Using your circadian rhythm, part 2

On average, americans spend 8.7 hours a day sleeping - more than 28 years of their life! What the heck are we doing with that time? It seems excessive; on the other hand, it is clearly not optional. As far as keeping us alive, sleep is right up there with water, we can only go without for a few days before we risk death. For a long time sleep was thought to be passive, but now it is now known that we pass through 5 stages of sleep. They are called, somewhat unimaginatively, stage 1, 2, 3, 4 and REM (Rapid Eye Movement). Through out the night we pass through the successive stages from 1 to 4 and then back to 1 and then into REM. Then we start over with stage 1. These cycles take about 90 minutes.

A typical, 8 hour, nightly cycle

You may want to notice from the chart a few things. The first thing to notice is that REM sleep and Stage 4 (Deep sleep) are emphasized by color. This is because we think we are starting to understand what these stages do, and that they are important. The second thing to notice is that Stage 4 is more prevalent at the beginning of the night and REM sleep becomes more common latter in the night. The third thing to notice is that we spend a lot of time in Stage 2. As far as I know, no-one has any strong theories about what Stage 2 is for, but I think that eventually someone will discover that it is key to our mental health in some way.

Here is where the circadian rhythm comes in. It turns out that the stages of sleep that we go through are linked to our circadian rhythm - NOT to the length of the sleep. That is to say we do not start the same cycle every time that we go to sleep, but our cycle is determined by WHEN we start our sleep. So by napping in the early part of the night, we get a lot of Stage 4 sleep. A morning nap gives a lot of REM sleep, and a nap in the afternoon consists mostly of Stage 2 sleep.

Correlation between

monophasic sleep cycles and

circadian triphasic

It is interesting to note that the triphasic sleep pattern are similar, but more efficient than the monophasic pattern. There is less time moving through intermediate phases in the triphasic, and no intermediate short waking cycles. The triphasic data is a composite from Zeo sleep data. At some point, I would like to be able to start measuring data directly from my sleep cycle.

So on the triphasic sleep pattern, one gets about equal amounts of REM, Stage 2, and Stage 4 sleep. I think this explains why the triphasic schedule is so easy to change to, and has very little "adaptation" time. 

Using your circadian rhythm, part 1

The master planner of sleep and activity is the suprachiasmatic nucleus, also know by as the "body clock". The signals produced by the body clock are referred to collectively as our circadian rhythm. Our body clock is not a natural 24 hour clock, and uses sunlight and darkness to stay in sync with the solar day. The rise of sleep disorder may be linked to the fact that many americans receive less than 10 minutes sunlight a day, and the body clock becomes out of step with the standard day.

The suprachiasmatic nucleus does not use the rods and cones in your eyes, but a third photoreceptor called the melanopsin. This protein detects changes in light intensity - it receives a strong signal when it gets brighter in the morning and darker in the evening. It is also triggered by the changing light of shadows in bright daylight. The contrast with electric light is not high enough, but the difference between bright daylight (100,000 lux) and shadow (1,000 lux) keeps the melanopsin active, and in turn, keeps us alert.

466 nm wavelength light

Melanopsin respond to a narrow bandwidth of light, in the range of 466-477nm, which explains why full-wavelength light therapy has not been very successful. It also explains why it is so easy to feel energized on a day with a bright blue sky and so easy to feel tired on a grey, overcast day.

So the melanopsin act as our day length regulators. Morning daylight signals our body clock to start its active cycle. Sunlight is strong enough to start this effect even with our eyes closed. The suprachiasmatic nucleus releases a number of hormones including serotonin, adrenalin and cortisol. The increase in serotonin helps us to become conscious again after sleep. Adrenalin and cortisol create increased metabolism and body temperature. 

By mid afternoon, the body's metabolism has peaked. There is a drop in cortisol that is apparently the signal for a mid afternoon nap. We are biologically programmed to take a nap during middle of the afternoon, roughly between 1 and 4 pm. We all know that time of day tends to be drowsy, but despite urban myth it is not because of too-warm offices or heavy mid-day meals (although those things certainly exacerbate the phenomenon).

