On certain days, when I haven't gotten as much sleep as I'd like, I always wonder which would make me feel more refreshed -- a nap or a trip to the gym.  Given the fact that I don't really have the option of napping at work, I tend to go to the gym, which perks me up for a bit, but then I'll often feel more tired in an hour or two afterward.  If a nap was a true option, which do you think would help you get through your day -- a nap or a quick work out?