Most of us sleep in the same way. Collapsing in bed in the late evening, then spending the next 8 hours – if we’re lucky – dream and snoring until the alarm clock rings. But that’s not how everyone does it. Some people divide their sleep into two or more shifts. This is called segmented sleepand there’s a lot of noise that this is the way to go in today’s fast-paced world.
But before you dive in and schedule chores in the middle of the night, think carefully about whether it really suits your lifestyle. And pay attention to the warning signs that this alternative sleep hourly puts you in a funk.
How it all began
Segmented sleep seems all the rage, but it’s not a new idea. In pre-industrial times (and before electricity), it was normal to get up for a few hours in the middle of the night, according to historian Roger Ekirch, author of At the end of the day: the night in the past. People spent their free time praying, smokinghave sex or even visit their neighbors and then go back to sleep until morning.
We can be wired to sleep in two periods. A study by the National Institute of Mental Health looked at how well people slept when given 10 hours of light a day, about as much as a winter’s day. The researchers found that these people closed their eyes in two slices, with a few hours of wakefulness in between. It’s also closer to how animals sleep.
Some people follow this split schedule today – using the waking period in the middle of the night as a creative time to think, read, meditate or work.
“There are people for whom this seems like a productive way to live and it suits them just fine,” says Brown University sleep researcher Mary Carskadon, PhD. “But it’s hard to do if you have family and a job you have to do every day.”
Sleep in 2 shifts
Valerie Robin, then a graduate student in Atlanta, tried segmented sleep for a few weeks in 2014 after reading her story. She went to bed when it was dark, then got up in the middle of the night to read, write in her diary or talk on the phone with friends in other time zones. She woke up on her own once the sun came up.
“I was calm,” Robin says. “All day and even at night. I had read that it was like a natural meditative state at night, but I was like that during the day too.”
Although she felt rested and even had extra energy, Robin grew tired of missing parties and appointments and returned to a more conventional schedule. “If everyone slept like this, I would rather sleep like this,” she says.
Is it healthy?
Opinions are divided on whether segmented sleep is safe. Since there hasn’t been much research on the effect shift sleep can have on your health, it’s best to avoid it unless there’s a reason you need it. to sleep that way, says Clete Kushida, MD, PhD, medical director of the Stanford Center for Sleep Medicine.
“There are so many unknowns,” he says. “[Is it] safe in the long term? How does it vary from individual to individual? How is age taken into account, or medical conditions, or sleep disorders?”
But Carskadon says she isn’t aware of any evidence that sleeping in two shifts at night causes health problems, so it’s okay if you naturally sleep that way. “I don’t think they should worry if they otherwise feel healthy, happy and fulfilled,” she says.
One thing to keep in mind if you’re trying to sleep in segment. Artificial light in the middle of the night could impact your circadian rhythms – the internal clock that controls your body’s processes.
So keep the lights dim at night, suggests Carskadon. And if you can, stay away from light that looks blue – like LED bulbs – because it has the biggest effect on circadian rhythms.
Reduce total sleep
Some people divide their sleep into a schedule of 24-hour naps, sometimes called polyphasic sleep. It is often designed to allow you to get by with less total rest.
That’s a bad idea, Kushida says, because adults need at least 7 hours of sleep in 24 hours. There can be major consequences if you cut back, he says. When you’re sleep deprived, it can:
- Change your metabolism
- Increase the hormones that make you eat more and to gain weight
- Affect your learning and memory
- Increase your accident risk
And it won’t help you do more either. “You may be doing more harm than good thinking your performance will improve,” Kushida says.
If you want to try a different sleep schedule, pay attention to how you feel. Beware of signals that it’s not working. You don’t want to put yourself and others at risk because you’re sleep deprived and trying to stay awake when your body says it’s time to close your eyes, Carskadon says.
Watch out for these signs of trouble:
- Struggle to focus
- have a short temper
- Take risks you wouldn’t otherwise take
- feeling extremely sleepy
- Falling asleep at the wrong time, such as in class or while driving