Fueling practice guide

Fueling is a skill

Fitness is only half the marathon. Execution is the other half.

If you under-fuel, you don’t just “feel bad” — you slow down, your form collapses, and cramps/GI problems become more likely.

The simplest plan that works

1. Pick a starting carb target you can tolerate.
2. Turn it into a schedule (every 15–30 minutes).
3. Practice it on long runs until it’s automatic.

How to practice (without blowing up your gut)

• Practice at easy-to-steady effort first.
• Keep the same products for a few long runs before you change anything.
• If you get GI issues: reduce dose size, increase spacing, and simplify.

Hydration: avoid extremes

Drink enough to stay stable, but avoid over-drinking. Practice a plan in training and adjust for heat and sweat rate.

Next steps

• Marathon fueling planner
• 18-week marathon plan
• Taper week checklist