Sleep Cycles

Sleep Cycles

Throughout a human lifespan several different sleep cycles are utilized. As a baby we naturally take advantage of frequent intervals of sleep and alert periods. Slowly we transition into a biphasic sleep cycle before finally settling into the traditional monophasic cycle. However, over time we slowly return back to a polyphasic sleep cycle as we get older. So what is the most effective way rejuvenate our bodies?

Biphasic sleep cycles or siestas are popular in some countries such as Spain and is the most popular polyphasic sleep cycle. The siesta involves a large sleep period of 5-6 hours and a nap lasting less than two hours occurring at some point in the day. Evidence has been accumulating in regards to the benefits of such a sleep cycle. Benefits include enhancements in information processing and learning, overnight improvement in motor skills and improvements in alertness. Research has also been done to discover just how long the nap period should last and when. Monitoring the brain during naps lasting longer than an hour show evidence of four times more REM sleep than that in shorter naps. However, a shorter nap in the middle of the day has shown to produce more immediate benefits. So if having one nap during the day, do more naps expand on these benefits?

Several extreme polyphasic sleep cycles exist that consist of several period of short naps rather than one longer period of sleep. Two of the most popular cycles of this type are the Dymaxion cycle and Uberman cycle. The Dymaxion sleep cycle consists of four evenly distributed naps of 30 minutes. Very few people have been able to master the Dymaxion sleep cycle, as it does not provide enough time in REM sleep to avoid sleep depression. The Uberman cycle consists of six evenly distributed naps of twenty minutes throughout the day. A variation exists where eight distributed naps of twenty minutes are utilized instead of six. Both cycles produce about two hours of sleep throughout the day. However, only 5% of the population can survive on less than six hours of sleep. Those in this small fraction of the population contain a genetic mutation that allows them to remain healthy with less hours of sleep.

Overall sleep is a necessity for health and wellbeing. Too little and we become ineffective. With the increasing complexities of daily schedules, less and less people get the necessary sleep they need to be successful throughout the day. To make up for the lacking hours we look to caffeine to provide the perk we need to make it through the day. Better benefits may be seen with the introduction of a polyphasic sleep cycle. From positive research in the benefits of naps it can be reasoned that a short “siesta” during the middle of the day can do more than a cup of coffee to rejuvenate the body and provide more minutes of precious REM sleep. While one nap during the day has tremendous benefits, substituting nocturnal sleep with several naps throughout the day does not have as effective results. Most of the population requires at least six hours of sleep and extreme polyphasic sleep cycles do not provide the amount of REM sleep that is necessary for health and wellbeing. So, if you would like to be more productive throughout your day make time for a quick nap.

Sources:

• The National Institute of Mental Health Power Nap Study. 2002-07-01.
• Tietzel, Amber. The Short-Term Benefits of Brief and Long Naps Following Nocturnal Sleep Restriction 2001.
• Harmon, Katherine. Rare Genetic Mutation Lets Some People Function with Less Sleep 2009. Scientific American.