ZoneLock

Train smarter. Stay in your zone. ZoneLock is a heart rate zone training app built for athletes who train with intent. Connect your chest strap or Apple Watch, pick your zone, and get real-time alerts the moment you push too hard or need to work harder. ZoneSignal daily readiness Before every session, ZoneSignal reads your sleep, HRV, resting heart rate, and recent training load to tell you whether to go hard or ease off. No guessing. Just a clear daily signal backed by your own data. Personalised heart rate zones Set up your five training zones using the Karvonen method, refined by a guided submaximal fitness test. ZoneLock calculates your exact BPM ranges and remembers them so every session starts in seconds. Apple Watch and chest strap support Train with a Polar H9, H10, or any Bluetooth chest strap. Or use your Apple Watch as your live heart rate source. Sessions sync automatically even if your phone was closed during the workout. Session history Every session is saved with your time in zone, average BPM, max BPM, and a full breakdown of time spent below, in, and above your target zone. Built for serious training Zone 1 through Zone 5. Dark mode. Share your session summary. Designed to be readable at arm's length mid-workout. ZoneLock is free to download. Pro unlocks full session history, session stats and trends, and ZoneSignal readiness scoring.