Hey All,
I have very thin/bony wrists. When I dorsiflex, they go concave. It's been a known issue for me with various wrist HR products that when I'm active the accuracy of wrist HR sucks. I've tried moving it up my arm, but it's unreliable.
Correct me if I'm wrong here, but give this, most of the advanced features by first beat that rely on HR (training effect, body battery, stress, etc) won't be reliable unless, of course, I'm using a chest strap during activities.
I'm just trying to figure out what I can and can't really on for data.