That one nap you take after a heavy meal. Or the one after school or college, where you just want to sleep for an hour before you do school work? Or just simply have a nap in the afternoons because they help you? How satisfying they sound! Actually. Very appealing. To jump into the bed, after turning on the air con and curling up in the blanket…. But, wait, have you ever wondered why your body works that way? Why can’t you sleep ‘enough in one stretch’? Why are you sleeping twice a day? It’s called Biphasic sleep.
What is biphasic sleep?
Biphasic sleep (or diphasic, bifurcated, or bimodal sleep) is the practice of sleeping during two periods over the course of 24 hours. These can be two periods of sleep with a short time of being awake in between them during the nights, or the much more common medium timed nap in the afternoon and a longer sleep at night.
But what your parents, annoying ‘snack-stealing-while-you’re napping’ sibling or that over-productive friend would be following is a monophasic sleep pattern, where the person sleeps for one extended period of time, usually during the night, but sometimes during the day.
But hey, it’s not wrong to have your afternoon siestas. In fact, many have reported increased productivity and quality of life after adopting this two-phase sleep pattern. Of course, everyone’s sleep needs are different: some may need eight hours of sleep at a stretch, while others may only need a few short hours twice a day. But biphasic sleep remains harmless, and can help cope with fatigue and stress.
Biphasic sleep also differs from polyphasic sleep, which involves sleeping for more than two sessions in a 24-hour period. Like that sleeping pattern you would’ve developed while you were cramming for exams? Or those crazy intelligent cousins preparing for competitive exams? You’d often see people like them taking naps ranging from 20-30 minutes after a session of studying. It is proven that in this way, the brain works in a more efficient way and that works wonders.
How long have been been doing it?
From medical texts to court records and diaries and even in African and South American tribes, bimodal sleeps are referred to as ‘first’ and ‘second’ sleep. Researches conducted by anthropologists have found evidence that, during pre-industrial Europe, biphasic sleeping was considered a common practice. Sleep time was mostly decided by work schedule, unlike the one now that’s decided by bedtime.
Historian Roger Ekirch discovered that the concept of first and second sleep began to vanish during the late 17th century. This is believed to have started from the upper classes in Northern Europe.
Typical biphasic sleep schedules
Different cultures have maintained a variety of biphasic sleep schedules throughout history, and some people continue these sleep patterns today. There are several common biphasic patterns worldwide.
Siesta is when someone sleeps for a short duration at night and takes long naps during the day. This practice started in the Mediterranean region. It is still a common practice in Spain, Italy and in Middle Eastern countries.
This is probably the most common form of two-phase sleep: longer sleep at night, shorter naps in the afternoon. This kind is practiced worldwide. But naptime doesn’t mean you have to sleep less at night.
Despite getting mixed results, biphasic sleep improves your cognitive performance up to some extent, improves your quality of life and gives you a flexible sleep schedule. To find the schedule that works for you, use trial and error. Your bimodal sleep pattern will depend not only on which times you can afford to rest during, but also on what you’re trying to achieve by following this pattern.