Sleep hormones correlated 

with sleep need and sleep urge.

A surge in cortizol and adrenalin wake us up a short time later, and we have a few hours before the setting sun triggers our melanopsin and the body clock begins to convert the serotonin into melatonin, which in turn lowers our body temperature and creating lethargy. A few hours later, the melatonin slows down and it becomes more difficult to fall asleep. 

As far as we know, it is not possible to change our hormone production through will power. Therefor, we should use our base circadian rhythm to our advantage when we are designing a poly-phasic sleep system. The triphasic sleep schedule maps to the circadian system well in the following ways:

1) First nap at 1:30pm takes advantage of the mid-afternoon drowsiness to get a nice 80-90 minute nap.

2) The second nap at 10:30 takes advantage of the the increase in melatonin, body temperature drop, and serotonin drop to speed us to sleep.

3) The third nap at 5:00am takes advantage of the daily accumulated sleep debt to aid us going to sleep despite the lower melatonin levels. Upon awakening, the melanopsin resets our body clock, re-syncing us to the solar day.

By using your natural circadian rhythm, you have higher sleep efficiency (time and quality of sleep / number of hours in bed). You fall asleep faster, your naps are more restful, and you awake to a natural surge allowing you to start your day refreshed and alert.

Tomorrow we will talk about an added benefit of placing your naps on this rhythm.

Is polyphasic sleeping right for you? part 3

The next question that one ought to consider if you are thinking about doing a polyphasic schedule to gain productive hours, is whether you are able to fall asleep quickly. While you save time by cutting out some of the Non-REM sleep, if you have difficulty falling asleep, or if you have an elaborate bed-time ritual, any gains that you make on saving sleep, will be lost in the pre-sleep routine. On the other side of it, your morning routine needs to be efficient as well. The more efficient your sleep schedule, the more efficient your extraneous routines need to be.


For an uberman schedule, where you are sleeping in six 20-minute blocks, for a total of 2 hours of sleep a night. However if it takes you more than 30 minutes to take your nap from the time you switch from productive activity, and more than 30 minutes to resume productive activity when you get going after your nap, then your effective time becomes something like 8 hours, and you have lost nearly all the gains that you have made. I find that it is easy to lose 30 minutes of productive time before a nap. My routine involves using the bathroom, doing dental care, take stuff out of my pockets, check my alarm (if I have set one) and then going to bed. I am luck in that I typically fall asleep in under 5 minutes. So my "pre-nap" routine takes about 15 minutes. However, I ALSO tend not to start a new project within about 30 minutes before a nap, so I lose some productive time there. I figure that on average I lose another 10 minutes. So my nap routine, which is pretty simple and relatively quick eats up 25 minutes three times a day.

Mmmm... Coffee.

My waking routine involves making a pot of coffee, while I do the dishes, and then having a cup while I check my email. I am doing some multi-task items in there, but I would guess that I have about 10 minutes of dedicated "morning" routine. Since did a similar routine once a day when I slept monophasically, versus the three times a day now, I lose a hidden 70 minutes in the combined before and after nap routines. This makes my adjusted "awake/ non-sleep routine" time 18.0 hrs a day vs the monophasic 15.3 hrs a day. Which is only a 18% gain, or an extra 1.25 days a week. Still worth doing, but only if the negative effects are relatively minor.

If you are considering a polyphasic routine, be honest with yourself on how long your sleep-oriented routines are, including the time it takes you to fall asleep. The average time to fall asleep in the US is around 30 minutes, which completely negates any benefits of an Uberman or Everyman schedule, and severely minimizes the benefits of a triphasic cycle.

30 days of polyphasic sleep.

I am still loving my triphasic sleep schedule, and expect to continue on it indefinitely. The three "days" per 24 hour cycle work well for me. I am more productive, and I am having more fun as well. I really enjoy the time that I am awake at night. I have been doing a lot of design work and more cooking. I have been baking bread and making cheese. I have been able to pour considerable amounts of time into my new business, Fiddlehead Homes.

