Marathon Nutrition: What to Eat Before | StrideMatch

During a marathon, your nutrition can make the difference between achieving your goal and hitting the wall around km 30 (mile 20). It's one of the biggest factors influencing marathon performance—yet it's also one of the most overlooked by recreational runners.

In this guide, you'll learn the complete marathon nutrition strategy—from the week leading up to the race, to your pre-race meal, in-race fueling, hydration, and post-marathon recovery.

The Week Before the Marathon: Carb Loading

The goal during the final 4–5 days before race day is to maximize your muscle and liver glycogen stores. This process is known as carb loading.

7 to 4 Days Before Race Day

Eat your normal, balanced diet.

There's no need to drastically change your eating habits.

Stick with foods your body already knows and tolerates well.

3 to 1 Days Before Race Day: Carb Loading

Gradually increase the proportion of carbohydrates in your meals.

Aim for 8–10 g of carbohydrates per kilogram of body weight per day, instead of the usual 5–7 g/kg.

Example:

A 70 kg runner should consume approximately 560–700 g of carbohydrates per day.

Good carbohydrate sources include:

Pasta
Rice
Bread
Sweet potatoes
Couscous
Polenta
Fruit

At the same time, slightly reduce your intake of fats and protein to avoid overloading your digestive system.

Common Carb-Loading Mistakes

Avoid:

Trying unfamiliar or exotic foods.
Eating excessive amounts of fiber.
Drinking too much alcohol.
Consuming large quantities of raw vegetables.

These can all increase the risk of digestive discomfort on race day.

The Night Before the Marathon

The most important meal isn't breakfast on race morning—it's dinner the night before.

A recommended meal includes:

200–300 g of cooked pasta or rice
A simple sauce (tomato or lightly cooked vegetables)
100–150 g of lean protein (chicken, white fish, or eggs)
Moderate portions of cooked vegetables
White bread
A small amount of olive oil
A carbohydrate-rich dessert such as rice pudding or applesauce

Avoid:

Heavy cream sauces
Fried foods
Spicy meals
Strong cheeses
Fatty processed meats

Stay well hydrated by drinking 500–700 ml of water during and after dinner.

Eat at a reasonable time—around 7–8 p.m.—to allow for proper digestion before bed.

Race Morning Breakfast

Timing is essential.

Eat breakfast 2½–3 hours before the start.

Recommended Breakfast

Choose easily digestible carbohydrates, such as:

White bread with jam or honey
Cooked oatmeal
Rice pudding
A banana
Applesauce

Include a light protein source:

1–2 eggs
Cottage cheese or Greek yogurt
Lean ham

Keep fat intake low.

If you normally drink coffee, one regular cup is fine.

If you don't usually consume caffeine, race morning isn't the time to start.

Hydration:

Around 500 ml of water or weak tea with breakfast.
Another 250–300 ml during the final hour before the start.

The Biggest Mistake: Trying Something New

Never experiment with a new breakfast on race day.

Eat exactly what you've already tested during your marathon training—especially on your long runs.

Marathon Fueling Strategy

During a marathon you'll burn approximately 2,500–3,500 kcal.

Your glycogen stores only provide around 2,000 kcal.

Without carbohydrate intake during the race, hitting the wall becomes highly likely.

Recommended Carbohydrate Intake

Aim for 60–90 g of carbohydrates per hour, depending on your pace and digestive tolerance.

For most runners, this means approximately one energy gel every 30–40 minutes.

Expected Finish Time — Fueling Strategy

Under 3 hours — 4–5 gels (every 35–40 minutes)
3–4 hours — 5–7 gels (every 30–35 minutes)
Over 4 hours — 7–9 gels plus 1–2 energy bars or other solid foods

When to Take Your Gels

First gel: between km 8 and km 10.
Additional gels: every 30–40 minutes.
Final gel: around km 35–37 for a final energy boost.

Always take gels with a small amount of water to improve digestion.

Hydration During the Marathon

Drink at every official aid station—typically every 5 km.

Aim for approximately 100–200 ml each time, taking small sips.

In cool conditions (10–15°C / 50–59°F), water alone is generally sufficient.

In warmer weather, include an electrolyte drink every 2–3 aid stations.

Avoid excessive water intake.

Drinking too much can lead to exercise-associated hyponatremia, a potentially serious medical condition.

Practice Your Nutrition Before Race Day

Everything you plan to eat or drink during the marathon should be tested during training.

During your long runs:

Test every gel brand on at least 2–3 sessions.
Experiment with fueling every 30, 35, or 40 minutes.
If you're racing for more than four hours, try different textures (liquid gels, thicker gels, chews, or bars).

Never assume your stomach will tolerate something you've never used before.

Post-Marathon Nutrition

The First Two Hours

Within 30 minutes of finishing:

Consume a recovery drink containing:

Water
Electrolytes
Carbohydrates
Protein

Within the following hour:

Eat a meal combining carbohydrates and protein, for example:

A sandwich and fruit
Pasta with eggs
Rice with chicken

The Rest of the Day

Continue drinking plenty of fluids.

Aim for approximately 3–4 liters of water throughout the day.

Eat a balanced dinner with 1.5–1.8 g of protein per kilogram of body weight to support muscle repair.

Avoid excessive alcohol, as it significantly slows recovery.

The Following Week

For 5–7 days:

Maintain a high protein intake.
Eat more anti-inflammatory foods such as oily fish (omega-3), turmeric, ginger, berries, and green vegetables.
Drink more fluids than usual for the first 3–4 days.

For a complete recovery strategy, also read our week-by-week marathon recovery guide.

READY TO OPTIMIZE YOUR MARATHON NUTRITION?

Build Your Complete Marathon Preparation Plan

Nutrition, training, and equipment all work together to determine marathon performance. StrideMatch creates a complete marathon plan that includes long runs designed to test your fueling strategy while recommending the running shoes best suited to your target marathon pace.

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→ How Many Kilometres a Week Do You Need to Train for a Marathon?

→ Marathon Taper: How Many Weeks Do You Really Need?

→ 10K Pace for 40 Minutes: Splits and Training Plan

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