Biphasic Sleep Patterns
Have you ever wondered why we sleep for eight hours straight? Most of us typically observe what is termed a monophasic sleep pattern. But there are other sleep patterns including polyphasic and biphasic patterns. So what is polyphasic and biphasic sleep?
Polyphasic and biphasic sleep are patterns of sleeping that break up the typical eight hour monophasic sleeping period into two or more distinct blocks. Hence, the prefix poly, meaning multi and bi which means two.
If we look at the animal kingdom, animals typically have a polyphasic sleeping pattern. For example, cats take naps several times a day, and they’re usually quite brief. Dogs also sleep several times a day. In fact, we ourselves come into this world on a polyphasic sleep schedule. Newborns and infants sleep in multiple cycles.
A newborn baby sleeps quite a bit and in blocks, which is why they wake us up several times a night. This means that polyphasic sleep cycles are the norm and completely natural phenomena. Even toddlers take naps.
So how did we get onto an eight hour monophasic sleeping pattern? What an interesting looking question. To answer it, we take a look back into history.
The History of Biphasic Sleep
Up until the late 17th Century, it was normal to sleep in segments. Most people would go to sleep for about four hours. When they awoke, they usually wouldn't get out of bed.
Instead, they would read quietly, or enjoy intimate time with their spouse. They would then go back to sleep for about 2 to 4 hours.
Over the course of the next 200 years, the idea of segmented sleep had all but disappeared. Historians, such as Roger Ekirch of Virginia Polytechnic Institute and State University believed the advent of street lamps and their improvements led to more night life.
Unfortunately, this also meant more thieves and crime. Those in the upper class didn’t want to go out among the people of ill repute, and there was no other worthy reason to stay up all night. So, they slept instead.
By the 1920s, monophasic sleep, our typical eight hour pattern, became commonplace.
However, Ekirch believes this might be the reason many people have insomnia. Many people wake up in the middle of the night and panic. They think there is something wrong with them, as most of us would.
Millions of dollars are spent on sleeping pills in an effort to conform to the monophasic sleep pattern. But, these people with “insomnia” may just be doing what Mother Nature intended.
Hours of Sleep for Animals
Average Total Sleep Time Per Day
The Sleep Cycle
The average sleep cycle is about 90 minutes long, but it can range from 80 to 110 minutes in length. The cycle has two main categories which include REM (rapid eye movement) and non-REM. These two categories are further broken down into the following five stages:
Interesting Sleep Facts
- Thomas Edison thought sleep was a waste of time, and practiced biphasic sleep patterns.
- Winston Churchill also practiced this sleep pattern as did Napoleon and Thomas Jefferson.
Stage One: Light Sleep
This stage can really be further broken down into two sub-stages. The first part of this stage is when most people suffer from myoclonic twitching (erratic muscle jerks), and muscle activity slows down dramatically. Some of us have more pronounced myoclonic jerks than others.
Hypnagogic hallucinations are also a part of this phase. These are vivid sensations of things such as falling (which typically leads to a rather powerful myoclonic jerk), or someone calling your name. Brain waves go from beta to alpha.
The second part of this stage is the “twilight” like time when we’re half asleep. If someone wakes you up during this time, you’ll most likely say you weren’t asleep. Brain waves go from alpha to theta. The whole stage lasts about ten minutes.
Stage Two: True Sleep
This stage is about 20 minutes in length. In this stage, the heart and breathing rates start to slow down.
Body temperature also starts to drop, and the brain produces what is called sleep spindle waves, which also occur in the transition between stages one and two.
Sleep spindles are the process of refreshing our memories and alternate with K complexes (large waves that occur in response to environmental stimuli such as noises in the bedroom).
Interesting Sleep Facts
Staying awake for 17 hours straight will decrease our brain’s functional capacity down to the equivalent of someone with a blood alcohol level of .05%. The legal limit is .08%. Pretty intoxicating, isn’t it?
Stage Three: Transitional Stage
This is the transitional stage into deep sleep, and delta brain waves start to develop. Your breathing and heart rates are at their slowest in this stage.
Stage Four: Deep Sleep
Also called delta sleep (for the delta waves produced), this stage involves rhythmic breathing, and limited muscle movement.
