why is the wrist heart rate so wrong during rest or first mile of a run

I know wrist heart-rate is terrible in general regardless of make or model but really disappointed on a $500 watch that is practically the flagship for Garmin

When I am sitting idle, I can wear both my pressure cuff (which is not optical so fairly accurate) and my optical finger pulse-oximeter and that all agree my pulse is in the low 40s

But not the Fenix, at that moment it will typically show double that, like in the 80s, maybe 70s

Then almost every single run, the first mile or so always shows really high heart rate, then suddenly snaps into normal predictable easy/aerobic zones.

Tried wearing it normal, inside of wrist, very tight, looser, no difference.

To be clear, eventually it shows reasonable HR, and after a run it will then start to show the same HR as the cuff and finger-pulse-oximeter.

I suspect it's not just the sensor but rather the software algorithm learning poorly.

Maybe related to having a low resting heart rate but not sure and if so, the software really should deal with that.

0 rinserepeat over 5 years ago

here is a classic example from today, you can see the HR is wildly wrong until it wakes up around a half mile in where it start to more accurately reflect pace+effort

it's not like this is chest strap HRM where sweat sometimes needs to build up to improve contact

not sure about this but I'd almost suspect that switchover point is where you get the first alert about performance increase/decrease (the +1 alert)

it's like it wakes-up and self-adjusts

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0 bcdrachman over 5 years ago

I made my own adjustable wrist band using velcro so I can slide the watch up just above the elbow with the green light over the brachial artery while doing a workout. For me this works better than a chest strap and is more convenient.

0 hborick over 5 years ago

I'm had my Forerunner 645 for a year now and am still quite frustrated in it's inaccuracy at times. I really can't figure it out. However, it seems that it's more prevalent when I'm running slow. See the two pics with different paces. Recently while running with my wife at a 12:00 pace, my HR was reading 160, however I stopped to take my pulse... 96. So somethings a bit off. And the watch has been replaced.
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0 3087072 over 1 year ago

I know this is old but its something garmin seems to ignore or never address. I never have this problem with apple, fitbit, samsung etc but it does happen on garmin watches although newer watches have gotten better in this regard. Tells me its a software issue and they just refuse to acknowledge it. my Epix just did this as well for the first time and its super frustrating because I had a 2 mile run and the first 6 minutes my heart rate read 72 making the workout useless. This can't be that hard to figure out!