I've worked 3rd shift for almost 12 years now. I don't think your body, regardless of the amount of sleep you get,ever gets use to it, and I make sure I get 7-8 hours sleep everyday. I get off work at 7AM, and by the time I get home and unwind, I get to bed around 9AM. I then usually get up when the kids get home from school that afternoon. But I've been known to lay back down and take a nap before work.
They say working 3rd shift shortens your life span...... so I have that going for me.