Not much to add on this. Vaguely interested in my pulse rate, but only when its 45ish and I can think “ooh, I’m quite fit”. Not interested if it’s much higher.
I’m only posting to say how much I enjoyed this phrase!
‘Takes some of the guesswork out of deciding how you feel’
You knew what I meant though. You can feel subjectively good and yet once you get on the bike, you go like a drain. Or conversely, you feel a bit ropey, but on the bike you actually go well. Using something like ithlete gives you a better indication of how well recovered you are than how well you feel. Or something like that. I don’t actually feel anything any more. I just do what ithlete suggests and alter the way I feel accordingly.