Comparing Data: Whoop vs. Garmin Fenix 2

This morning was my second workout with a Whoop on my wrist. In both cases, Whoop’s data is inaccurate and grossly overstates the intensity of the workouts. I recorded both sessions with the Whoop and a Garmin Fenix 2 with an HRM-Run chest strap.

The workout was a recovery session with an average heart rate of less than 60% of maximum. Despite being crazy-easy, the errors in the Whoop data (and the lack of any customization options for heart rate zones or thresholds) had this workout classified as “more strenuous than 96% of all days across Whoop athletes.” If only that were true…

I have unusually high heart rates at all intensities. This isn’t due to fitness or intensity, but stroke volume. It has to do with the size of the heart relative to body size. My heart is probably relatively smaller than average, so it beats faster to keep up.

So without the option to correct for this, the Whoop software thinks I’m working harder than I am. It seems like an amateurish oversight on their part. In contrast, any other heart rate system I’ve used always allows the user to set personalized heart rate zones or, better yet, an anaerobic threshold.

I was tempted to try Whoop because they recently changed their revenue model from exorbitant to merely over-priced. If this continues, I’m hoping that their return policy is as good as their marketing and graphic design.