3 ms·

For me, doing hill sprints on a bicycle sometimes completely fails to register on the Fitbit. My heart rate will sometimes show up in the 90-100 range on the Fi

For me, doing hill sprints on a bicycle sometimes completely fails to register on the Fitbit. My heart rate will sometimes show up in the 90-100 range on the Fitbit, despite my Garmin (which gets data from a chest strap monitor) showing me 160-170, which is far more believable. And then there are weird situations while merely walking around where I'll see strange spikes (160+) on the Fitbit when I know my heart rate is near 90 or so.

thr0w__4w4y 8y ago
I've seen the same thing. I'm a middle aged guy, endurance athlete, was competitive nationally at the NCAA level way-back-when. I learned a lot about nutrition and physiology as part of my sport. Back then the conventional wisdom (not universally accepted) was that max heart rate was "220 minus age". Well, if you do that math on me, the peak -- not sustained -- rate that I reach now is outrageous, in a good way. Granted, I've learned to push through and perform at high levels of exertion and exhaustion, it didn't happen from one day to the next. Anyway, there were times ~3 years ago where I'd be tearing up a workout, Fitbit would read 130, I knew it was f*Ing wrong. Bought a chest strap and saw what was really going on. Low 190s. Thanks FitBit!! I would have been happier if the FitBit just put up "??? WHAT THE HELL ARE YOU DOING OLD MAN???"