Hours zero to four: the fast carb window

Early on, your gut is cooperative and the job is simple: steady simple carbohydrates, little and often, from the gun rather than from the first dip. What works: energy gels and chews for precision, sports drink doing double duty with fluids, bananas, dates, jelly sweets, white bread with jam or honey, rice cakes, and fruit purée pouches. The classic first-timer error is building the entire plan here, all gels, all sugar, because it works beautifully in hour two and then mutinies in hour seven. If gels already turn your stomach even in training, our energy gel alternatives guide is the fix; either way, cap the sugar-only phase deliberately and move to real food earlier than feels necessary.

Hours four to ten: the real food shift

This is where ultras are actually fuelled, and where the sport's strange food culture comes from. As gut fatigue and palate fatigue arrive, solid, savoury, familiar food starts outperforming sports products: salted boiled potatoes, sticky rice balls, plain wraps with peanut butter or cheese, small sandwiches, oat bars and flapjacks, pretzels and salted crisps for the sodium your sweat has been spending, mild cheese, malt loaf, and the aid station's quiet hero, plain salted rice. The eating technique matters as much as the menu: solids go down on the walking climbs, in small bites, chewed properly, never on the runnable descents. Our ultra high carb solid foods guide ranks this entire category, and it's the deep dive this stage deserves. This is also the phase Phoenix Bars were built for: up to 557 calories and 66 grams of carbohydrate in one soft 120 gram bar that stays eatable when cold hands and a tired jaw have given up on anything chewy, which is exactly why they ride in vests at MDS and UK hundreds alike.

Hour ten and beyond: soft, salty, drinkable

Late in a long race, the rules change again. Sweetness becomes repulsive, chewing becomes work, and the food that rescues races barely counts as food: salty noodle soup, plain broth, tomato soup, rice pudding, custard pots, mashed potato, flat cola, warm sweet tea, and milky drinks where a crew can provide them. The principle is that liquid and semi-liquid calories slide past a gut that solid food can no longer negotiate with, and the salt is doing as much work as the carbohydrate. Two palate tricks the veterans use: brushing your teeth or chewing mint gum at a night checkpoint resets a wrecked palate, and alternating salty with sweet delays the point where both fail.

When everything stops working

It happens, and the answer is never to stop eating, it's to shrink the units: one crisp, one sip of coke, a fingernail of bar, every few minutes, walking while you do it, until the system reboots. Nausea deep in an ultra is usually a symptom of being behind on fuel, fluid or sodium, not a signal to stop taking them on. Fix the smallest deficit you can act on and the appetite usually follows within half an hour.

Foods that fail

High-fibre anything early, heavy fat in the first half, dry proteins like jerky and chicken that demand saliva you no longer have, spicy food unless deeply trained, fizzy drinks before they've gone flat, and above all, anything you've never eaten on a training run. The race is the exam, not the experiment.

The carry list versus the aid station list

Plan them separately. Your vest carries precision and insurance: your hourly carbs in trained formats, one dense solid item, and your sealed emergency food, which most races mandate and which one bar covers in a single 120 gram item, as covered in the ultra marathon kit list. Aid stations provide variety, hot options and morale, and the discipline there is take-away rather than picnic: grab what works, load a pocket, eat on the move.

Frequently asked questions

How many carbs per hour should I eat in an ultra? 60 to 90 grams per hour is the standard working range, with trained competitive runners pushing toward 120. Under-fuelling is the most common self-inflicted DNF in the sport.

Are gels enough for an ultra marathon? For most people, no. Gels excel early, but gut and palate fatigue turn a gels-only plan into a liability somewhere in the middle hours, which is why experienced runners transition to real, solid, savoury food and finish on soft and liquid calories.

What should I eat when I feel sick during an ultra? Shrink the units rather than stopping: tiny sips of flat cola or broth, single crisps, fragments of something bland, taken walking. Nausea usually signals a fuel, fluid or sodium deficit that eating your way through, gently, resolves.

What do ultra runners eat at aid stations? The staples are salted potatoes, crisps, sandwiches, sweets, fruit, coke and, at longer races, soup and noodles. Treat them as a supplement to a carried plan, not the plan itself.

What foods should I avoid in an ultra? Anything untested in training, high fibre and heavy fat early on, dry chewy proteins, and full-strength fizz. Familiarity beats optimisation every single time.

Written by James Frost, founder of Flaming Phoenix. We fuel ultra runners from UK trails to the Marathon des Sables, and this timeline is theirs. Last updated July 2026.