I have been tracking my sleep time carefully over the last two weeks. I am averaging 4.9 hours of sleep. I average about 4.5 hours a night typically, and then, about once a week, I sleep through the night and lose my night "wake" period entirely. So far this has happened the night period after white-water kayaking. Out of the 4 times that I have gone whitewater kayaking or whitewater canoe racing, I have slept through the night 3 times. I am not sure if that is a coincidence or not. It has been pretty well documented that we don't need sleep for our muscles. They are able to repair and build themselves during any sort of low-activity/rest phase. Whitewater kayaking is new for me, so it may be that I am sleeping through the night in order to process the new skills. One theory of sleep is that we process new skills (specifically - motor sequencing and motor adaptation tasks) during Non-REM sleep, which is the part of sleep that my schedule is deficient in. On the other hand, it could also be that the kayaking has nothing to do with my need for the extra sleep, and it is simply a coincidence. It could be that I slowly accumulate sleep debt and need to pay it back, and that the days that I can go kayaking are also days where I don't have anything pressing scheduled for that night. I will have to continue to be consistant about tracking it, and see whether I can come to any conclusion.

Negative effects:

My wife, who was born and raised in Texas, has been enjoying suddenly being the tough one when it comes to the house thermostat. I have become much more sensitive to cold. I have been keeping my home about 5 degrees warmer since I started this experiment, and I often have on an extra layer and have the heat lamp on, when I am at the computer. If I am up and moving around, I don't really seem to have that issue. It is just when I am sitting, sleeping or otherwise inactive.

I have gained about 3 pounds over the last 4 weeks. My weight fluctuates by about 3 lbs per day, so at first it was hard to see that trend, but it is clear now. I will have to watch this very carefully. I have definitely been eating more sweets and fatty food. I am not sure whether that has to do with moving my office out of the bedroom and into the dining area, or because I am burning more calories per day, or is some negative artifact of sleeping less.

I do tend to fade a bit at about 3:30am until about 5:00am, when I begin to become more alert. I am debating about whether to change my schedule a bit to take that into account. I may add in a nap and do a 40 min nap at 3:30 and do a 40 minute nap at 6:00, but that seems a bit clunky.

I have difficulty taking medicine "two times a day". I currently take Loratadine for my allergies, and I am supposed to take them every 12 hours. With a triphasic day, that means that I take them first thing in the "morning", then in the middle of the next "day", and then skip a "day". I almost always get it wrong an skip one or take an extra one. With Loratadine the consequences are minor to the point of not making any difference, but I need to come up with a system for the future, when I will have to take a medication regularly.

Dancing cabaret knights - 

a negative effect of triphasic sleep.

The last negative effect that I have noticed is that I constantly have some song stuck in my head. This has never happened to me before, I used to just have thoughts, dialog, or silence; now I have some little tune playing all the time. My wife says that she always has a tune playing in her head, and I have always been unable to imagine what that could be like. Now I know that it is very slightly irritating. My current tune is "Camelot". Unfortunately, it is not from the musical of the same name, but from "Monty Python's Search for the Holy Grail".

Overall, the positive effects powerfully outweigh the negative, so onward I go.

Is polyphasic sleeping right for you? part 2

Contrary to part 1, there is strong evidence that polyphasic sleeping ought to be more common. In its broad definition, polyphasic sleep is a term that refers to sleeping multiple times during a 24 hour period. Sleeping 3 times a day is called triphasic, Sleeping 2 times a day is refered to as biphasic, and sleeping once a day is termed monophasic. Polyphasic sleeping does not necessarily connote sleep optimization in order to stay awake for more hours a day, although that is a very common usage.

The majority of americans try to keep a monophasic schedule. Monophasic schedules are so common that any other schedule is often thought to be not only an aboration, but a pathology. There is a pervasive belief that monophasic sleep is somehow more natural, or even more moral. But, in fact, the western idea of sleep seems to be the exception, with its no-contact, sensory isolated, monophasic sleeping.

