Adjusting the equivalence between speed and heart rate

If you enter your resting heart rate and your maximum heart rate in your profile and have calculated a MAS, we will tell you, for example, that you should run between 5:00 and 5:10/km (140-146 bpm).

It is possible that your heart rate (HR) will be higher or lower if you run at this pace.

We use the Karnoven formula to calculate this. 

If you have too much variation, there are several possible explanations:

• The accuracy of your heart rate sensor, as wrist sensors are generally unreliable. Read this blog article comparing different HR sensors.
• The altitude difference: If you run with a slight altitude difference, your heart rate will inevitably be higher.
• The weather: When it is very hot, your heart rate is generally higher than usual.
• If the HR range is too low, your HR max may be underestimated. If you use the formula 220 - age, it is an average value that may not apply to you.

If you notice discrepancies in endurance sessions (active or easy endurance), prioritize the heart rate target. In these sessions, pace is only an indication.

For interval or pace-specific sessions on road or track, prioritize the target pace.

If the gap between the suggested pace and your actual effort is too large, first check your heart rate measurement quality. A chest strap or armband is generally more reliable than an optical wrist sensor. If needed, redo a field test to refine your HR max.

If the mismatch remains significant, your MAS may be overestimated or your HR max underestimated. You can update these values in the app. Lowering the MAS slightly will lower the suggested paces and mechanically raise the target heart rate. Increasing HR max will also raise the target heart rate.

Don't just go by the numbers, but also by how you feel: for easy endurance, you should feel comfortable and able to stay in control. A few training sessions will help you find the right rhythm.

Have fun with your training!

Updated on: 18/07/2026