prior to competition that notonly provide extra energy during the event, butalso feel ‘right’ in terms of curbing hunger,quieting their stomach and being convenient aswell as practical. In sports that do not causefatigue or carbohydrate depletion (e.g.gymnastics, sprinting, ski-jumping, etc), thepre-event meal need not be carbohydrate-focussed. However, in events involving exerciseof longer than 60 minutes, athletes are advisedto use the pre-event meal to top upcarbohydrate stores – especially if the event isin the morning after an overnight fast.

The effect of eating carbohydrate in the hoursbefore exercise is to increase the muscle’s rateof carbohydrate use. Therefore, the pre-eventmeal should contain enough carbohydrate tocompensate for this “priming” of greatercarbohydrate reliance. A carbohydrate intakegreater than 1 g/kg body mass should achievethis goal, and pre-event meals which enhanceperformance in longer events generally providecarbohydrate in the range of 1-4 g/kg.Continuing to consume carbohydrate during theevent helps to sustain fuel availability.

A ‘mistake’ some athletes make is to eat only a small amount of carbohydrate (less than 1 gcarbohydrate per kg body mass) during the 1-6 h period before exercise and then fail toconsume any carbohydrate during exercise.Unfortunately, this serves to make the bodymore reliant on body carbohydrate supplieswithout providing additional resources tosustain this.

Depending on the time of day, the athlete’spreferences and the availability of food, anathlete may choose a range of carbohydrate-rich foods and drinks to make up their pre-evenmeal. The type, timing and amount of foodsshould be practiced until a successful plan isdeveloped.

Five different examples of foods thateach provide 140 g carbohydrate in apre-competition meal* (2 g/kg body mass for a 70 kg person)are:

l 2.5 cups breakfast cereal + milk + large banana

l Large bread roll or 3 thick slices bread + thick spread honey

l 2 cups boiled rice + 2 slices breadl 4 stack pancakes + ½ cup syrupl 60 g sports bar + 500 ml liquid meal

supplement or fruit smoothie

(*note that other foods may be eaten atthe meal)

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We have long recognised that performance isenhanced when carbohydrate is consumedduring exercise. Benefits include a sustaining ofoptimum pace, greater time spent at highintensities, and maintenance of skills andconcentration. A variety of mechanisms seemto explain this, ranging from the provision ofhigh rates of an additional muscle fuel tomaking the brain feel happy so that it makes usfeel like working harder.

Until recently, we have taken a “one size fitsall” approach to carbohydrate intake duringexercise lasting longer than 60-90 minutes.

However, there is now good evidence thatexercise of different duration and intensitiesrequires a different carbohydrate feedingapproach. A range of carbohydrate-containingdrinks and foods may be able to supply thesetargets, as well as other needs such as fluid.These include special sports products such assports drinks, gels and bars. Many everydayfoods and drinks such as fruit, juices and softdrinks and confectionery may also be suitable.The athlete should practice in training todevelop a race or event fuelling plan. This planwill need to take into account the opportunities provided in the athlete’s event to consume drinks or foods.

Carbohydrate intake during exercise

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Exercise Duration Carbohydrate Commentstarget

During brief l < 45 min Not needed l A range of drinks and exercise sports products can provide

easily consumed carbohydrate

During sustained l 45-75 min Small amounts l Opportunities to consumehigh intensity including mouth foods and drinks varyexercise rinse according to the rules and

nature of each sportl A range of everyday dietarychoices and specialised sports products ranging in form from liquid to solid may be usefull The athlete should practice to find a refuelling plan that suits their individual goals including hydration needs and gut comfort

During endurance l 1-2.5 h 30-60 g/h l As aboveexercise including l Higher intakes of carbohydrate“stop and start” are associated with bettersports performance

l Products providing multiple transportable carbohydrates (Glucose: fructose mixtures) will achieve high rates of oxidation of carbohydrate consumed during exercise

During l > 2.5-3 h Up to 90 g/h ultra-endurance exercise

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Protein needs in sport are another area in whichknowledge and practice have evolved. Very earlybeliefs included the need for high proteinintakes or the specific consumption of meatfrom animals with favourable characteristics forsport (e.g. speed, strength, courage etc). Abelief in the benefits of a high protein intake hascontinued in strength/power sports, althoughthere is generally a shared emphasis betweenprotein-rich foods and specialised proteinsupplements. For many years there has beendebate about the total protein requirements ofathletes, with many experts believing that dailyneeds are elevated above those of sedentarypeople, but easily achieved within the energyintakes consumed by most athletes. Proteinintake targets for both strength and enduranceathletes have been set at about 1.2-1.6 g/kgbody mass per day. Dietary surveys show thatmost athletes easily meet these goals, evenwithout the intake of expensive supplements.Athletes who are most at risk of failing to meetthese targets are those who restrict their energyintake and food variety.

The new way to consider protein needs,however, is to consider its role in promoting theoutcomes of training – and in particular, theway the body adapts to the type of exerciseundertaken in each workout. The response totraining is specific to the stimulus andproportional to the training load. Every athleteknows that strength training is very differentfrom endurance training, and the result is thatthe muscle makes more of the specific proteinsit needs to cause the muscle to perform better.Dietary protein plays an important role in this

response to exercise. The amino acids thatmake up the proteins in the foods that we eatare used as the building blocks for themanufacture of new tissue, including muscle,and for the repair of damaged tissue. They arealso the building blocks for hormones andenzymes that regulate metabolism, support theimmune system and other body functions.Protein provides only a small source of fuel forthe exercising muscle.

When this approach to protein needs istaken, the focus becomes how to promoteoptimum protein synthesis in the period ofrecovery and adaptation from each workout.The following ideas have emerged:

Eating a source of high quality protein soonafter exercise is part of the process ofpromoting muscle protein synthesis. Highquality protein, particularly from animalsources (e.g. dairy, meats, eggs etc) isespecially valuable.

The amount of protein required to maximisethis response to exercise is quite modest –about 20-25 g. Greater amounts of proteinthan this are simply burned as fuel.

It may help to choose a protein source thatis rapidly digested as the post-workoutprotein boost. Whey protein fits this profile,which explains its popularity for post-workout recovery. This can easily be found ineveryday dairy foods and drinks.Nevertheless, sometimes there can be valuein using a more compact form that is easy to

Dietary protein for athletes: from requirements to optimum adaptation

carry and prepare around the exercisesession – such as a liquid meal supplementor a simple protein powder. There is nojustification for the more expensive proteinpowders or amino acid formulations with extraingredients and fancy claims.

We know that the muscle is stimulated toincrease its protein synthetic rates for up to24 hours after a workout. How best toorganise our protein intake over the day toutilise this is still unknown. It makes sense,however, to spread protein over the meals andsnacks consumed over the day. This is notsomething that our traditional eating patternsalways achieve, since most people eat themajority of their protein intake at the eveningmeal. It may be more sensible to redistributeprotein intake to other meals in the day.

Protein rich foods: 10 g protein is provided by:

l 2 small eggsl 300 ml cow’s milkl 20 g skim milk powderl 30 g cheesel 200 g yoghurtl 35-50 g meat, fish or chickenl 4 slices bread – 90 g breakfast cereall 2 cups cooked pasta or 3 cups ricel 400 ml soy milk – 60 g nuts or seedsl 120 g tofu or soy meat – 150 g

legumes or lentilsl 200 g baked beans – 150 ml fruit

smoothie or liquid meal supplement

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Athletes generally appreciate the need to drinkbefore, during and after exercise and theimportance of sometimes using drinks thatcontain added carbohydrate and salts. Someathletes, however, do not drink enough whileothers drink too much so it is important to learnthe practical aspects of: a) when it may behelpful to drink during exercise b) how much todrink, c) what type of drinks are best, and d)what modifications should be made in hot orcold environments.

Just as general training and competitionstrategies should be tailored for individualathletes in accordance with their uniqueneeds and preferences, so should theirdrinking and eating choices during exercise.Athletes, coaches and trainers should ‘finetune’ these recommendation to identify theirown winning formula.

When is helpful to drink during exercise?Fluids consumed during exercise can play anumber of roles. These include making theathlete feel more comfortable, replacing a bodyfluid deficit, and providing a means to consumeother ingredients. The importance of each ofthese roles will vary according to the situation.

It is seldom necessary to drink during exercisethat lasts less than about 40 minutes, but someathletes feel better after rinsing the mouth withcool drinks and this should do no harm.

Meanwhile, during training or competitionssessions lasting longer than this, there may beopportunities and advantages to drinking during

the session. When it is not possible to drinkduring ‘heavy sweating’ type exercise lastinglonger than 30 min, an alternative is to hydratewell just before starting the session. The athleteshould practise drinking during the 15 minutesbefore exercise and find how much is initiallyfilling but comfortable once exercise begins(e.g., 300-800 ml).

How Much to Drink?Sweating causes a loss of water and salts fromthe body, but water is also continually lost in thebreath and through the skin even though theselosses may not be obvious. Small losses ofwater have no effect on performance, butsevere dehydration is harmful to performance.There is no clear evidence on the point at whichperformance begins to be affected and thisalmost certainly varies between individuals aswell as depending on the type and duration ofexercise and on the environmental conditions.

