Fuel the hours you have not reached yet
Nutrition & Hydration
What to eat, when to eat, how to reduce GI distress, and the science of fueling through days of continuous movement.
Nutrition for multiday running is not a single perfect product. It is an individualized, practiced system of food and drink that can adapt when effort, sleep loss, heat, appetite, and tolerance change.
These guides give hourly fueling targets, fluid and sodium ranges, and fallback plans for 24-hour races, backyard ultras, and longer efforts where the stomach becomes part of the race strategy.
Backyard Ultra Nutrition: What to Eat Between Loops
A per-yard backyard ultra fueling plan: 50 g carbs per yard early, a 30 g floor late, protein and caffeine doses, and how to use 15, then 6, minutes at base.
What to Focus On
24-Hour Race Fueling
Plan a tested fueling range, thirst-led fluid choices, optional caffeine, and fallback foods for the full day and night.
Backyard Ultra Nutrition
Test optional food, thirst-led fluid, and rest choices that fit the time remaining before each hourly start.
Products and Practical Setup
Build a tested mix of drink fuel, gels, familiar food, warm options, and any optional electrolyte or caffeine products.
Hydration and Sodium
Use thirst as the starting signal, avoid forced fluid, and remember that sodium intake does not make overdrinking safe.
All Guides
What to Eat During a 24-Hour Race: Hour-by-Hour Plan
A 24-hour race burns roughly 8,000–13,000 kcal. Our hour-by-hour plan: 50 g carbs per hour early, a 30 g floor late, fluid, sodium and caffeine doses.
Hydration and Sodium for Ultramarathons
Drink to thirst, about 450–750 mL per hour (ISSN), with 300–600 mg sodium per hour, a sweat-rate test, and why weight gain means you are overdrinking.
Gut Training for Ultrarunners: A Safe Practice Guide
An optional six-week gut-practice sequence for ultrarunners, with individualized fueling, hydration and caffeine guidance plus medical red flags.
Common Questions
How should you plan energy intake?
Plan around 50 g of carbohydrate and 200–300 kcal an hour. Treat 30 g and 200 kcal an hour as the floor, move toward 60–75 g only with a trained gut, and treat 90 g as the ceiling. The 24-hour and backyard guides turn this into hour-by-hour and yard-by-yard plans.
Should you rely on gels for a full day?
Gels can be part of a full-day plan, but flavor and texture tolerance vary. Test whether you benefit from alternatives such as drink mix, familiar food, savory options, warm liquids, or bland fallback foods.
When should caffeine start?
Save it for the later stages, usually from the first evening. The ultramarathon position stand suggests repeat doses of 1–2 mg per kg (70–140 mg for a 70 kg runner) and about 50 mg an hour overnight. Test the exact product in training and count every source, including cola.