Sense Heart Rate Problem Fixed

[SurreyUser]

My new Sense was showing heart rate of 80 when self read pulse was 50, and my old Charge3 was showing 48. Also ECG was inconclusive, and sleep pattern not broken down by sleep stage. Occasionally Sense showed accurate reading, but mostly way over. This variance has been consistent since I got it 2 days ago.

The fix: I loosened my strap so that I could easily insert my forefinger under it at the bottom of my arm. Previously I had it pretty tight. Now reading looks normal. ECG works (after exercising to get my heart rate above 50). Have not slept yet, so don't know whether it fixes sleep stages too, but sharing this finding in case others find it helpful. 

[Guy_]

Hi @SurreyUser - while wearing it differently are recommendations, in the long term it probably makes no difference. Personally mine reads nearly twice what it should during exercise no matter how it is worn and others complain it under reads.

The good news is it is pretty accurate at rest and for sleep, if you aren't restless.

[SurreyUser]

Hello Guy, I've been meaning to update my entry, which was made shortly after purchase... I am sorry to say that for me the device is not performing on some key fronts:

- Heart rate: over reads. Typically 80, when it should in my case be less than 50 when I am at my desk working - and as you say resting heart rate seems fine. Is it confused by motion? It seems to be correct when attempting ECG as the hand is then resting on a table. 

- ECG: fails for me saying that it cannot operate when my heart rate is less than 50 - so no benefit there (and it then gives a correct heart rate!).

- Sleep: one reason for upgrading from Charge 3 to Sense was that the Charge 3 stopped recording sleep stages, having done so for the 2 years or so since purchase. Instead showing a dark blue line. My theory was that the device was old, but the Sense does not do it either. So either something has changed in their algorithms or my physiology has somehow changed!

For the rest, the Sense was recording steps OK and I like the text notifications - particularly handy for 2-factor authentication, which is fiddly if you have to wake up your phone to get them. I have stayed with FitBit because I wanted a long term data series on the things collected. I am also very happy for my data to be used by Google/Alphabet (as I think it is) to develop health monitoring etc.

But reluctantly I have concluded that the Sense is not delivering on the key things I wanted it for, and I intend to send it back and revert to my old  Charge 3.

[Guy_]

@SurreyUser- yes it does seem confused by motion.

Interesting the ECG doesn't work below 50, and this might be an issue for sleep too, possibly.

As you are going back to the Charge 3, have you tried restarting it recently, it may help.

There are regular updates to the app and maybe one of those messed up something, in any case it would be a good idea to restart the phone and see how it goes with the Charge 3 which might not be at fault. See if things change with the next Fitbit App update in case it is fixed.

[t.parker]

@Guy_ ECG does work below 50bpm but the report is inconclusive:

All it means is that when HR goes below 50bpm the algorithm cannot detect Afib. I always get "inconclusive" (in this example my average HR was 42bpm but it's not my all-time lowest so there is no chance for me for anything else but "inconclusive").

@SurreyUser you seem to be mixing up two things. There are two independent sensors to track your HR. ECG uses electrodes on the side of the device and all-day HR uses green LEDs at the bottom. There is no connection between them. The ECG sensor runs only when you use the ECG app and PPG (green LEDs) do not contribute.