Race-Day Nutrition
What to eat before and during a race, by distance — and why race day is the wrong time to experiment.
The single most important rule of race nutrition: never try anything new on race day. Whatever you eat before and during the race should be something you've already tested on a long training run, because gut tolerance for food and gels under race-pace stress is highly individual.
For races under about 90 minutes (5K, 10K, most half marathons for faster runners), a light, carb-focused meal 2-3 hours before is usually enough — mid-race fueling is optional. For marathons and slower half marathons, plan on 30-60g of carbohydrate per hour once you're past the first 45 minutes, via gels, chews, or sports drink.
Hydration needs vary enormously by sweat rate, temperature, and pace — there's no single number that applies to everyone. A reasonable starting point is drinking to thirst rather than forcing a fixed volume, and adding electrolytes for anything over about 90 minutes or in hot conditions.
Carb-loading — shifting toward more carbohydrate for 1-2 days before a marathon — helps top off glycogen stores, but it means changing the ratio of what you eat, not simply eating more overall. Overeating in the name of carb-loading just leaves you sluggish on race morning.
This is educational content, not medical advice — talk to a doctor about anything specific to your health or an existing injury.