Marathon Nutrition Guide
Marathon Nutrition Guide
Practical race nutrition guidance for carbohydrate loading, race fueling, hydration and gut training, including before, during and after race advice.
Before The Race
- Practice your race breakfast during long-run training.
- Increase carbohydrate intake in the final days before the race if appropriate.
- Keep race-week foods familiar and easy to digest.
During The Race
- Start fueling early and follow a practiced schedule.
- Use gels, chews or sports drink you have tested in long runs.
- Aim for steady carbohydrate intake rather than waiting for fatigue.
After The Race
- Rehydrate gradually and include sodium if you lost a lot of sweat.
- Eat carbs and protein after finishing, even if appetite is low.
- Return to normal meals as your stomach settles.
Hydration
- Plan fluids around weather, sweat rate and aid-station spacing.
- Use electrolytes when conditions or sweat loss demand them.
- Avoid both dehydration and forced over-drinking.
Common Mistakes
- Trying new fuel on race day.
- Waiting until halfway to begin fueling.
- Skipping gut training during long runs.
Race-Day Timing
- 2-4 hours before: eat a practiced carbohydrate-focused breakfast.
- 10-20 minutes before: optional small carb top-up if you have tested it.
- During the race: start early and aim for a practiced carbohydrate schedule rather than waiting for fatigue.
- After the race: rehydrate gradually and eat carbs plus protein as appetite returns.
Practice The Plan
- Train your gut by practicing fuel during long runs and marathon-pace blocks.
- Use the exact brands, flavors and timing you expect on race day.
- If targeting more than 60g carbohydrate per hour, build gradually and consider mixed carbohydrate sources.
Practical fueling targets
These are practical ranges, not prescriptions. Adjust for body size, tolerance, weather, sweat rate and expected finish time.
| Situation | Target | Notes |
|---|---|---|
| First marathon or sensitive stomach | 30-45g carbohydrate per hour | Start here in training, then build only if tolerated. |
| Practiced marathon fueling | 45-75g carbohydrate per hour | Many runners land in this range using gels, chews and sports drink. |
| Advanced practiced intake | 75-90g carbohydrate per hour | Use only if gut-trained, ideally with mixed carbohydrate sources. |
Example Fueling Plans
- 4 hour marathon: A gel every 30-35 minutes often lands near 40-60g carbohydrate per hour, depending on gel size.
- 3 hour marathon: A practiced plan might combine gels and sports drink to reach roughly 60-75g carbohydrate per hour.
- 5 hour marathon: Use a steady schedule from early in the race, such as 30-45g carbohydrate per hour plus planned fluids.
Fluid And Electrolytes
- Plan fluid around sweat rate, course aid stations and weather.
- Use sodium/electrolytes when sweat loss, heat or salty sweat makes them useful.
- Avoid forced over-drinking; excessive fluid can be dangerous.
Methodology
How this nutrition guidance is written
- Nutrition guidance focuses on practical race-day planning: familiar foods, carbohydrate timing, hydration and recovery.
- Fueling needs vary by body size, sweat rate, climate, tolerance and expected finish time, so the guide favors ranges and practice over one fixed prescription.
- The guides are educational sports-nutrition content, not medical nutrition therapy.
Sources reviewed
- Sports Dietitians Australia distance running factsheet - Reference for distance-running fueling, including carbohydrate guidance for half marathon and marathon racing.
- Sports Dietitians Australia eating and drinking during exercise factsheet - Reference for practical carbohydrate intake ranges during endurance exercise.
- IOC consensus statement on exercise in hot and cold environments - Reference for heat, hydration and carbohydrate considerations during longer exercise.
- Victorian Institute of Sport endurance fueling guidance - Reference for practical 30-60g carbohydrate-per-hour guidance in endurance events.
Last updated June 2, 2026 by the PaceConverter editorial team. Read the editorial policy.
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Frequently asked questions
What should I eat before a Marathon race?
Use familiar carbohydrate-focused foods before a Marathon race. The exact amount depends on race time, duration, tolerance and how close the meal is to the start.
Do I need fuel during a Marathon race?
Start fueling early and follow a practiced schedule.
Should I practice Marathon race nutrition?
Yes. Practice your nutrition and hydration approach before important races so race day feels familiar.