Episodes of sleepwalking or night terrors typically appear at the end of this stage. This is also when we feel groggy and sluggish if we are awakened. Stage four is about 30 minutes long.
Stage Five: Dream Sleep
This is the dream sleep that involves the rapid eye movement for which the stage is named. Interestingly, voluntary muscles become paralyzed, but brain activity, respiration and blood pressure increase.
After REM sleep, we reverse back through the cycle going from stage 3 into stage two again, and then the cycle repeats itself.
The Sleep Cycle and Biphasic Sleep
It’s important to understand the sleep cycle so that you can schedule biphasic sleep segments correctly.
Since the typical cycle is 90 minutes, any segments of sleep should be multiples of 90 minutes. You can do this any way you want to do it.
For example, I prefer to have a core sleep segment that lasts approximately 4.5 hours and a “nap” that lasts about 1.5 hours. Some biphasic sleepers have a core segment that lasts 3 hours. It just depends on the individual.
Interesting Sleep Facts
Research has shown that people who are deprived of sleep have a more difficult time reacting to changing situations and make irrational judgment calls. In fact, many international disasters have been attributed to a sleep deprivation including the Exxon Valdez Oil Spill and the Challenger Explosion.
The main reason for making sure your sleep segments are multiples of 90 minutes (or around there depending on your needs) is because during stage two of the cycle the brain resets its sodium and potassium levels.
After long periods of sustained beta waves, otherwise known as being awake, the brain’s sodium/potassium levels are all out of whack. The sleep cycle resets these levels which alleviates the foggy, tired feeling.
The Benefits of Biphasic Sleep
There are many benefits to biphasic sleep patterns. Most notably is the two hours of free time gained. That’s an extra 14 hours a week.
As a stay at home mom who also works part time, those extra hours are put to good use. I can get in my workout, all my chores, some homeschooling and writing all in one day!
Another of benefit of biphasic sleep is how it affects chronic pain. For people who suffer with chronic pain on a daily basis, waking up after an eight hour sleep segment can be extremely painful. Muscles feel stiff and getting out of bed can be very difficult.
But with biphasic sleep, the muscles are less likely to become stiff and painful because the body is in one position for a shorter period of time.
Many people suffer from a fog-like state which is usually the result of waking during the REM stage of sleep.
Biphasic sleep allows you to time your sleep perfectly so that you wake up after your REM stage has finished. This eliminates the chronic fatigue caused by waking up during REM.
Implementing a Biphasic Sleep Pattern
There are many different factors to consider when scheduling your attempt at biphasic sleep.
For example, you may lose time with your spouse because inevitably there will be a time when your spouse is awake, and you are asleep and vice versa.
Another thing to consider is children. You’ll have to schedule your core sleep and nap at times when your child is either asleep, or at school. Ideally, if you have younger children, your nap could be at the same time they take theirs.
With all that said, implementing biphasic sleep isn’t difficult, and creating a schedule can help keep you on track. However, most people are tired during the first week. The sensation is similar to what you would feel with jet lag.
If you find, however, that you need more than the six hours a biphasic sleep schedule will provide, you can add a third one and a half hour "nap," which will give you a total of seven hours. This may help alleviate the "jet lag" sensation initially and you can eventually cut out the third nap once you have gotten yourself into a routine.
With biphasic sleep, I can get my workout in at about 04:00 am, while my husband and daughter are asleep and before I go to work. Since it’s so early, it’s done and out of the way.
After I get home from work, I take my 1.5 hour nap and then have the rest of the night to work on writing projects, blogs and other work I need to get done. Biphasic sleep has dramatically improved my productivity and my mental clarity.
It's also affected the amount of pain I have on a daily basis. With a neck injury and osteoarthritis, sleeping for eight hours straight leaves my neck stiff and painful in the morning. I also usually wake to feelings of numbness in my hands and fingers.
Since my longest segment is 4.5 hours, I wake up feeling refreshed, with no stiffness and relatively little pain. I have yet to feel any numbness during a biphasic sleep segment.
Questions & Answers
© 2012 Melissa Flagg OSC