Ooookay, since I told you guys that I would explain what this is, and since I missed school and have nothing else to do, I shall explain. It's super interesting.
Okay, let's begin with the basics of sleep first. There are 2 types of sleep. NREM, which means No Rapid Eye Movement, which is composed of 4 parts, and REM, which is Rapid Eye Movement.
If you already know all this stuff, you can skip these next 5 or so paragraphs.
NREM stage 1
stage one is the first stage of sleep (duh). You're basically just drifting in and out of sleep while your muscles relax. It's not a very important phase, since this is just the phase where you fall asleep.
NREM stage 2
This stage makes up 40% to 50% of your sleeping time. Brain waves slow down with an occasional burst of fast waves. Eye movement stops at this stage.
NREM stage 3
Your brain uses really slow brain waves, called delta waves, along with some other bursts of brain waves. It's the first stage of deep sleep. During stage 3 it can be really hard to wake someone up.
NREM stage 4
This is the second stage of deep sleep. In stage 4, your brain is almost exclusively using delta waves.
REM stands for rapid eye movement. This stage is the most important, since this time is when your brain works to heal your body and rest. This is also the stage where dreaming occurs. In this stage, your heart rate gets faster, your eyes move rapidly, your breathing becomes fast and shallow, your blood rate increases, and your muscles are paralyzed. The average person that sleeps 8-9 hours will usually get around 1-2 hours of REM a night. The more REM sleep you get, the more rested you feel.
Polyphasic sleep involves taking multiple short sleep periods throughout the day instead of getting all your sleep in one long chunk. A popular form of polyphasic sleep, the Uberman sleep schedule, suggests that you sleep 20-30 minutes six times per day, with equally spaced naps every 4 hours around the clock. This means you’re only sleeping 2-3 hours per day. I’d previously heard of polyphasic sleep, but until now I hadn’t come across practical schedules that people seem to be reporting interesting results with.
Under this sleep schedule, your sleep times might be at 2am, 6am, 10am, 2pm, 6pm, and 10pm. And each time you’d sleep for only 20-30 minutes. This is nice because the times are the same whether AM or PM, and they’re consistent from day to day as well, so you can still maintain a regular daily schedule, albeit a very different one.
How can this sleep schedule work? Supposedly it takes about a week to adjust to it. A normal sleep cycle is 90 minutes, and REM sleep occurs late in this cycle. REM is the most important phase of sleep, the one in which you experience dreams, and when deprived of REM for too long, you suffer serious negative consequences. Polyphasic sleep conditions your body to learn to enter REM sleep immediately when you begin sleeping instead of much later in the sleep cycle. So during the first week you experience sleep deprivation as your body learns to adapt to shorter sleep cycles, but after the adaptation you’ll feel fine, maybe even better than before.
It requires some discipline to successfully transition to this cycle, as well as a flexible schedule that allows it. While you’ll be sleeping a lot less, apparently it’s very important to sleep at the required times and not miss naps.
A side effect of this sleep schedule is that you need to eat more, since you’re spending more time moving around.
The downside to this sleep schedule is that it can be inflexible. I’ve read that you can delay naps by an hour if necessary, but missing a nap can cause a rapid crash that takes a while to recover from. This means you only have about 3.5 hours of waking time between naps, 4.5 hours if you push it. So this can restrict your options a bit. Of course, you have to balance that sacrifice against the gain of many extra hours per day, every day.
This schedule is often considered to be less “extreme” than other forms of polyphasic sleep, as it contains a “core sleep” of a few hours, usually in the early morning, as well as short naps during the day. In reality this system may be more physically difficult to adjust to, as the core sleep will delay the sleep deprivation which triggers the brain to adapt to instantaneous REM sleep upon falling asleep. However, the system may be easier to adjust to psychologically than other sleep schedules, as the core sleep provides a sense of delineation between one day and the next.
Everyman sleep is more freeform in structure than other polyphasic sleep schedules; sleepers nap whenever they feel tired rather than at set points throughout the day.
Polyphasic sleeper PureDoxyk notes that not every combination of core sleep and naps works – too short, a core sleep is only as effective as a regular 20-minute nap, while too long a core sleep makes the sleeping schedule more similar to siesta sleeping than true polyphasic sleep.
And that is the information I gathered. I copied the entire subject of polyphasic sleep and everyman sleep from http://www.stevepavlina.com/blog/2005/10/polyphasic-sleep/ and http://www.suite101.com/content/different-polyphasic-sleep-schedules-a117476
Check the sites out if you want more info. I found all this super interesting and I'd like to try it out some day.