Long-distance running events reward patience, pacing, and the kind of steady effort that feels easy until it doesn’t. Most mid-race blowups don’t come from weak legs. They come from an empty tank, a sloshing stomach, or a plan that looked fine on paper but fell apart at mile 14.

This article lays out how to fuel for long-distance running events with clear, workable steps. You’ll learn what to do in the days before a race, what to eat on race morning, how to take in carbs and fluids while you run, and how to practice it so it feels boring on race day (boring is good).

Start with the basics: your body runs on carbs (mostly)

At long distances, you rely on a mix of fat and carbohydrate. The problem: you store far less carbohydrate than fat. Your muscles and liver hold a limited supply of glycogen, and once it runs low, pace and focus drop fast. That’s the “wall” many marathoners talk about.

You can’t fully avoid fatigue, but you can slow the slide by keeping carbs coming in. That’s the core idea behind fueling for long-distance running events: protect glycogen, keep blood sugar steady, and avoid gut trouble.

If you want the science standards behind carb targets, the Gatorade Sports Science Institute’s review on carbs during exercise gives a solid overview of how intake supports performance. For broader guidelines, the Academy of Nutrition and Dietetics sports nutrition resources are also helpful.

Build your fuel plan around three time windows

Most runners think about gels and sports drink. That’s only one slice of the plan. Strong fueling has three parts:

• Before the race (the week and the last 24 hours)
• Race morning (the last 1-4 hours)
• During the event (carbs, fluids, sodium)

Get these in place, then you can tweak details like brand, flavors, and exact timing.

The week before: don’t “eat clean,” eat useful

The week before a long race is not the time for surprise habits. Keep fiber, fat, and spicy foods in a range you know your gut can handle. Keep training stress in mind too. As your taper begins, you’ll burn fewer calories, but you still need carbs to top off glycogen.

Carb-loading without the mess

Carb-loading doesn’t mean a single giant pasta dinner. That often backfires with bloating and a bad night of sleep. Instead, raise carbs for 1-3 days before the event, spread across meals and snacks.

Useful carb-heavy foods that tend to sit well:

• Rice, potatoes, oats, and pasta
• Bagels, toast, English muffins
• Bananas, applesauce, canned fruit
• Low-fiber cereal with milk or yogurt (if dairy works for you)

Keep protein in the mix, but don’t let it crowd out carbs. Keep fats moderate. High-fat meals can feel heavy and slow digestion.

Hydration in the days before

Most runners don’t need extreme water loading. Aim for pale yellow urine and steady intake through the day. Add salt to meals if you tend to sweat a lot or if the weather will be hot. If you want a plain-English take on hydration and heat risk, the CDC’s heat stress guidance covers warning signs and why heat changes hydration needs.

The last 24 hours: reduce gut risk

The day before a race, choose foods you’ve eaten before long runs. This isn’t the time for a new restaurant or a “healthy” bean bowl that triples your fiber.

A simple pre-race day template

• Breakfast: oats with banana and honey, or toast plus eggs
• Lunch: rice bowl with chicken, soy sauce, and a small portion of cooked veggies
• Snack: pretzels, applesauce, yogurt, or a sports drink
• Dinner: pasta or potatoes with a lean protein, keep veggies cooked and modest
• Before bed (if you’re hungry): a bagel, cereal, or a banana

If you’re prone to stomach trouble, reduce very high-fiber foods, big salads, and heavy cream sauces. You don’t need to eliminate all fiber, just avoid a sudden jump.

Race morning: eat early, keep it simple

A good race breakfast gives you carbs, a little protein, and low fiber. Most runners do well eating 2-4 hours before the start. If your nerves kill appetite, aim for something small and liquid-friendly.

How much to eat

Many runners land around 1-4 grams of carbohydrate per kilogram of body weight in the 1-4 hours before exercise. That’s a wide range because stomach tolerance and start time matter. If you’ve never practiced it, stay conservative.

Examples:

• Bagel with jam + banana
• Oatmeal + honey + a few sips of sports drink
• Toast + peanut butter (if fat sits well for you) + fruit
• Rice or potatoes with a little salt (surprisingly solid for some people)

Caffeine: useful, but practice it

Caffeine can help perceived effort and focus, but it can also upset your stomach. Keep the dose familiar and timed. Many runners take it 30-60 minutes before the start, or split it across the race with caffeinated gels. If coffee makes you sprint to the bathroom, don’t force it on race day.

During the race: carbs first, then fluids and sodium

For most long races, your mid-race fuel is the main event. Your goal is steady intake you can repeat, not a heroic gel binge at mile 20.

Carb targets that work in the real world

For events longer than about 90 minutes, most runners do well with 30-60 grams of carbs per hour. Many can handle 60-90 grams per hour if they train their gut and use mixed carb sources (like glucose plus fructose). If that sounds technical, keep it simple: start at 30-45 grams per hour and build.

