Build competition nutrition around the athlete's usual diet, the expected event duration and the real opportunities to eat or drink. World Athletics consensus supports a food first foundation, with strategies before, during and between events matched to the competition. AIS guidance treats sports drinks as one convenient way to combine carbohydrate, fluid and electrolytes, not an automatic requirement.
Write down the final substantial meal, optional familiar snack, caffeine decision, available aid points, any carried product the rules allow, approximate fluid approach and the first chance to eat after the finish. Test the sequence in a representative session. If the athlete has diabetes, gastrointestinal disease, kidney or heart disease, takes relevant medication, is pregnant, has a history of disordered eating or needs a clinical hydration plan, use qualified individual advice.