Since finishing high school (back then a time of rather high workload) I have been intrigued with sleeping multiples periods a day, so-called polyphasic sleep, which promises a serious increase in the amount of time being awake, i.e. that can be used productively.
The idea is based on the observation, that toddlers and some animals sleep multiple times a day, and even people locked inside a bunker beneath ground zero tend to adopt a biphasic sleep cycle: waking up around midnight, staying awake for a few hours and then continuing to sleep.
Now, the argument goes like this: If you are taking into account, that a lot of sleep is spent on light sleep and that REM-sleep has the greatest effect on physical recovery, it should be possible to cut sleep down to the essential amount needed by spreading sleep periods across the day, covering only REM-sleep.
Various systems have been proposed for polyphasic sleep, the most extreme versions being the Uberman system (20 minute naps every 4 hours = 6 x 20 minutes = 2 hours of sleep per day) and the Dymaxion system (30 minute naps every 6 hours = 4 x 30 minutes = 2 hours) and more moderate systems such as the Everyman one, including 3 hours of core sleep after midnight and three 20 minute naps spread across the day.
Despite the promise of “more time” these system might seem at a first glance strange and impractical, as most of us are used to monophasic sleep during night time. Which also corresponds to the recommendation of the National Sleep Foundation. And as Matthew Walker points out in his book “ Why we sleep “, sleep is one of our most important basic needs and sleep deprivation makes us less conscious, hampers our ability to learn new things or even makes us more susceptible to heart diseases.
That’s also why he advocates to keep regular sleep hours of 7–9 hours a day, alongside some general recommendations such as controlling room temperature ( 2–3 degrees lower as compared to during day), avoiding blue light before sleeping and staying away from alcohol and marihuana (a nice summary of his ideas can be found in this blog article by Bill Gates or by this Youtube video).
But despite all the recommendations for 7–9 hours of core sleep a day, insomnia is one of the most widespread problems of modern society, which means sleeping regular hours every night just isn’t reality for most of us either. Especially during these troubled times of Corona crisis, people might find it difficult to detach themselves from day-to-day matters and sustain regular sleep hours.
So most likely you currently got different issues than theorizing about sleep systems. But when you think of it, now might actually be a good time to do such sleep experiments in practice! Despite not all, but at least some of us (including PhD students in theoretical physics!) have gained far more flexibility during these times, working from home and thus being able to schedule working hours and leisure time to ones liking.
There is also no need to go straight after the Uberman system and be disappointed if it doesn’t work out of the box. Only very few people sustain such a sleep pattern over an extended time period, which include most notably PureDoxyK, who coined the term Uberman in 2000 and has written a book about it, and the American self-help author and motivational speaker Steve Pavlina. These systems are, as intended, pretty rigid and you need to allow for some adjustment time, just as you would, when traveling between different times zones — it’s basically like traveling between social time zones.
But experimenting with biphasic sleep or a moderate Everyman sleep system, might help to fall asleep more easily, feel more refreshed during day and thus sleep more “efficiently”. This said, polyphasic sleep is mostly promoted by bloggers, rather than bullet-proof, randomized clinical studies. So most importantly you need to figure out what works for you: What is your demand for sleep? How to make multiple sleep periods compatible with daily life? And what would you do with the time you could gain from sleeping better and less?
There is no single scheme that fits all. But doing some self-experiments probably won’t hurt.