I'm with Yellow. I like pushups. They ease my frustration. Sometimes I go in an exam room, lock the door, put down 4 paper towels on the floor, take off my lab coat, and do 20 pushups. In a skirt and heels, whatever. I can cope with whatever's out there much better after some pushups!

I must say, though, that the first summer I rode a lot, my arms got much more muscular. I think it's just controlling the bike on city streets. I don't know though, it may have been all the pushups! It was a largely frustrating summer...