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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 in reply to jerrymk

    I guess the sensor is picking up several frequencies at any given time, and the main challenge for the algorithm is to figure out which one is most likely the actual heart rate. There will typically be the cadence, the heart rate, and several harmonic variations of it. The algorithm knows what the cadence is, and will try to filter that out. It also know what it guessed as heart rate five seconds ago, and knows how fast heart rate can change. If it monitors what you are doing, it will be able to guess how likely a rapid change is. 

    A restart will probably remove the heart rate history from memory, and make it decide from scratch.

  • 0 over 1 year ago

    I'm having the exact same problem. Since the 12.x firmware the HR sensor is just off, whatever I do during the activity. It's not cold, or mispositioned watch on wrist... Garmin, pls fix it it's been too long!!

  • 0 over 1 year ago in reply to 6581770

    I left the HRM Pro at home on purpose today, and tested a challenging treadmill interval session with only wrist heart rate.
    It seems to be perfectly spot on except for a significant increase in heart rate after 20 minutes of walking at the start. Once I started running, it was very responsive.


  • 0 over 1 year ago in reply to ovekvam

    Could you help to test in outdoor running & floor climming acitivities? In my case most innormal HR from that activities.

  • 0 over 1 year ago in reply to dotuancd

    I will not be testing those anytime soon. I have deleted the floor climbing app from the watch, and I don't have any suitable stairs nearby. Outdoor running is on my plan, but I am waiting for the winter to end first. Besides, I will first use the HRM Pro to get it calibrated by GPS.

  • 0 over 1 year ago in reply to ovekvam

    Lucky you . Not in my case. By the way I guess that the problem of erratic data when walking is regarding a much larger customer base ,  since I  think that most of the people is not checking the HR when walking without an activity. And watching another of  your post I noticed that you also detected an abnormal sudden increase of HR when walking (indoor). For me , I repeat,  when running 255 is fine,  but  when walking is totally unreliable .  The replacement odf the HR sensor applied on the 255 is not a minor  change.

  • 0 over 1 year ago

    Will raise a support ticket referring to this post.

    also tried this:
    - power off - power on
    - factory reset (but it keeps same firmware)
    - cleaned sensor (with non alcoholic product) + assured optimal skin contact (yes : even used razor blade ...)
    >> doesn't help
    Today HIIT training warming up 30 min then 15 x 30 intervals
    warming up: goes to 150 (too high)  ; doesn't pick up the 15 x speed sessions ....


    same training done on 12/08/22  11.12 firmware:  HR ok (+/- 125 during warm up; picks up the right HR doing the 15 x high intense sessions)



    Same+ Chest-HR:


  • 0 over 1 year ago

    UPDATE:

    contacted Garmin Support and mentioned everything (referred to this topic ...)

    Until now, only got explained the basic troubleshooting Disappointed

    I THOUGHT I found a workaround:   (NOT !)
    * disable wrist heart rate BEFORE training
    * after 10 min training: pause training - enable wrist heart rate - resume

    * worked for 1st training, 2nd training: 90 % ok

    Today interval 5 x 800
    after 10 min: HF on: wrong! + 1 st int: wrong !
    2nd: picked up the right HF
    3rd wrong
    4+5: ok

    FRUSTRATING !!

  • 0 over 1 year ago in reply to stevendessein

    Yes , really frustrating. As said in previous post I have wrong (crazy) HR when walking outdoor  (with or without walking activity, or running activity but walking). Lucky enough not when running   . I tried to disable HRV recording and setting smart recording (instead every second) but  didn't  work  as other tons of test. At this  stage weekly Intensity minutes is useless,  since every time I  walk outdoor generates false data. I have FW 14.15 . I noticed that now is out 14.17, but Garmin declare minor modification. No mention of HR data. Using always my old Venu on the other wrist,, never same issue.

    May be the new "Elevate" HR sensor described in the specs of 255  means  " elevate (Higher) HR data" ....  :)  :)