There is an hours component to some adaptations, where it’s more about low-intensity heart and leg muscle contractions. And it should be obvious given the success of “old-skool long steady distance” 20-30 hours/week base training. Vaguely recall seeing at least one pro doing that recently.
My hours story…
Season 2016-2017… 6 hours/week to hit 270-280 ftp, 19kJ anaerobic capacity, and 50-70 minutes at threshold:
Those red triangles are rides at 0.9 IF and above. A whole lot of “red / high-intensity / high IF” riding from late October to June.
That is likely my limit for doing high aerobic work, and even though it was loosely structured there was a LOT of stimulus:
Season 2022-2023… 7.5 hours/week to hit 270-280 ftp, 17kJ anaerobic capacity, and 30-50 minutes at threshold:
Almost no red high IF workouts. Mostly a sea of orange IF workouts, the equivalent of mid endurance to upper tempo. We didn’t do a lot of tempo, but we did do a lot of dialed in intensity vaguely along the lines of this study Dissociation of Increases in PGC-1α and Its Regulators from Exercise Intensity and Muscle Activation Following Acute Exercise where you go hard but not too hard.
Less high aerobic work
but more recovery built into the workouts, more overall conditioning / endurance riding, and my coach was focused on eliciting adaptations versus brute forcing interval sessions.
We did not focus on longer threshold, and only a couple anaerobic capacity workouts in the spring. So those were lower versus the earlier period. And the earlier period I was 55 and better recovery.
High stress job, work long hours, old enough the kids are gone but dealing with my mom’s issues, yada yada.
When I hired a coach in August 2020, I wanted to believe that could all come true. And it did.
Your mileage may vary and all that.