Sleeping In On Weekends May Not Make Up For Sleepless Weeks

Sleep is one of those things that most people want more of but never seem to get enough of. And that's more than just frustrating. According to new research, a lack of sleep won't only give you dark circles. It can also put you at risk for serious health problems.

How often do you try to cheat sleep?

Are you one of those people who gets just four or five hours a night during the week — and then tries to catch up by sleeping in on Saturdays and Sundays?

If you think that's a healthy way to satisfy your sleeping needs, researchers say the body doesn't actually work that way.

"Burning the candle at both ends really builds up a debt that can't be repaid in simply one long night of sleep," said Dr. Charles Czeisler, a sleep specialist at Harvard Medical School who co-authored a new study (PDF) that finds a difference between short-term and long-term sleep loss.

You can compensate for short-term sleep loss, Czeisler said, with just a few good nights of sleep. But long-term lack of sleep is harder to bounce back from — and can actually do lasting harm.

"People who haven't been getting enough sleep on a regular basis," Czeisler said, "are going to fall apart."

As you become more and more sleep-deprived, you have a tougher time staying focused and maintaining your stamina. You also have slower reaction times. You may even start nodding off.

"Now, if you're sitting in bed trying to read when that happens or watching TV, it's not going to be a disaster — you're just going to fall asleep," Czeisler said.

"But if you're driving a car, operating heavy equipment, or if you're trying to take care of a patient, then that could result in catastrophic errors."

Long-Term Health Consequences

It's not just brain function that goes downhill.

Long-term lack of sleep can cause cardiovascular problems, weaken the immune system and change your metabolism in ways that result in diabetes or obesity.

Czeisler also says that if you regularly get a good night's sleep, which for most people means about eight hours a night, you'll be more efficient in everything you do — and you'll feel a lot better, too.

You may not realize you suffer from chronic sleep loss because occasionally sleeping in gives you a false sense of recovery. Plus, the body's internal clock usually gives us a second wind in late afternoon that helps us get through the day.

If you suspect you are chronically sleep-deprived, ask yourself why.

If you work two jobs or double shifts, that's one thing. But Dr. Dan Cohen, a researcher at Brigham and Women's Hospital and the study's lead author, said there may be activities you could give up.

"People need to be honest with themselves and prioritize how much is staying up and watching The Late Show compared to getting an extra hour of sleep," Cohen said. "Which one is more important?"

The Importance Of Napping

Cohen also said naps are good because they help chip away at long-term sleep loss. But if you simply can't find the spare time to get more rest, it is not clear how long it takes to undo that damage.

"We know certainly that it takes longer than days, but whether it takes weeks of getting eight or more hours a night of sleep in a row to fully recover and restore the brain, we just don't know," Cohen said. "It's probably longer than we've thought in the past."

One more piece of bad news: Caffeine and sleeping pills only help counteract short-term sleep loss, not long-term tiredness.

If you're chronically tired, Cohen recommends sneaking in a cat nap whenever you can.