Athletes are often advised to drink only whenthirsty, but this may not always be a reliableguide. Furthermore, the rules and opportunitiesto drink fluids in many sports may not coincidewith the times that thirst hits. A more targetedoption is to develop a fluid plan to fit the sport,the individual and other nutritional needs. As astarting point, the athlete should try to drink ata rate that replaces enough of their sweatlosses so that the overall fluid deficit for atraining session or competition is kept to nomore than about a 2% loss of body mass (i.e.1.0 kg for 50 kg person, 1.5 kg for a 75 kgperson, and 2 kg for a 100 kg person). In warmenvironments, dehydration and exercise

Water and salt needs for training, competition and recovery

intensity interact to increase the risk ofimpaired performance and heat illness. Whenrates of sweat loss are very high, it isn’t alwayspractical to drink enough to keep fluid deficitsbelow this target. A more feasible alternative issimply to try to minimize dehydration.

In some situations, athletes over-hydrate duringexercise – drinking more than their sweatlosses. There may be some reasons when this isjustified; for example, the case of the athletewho starts a workout or event alreadydehydrated. However, problems can occur whenthe fluid intake is excessive, leading to a seriousproblem called hyponatraemia (dilution of bloodsodium concentrations). This is most often seenin recreational exercisers who work at lowintensities but drink large volumes of fluid in thebelief that they are doing the right thing.

In all of these situations, it can help for anathlete to have a feel for their typical sweatrates and how hard or easy it is to drink tokeep pace with these. The guide belowprovides some ideas on to how to check this.

When do you need more than water?Although hydration is a key focus of nutritionstrategies during exercise, fluids consumedduring exercise can contain a range ofingredients. In terms of proven performancebenefits, no nutrients match water and/orcarbohydrate.

During exercise lasting longer than 1 hour andwhich elicits fatigue, athletes are advised toconsume a source of carbohydrate that is

rapidly converted to blood glucose. Thisgenerally improves performance – allowing theathlete to maintain pace, skills andconcentration instead of succumbing to fatigue.As outlined in the earlier section onCarbohydrates in competition, the targets forcarbohydrate during exercise will vary accordingto the athlete’s preparation (how well fuelled),the fuel needs of the event (duration andintensity of the session) and individual tolerance.

The use of commercial sports drinks with acarbohydrate content of about 4-8% (4-8g/100 ml) allows carbohydrate and fluid needsto be met simultaneously in most events. Thiscarbohydrate can come from sugars (i.e.,sucrose, fructose, glucose), maltodextrins orother rapidly digestible carbohydrates. It is bestfor athletes to stick to well-known sport drinkswith which they are familiar to avoidgastrointestinal distress or otherconsequences. Some athletes can toleratemore concentrated drinks, especially if thesecontain mixtures of sugars. Practising withthese drinks in training will help the gut tocope better during competition.

Typically, when carbohydrate is consumedduring exercise, it is best consumed in apattern of frequent and continued intake. Thiswill provide a constant stimulation of the brainand central nervous system, or when needed, aconstant source of additional fuel for themuscle.

Sodium should be included in fluids consumedduring exercise lasting longer than 1-2 hours or

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by individuals during any event that stimulatesheavy sodium loss (i.e., more than 3-4 gramsof sodium, see next page for assessment).

Caffeine contained in commonly availablebeverages and foods can enhance enduranceor performance during the later stages ofprolonged exercise. This benefit can beobtained with relatively small doses of caffeine(about 2-3 mg/kg body mass or 100-200 mgcaffeine). This is equivalent to 1-2 cups ofbrewed coffee or 750-1500 ml of a colabeverages as commonly consumed by peopleof various cultures. Various sports products(gels, drinks etc) may also provide a convenientlow dose serve of caffeine.

Rehydration after exerciseReplacement of water and the salts lost insweat is an essential part of the recoveryprocess. Since sweat and urine losses continueto occur during recovery, the athlete will needto drink about 1.2-1.5 litres of fluid for each kgof weight loss in training or competition tocompensate and fully restore fluid losses.

Sodium, the main salt lost in sweat, also needsto be replaced. Sodium replacement can beachieved via sodium-containing fluids such assports drinks and pharmacy oral rehydrationsolutions. However, simply a meal or snack cansupply the salt that is needed. This may bebecause the foods are salt-containing (e.g.breads, breakfast cereals, cheese, processedmeats) or because salt is added in thepreparation or serving of the meal.

Recovery after exercise is part of thepreparation for the next exercise session, andrehydration should be considered as animportant part of the equation.

Special strategiesAthletes who have dehydrated to make weightwill need special strategies for drinking beforeand during competitions to optimiseperformance. These athletes will benefit fromthe advice of a qualified and experienced sportsnutrition professional.

Athletes training and competing whilepractising fasting during the month of Ramadanmust rehearse a hydration strategy thatpreserves performance and protects health.

Just like new shoes, don’t try out newplans for fluid and fuel intake duringimportant competition. Do it in practiceand find what fits you best.

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Severe 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. Three simple steps may help to guideyour hydration practices

1. Start the session 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.

Note that the aim should NOT be for your urineto be as pale as possible. Drinking too muchcan be uncomfortable and, if excessive, possibleharmful. The aim is to develop fluid practicesover the day that keep pace with regular fluidneeds and special losses from exercise or hotenvironments. As losses change, so shoulddrinking practices. It makes since to spread fluidintake over the day rather than trying to playcatch up at the end. Drinking more than youneed in the late part of the day can meaninterrupted sleep due to toilet breaks.

2. Develop a drinking plan for training andcompetition that is right for you. This should bebased on several pieces of informationincluding your typical sweat losses, theopportunities to drink in your sport, andfeedback from comfort and thirst.

Monitor your sweat losses and the success ofyour drinking plan during training sessions indifferent situations (see box). How did you feel?How did you perform? What was your weightloss over the session? This should generally notexceed about 1-2% of body mass. If you lostmore than this, you probably did not drinkenough. Drink more next time. If you lost less,you might have drunk too much. Did it makeyou feel uncomfortable? Did you take time outto drink that was unnecessary?

Drinking so much that you gain weight dur ingcompetition is never likely to be a good idea.The only time you might need to do this iswhen you have been dehydrated at the start ofthe event.

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 may be a contributing factor insome cases of muscle cramp. Sports drinkswith higher salt (sodium) levels (e.g. 300-500mg sodium per 500 ml liquid) may help reducethe risk of cramps.

Practical ways to assessand manage hydration

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How to estimate sweat losses and sweat rates:

1) Measure body mass both before and after at least one hour of exercise underconditions similar to competition or a hard practice.

2) Take these body mass measurements wearing minimal clothing and while bare footed. Towel dry after exercise and obtain body mass as soon as is practical after exercise

(e.g. less than 10 min, and before eating, drinking or going to the toilet).

Example: Pre-exercise weight = 74.5 kgPost-exercise weight = 72.8 kgFluid deficit = 1.7 kg

3) Estimate the weight of any fluid or foods you have consumed during the workout

Example: 800 ml of fluid = 800 g or 0.8 kg).

4) Sweat loss (Litres) = Body mass before exercise (in kg) - Body mass after exercise(kg) + weight of fluids/foods consumed (kg).

Example: 74.5 kg – 72.8 kg = 1.7 kg deficit+ 0.80 kg (800 ml fluid) = sweat loss of 2.5 kg or 2500 ml.

To convert to a sweat rate per hour, divide by the exercise time in minutes and multiply by 60.

5) Your weight deficit at the end of the session provides a guide to how well youhydrated during the session, and how much you need to rehydrate afterwards.

To convert kg to % body mass, divide the weight deficit by starting body mass and multiply by 100:

Example: 1.7 kg/74.5 X 100 = 2.3%

Note: 2.2 pounds equals 1.0 kg and converts to a volume of 1.0 litre or 1,000 ml or 34 ounces of water.

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Ruby Brown

Mid Brown

Orange Brown

Copper Brown

Rich Golden Amber

Amber

Pale Amber

Golden Orange

Golden Yellow

Straw

Pale Yellow

11

10

9

8

7

6

5

4

3

2

1

Use this chart (left) tocheck your urine colour. If the colour is dark, youmay need to drink more.

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Vitamins and minerals are chemicals that helpthe body to function smoothly by acting as co-factors in metabolism. Some vitamins andminerals also have a role as antioxidants tomop up the free oxygen radicals that areformed as a by-product of metabolism. Otherminerals form important tissues such as thecalcium in bones. In short, they are importantfor maintaining optimum health and function.Athletes often want to know if their trainingprograms create special needs for additionalintakes of vitamins and minerals. It is likely thatthis might be the case for at least somenutrients, but a well-chosen diet based onadequate energy intake can easily meet anyincreased demands.

Dietary surveys show that most athletesare well able to meet the recommendedintakes for vitamins and minerals by eatingeveryday foods, such as fruits, vegetables,whole grains, lean dairy and meats. Thoseat risk of sub-optimal intakes of thesemicronutrients include:

l athletes who restrict their energy intake,especially over long periods to meet weight lossgoals l athletes who follow eating patterns withrestricted food variety and reliance on foodswith a poor nutrient-density

The 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 limited

food supply - or if an individual is found to besuffering from a lack of a particular vitamin ormineral, then short-term supplementation maybe 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.

