Originally Posted by
base2
.
I'd trust nothing unless it was 60 minutes. The rest is just guesses.
No.
The relationship between X minute power and critical power or 1 hour FTP is pretty well known. Note how we're arguing several percentage points here. If your 5 minute maximum power is, say, 350W we can be
very confident that it's between 250W and 300W.
Probabilities aren't
just guessing.
Furthermore, 1hr tests are something people will, at best, rarely do (especially if required to do it on a trainer; I just can't imagine what could possibly motivate me to do that), so estimation based on recent best efforts is very valid and useful for setting training zones, as well as pacing. If you can't do your training based on these estimates or it destroys you when it shouldn't, now you know they were too optimistic 🤷