5IOC Consensus Conference on Nutrition and Sports Performance "The amount, composition and timing of food intake can profoundly affect sports performance"IOC Consensus Conference on Nutrition and Sports PerformanceDiet significantly influences athletic performance. An adequate diet in terns of quantity and quality, before during and after training will maximise performance –which of course is our ultimate goal.
6The benefits of eating well include: Around the world, athletes and coaches recognise that nutrition plays a major role in achieving success in sport.The benefits of eating well include:Optimal gains from the training programEnhanced recovery between workouts and eventsAchievement and maintenance of an ideal body weight and physiqueA reduced risk of injury and illnessConfidence in being well-prepared to face competitionConsistency in achieving high level competition performancesFor all individuals who exercise or participate in sports, optimal nutrition can: improve performance, decrease recovery time from strenous events, prevent exercise related injuries due to tiredness, fatigue caused by quite simply running out of fuel, it will provide the fuel required during high intensity training for competing and will also control weight (which is usually more important in sports where you have to make weight). So lets look at what the optimum diet for sport is.
7UK Dietary intake Values refer to % of energy intake At the minute the average UK diet consists of 40% of total energy from carbohydrate, 40% from fat and 20% from protein, now this isnt even in line with the recommended government intake for normal individuals who will not be taking part in sport. So if we move on to look at what the recommended dietary intake is for sport …Values refer to % of energy intake
8Healthy dietWe see that the recommended intake for a healthy diet is 50% of total energy coming from carbohydrate, 30% from fat and 20% from protein. Now this intake might be suitable for the average Joe Bloggs walking down the street, however due to the demands placed on you when training and competing for sailing, this will not supply you with all of the energy and nutrients which you require. So we now need to step it up a gear and look at the recommended diet for sport.
9Optimum diet for sportSo the recommended healthy diet for sport is 60% of total energy coming from carbohydrate, 25% from fats (preferably healthy fats from plant sources as opposed to animal sources and 15% of total energy coming from protein. Now so far ive showed you this information in terms of % and unless you are a nutritionist this is not really going to make much sense when you are planning your meals for competition – so what I would like to do now is look at how you can achieve this healthy diet for sport during training and competition periods. A high carbohydrate diet can be bulky, so many athletes prefer to eat frequent meals and snacks to ensure that they consume enough energy.Food high in carbohydrate include:•Bread, rice, potatoes, pasta and other starchy foods.• Foods containing sugars such as fruit, jams, table sugar, puddings and confectionary are high in sugar (carbohydrate) and can be useful before an event.• Drinks such as fruit juice, carbonated drinks, squash and some sports drinks
10Why is an athletes diet different? EnergyIncreased energy demands from increased activityMaintenance of energy balance must be assessedWeight lossIncreased fluid intake
11Food for EnergyEnergy from the diet is stored as body fat or glycogen (carbohydrate in muscles and liver) and can be broken down to provide energy.Glycogen is the main source of energy during short bursts of activity and at the start of exercise.There is only a small store of glycogen in the body, and as exercise continues the store becomes depleted and the body starts to use some fat to provide energy. Most people have quite a large store of body fat.People who are fitter use up their store of glycogen more slowly, and tend to use their stores of body fat for fuel more readily.Eating a diet high in carbohydrate ensures that muscle and liver glycogen stores are maintained.If most of the glycogen in muscles and liver is used, such as after prolonged exercise, blood sugar levels can drop below normal and this can cause fatigue, nausea and dizziness.Carbohydrate rich foods are also important for replenishing glycogen stores after an event.
12Carbohydrates to fuel your training! Preferred fuel for aerobic and anaerobic energy systemsDelay fatigue in exercise lasting longer than 60 minutesEssential role in recoveryStrength and power athletes require approximately 5-7gms/Kg body weight for hard trainingEndurance athletes 7-10gms/Kg body weight12
13Carbohydrate Athletic performance limited by CHO availability High intensity + long duration sportsHigh CHO diets maximize glycogen stores + performanceRequirements sugar/starch, liquid/solid dependent on:Timing + type of physical activityAthletes in endurance events, such as long distance running, often eat large amounts of carbohydrate for several days before the competition (up to 70% of energy).This is called carbohydrate loading.It increases the body’s store of glycogen.Trained athletes have the ability to have greater glycogen stores as a side effect of training.
15Preparing for Sport gut blood liver glucose 100 g muscle glycogen
16Typical training day for an elite boxer Running/Cardio30-60minsREST/MEALSparring/Boxing3min rounds 30sec rest roundsWeight Training2 muscle groups pre session 4 sets of 20 reps per muscle group 180 reps per gym session
17Does it help build muscles and aid recovery? What about protein?The body uses protein from the diet for growth and repair of tissues – which is of great importance if you suffer from strain/injury during training.Does it help build muscles and aid recovery?Protein can help build muscle in resistance sports such as weight lifting but be warned excess protein is turned into adipose tissue (fat!)Athletes need slightly more protein in their diets than the rest of the population in order to repair and build muscle.Because athletes generally eat more (to meet their energy requirements) they are likely to meet their protein needs by choosing a balanced diet. They do not need to consume food high in protein.Athletes do not need large amounts of meat or to take supplements.Eating more protein than the body needs does not increase the amount of muscle in the body.
