Biphasic Sleep: All You Need To Know

In this world where there are billions of people, it is normal to have a varying pattern of sleep from the next person. Biphasic sleep is a very common pattern of sleep- probably more common than you may think. This article will say all you need to know about biphasic sleep. 

What Is Biphasic Sleep?

Biphasic sleep is sleeping in two phases or sessions within a 24 hour period. This means the body goes through the process of sleep at two different times within a day.

Why Does Biphasic Sleep Happen?

When we were kids, biphasic sleep happened because we were forced to sleep! At that time we had to take naps around mid-day because our parents needed a break from our hyperactivity. Now, if you are like me, you take afternoon naps because your body and brain demand it.

 It gets to a certain period in the afternoon time when your brain begins to demand rest, your productivity and concentration drops and you feel really tired. In other words, biphasic sleep happens because that’s how your body is wired.

For some people, biphasic sleep happens because they have conditioned themselves that way. By this, I mean that they have become used to getting adequate sleep in two sessions a day.


What Are The Types Of Biphasic Sleep?

Biphasic sleep can happen in two forms

1. Both sessions can occur at night.

You most likely know someone who goes to bed early, wakes up in the middle of the night for a few hours and then returns to sleep till morning.

The person goes through two different sleep cycles separated by a few hours where they are completely awake.  For example, the person goes to sleep around 7.30 p.m. wakes up at 11.30 p.m., then goes back to sleep at 3 a.m. until 6.30 a.m.

2. One phase at night and another in the day.

This is the kind we had as kids. It is also the more common type in adults. The person sleeps a couple of hours at night and then takes a power nap in the daytime. The longer session is usually at night. An example would be going to sleep at 12 midnight, waking up at 6 a.m. and then taking a one hour nap after lunch from 1 to 2 p.m.

For both types, the total number of hours of sleep is usually six-eight hours. This is still the recommended daily amount of sleep for an adult.

Is It Normal To Have Biphasic Sleep?

Biphasic sleep is a sleep pattern usually set up by the body itself to help it get the rest and rejuvenation it needs. So, yes! It is perfectly normal to be a biphasic sleeper.

In the past, before the industrial era, the normal sleep pattern was biphasic. It was when the industrial move came that people were forced to sleep in one block so as to work more.  If left to itself, it is thought that the body (in most instances) would revert to biphasic sleep.

Some people have been known to train their bodies to run on biphasic sleep because a few studies have shown that it has a lot of benefits – which we would talk about now.

Does Biphasic Sleep Help Me?

Although only a few studies have been done on this sleep pattern, researchers have shown that biphasic sleepers enjoy a couple of benefits. Some of them are explained below.

  •  It improves cognitive function. Cognitive functions are those things the brain does that lead to gaining knowledge and information. These processes include learning, memory, attention, reasoning, and language. It is said that biphasic sleepers have all these processes improved so it’s easier for them to increase knowledge.  Maybe this is why we had to nap when we were younger!


  •  It improves productivity. Biphasic sleep is thought to boost alertness because the body is better rested. When the boosted alertness is added to increased cognitive capabilities as above, the result is an increase in productivity. Also, there is no burn-out attached to the increase in productivity.


  •  It reduces stress. It is thought that sleeping in two phases per day may cause ‘de-stressing’ based on the similarity to taking a power nap. Power naps are thought to reduce stress, improve learning and increase mental alertness.


  • It allows for flexibility. Using two blocks of time for sleep may allow you to juggle all your life responsibilities such as family, career, hobbies, and business. A classic example would be a new mother. She most likely has to complete her sleep in more than one block for her to maintain her sanity.

Can Biphasic Sleep Harm Me?

Biphasic sleep has not been medically shown to be harmful. However, very little studies have been done on the subject. Historically, people used to sleep in a biphasic pattern and there seems to be no record of a harmful effect.


That being said, there might be downsides to biphasic sleep in your social or professional life. If you are a biphasic sleeper of the both-phases-at-night variety, you might not have much of a night life; simply because you have to go to bed early. It’s pretty difficult to have a full, adult, social life with a bed time of 8 p.m.

On the other hand, the one- at- night- one- in -the- day variety might have problems with their boss if they have to take naps in the middle of the day. Even if you were the boss, it may not be good practice to take regular afternoon naps while your employees work for you.

Although both types of biphasic sleep have downsides, there is no known medical adverse effect.

Are There Other Sleep Patterns?

Generally, there are three types of sleep pattern. The monophasic sleep pattern, biphasic sleep pattern and polyphasic sleep pattern.

Monophasic sleep

Monophasic sleep is sleeping in one session per day. For example, sleeping at 11 p.m. to wake up at 5.45 a.m. and that’s it for the day. This is the pattern of sleep you find in most career people. They really don’t have the time or freedom to sleep in two or more blocks.

Like I said earlier, this sleep pattern began in the industrial era so people could work and become more productive. Some people say that this pattern is not natural and it only occurs because the body has been conditioned that way by current society trends.

If you sleep in this pattern and you are not a nine- to- five worker – there is nothing wrong with you! People are wired differently. You might just be a natural monophasic sleeper. As long as you get your recommended ‘dosage’ of sleep (7- 8 hours), then you are probably fine.   

