Zonelock

Train with purpose. ZoneLock gives you real-time heart rate zone tracking during every workout, so you always know if you're pushing hard enough — or too hard.

HOW IT WORKS
Pair any Bluetooth LE chest strap using the standard heart rate profile — including Polar H9, Polar H10, Wahoo TICKR, and Garmin HRM-Pro. ZoneLock reads your live heart rate and gives instant audio and visual alerts the moment you drift above or below your target zone, so you can adjust without breaking focus or checking your phone constantly.

PERSONALIZED ZONES
Calculate your training zones your way: quick age-based estimate, manual max heart rate entry, or a guided submax test for a more precise result. ZoneLock reminds you to recheck your resting heart rate every few months and your max heart rate yearly, so your zones stay accurate as your fitness changes.

SESSION HISTORY (Pro)
Every session is saved automatically. Review your history, see how much time you spent in zone, and track trends over time with ZoneLock Pro.

ZONELOCK PRO
Unlock unlimited session history and trend tracking for $2.99/month or $19.99/year, with a 7-day free trial. Cancel anytime in Google Play.

WORTH KNOWING
ZoneLock reads your heart rate in real time over Bluetooth, so the app needs to stay open and your chest strap connected during a session to keep working. ZoneLock is a training tool, not a medical device, it doesn't diagnose or manage any health condition.