Anyone STILL having heart rate accuracy issues with their Fenix 6?

Hi all,

Super frustrated, but I am still having issues with my Fenix 6S and heart rate accuracy even with the 4.20 software update. I'm wondering if it's just me or what the deal is? I had a 5S Plus before this and had no issues doing the same activities so I really don't think it's user error. My heart rate hardly reads over 110 during really vigorous exercise when my heart rate is closer to 160+. I have tried wearing on the inside of my wrist, tried my other wrist with no luck. It consistently reads 80-110 bpm the whole time. I wouldn't have bothered to upgrade if I knew this was going to be an issue. I know that wearing a chest strap is the most accurate, but I don't like to have to wear it for all of my work outs and my old Fenix was totally fine as well as my apple watch before that. Any suggestions? 

  • Impossible to get higher than 154 when I use to get 178 as master HR... Problem start after updating to 6.1

  • It's starting to feel like there is something about the update process that is breaking functionality. Perhaps some files get corrupt or overwritten and shouldn't,  perhaps files are cleaned, and shouldnt, or the other way around. Too much stuff that is not changed per version released, keeps breaking for folks

  • It's starting to feel like there is something about the update process that is breaking functionality.

    I have exactly the same idea. Maybe a file will become corrupt

  • I did a master reset a few days ago. Then I switched off the watch and left 24 there. Then I turned on the watch. Suddenly the HR values were very good. I was happy. Until I noticed that my body battery remained a straight line. I have NEVER had any problems with body battery. Never. then I switched the watch off again for a long time. Body battery is currently working again, but HR is not coming up. It is to be crazy. Since we all report different behaviors, but the thing always occurs or disappears after an update. Or stay the same, I have exactly your thoughts.


  • I updated sw 6.1 yesterday and did run today. Pulse was ok as I used strap but hour and half after my training when sitting on sofa, watch started to alert too high rest pulse. I thought I was going to die but when I checked with Omron M3, pulse and everything is ok. So i'm wondering also, did something broke on 6.1 update? GC shows also some weird spike on pulse at the time when alert went on.

  • how did you do your last updates? windows / mac? webupdater? wifi? ..

  • Since i hate sleeping,  my body battery always dips lots.  I have frequently,  regardless of version (even back in 2.70) i have had a solid line on 5 body battery.  Though it makes sense of 0 not being realistic,  but what would 0 body battery mean... that you're so exhausted and bed resting is necessary? At any rate... often solid 5 lol

  • The body battery is working again. But HR back in the basement. lol

  • Hi Guys! After yesterday installing the official FW 6.10 on my f6x Sapphire, I did a stress test today.
    After having observed this problem on 2 watches and for about 5 months, it still hasn't improved for me. Both watches were ok with "out of the box" FW. The problems started after an FW update and still exist for me.

    About the test:

    I wear my fenix 24/7 with WHR. In addition, I put on my Polar OH1+ this morning and had it tracked. So my heart rate was tracked by 2 devices at the same time.
    fenix in allday tracking.

    I did some housework first. Then I also put on my chest belt to connect my trainer. The polar tracked itself and I later synchronized the values.

    So I have 3 HR references.

    Fenix ​​- WHR in 24/7 mode

    Polar OH1+ recording mode

    Cross trainer connected with HR belt.

    now it was getting exciting. can my fenix with the new FW 6.10 in 24/7 mode at least partially follow the HR values?

    NO!

    I almost died in this test.
    I spent almost 30 minutes in heart rates that were already going towards my HR max of 196.

    I dripped sweat and the fenix did not rise. Almost 30 minutes no increase. On the contrary, the Fenix ​​went down again.

    The fenix was always in a range between about 90 and 120. It couldn't go any higher, while I've been steady at 160 to 195 for a long time.

    after 30 minutes i started the activity profile "cardio" on the fenix.
    The Fenix ​​behaves as I expected. As soon as I had pressed the start button, the HR went up. And these values ​​were also exact (which also shows that I had put on the bracelet well and the sensor was not dirty.)

    here is the behavior of fenix after 30 minutes. at this moment I started the activity profile "Cardio".

    After I spent 30 minutes also monitored by 2 other devices in an HR area that went in the direction of HR max. 

    A short video :

    https://app.box.com/s/ieiwuiy9phrtgu9m2hfunzyrubgme8ew

    here the activity cardio, which I started after 30 minutes, shown in connect. You can see how real HR is reached in a very short time : 

    Conclusion :
    Nothing has changed for me.
    Garmin, I'm going to finish a zip file with my data and send it to you. Again!