ZoneSteady

ZoneSteady turns your Apple Watch into a powerful heart rate zone training tool — completely free, no subscription required. * Apple Watch is required. Start a workout on your Apple Watch and instantly see your real-time heart rate mirrored on your iPhone with a color-coded zone display. Whether you're warming up in Zone 1 or pushing your limits in Zone 5, ZoneSteady makes it effortless to train at the right intensity. REAL-TIME HEART RATE ZONES • Live heart rate streaming from Apple Watch to iPhone • 5 color-coded training zones calculated using the Karvonen formula • Full-screen zone display with bold, glanceable design • Signal detection alerts you when heart rate data is lost CUSTOMIZABLE ZONES • Personalize your zone boundaries with Manual Override • Adjust individual zone BPM thresholds to match your training plan • Cascading logic ensures zones never overlap or leave gaps • Percentages update in real-time as you fine-tune each zone • Custom zones sync automatically to your Apple Watch • Reset to scientifically-calculated defaults anytime 17 WORKOUT TYPES • Running, cycling, swimming, hiking, strength training, HIIT, yoga, rowing, and more • Start from your Watch or your iPhone — your choice WORKOUT HISTORY • Every session saved automatically with duration, calories, distance, and zone breakdown • Visual zone timeline shows how your effort shifted throughout each workout • Share workout summary cards with friends and training partners BUILT FOR APPLE WATCH • Native watchOS companion app with real-time zone display • Works with Apple HealthKit for accurate, sensor-level heart rate data • Landscape and portrait support on iPhone 100% FREE • No subscription. No paywall. No trials. • Professional-grade training tools available to everyone. REQUIREMENTS • Apple Watch Series 3 or later with watchOS 10+ • iPhone with iOS 17+ • Apple Health app with heart rate permissions enabled