Runner Nutrition: What to Eat Before, During and After (10K to Marathon)

TL;DR — Before: a carb-rich, easy-to-digest meal 2 to 3 hours before, avoiding fat, excess fiber and anything new. During: water on any effort, and 30 to 60 g of carbs per hour once you go past ~75-90 min (gels, drinks, dried fruit). After: within the following hours, carbs + ~20-25 g of protein plus hydration to kick-start recovery. The marathon "wall" is often a carb shortage: you can plan around it.

Nutrition is the invisible fuel behind your performance. You can have the best training plan in the world, but if you start on an empty stomach or neglect carbs on a long effort, your body will make you pay. Good news: the principles are simple and apply to every level.

This BPMoov guide covers the essentials — before, during, after — with a practical chart by distance, from 10K to marathon, road and trail.

Before the race: fuel up without weighing yourself down

The goal of the pre-race meal is to top up your glycogen stores (the stored form of carbs) without sitting heavy in your stomach.

• Timing: have your last real meal 2 to 3 hours before the start. That's the sweet spot to have digested while keeping energy available.
• Composition: mostly easy-to-digest carbs (bread, rice, pasta, oats, banana), a small protein source, low fat.
• Avoid: fat and fried foods (slow digestion), excess fiber (gut discomfort) and anything new you've never tested in training.

If you run early and eating 3 hours before is impossible, have a light carb snack 60-90 min before (banana, toast with honey, fruit puree). Always test your strategy in training before race day.

On hydration, drink normally in the hours beforehand, without forcing it right before the start.

During the race: water first, carbs next

The rule depends mostly on the duration of the effort, not distance alone.

• Short efforts (< ~75 min, like a 10K): your glycogen stores are enough. Water does the job; no gels needed in general, except in serious heat.
• Long efforts (> ~75-90 min, fast half, marathon, trail): take in 30 to 60 g of carbs per hour, spread out regularly rather than all at once.

In what form? Energy gels, carb drinks, fruit chews, dried fruit... the choice is personal. Two golden rules:

• Always take gels with water. A gel taken "dry" slows digestion and causes gut trouble.
• Start early, not too late. Waiting until you're hungry or fading is already too late: start fueling within the first hour on a long effort.

In practice: scout your race's aid stations in advance (water, drinks, solid food) to lock in your strategy. You can follow the details of your favorited races in the app. → Download BPMoov.

The marathon "wall": why it happens and how to avoid it

The famous "wall" (around km 30-35) usually corresponds to a depletion of glycogen stores. Out of readily available carbs, the body slows down sharply and the mind wavers.

To avoid it, two levers:

• Fuel ahead of time: don't wait for fatigue to eat; aim for 30-60 g of carbs/h from the start of the effort, regularly.
• Prepare the body: long runs in training teach your system to draw efficiently on its reserves and tolerate fueling on the move. It's one of the pillars of good marathon preparation.

A good nutrition strategy doesn't replace training, but a bad one can ruin months of preparation.

After the race: the recovery window

Once you cross the line, your body has three needs: rebuild glycogen, repair muscle fibers, and rehydrate.

• Carbs: replenish depleted stores. The longer the effort, the more it matters.
• Protein: aim for about 20-25 g in the following hours to support muscle repair.
• Hydration: drink regularly to make up for losses; add a little salt/electrolytes if you sweated heavily.

The idea of a very narrow "window" is often overstated, but eating a balanced meal combining carbs and protein within a few hours of the effort remains a good habit. To go further, see our complete guide to post-race recovery.

Trail specifics: aid stations and solid food

Trail changes the game. Efforts are longer, more varied in intensity, and aid stations often dot the course.

• More solid food: on very long efforts, the stomach gets sick of sugary gels. Alternate with savory and solid food (dried fruit, bars, sometimes broth, cheese, salty crackers depending on tolerance).
• Use the aid stations: they're a real resource. Know in advance what they offer so you can complement with what you carry.
• Hydrate for heat and elevation: a hilly trail in hot weather sharply increases fluid losses.

If you're new to the trails, our first trail guide also covers organizing your aid-station strategy.

Practical chart by distance

A few references by target distance:

These figures are reference ranges, to individualize and test in training. Your gut tolerance is personal.

Dialing in your nutrition for your next race? Find the goal first: BPMoov gathers road and trail race registrations across France and Europe — free, iOS and Android, 2,000+ races from 10K to marathon. → Download BPMoov.

FAQ — Runner nutrition

What should you eat before a race?

A meal rich in easy-to-digest carbs (pasta, rice, bread, banana, oats), low in fat and fiber, eaten 2 to 3 hours before the start. If you run early in the morning, go for a light carb snack 60-90 min before. Avoid anything new on race day: always test your strategy in training first.

Do you need gels during a race?

It depends on duration. On a short effort (under ~75 min, like a 10K), water is enough. Beyond ~75-90 min (marathon, trail, fast half), aim for 30 to 60 g of carbs per hour, as gels, drinks or dried fruit. Always take gels with water and start fueling early, not when fatigue hits.

How many carbs per hour on a long effort?

The recognized reference range is 30 to 60 g of carbs per hour on efforts beyond ~75-90 minutes. Spread the intake regularly rather than all at once. Beyond that, some trained runners tolerate more, but it requires specific gut training and remains individual.

What is the marathon "wall" and how do you avoid it?

The "wall" (often around km 30-35) usually corresponds to a depletion of glycogen stores: out of carbs, the body slows down sharply. To avoid it, fuel regularly from the start (30-60 g of carbs/h) without waiting for fatigue, and prepare your body with long runs in training.

What should you eat after a race to recover well?

In the following hours, combine carbs (to rebuild glycogen) and about 20-25 g of protein (for muscle repair), with good hydration. A standard balanced meal does the job nicely. The longer the effort, the more the carb refuel and hydration matter.

Is trail nutrition different from road?

Yes. Trail efforts are longer and the stomach gets sick of sugary gels faster. Favor a mix of carbs, solid and savory food (dried fruit, bars, sometimes broth or salty crackers), use the aid stations along the course, and adapt hydration to heat and elevation. Always test your foods in training.