from wikipedia.org Every 4 hours sleep 20 minutes. A couple friends experimented with this to increase productivity and saw great results until one got sick and needed to stay in bed and ruined his routine. Each sleep cycle (during monophasic, or traditional 8 hour sleep) is ~90 minutes and only in the later part of each cycle do you experience REM. When your body gets acustomed to polyphasic sleeping, supposedly REM sleep occurs almost immediately as you fall asleep (based on your body's survival mechanism-- it knows it will only get 20 minutes and needs every bit of it) Instead of waking up, warming up your body, having peak energy then crash, followed by peak energy and crash again, you are instead just constantly resting only as much as you need to for the next 4 hours. From testimonials I've read, the first week is terrible. But, after that, many claim a much higher alertness and energy level while awake. The only time the body will crash is when you are due up for another nap anyway. Anybody ever flirt with this idea or look into it? ps: Seeing as sleep is literally nutrition for the body and mind, F&N seemed like a sufficient place to put this.