Marathon Nutrition Timing (Gel Schedule)

Marathon nutrition timing guide. Build a simple gel schedule (when to take each gel) based on your finish time and carb target.

Even a great gel total can fail if timing is chaotic. A simple, repeatable schedule keeps energy stable through the final hour.

Start-early timing strategy
Spacing you can remember
Pairs with aid stations and water

How to time gels in a marathon

Create a simple schedule so you take carbs consistently and avoid late-race bonks.

Pick first gel time: Many runners take the first gel around 20-30 minutes.
Set an interval: Take a gel every ~25-35 minutes depending on target carbs/hour.
Pair with water: Take gels with water at aid stations when possible.

Fueling reference

Race-day carb targets and gel counts by finish time (baseline, no body weight entered)
Race	Finish time	Carbs/hour	Total carbs	Calories	Gels
Half marathon	1:20	45 g/hr	60 g	240 kcal	2
Half marathon	1:35	45 g/hr	71 g	284 kcal	3
Half marathon	1:50	45 g/hr	83 g	332 kcal	3
Half marathon	2:05	45 g/hr	94 g	376 kcal	4
Half marathon	2:20	45 g/hr	105 g	420 kcal	4
Marathon	2:50	75 g/hr	213 g	852 kcal	5
Marathon	3:15	75 g/hr	244 g	976 kcal	5
Marathon	3:45	75 g/hr	281 g	1124 kcal	6
Marathon	4:15	75 g/hr	319 g	1276 kcal	7
Marathon	4:45	75 g/hr	356 g	1424 kcal	7
Marathon	5:15	75 g/hr	394 g	1576 kcal	7

Other TrainPace tools

For AI agents

Every page on this site has a Markdown mirror at the same path with a .md suffix (for example /calculator.md), and honors an Accept: text/markdown request header on the HTML URL. The calculations here are also available as callable tools through a free public MCP server — no account or API key.