Common carb amounts:

• Most gels: 20-25 grams each
• Most chews (per serving): 20-40 grams
• Sports drink (500 ml): often 30-40 grams, check the label

A simple starting plan for fueling for long-distance running events:

• Take in 1 gel every 30-40 minutes (or the equivalent in drink/chews)
• Start early, around 20-30 minutes in
• Use water to wash down gels unless the gel is designed to be taken without water

If you like more precision, use a carb calculator. The carb intake calculator from MySportScience is a practical tool to turn targets into an hourly plan.

Fluids: drink to a plan, then adjust

Hydration advice gets messy because sweat rates vary a lot. Still, you can build a strong plan with two steps:

1. Estimate your sweat rate in training (weigh before and after a run, adjust for what you drank).
2. Use that number to guide how much you drink per hour, then adjust for heat, pace, and thirst.

A common range is 400-800 ml per hour, but your number might sit outside that. The goal isn’t to “stay ahead” of sweat at all costs. It’s to avoid dehydration that hurts performance without overdrinking.

Overdrinking can cause hyponatremia (low blood sodium), which is dangerous. The Mayo Clinic overview of hyponatremia explains why too much fluid can be a problem.

Sodium: the missing piece for heavy sweaters

Some runners lose a lot of sodium in sweat and feel awful without it. Signs you may need more sodium include:

• White salt streaks on clothing or skin after runs
• Cramping that tracks with heat and sweat loss
• Feeling weak, dizzy, or nauseated late in hot races (not always sodium, but it can play a role)

You can get sodium from sports drink, gels (some include it), salt tabs, or salty foods at aid stations (pretzels, broth). Avoid huge doses if you haven’t tested them. Start with what your sports drink already provides, then adjust.

Train your gut like you train your legs

Many runners can hit higher carb targets if they practice. Your gut adapts. If you only take gels on race day, you increase the odds of nausea, cramps, or emergency bathroom stops.

How to practice fueling in long runs

• Use key long runs to rehearse race-day timing and products.
• Start with a low dose (like 30 grams per hour), then add 10-15 grams per hour every 1-2 weeks if you want more.
• Practice in similar conditions: heat, hills, and race pace make fueling harder.
• Keep notes: what you took, when, weather, and how your stomach felt.

If you want deeper detail on endurance fueling and “train the gut” ideas, TrainingPeaks’ breakdown of carbs per hour offers a coach-friendly view without medical language.

Choose fuel forms you’ll actually use

You don’t need fancy products. You need carbs you can carry and tolerate.

Gels, chews, drink mix, or real food?

• Gels: easy to track, fast carbs, can taste intense late in races.
• Chews: easier for some to eat, harder to chew when breathing hard.
• Sports drink: combines carbs and fluid, but you may underdose carbs if you drink less than planned.
• Real food: works well in ultras or slower events (bananas, potatoes, rice balls), but needs more chewing and planning.

For marathons and half marathons, gels plus water is the simplest system. For ultras, many runners mix gels, drink mix, and small salty foods to avoid flavor fatigue.

Common fueling mistakes (and how to avoid them)

Waiting until you feel tired to eat

By the time you feel the dip, you’re late. Start early and stay steady. Set a watch alert if you need it.

Trying a new product on race day

If you want to test a new gel, test it on a long run first. Taste and texture matter more than you think when you’re hot and tired.

Mixing too many things at once

When you combine a new gel, a new sports drink, and a new breakfast, you won’t know what caused the problem. Change one variable at a time in training.

Ignoring the weather

Heat raises fluid needs and can make your stomach more sensitive. In hot conditions, you may need to lower pace a bit and use more fluid-based carbs.

Going too low-carb because you “want to be fat-adapted”

Some training sessions can work well with lower carb, but race day is different. If you want to perform, you need carbs. Even many low-carb advocates use carbs in races because intensity demands it.

Fueling plans for common race distances

These are starting points, not rules. Body size, speed, and heat can shift them.

Half marathon (about 90 minutes to 2+ hours)

• Before: normal breakfast 2-3 hours pre-race
• During: 30-60 grams carbs per hour
• Simple plan: 1 gel at 30-40 minutes, another at 70-80 minutes if needed

Marathon

• Before: carb-forward day prior, breakfast 2-4 hours pre-race
• During: 60 grams carbs per hour for many runners, more if trained
• Simple plan: 1 gel every 30-35 minutes, water at aid stations, sodium from drink or tabs if needed

Ultras and long trail events

• Before: carb load still helps, but comfort foods matter more
• During: 60-90 grams carbs per hour if tolerated, plus more sodium and a wider food mix
• Simple plan: alternate sweet and salty, use drink mix when chewing feels hard

Where to start this week

If you want fueling for long-distance running events to feel easy, don’t wait for race week. Use your next two long runs to build a repeatable routine.

1. Pick one carb source you can tolerate (one gel brand or one drink mix).
2. Set a timer for every 30 minutes and take in 20-25 grams of carbs each time.
3. Track fluids: note how many bottles or cups you drank and how you felt.
4. After the run, write down what worked and what didn’t while it’s fresh.

Then adjust one thing at a time. Over a few weeks, you’ll land on a plan you trust. That’s when race day gets simpler: you won’t guess, you’ll follow the script, and you’ll have the energy to run the last miles with intent instead of survival.