well submission is about pleasing the Dominant.....
i maintain my looks according to my Dominants likes/dislikes. i want Him to be proud of me. As Mack said....i can tell when He's proud to have me on His arm....and that's the best feeling in the world.
Oh course brains and personality come first but just as you do a puzzle to excersise your brain....you must also run the treadmill to keep those legs in the best working order.
but it should certainly go both ways. i would get resentful if i was expected to run a mile everyday and maintain a certain weight but Master was at home, eating donuts, unable to button His pants.