Marathon nutrition strategy
A practical race-day plan for carb loading, hourly fueling, hydration, and recovery, built on sports nutrition evidence for runners in the US and Canada.
Written by Victura Nutrition TeamReviewed by Victura Editorial ReviewLast updated Oct 20, 2026
Quick answer
Most runners use gels, chews, sports drinks, bananas, dates, or pretzels in small, frequent doses of about 30 g of carbohydrate every 20 to 30 minutes. Whole foods such as 60 g (half) of a banana or 40 g (1/4 cup) of raisins work well when they have been tested in training. Aim for 60 to 90 g of carbohydrate per hour in total, counting both food and drink.
A practical race-day plan for carb loading, hourly fueling, hydration, and recovery, built on sports nutrition evidence for runners in the US and Canada.
Key takeaways
- Carb load 8 to 12 g per kg of body weight daily for 36 to 48 hours before racing.
- Target 60 to 90 g of carbohydrate per hour during the marathon, practiced in training.
- Drink 400 to 800 ml (14 to 27 oz) per hour and avoid gaining weight while running.
- Eat 100 to 150 g of carbohydrate 2 to 3 hours before the start of the race.
- Refuel within 30 minutes of finishing with carbohydrate plus 20 to 40 g of protein.
The evidence-based marathon fueling plan
Research-backedWhy 42 km is a fueling problem
A marathon is a fueling problem before it is a fitness problem. Most runners store roughly 1,800 to 2,000 kcal of glycogen in muscle and liver, while 42.2 km (26.2 mi) can burn 2,600 to 3,000 kcal or more depending on body size and pace. When glycogen runs low, pace collapses and perceived effort spikes, which is what runners describe as hitting the wall.
That reality shapes the whole plan. You want to start with full tanks, top them up at a rate your gut can actually absorb, and begin refilling the moment you stop running.
Key takeaway: Practice every food, gel, and drink in training first; race day is not the place for a new product.
Carb loading in the final 72 hours
Carb loading means raising carbohydrate intake while cutting training volume. Sports nutrition guidance supports roughly 8 to 12 g of carbohydrate per kilogram of body weight per day in the 36 to 48 hours before a race. For a 70 kg (154 lb) runner, that is about 560 to 840 g per day, which is far more food than most people normally eat.
Keep those carbs low in fiber, fat, and spice so they empty from the stomach quickly. Reliable options, with portions:
- White rice: 200 g cooked (1 cup) per meal
- Pasta with light tomato sauce: 250 g cooked (1.5 cups)
- White bagel: 100 g (1 medium) with 20 g honey (1 tbsp)
- Sweet potato: 200 g (1 large) baked, skin removed
- Banana: 120 g (1 medium), two to three per day
- Orange juice: 240 ml (8 oz) with breakfast
- Oatmeal: 240 g cooked (1 cup), made from 40 g dry (1/2 cup) oats plus 20 g honey (1 tbsp)
- Sports drink or juice between meals: 500 ml (17 oz)
Raw vegetables, beans, and large amounts of nuts are better saved for after the race. They are healthy foods, but they add fiber and fat at the exact moment you want easy digestion.
Race morning: the last real meal
Eat 2 to 3 hours before the start if your schedule allows, and keep the meal identical to what worked in long training runs. A workable target is 100 to 150 g of carbohydrate with very little fat or protein.
One example: a 100 g (1 medium) bagel with 20 g (1 tbsp) honey, one 120 g (1 medium) banana, and 400 to 500 ml (14 to 17 oz) of water or a weak sports drink. If you cannot eat that early, shift to 30 to 60 g of carbohydrate 60 to 90 minutes out, such as one gel (30 g carbohydrate) with 240 ml (8 oz) water.
Coffee is fine if you already drink it before training runs. New supplements, high-dose caffeine, and unfamiliar energy drinks are not worth the risk on race morning.
