Originally Posted by 96Gatorcise
people avoid them for the same reason you stated before, they make you sore, really sore because they make you use more weight then you can concentrically contract. Hence you breakdown more muscle fiber then you normally would.
Strangely, or perhaps not, they just made me more tired than sore. In my experience - and this is echoed by others - pecs and quads are more apt to get sore. But the one-armed pushup is less a pec exercise than, I would say, a triceps/lats exercise also requiring better-than-average core stability. The pecs, I would say, play a comparatively minor role.
Now, I will say it's hard on the lumbar spine. Dr. Stuart McGill measured compressive forces at 1,250 pounds during the OAP. Aches, strain and fatigue are the primary aftereffects for me.