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Erratic Wrist based Heart rate : BUG + Root cause

stevendessein
over 1 year ago

Hi,

already raised in other Posts (see list at the end)
and tried all of this:
The Heart Rate Sensor on My Garmin Watch Is Not Accurate

Problem is not accuracy, the heart rate is sometimes completely wrong.

I went back into all activities (Garmin connect shows the watch + firmware used in each activity) and came to this conclusion:

firmware 10.x   11.x     :      ok      (not as accurate as chest wrap but ok)

firmware 12.x + later   :      not ok   (unexplainable values going too low / too high)   

it's not the temperature (cold) ; it's not the cadence lock ; it's not the position/tightening  : ruled that out and did many tests.

If you can confirm your findings (look in history + which firmware) then we can raise this as a firmware bug to be solved

https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-255-series/315431/low-hr-readings-during-running-activity/1568731#1568731

https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-255-series/322884/can-i-trust-you-garmin-255/1569764#1569764

https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-255-series/323535/heartbeat-abnormality/1569583#1569583

https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-255-series/322025/heartrate-data-totally-wrong-when-walking

https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-255-series/309071/heart-rate-about-20-bpm-higher-since-new-firmware

  • 0 over 1 year ago

    Hi,

    I think this is fixed now with the latest update. I'm running on 15.19 now.

    I had the problem that in my strength and martial arts sessions the heart rate did not seem to be real.

    Here are screenshots of two similar sessions before and after the update.

    this is a screenshot before the update.

    .

    this is one after

  • 0 over 1 year ago in reply to 5872338

    Lucky you. I was hoping that with the new release the problem I have could be  fixed but  is not like that.  I  still report abnormal BPM increase  when walking  (simply walking  without or  with an activity) . Totally unreliable heart rate monitoring, increasing abnormally the intensity minutes per  week , that became totally  useless. 

  • 0 over 1 year ago in reply to Bruno056


    Hi,
    what helped for me:
    - wear the watch ABOVE the wrist bone (like it would be worn as a second watch ...). Snug, but comfortable: the watch should not shift while running
    - before starting workout: go to the sport (eg running) then switch to a display showing the heart rate, for some unknown reason it often shows wrong HR (too high) for me, after +/- 20 seconds: it's correct; only then start the workout (hit the start); during the wait time It will also have found the GPS

  • 0 over 1 year ago in reply to Garmin-Sierra

    1. Yes

    2. yes

    3. Yes

    4. Uk

    This has been happening me since a firmware update, really disappointing regularly during runs my heart rate drops by a huge amount and stays down until the end of the run. Attached photo shows a typical one you can see my heart rate was at 150ish at the start, this was a hard tempo session, really not acceptable 

  • 0 over 1 year ago in reply to Michael Stuart

    And again today... This really needs fixed

  • 0 over 1 year ago in reply to Garmin-Sierra

    Yes 

    Yes

    Yes

    Spain

    Here there two graphs of the same run (03/09/23) with Vivoactive 3 + Garmin Band HRV-Dual (top) and FR255 ( bottom). It is clear that the FR255 measures are way below the values from the band until almost the end.

  • 0 over 1 year ago in reply to zikandas

    What was the cadence during the run?

  • 0 over 1 year ago in reply to zikandas

    Top Vivoactive 3 + band, bottom FR255.

    For some reason the graphs provided by Garmin Connect have different zoom but I would say the readings with both watches are very similar.

  • 0 over 1 year ago in reply to zikandas

    I was just wondering if the heart rate sensor could have locked onto the cadence, but the cadence is higher than logged heart rate. Your real heart rate is however very close to your cadence, and I guess the algorithm has some filtering to avoid cadence lock. That could be why it struggles to pick up correct heart rate.