I'm kind of the same way. I'm finishing my degree so I've been sitting in classes taking placement and assessment tests for 2 days straight. Yesterday was supposed to be my off day, today I was just mentally exhausted and just crashed. Since I don't keep regular hours you couldn't pay me to work out in the 4-9 pm range (gym happy hour) but even if I have to go in the middle of the night tonight I'm going.

Working out is what help keeps my sanity and a day without it just doesn't feel like a day.