Can You Really Gain Waking Hours By Practicing Polyphasic Sleep?
The average person spends one hour asleep for every two hours they spend awake. In other words, we sleep for about 1/3 of our lives. Some consider that ratio too large, and claim they can actually improve their efficiency and general functioning by sleeping for only three hours a day in short, scheduled bursts. Is this really possible?
Sleeping for a few hours at brief, regular intervals is known as polyphasic sleep, as opposed to monophasic or biphasic sleep, in which one sleeps for one or two solid blocks, respectively. Enthusiasts cite the success of famous polyphasic sleepers like Leonardo da Vinci, Nikola Tesla, and Thomas Edison. (Notably, none of the above sleep schedules are well-documented).
Humans sleep in cycles of stages: one rapid eye movement (REM) stage and three non-rapid eye movement (NREM) stages. We typically cycle through the stages four or five times per night, spending roughly 60% in the first two stages of relatively light NREM sleep, 20% in deeper or "slow-wave" NREM sleep, and 20-25% in REM sleep.
The idea behind polyphasic sleep is that slow-wave and REM sleep is essential for proper functioning. The theory goes that by habituating our bodies to sleep in short intervals, we can force ourselves to rapidly enter slow-wave and REM sleep, effectively skipping the other non-essential stages and allowing us to sleep for only a few hours a day.
For those of us who live and breathe the idea that there are not enough hours in a day, polyphasic sleep seems like a welcome alternative. Who wouldn’t want four or five extra hours to play with? After all, many animals have polyphasic sleep schedules (a fact often cited by advocates). About two percent of people known as natural "short sleepers" seem to function normally on just a few hours of sleep per night – though there’s no evidence to suggest that anyone can train their bodies to work this way.
The main problem with this theory is that we simply don’t know enough about the significance of each sleep stage. To argue that we can safely skip a few stages is premature in an age where sleep science is only decades old. The purpose and function of regular sleep are far from exhaustively researched, let alone polyphasic sleep. At this point, there are no studies indicating that one train oneself to function on minimal sleep, on any schedule. Evidence to the credit of polyphasic sleep is largely anecdotal, and even then, mostly short-term.
In other words, the jury is out, but we urge erring on the side of caution. Chronic sleep deprivation is too serious to experiment with, with consequences ranging from fuzzy thinking to an increased risk of chronic disease. We recommend getting seven to nine hours of undisturbed sleep per night and doing so on a properly fitted mattress.
Just one last point – if you ever decide to experiment with polyphasic sleep, make sure you refrain from operating heavy machinery!