Frequently asked questions
How do I set my max heart rate?
Go to Settings and toggle "Manual Override" under Heart Rate Max. If you do not override it, the app estimates your HRmax from your age using the Tanaka formula (208 - 0.7 x age).
Why is my heart rate not showing during the workout?
Heart rate needs a connected source: a paired Apple Watch running the companion app, or any Bluetooth heart rate monitor such as a chest strap. Make sure you have granted Health and Bluetooth permissions, and that your monitor is selected in Settings.
Can I change the interval durations?
The 4x4 protocol uses fixed 4-minute intervals and 3-minute recoveries. You can adjust the warm-up and cool-down durations in Settings.
Where is my workout data stored?
Your workout data is saved on your device and to Apple Health. The app keeps your workout history locally on your device so you can review past sessions, and you can delete any workout from the History screen. The app has no server and no analytics, you do not need an account, and it does not transmit your data off your device. Anything you share with another service is your choice.
The app crashed or something is not working.
Email us with a description of what happened. Include your iPhone model and iOS version if you can.
Contact
For bug reports, feature requests, or questions, email alicedevwin@icloud.com.