Somebody works their butt off and he's a devil. Both sides of that are example are overstated, of course. I don't remember any lottery winner ever becoming a national hero. And working your butt off is a relative term. Coal miners work their butts off.
Waitresses work their butts off.
Farmers work their butts off. Many white-collar professionals, such as lawyers and stock brokers, put in long hours. But most of them still seem to have plenty of butt left. Baseball players do not, by any stretch of the imagination, work off any part of their bodies. Even the parts that need it.