Originally Posted by
Racing Dan
I on the contrary, find HR is pretty good at predicting what pace I can sustain at that particular day. A PM tells you what ever power you deliver (unrelated to HR), but it doesn't know if you are catching a cold, if you are about to bunk ect. Both have their merits.
Way less precision in the HR numbers, and they're too affected by other things like diet, how recovered I am, etc.