I would say for HR to see if you’re getting faster, it would be matter of tracking efficiency factor (ratio of Pwr/HR). For example, I’m doing SSB1 HV and a lot of the intervals avg around 90% so I can see over time whether that EF changes much. In this particular phase, my EF has been generally 1.68-1.7 and I’m doing week 4 now, and so right now I’m not really anticipating any changes to my FTP.
Aerobic decoupling is a nice measure but I’m under the impression it’s of pretty limited benefit except for long steady efforts where ideally one would see under 5% drift (that’s used as kind of a rule of thumb to see if one has base fitness).
Anyhow, curious to listen to the discussion!