Carbohydrates are crucial for marathon runners, stored as glycogen in muscles and liver. Carb-loading increases glycogen stores, providing energy during races. Runners should aim for three carb-rich meals the day before a race.

On the final carb-loading day, choose low-fibre foods to avoid gastrointestinal issues. A 70-kg runner needs 630-840 grams of carbs, equivalent to 17 servings of spaghetti. Start carb-loading four to five days before the race. Read more racing coverage.

Grilled chicken, salmon, and tofu are good protein sources for pre-race meals. Pair them with carb-rich foods like white rice, pasta, or bread. Vegetables like potatoes, carrots, and corn also contribute to carbohydrate intake. Related: London Marathon 2027 Elite Races Decided by Rock, Paper, Scissors.

This original Runner World brief is based on reporting from Canadian Running. Visit the source for its complete reporting, context and any later corrections.