Glen Rhodes

Glen Rhodes

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The Power of the Sleep Cycle

Ok, I’ve been talking to people for a long time about the fact that you can get by on 6 or even 4.5 hours of sleep per day without question. The secret is NOT the amount of sleep, but rather the number itself; a multiple of 90 minutes will change your life. One thing I should mention, is that because we are analog beings, and not computers, that which could be 90 minutes for some people, might be 80 minutes for another, or 100 minutes for another; you will eventually learn the length of your sleep cycle by watching the times you naturally wake up and turn over, make a mental note of the time / interval.  But assuming that 90 minutes is the average, these are the best lengths of sleep that will not make you feel groggy. The worst thing to do is wake up in the middle of a sleep cycle.

1.5 hours
3 hours
4.5 hours
6 hours
7.5 hours

Those are the sleep quantities that you should aim to get, and those are what your body will naturally take, removing the alarm clock. Guaranteed. Go to sleep without an alarm clock, and watch what times you naturally wake up at. It will be a multiple of around 90 minutes from when you first went to bed. This 90 minutes is known as a sleep cycle, and it’s how I try to live my life.

Typically, I sleep 3 hours a night, and nap for 90 minutes in the evening. That’s a total of 4.5 hours, and I am always alert, always awake and always feel rested and refreshed.  Read on for more details…

“A group of Harvard scientists trained volunteers  to perform a visual task that required them to  learn how to recognize certain patterns as they  flashed quickly on the computer screen. When  the subjects were tested 10 hours later, those  who had taken a 90-minute nap did much better  than those who didn’t nap. In fact, they did as  well as people who got a full night’s sleep in a  previous study”  –

Here’s something from the Center for Applied Cognitive Studies (

“Studies show that the length of sleep is not what causes us to be refreshed upon waking. The key factor is the number of complete sleep cycles we enjoy. Each sleep cycle contains five distinct phases, which exhibit different brain- wave patterns. For our purposes, it suffices to say that one sleep cycle lasts an average of 90 minutes: 65 minutes of normal, or non-REM (rapid eye movement), sleep; 20 minutes of REM sleep (in which we dream); and a final 5 minutes of non-REM sleep. The REM sleep phases are shorter during earlier cycles (less than 20 minutes) and longer during later ones (more than 20 minutes). If we were to sleep completely naturally, with no alarm clocks or other sleep disturbances, we would wake up, on the average, after a multiple of 90 minutes–for example, after 4 1/2 hours, 6 hours, 7 1/2 hours, or 9 hours, but not after 7 or 8 hours, which are not multiples of 90 minutes. In the period between cycles we are not actually sleeping: it is a sort of twilight zone from which, if we are not disturbed (by light, cold, a full bladder, noise), we move into another 90-minute cycle. A person who sleeps only four cycles (6 hours) will feel more rested than someone who has slept for 8 to 10 hours but who has not been allowed to complete any one cycle because of being awakened before it was completed…. “

It explains why, when I get 8 hours of sleep I feel tired and groggy, or when I get 4 hour of sleep, I can barely wake up. As human beings, we should know about this fact, as everyone always says “get your 8 hours”. Yet some people fare better than others. Why is that? Probably because the more rested people are actually getting closer to 7.5, or 9 hours, while the 8 hour folk feel constantly unrested.

It is said that many of the most productive people in history have understood and practiced this. Leonardo Da Vinci, Thomas Jefferson, and Buckminster Fuller used this *exact* technique. Other great minds likewise used naps to their advantage including Nikola Tesla, Thomas Edison, Napoleon, and Winston Churchhill.

Naps are the key to direct Theta brainwave access. Theta brainwaves are the brainwaves of hyper awareness. The more theta you have during your waking hours, the more creatively intelligent you are–it’s really that simple.

As far as longevity, Fuller lived to 87. DaVinci into his late 60’s. –Both lived over DOUBLE the average life expectancy of the men of their time.

