On my last 4hr run my HR was fine the first 1/2, then jumped about 20 beats too high and stayed there for the 2nd half, it didn't spike or lock...it changed with my pace but was consistently 20 beats too high regardless of my pace. I wore the watch snug, below my wrist bone and I have just about the whitest skin possilbe...Anyone else run into this problem?? I understand it won't be as accurate as my HR strap, but 20 beats???
They should really make it clear (not just Garmin, but any company making a device with OHR) that optical wrist based HR sensors are only useful for monitoring day to day HR changes; which they can do very well and the data can be useful.
During exercise they are practically useless.
If you want accurate HR while exercising then you have to bite the bullet and go with a HR chest strap.
It is worth remembering the chest straps have their own problems, like erratic readings in the 1st 10 minutes in cold/dry conditions, the buildup of sweat over time meaning the strap itself (not the sensor) needs periodic replacement.
I find the OHR almost identical with a chest strap for steady state cardio like running. I still use my chest strap for intervals, and for cycling.
For best results:
* wear the watch on the fleshy part of the wrist, away from the wrist bone.
* make sure the strap is snug
* let the OHR get a firm lock on your pulse BEFORE starting the activity - wait until the heart symbol stops flashing.