Train with any Bluetooth chest strap: live zones, Lock Screen Live Activity, audio and vibration alerts, structured workouts, history and TCX export.
Train in your heart rate zones using your Bluetooth chest strap — no smartwatch required.
Strap Zone connects directly to your heart rate monitor and shows real-time zone data on your iPhone. Perfect for zone 2 training, fat burning workouts, HIIT, or any heart rate-based training.
WHY CHEST STRAP + PHONE?
Chest straps provide reliable heart-rate data during workouts and are often more responsive than wrist-based monitors. Most zone training apps require an Apple Watch. Strap Zone doesn't. Just your phone and your strap.
FEATURES
Real-Time HR Zones (Z1–Z5)
See your current zone with bold, color-coded display:
Z1 Recovery | Z2 Endurance | Z3 Tempo | Z4 Threshold | Z5 VO2 Max
Zone 2 Training Made Simple
Stay in your target zone for aerobic base building, fat burning, and longevity training. Audio alerts keep you in the zone without looking at your screen.
Structured Workouts
Build custom interval workouts with target zones, repeat blocks, and timed segments. Perfect for HIIT, threshold training, or guided zone 2 sessions.
Time-in-Zone Tracking
See exactly how long you spent in each zone during and after your workout.
Workout History
Review past sessions with detailed zone breakdowns and heart rate data.
Optional Apple Health Export
Off by default. If you opt in, Strap Zone can write your completed workouts and the recorded data you select to Apple Health: heart rate, estimated active energy, distance and GPS route, when system permissions allow. Strap Zone never imports health data from other apps.
Optional GPS + TCX Export
Record route, distance, pace splits, and export a complete TCX file for platforms like Strava, Garmin Connect, and TrainingPeaks. GPS can be turned off anytime in Settings.
Large, Clear Display
Big BPM numbers easy to read during any workout — on the treadmill, bike, or gym floor.
WORKS WITH ANY BLE CHEST STRAP
- Polar H10, H9, OH1
- Garmin HRM-Pro, HRM-Dual, HRM-Run
- Wahoo TICKR, TICKR X, TICKR FIT
- COOSPO, Magene, Scosche, and any Bluetooth 4.0+ HR strap
SIMPLE BY DESIGN
Optional GPS when you want route export. No account. Just heart rate zones — done right.
Your heart rate and GPS route data stay on your device unless you explicitly enable an export. No account.
Works on iPhone, iPad (with Split Screen support), and Mac with Apple Silicon.
Terms of Service: https://strap-zone.vercel.app/terms.html
Works great. All you need to monitor your heart rate for free!
Stopped working
DougArcane
I had used the free version for a month or so and I liked it enough to buy it. It no longer connects to Bluetooth and thinks Bluetooth is not enabled, even though all my other Bluetooth devices work just fine. So now completely useless to me.PS tried all the usual, downloading again, rebooting iphone etc.
Developer Response
Hey, thanks for reporting the issue. Fix is already live. Sorry for the hassle.
Spoken workout updates and heart-rate strap connections are now better.
• Distance alerts now announce both completed distance and pace in kilometers or miles. Optional current heart-rate updates can play every 30 or 60 seconds.
• The app automatically reconnects to your last used heart-rate strap.
Version 3.20.8
The developer, Wojciech Zieba, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
Health & Fitness
Purchases
Location
Identifiers
Usage Data
Diagnostics
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
Seller
Wojciech Zieba
Size
72 MB
Category
Sports
Compatibility
Requires iOS 16.0 or later.
iPhone Requires iOS 16.0 or later.
iPad Requires iPadOS 16.0 or later.
Mac Requires macOS 13.0 or later and a Mac with Apple M1 chip or later.
Location
This app may use your location even when it isn’t open, which can decrease device battery life.