Left/right wrist: impact on optical HR sensor accuracy?

Hello Garmin friends,

I just bought myself a Fenix 5 and since I am left handed, I am carrying my watch on my right arm.
I went running and wanted to test the optical HR sensor. I started to run for 1 mile and I knew the HR reading was not correct (I've been running since now with a Suunot Ambit 3 with a HR belt) - it was about 10-15 beats under what it should have been. The strap was tight and I was already sweating.
I then proceeded to change the watch to the left arm and the reading seemed more correct there. It's a problem for me as I really find it uncomfortable to wear the watch on the left arm.
Also now, the resting HR seems too high on the left arm whereas it seemed correct on the right arm. I'm a bit lost I have to say.

So my 2 questions:
1- is there a setting on the fenix 5 to set left or right wrist? I know this existed on the fenix 3 apparently but I have not found anything on the fenix 5
2- what could be a reason for the wrong reading on the right wrist? is this a known issue?

Many thanks in advance :)

Top Replies

mcalista over 7 years ago +1

It is entirely possible that the blood flows slightly closer to your skin on one wrist than the other, making it easier for the OHR to pick up. Indeed, switching wrists is one of the steps recommended…

All Replies

0 JHRJ over 7 years ago

I've had exactly the same experience with my Fenix 5. I normally wear it on my right wrist, but have to switch to my left to go running. Even when I set it the wrist to Right (in User Profile) it alway reads way under what it should. It is very good on the left wrist, though. I had a similar thing with a Fenix 3 HR.

It's strange, but I think people like us are just too much of an edge case for the scenario to be properly tested. I don't mind switching wrist for a run if it gives me what I need, though.

0 mcalista over 7 years ago

It is entirely possible that the blood flows slightly closer to your skin on one wrist than the other, making it easier for the OHR to pick up. Indeed, switching wrists is one of the steps recommended if you are having OHR accuracy/consistency issues.

As well as band tightness, positioning also has an impact on OHR accuracy. It should be on the fleshy part of your wrist, away from the wrist bone.

Settings> User Profile> Wrist will allow you to change to left or right wrist (this affects gesture and which way the watch should expect movement in terms of step counting).

0 mans72 over 7 years ago

thanks a lot guys, really useful. Much appreciated!