There are some special micronutrients andother food chemicals that merit special mentionand discussed below.

Antioxidant nutrientsWe know that free oxygen radicals areproduced during normal metabolism, and thatour body develops antioxidant defence systemsto neutralise these chemicals and the damagethey can cause. We also know that exercisecauses an increased production of theseradicals, and many athletes feel that antioxidantsupplements may help to protect them againstthis elevated level of harm. Vitamins C and Esupplements have been popularly used for thispurpose.

More recently, however, there have beenchanges to such thinking.

It seems unnecessary to provide large doses ofa few antioxidant vitamins when the body hasits own mechanisms to increase a morecomplex antioxidant defence system. In fact,supplementation may unbalance the systemand cause more harm than good.

Vitamins, minerals and phytochemicals

There may be some benefits associated withthe production of free oxygen radicals – newevidence shows that they function as signals topromote important adaptations to training. It ispossible that the use of antioxidantsupplements may actually neutralise some ofthe signalling that underpins recovery andadaptation to a workout, which means thatantioxidant supplementation could reduce theeffectiveness of a training program.

Foods contain a large variety of healthpromoting chemicals in addition to vitamins andminerals. These products – usually calledphytochemicals or phytonutrients – promotefunction and health in our body as antioxidants,anti-cancer agents, and many other roles. Thenames of some of the chemicals includequercetin and ECGC., New studies arecontinually investigating whether supplementalforms of these products could be useful forhealth and performance. To date, these studieshaven’t been able to translate the potent healthbenefits known about these products into afunctional output. Therefore, at present, themost effective way to approach thesechemicals is though eating them in plentifulamounts in food.

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Ideas for promoting dietary variety andnutrient-rich eating to achieve aplentiful intake of vitamins, mineralsand phytochemicals:

Be open to trying new foods and newrecipes and make the most of foods inseason.

Explore all the varieties of different foodssuch as different types of fruits, vegetablesand grains

Mix and match foods at meals, such assalads and soups.

Think carefully before banishing a food orgroup of foods from your eating plans.

Find substitution foods that have similarnutrients when excluding a food groupfrom your diet.

Include fruits and/or vegetables at everymeal and snack. The strong and brightcolours of many fruits and vegetables area sign of a high content of various vitaminsand phytonutrients. Aim to fill your platewith a rainbow of highly coloured foods toensure a good intake of these health-promoting dietary compounds.

Vitamin DVitamin D is classified as a fat-soluble vitaminwhich acts as a hormone. It has importantfunctions in the body including maintenanceof good bone health, muscle function andimmunity. Vitamin D is found in some foods,but our major source comes from sunshineexposure. There is evidence that many peoplehave deficient or sub-optimal vitamin Dstatus. Vitamin D deficiency can lead toseveral health issues including increased riskof bone injuries, chronic musculoskeletal painand viral respiratory tract infections. Reversalof sub-optimal vitamin D status in athletesmay have beneficial effects on athleticperformance and health.

Athletes at risk of vitamin D deficiencyinclude those who have the followingcharacteristics:

l train indoorsl have dark skinl live further away from the equatorl wear clothing that covers most or all of their

bodyl regularly use sunscreen or consciously avoid

the sun

Such athletes should be screened for poorvitamin D status and if levels are sub-optimal, acourse of vitamin D supplementation, andperhaps judicious, sunshine exposure should beundertaken under medical supervision.

IronIron plays an important role in the transport ofoxygen in the blood (as haemoglobin) andmuscle (as myoglobin), and inadequate ironstatus can obviously impair performance andrecovery. There is some evidence that anathlete’s iron requirements may be elevateddue to increased levels of loss due to theirtraining load. However, most athletes whobecome iron deficient or anaemic do sobecause of poor iron intake. Athletes who are athigh risk of such problems are those whorestrict energy intake and dietary variety. Sincemeats, including fish and poultry, are a majorsource of well absorbed iron, vegetarian eaterswill need to plan their meals carefully to findalternative iron sources. Females are also atrisk because of increased iron requirementsdue to menstrual blood losses matched againsta smaller food intake. Iron-rich eating will helpto reduce this risk. Athletes who are at risk ofpoor iron status should be monitoredperiodically. Athletes who are undertakingaltitude training also need to have iron statusmonitored to ensure they have sufficient ironstores to allow the adaptations to theirspecialised training demands. Routine use ofiron supplements is not recommended: toomuch iron is just as harmful as too little. Self-medication with iron supplements may notaddress the real causes of an athlete’s fatigueor other issues of poor eating.

Iron rich eating strategies.Consume moderate servings of red meats(well-absorbed iron) in 3-5 meals per week.

Choose iron-fortified cereal products suchas breakfast cereals.

Combine plant and non-meat sources ofiron (e.g. legumes, cereals, eggs, greenleafy vegetables) with food factors thatenhance iron absorption.

These include vitamin C and an ironenhancing factor found in meat/fish/chicken.Examples of clever matching include fruitjuice or fruit with breakfast cereal, or chillicon carne (meat and beans).

CalciumCalcium is important for healthy bones,especially in adolescents and in femaleathletes, so it is important to ensure adequatecalcium intake. The best sources of calcium aredairy foods, including low fat varieties.

Calcium rich eating strategies.

Each athlete should aim to include atleast 3 servings of these foods in theirdaily eating plans:

l glass of milk l slice of cheese l carton of yoghurt.

Additional daily servings are required duringgrowth spurts in childhood and adolescence,and for pregnancy and lactation

Calcium fortified soy foods may provide auseful substitute when an athlete cannotconsume dairy foods.

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Athletes look to sports foods and nutritionalsupplements for many benefits, includingthose listed below

l promoting adaptations to trainingl increasing energy supplyl allowing more consistent and intensive

training by promoting recovery between training sessions

l maintaining good health and reducing interruptions to training due to chronic fatigue, illness, or injury

l enhancing competitive performancel providing a convenient source of nutrients

that are easy to consume when everyday foods are unavailable or impractical to eat. This is most often the case just prior to, during, or after an exercise session.

Sports foods are generally manufactured toachieve the last of these goals. Byproviding a practical way to meet specialnutrition needs they may indirectly assistthe athlete to achieve some of the benefitson the list. Examples of useful sports foodsinclude:

l sports drinks (providing fluid, electrolytes and carbohydrate during exercise)

l sports gels (additional carbohydrate intake, especially during exercise)

l liquid meals (carbohydrate, protein, vitamins and minerals for a pre-event meal, post-exercise recovery or a high-energy diet)

l sports bars (carbohydrate, protein, vitamins and minerals – often a solid form of the liquid meal)

Of course, the cost of these sports foods mustbe considered before using them. Athletesshould recognise that the sports food marketincludes products that are carefullymanufactured to provide nutrients to meetwell documented goals right through togimmicky items that have a poor compositionor the addition of ingredients with a poorevidence base.

The use of pills, potions, powders and othersports supplements is widespread amongathletes, but few products are supported bysound research and some may even beharmful to the athlete. Athletes should carefullyexamine the risks and rewards of individualsupplements before using them.

Where there is a demonstrated deficiency of anessential vitamin or mineral, and an increasedintake from food is not possible, a supplementmay be h. For example, other sections of thisbooklet have noted that athletes with adiagnosed deficiency of iron or vitamin D maybenefit from a course of supplements, but thisshould be done only if a blood test shows it tobe necessary. The use of supplements,however, does not compensate for poor foodchoices and an inadequate diet. A much betteroption is to learn about nutrition and foods sothat you can choose foods to ensure that yournutritional needs are met. A well-chosen dietwill promote an adequate intake of theessential vitamins and minerals.

Supplements andsports foods

Protein powders and supplements

Protein supplements, high protein bars andamino acid preparations are among the biggestselling sports nutrition products. An adequateintake of protein is essential for muscle growthand repair, but this can usually be achievedfrom everyday foods and expensivesupplements are seldom required. When thereis a case for a more practical source of highquality protein, the preferred proteinsupplements are listed below:

Protein-carbohydrate supplements (known also as liquid meal supplements). These provide an easily prepared and rapidly digested source of the major nutrients needed for recovery after exercise (helping with repair, rehydration and refuelling). In addition, they can provide an easily consumed source of energy or help meet energy and nutrient needs while travelling.

A simple whey protein powder; whey, is a high quality milk protein, that provides a rapidly digested source of leucine and other essential amino acids. A whey protein powder may be useful when repair and adaptation is the main recovery need, or when a quick fix is needed to add quality protein to a sub-standard meal. There is no evidence that fancy versions of whey protein,with special preparation techniques or other ingredients, are superior to simpler products.A serving that provides 20-30 g of whey protein is adequate to meet needs at a single meal or snack.

Fat reduction and muscle building

A huge array of supplements, claiming toreduce body fat levels and build bigger andstronger muscles – appeal to athletes and non-athletes alike.

