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This tells you what. The full plan tells you when.
Get a session-by-session nutrition plan with exact product quantities, GI protocols, and pre-race timing — built for your specific race.
The cheat sheet gives you hourly targets you can stick to from the start line to the finish, plus a pre-race breakfast number, the timing of your first in-race fuel, and a caffeine plan tuned to your habitual intake.
For a 70 kg runner targeting a 4-hour marathon in moderate weather (15–25 °C), with average gut sensitivity and daily caffeine use, the cheat sheet returns roughly:
| Target | Number |
|---|---|
| Carbs / hour | ~50 g (range 43–68 g) |
| Fluid / hour | 500–800 ml |
| Sodium / hour | ~450 mg |
| Pre-race breakfast | ~140 g of carbs, 2–4 h before the gun |
| First in-race fuel | ~30 min, then every 30 min |
| Caffeine | ~56 mg/hr after the first 60 minutes |
Half marathon, ultra, 70.3, and 140.6 athletes get different numbers — run the calculator above for your specific race.
Carb targets follow Asker Jeukendrup's carbohydrate oxidation research. A trained athlete can absorb up to ~60 g/hr of glucose alone, and up to ~90 g/hr when glucose is combined 2:1 with fructose (multi-transportable carbohydrates), because the two sugars use different intestinal transporters and don't compete. We bias targets down for athletes who flag high gut sensitivity, and shift them slightly lower in the heat where blood flow to the gut drops.
Fluid targets follow the ACSM exercise-fluid position stand: replacing 70–85% of sweat losses, scaled by body mass and ambient temperature. Sodium ranges (300–800 mg/hr depending on duration and heat) are based on observed sweat sodium losses across endurance athletes. Caffeine guidance follows IOC consensus: 3–6 mg/kg total dose, split across the race, only for habitual caffeine users.