Fueling timeline for race day
| When | What to eat | Portion (g + US units) | Why |
|---|---|---|---|
| Night before, 12 to 16 hours out | Pasta or rice with lean protein and cooked vegetables | 250 g cooked pasta (1.5 cups) plus 115 g chicken (4 oz) | Tops off liver glycogen without a heavy gut load |
| 3 hours before the start | White bagel with honey and a banana | 100 g bagel (1 medium) plus 20 g honey (1 tbsp) plus 120 g banana (1 medium) | Leaves time for the stomach to empty |
| 60 to 90 minutes before | Gel with water, or a banana | 30 g gel (1 packet) plus 240 ml water (8 oz) | Raises blood glucose without a rebound dip |
| 0 to 15 minutes, at the start | Small sips of fluid | 200 to 300 ml (7 to 10 oz) | Starts you hydrated without sloshing |
| Every 20 to 30 minutes, first half | Gel, chews, dates, or banana | 30 g carbohydrate (1 gel, or 40 g pitted dates, or 60 g banana) | Spreads absorption and limits gut stress |
| Every aid station | Sports drink plus water | 150 to 250 ml (5 to 8 oz) of each | Delivers fluid, sodium, and carbohydrate together |
| Final 30 to 45 minutes | One gel or a few chews | 30 g carbohydrate (1 gel) | Keeps blood glucose up through the last push |
| 0 to 30 minutes after finishing | Chocolate milk or a recovery drink | 500 ml (17 oz) | Carbohydrate plus protein begins glycogen refill |
| 1 to 3 hours after finishing | Rice bowl with chicken and cooked vegetables | 200 g cooked rice (1 cup) plus 115 g chicken (4 oz) | Rebuilds glycogen and supports muscle repair |
Carbs, fluid, and sodium during the race
Carbohydrate intake is the single biggest lever. General guidance is 30 to 60 g per hour for events lasting about 1 to 2.5 hours, rising to 60 to 90 g per hour for longer efforts such as the marathon when the gut is trained and the products use mixed glucose and fructose. Two gels per hour, or one gel plus 500 ml (17 oz) of a 6 percent sports drink, lands near 60 g per hour.
Fluid needs vary widely with heat, sweat rate, and body size. A practical range is 400 to 800 ml per hour (14 to 27 oz), sipped steadily rather than gulped. Drinking far beyond thirst and gaining weight during a race is a real risk, so let thirst and the climate guide you.
Sodium matters for heavy, salty sweaters, especially in heat. Roughly 300 to 600 mg of sodium per hour from sports drinks, chews, or electrolyte capsules covers most runners, but check the label so carbohydrate and sodium are not double counted.
To protect your stomach, split intake into small frequent doses, avoid high-fat or high-fiber foods mid-race, and take gels with water rather than a concentrated sports drink.
Recovery after the finish line
The first hour after the race is the most efficient window for refilling glycogen. Aim for about 1.0 to 1.2 g of carbohydrate per kilogram plus 20 to 40 g of protein, then repeat a normal meal within 1 to 3 hours. For a 70 kg (154 lb) runner, that means roughly 70 to 85 g of carbohydrate and 25 g of protein, such as 500 ml (17 oz) of chocolate milk followed by a rice and chicken bowl.
What runners actually do on race day
Community insightPatterns from real training blocks
Anonymized Victura meal logs show a consistent gap between plans and practice. Runners who rehearse their gel schedule on long runs report far fewer stomach problems than those who try a fueling plan for the first time on race day. The most common fix is simple: set a repeating timer for every 30 minutes and take fuel before hunger or fatigue appears.
Breakfast is the other recurring theme. Runners who eat 100 to 150 g of carbohydrate two to three hours before the start describe steadier early miles than those who run on coffee alone.
Habits that tend to backfire
- Cramming all gels into the final 10 km instead of spreading them across the race
- Drinking large volumes at aid stations and feeling bloated for the next kilometer
- Trying a new sports drink, chews, or caffeine dose on race morning
- Skipping the recovery meal because appetite disappears after a hard effort
The runners who report the smoothest races usually carry their own fuel, know exactly what each aid station offers, and treat the plan as something they have already tested a dozen times in training.
Practical habits worth copying
Pack gels in a numbered sequence so you know where you are in the schedule. Write your carbohydrate target in grams per hour on your hand or watch, not just the number of packets. Take a few sips at every station instead of waiting until you feel thirsty. Choose portable whole foods when they work for you, such as a banana at 120 g (1 medium), 40 g (about 1/4 cup) of raisins, or 30 g (1 oz) of pretzels alongside your gels.
After the finish, set a reminder for the recovery meal, because appetite is unreliable in the first hour. A 500 ml (17 oz) bottle of chocolate milk is easy to keep in a gear bag and covers carbohydrate and protein together.
References
- Nutrition and Athletic Performance: Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine(pubmed)
- IOC consensus statement on sports nutrition and supplements for the elite athlete(pubmed)
- Carbohydrates for training and competition (Burke et al., Journal of Sports Sciences)(pubmed)
- A step towards personalized sports nutrition: carbohydrate intake during exercise (Jeukendrup)(pubmed)
- ACSM position stand: Exercise and fluid replacement(pubmed)
- USDA FoodData Central: nutrient values for grains, fruits, and sports foods(usda)
- NIH Office of Dietary Supplements: Exercise and Athletic Performance(nih_ods)
- Harvard T.H. Chan School of Public Health: Carbohydrates and sports performance(harvard)
- Victura anonymized meal logs: race-day fueling patterns(victura)
Frequently asked questions
People also ask
What should I eat during a marathon?
