Just Zones: Heart Rate Zone 2
Weekly cardio minutes & trends
About
Analyze your heart rate zones from workouts recorded in Apple Health. Visualize weekly trends, detailed workout breakdowns, and effort/recovery phases. Customize zone models or use estimates, with all data processed on your device for privacy.
What's New in Just Zones
1.3.1
November 4, 2026
Fixes a rare crash on the route screen.
Subscriptions & In-App Purchases
$9.99
Just Zones Pro
Full history and trends. One-time purchase.
Developer apps
FAQ
What is Just Zones?
Just Zones analyzes your heart rate zone data from workouts logged in Apple Health. It provides weekly summaries, detailed workout breakdowns, and insights into effort and recovery phases, all processed on your device.
Does Just Zones record workouts?
No, Just Zones does not record its own workouts. It reads data from Apple Health, which can be generated by the Apple Watch, the Workout app, or other compatible apps.
How does Just Zones calculate heart rate zones?
Just Zones uses Apple's recorded zones when available. If not, it provides a heart-rate-reserve (Karvonen) estimate, with the BPM bounds and inputs always visible. You can also manually set your max heart rate, resting heart rate, and LTHR.
Is my health data safe with Just Zones?
Yes, Just Zones prioritizes privacy. It reads data from Apple Health read-only, never writes back, and processes all health data on your device. The app has no accounts or backend, and anonymous crash reports do not include health data.
What are the 'Trends (Pro)' features in Just Zones?
The free version shows 30 days of trends for weekly intensity mix and training times. Just Zones Pro, a one-time purchase, extends these trends to your full history and includes Family Sharing.
What devices is Just Zones compatible with?
Just Zones requires an iPhone with workout and heart-rate data in Apple Health. It does not have an Apple Watch app.
How often is Just Zones updated?
The latest version is 1.3.1, released on November 4, 2026. The app was last updated on November 4, 2026, indicating regular updates.
What is the age rating for Just Zones?
Just Zones has an age rating of 4+, making it suitable for users of all ages who meet the device requirements.