Monophasic sleep is the “norm” for North American culture. We sleep at night, and work during the day. Polyphasic sleep consists of multiple sleep/ wake incidents scattered throughout the day. A sleep schedule with an afternoon nap is an example of polyphasic sleep. There is evidence to suggest that humans were originally suited to a polyphasic sleeping routine, rather than the arbitrary monophasic one that we are used to. For starters, almost all animals in nature conform to polyphasic behavior. In addition, polyphasic behavior is the predominant mode of sleeping for human infants, and even in the later years, children have to slowly be weaned from the afternoon nap. Furthermore, when people are isolated from the external environment – so that they cannot determine the actual time of the day from natural cues such as sunlight, or artificial cues such as clocks or television programs – they tend to exhibit more napping behavior instead of retaining the single monophasic sleep period during the “night.” Finally, it appears that naps – relatively brief sessions of sleep – are more effective in refreshing the mind, than longer periods of sleep. In a sense, we were taught to “unlearn” this natural way of sleeping, when we had to adjust to the arbitrary 9-to-5 schedule.

Oh, and on 3 hours of sleep a night, I have one cup of coffee at the most per day.

The sleep cycle is a beautiful thing.

Interesting Note: Your brain cells reset their sodium & potassium ratios when the brain is in Theta state. The sodium & potassium levels are involved in osmosis which is the chemical process that transports chemicals into and out of your brain cells. After an extended period in the Beta state the ratio between potassium and sodium is out of balance. This the main cause of what is known as “mental fatigue”. A brief period in Theta (about 5 – 15min) can restore the ratio to normal resulting in mental refreshment.

Update: I originally wrote this article in early 2003, it’s now mid 2009, and my sleep patterns are regular, unwaveringly bi-phasic.  I’m healthy, I don’t eat any sugar whatsoever, my cholesterol is low and my productivity is higher than it has ever been.  Some people have wondered how they would transition into a sleeping pattern like this.  The keys (from my experience only) are:

  1. Measure the length of your sleep cycle. 90 minutes is a good average, but for some people it is different. Mine has actually changed in the last few years from 90 to about 75.  Now, if I hit the pillow at 7:00, I wake up for the first time at 8:15. Never, ever using an alarm clock. Because of the change in sleep cycle length, I now get 4 cycles per day. Usually three late at night, and one in the evening.
  2. The key thing is, it MUST be divided up into two distinct sleep sessions per day.  It’s not enough to just get 4.5 hours and say “that’s my sleep done for today”.  You’ll have a hell of a time staying awake for the remaining 19+ hours. You’ve got to divide it into two (or more) sleep sessions. The REM sleep you achieve has to be spaced throughout the day for it to have the proper “flushing” effect. In many non-western cultures, the mid-afternoon nap, siesta, whatever you want to call it, is a completely standard practice.

For anyone interested, here’s a picture I found that shows what sleep cycles “look like”:

First, we have a single cycle:

A typical sleep cycle.
A typical sleep cycle.

And here is how they divide up into the night.

Sleep cycles through the night.
Sleep cycles through the night.

Remember, waking yourself up in the middle of a sleep cycle, say in stages 3 or 4, are the days when you feel groggy and can’t figure out why, yet, other days, get less sleep and wake up feeling alive and alert.

Disclaimer: I’m not a doctor, I’m not a therapist, or anything of the sort. I’m just a human being who discovered this by accident, experienced it, then looked it up to see if there was any research into stuff like this.  It started because I was getting less sleep at night, and was tired, so I started having naps after work (at first, accidentally on the couch), but found unexpectedly that it suddenly rejuvinated me the next day, and made everything else easily doable. The rest was history.
photo credit: martinak15 via photopin cc

20 thoughts on “The Power of the Sleep Cycle

  1. Great information. I’ve been living my life this way for years and never have encountered such a clear statement of what happens . Wish I’d seen this earlier on. Found it by accident when I woke up at about 12:30 a.m after going to sleep at 9:15 pm. fully alert and ready to go. decided i could not possibly be the only one who does this and there you were albeit 5 years ago.anyone else? (i’m new here)

  2. Since you rely on your creativity as part of your career, you might now want to, but have you experimented with GABA supplements to improve your sleep quality. The best I’ve tried is Jones GABA. It seems I can have lucid dreams now and again on this product, and my creativity feels boosted the following day.

    Also, since you are both creative and technological, you might appreciate this, there are apps for the iPhone that detect sleep movement, and try to wake you at the correct point in your sleep cycle.

    Without something like that I don’t think I could only sleep 3 hours, as I don’t naturally wake up between sleep cycles until after about 9 hours.

    Current research seems to indicate that we process/refresh older memories in our later sleep cycles, if that is true, I’m curious how your long term memory functions on your sleep program. What are your thoughts on this?

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