Insomniacs get all the attention. Pop songs lament the restless nights of the lovelorn, and drug ads describe the soothing sleep you can get if you pop the right pill.

It’s no wonder people’s eyebrows shoot up when Shawn Youngstedt tells them he’s studying the health hazards of people who sleep too much.

"To many, it seems crazy, counter-intuitive," says Youngstedt, an assistant professor of exercise science in the University of South Carolina’s Arnold School of Public Health.

Yet studies have documented the health risks of "long sleepers" – those who report needing more than eight hours on the mattress each night.

Most significantly, he said about 20 studies involving more than a million people have shown that long sleepers have a greater risk of dying than do those who sleep less.

(Researchers ruled out the possibility that the long sleepers simply had fewer diseases to start with.)

If sleeping too much can be hazardous to one’s health, does it follow that long sleepers should try to sleep less?

That’s the focus of the unusual research at USC. Youngstedt and colleagues are testing long sleepers to see whether restricting their pillow time has any ill effects.

Researchers rule out conditions such as sleep apnea, severe depression, excessive daytime sleepiness and abnormal blood-sugar levels. Then the long sleepers are assigned to an eight-week treatment plan.

Half of them reduce their time in bed by 90 minutes a night. (Most average 7.5 hours of sleep, down from nine hours.) The other participants stay in bed for the usual time. All participants keep diaries and have their daily and nightly movements monitored by an actigraph, a device worn on the wrist.

"The bottom line is that we’re finding people are indeed able to reduce their time in bed with no significant effects," he says. Some participants have continued to restrict their time in bed after the study, he adds.

"You know how you feel kind of lethargic after spending too much time in bed on the weekend or over a holiday? There’s some evidence that long sleepers tend to feel that way all the time," he says.

Youngstedt invariably is asked whether long sleepers should try to sleep less.

"My answer to that is, it’s too early to advise people in that direction," he says. "On the other hand, I feel completely comfortable advising someone who sleeps six hours and feels fine that they don’t have to worry about getting eight hours," he says.

"They might actually live longer."

© 2006, The State (Columbia, S.C.).

Distributed by Knight Ridder/Tribune Information Services.