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The HR values are too low during an activity like biking

flavi85
4 months ago

Hey,

I've noticed that during high/intensive activities like biking my fenix 8 solar 51mm is reporting hr values too low comparing with my chest band - hrm pro plus... 107 vs 138 (which I think is the correct value)

If I remove my watch and after I put it again on my hand the values are almost the same.

The sensor is very clean, nothing is obstructing it and this strange behaviour happens at the very beginning of my rides.

Thanks!

  • 0 4 months ago

    Hey, I've been having some similar issues as well (Fenix 8 47mm Amoled V13.14 Beta) - The other day when I was still warming up on my run it was showing 155, then I took it off and back on again, then a little later it stabilized to around 135-140. Not sure if the cold weather outside has anything to do with it.

  • 0 4 months ago in reply to LyuboV

    I think you're right regarding cold weather conditions.Outside temperature was somewhere between 2-3 degrees Celsius. Maybe the sensor has some issues on cold conditions. I hope that these are only software issues, but will see. Similar issues were reported for skiing activities for which it will make more sense in terms of operating temperature.

  • 0 4 months ago in reply to flavi85

    From a Google Search

    Your wrist-based heart rate monitor is often less accurate in the winter if you have poor circulation in your hands and wrists. If blood flow is reduced, there is less volume coming in and out with each heartbeat, making it harder to detect a change in light reflection.

  • 0 4 months ago in reply to kstate1980

    Yeah, cold weather conditions will induce cutaneous vasoconstriction

  • 0 4 months ago

    Mine does this too. Many have mentioned cold weather but mine does this when riding the indoor bike trainer as well. In both steady state and interval type workouts it's never within 30-40bpm of what my chest strap paired to bike computer say. 

  • 0 4 months ago in reply to bglover11
    bglover11 said:
    In both steady state and interval type workouts it's never within 30-40bpm of what my chest strap paired to bike computer say. 

    Have you started the corresponding activity profile? Otherwise the sensor remains in low power mode.

  • 0 3 months ago

    I have this issue with the cold as well, and find it very frustrating. 

    One thing that does fix it most of the time is to put the watch on the other side of your wrist, facing in towards you, then start the activity so you go into the GPS lock screen for it.  Put on your cold weather gear with the watch on the GPS lock screen and move around a little to get your heart rate up a little bit.  5 minutes or more like this, then go out, hit start and do your thing.  I usually do some hip stability exercises and/or a little core work.  Nothing crazy just enough to warm up a little then go out for a run.  This has been mostly working with 10-20F temps outside during runs.