Gym Ass
When you are working out and you have excessive moisture in your ass. Irritation from sweat in and around your buttocks.
I have the worst case of GYM ASS from working out today. Sitting at this desk gave me a case of Gym Ass.
Crazy-ass Gym Mofo
Some kind of brotha or sista who spend three hours in the gym, stacks on five workouts, and drives the coaches insane.
Yes coach, I am a crazy-ass gym mofo. Live with it!