How to fuel a half-marathon
A half-marathon takes 1 h 20 to 2 h 30 depending on level, at a higher intensity than the marathon. Over that duration, glycogen stores aren't the limiter they become in a marathon — but a targeted carb intake, around 30 to 60 g/h, clearly helps hold pace over the second half. The real challenge is light, well-tolerated fuelling that doesn't overload a stomach already stressed by the intensity.
During: 30-60 g/h is enough
In a half, most runners take just 1 to 2 carb feeds — 30 to 60 g/h. A gel around 7-8 km then another around 14-15 km covers the second half well, when pace gets hard to hold. Take them with water at an aid station rather than with a sports drink, to avoid too strong a concentration. Fast runners (under 1 h 30) can get by on a single gel or a carb drink.
Before the race
You don't need a carb load as heavy as for a marathon: a normally carb-rich day beforehand is enough. On the morning, a digestible 2-3 g/kg meal eaten 3 hours before the start tops up liver glycogen. Depending on start time, a small feed 15 minutes before (gel or fruit purée) can give a final boost. Sip an electrolyte drink while you wait, especially in the heat.
Your fuelling timeline
Race day — Half-Marathon fueling timeline (target 1 h 30 / 2 h)
Before: digestible H-3 meal + light hydration while waiting
During: 30-50 g/h carbs + water at aid stations
After: rehydrate + full meal within 2 hours
Rice pudding with honey
or toast with jam
+ 250 ml water
1 standard energy gel
+ water from aid station
1 standard energy gel
or digest-friendly caffeine gel
+ water
Light recovery shake
or water + meal within 2 hours
This plan calls for 2 gels. Take them right before an aid station to wash them down with plain water.
After the half
Recovery is lighter than after a marathon, but the principle holds: rehydrate, then take carbs and some protein within the hour if you're training again. A proper meal within two hours is enough to reload.
Your quick plan
- Normally carb-rich day beforehand
- Digestible 2-3 g/kg meal eaten 3 h before
- 1 to 2 gels planned (around 7-8 km and 14-15 km)
- Water with each gel
- Products tested on a long run beforehand
Common mistakes
- Over-fuelling as if for a marathon and loading the stomach at high intensity
- Taking your single gel too late, once pace is already dropping
- Testing an unknown gel on race day
- Neglecting hydration in the heat on a "short" race
- Starting too fast and losing your stomach by 5 km
FAQ
Related articles
How many gels for a marathon?
The right amount mostly depends on your finish time, your carbs-per-hour target and your digestive tolerance.
Read the guideHow to test your nutrition before a race
Race nutrition is tested in training, especially on long sessions and workouts close to race conditions.
Read the guide