In ballet we used to say that for every day of class you missed, it took two to get back to where you'd been before you missed. Just a saying, but that seemed to be pretty much true to all of us. That has not been the case for me with cycling, where I find I can miss more time with less setback. I'm guessing it's because of the precision and control that ballet required. Of course I feel it if I've been off the bike for several weeks--slower, more sluggish--but the rebound isn't nearly as bad as it was in dance.