The reality is that most products that areeffective in doing increasing lean tissue anddecreasing body fat are either on the bannedlist or are associated with serious health risks(or both). Many weight-loss supplements havebeen shown to contain prohibited drugs thatare not listed on the label, which can lead tofailed drug tests.

Compounds in the muscle building categoryinclude chromium, boron,hydroxymethylbutyrate (HMB), colostrum andothers. Based on current research, none ofthese has anything worthwhile to offer theathlete.

Increasing energy supply

Supplements in this category include pyruvateand ribose as well as some more exotic herbalpreparations. None of these products is likely toimprove performance and, in spite ofadvertising claims, none is supported by goodindependent evidence. One exception to thisrule may be carnitine. There is now limitedevidence that carnitine can affect exercisemetabolism in some circumstances, but theevidence for performance effects is not yetconvincing.

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Nutrition and the immune system

There 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 levels ofstress hormones reduce its ability to fight theseinfections.

Many nutrition supplements, includingglutamine, zinc, echinacea, colostrum andothers, claim that they can boost the immunesystem, but there is no strong evidence thatany of these products are effective. The beststrategies to support a healthy immune systeminclude scheduling appropriate rest periods,and matching energy and carbohydrate intaketo fuel needs. There is good evidence thatcarbohydrate intake during prolonged exercisereduces the release of stress hormones. Thereis also evidence that probiotics, such as thelactobacillus found in yoghurts, may also assistgut health and the immune system.

Supplements for bone and joint health

Hard exercise training puts extra wear and tearon the bones, joints and associated structures,and numerous supplements are claimed toprotect and repair these tissues.Healthy bones need a good supply of calcium,magnesium, phosphorus, Vitamins D and C andprotein. In most cases these nutrients can besupplied by a well-chosen diet and appropriatesunshine exposure. Athletes who suffer fromproblems related to sub-optimal bone densityshould seek professional advice and supervisedtreatment from a sports physician.

Glucosamine, chondroitin,methylsulphonylmethane (MSM) and otherproducts are promoted for joint health. There issome evidence that long-term (2-6 months)glucosamine treatment can provide subjectiverelief in elderly individuals suffering fromosteoarthritis, but evidence is lacking for abenefits such as a “joint protective” effect fromhigh-intensity training in healthy athletes.

Supplements that might work

Some supplements do offer the prospect ofimproved performance for some athletes inspecific events. These supplements includecreatine, caffeine, bicarbonate, β-alanine andperhaps a very few others.

Creatine. Creatine supplements can increasethe amount of high energy phosphocreatinestored in the muscles, and may improveperformance in single or multiple sprints.Supplementation may also lead to gains instrength and/or muscle mass, which is helpfulfor some athletes but the extra weight may beharmful for others. As with all supplements,exceeding the maximum effective dose is nothelpful. Creatine is normally found in meat andfish, but the effective doses (10-20 g per dayfor 4-5 days to load, and then 2-3 g per day formaintenance) are more than is found in normalfoods. Creatine supplementation does notappear to be harmful to health.

Caffeine. A small amount of caffeine (1-3mg/kg) can help performance in prolongedexercise and may also be helpful in exercise ofshorter duration. Such moderate doses can befound in everyday amounts of coffee, coladrinks and some sports products (e.g. gels). Forexample, 100 mg of caffeine is supplied by asmall cup of brewed coffee or 750 ml of a coladrink. Larger doses of caffeine do not seem tobe more effective, and may have negativeoutcomes such as anxiety, gastrointestinaldistress, over-arousal and poor sleep patterns.This is likely to be a problem in multi-dayevents and in sports involving heats and finals.

Energy Drinks. These sugary caffeinateddrinks should not be confused with sport drinksthat are designed to rehydrate the body duringexercise. In fact, energy drinks are a poorchoice to consume when exercising (especiallyin the heat) due to high sugar content that canimpair fluid absorption. While energy drinksmay seem refreshing and hydrating, theyshould not be consumed before, during, or afterexercise when you need to replace sweat loss.These drinks may also be potentially dangerousif used in excess or in combination with otherstimulants or alcohol. Lastly, energy drinks maybe tainted with prohibited substances, such asthose derived from unregulated herbals. Mostdrinks are not tested for purity orcontamination, and could lead to a positivedoping test.

Buffering agents. During very hard exercise,the muscles produce lactate and hydrogen ions(acidity). This is both good (giving energy toallow hard efforts) and bad (causing pain andinterfering with muscle function). In the sameway that excess stomach acidity can beneutralised by taking bicarbonate, so can takingsodium bicarbonate in a dose of about 0.3 gper kg body mass before an event provide theblood with extra capacity to buffer the acidityproduced by the muscle. This can reduce thefatigue and performance decline seen in all-outevents lasting from about 30 seconds to 8minutes, and perhaps in team games in whichthere are repeated efforts of this nature.

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There is a risk of gastrointestinal problems, andathletes should experiment in training. Sodiumcitrate is another buffering agent, but appearsless effective. More recently, chronic intake ofβ-alanine supplement over 4-10 weeks hasbeen shown to increase muscle levels ofcarnosine, an important buffer. There is someevidence that this might improve performancein some high intensity exercise models, butfurther work is required to be sure of the rangeof situations in which it might be useful. Insome events there may be benefits fromcombining β-alanine supplementation (internalmuscle buffer) and bicarbonate loading(external buffer in the blood) to maximisebuffering potential.

Nitrate. Short-term supplementation withnitrate may reduce the amount of oxygenrequired to do a set amount of work. Thisincreased efficiency might improveperformance in events lasting a few minutes orlonger. Many vegetables, including beets, arehigh in nitrate; thus, beetroot juice has becomea popular supplement with athletes. Moreresearch is needed to confirm the efficacy ofbeetroot juice/nitrate supplementation onperformance and to determine the range ofevents in which it might be useful. Althoughincreasing nitrate intake through vegetableconsumption is not harmful, the safety of usingnitrate powders is yet to be studied.

Supplements and doping

Athletes who are liable for drug testing undernational or international programs should beespecially cautious about supplement use. Some supplements are prepared in unhygienicconditions and contain toxins that may causegastrointestinal problems. Others do not containsome or all of the ingredients - especially theexpensive ones – that are listed on the label.Contamination of dietary supplements withsubstances that may cause an athlete to fail adoping test is widespread – some surveys havesuggested that as many as one in foursupplements may result in a positive test.These prohibited compounds have not beendeclared on the label, so there is no way for theathlete 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.

Many herbal supplements claim to increasetestosterone levels and hence have an anabolicaction. These supplements include thefollwoing: Tribulis Terrestris; Chrysin; Indole-3-Carbinol; Saw Palmetto; Gamma-oryzanol;Yohimbine; Smilax; Mummio. These claims arebased on studies in test tubes and none havebeen shown to work in humans. Athletes arecautioned against the use of thesesupplements.

Athletes must be aware of the strict liabilityprinciple that makes them responsible foreverything they eat and drink. Ignorance is notan acceptable excuse for a positive dopingresult.

Check all supplements with a medical officer orqualified sports nutrition professional. If there isany doubt at all, don’t take it.

Issues to consider when deciding to use asports food or supplement

l Is it safe?l Is it legal?l Is there evidence that it works at the dose

recommended?l Am I aware of the correct protocols of how

and when to take it?l Can I afford it?

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The young 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 experience working in a teamenvironment. Girls and boys can start practisingand competing at an early age, though thefocus should be on fun and skills developmentrather than performance. Nonetheless, mostchildren are naturally competitive and it wouldbe a mistake to suppress this instinct. Thosewith particular talent may progress to serioustraining and competition, but others continuefor reasons of recreation, fitness or socialcontact.

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 to a progressive programaimed at developing the skills and specificfitness and physique required to progress toserious competition. Talented young athletesmay be invited to train with another age groupor with a senior squad, often in addition to theirinvolvement 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 dietary aims are to minimisethe risk of gastrointestinal upset and to avoidproblems of dehydration on hot days. It may bebest to avoid solid food for 2-3 hours beforecompetition – the combination of exercise andnerves can cause some gastric distress.

Children can often be out in the sun for manyhours on sports days, and adults should bevigilant to ensure frequent application of suncream and be aware of any child who seems tobe having problems. Ample fluid should beavailable, and children may need to bereminded to take small amounts of drinks atregular intervals.

Special issues and eating strategies:Parents are often asked to serve as coachesand trainers of age-group teams. They mayaccept these positions without an appreciationor knowledge of the nutritional needs of thesport or young people, and without anyresources to implement an effective trainingand diet program. It is important that educationresources are made available to these coaches so that they can guide young athletesinto good habits.

Nutrition needs for special populations

Athletes should be encouraged to develop goodnutritional habits at an early age. Adolescenceis a time marked by an increasedindependence, and this extends to greaterfreedom of food choice and responsibility forfood 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 lesseffective 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 includingadequate intake of energy, protein and vitaminsand minerals. 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 and timemanagement skills to fit in all the eatingoccasions required to achieve high energy,nutrient-rich eating.

