I’ve had a love/hate relationship with sleep over the years. It’s always been a rollercoaster, short fits of nighttime sleep, followed by a long 9-10 hour crash, then normal 8 hour sleep for awhile, then the shortening of sleep in a quest for more time during the day, crash, repeat.
However, now with secure office space, I have finally been able to implement a new sleep schedule. It isn’t as hardcore as the Uberman sleep schedule, but it does allow me to pick up a few hours a day. It’s a bi-phasic schedule, also known as an afternoon nap.
Radical, I know. But here comes the science!
Humans have a sleep cycle of about 90 minutes. That means left undisturbed, the body will naturally go through some number of cycles while it sleeps, and then wake up on it’s own. The first 60 minutes or so are increasingly deeper levels of sleep. The next 20 minutes is REM sleep, followed by a few minutes of very light sleep, then the cycle repeats. Being awoken in the middle to end of a cycle will make you groggy and disorientated because this is when your deepest sleep stage and your REM sleep stage (both of which are needed to repair and recharge your body) occur. Which means when doctors say you should get 8 hours of sleep, they’re actually screwing you up by waking you in the beginning of a new cycle instead at the end of a complete cycle.
Try it sometime, take a nap in the afternoon and make sure you are not disturbed and try to block out the sunlight. You’ll awaken on your own some multiple of 90 minutes after you’ve fallen asleep.
The other fun aspect of these cycles is that your first cycle has the longest period of deep sleep. Deep sleep is responsible for hormone regulation and tissue repair, not to mention that the strongest effects of sleep deprivation are from inadequate deep sleep. Your deep sleep stage actually gets shorter as you repeat cycles. So your fourth sleep cycle of the night is doing less for you than your second sleep cycle of the night which is doing less for you than your first sleep cycle.
Conversely, REM sleep length actually increases each cycle, with the first cycle having the shortest REM stage of the night. REM sleep is when we dream. It’s needed for processing emotions, memories, and stress. It is also believed to be vital to learning and developing new skills. However, if REM sleep is disrupted one night, your body will go through more REM the next night to catch up. Not to mention that you can actually dream during other stages of sleep. If you are sleep deprived, the body makes up your deep sleep deficit first, then your REM sleep deficit.
So I’ve broken my sleeping into two sleep periods. I take a 90 minute nap around 1:30 PM in my office, then a 4.5 hour nap (3 sleep cycles) at 1:30 AM. This way, I get two first cycle deep sleep doses (which easily equal the deep sleep contributed by later cycles in the same sleep period). While initially I might short myself on REM sleep, my body should adapt by moving through the early sleep stages quicker to get to deep sleep and then REM sleep to make up the deficit.
Despite my many years of being a morning person, I’ve actually been able to make this switch quite easily and I now get all my quiet work time at night. Then I’m able to get up rested with the rest of the family to start the day.