About HAM.RUN

HAM.RUN is a free, browser-based suite of physiology-grounded models for marathon training and racing. Every calculation runs client-side; nothing about your training is uploaded unless you opt in to cloud sync. The models are derived from peer-reviewed exercise science (Banister fitness-fatigue, Riegel race prediction, Minetti gradient cost, Jeukendrup substrate oxidation, Gabbett ACWR, Scoon heat acclimation, and more) and are intended as educational exploration, not medical prescription.

The site covers running economy, marathon periodization, training adaptation, heart-rate pacing and cardiac drift, substrate and time-to-exhaustion modeling, caffeine pharmacokinetics, sauna heat acclimation, race-time prediction, and elevation profiles for 12 World Marathon Major and other notable courses.