> They said the participants slept only five hours a night for weekdays. 8 hours is the generally recommended amount for a good nights sleep, so to truly bring

> They said the participants slept only five hours a night for weekdays. 8 hours is the generally recommended amount for a good nights sleep, so to truly bring balance to that schedule, they'd have a 15 hour sleep-debt to make up on the weekends, in addition to the full 8 hours they'd need to sleep those two weekend days on their own. I seriously doubt the participants were able to sleep 16 hours on both friday and saturday night to fully pay the sleep debt even at their level of sleep deprivation, so I don't think you can really say the "balance sheet" approach is wrong. Well, if you take a reference of 7 hours instead of 8, it is more possible. That's kind of what I was doing when I was in high-school: sleeping 5 hours or under on week days, so a total of about 24-25 hours over 5 days; and then sleeping 12 hours or more on week-end nights. So I was sleeping as much in those 2 days, as I was in the other 5, for a total of about 50 hours / week, which is around 7 hours per day on average. Note that I do not recommend this rhythm! Periodically during those years, I suffered from awful 3- to 5-days long periods during which I was... I don't know how to explain, like if there was a cotton wall between the world and me, I had no control over anything, everything was happening automatically, I had kind of visions of stuff that would happen not matter what I'd do, etc. I guess all of this was caused by sleep deprivation. Gee, I don't miss those periods... luckily it stopped after high-school. But all my life, I have had huge difficulties to fall asleep at night, and also suffered from stress, which doesn't combine well with the necessities of school times, work times, and other mandatory times: I generally managed to sleep earlier when there was no need to wake up early... If I ever need to wake up at 5 or 4 AM, I won't even manage to get any sleep (or 45 minutes with 10 sweaty 180 heartbeats per minute wake-up inside).