Originally Posted by
BarracksSi
One analogy that was posted was, "Think of doing curls with a 50-lb free weight versus doing them with a 5-lb dumbbell. Which one requires more power, but also, which one do you think you can do for four hours?"
To me, mashing a tall gear is like climbing stairs, while spinning is like going for a jog. Climbing stairs for an hour sucks, but an hour easy jog is manageable for me.
I think both of your analogies are interesting and useful.
Though to be fair it depends what one means by mashing and spinning. For me 60-70 rpm is mashing, and 90+ rpm is spinning. I don't know what I would consider 70-90 rpm... In any case they could all be pretty aerobic (though with different effects on one's muscles), because I could do any of those for an hour. I mean if you go to the 50-lb curls, I wouldn't be able to do 1-per-second (60 rpm) for an hour, I would do 10 repetitions and then have to stop... So I think the stair climbing analogy is more accurate, but the weight analogy is clearer.
Similarly sprinting can be done with super-high rpms and I think that will be anaerobic because you won't be able to keep it up very long...
Within certain bounds I think power output will be the main determinant of whether an activity is aerobic or not. The difference between higher and lower rpms (for the same power output) is that the higher rpms result in less fluctuation in instantaneous power, but more energy wasted "bouncing around".