As I said I crunch my own numbers. It keeps me sort of in tune with my body and pushes me to explore further. I try not to overcomplicate things and instead look for the best angles though. For example, I was on the train yesterday, resting and doing some online learning, but my HR and HRV this morning are terrible. My body hasn't recovered, so it definitely doesn't make sense to train today - it wouldn't contribute to my HM140 goal. Was it a lack of hydration, junk food at the station, or just the stress of traveling? Actually as a result of all this, I’ll probably look into how dehydration specifically affects muscle recovery and performance…