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Optical HRM still totally wrong with 21.19 - In fact, worse than ever

Grumpy from dawn till dusk
1 month ago

Hi 

unfortunately I have bad news. You closed OHR related topics like this
https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-955-series/384760/heart-rate-values-from-optical-hrm-still-totally-wrong-with-20-26

and this
https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-955-series/362273/heart-rate-values-totally-wrong-after-update-18-22

But you were asking to give you feedback, if we encountered that bug again.
This is the case - in fact, in my opinion the optical HRM is worse than ever now.

With 20.26 I was quite ok with the measurements of the OHR while walking/hiking and for higher intensity workouts I usually use a HRM strap (beside bike commuting).
With 21.19, the OHR cannot be trusted AT ALL, even for low intensity stuff like walking/hiking.

See this heart rate values, that I recorded during an hours walk today:

The average is a HR of 70!!!
While walking one hour with a pace below 10 minutes/kilometer.

My resting HR is 48, still, this is just random. It is nowhere near the real pulse I had during that walk.
And regarding blood flow: Yes, it is cold now in Germany (4 degrees Celsius), but I was wearing a thick fleece pullover and Polartech gloves and the watch was below it all.

Yes, you may contact me and have a look at my activities and I live in Germany.

  • 0 9 hours ago in reply to Grumpy from dawn till dusk

    I experienced this problem in about 1 in 3 activities - initially the recorded heart rate would be far too low, then suddenly jump to a plausible value after 5-20 minutes. For the last couple of weeks, I have taken the watch off my wrist and put it back on when starting an activity, on the screen where GPS is acquired, and I have not seen the problem.

    My theory is that this causes the sensor to re-acquire your heart rate after it puts the sensor into high-power mode at the start of an activity.

    The problem is not related to degradation of the sensor, as my 955 is new (and I also saw the problem on my Venu 2, which has the same sensor type).