Hunter gather societies, such as the !Kung and the Efe are fluid, poly-phasic sleepers. They sleep when they are tired, whether it is day or night and independently of when others are sleeping. Much of the world sleep most the night, but have a nap during the day, making them biphasic sleepers. Egyptians, and the spanish fall into this group. Some people argue that the natural human rhythm of sleep is triphasic, with an interrupted night sleep and a nap during the day. Most people in the world sleep on a biphasic or triphasic schedule. Even in the US, the research has shown many benefits of "power naps" including better memory, mental health, and even a decrease in heart disease.

Furthermore, nearly 33% of americans suffer from sleep disorders. Might it be that 33% of us are not natural monophasic sleepers, and that having difficulty with monophasic sleep ought not be a pathology? It is not like we are born sleeping through the night. That has to be taught.

A natural polyphasic sleeper

There is a fair body of evidence that "sleeping through the night" is a myth for adults as well. If you have a sleep disorder, or you have trouble sleeping all night, consider trying a polyphasic schedule. Don't necessarily try to restrict the total amount of time that you sleep, be open to sleeping as much or as little as you need. Go to bed a few hours earlier, take a nap, get up and do whatever routine fits your life, take another nap, and get up at your usual time. For the 50 million americans that suffer from insomnia, what have you got to lose?

Is polyphasic sleeping right for you? part 1

The short answer is: probably not.

If you are thinking about trying a polyphasic schedule, the first question you should be asking yourself is what are you going to do with all the extra time? Even under a relatively non-extreme schedule, like mine, you are gaining the equivalent of two extra days a week.

Except, it is not really equivalent. By definition, any time that you "gain" must be happening when everyone else is asleep. Which means that it is happening at night. In the dark. When others are trying to sleep. This significantly limits the sort of activities that can fill the "gained" time. Unless you live in a true 24-hr city, you can not run errands. You can not make business calls or have meetings. You also can not do anything social. Your monophasic friends are not going to appreciate a 3am phone call to get together and hang. If you live with someone else, you will need to choose activities that are quiet. Additionally you can not do anything that requires daylight, like weeding the garden or white-water kayaking. Surprisingly, even web-surfing is oddly limited. There are no updates during the night on my favorite websites. There are no facebook posts or emails.

White-water kayaking.

Daylight recommended.

So what CAN you do with the extra time? There seem to be two options. Either you are playing World of Warcraft (in which case your rigid sleep schedule is going to irritate your group), or you are doing something creative. Not surprisingly, fighting boredom is one of the most common complaints that come up on polyphasic blogs. Everyone can use a little extra time, but most people are not going to be able to fill an extra 1500 hours a year.

For most people, stargazing 

can only take up so much time.

If you are primarily a social person, then you will not experience any real gains by having extra waking time. If you are a creative person, are your (quiet) creative projects really going to fill 1500 hrs a year, or do you have a couple of 40-hr type projects? I find that it is easier to wake up and get going if I am excited about a current project. If you try polyphasic sleeping and find that you are fighting boredom, then go to sleep! What is the point of having a rigid schedule to give yourself something that you don't use?

Note to self: Don't change the schedule.

I crashed hard about 4:30am this morning, a slightly delayed after effect of meeting some friends for lunch at 1:00. I did not get to my afternoon nap until 3:30, which is 2 hours later than it is scheduled. I slept for about 1:45 minutes, which is fine. My sleep was good and I awoke refreshed and sharp. Now I had a phone get-together scheduled with another friend at 9:00pm, but he had to push it back until 11:00. I thought this would probably be no problem since I was already 2 hrs behind on the day. However, at 10:30 - my usual nap time - I was starting to fade, so I thought that I would try taking a short nap before I talked to my friend. I seemly awoke on my own, but i must have been woken up by my friend calling, as he was on the phone when I checked the time. I keep the ringer on vibrate, so it is relatively subtle. It was 11:00, so I had slept for 1/2 hr. I talked to him, had my coffee and started my day. I wondered if the longer sleep this afternoon and the shorter sleep this evening would average out such that my schedule would be unaffected.

How did I not see this coming?

Now, I have to admit, it hasn't worked that way on other days that I have tried altering my schedule, and today was no different. At 3:50, a full 1 1/2 hrs before I normally sleep, I was suddenly and deeply tired. I lay down on the couch and immedately went to sleep, waking at 6:45, which is basically my regular time. I feel a little bit groggy this morning. We shall see if I can right my schedule without another extended nap.

