When comparing with Versa 1 and other devices which all indicate the same heart rate during exercise, the Versa 4 seems to show wildly fluctuating results, sometimes worse than the Sense, known to be inaccurate during exercise.
At one point it showed between 50 - 60 beats per minute difference from the reference values which was slightly worse than a Sense.
RHR on the other hand seems to be only a few beats higher than the reference Versa 1
Moderator Edit: Clarified subject
