Running Gels and Mid-Run Fueling: A Practical Guide
Energy gels, chews, and drinks fuel long runs and races. Learn when to start fueling, how much carbohydrate to take per hour, and how to avoid stomach trouble.
April 24, 2026 · 2 min read
For runs and races lasting beyond about 60–90 minutes, mid-run fueling with carbohydrate — via gels, chews, or sports drinks — helps maintain energy and stave off the wall. A typical target is 30–60 grams of carbohydrate per hour, taken early and consistently. The cardinal rule: practice your fueling in training so your gut tolerates it on race day.
When to start fueling
Your body stores enough glycogen for roughly 90 minutes to two hours of hard running. Once you exceed that, fueling becomes important. But don't wait until you feel empty — start taking carbohydrate early, within the first 30–45 minutes of a long effort, so you stay ahead of depletion.
How much carbohydrate per hour
- Up to ~90 minutes: usually no fueling needed.
- Longer runs and half marathons: about 30–60g of carbs per hour.
- Marathons and ultras: 60g or more per hour for well-trained guts.
- Very long events: a mix of carb sources can improve absorption and tolerance.
Gels, chews, drinks, or real food
Gels are concentrated and convenient but should be taken with water. Chews are easy to portion. Sports drinks supply carbs and fluid together. On ultras, many runners prefer real food. There's no single best option — choose what your stomach tolerates and what suits the event's length and aid stations.
Train your gut
Your digestive system adapts to fueling on the move, just like your muscles adapt to running. Practice taking gels at race pace during long runs so race-day fueling is routine, not a gamble.
Avoiding stomach trouble
GI distress is common when runners take too much, too concentrated, or untested fuel. Take gels with water, avoid combining them with high-fiber or high-fat foods, and rehearse your exact plan in training. If one product upsets your stomach, try another — tolerance is individual.
Frequently asked questions
When should I take a gel during a run?
Start fueling early on long efforts — within the first 30–45 minutes — and continue at regular intervals, roughly every 30–45 minutes, rather than waiting until you feel depleted. Take gels with water.
How many carbs should I consume per hour while running?
About 30–60 grams of carbohydrate per hour for most long runs and races, with well-trained marathoners and ultrarunners sometimes taking 60g or more. Build up your tolerance gradually in training.
Why do energy gels upset my stomach?
Often because they're too concentrated without enough water, taken in too large a dose, or untested. Take gels with water, start with smaller amounts, and practice in training. If problems persist, try a different product.
Put it into practice
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