Wrist heart rate monitor WHR inaccurate

Not resolved. OHR is useless for activities.

Like the others who replied, my issues with wOHR have not resolved. With activity, the wOHR is too low and unresponsive. 

I have also had some issues with it even at rest. I had heart surgery, and my resting heart rate is still very high. The wOHR fairly frequently shows values I don't quite trust, so I resort to checking pulse manually, or more recently checking against the Kardia ecg device. The 945 is indeed generally wrong when I have the feeling I don't trust it.

I will say that most of the time, the resting reading from the 945 is acceptable, and compares closely to the Kardia. I do find it useful in that regard, but I now have a feeling for when to double-check it. 

When the resting readings are wrong, I take the watch off for a few minutes. That seems to help as much as rebooting the watch.

Hm, not really. The WHR is wildly inconsistent. Sometimes it seems quite accurate and other it overestimates the rate by as much as 80%. One consistent thing is that if I tighten the wrist strap to almost-uncomfortable, it is more accurate, but even this fails sometimes. I haven't been able to isolate a single cause, but cold weather seems to worsen the overcounting problem.

Something worth mentioning: there are differend hardware revisions of the sensor around on FR945. At least I know of two different:

I originally had a Rev.B watch which got replaced by Garmin to a Rev.D watch. The LED color on the sensor changed slightly, the B green was definetely a lower wavelength (towards blue) while the Rev.D has LEDs which are slightly more into yellowish.

I mean it is still green and unless you place both watches next to each other, you probably won't notice much of a difference, but it proves that the sensor hardware got updated also.

I cannot make any guess which version is better or if any is better at all, but it is something to consider just in case there was an improvement to accurracy with the later hardware revision

I haven't had any problems for awhile now. I think a lot of the discrepancies have been resolved through updates. Also I saw a difference if you keep the heart rate continuous, and not checking every minute of so.  

After wearing the watch since September or so, I can surely say the OHR is not accurate.
When i sit still at work for hours it occasionally has peaks that obviously has nothing related to reality.
Also during runs it can be off for long and then change it offset without any reason.

In general I find it very unreliable, all the SW updates didn't help at all.

A 10km walk yesterday. Constant pace, super flat. HR expected to be constant after a short ramp-up. My expectation would be around 85-90 but I couldn't check while walking and didn't have my HRM-Run with me. In any case the results are nothing short of poor:

• 65-75bpm seemed too low (first 2.5 km)
• Readings are completely off between 2.5km and 7km.
• Last 3km back to the 65-75bpm range.

After completeing the walk (red frame) at the entrance to my building, I couch potatoed, but my OHR read even higher than the last part of the walk (80-85) for at least another 40 minutes before it finally agreed to return to a plausible 55-60:

Jeff B said:

Also I saw a difference if you keep the heart rate continuous,

What does that mean?

Jeff B said:

and not checking every minute of so

Clear to me how that would help in not noticing bogus values ;) 

I do still not trust the 945 OHR values. After more than a year, I am not complaining any longer and accept the actual status. For all activities, I use a chest strap, so that all the resulting metrics (TE, VO2_max, Lactate,…) get the correct input HR.

OHR metrics like Resting HR, stress and body battery seems plausible to me (at the level of hours and not at minutes). With respiration rate, I have my doubts, because it is not correct if make 5min at a level of 5 breaths per min.

The perfect 24h HR/HRV sensor still needs to be invented!