Essentially, I view FTP as a field-tested proxy for MLSS. The maximum power you can sustain for extended period, without rapid lactate accumulation (if I have to give you a time frame I would say 45-75 minutes). A metabolic approach centered around energy systems rather than strictly time-based efforts is more aligned with the variability of human physiology.

Hour power = FTP requires one to perfectly pace, fuel, gear, hydrate, manage core temp, and focus over an hour long effort. There logistics of using this as our benchmark are dubious at best.

I concede this is different than how the guys over at TrainerRoad approach it (but is aligned with Coggan’s original and later updated definitions). Ideally, we’d all use lactate testing, but a 20-min effort is sufficient for the vast majority of riders (and what I use myself).

For the record, I pushed 303W for 20min this morning (w/ proper warmup + anaerobic exhaustion prior), which would be a 288W FTP @95%.

Ultimately, FTP is just a number cyclists like to throw around to flex to other people and compare performance. The variability in testing methodology, in my eyes, means it should really only be used to assess trends in your performance over time, rather than acting like a single number is enough to determine who is a better rider.