Heart rate reporting too high when running

[CharlieWade]

Wearing the band snug fit, so it does not shake or move (in relation to skin) while running, keeps heart rate locked.
With non snug fit, the rate was higher. With snug fit, it was much lower.
I think the snug fit is more accurate.
Hope this helps.

That's definitely true, but also wearing it higher on your wrist and not on the joint helps. Movement of your wrist during exercise will break the light seal required to get an accurate reading.