Most people think that the rigidity of the poly-phasic sleep schedule is a huge downside, and to some extent, this is true. However, it is not like mono-phasic sleepers have a flexible schedule. My friend that I was on the phone with eventually had to call it a night and head for bed. It was only about 1/2 hr past his usual bedtime, and he was worried about the consequences for himself in the morning. I think that the real downside to the poly-phasic schedule is not that it is rigid, but that it does not align with socially excepted norms. I would think that in countries where siestas are more common, that one might be able to do a tri-phasic sleep schedule with no social consequences at all.

Short sleepers

Apparently there are some individuals who only need 3-4 hours a sleep a night naturally and do not suffer from sleep deprivation. They are called "short sleepers", and an oft-quoted statistic says that they are 1%-3% of the population. That percentage seems high to me, since a scientist who studies short sleepers has only found 20 individuals so far. I have been deeply enjoying my extra time that I have acquired by changing my sleeping schedule and gaining an extra 3-4 hours of awake time a day. However, it is not without some penalties. I do have to be fairly careful to keep my schedule consistent, and it sometimes meshes poorly with other activities. It would be pretty nice to sleep as little as 3 hours mono-phasically. These "short sleepers" have a mutation on a gene known as hDEC2. Well, there is another gene lottery that I lost; I have to compensate for it with creativity and hacks. More information on short sleeper can be found in this Wall Street Journal article. 

Not a short sleeper.

Perhaps, not surprisingly, many people that claim to be short sleepers, are in fact, simply depriving themselves of sleep. Symptoms of severe sleep deprivation include: confusion, memory lapses, hallucinations, headaches, eye bags, increased blood pressure, irritability, ADHD-like symptoms, and increased risk of diabetes. That last one is a little odd since coffee consumption has been shown to decrease the risk of diabetes. I know from previous experience that one of my early symptoms of sleep deprivation is that I lose precision in tracking objects with my eyes, and I will get multiple after-images when there is a bright light, or I will be unable to focus on text. My eyes seem to drift across the page, without reading the material. So glad that I am not in college anymore. 

What about the symptoms of non-severe sleep deprivation? Turns out that there is a very easy way to diagnose that. You feel tired or sleepy. That is all there is to it. One of the disqualifications of people that claim to be short sleepers, but in reality are sleep deprived, is that when they have a break in their schedule - a vacation or a weekend, they will tend to sleep in. It is one of the reasons that I try not to use an alarm during this polyphasic sleep experiment - because the point is not to try to get by while sleeping less per se, it is to try to get all the sleep I need more efficiently. 

Reset

Last night thought I might be feeling the effects of some sleep debt. I went to bed at my usual 10:30pm and did not set my alarm, so that I would get whatever sleep I needed. I awoke a couple times in the night, but fell back asleep without any problem, finally getting up at 7:00am, for a total of 8 1/2 hours of sleep that night. Today, all seems back to normal with a 1:15 hr nap this afternoon and a 1:20 hr nap this evening. I have been alert and productive again.

I am still unsure whether the sleep debt came about primarily from accumulated lack of sleep over the last 2 weeks, or whether it had more to do with my schedule becoming erratic. I will be trying to keep my schedule regular for this next two week period to see if I accumulate more debt. If so, then it looks as though I may be able to repay the sleep debt with a single 8 hr sleep/fortnight, which would increase my average sleep from 4:25 minutes to just under 5 hrs a night. Not as good, but not that bad. 

Some signs of sleep debt.

The last day and a half, I have not been waking up before my alarm. I have had reluctance to get out of bed and I have been feeling tired before my nap times. I think that I have some sleep debt. I have been taking my Epworth Sleepiness Scale test since the experimented started. Monophasic sleep was a "3" and most of the experiment thus far my ESS score has been a "1". However, in the last couple days, it has gone up to a "6". The average US male score is "4 1/2." So, I am not going to use an alarm for my evening "nap" with the expectation of sleeping most the night. I will continue taking my afternoon nap. I am curious to see whether the sleep debt will be easily repaid, and I can continue on what has become my normal schedule, or whether this will be the de facto end of the experiment. I think that it is a little odd that the first signs of sleep debt took more than two weeks to show up. I wonder if it has to do with messing with my schedule on Saturday, and then again on Monday or whether it is chronic to the schedule itself. Only time will tell.

