What this result means
Fueling plans need calories burned, carbohydrate grams per hour, how many gels that implies, and whether caffeine fits your mass. This board runs those estimates together.
Calories use the ACSM running VO₂ equation from pace and distance. Carbs follow ISSN/ACSM-style grams-per-hour bands by race duration. Gels divide total carbs by your packet size.
Everything here is an estimate for planning — not medical advice, not a personalised nutrition prescription.
70 kg, marathon pace 5:00/km over 42.2 km → roughly 2,800–3,000 kcal and ~60–90 g carbs/hour depending on finish time. At 22 g per gel, that might be 8–12 gels spread across the race — check the board output for your inputs.
Shorter races show lower hourly carb needs; the same pace over 10 km burns fewer total calories than a marathon.
Calculation method
Calories: ACSM VO₂ (running) from speed and mass, integrated over distance. Carbs/hour: duration-based ISSN/ACSM-style ranges. Gels: total carbs ÷ grams per gel. Caffeine: 3–6 mg/kg ISSN range.
See /methodology for formula references and limits.
Does not know gut training, product labels, or medical conditions. Verify gel carb counts on the packet.
Heat, hills, and drafting are not in the calorie model.
Frequently asked questions
How are running calories estimated?
From ACSM VO₂ for running using your pace, distance, and body mass. It is an estimate, not a lab measurement.
How many gels do I need?
The board totals carbohydrate grams for the race duration, then divides by your entered grams per gel. Round up in real life if your gut tolerates it.
What caffeine dose does the board show?
ISSN-style 3–6 mg/kg body mass with a typical 30–60 minute pre-race window. Confirm with a clinician if you have heart or caffeine sensitivity concerns.
Is this medical advice?
No. It is deterministic arithmetic on published sports-nutrition references. Race-day choices need your experience and professional guidance when required.