What Is Segmented Sleep and Is It Healthy?

But before you dive in and make plans for some middle-of-the night chores, think carefully about whether it's really suited to your lifestyle. And watch out for warning signs that this alternate sleep schedule is putting you in a funk.

Most of us sleep the same way. Collapse into bed in the late evening, then spend the next 8 hours -- if we're lucky -- dreaming and snoring until the alarm rings. But that's not how everyone does it. Some folks break up their slumber into two or more shifts. It's called segmented sleep , and there's a lot of buzz that it's the way to go in today's fast-paced world.

Segmented sleep sounds trendy, but it's not a new idea. In pre-industrial times (and before electricity) it was normal to get up for a couple of hours in the middle of the night, according to historian Roger Ekirch, author of At Day's Close: Night in Times Past. People spent the free time praying, smoking, having sex, or even visiting their neighbors, then went back to sleep until morning.

We may be hardwired to sleep in two periods. A study by the National Institute of Mental Health looked at how people slept when they got 10 hours of light a day -- about as much as on a winter's day. Researchers found that those folks got their shut-eye in two chunks, with a few hours awake in between. That's closer to how animals sleep, too.

Some people follow that split schedule today -- using the middle-of-the-night awake period as a creative time to think, read, meditate, or work.

"There are people for whom that seems to be a productive way to live and suits them just fine," says Mary Carskadon, PhD, a sleep researcher at Brown University. "But it's hard to do if you have family and a job you have to go to every day."