Polyphasic sleep

You have probably figured out by now that polyphasic sleep means sleeping in more than two blocks per day. For example, a person can sleep from 8.30 p.m. to 11.30p.m., stay awake until 4 a.m., and then sleep till 6.30 a.m. after which they take a power nap between 1 and 2 p.m. in the afternoon.    

This sleep pattern can be more than 3 blocks – an example of this is what we see in babies. Sleeping in little chunks of time may be natural for some people and impossible for some (like the career people).

No matter the type of sleep pattern you practice, what is important is that it suits you. You must be getting adequate rest that is refreshing and rejuvenating to the body.   

What Type Of Sleep Pattern Is Best For Me?

There is no particular sleep pattern that is superior. Scientists don’t know what causes the body to pick a particular pattern. What they do know, is that some people need 7-8 hours of straight sleep while others need their sleep broken up into two or more sessions during the day.

Some researchers believe that the pattern best suited to us might be related to our genes. As it’s expensive to go through genetic testing to determine which sleep pattern is encoded in your genes (let’s not talk about the fact that it’s highly unnecessary!), the best way to tell your ideal pattern is by watching your body.

Watching your body is the best way to decipher if your current sleep pattern is working for you. Are you well rested? Is your concentration good? Do you remember things easily? Is your productivity rating high? Chances are that you are doing well in the sleep department. If you are stressed, fatigued, have poor concentration and low productivity, your sleep pattern may not be suited to you.

You may be one of the lucky few who seems to have hit jackpot on their ideal sleep pattern or you may be one of the many forced into a less than an ideal pattern.  Either way, you can try out new patterns of sleep to find which one works best for your body and your schedule.  You may also simply want to reap the benefits of biphasic sleep outlined above.

I Want To Try Biphasic Sleep, How Do I Do This?

The first point of call is what is wrong with your current sleep pattern? If there is nothing wrong and you are doing well with it, then why change? It isn’t a problem to want to change and try something new, but remember that it’s best to let your body tell you what it needs. You also have to consider if your current schedule permits biphasic sleep.

These are some of the things you need to think about before adjusting your sleep pattern.

However, if you aren’t satisfied with your current sleep pattern, your schedule has recently changed or you want to reap the benefits of biphasic sleep; it is possible to change your sleep pattern. But first, a few warnings:

  • Changing your sleep pattern may take its toll on you. You may feel more tired, groggy and cranky until you adjust to the new pattern.
  • It involves a bit of trial and error to find what works best for you. There is no ‘one size fits all’ for sleep, so you have to keep trying to find ‘the one’ for you.
  • There isn’t that much information on the subject so biphasic sleep may be bad for you eventually, we just don’t have any proof that it is. However, the little research done gives a more positive outlook.
  • Quit if you notice that it doesn’t work for you. Return to what your body was set to do in the first place.

Now that we have gotten the disclaimer out of the way, let’s get down to changing your sleep pattern to the biphasic type.


You do know we aren’t going to let you change your sleep pattern without your doctor’s input first, right? So please consult with your doctor before changing your pattern as you may have some medical history that precludes you from this process of change.


Pick what type of biphasic sleep you want. Three factors to help you decide are

  1.          Your schedule
  2.          When you normally feel sleepy
  3.          If you wake up in the middle of the night

If you are a nine-to-five worker, then you probably have to sleep both blocks at night. Or if your job permits, you could take a 30-minute nap during the lunch break. If you usually feel sleepy around mid-day, then it might help to plan one block around that time. If you wake up for a few hours in the middle of the night you may want to pick the both-sessions-at-night variety.


Stick to your chosen plan and be consistent. Create a fixed schedule so your body can quickly pick up the rhythm and adjust itself. Adopting an erratic sleep schedule while undergoing a change will most definitely produce adverse effects. These effects include decreased productivity, grogginess, loss of concentration and being cranky.


Maintain good sleep hygiene during whatever sleep pattern you have chosen. This includes reducing your exposure to artificial light in the hours before your scheduled sleep. Sources of artificial light include television, laptop, computer, and smart phone screens. This may be difficult in our current social media society, but remember that you have an objective. Exposing yourself to artificial light disrupts your desire for sleep and causes your body to wind up rather than down.

This is also important if you choose to sleep both blocks at night. If you use these devices in the middle of the night, it might make it difficult to get to your second session of sleep.


Remember the warnings! If the pattern you have chosen doesn’t work well for you – please QUIT IT!

How Do I Know Biphasic Sleep Is Working For Me?

Once again, the best determinant to know if you have chosen an ideal sleep pattern is your body. If you are well rested, productive, not stressed and happy, you have probably got it right.


Biphasic sleep is said to be the natural form of sleep for adults according to history. However, not everyone can run on sleeping in two blocks and science has proven that. Whatever sleep pattern you have chosen, the important thing is that it works for you.

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Oyinkansola Kolawole, MD

Dr. Oyinkan Ogundimu is a graduate of medicine and surgery. She migrated to the United States to pursue her dream of caring for patients, her passion in life is to help people in all the ways she can including breaking down difficult to understand medical facts into simple and fun bits of information.
Oyinkansola Kolawole, MD