Most runners use gels, chews, sports drinks, bananas, dates, or pretzels in small, frequent doses of about 30 g of carbohydrate every 20 to 30 minutes. Whole foods such as 60 g (half) of a banana or 40 g (1/4 cup) of raisins work well when they have been tested in training. Aim for 60 to 90 g of carbohydrate per hour in total, counting both food and drink.
How many carbs per hour should I take during a marathon?
General sports nutrition guidance is 30 to 60 g of carbohydrate per hour for events of about 1 to 2.5 hours, and up to 90 g per hour for longer races such as the marathon when the gut is trained and products combine glucose and fructose. Most marathoners do well at 60 to 80 g per hour. Build up to that intake during long training runs rather than starting on race day.
When should I start carb loading before a marathon?
Begin in the 36 to 48 hours before the race, and some runners extend it to 72 hours. Targets are roughly 8 to 12 g of carbohydrate per kilogram of body weight per day, which is about 560 to 840 g daily for a 70 kg (154 lb) runner. Keep fiber, fat, and spice low so the food digests easily.
How many gels should I take during a marathon?
It depends on your hourly target and what the aid stations provide. At 60 g of carbohydrate per hour with 30 g gels, a four-hour marathon needs about 240 g, or eight gels total, minus whatever comes from sports drink. Start within the first 30 minutes and space them every 30 to 40 minutes instead of saving them for the final miles.
Should I eat breakfast before a marathon?
Yes. Eat 100 to 150 g of carbohydrate roughly 2 to 3 hours before the start, with very little fat, fiber, or protein. A white bagel (100 g) with 20 g (1 tbsp) honey and a 120 g banana is a common choice. If you cannot eat that early, take 30 to 60 g of carbohydrate 60 to 90 minutes before the gun.
How do I avoid stomach issues during a marathon?
Rehearse your exact race-day foods in training, keep fiber and fat low on race morning, and split carbohydrate into small doses every 20 to 30 minutes. Take gels with water rather than a concentrated sports drink, sip fluids steadily instead of gulping at stations, and avoid overdrinking. Any product that caused discomfort in training should stay out of the race plan.
How much sodium and fluid do I need during a marathon?
Most runners need about 400 to 800 ml (14 to 27 oz) of fluid per hour, adjusted for heat, sweat rate, and body size. Sodium needs are commonly 300 to 600 mg per hour for salty sweaters, taken through sports drinks, chews, or electrolyte supplements. Drinking far beyond thirst and gaining weight during the race is unsafe, so let thirst guide you.
Do I need protein during a marathon?
No. Carbohydrate is the priority during the race because glycogen, not protein, is the limiting fuel. Protein matters before and after: 20 to 40 g within the first hour after finishing supports muscle repair, ideally paired with about 1.0 to 1.2 g of carbohydrate per kilogram of body weight to start glycogen refill.
What is the best marathon nutrition strategy?
Start with carb loading at 8 to 12 g of carbohydrate per kilogram of body weight daily for 36 to 48 hours, eat 100 to 150 g of carbohydrate 2 to 3 hours before the start, then take 60 to 90 g of carbohydrate per hour during the race with 400 to 800 ml of fluid per hour. Refuel within 30 minutes of finishing with carbohydrate plus 20 to 40 g of protein. Practice every food and drink in training first.
How many calories do you burn during a marathon?
A marathon burns roughly 2,600 to 3,000 kcal or more depending on body size and pace, while most runners store only about 1,800 to 2,000 kcal of glycogen. That gap is why in-race carbohydrate intake of 60 to 90 g per hour matters, and why hitting the wall is a fueling problem rather than only a fitness problem.
What should I eat the night before a marathon?
Choose a familiar, low-fiber, low-fat meal 12 to 16 hours before the start, such as 250 g (1.5 cups) of cooked pasta or rice with 115 g (4 oz) of lean chicken and cooked vegetables. The goal is to top off glycogen without a heavy gut load, and to avoid trying any new food the night before a race.
How we review this guide
- Written by
- Victura Nutrition Team
- Reviewed by
- Victura Editorial Review
- Reference sources
- 11
- Last updated
- Oct 20, 2026
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