I see what you're saying, and did not mean to push the catabolism angle so far. My basic tenet was only a rough analogy with somatic regrowth, a cycle alternating between stimulation and rest. This is just an answer to the OP's question which seemed to infer an either/or situation.

It is a fine line, of course, between just a little over and too much, but then there's the art. You can push yourself too hard physically, too. You only do more if you push yourself to do more, and that applies mentally as well as physically.