Was it picking up your footsteps instead of your heartbeats?
No - but my watch strap has a few busted holes, so its either a tad loose, or far too tight. So most likely not getting a good read. Or I'm just a mutant...
Just wondered because HR was really close to cadence.
Yeah, and a loose band would probably contribute to the watch bouncing at that rate, disrupting reading. When I bought this replacement band, I'm sure I got two, but damned if I can locate the other unused one. Of course if I order a new band, the other one will come out of hiding..
That's what I meant by picking up your footsteps. Looks like there might have been a few periods when it made contact, right? (Is 170 realistic?)