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Practical guide

Practise fueling before the longest sessions

Build an endurance fueling practice with measured intake, tolerance notes and clear changes before race day.

Updated Oct 17, 2026

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Turn a fueling target into a rehearsal

A fueling-practice guide should connect a population range to food, drink, timing, intensity, and course logistics you can actually repeat. Begin with familiar products and record carbohydrate, fluid, sodium, and caffeine separately. “Two gels” is not precise when serving sizes differ.

Use a one-variable test

VariableWhat to record
Productbrand, flavor, serving, and label
Timingintake time and training point
Concentrationpowder, water, and bottle size
Contextbreakfast, intensity, heat, and sleep
Responsehunger, thirst, nausea, bloating, urgency, and energy

Test the first version during an appropriate long session at controlled effort. Change one major variable before repeating. A plan that works on the bike may not transfer directly to running because posture, impact, and intensity change.

Repeat the test in conditions relevant to the event, but do not combine new heat, pace, products, and concentration in one session. A clean comparison is more useful than a dramatic rehearsal whose cause cannot be identified.

Map the current event

Confirm the organizer's live aid locations, products, bottle rules, litter zones, and special-needs access. Build a simple fallback for one missed item without automatically doubling the next intake. Use the marathon fueling planner, half-marathon breakfast practice, or IRONMAN transition-bag checklist to make the plan event-specific.

For a middle-distance triathlon, keep bike and run assumptions separate in the IRONMAN 70.3 fueling planner.

Safety boundary

Repeated vomiting, confusion, fainting, severe breathing difficulty, chest pain, or inability to keep fluid down requires appropriate support. More fluid is not automatically safer. This guide is educational and not medical advice or an individualized nutrition prescription.

Put this into action

Open the plan and tool that match this guide

Worksheet

Use this before you choose

Your race-day schedule

  • • Carb target (g/h): ____
  • • Dose interval (minutes): ____
  • • Carbs per gel/serving (g): ____
  • • Hydration target (ml/h) when cool vs hot: ____ / ____
  • • Plan B if GI issues happen: ____

Checklist

Check your choice

Fueling practice checklist

  • • I will practice fueling on long runs (not just on race week).
  • • I start fueling early (before hunger hits).
  • • I use a schedule (every ____ minutes), not vague intention.
  • • I keep products consistent while checking tolerance; one successful session does not guarantee race-day tolerance.
  • • If GI issues appear, I change one variable at a time.
  • • I also practice hydration in heat (not just carbs).
  • • I avoid trying new products in the final 2 weeks before race day.
  • • I have a plan B if I can’t stomach gels (drink mix / chews / simpler dose).

Adaptive AI coach for iPhone

Meet your adaptive AI coach.

Tell your coach what you are training for. It builds the plan, follows the work you complete, and adapts upcoming training when recovery, your schedule, or real life changes.

FAQs

When should I start practising race fueling?

Start early enough to repeat and revise the plan before peak sessions. Do not wait for the longest workout or race day.

Should I change several fueling variables together?

No. Change one product, amount, timing or concentration variable so the result is interpretable.

What if fueling causes severe stomach symptoms?

Stop or reduce the test and use appropriate medical or sports-dietitian support when symptoms are persistent, severe or concerning.

How many times should I practise race fueling?

Use several comparable sessions so one good or bad day does not decide the plan. Leave enough time to change one variable and repeat.

Should I count carbohydrate in sports drink?

Yes. Count carbohydrate from drinks, gels, chews, and food together while recording fluid separately.

What if a product causes stomach problems?

Review product, amount, concentration, timing, intensity, and pre-session food. Persistent or concerning symptoms need qualified assessment.

Should I double intake after missing a station?

Not automatically. Use a rehearsed fallback, consider the remaining course and symptoms, and avoid creating an unfamiliar large dose.

Your path

Perform on the day

The decision this page helps you make

Fueling becomes part of execution only after the products, timing, amounts, and carrying method have survived training practice.

Keep going

Sources