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 focus on practical fueling targets 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
Build a tested backyard-ultra fueling routine with flexible food choices, safer hydration, caffeine guardrails, gut practice, and clear medical red flags.
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 — Nutrition Strategy Guide
An individualized 24-hour ultramarathon nutrition guide covering food choices, GI symptoms, hydration safety, energy ranges, and caffeine planning.
Hydration and Sodium for Ultramarathons
A cautious, practical guide to fluid, sodium, thirst, sweat rate, and hyponatremia risk for long ultramarathons and multiday races.
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?
There is no universal target. Research offers a broad planning range, but your practiced intake should reflect body size, effort, duration, conditions, and gut tolerance; do not force a number through worsening nausea.
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?
There is no universal clock time. If you use caffeine, test the exact product and amount in training, count every source, and avoid using it to mask unsafe sleepiness or medical warning signs.