Elite sport is fuelled as precisely as it is trained. What athletes eat in the days before competition, during the event itself and in the recovery window afterwards can decide medals. Sports nutrition has evolved from folk wisdom into a science of grams, timing and individual testing. This guide explains what athletes eat, when, and why.

What should athletes eat before competition?

Pre-competition nutrition has two phases. In the days before, endurance athletes carb-load: increasing carbohydrate intake to 8 to 12 grams per kilogram of body weight while tapering training, maximising the glycogen stored in muscles and liver. The pre-event meal, eaten three to four hours before, should be high in carbohydrates, moderate in protein, low in fat and fibre, and familiar: oatmeal with banana, rice with lean chicken, or pasta with light sauce are classics. In the final hour, small carbohydrate snacks and fluids top up energy without upsetting the stomach. The golden rule is never experiment on competition day: every meal should have been rehearsed in training. Hydration begins the day before, with pale-yellow urine the simple indicator of readiness.

How do athletes fuel during competition?

For events lasting over an hour, fuelling during competition is essential. The body can absorb roughly 60 to 90 grams of carbohydrate per hour, delivered through sports drinks, energy gels, chews or real food like bananas and rice cakes in ultra-endurance events. Elite marathoners now use advanced carbohydrate mixes to push intake toward 90 grams hourly. Electrolytes, particularly sodium, replace what sweat removes; cramp-prone athletes pay special attention. In team sports, half-time brings gels and drinks; in tennis, players eat bananas and energy bars at changeovers. Even in shorter events, mouth-rinsing with carbohydrate drinks can trick the brain into permitting harder efforts. Fuelling strategy is now as rehearsed as any tactical plan.

What should athletes eat after competition?

The recovery window begins immediately. Within 30 to 60 minutes, athletes target carbohydrates to replenish glycogen, around 1 gram per kilogram of body weight, plus 20 to 40 grams of protein to repair muscle damage: chocolate milk, recovery shakes, or a proper meal all work. Rehydration means replacing 150 per cent of fluid lost, judged by pre- and post-exercise weigh-ins, with sodium to retain the fluid. In the following 24 hours, normal balanced eating resumes with an emphasis on total calories, because under-fuelling is the commonest nutritional error in heavy training. Sleep, the ultimate recovery tool, is supported by evening nutrition choices: adequate calories, limited caffeine and familiar foods.

How do nutritional needs differ by sport?

One diet does not fit all athletes. Endurance athletes prioritise carbohydrates, sometimes exceeding 10 grams per kilogram daily in heavy training. Strength and power athletes emphasise protein, around 1.6 to 2.2 grams per kilogram, spread across the day to maximise muscle synthesis. Weight-category athletes in wrestling, boxing and weightlifting manage the delicate art of making weight: gradual cuts through diet, with dangerous dehydration practices now discouraged and regulated. Aesthetic and endurance sports carry higher risks of under-fuelling, and the condition of Relative Energy Deficiency in Sport is now screened for across elite programmes. Team-sport athletes periodise nutrition around fixtures, eating more on match days and less on rest days.

What about supplements?

Supplements are the most misunderstood area of sports nutrition. A handful have strong evidence: creatine for strength and power, caffeine for endurance and alertness, beta-alanine for high-intensity efforts, and vitamin D and iron for deficient athletes. Protein powders are convenient but not magical; food works equally well. Everything else ranges from unproven to risky. Contamination is the great danger: supplements have caused positive doping tests through undeclared prohibited substances, so elite athletes use only batch-tested products certified by programmes like Informed Sport. The professional consensus is food first, supplements only to fill specific, tested gaps.

How is nutrition personalised?

Modern elite nutrition is individual. Sweat testing measures each athlete’s sodium losses; metabolic testing determines carbohydrate needs; gut training teaches the stomach to tolerate race-day fuelling; blood monitoring catches iron and vitamin D deficiencies. Cultural and personal factors matter: vegetarian athletes plan protein carefully, and religious fasting periods like Ramadan require adjusted training and fuelling schedules. Technology, from continuous glucose monitors to nutrition apps, adds data, but the best practitioners blend science with the athlete’s preferences. The goal is a fuelling plan the athlete trusts completely, because confidence in the plan is itself performance-enhancing.

FAQs

What is carb-loading? Increasing carbohydrate intake for several days before endurance events to maximise muscle glycogen stores, the body’s premium fuel.

How much protein do athletes need? Around 1.6 to 2.2 grams per kilogram of body weight daily for strength athletes, slightly less for endurance athletes.

Are energy gels safe? Yes, when used as directed with water; they are simply concentrated carbohydrates, but should always be tested in training first.

Before, during, after: sports nutrition is timing as much as food. Get the timing right, personalise the plan, and the dinner plate becomes part of the training programme.

Source: International Olympic Committee nutrition consensus