Polyphasic sleep can reduce daily sleep time from eight hours to two, a huge incentive for anyone who sees sleep as a waste of time. They might consider sleeping hours that become waking hours as “free time.” Believing it to be the forgotten sleep of our ancestors, there are those who are fighting to bring polyphasic sleep back. Are they acquiring time for free, or does their sleep-style carry a cost?

What is polyphasic sleep?

Unlike a monophasic sleep cycle, which includes one core sleep block, or a biphasic cycle which includes a core sleep block with a midday nap, a polyphasic sleep cycle requires more than two sleep blocks each day. Sometimes this involves a core sleep block with multiple naps throughout the day, and sometimes all sleep blocks are of equal length. The most extreme cycle includes six 20 minute periods of sleep spaced evenly throughout the day, commonly referred to as the “Uberman sleep schedule.” However, any schedule which uses more than two sleep blocks is considered polyphasic sleep. *

Why polyphasic sleep?

While a sleep system is not required to reduce total sleep time to be considered polyphasic, it is often the goal of polyphasic sleepers. Advocates describe it as a “highly efficient” sleep system which “usually results in feeling healthy, feeling refreshed upon waking and extremely vivid dreams.” It is also believed to increase the tendency to have lucid dreams. Ideally it allows for a mere two hours of sleep while the remaining 22 hours of the day are at peak performance. If the system works, you get six extra hours of wakefulness compared to those getting the recommended eight hours of sleep in a monophasic cycle. To put that into perspective, you could watch the entire Toy Story trilogy every day and still have an extra hour to do something productive.

Who sleeps polyphasically?

It is not only individuals seeking to minimize their sleeping hours that decide to subsist solely on naps. Polyphasic sleep is the preferred cycle of a great majority of species (approx. 86%). The blind Indus dolphin, for example, sleeps for only 90 seconds at a time, but gets 7 hours of sleep every day. That’s almost 300 sleep episodes every day! Adult humans are one of a handful of exceptions to this polyphasic tendency. Even infant and elderly humans have a polyphasic sleep cycle, as the naps which are phased out with the shift to adulthood make their comeback later in life. It is possible that adult humans do not sleep polyphasically because their environment or lifestyle is not conducive to naps. A Swiss study found that with unemployment came a more than 100% increase in naps. Without the incentive of a job, the subjects of the study naturally experienced increased polyphasic behavior.

How does polyphasic sleep work?

The argument for why polyphasic sleep works even with a significant reduction in time spent asleep is that our bodies only need REM sleep. NREM sleep is considered a waste of time, which would be unfortunate for monophasic sleepers because, in a normal sleep cycle, we go through about an hour and a half of NREM sleep before we enter REM sleep. In polyphasic sleep, however, our bodies become REM sleep deprived and almost immediately enter REM sleep upon falling asleep. One blogger explains that his “record so far for lying down, falling asleep, having a dream, and waking up and remembering the dream is 13 minutes.” If this is true, and polyphasic sleepers almost immediately enter REM sleep, they will get their recommended amount of REM sleep each night.

Why does polyphasic sleep fail?

While there are sources which advertize the benefits of polyphasic sleep, most experts are in agreement that polyphasic sleep is actually unnecessarily risky, if not downright dangerous. This risk does not come from missed REM sleep, as polyphasic sleepers meet their REM quotas each day, but from missed NREM sleep. During NREM sleep, the body repairs and regenerates tissues, builds bones and muscle, and strengthens the immune system.

Additionally, one of the core principles of the system is building up a large sleep debt and using that to rapidly enter REM sleep after laying down to take a nap. While it seems obvious that the sleep debt is incurred because the person is only getting two hours of sleep a night, this is backed up by the one minute it takes to fall asleep, suggesting that if a polyphasic sleeper were to take an MSLT, he or she would be in the Twilight Zone. While the quota for REM sleep is met, the sleep debt is never paid back, thus the consequences of sleep deprivation are still likely to manifest themselves.

It should be noted that the maximum carryover sleep debt is believed to be approximately 50 hours. This means that if it is impossible to attain enough sleep to meet your needs, and therefore a sleep debt would be built up regardless, the sleep debt effects of polyphasic sleep would be less pronounced. However, detrimental effects of lost NREM sleep would still be present.

Polyphasic sleep can also fail from a lack of motivation to maintain the sleep schedule. It can be difficult to run on a different schedule than the rest of society, thus social pressures, added onto potential tiredness experienced, can cause a polyphasic sleeper to abandon their efforts. Or, maybe, they’ve seen the Toy Story trilogy one too many times.

Conclusion

While it is common in the rest of the animal kingdom, a polyphasic sleep schedule does not offer free sleep to humans; there is clearly some associated cost.

*There actually is not a consensus on the definition of polyphasic sleep, the broadest definition is any sleep system which is not monophasic, so if there is more than one sleep block, it is considered polyphasic. A stricter definition is that there cannot be any one sleep block which accounts for more than half of all sleep.

References:

“Alternative Sleep Cycles: You Don’t Really Need 6-8 Hours!” High Existence Site Wide Activity RSS. N.p., n.d. Web. 01 Mar. 2013.

Dement, William C., and Rafael Pelayo. Dement’s Sleep and Dreams. N.p.: n.p., n.d. Print.

“How Much More Will You Achieve When You Reduce Your Sleep Debt?” Learn About Sleep Debt To Optimize Your Efficiency & Improve Your Life. N.p., n.d. Web. 01 Mar. 2013.

Pavlina, Steve. “Polyphasic Sleep â Response to Reader Feedback.” Polyphasic Sleep â Response to Reader Feedback. N.p., n.d. Web. 01 Mar. 2013.

Stampi, Claudio. Why We Nap : Evolution, Chronobiology, and Functions of Polyphasic and Ultrashort Sleep. Boston: Birkhäuser, 1992.

“Uberman’s Sleep Schedule || Kuro5hin.org.” Uberman’s Sleep Schedule || Kuro5hin.org. N.p., n.d. Web. 01 Mar. 2013.