Biphasic or polyphasic sleep is when your sleep is broken into two or more segments throughout the day and night. It is a very different sleep pattern from what most people are used to these days, which is one long stretch of sleep lasting for 7-9 hours, also called monophasic sleep.
Biphasic sleep used to be the norm in pre-industrial societies, and has been enjoying increased interest lately among people who either want to increase their efficiency or are looking for a way to rest that better suits their circadian rhythms. So what’s all the buzz about, and should you perhaps try biphasic sleep too?
Biphasic sleep and its benefits
There are in fact, two kinds of biphasic sleep. Sometimes it just means that you take your siesta seriously and really do sleep in the afternoon, like some people still do in Greece and Spain. Or it can be that your night sleep is broken into two parts with a short break in the middle.
According to the historian A. Roger Ekirch, this second kind of biphasic sleep was the norm in pre-industrial Europe. In his book At Day’s Close: Night in Times Past he describes how people would go to sleep shortly after dusk and would have two stretches of sleep through the night with a break in the middle that lasted one-two hours. During the break, he says, they would do light activities that could be done by the light of the moon, like sewing and having sex (that’s right, NOT checking their smartphones).
In the 1990s, psychiatrist Thomas Wehr wanted to see if given the opportunity people indeed gravitated towards a biphasic sleep schedule. He conducted an experiment leaving participants in darkness for 14 hours for several consecutive weeks, and found that people eventually did adopt a biphasic sleep pattern.
Biphasic sleep has some proven benefits for our health and wellbeing. Some scientists today believe that naps are really good for us, and have the ability to improve memory, alertness and mood. Some even think that certain kinds of insomnia stem from a person’s individual circadian rhythm which favors a biphasic sleep pattern.
If you decide to try the biphasic sleep pattern, your main challenges will probably be of social nature, as the modern world does not easily accommodate anything other than the accepted monophasic sleep pattern. Whether you decide to follow a siesta-based biphasic sleep pattern (like president Kennedy and some other famous people) or split your night-time sleep into two parts, you’re likely to miss on social engagements.
That doesn’t mean, of course, that you can’t try. If you do, keep a few things in mind. First, give it a few weeks, as any new schedule will take you time to adjust. Second, biphasic sleep requires a strict schedule: you can’t just nap whenever you feel like it, consistency and timing is key here. You will have to make sure that you are actually get enough sleep even if it is segmented. Most importantly, remember that everyone’s circadian rhythm is different. Some people are more biologically inclined for monophasic sleep and others for biphasic (or polyphasic) sleep. So you might just see all the benefits that some people report, or you might not. If you don’t, and especially if you feel worse, it’s probably wise to stick to the tried and true monophasic sleep.
In addition, according to Dr Michael Breus, a clinical psychologist and sleep doctor, some groups of people – like those who are prone to depression – are advised against trying the biphasic sleep approach, as any kind of disruption in circadian rhythm can have a significant negative impact on mood disorders.