about 76 hours, although i went 8 days with less than a combined 7 hours of quick naps in the army 'hell week' as others have described.. on day three i was so tired i nodded off for 30 minutes in the middle of a mock battle and my position was overrun. i woke up behind enemy lines lol! the strangest thing is after day 6 i wasnt tired anymore and when i got back to the barracks i still wasnt tired but then just collapsed in a black out. I think its dangerous if i could fall asleep in the middle of a battle and collapse while feeling fine i think you might crash a car or something i wouldn't recomend it.