To sanity check some battery consumption changes, I disabled wrist HR on my FR255 last week. I do not have any paired sensors.
I was surprised to notice that my watch is still reporting intensity minutes during the week. Is anybody familiar with the heuristics Garmin is using here? It may be that it is just treating the timed duration of my walk activities as base intensity minutes.
Normally, with the wrist HR active, I would get different intensity minute figures from the same walking route. It could range 20% than the elapsed time all the way up to 20-50% more than elapsed. I believed that this variation was based on the uphill pace I did on some days versus others and its affect on my HR.