Correction, not encouragement
Most apps tell you the run was great. Rupl tells you when to ease off — during the session, by heart rate, before the damage is done. Praise is cheap; a timely «walk now» is not.
A running coach that lives on your watch.
It builds the week, guides you through it by voice, and corrects your effort by heart rate while you run. No account, no network, no subscription, no price.
Heart rate, not pace
Pace lies on hills, in heat and in traffic. Heart rate does not. Every limit in Rupl is measured on the pulse your watch already reads, which is why the app needs no thermometer, no phone and no server to know you are working too hard.
A regulator, not a plan
There is no twelve-week schedule to fall off. A repeating weekly shape, slow growth, and a rebuild from what you actually did after every illness, trip or missed fortnight. Miss two weeks and the plan meets you where you are.
One rule above all the others
No day exceeds your own thirty-day maximum by more than ten percent. In a cohort of 5 205 runners over 588 071 sessions, exceeding by 10–30% carried an injury hazard ratio of 1.64, and over 100% carried 2.28. It is the best-evidenced and least-implemented rule in the category.
Rupl itself sends nothing anywhere
No account to create, no server to trust, no analytics. Workouts are saved to Health; your plan and log are kept on the watch. This is not a promise about our intentions — the app makes no network calls at all.
Free
No price, no subscription, no trial. The project costs its author 99 dollars a year and nothing else, and that is the whole business model.
Status
In development. The training model is specified and verified in simulation; the watch app is being built. There is nothing to download yet.