Although the rate of obesity in children is stillrising, active youngsters and young athletes stillneed a plentiful supply of energy from foods,including nutritious snacks between meals andenergy-containing drinks. A snack before andafter school or afternoon activities will bevaluable in providing extra fuel for the sessionas well as an energy boost during the longperiod between lunch and dinner.

Young athletes have been shown to drink more ofa flavoured drink than water during activity, whichmay be an important consideration for promotingfluid intake, especially if exercise is in the heat.They may also be involved in sports in whichthere are benefits to consuming carbohydrateduring exercise to supply an additional source ofmuscle fuel. Therefore, there may be legitimatebenefits to making sport drinks available to youngathletes during exercise.

After exercise, recovery is promoting by speedyintake of protein, carbohydrate and fluids.Snacks consumed before and after the workoutmay need to be eaten in the car or whiletravelling between activities. However, there aremany portable nutrient-rich choices that can beconsumed “on the run” including sandwiches,cereal and milk, flavoured milk drinks, yoghurtand other dairy foods, fruit and dried fruit/nutmixes. It is not always possible to findappropriate choices at sporting venues, so it iswise to plan ahead. Many children andadolescents are not aware of their hunger untilthey become fatigued or suddenly ravenous soit is good to educate them about beingorganised and preparing ahead of time.

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Many young athletes are eager to increase therate of their growth and muscular developmentin pursuit of the physique of an adult. Whilegrowth and maturation are geneticallydetermined, high-energy eating plans canassist the young athlete to maximise theoutcomes 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 that containhigh amounts of caffeine and are not suitablefor young athletes. Athletes and coaches shouldbe aware that supplements do not provide ashort cut to success.

Ways to encourage good nutrition practices in childrenEncourage children to become involved inmenu planning for the family meals, and forspecial needs associated with their training andcompetition sessions.

Encourage positive messages that good eatingpractices, involving good choices of foods anddrinks, are part of the formula for sportingsuccess, and a healthy life.

Plan ahead to have nutrient-rich snacks tomeet energy needs over the day, and thespecial needs of fuelling up for sport orrecovering after the session. Some preparationis needed to have these choices on handthroughout the day, and before or after sport.

The female athlete

As well as the specific nutritional needs oftheir sport, female athletes face someadditional dietary needs and challenges totheir male counterparts:

l Having additional requirements for some nutrients (e.g. iron).

l Having lower energy requirements due to low body mass and muscle mass, and perhaps a lighter training load.

l Facing pressure to achieve lower levels of body fat than seems natural or healthy for their body.

l Greater risk of succumbing to stress related to body image and food.

Information related to good practice in theseareas is found in other sections of thisbooklet. However, it is worth noting here thatthere is enormous pressure on many femaleathletes to achieve an unrealistic body massand body fat level. This can compromise bothshort-term athletic performance and long-termhealth, with the real possibility of harm toreproductive and bone health. Any athlete withmenstrual irregularities should treat this as apossible warning sign, and seek professionaladvice. Female athletes, and indeed anyathlete who develops stress related to eatingand their physique, should seek expert help atan early stage.

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Most 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, someof which are listed below:

l Disruptions to the normal training routine and lifestyle while en route.

l Changes in climate and environment that create different nutritional needs.

l Jet lagl Changes to food availability, including

absence of important and familiar foods.l Reliance on hotels, restaurants and

takeaways instead of home cooking.l Exposure to new foods and eating cultures.l Temptations of an “all you can eat” dining

hall in an Athletes’ Village.l Risk of gastrointestinal illnesses due to

exposure to food and water with poor hygiene standards.

l Excitement and distraction of a new environment.

l Changes in digestion and/or pattern of bowel movements due to travel.

The keys to eating well while travelling areprovided below:

1. Planning ahead

Investigate food patterns and availability at yourdestination before you leave home. Competitionorganisers and athletes who have undertakenthis event on previous occasions may be ableto supply useful information on what to expect.This may help you to plan useful food suppliesto take on your travels that can replace missingand important items.

Contact the catering organisers at yourdestination to let them know of your specialdietary needs and your needs for meal timingand menus.

Make an eating plan for travel that incorporatesthe best of the available food supplies (e.g.airline catering, restaurants en route) as well asself-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 if yousuccumb to “boredom eating”. Be aware ofeating to real need.

When moving to a new time zone, adopt eatingpatterns that suit your destination as soon asthe trip starts. This will help to adapt your bodyclock.

Be aware of unseen fluid losses in airconditioned vehicles and pressurised planecabins. Have a drink plan that keeps you wellhydrated.

Eating while travelling

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 of water and other drinks or hot drinks. Bewary of ice added to drinks – it is often madefrom tap 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 an“authentic cultural experience”.

Stick to food that has been well-cooked, andavoid salads or unpeeled fruit that has been incontact with local water or soil.

4. Choose well from local cuisine andsupplement with non-perishable foodsupplies brought from home.

It is often a good idea to bring some snacksand favourite foods with you, especially if youare away from home for a long time and yourfavourites are not available at your destination.Remember, though, that many countriesprohibit the import of fresh foods: check aheadto see what is permitted so you can avoidhaving prohibited items confiscated at theairport. Do not take the risk of trying tosmuggle food – you may be refused entry.

Ideas for portable foods for the travelling athlete:

l Breakfast cereal l Powdered milkl Cereal bars and granola barsl Rice cakes, crackers, pretzelsl Spreads – honey, jam, peanut butterl Portion packs of canned fruitl Tinned or vacuum packed tuna, baked

beansl Powdered sports drinks, liquid meal

supplements, whey protein powderl Meal replacement bars and sports bars l Dried fruit and nuts

5. Use clever tactics in restaurants andwhen choosing takeaways

Stick to an eating plan based on what younormally eaten at home or your new nutritionalneeds, rather than being mesmerised by all thefood being offered.

Where possible, organise menus and mealtimes with restaurants ahead of time, especiallywhen dining with a large group. It is useful tobe able to arrive at the restaurant with the mealall ready to be served.

Where possible, consider the advantages ofbuffet style meal service. It is usually morecost-effective and offers more flexibility inallowing athletes to choose their individualneeds and likes.

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Be assertive in asking for foods to be preparedto your needs – for example, with low fatcooking methods, or with an addedcarbohydrate serving.

Avoid hanging around in restaurants or dininghalls for entertainment – it can often lead tounplanned 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.

Special tips for eating in an Athlete Dining Hallare provided in the next section.

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Imagine being able to eat in a self-serverestaurant that is open 24/7, has an almostunlimited menu from International cuisines,input from some of the best caterers and sportsnutrition experts in the world, and is free! Howcould you go wrong?

Unfortunately, although the Olympic VillageDining Hall provides a benchmark in cateringfor athletes and is a memorable experience formany Olympians, some of those memories maybe of lost opportunities and poor nutritionoutcomes rather than the opposite. Someathletes fail to achieve the potential of thedining experience and adopt poor nutritionpractices at a critical time in their sportingcareers. The fault is not the Dining Hall itself,but the failure of some athletes to recogniseand respond to the challenges of this neweating environment.

A sudden switch to communal cafeteria-styleeating creates the following issues that may benew to many athletes:

Great quantities and many different choicesof food. Many athletes are not used tounlimited access to so many wonderful foods.The temptations and opportunities to overeatcan be so overwhelming that they become themajor reason for weight gain.

Different and unusual foods. Although themenu includes cuisine from around the world,inevitably some athletes find themselveswithout access to their favourite foods orimportant menu items in their usualcompetition repertoire. Athletes may be

reluctant to try new things, finding themselvesunable to eat enough food or their specialnutritional requirements for competitionpreparation and recovery.

Food boredom. Many athletes live in theOlympic Village for 3-4 weeks. Although this is anexciting period, for the athlete who is trainingthrough to competition on the last days of theGames, the daily routine can lose its noveltysurprisingly quickly. Even though more choice isoffered than most people ever see in their normallives, the “sameness” of the environment and ofrepetitive eating habits can become boring. Itdoesn’t help if the athlete has developed thepractice of piling a “bit of everything” on theirplates at each meal so that there is no newtheme or change of menu. Strangely enough,some athletes who are surrounded by fantasticfood can become disinterested in eating and findmeal times a chore.

Lack of knowledge of the nutritionalcharacteristics of Dining Hall choices. Manyathletes don’t read English or have a hugeknowledge of food from outside their region.They may find it hard to understand what isbeing offered in the Dining Hall or how to makegood choices.

Lack of understanding of how to meetspecial food needs. Athletes with foodintolerances and allergies may not be confident offinding foods that meet their dietary restrictions.

Lack of supervision. For some athletes, theOlympic experience may be their first experienceaway from the guidance of their parents or

Eating in an Olympic Village Dining Hall

coach. It can be easy to become distracted.Some studies show that our food intakeincreases as we increase the size of the companysharing our mealtimes. Surrounded by the eatinghabits of other athletes, it may be difficult toconcentrate on your own nutritional goals.

Social eating. An athlete may not have muchtime or scope for leisure activities during thelast busy periods of competition preparation.Alternatively, their competition taper and timeaway from their usual world of training, study,medical appointments and across town travelmay suddenly create a lot of free time in theday. In any case, the Dining Hall becomes ameeting place and entertainment hub wheresocial eating or eating for enjoyment ratherthan real needs can sabotage the athlete’seating plan.