Day 15 - had to push back my afternoon nap

A friend had some car problems, and that lead to me pushing my nap back until 4:00. I did not want to nap in the car, because I was wearing my wetsuit and had been in 32 degree water. I was warm enough, but a long way from comfortable, and I knew that I would not be able to stay warm if I slept. My body temperature has always dropped when I sleep, and that effect has gotten more pronounced. I crashed out at 4:00 and slept until 5:15. I woke up alert and refreshed, but as I am approaching my evening nap, even though I have only been awake for 4 hours, I will be ready to hit the bed.

I am trying out sleeping 1:15 instead of 1:30, because I have been waking up dreaming. If 1:15 does not work consistently, I will try 1:45. There is a sleep monitor app for the i-phone. That would be really nice to have so that I could chart my cycles. 

Day 14 - two week mark

It is hard to believe that I have only been doing this for 2 weeks. It has been so easy and natural. My notes show that over the last 2 weeks I have slept a total of 62.3 hrs. or 4.45 hrs / night.  The US average for adults is 8.7 hrs / night. So that come out to be gain of 49% respectively. To put this in perspective, that means that gives me an extra 101 waking days per year. Every 3.6 years, I will gain another entire year's worth of time. Crazy! 

Day 13 - Delicious luxury of sleeping in.

On Saturday, I competed in the Passy Canoe race. I pushed hard and it was especially grueling. We pulled our canoe out of the water at 12:30, and by the time the award ceremony was over, and the canoe was loaded, it was 2:30 - well past my afternoon nap. Because I had errands to run, I went ahead and napped in the car, which I have successfully done before. I slept about 40 minutes, and woke reasonably refreshed, but not feeling mentally sharp. I had friends over that evening, and got to bed at 11:00. I did not set my alarm, with the expectation that I would sleep in somewhat. I woke at 2:30, did a few chores and went back to bed. When I woke, I was feeling quite sore from the previous days race. My wife was already up, and I had no idea what the time was. I felt as though I had slept in until 1 in the afternoon, which used to be something that I would do a couple times a month. Instead it was my usual wake-up time of 7:00am.

I think that it is interesting that I got that same luxurious feeling of sleeping in till noon (or later), with only a "normal" night's sleep. While there were some things that I wanted to get done during my night, I am glad that I went ahead and slept. I took my usual afternoon nap that day of 1 1/2 hours, and my evening nap was also 1 1/2 hours, and I feel alert and refreshed. I seem to be (back?) on my tri-phasic sleep schedule.

Because I missed my night wake cycle yesterday the weekend seemed to happen VERY fast. I have become completely addicted to having the night all to myself. It is really nice "down" time. It is quiet and peaceful. I have to plan on what I can get done during daylight hours. Yardwork, errands, social time, and business meeting and calls all have to happen during the day. This leaves the night for chores, cooking, writing, relaxing, and design work. It makes the 3 cycle pace of my day interesting. It  makes the night feel like a weekend - even on the actual weekends. 

Day 11 - Waking in the middle of my naps.

There has been a slight change in my nap pattern. I am not very tired when I get to my scheduled naps. I have been waking up at the hour mark, checking my clock and then snoozing for the rest of the nap. I am not sure that this snoozing bit is doing me any good, or whether it means that I have been trying to get up in  the middle of a REM cycle. I have been waking up from the snooze with my alarm clock, but I have only been getting up about 10 minutes after the initial alarm. I am clearly being woken during vivid dreams and I have that type of grogginess that I have always associated with sleeping in too long. It seems weird to me, but I think that less sleep will do me better. I am going to go ahead and do one more 1 1/2 hour cycle and then try switching to getting up when I wake up the first time, no matter how short that nap might be.