Hearth rate not very accurate

[Kangasvuokko]

I bought Galaxy watch 4 few weeks a go to check ECG. I’ll also used it during mountain biking and compared it to Polar strap H10 monitor. Results are bad. Yesterday I did a 1 and half hoir ride. Real avarage heart rate was 111 bpm and Samsung showed 141 bpm! 

That is not even close. Often the difference is about 20 bpm …avarage during 2-3 hour riding. It can be 100% wrong in shorter time periods. Why!

Any ideas?

[BigGaben]

Could be because it's measuring in intervals of every 10 minutes instead of continuously, a bad fit on your wrist, or simply because it's moving around while biking. The watch is using a camera to measure your heart rate, which is a very different technology compared to a strap monitor, and has physical limitations such as if the watch is moving around on your arm.

[Kangasvuokko]

I think I have a continues hearth rate on on my watch. So thats not it. I did shave hair of my wrist, but it might be a bad fit still. It can be moving during riding…but it cannot be thighter on my wrist.

Also as I do my ECG test it shows haert rate like 40 bpm and when a check current heart rate on my watch…same watch that measured 40…it shows 70?

Have to check the 10minute thing …

[BigGaben]

Could you try to move it up a bit on the wrist too? And I've been thinking about if there makes any difference if you put the watch on the other side of the wrist, like "backwards", if you would like to try and give the results? I'm curious about how it performs in different scenarios!

[Kangasvuokko]

Very fast experiment. Sitting and Watch rifgt way on wrist 72 bpm and backwards 62. Same time hearth rate with polar strap 48.

No movement, watch up on wrist…

I think its even worse when exercising because heart rate is faster and error is even bigger.

[BigGaben]

Yeah, would be interesting to see the curve readings, to find out what might cause the error. Does the curve look periodically stable, or does the curve behave randomly when measuring?

[Kangasvuokko]

When I measure ECG, I need to be very careful to get a good result. If I push a little too hard on the watch, curve is very abnormal…sometimes it takes three or four attemps to get a good reading.

Very strange is that ECG might give a hearth rate like 42 and watch a current hearth rate 70 something…

[BigGaben · Accepted solution]

And I guess you have tried to recalibrate the ECG on the watch with a real blood pressure monitor?

[Kangasvuokko]

Blood pressure is quite accurate. I do not know how to calibrate ECG.

[BigGaben]

My bad, I just installed the ECG app, and it required to first calibrated the lood pressure. So I mixed of up!
Gonna do some research, and see if I find an answer to the problem, and reply as soon as I find something. Thanks for bringing up the discussions!