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.

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 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.
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.
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:
At the same time, slightly reduce your intake of fats and protein to avoid overloading your digestive system.
Avoid:
These can all increase the risk of digestive discomfort on race day.
The most important meal isn't breakfast on race morning—it's dinner the night before.
A recommended meal includes:
Avoid:
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.
Timing is essential.
Eat breakfast 2½–3 hours before the start.
Choose easily digestible carbohydrates, such as:
Include a light protein source:
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:
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.
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.
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
Always take gels with a small amount of water to improve digestion.
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.
Everything you plan to eat or drink during the marathon should be tested during training.
During your long runs:
Never assume your stomach will tolerate something you've never used before.
Within 30 minutes of finishing:
Consume a recovery drink containing:
Within the following hour:
Eat a meal combining carbohydrates and protein, for example:
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.
For 5–7 days:
For a complete recovery strategy, also read our week-by-week marathon recovery guide.
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.
▸ Start My Marathon Training Plan
→ 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
→ When Should You Change Your Running Shoe Model?
→ Running Pace Calculator: Complete Pace Charts for Every Distance
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