Marathon Fueling Planner
Gel-by-gel race plan from your expected finish time — when to take what, written like a pace band.
Start fueling at 20–30 minutes, long before you feel the need — by the time you're hungry the deficit is already running. Take gels with water (not sports drink — that stacks concentrations and upsets stomachs). Every item on this plan must be rehearsed on long runs; race day is an exam, not a lab.
Formula
For general information only — not medical or training advice. Estimates vary between individuals; consult a qualified professional before changing your exercise or nutrition routine.
Gel-by-gel race plan from your expected finish time — when to take what, written like a pace band. The Marathon Fueling Planner is a free, private marathon fueling tool — every result computes instantly in your browser with no sign-up and no data upload.
About Marathon Fueling Planner
Start fueling at 20–30 minutes, long before you feel the need — by the time you're hungry the deficit is already running. It applies total = g/h × finish hours; interval = race minutes ÷ gels. Use the Marathon Fueling Planner to get an instant, clearly-explained result with the working shown step by step — free, private and with the source method cited.
How to use Marathon Fueling Planner
- 1Enter your details in the Marathon Fueling Planner input fields above.
- 2The result updates instantly with the working and reference bands shown.
- 3Adjust any value to explore how it changes the outcome — it's free and unlimited.
Why use Marathon Fueling Planner?
- ✓Instant marathon fueling result that recomputes as you type — no waiting, no page reloads
- ✓100% client-side: your health data never leaves your browser
- ✓Shows the actual formula and your numbers substituted in, so you can see exactly how the result is reached
- ✓Based on published, citable sources (Jeukendrup AE, Sports Med 2014)
- ✓Free forever with no sign-up, account or app install
Frequently asked questions
How does the Marathon Fueling Planner work?+
Start fueling at 20–30 minutes, long before you feel the need — by the time you're hungry the deficit is already running. The calculation uses the formula: total = g/h × finish hours; interval = race minutes ÷ gels. Everything runs instantly in your browser as you type — your inputs are never uploaded.
Is the Marathon Fueling Planner accurate, and what is it based on?+
The method is traceable to authoritative sources, including Jeukendrup AE, Sports Med 2014; Burke LM et al., J Sports Sci 2011. Results are estimates — individual variation always applies, so treat the output as a well-grounded starting point.
Is the Marathon Fueling Planner free and private?+
Yes. It's completely free with no sign-up, and all computation happens locally in your browser, so none of your health data ever leaves your device.
Can I use this for medical decisions?+
This tool is for general fitness information only, not medical or training advice. Consult a professional before changing your routine.
What can I use the Marathon Fueling Planner for?+
It's commonly used for marathon fueling, marathon gels, race nutrition plan. Gel-by-gel race plan from your expected finish time — when to take what, written like a pace band.
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