Weekly goal, not daily guilt
Can only manage 5 km on a day the plan wanted 17? endurancr banks what you ran toward the week and spreads the rest across your remaining easy runs, so the week still lands on target.
iPhone and Apple Watch
Training that adapts to the runs you actually do.
endurancr builds a personalized marathon plan, then reshapes it week by week from your recorded runs. Run on your iPhone or your Apple Watch. Everything stays on your device.
Free. No account. No ads. No cloud.
How it works
You set a goal once. endurancr does the rest, adjusting the plan as your fitness and your week change.
1
Set your goal
Pick your race and date. endurancr generates a full plan using the VDOT method from Jack Tupper Daniels, paced to your current fitness.
2
Run and record
Record on your iPhone with GPS, or on your Apple Watch to add heart rate. Every run is saved to Apple Health.
3
The plan adapts
endurancr reads your runs back from Health, re-paces future sessions, reschedules a missed long run, and eases the load when you are fatigued.
Built for real training weeks
Key sessions stay protected
When it rebalances a week, your long run and quality sessions keep their prescribed distance. Only easy runs flex, and never past a sensible cap.
iPhone or Apple Watch
Start a run on either. The Watch adds heart rate and a route. The plan you set on iPhone syncs to the Watch, which then works on its own.
Post-run feedback
Finish a run and see exactly where it leaves you: distance, pace, and how much of the week is done, with what remains.
Fatigue aware
endurancr watches resting heart rate and recent load, and softens the plan when the signs say you need it.
Everything in Apple Health
Runs are stored as standard workouts in Apple Health. Progress is read back from there, so your data is yours and lives where you expect it.
iPhone and Watch, together or apart
Together
Set your goal on the iPhone and it syncs to the Watch automatically over a direct, local connection. Run with whichever device you have. Because both read the same Apple Health data, a run on one shows up in your weekly progress on the other with nothing to sync by hand.
Apart
Left your phone at home? The Watch already holds your plan and records, saves, and summarizes the run on its own. Prefer to leave the Watch off? The iPhone does the whole job with GPS. Neither device needs a network, and neither needs the other to be useful.
Private by design
endurancr has no backend. There is nothing to log into and nothing sent anywhere.
- Runs entirely on your device, using Apple frameworks only
- No account, no login, no identity
- No cloud, no third-party services, no tracking
- Your plan and runs never leave your Apple devices and Apple Health
- Free forever, with no ads and no in-app purchases
Get endurancr
endurancr is distributed through Apple TestFlight. You will need an iPhone on iOS 26 or later, and the free TestFlight app.
Open TestFlight inviteReplace this link with your TestFlight public invite URL.