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Inaccurate Heart Rate Fenix 6 Pro and HRM Pro?

Brett M
over 3 years ago

Hello,

Background: I'm 32. I started running regularly 3 months ago using only my Fenix 6 pro to track data. My average heart rate during runs seemed to be increasing over time, and my VO2 max increased from 39 to 40 over the same time. I am in noticeably better shape than when I started running, but the data didn't seem to be supporting that. Here is an example:

January 21 average HR 156, 6:14/km pace https://connect.garmin.com/modern/activity/8158338826
February 26 average HR 173, 5:24/km pace https://connect.garmin.com/modern/activity/8364095417

After reading several threads in the forums about inaccurate wrist heart rate data, I decided to get the HRM Pro to see my "true" heart rate during runs.

My first run with the HRM Pro on March 11, average HR 182, pace 5:33/km and I set a new "running max heart rate" of 197 https://connect.garmin.com/modern/activity/8439494110
Todays run with HRM Pro average HR 182, pace 5:49/km https://connect.garmin.com/modern/activity/8451850524 

After todays run, my VO2 Max dropped from 40 to 39 and my Training Status went from 'Maintaining' to 'Unproductive'

This data can't be accurate, can it? 
Also, I followed all the advice from the Garmin support website about erratic heart rate data with the HRM Pro before my run today.

My running heart rate zones as of today (I have never edited them):

Any help would be greatly appreciated.

Thanks,
Brett

  • 0 over 3 years ago

    Now you've got a proper heart rate monitor for running (the WR is fine but if you're getting serious and it sounds like you are, a chest strap is the way to go) - do a LHR test.  This will set your heart rate zones for you, you'll probably find what it'd auto-set was way out.

    Get out there, keep running with the HRM and you'll find you get accurate information over time.  It'll have "gone funny" now because suddenly the data has changed due to the new accurancy you've got.  Also, make sure you have your weight set properly, a lot of the metrics take that into consideration.

    Give it a few weeks and you'll be back and happy with the information it's providing I'm sure. Just keep using the HRM.  Also - make sure you get it nice and wet/use electrode gel. Sometimes my HRM run will tell me my heart's going at 240bpm if I put it on dry... If I was doing 240 I'd past dead and moving into the afterlife.

  • 0 over 3 years ago

    One thing that can be an issue with heart rate straps is you can get poor electrical contact between the skin and sensor pads at the start of a workout when the skin is dry. This can lead to HR readings that are too high. It generally resolves itself 5-10 minutes into a run as you begin to sweat. This is especially the case in cool conditions - I note the 2C temperature in your run.

    Pre-moistening the sensor pads on the strap can help ensure good electrical contact from the start. Some people lick them (gross), some people rinse them under the tap. Personally, I just run a wet finger over the pads.

    I note from the 2 runs you have posted, the HR data doesn't start until you are a minute or so into your run. When you open the run activity, you should wait until the HRM-PRO connects BEFORE pressing the start button - it will flash up a message when it has connected.

  • 0 over 3 years ago

    According to my 1 year experience with FR245 and 1 month experience with Fenix 6 the optical HRM in the watches is pretty accurate when you don't do intervals or sprints.

  • 0 over 3 years ago in reply to mcalista
    mcalista said:
    Pre-moistening the sensor pads

    Correct, but some folks like me like a slow warm-up, start sweating too late and then the pads have dried up. Soaking the part of the strap with the electrodes for 5-10 mins in water works extremely well for slow starters :-)

  • 0 over 3 years ago in reply to Data

    So, more of a pre-flooding then? Laughing

  • 0 over 3 years ago

    Hello, what I see is that you havent done LTHR test and your heart rate zones arent well defined. Put some watter on strap before you put it on body. After that do daily sugestion and a lot of base running. I'm 39, and 6 months ago I had 38 vo2, and now it's 44.