Originally Posted by
HTupolev
The point of high RPM isn't energy/oxygen efficiency, it's reducing torque to keep the leg muscles from exploding.
(Similarly, the point of high torque is to avoid spinning out. The body has a lot of bottlenecks, and it's all a balancing act.)
I get what the supposed idea is, however I find I tire faster above 85-90 rpm or so, which is consistent with the finding, that just spinning the crank at high rpm is tiring even if no real work is produced.