Avoid Hitting the Wall (Marathon Fuel Plan)

Avoid hitting the wall with a simple marathon fuel plan. Estimate carbs/hour, gels needed, and a timing schedule you can execute on race day.

The "wall" is usually a mix of going out too fast and running out of carbs. A steady pacing plan plus consistent carbs is your best defense.

Carb targets and gel plan
Simple schedule you can follow
Works with your goal finish time

How to reduce your risk of bonking

Create a pacing + fueling plan that keeps effort controlled and carbs consistent.

Choose a realistic goal: Pick a goal pace you can sustain without early surges.
Fuel consistently: Set a carbs/hour target and stick to a schedule.
Practice: Rehearse gels and pacing in long runs before race day.

Frequently asked questions

Is the wall only about fueling?

No. Pacing and conditioning matter a lot. But fueling is the most controllable lever on race day.

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

Method and sources

The numbers on this page are computed with the same code as the TrainPace calculators, from these published methods. They are training guidance, not medical advice.

Jeukendrup, A. (2014). A step towards personalized sports nutrition: carbohydrate intake during exercise. Sports Medicine 44(Suppl 1), S25–S33 — carbohydrate targets by event duration, and glucose + fructose for intakes above 60 g/hr.
Thomas, D.T., Erdman, K.A. & Burke, L.M. (2016). Nutrition and Athletic Performance (joint position statement of the ACSM, Academy of Nutrition and Dietetics, and Dietitians of Canada). Medicine & Science in Sports & Exercise 48(3), 543–568.

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