Norwegian 4x4 Heart Rate
VO2max interval timer with HR
About
This app guides you through the Norwegian 4x4 VO2max interval training protocol using your Bluetooth heart rate monitor. It provides real-time audio cues to keep you in your target heart rate zones during work and rest intervals.
What's New in Norwegian 4x4 Heart Rate
1.1
May 22, 2026
Added Live Activities on lock screen
FAQ
What is the Norwegian 4x4 Heart Rate app?
Norwegian 4x4 Heart Rate is a free app designed to guide users through the Helgerud VO2max interval protocol. It uses a connected Bluetooth heart rate monitor to provide real-time feedback and audio cues.
What heart rate monitors are compatible with Norwegian 4x4 Heart Rate?
The app supports any Bluetooth heart rate monitor that exposes the standard heart-rate service. This includes popular brands like Whoop, Polar H10, Wahoo TICKR, and Garmin HRM.
How does Norwegian 4x4 Heart Rate guide my workout?
The app guides you through a 5-minute warm-up, four 4-minute hard intervals with 3-minute easy intervals, and a 5-minute cool-down. It provides live audio cues to speed up or slow down to stay within target heart rate zones.
Does Norwegian 4x4 Heart Rate collect my data?
No, all your workout data stays on your phone. The app does not require accounts, collect analytics, or use servers, ensuring your privacy.
What is the target heart rate zone for Norwegian 4x4 Heart Rate?
During the hard work intervals, the target zone is 85–95% of your HRmax. During the easy rest intervals, the target zone is 60–70% of your HRmax.
How often is Norwegian 4x4 Heart Rate updated?
The latest version, 1.1, was released on May 22, 2026, indicating recent development activity. The app was initially released on May 21, 2026.
What devices does Norwegian 4x4 Heart Rate support?
Norwegian 4x4 Heart Rate is currently supported on iPhones. It has an age rating of 4+.
Does Norwegian 4x4 Heart Rate have ads?
No, Norwegian 4x4 Heart Rate is ad-free. It is a completely free application with no advertisements.