Many of these issues are faced by athletes wholive in University dorms or Specialised Trainingfacilities with cafeteria style eating. With someinsight into the new environment and foodchallenges, sound eating practices can beachieved.

Tips for eating well in communal cafeteriastyle Dining Halls:

Be clear about your eating goals and how thesechange during different phases of training andcompetition.

Be focussed on what you need to eat ratherthan what other athletes are eating.

On your first visits to the Dining Hall, learn thelayout including the different food stations andwhat they have to offer. Work on the philosophythat there is plenty of time to gradually workyour way around the menu options, rather thanhaving to try it all at once. This reduces boththe risk of overeating and of developing foodboredom. If the menu is available, you can planahead to make the most of what is on offer.Within a single meal, survey some optionsbefore making a considered choice.

Learn to understand the menu cards andnutritional labels offered. Many foods will havesymbols to let you know about the nutritionalcharacteristics of a food, or the presence orabsence of ingredients that you need to avoid.If you have doubts, seek advice from DiningHall staff, particularly the designated nutritionexperts or personnel in a Nutrition kiosk. It islikely that your special nutritional needs areavailable or can be arranged, if they are notimmediately obvious.

Find ways to keep yourself busy andentertained, especially during the taper beforecompetition when your energy needs arereduced, or when you are nervous and morevulnerable to temptation. Don’t go to the DiningHall unless it is time for a meal or snack, andmove to a new venue to hang out once youhave finished eating.

Allow yourself to have some treats or specialfoods, especially after your event is finished.However, keep perspective on the importanceof eating well for your event.

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Athletes train in every country of the world, andthey may face a number of differentenvironmental challenges. The athlete whotrains outdoors in winter in Russia or theAmerican mid-West is confronted with wind,snow and bitter cold, while the Saudi Arabianathlete who trains in mid-summer may facetemperatures of 50°C and high humidity. Inevery case, however, athletes learn to cope andit is often a matter of pride never to miss asession because of adverse weather conditions.

Athletes are sometimes required to compete inenvironments that are very different from thosethey are accustomed to at home, and this canpose special challenges. Every challenge,though, should be seen as an opportunity, andnutritional strategies can be adopted to helpathletes cope with environmental extremes.

London enjoys a temperate climate and thereare unlikely to be any extreme conditions at the2012 Games. Weather records show that thedaily temperature high in July and August islikely to be between 21 and 24 °C withmoderate humidity, falling to 10 - 12 °C at night.The temperature, however, may reach 35°C,which is enough to affect performance andrequires some attention from all competitors.Weather forecasts may be unreliable, and theweather can change very quickly, so you shouldbe prepared for all eventualities.

Special issues for exercise in hot climates

Most athletes enjoy opportunities for warm-weather training and competitions, but thesecan be challenging for all athletes, especiallyendurance 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.

Heat acclimation is achieved best byundertaking a series of exercise sessions in awarm environment. Undertaking 10-12workouts of about 60-100 minutes of modestexercise at intervals of not more than 2-3 dayswill achieve this.

Athletes not used to hot weather must beaware of the need to make some changesto their routine. Some suggestions areprovided below:

It may be necessary to modify the warm-up and reduce the amount of clothing worn to prevent over-heating and excess sweat loss before the event begins.

Extra fluids may be necessary. Since cool fluids will be more palatable, insulated drinks bottles are valuable.

There are many strategies involving ice vests,icy towels or cool baths that can help to coolathletes before, during or after sessions in hotenvironments. Some athletes also drink coldand icy fluids to contribute to these coolingstrategies. Since it requires moderate-largevolumes of fluid intake to make a differenceto body temperature, these and all strategiesshould be well practised before attempting ina competition setting.

Environmental challenges

The athlete should consider the side-effects or associated outcomes of all hot weather strategies. For example, an increased intake of sports drinks to meet additional fluid needs will also increase the athlete’s energy intake and affect energy balance.

Special issues for exercise at moderate altitudes

Athletes often undertake a period of specialisedtraining at moderate altitudes to use thephysiological adaptations it stimulates to assistwith their competition preparation. Listed beloware a number of adjustments that may help theathlete cope with altitude training:

Altitude camps are often a period of intensified training. The athlete may need to alter their energy intake to allow for the increased training load and the additional stresses of altitude.

As well as the additional muscle fuel costs of the increased training load, there is an increase in carbohydrate use during exerciseat altitude. The athlete should be more aggressive with refuelling strategies during aworkout, and over the day.

The cold and dry conditions at moderate altitudes cause an increase in water losses during breathing. This can lead to a substantial increase in fluid losses at moderate altitude compared with sea level. The athlete should take additional care to check fluid status over the day and during exercise sessions when they move to a higher altitude, since habitual drinking patterns may need to be adjusted to keep pace with these losses.

Since a move to a higher altitude may increase oxidative damage during exercise, athletes should ensure that their diet is rich in fruits and vegetables to provide essential antioxidants.

Good iron status is needed to maximise erythropoiesis (red blood cell production), which is an adaptive response to altitude exposure. Therefore athletes should consume adequate amounts of iron-rich foods. It may be worth checking iron status before undertaking altitude training.

Special issues for exercise in poor air quality

Athletes often have to train or compete in thepolluted environments of big cities, and arefaced with high levels of fumes, smog and dust.This can pose special challenges for athleteswith respiratory problems such as asthma, butall athletes and support staff may experienceminor respiratory problems in someenvironments. Air quality in London during theGames should be better than in many recentmajor Championship events.

It has been suggested that antioxidantsupplements may help reduce the severity ofsymptoms by neutralizing free radicalsproduced in response to airborne pollutants, butthe evidence for this is far from clear.Nonetheless, it seems sensible to ensure anadequate intake of fresh fruits and vegetablesto ensure good antioxidant defences.

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An infinite variety of different food combinationscan be chosen by athletes to meet theirnutritional goals. All the essential nutrients canbe obtained in adequate amounts from normalfoods. Variety is a key to meeting nutrientneeds, but many different foods can beinterchanged. Preferred sources of carbohydratemay be bread, rice, pasta, potato, couscous, orthe maize porridge favoured by many Kenyanathletes. Protein will be provided by manydifferent foods; the obvious protein-rich foodsare meat, fish, eggs and dairy produce, butbread, cereals, pasta, lentils and beans alsocontribute protein to the diet. The commonlyavailable fruits and vegetables will differ fromregion to region, although many staples orfavourites are exported around the globe.

Our eating habits are much more internationalthan they were, and athletes can enjoy foodsfrom different countries of the world. Ethnicrestaurants can be found in almost every majorcity of the world and London is especially well-served with examples of world cuisine. A visit toa restaurant that serves familiar foods may bea special “treat” for athletes and a chance toescape from the Village environment, but theseshould be checked beforehand. The advice oflocal athletes may be useful in identifyingsuitable options.

Considerations for Vegetarians Many 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 are bulky toconsume and may cause an inadvertentreduction in total energy intake. This mayincrease the risk of inadequate energyavailability and athletes should monitor bodymass and body composition to ensure energyneeds are being met.

Some athletes may use vegetarianism as ameans to restrict energy intake in order toachieve a desired physique: this seems to bemore common in female athletes but affectsmen too. All athletes should seek help from atrusted health professional if they feel out ofcontrol with calorie restriction and/or trying toachieve excessive leanness. Severe calorierestriction may compromise performance aswell as reproductive health and bone health.

Although most vegetarians meet or exceed theirprotein requirements, however, plant proteinquality and digestion is decreased and oftenrequires an intake of approximately 10% moreprotein than if consuming animal proteins.Therefore, protein recommendations forvegetarian athletes are approximately 1.3-1.8 g/kg/day from a variety of plant proteinsources. This fact may be of more concern forvegans - those who avoid all animal proteins,including fish, eggs and milk products.

Cultural and regional issues

It is still important to find a source of highquality protein to consume in the recovery fromkey workouts and events. Dairy or soy milkproducts may be suitable choices forvegetarians and vegans, respectively.

If there are no animal foods in the diet, then avitamin B12 supplement may be necessary.Some vegan food products, such as meatsubstitutes are B12 fortified – so it is importantif you adopt a vegan lifestyle to learn to readfood labels.

Avoiding red meat means that special attentionmust be paid to ensuring that the diet containsenough iron, especially during periods of rapidgrowth (e.g., adolescence), for women becauseof losses during menstruation, and before goingto altitude for training or competition. Ironintake from plant sources, should be combinedwith other 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 diet toensure an adequate calcium intake, but manycalcium-fortified foods are also available.Vegetarian athletes may also be at risk for lowintakes of fat (essential fatty acids areespecially important), riboflavin, vitamin D, andzinc which should be monitored andsupplemented in the diet if necessary.

