Well most people over work, what usually happens is this: You lift heavy weights, the body takes around 1 week to rebuild your muscles, and you maintain that muscle for another week or two. You can still make improvement exercising 2 to 3 times a month. I just do one set till complete failure, so benchpress, squats etc. When people overwork I compare that to an elevator. If I push the button once the elevator comes down, it won't come down any quicker if I push the elevator button 10 times. The body needs time to heal, and working more is sometimes working less. If you ever find you get to much muscle from weights all you need do is stop. So far all it has done is keep me skinny.