Heart rate not accurate while using stationary bike with Inspire 3

[JDJL]

I just did my first cardio session with my new Inspire 3. The device was showing an increase in heart rate, as expected. Until it got to 129 BPM as I was ramping up my session. It stayed there for less than a minute and then drop down to between 75 and 95, while I was at full speed on a stationary bike for 10 minutes (that heart rate is what I get at a brisk walk). The bike's monitor showed 145 to 160 BPM which is certainly closer to reality then what the Fitbit showed.

I tried switching the wrist my Fitbit was on, and wipe down the sensors with a dry towel, with no change in the reading. I don't see any other posts here about such issues.

Is there anything I need to do with this device to reset it or something before my next cardio session to determine if it's defective or some other issue.

Moderator Edit: Clarified subject

[Baltoscott · Accepted solution]

@JDJL — I don’t think it is defective, but you can try resetting your Inspire in settings on the device (settings is the gear icon you see after swiping down several times on the watch face).

In general, however, wrist-based trackers struggle when you flex your wrist and forearm muscles. That is a particular problem with bike riding, especially when you are pushing hard and gripping hard. This is less of an issue for walking/hiking/running. Also, in my experience HR reading changes also seem to be somewhat delayed from actual, but when looking at the exercise record after the fact, the amount of time you are in HR zones (peak, cardio, fat burn) makes sense; also, high HR may not be ‘there’ long enough to display on the tracker, but do show up in the exercise record, though I would not be surprised if were still different than your exercise bike’s palm monitors.