Fasting for Ramadan

There may be special circumstances that causeathletes to change their normal training anddietary habits. Many Muslims avoid food andfluid intake during daylight hours during theholy 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 ofstrategies that allow their food and fluid intakefrom nightfall to dawn to maximise recoveryafter sessions and preparation for the next day.During phases of training, it may be possible tomove the time of workouts to better coincidewith their opportunities to consume foods anddrinks. Performance will not necessarily suffer ifthe athlete is well prepared, and it isrecommended that the athlete receivespecialised advice from training and nutritionexperts before deciding how to approach theirsporting commitments during Ramadan.

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Examples:Olympic weightlifting, powerlifting, throwingevents, 100-200 m sprints, body building.

Features and Challenges

l Periodised training involves resistance workouts, plus sport-specific workouts such as plyometrics, lifting, throwing.

l Goals are enhance power and strength, and in the case of body builders, to increase muscle hypertrophy (size).

l Main nutrition goals related to resistance training are:

– Fuelling training sessions – Recovering from training sessions– Maximising adaptations including an increase in muscle mass

l There is a culture of interest in high protein intakes

l There is a culture of interest in supplementsl In case of bodybuilders, there is a culture of

extreme diets to “cut up” for competitionl In case of lifters, there is a culture of

“making weight” for competition weight divisions

l Competitive events often involve multiple throws or lifts, or rounds (e.g. heats and finals)

Top 10 eating strategies for strengthsports:

l Consume a diet high in energy to support levels of high lean mass

l Consume adequate carbohydrate to fuel resistance training since this is glycogen-using

l Consume adequate but not excessive amounts of protein since these foods are expensive and may displace carbohydrate needs

l Consume a source of high quality protein (20-25 g) soon after resistance workouts

l Spread protein intake over the dayl Select low fat protein options to

avoid unnecessarily high intakes of saturated fat.

l Avoid extreme dieting behaviour prior to body building competition – rather, achieve loss of body fat by safe and longer-term methods

l Avoid extreme weight loss behaviour prior to weight lifting competition. Choosea suitable weight class and allow adequate time if weight loss is required toachieve this target. Small amounts of weight loss in the days before competition may be safely achieved

l For athletes participating in throwing and sprinting events, choose a pre-event mealthat keeps you comfortable throughout the competition. If there are rounds in your event or time between throws, makesure you have access to fluids and foods to keep you appropriately fuelled and hydrated.

l Seek the advice of a sports nutrition expert if you are unable to meet your goals easily or want specialised advice on supplement use.

Nutrition for strength sports

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Examples: Middle distance running, track cycling, rowing,canoeing/kayaking and swimming.

Features and Challenges

l Success is defined by the ability to produce very high power outputs for races ranging 1-10 minutes

l The continuum of fuel systems need to be well developed, requiring a highly periodised training program

l Nutrition goals change substantially with the different phases of training:

– General preparation: high training volume training, manipulation of body composition– Specific preparation: high intensity training, often with specialised periods such as altitude training– Taper/competition: lower volume/high intensity; race focus, avoidance of weight gain– Transition: light training, small weight gain usual

l Goals during training include achieving ideal physique, usually involving low body fat levels, and in some sports, muscularity. Competition physique may only be maintained for a short period. Some loss of physique during off-periods of the year but athletes should try to minimise this

l Performance of a race may be limited by build-up of acidity as a by product of sustained high-intensity work

l Competitive events often involve multiple rounds (heats, semis, finals etc)

Top 10 eating strategies for power sports:

l Vary energy intake between training phases according to the training load.

l Consume moderate-high levels of carbohydrate according to the fuel needs of the training phase

l Consume fluids and carbohydrate during prolonged training sessions to support hydration and fuel needs

l Consume a source of high quality protein (20-25 g) and carbohydrate soon after key workouts to promote refuelling and adaptation

l Achieve competition physique goals gradually with major effort during base phase and fine tuning just prior to racing season

l Consider the use of supplements carefully.Options that power athletes might use include buffers that are intracellular (β-alanine) and extracellular (bicarbonate)

l Choose a suitable pre-event meal that keeps you comfortable during your event.

l If there are heats and finals in your event, and especially, if you are competing in more than one event in a session, make sure you have access to fluids and foods to recover between races

l Look after special needs for specialised training phases such as altitude training. This may alter energy and fuel needs, fluid losses and iron requirements

l Seek the advice of a sports nutrition expert if you are unable to meet your goals easily or want specialised advice on supplement use

Nutrition for power sports

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Examples: Marathon, triathlon and road cycling.

Features and Challenges

l Success is defined by the ability to sustain performance over prolonged periods

l Nutrition goals change according to phase of training– General preparation: high training volumetraining, manipulation of body composition– Specific preparation: high intensity training, often with specialised periods such as altitude training– Taper/competition: lower volume/high intensity; race focus, avoidance of weight gain– Transition: light training, small weight gain usual

l Goals during training include achieving idealphysique, usually involving low body fat levels, and in some sports, muscularity. Competition physique may only be maintained for a short period. Some loss of physique during off-periods of the year but athletes should try to minimise this

l Athletes are often at risk of developing issues with eating and body image

l Fatigue or decline in performance during a race may be caused by dehydration, fuel depletion, gastrointestinal discomfort and other factors

l Opportunities for fluid and fuel intake duringa race vary according to the sport, but usually require the athlete to eat or drink “on the move”. Supplies may be provided atfeed zones or from team support crews or

may need to be carried by the athlete.l Competition phases differ according to

sports from marathon racing where athlete may undertake 1-2 major competitions per year to road cycling where professional cyclist may compete on 100 days of year

Top 10 Eating strategies

l Vary energy intake between training phases according to the training load. Maintain adequate energy availability

l Consume moderate-high levels of carbohydrate according to the fuel needs of the training phase

l Consume fluids and carbohydrate during prolonged training sessions to support hydration and fuel needs

l Consume nutrients after training sessions to target elements of recovery – this includes fluids and electrolytes for rehydration, carbohydrate for refuelling and a source of high quality protein (20-25 g) to promote muscle adaptation

l Set safe and achieve physique goals fortraining gradually, with major effort during base phase and fine tuning just prior to racing season

l Prepare for competition with carbohydrate fuelling techniques suited to the fuel needs of the event. For events lasting longer than 90 minutes, consider carbohydrate loading over the 2-3 days prior to the race.

Nutrition for endurance sports

l Choose a pre-race meal that promotes additional fuelling but leaves the gut feeling light and comfortable for the race

l Develop a plan of eating and drinking during the race to maintain adequate hydration and additional carbohydrate depending on the fuel needs of the event. Carbohydrate goals may range from small frequent “tastes” during brief events (45-75 min) to aggressive intakes of up to 80-90 g/h in ultra-endurance races (> 2.5 h). Practise theplan in training to perfect it.

l Consider the use of sports foods and supplements carefully: options include caffeine, sports gels/bars/drinks.

l Look after special needs for specialisedtraining phases such as altitude training. This may alter energy and fuel needs, fluid losses and iron requirements

l Seek the advice of a sports nutrition expert if you are unable to meet your goals easily or want specialised advice on supplement use

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Examples: figure skating, gymnastics, diving,combative sports, lightweight rowing.

Features and Challenges

l Success in the aesthetic sports may be defined at least partially by the athlete’s appearance and a subjective judgement of how it conforms to ideal in that sport

l Physical skills may be assisted by a small and light physique that makes it easy to move in a small space

l Athletes in some sports are classified in weight division to promote competition between people of similar size and strength. In these sports, there is a culture of “makingweight” for competition weight divisions

l Training loads vary according to the sport but and may range from high volume/intensity (lightweight rowing) to lengthy but moderate in energy expenditure (e.g. gymnastics)

l The emphasis on low body mass and low body fat levels creates an increased risk of issues with eating and body image

Top 10 Eating strategies

l Maintain adequate energy availability for your training and competition energy expenditure. Factor in needs for growth

l Consume moderate-high levels of carbohydrate according to the fuel needs of the training phase

l Choose weight and body fat goals that are achievable and support long-term health andperformance

l Choose nutrient dense foods, and a good spread of high quality protein over the day so that you maximise your ability to meet nutritional goals

l In weight category sports, choose a weight division that can be achieved safely and within minimal stress

l If you feel you are developing issues with food related stress, seek intervention at an early stage

l Prepare for competition by fine-tuning weight, without the need for extreme weight loss measures

l If you have made weight using techniques based on mild dehydration and reduction in food intake, use the period after the weigh into rehydrate and fuel up for the event.

l Consider the use of supplements carefully: there are no magic pills or potions that promote loss of body fat

l Seek the advice of a sports nutrition expert ifyou are unable to meet your goals easily or want specialised advice on managing your weight and physique goals

Nutrition for aesthetic and weight class sports

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Examples: football codes, basketball, field hockey, netball.

