Polyphasic sleep means sleeping multiple smaller amounts of times in a 24h cycle rather than in a single shot at night. The advantage of this practise is that it reduces your amount of sleep, with as little as 2 hours per day with the extreme schemes: the Dymaxion and Uberman methods.
|Name||Total sleeping time||Method|
|Monophasic||≈8.0 h||8 hours major sleep episode.|
|Biphasic||≈6.3 h||6 hours major sleep episode and one 20 minute power nap.|
|Everyman (with 2 naps)||5.2 h||4.5 hours major sleep episode and two 20-minute power naps.|
|Everyman (with 3 naps)||4 h||3 hours major sleep episode and three 20-minute power naps.|
|Everyman (with 4 - 5 naps)||≈3 h||1.5 hours major sleep episode and four to five twenty-minute power naps.|
|Dymaxion||2 h||Four 30-minute naps (every 6 hours).|
|Uberman (from German 'Übermensch')||2 h||Six 20-minute naps (every 4 hours).|
There is apparently no agreement whether this has adverse effects, but most accredited sources discourage it, despite observing little, if any, negative consequences..
One source condemns it for resulting in decreased mental and physical ability, increased stress and anxiety and a weakened immune system. Most practitioners—which I do not count as "accredited"—are on the other hand positive and assure the scheme can be sustained over years, the main difficulty being the impracticability of the schedules.
Buckminster Fuller is the first famous "polyphaser" who experimented and advocated the method. Claudio Stampi is a scientist who studied polyphasic sleep thoroughly. He published Why We Nap: Evolution, Chronobiology, and Functions of Polyphasic and Ultrashort Sleep as a result of his studies. Other famous figures include Leonardo da Vinci, Napoleon or Tesla.