A sleep debt your body can’t repay

By Bryan Gilmer • Published: December 4th, 2009
Category: Health in a Heartbeat

There’s a saying at some colleges: Sleep is like a bank… you can borrow from it, but you’ve gotta to pay it back. Turns out, that may be true only in the short term, Northwestern University researchers have found.

Scientists… like most everyone… have long known that if you don’t get enough sleep one night, you sleep like a brick the next as your body tries to catch up.

But what if you… or a colicky baby or brutal work schedule… deprive your body of adequate sleep for days or weeks at a time? The startling answer is that your body may just give up on trying to get the sleep it needs. It will allow you to default on your sleep debt.

If that sounds bad, it is, both physically and mentally.

Researchers kept animals awake twenty hours a day for five straight days. After the first day, the animals’ bodies tried to compensate by making them sleep more deeply the second night. After that, though, their bodies gave up. Even given three extra days to sleep as much as they wanted, the animals recovered virtually none of their lost sleep.

That’s alarming, because losing even two or three hours of sleep a night severely impairs your thinking and reaction time. And it damages your immune and cardiovascular health.

It seems your body thinks you keep depriving it of sleep because you’re in imminent danger. So it tries to sacrifice your long-term well-being for short-term survival.

And that’s quite a price to pay.