Features and Challenges

l Nutrition goals change according to phase of highly periodised yearly calendar– General preparation: high training volumetraining, manipulation of bodycomposition

– Pre-season preparation: Increase in skillsand tactical training; practice games

– Competition: may involve a large numberof games, with 2-7 days recovery

– Off-season: no scheduled traininglWork patterns involve high-intensity

intermittent exercise with brief recovery intervals: patterns vary between players and between matches

l Success is determined by overlay of skills onthese work patterns, requiring concentration and judgement

l A range of desirable physiques exists according to sport and to position within a team: may include need for bulk and muscularity or leanness and low body fat levels

l Competition may be in weekly fixture or in tournament format: both require recovery after match

l Fatigue or decline in performance during a match may be caused by dehydration, fuel depletion, gastrointestinal discomfort and other factors

l Opportunities to consume fluids and carbohydrate during a match vary according to the rules of the sport. There may be breaks between periods, substitutions or informal breaks in play that allow nutritional support

l In many team sports there is a culture of alcohol misuse after matches and during theoff season

Top 10 Eating strategies

l Periodise energy and carbohydrate intake according to the fuel needs of the training/competition phase

l Consume fluids and carbohydrate during prolonged training sessions to support hydration and fuel needs

l Consume nutrients after training sessions or matches to target elements of recovery – this includes fluids and electrolytes for rehydration, carbohydrate for refuelling and asource of high quality protein (20-25 g) to promote muscle adaptation

l Set safe and achieve physique goals for training gradually, with major effort during base phase and fine tuning prior to competition season. Avoid large loss of conditioning during the off-season

l Prepare for matches with carbohydrate intake suited to the fuel needs of the event. Midfield players and others with heavy workloads should consider more aggressive carbohydrate intake in the 1-2 days prior to the match.

l Choose a pre-match meal according to the time of day that promotes additional fuelling but leaves the gut feeling comfortable

Nutrition for team sports

l Develop a plan of eating and drinking duringthe match according to the available opportunities. Aim to maintain adequate hydration and additional carbohydrate depending on the fuel needs of the event. Carbohydrate goals may range from small frequent “tastes” during brief matches (45-75 min) to intakes of 30-60 g per hour for matches of 60-90 min. Practice the plan in training sessions and pre-season games to perfect it.

l Develop a sensible attitude to alcohol intakel Consider the use of sports foods and

supplements carefully: options include caffeine, sports gels/bars/drinks.

l Seek the advice of a sports nutrition expert ifyou are unable to meet your goals easily or want specialised advice on managing your weight and physique goals

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Scientific papers presented at the IOCConsensus Conference on Nutrition for Sportheld at the IOC offices in Lausanne in October 2010

1. Anne B. Loucks, Bente Kiens, Hattie H Wright. Energy availability in athletes. Journal of Sports Sciences, 2011, 29(S1), S7-S15

2. Louise Burke, John A Hawley, Stephen H Wong, Asker E Jeukendrup. Carbohydrates for training and competition. Journal of Sports Sciences, 2011, 29(S1), S17-S27

3. Stuart M Phillips, Luc JC van Loon. Dietary protein for athletes: from requirements to optimum adaptation. Journal of Sports Sciences, 2011, 29(S1), S29-S38

4. Susan M Shirreffs, Michael N Sawka. Fluid and electrolyte needs for training, competition and recovery. Journal of Sports Sciences, 2011, 29(S1), S39-S46

5. Scott Powers, W Bradley Nelson, Enette Larson-Meyer. Antioxidant and Vitamin D supplements for athletes: sense or nonsense? Journal of Sports Sciences, 2011, 29(S1), S47-S55

6. Ronald J Maughan, Paul L Greenhaff, Peter Hespel. Dietary supplements for athletes: emerging trends and recurring themes. Journal of Sports Sciences, 2011, 29(S1), S57-S66

7. Gary Slater, Stuart M Phillips. Strength sports: weightlifting, throwing events, body building, sprints. Journal of Sports Sciences, 2011, 29(S1), S67-S77

8. Trent Stellingwerff, Ronald J Maughan, Louise M Burke. Nutrition for power sports: middle-distance running, track cycling, rowing, canoeing/kayaking, and swimming. Journal of Sports Sciences, 2011, 29(S1), S79-S89

9. Asker E Jeukendrup. Endurance sports: marathon, triathlon, road cycling. Journal of Sports Sciences, 2011, 29(S1), S91-S99

10. Jorunn Sundgot-Borgen, Ina Garthe. Elite athletes in aesthetic and Olympic weight-class sports and the challenge of weight andbody composition. Journal of Sports Sciences, 2011, 29(S1), S101-S114

11. Francis Holway, Lawrence L Spriet. Practical strategies for team sports. Journal of Sports Sciences, 2011, 29(S1), S115-S125

12. Nanna L Meyer, Melinda Manore, Christine Helle. Winter sports. Journal of Sports Sciences, 2011, 29(S1), S127-S136

References

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Diet significantly influences athleticperformance. All athletes should adopt specificnutritional strategies before, during and aftertraining and competition to maximise theirmental and physical performance. Evidence-based guidelines on the amount, composition,and timing of food intake have been defined tohelp athletes perform and train more effectively,with less risk of illness and injury.

Athletes will benefit from the guidance ofqualified sports nutrition professionals who canadvise on their individual energy, nutrient andfluid needs and help develop sport-specificnutritional strategies for training, competitionand recovery. Energy demands depend on theperiodised training load and competitionprogram, and will vary from day to day andacross the season. A diet that providesadequate energy from a wide range ofcommonly available foods can meet thecarbohydrate, protein, fat and micronutrientrequirements of training and competition. Anappropriate diet will help athletes reach anoptimum body size and body composition toachieve greater success in their sport.

Careful selection of nutrient-rich foods to reducethe risk of developing nutrient deficiencies thatimpair both health and performance isespecially important when energy intake isrestricted to reduce body and/or fat mass.During high-intensity training, particularly of longduration, athletes should aim to achievecarbohydrate intakes that meet the needs oftheir training programs and also adequatelyreplace carbohydrate stores during recovery

between training sessions and competitions.Dietary protein should be consumed in dailyamounts greater than those recommended forthe general population, but a varied diet thatmeets energy needs will generally provideprotein in excess of requirements.

Foods or snacks that contain high-qualityproteins should be consumed regularlythroughout the day as part of the day’s totalprotein intake, and in particular soon afterexercise, in quantities sufficient to maximise thesynthesis of proteins, to aid in long-termmaintenance or gain of muscle and bone and inthe repair of damaged tissues. Ingestion offoods or drinks providing 15-25 g of suchprotein after each training session will maximisethe synthesis of proteins that underpins thesegoals. For events lasting an hour or more, theathlete should aim to begin competition withbody carbohydrate stores sufficient to meet theirneeds by consuming carbohydrate-rich foods inthe hours and days beforehand.

Ingestion of even small amounts of carbohydrateduring exercise can enhance cognitive andphysical performance in competition lasting onehour. As the duration of the event increases, sodoes the amount of carbohydrate needed tooptimise performance. To achieve the relativelyhigh rates of intake (up to 90 g/h) needed tooptimise performance in events lasting morethan about 3 hours, athletes should practiseconsuming carbohydrate during training todevelop an individual strategy, and should makeuse of sports foods and drinks containingcarbohydrate combinations that will maximise

IOC Consensus Statementon Sports Nutrition 2010at

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absorption from the gut and minimisegastrointestinal disturbances. Dehydration, ifsufficiently severe, can impair performance inmost events, particularly in warm and high-altitude environments. Athletes should be wellhydrated before exercise and drink sufficientfluid during exercise to limit dehydration to lessthan about 2% of body mass. Chilled fluids maybenefit performance in hot conditions.

Athletes should not drink so much that they gainweight during exercise. Sodium should beincluded when sweat losses are high, especiallywhen exercise lasts more than about 2 hours.During recovery from exercise, rehydrationshould include replacement of both water andsalts lost in sweat. When athletes must competein several events in a short time-period,strategies to enhance recovery of fluid and fuelare important. Low energy availability should beavoided, as it can impair performance andadaptation to training and may be harmful tobrain, reproductive, metabolic and immunefunction, and to bone health.

Dieting in young athletes should bediscouraged. Robust immunity and reduced riskof infection can be achieved by consuming avaried diet adequate in energy andmicronutrients, ensuring adequate sleep andlimiting other life stress. Athletes should beparticularly aware of their needs for calcium,iron and Vitamin D, but the use of largeamounts of some micronutrients may beharmful. Athletes at risk of disordered eatingpatterns and reproductive disorders should bepromptly referred to a qualified health

professional for evaluation and treatment. Theuse of supplements does not compensate forpoor food choices and an inadequate diet, butsupplements that provide essential nutrientsmay be a short-term option when food intake orfood choices are restricted due to travel or otherfactors. Vitamin D may be needed insupplemental form when sun exposure isinadequate.

Of the many different dietary ergogenic aidsavailable to athletes, a very small number mayenhance performance for some athletes whenused in accordance with current evidence underthe guidance of a well-informed professional.Athletes contemplating the use of supplementsand sports foods should consider their efficacy,their cost, the risk to health and performance,and the potential for a positive doping test.Supplement use in young athletes should bediscouraged, and the focus should be onconsuming a nutrient-rich, well-chosen diet toallow for growth while maintaining a healthybody composition. To enjoy all the benefits ofsport, athletes, whether they compete at theelite level or exercise on a recreational basis,should adopt specific nutrition strategies thatcan optimise mental and physical performanceand support good health.

Lausanne, 27 October 2010

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