Versa 2 Heartrate Sensing During Exercise

[DaveLeeNC]

When I ride my bike I have a Garmin HR strap (Ant+ connected to a Garmin computer device) and I have tons of experience with this setup and it is pretty solid and reliable. 

I recently acquired a Versa 2 and when I see the HR #'s on my FB Dashboard there is one other thing that is 100% reliable - the Versa 2 will show HR #'s dramatically lower than those on the Garmin. On a bike ride yesterday (90 minutes of continuous riding) the HR average on the Garmin was 137 and on the Versa was 109 (I do a lot of riding - this is totally wrong). At any instant in time that I look at the Versa vs. my Garmin they might roughly match (say within 5 bpm) but the much more common occurrence would be where the Garmin might read 142 and the Versa would read 107 (or blank). 

This apparent gross inaccuracy seems to be only during exercise (where this time of year I am sweating). My purpose in having the fitbit does not involve accurate HR during exercise #'s (I have that elsewhere). But what is going on here - is it a sweat issue?. This behavior seems pretty consistent to me and I don't see how I could get useful exercise statistics from this. 

Thanks.

dave

[Rich_Laue]

Your heart rate strap is reading the electrical signal from the brain. 

Fitbit is looking at the timing in the changes of blood density at the wrist. 

You may want to look at this doc @DaveLeeNC 

What factors can affect my heart-rate reading on my Fitbit device? 

[DaveLeeNC]

Thanks - I had seen that earlier. I assume that no one is saying that seeing an average HR of 109 over a 1+ hour exercise time and then seeing a average HR of 137 using a different device (same time period) is just how it works when you use those 2 different sensing technologies. 

dave

[DaveLeeNC]

FWIW, my problem seems to be the same as has been extensively discussed here. Versa 2 heart rate accuracy concern - Fitbit Community . 

dave