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Your race plan
Enter your race. You see how much to eat and drink on the way, when, and which pace fits your target time. Save the plan as an image on your phone.
21.1 km in 2:15:00 · 6:24 per km
Eating on the way
60 g carbohydrate per hourSource 1Source 2
About 135 g in total.
That is about 5 gels.
Calculated with a typical gel of 25 g. What you carry may differ, check the pack.
At this amount a mix of two sugars helps, glucose and fructose. With one sugar alone your gut cannot keep up.
Your gut can learn to take up to about 90 g per hour. Build up to it in training, not on race day.
Drinking
For drinking, salt and the meals before and after we need your weight.
When
Start early and take something regularly, not only once you feel hungry.
- After 0:20at km 3.127 g≈ 1 gel
- After 0:45at km 727 g≈ 1 gel
- After 1:10at km 10.927 g≈ 1 gel
- After 1:35at km 14.827 g≈ 1 gel
- After 2:00at km 18.827 g≈ 1 gel
Pace
An even 6:24 per km. This is how it looks at each mark:
- 5 km32:00
- 10 km1:03:59
- Halfway1:07:30
- 15 km1:35:59
- 20 km2:07:59
- Finish2:15:00
Saves your plan as an image on your phone. Set it as your lock screen and it is there at a glance during the race.
Try your fueling in training, not for the first time in the race.
Latu is not a doctor. These numbers are a guide from sports science, not medical advice. If you have symptoms or a condition, talk to someone who knows about it first.
For many races in 2027 we show you the Monday your training starts: Races 2027.
How much for which duration and pace is in the table Carbs per hour. The zones calculator works out your heart-rate, pace and power zones.
Questions about fueling in a race
The numbers come from the same calculator as your plan above, for typical races at race pace.
How many carbs per hour in a marathon?
Run 3:30 at race pace and Latu plans 90 g of carbohydrate per hour, about 315 g in all. At 3:00 it is 75 g per hour, because the recommendation only rises from about two and a half hours on. That much takes a mix of glucose and fructose, and your stomach should have practised it in training.Source 1Source 2
When should I take a gel in a marathon?
Early and regularly. The race plan sets the first point at 20 minutes, then one every 25 minutes, and none in the last 10 minutes. At 3:30 that is 8 points of about 39 g of carbohydrate each, roughly 1.5 typical gels of 25 g. Try the rhythm on your long run.Source 1Source 2
Do I need a gel in a half marathon?
Usually, yes. If your race lasts longer than an hour, Latu plans carbohydrate on the way. For a half marathon in 2:00 that is 60 g per hour, about 120 g in all, roughly 5 typical gels. A 10 km race in 50 minutes, on the other hand, you run on water.Source 1Source 2
How many carbs per hour when cycling?
It depends on duration and pace. For two hours at a moderate pace Latu plans 45 g per hour, at race pace 60 g. Ride five hours at race pace and it is 90 g per hour from glucose and fructose. Your stomach handles large amounts only with practice, so try them in training, not first in the race.Source 1Source 2
Why not just 120 g per hour?
Some professionals take that much in races. A 2026 review considers 120 g possible for trained athletes. A second paper and the cycling world governing body’s position statement say the benefit is not yet shown. So Latu plans at most 90 g per hour. 120 g is a ceiling nobody has to reach. Your stomach sets the limit.Source 1Source 2
Latu builds the plan up to the start.
Latu plans your weeks up to the race, fits them around your life and works out the fueling for every session. You have the last word.
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