I’ve always noticed that when I’m running on a treadmill, my HR tends to drift up far higher than it does when running outdoors. For example, the other day I ran RRe4, and despite my pace being well within my Z1 range, my HR was up at the top end of ZX by the end of it, and the perceived effort was certainly trending upward towards ZX effort range. At first I thought my treadmill calibration was off, but I timed & measured, and it’s pretty much spot on with what it’s set to. I usually run by pace, but should I instead run by HR indoors? What’s recommended in this situation?
That is highly unusual. Given your confidence in the machine’s calibration and your RPE’s corroboration of your HR readings, I suggest you perform an HR-based threshold test on the treadmill you’re using and train by HR using the zones thus established.
Based on other things I’d read, I thought it was unusual too. Just to clarify, you’re suggesting the 20-minute test to play with pace until my HR settles in at my established threshold HR, to set pace zones for the treadmill? Or do a full threshold test to set a treadmill threshold HR and set HR zones?