18Protein Large Organic compounds made of amino acids Complex structure difficult to break downThe body rarely uses protein as a source of fuelProtein often used as a food supplement to aid muscle growthProteins are an extremely important macromoleculeIf an athlete’s diet contains too little energy from carbohydrate, protein from the diet will be used to provide energy.This is not desirable as less protein will be available for forming and repairing muscle tissue – the main function of protein.
21Fat Can be liquid or solid depending on structure Different kinds of fats.SaturatedUnsaturatedFatty acids (Omega 3,6,9)NOT ALL FATS ARE BAD – all about balance
22Another approach to having “extra” glycogen – train your body to use less The alternative to maximizing the availability of CHO is to conserve CHO by maximizing the capacity to oxidize fat. The essential theory underlying this strategy is the reciprocal relationship between FAT and CHO in terms of providing energy for exercise.GlycogenTriglycerideGlucoseFree Fatty AcidPyruvateAcetyl-CoAFatty Acyl CoATCA (Krebs) cycle
23Exercise and Supplements Diet is important for all athletesDue to lifestyle and training programmes and energy demands its not always possible to gain requirement from foodsMany athletes use food supplements
24Types of Supplements Carbohydrate shake, and bars Protein shakes, and barsCaffeine supplementsEnergy drinksVitamin supplementsIron + calcium supplements
25Vitamin supplementsIf you have a healthy balanced diet then you should not need to use vitamin supplements. However, if you do take one pick a multi-vitamin/mineral supplement providing no more than 100% RDA (recommended daily allowance)
26BUT … at what point does the use of supplements become cheating ???
27Athletic substance abuse “The International Olympic Committee (IOC) published its first list of banned doping classes in 1967, in which it listed narcotic analgesics, sympathomimetic amines, psychomotor stimulants, and miscellaneous central nervous system stimulants. Since that time the list has evolved and grown, with the incorporation of anabolic steroids in 1974, blockers and diuretics in 1985, and peptide hormones in 1989”.
28Responsibility of athletes It is the responsibility of the athlete to understand their rights and responsibilities and to be aware of what they are putting in their body, despite whether there was an intention to cheat or notAthletes should seek advice if they have any questions or doubts about their responsibility, medication or treatment.It's what's inside that countsInternational IOC-study (2001) showed Cross-contamination of nutritional supplements14.8% of the nutritional supplements contained prohormones not declared on the label demonstrating that labelling of preparations does not reflect their actual content
29Caffeine’s Ergogenic Effect Increased mental alertness/concentration central nervous system stimulantElevated mood/ decreased fatigueEnhanced catecholamine releaseImproved muscular strengthEffect Depends on:Individual caffeine statusIndividual variabilityCaffeine dosage and administrationIllegal (>12ug/ml)approx cups of strong coffee or 4 vivarin for a 150 pound person consumed 2-3 hours before performance
30Alcohol Alcohol effects all cells in the body. Alcohol (ethyl alcohol, ethanol) is a drug, it can also be classified as an energy source as it provides energy, about 7 kcal per gram.“uneconomical” - more oxygen needed to metabolize a gram of alcohol than a gram of carbohydrates or fatThe effects of alcohol are dependant on the blood alcohol concentration.
31AlcoholAlcohol may influence both psychological and physiological processes related to physical performance.Psychologically, alcohol may benefit performance by increasing self-confidence, decreasing sensitivity to pain, or removing psychological barriers to performance.However, the most prevalent use of alcohol in sports competition is related to its ability to reduce excess anxiety.negative effects on performance;increased heart rate and oxygen consumptionincreased blood pressure and blood lactateincreased reaction timeimpaired hand-eye coordination and visual perceptioncurrently not banned by IOC except for shooting competitions
32Anabolic SteroidsTestosterone (must be injected or it will be destroyed by digestive enzymes)Anabolic Androgenic Steroids (AAS)synthetic drugs designed to mimic the effects of testosterone; taken orally or injectedHuman Growth Hormone (anabolic)used like steroids to increase muscle massBeta Adrenergic Agents (Clenbuterol)
33Athlete substance abuse IOC list of banned substancesAmphetaminesReduce fatigue, improve alertness, improve reaction time, increase aggression and competitiveness. May be used outside of competition to improve training. Contained within recreational drugs.Release neurotransmitters such as noradrenalin, dopamine, and serotoninFound in over the counter medicines such as cold remedies and decongestants.
34Athlete substance abuse β agonistsPotent bronchodilators and may, therefore, improve performance in aerobic exerciseCommonly found in asthma inhalersAllowed for medical reasons6% of athletes at the 2000 Sydney Olympics declared the use of β agonists.
35Athlete substance abuse Anabolic androgenic steroidsAnabolic androgenic steroids (AAS) are used to improve strength by increasing lean body mass, decreasing body fat, prolonging training by enhancing recovery time, and increasing aggressiveness and energy cardiovascular, cosmetic, hepatic, infections, reproductive, and psychiatric.
36Other inhibiting factors SleepSleep is important for the body and the brain, helps recovery and healing from the stress of exercise.StressEmotional stress effects performance be reducing commitment and concentration levels particularly important in sports with high skill factors.InjuriesInjuries reduce training intensities and effect performance. Injuries can be a sign of over training or incorrect diet.