My wife does all the damn time. She would work out in our shop and when it was too cold or too hot she refused to go out there. few days would pass and before long there she would be, mooping on the couch of how she felt like a lazy lard ass. There's no talking to her after that. She's hot as hell, but she needs to realax and stop reading Cosmo!
Does that "endorphin" boost you get become a craving?
I work out, and no I don't get down when I miss a few days. I think this is because I'm an herb-aholic and I don't often skip using my accupressure mat, so it must balance things so that I don't get down when I skip my work outs.