Mavr Sports Nutrition Team
Updated October 2, 2026. 10 min read.
Most marathon runners need 6 to 10 gels: take the first one about 20 minutes in, then one every 20 to 25 minutes until about 20 minutes before the finish. Slower runners need more gels in total, but take them a bit further apart.
The chart below shows gels and carbs per hour by finish time. It assumes a standard gel with about 25 g of carbs and no sports drink. If you drink sports drink on the course, take fewer gels.
2:30
Gels (25 g each)6 to 7
Carbs per hour60 to 70 g
When to take themFrom 20 min, every 20 min
3:00
Gels (25 g each)7 to 8
Carbs per hour60 to 65 g
When to take themFrom 20 min, every 20 min
3:30
Gels (25 g each)8 to 9
Carbs per hour55 to 65 g
When to take themFrom 20 min, every 20 to 25 min
4:00
Gels (25 g each)8 to 10
Carbs per hour50 to 60 g
When to take themFrom 20 min, every 25 min
4:30
Gels (25 g each)9 to 11
Carbs per hour50 to 60 g
When to take themFrom 20 min, every 25 min
5:00
Gels (25 g each)9 to 11
Carbs per hour45 to 55 g
When to take themFrom 20 min, every 25 to 30 min
5:30
Gels (25 g each)10 to 12
Carbs per hour45 to 55 g
When to take themFrom 20 min, every 25 to 30 min
6:00
Gels (25 g each)10 to 12
Carbs per hour40 to 50 g
When to take themFrom 20 min, every 30 min
| Finish time | Gels (25 g each) | Carbs per hour | When to take them |
|---|---|---|---|
| 2:30 | 6 to 7 | 60 to 70 g | From 20 min, every 20 min |
| 3:00 | 7 to 8 | 60 to 65 g | From 20 min, every 20 min |
| 3:30 | 8 to 9 | 55 to 65 g | From 20 min, every 20 to 25 min |
| 4:00 | 8 to 10 | 50 to 60 g | From 20 min, every 25 min |
| 4:30 | 9 to 11 | 50 to 60 g | From 20 min, every 25 min |
| 5:00 | 9 to 11 | 45 to 55 g | From 20 min, every 25 to 30 min |
| 5:30 | 10 to 12 | 45 to 55 g | From 20 min, every 25 to 30 min |
| 6:00 | 10 to 12 | 40 to 50 g | From 20 min, every 30 min |
Use the lower number if you are new to gels, have a sensitive stomach, or drink sports drink on course. Use the higher number if you have practiced fueling on long runs and want to push toward 70 to 90 g per hour.
For races longer than about 2.5 hours, sports nutrition guidelines allow up to about 90 g of carbs per hour. That higher end works best with gels or drinks that mix glucose and fructose, and with a gut that has been trained to take them. Most recreational runners do well between 45 and 70 g per hour, which is what the chart is built around.
Your body stores roughly enough glycogen for about 90 minutes to 2 hours of hard running. After that, carbs you take in during the race help you hold pace. Runners who skip fuel often slow sharply in the last 10 km, the well-known wall around mile 20.
Faster runners burn carbs faster, so they need more per hour. Slower runners run at a lower intensity, so they can take a little less per hour, but they are out longer, so the total number of gels goes up.
Check your label. A Maurten Gel 100 has 25 g of carbs and a GU Energy Gel has about 22 g. Some gels are larger. To find your interval, divide 60 by the number of gels you need per hour.
Carbs in your drink count toward your hourly target. A typical 6% sports drink has about 30 g of carbs per 500 ml. If you take 150 to 250 ml at most aid stations, that can add 10 to 15 g of carbs each time and replace a gel every hour or so.
Check the race website for the on-course drink and where the aid stations are, then try that drink on long runs. If it upsets your stomach, carry your own gels and take only water.
3:00 runner, gels only
20, 40, 60, 80, 100, 120, 140, 160
Total carbs200 g (about 67 g per hour)
3:45 runner, gels only
20, 45, 70, 95, 120, 145, 170, 195
Total carbs200 g (about 53 g per hour)
4:00 runner, gels + drink
Gels at 20, 50, 80, 110, 140, 170, 200, plus 150 ml drink at 4 stations
Total carbsAbout 210 g (about 52 g per hour)
5:00 runner, gels only
20, 50, 75, 105, 130, 160, 185, 215, 240, 270
Total carbs250 g (50 g per hour)
| Plan | Gel timing (minutes) | Total carbs |
|---|---|---|
| 3:00 runner, gels only | 20, 40, 60, 80, 100, 120, 140, 160 | 200 g (about 67 g per hour) |
| 3:45 runner, gels only | 20, 45, 70, 95, 120, 145, 170, 195 | 200 g (about 53 g per hour) |
| 4:00 runner, gels + drink | Gels at 20, 50, 80, 110, 140, 170, 200, plus 150 ml drink at 4 stations | About 210 g (about 52 g per hour) |
| 5:00 runner, gels only | 20, 50, 75, 105, 130, 160, 185, 215, 240, 270 | 250 g (50 g per hour) |
Start fueling before you need it. If you wait for hunger or tiredness, you are already late.
Gut problems are common in marathon runners, and the gut adapts with practice. Use your long runs as rehearsals.
Gels work better with water. Take a few sips with each one. Drink to thirst, often 400 to 800 ml per hour depending on heat and your size. Do not drink more than you sweat: gaining weight during a marathon is a warning sign for low blood sodium, which is dangerous. If you are a heavy or salty sweater, a sweat rate test and some extra sodium can help.
Most runners need 6 to 10 gels. With 25 g gels, that is about 6 to 7 for a 2:30 finish, 8 to 10 for 4:00, and 10 to 12 for 5:30 to 6:00.
Most runners do well at 45 to 70 g per hour. Guidelines allow up to about 90 g per hour for races over 2.5 hours if your gut is trained.
Yes. Too many too fast can cause nausea, bloating, and diarrhea. Build up in training and keep doses small and steady.
Yes, if it is part of your schedule, but it should not be your first. Most plans start at about 20 minutes and repeat every 20 to 25 minutes.
Maybe fewer. Sports drink carbs count, so if you tolerate the on-course drink you can replace some gels. Practice with it first.
Use long runs as rehearsals: same timing, same products, same amounts, and some miles at marathon pace.
General guidance for healthy adults, not medical advice. Talk to a doctor or registered dietitian if you have a health condition, take medicines or have special dietary needs.
Use the free Mavr marathon fuel calculator to get gel timing for your pace.
Ask Kai, the coach in the app