I've experienced sleep running while in the military during training exercises. In one they kept us going for a week on minimal sleep (four hours of "rest" out

I've experienced sleep running while in the military during training exercises. In one they kept us going for a week on minimal sleep (four hours of "rest" out of every twenty-four). On day four I fell asleep while running in formation at night and woke up 5 or so hours later as I was being roused for my guard rotation. My "battle buddy" said I didn't behave any differently than usual, just quiet. All told, I blacked out for about a half-hour. My experience wasn't uncommon, I'd say about 10% of us experienced something similar during that particular exercise. The human body is an amazing machine.