Polyphasic sleep refers to the practice of sleeping (or napping) multiple times during a 24hr period instead of getting all your sleep at once (a.k.a Monophasic sleep). We recently picked up on a fascinating post mentioning Zeo from the "Polyphasic Sleep" Google Group and asked the author, Oki, for this guest post as a way to launch the first group-and-data-driven Polyphasic Sleep Experiment. Enjoy!
My Monophasic Sleep Pattern
Here's a story about my use of the Zeo to develop a new "polyphasic" schedule for myself over the past 6 months or so...
I went back to pure monophasic for a couple weeks and studied my Zeo data on it. Within the first few days I seemed to have re-adapted to mono sleep and didn't note significant changes in my cycles over the remainder of the 2 weeks.
I did notice, as has been described extensively in the literature, that I emphasize Deep sleep at the beginning of the night and REM at the end / early morning. I didn't realize how extreme the difference is though! In my case, (I haven't studied the literature enough to know how general or reliable the phenomenon is) I got almost all (~90%) of my Deep sleep at the beginning of the night (first 2 cycles) and the same for REM at the end. Light sleep was enriched in the middle cycles.

Developing A New (Polyphasic) Schedule
This made me think about sleep efficiency and maximizing Deep and REM and minimizing Light.
Doing some simple math I saw that if I cut out the middle hours of the night I would still get as much, if not more, Deep and REM as is recommended by many sleep "experts." The idea was to take advantage of my natural circadian rhythm. My goal is to sleep at least 65 mins of Deep per day (not counting the power nap which I rarely record on my Zeo) and 90 mins of REM.

I picked these numbers somewhat arbitrarily but they are close to the average amount per night for someone of my age.
For my evening nap I decided to sleep 2 hours starting between 8 and 10pm. If I stay up much later than 10 I get *very* sleepy and have a hard time waking up. I also noticed that when I slept monophasically, I usually finished my second Deep cycle after about 2 hrs. Thus for my first nap I would sleep: Light, Deep, REM, Light, Deep, Wake.

To calculate the morning nap, I subtract the amount of REM I got from my evening nap (typically 5-25 minutes) from my total REM goal (90 minutes) and multiplied the difference by 3. I then sleep for that amount in order to get enough REM every day.
90-20 = 70; 70 x 3 = 210min (so I need to sleep 3.5 hrs in the morning)
Admittedly, 90 minutes is a pretty conservative estimate for an entire day, as I almost always get more than enough REM during the morning nap (45%-50% is often REM). Sometimes I do sleep less than 3.5 hours if I'm crunched for time in the morning, though I always end up with 90-120 minutes of REM no matter what.

In addition, I like to take a single power nap (25 mins) sometime during the day. If I nap at 4pm or later, I sometimes have a hard time falling asleep for my evening nap so I try to aim between 12 noon and 4pm.

Sometimes I've replaced the power nap with some caffeine (tea or 1/2 cup coffee), but I prefer not to. I can also push through the day without the power nap and I'm just a bit sleepy in the afternoon.
For the nap itself, I usually sleep in my car (and rarely use the Zeo) so I can't say too much about the data there; if I had to guess based on previously recorded power naps, I would estimate 15 mins Light, 5 mins Deep, and 3 mins REM for each. I would like to do something more rigorous for recording my power naps and am very interested in hearing about others and your power nap results.
Notes & Thoughts
- Took very little adaption. The only tricky part was training myself to go to bed between 8 and 10pm instead of midnight but that only took a few days to get used to. Bare in mind that I've been experimenting with polyphasic for the past 2 years so napping comes pretty easy to me.
- Easy to pop in and out of. I have the old problem of a partner who I sleep with fairly regularly. If I join her for the morning nap there isn't much of a problem because I just try to time my wake up to be similar to hers. If we go to bed for the evening nap, however, it's a bit awkward and annoying for me to be woken and get active in the middle of the night while she is trying to sleep. For one, I'm a much heavier sleeper than she is. We've tried a bunch of things over the past couple years and it just doesn't work. Cuddling is important to a relationship :) That's ok! If I sleep monophasically once or twice a week it doesn't mess up my schedule at all! I still usually hit the mid-day power nap if this happens. Also, if work or a social engagement absolutely can't be avoided or worked around at that time I can still do it and just sleep monophasically when I finally get to bed. I really need to get an extra power nap in there before I do whatever is going to keep me out late, however, or I'll start getting really sleepy by 10pm.
- Don't have a hard time doing any normal activity at night including computer work or reading.
- No apparent decrease in athletic ability. I'm still able to do vigorous exercise for hours at a time.
In summary I've gone from ~50% Light sleep on mono to ~35% Light on poly. The amount of extra time I get isn't dramatic (sleeping 5-6 hrs /24 hr period), but I feel much better on polyphasic than I do on monophasic, and it is a fairly flexible schedule that works for me.