What if you didn’t need to sleep? Scientists know surprisingly little about why we need to spend one-third of our lives on our back unconscious. However, we know that it must be more than mere tissue repair and rest, as an adult giraffe requires just 1.9 hours of sleep despite weighing over a ton.
I’ve often resented the need to sleep so much. It feels like wasted time in a 21st-century world that requires us to squeeze everything out of every moment. So what if I told you that we don’t actually need to sleep as much as we do, that there were ways around this wasted time? What if I told you that this might not even be a natural way that humans are evolved to sleep? That we can choose to ignore the modern sleep cycle in pursuit of something more natural and potentially healthier for our body and mind?
What Is REM Sleep?
Your sleep can be divided into two distinct categories, REM (Rapid Eye Movement) sleep and NREM (Non-Rapid Eye Movement) sleep. Whilst you sleep, you cycle through stages of both, with REM sleep accounting for roughly 25 percent of your average night’s sleep. A “normal” night’s sleep consists of about seven-and-a-half to nine hours divided into five or six sleep cycles.
We get most of our REM sleep in the last third of the night. I spoke briefly with Dr. Irshaad Ebrahim from the London Sleep Centre to get a better idea of what is happening during REM sleep:
This is for all intents and purposes the defragging of our disk drive…So what you have is the organization of the filing, the disk clean up, and the defrag happening in REM sleep, you also have the hardware getting tested, such as the cardiovascular system.
REM sleep is when your eyes are moving rapidly back and forth under your closed eyelids, hence the name. This is when you’re dreaming; your muscles are paralyzed to ensure you don’t act out your dreams. REM sleep is also known as “paradoxical sleep” or “desynchronized sleep,” due to its similarities to your brain activity whilst awake. Your brain waves are largely low voltage, rapid, and desynchronized.
Phil Lawlor, a Sleep Expert at Dormeo, explains:
REM sleep is responsible for our emotional and visual processing. Scientists have discovered a correlation between this sleep stage and activity in the visual and emotional areas of the brain. It’s this stage of sleep when dreaming occurs, and it’s thought that dreams are our brain’s way of processing and making sense of complicated thoughts and feelings.
The rapid eye movement associated with REM sleep is caused by Ponto-Geniculo-occipital (PGO) waves, bursts of electricity originating in the brain stem. Your brain is much more active during REM sleep than any other part of our sleep cycle. Your brain also uses more glucose and oxygen whilst in REM sleep than it does when you’re awake. Something is requiring more energy than a conscious mind whilst we sleep.
Interestingly, according to Phil Lawlor:
Those who spend a longer time in REM sleep have generally been able to recognize facial expressions more accurately and are better equipped to deal with emotional stimuli. Some studies have also found that those who get plenty of REM sleep display less fear-related behaviours.
Healthline states that REM sleep detoxifies the brain; consolidates memory; processes emotions and learning; balances out your blood sugar and metabolism; and energizes your immune system. It also improves mood regulation and mental concentration. Without enough REM sleep, you can suffer from a lower immune system and struggle with cell growth and repair.
We might get all those benefits from REM sleep, but as we mentioned that is only a quarter or less of the entire time spent asleep. The rest of our sleep is NREM sleep. NREM sleep can be further subdivided into a number of categories:
- Falling asleep
- Light sleep
- Deep sleep
Healthy adults require between 13 and 23 percent of their nightly sleep to be REM sleep; that’s roughly 60-110 minutes. Dr. Ebrahim explains, “We get the bulk of our deep or regenerative sleep in the first third to half of the night. And this is NREM sleep, it’s also the state where growth hormone is secreted.”
As you age, you require less and less deep sleep. Deep sleep is when your breathing slows, your blood pressure drops, and your energy is renewed. Dr Raheel Karim, a Consultant Psychiatrist from Pall Mall Medical Karim says “The later stage of non-REM sleep is a deeper, more restorative sleep, as the body works to strengthen the immune system and repair damaged tissue. It is most difficult to wake someone during this sleep stage.”
REM sleep appears to be for our mind, but NREM is for our body. We need both if we’re to wake up feeling fresh and rested in the morning!
Sleeping More Than Once Per Day
In the modern world, we sleep in one big chunk, from say, 11 PM until 8 AM. Whilst this seems natural, this may not even be a natural sleep pattern for humans. Some theories suggest we may be more naturally evolved to split our sleep into two parts.
Whilst studying Nigerian tribes, anthropologist Paul Bohannan noted that they referred to “first sleep” and “second sleep,” as two distinct phases. Historian Roger Ekirch also comments in his book Sleep We Have Lost: Pre-Industrial Slumber in the British Isles that literary sources throughout the ancient world refer to a first and second sleep, everything from Homer and Virgil to Canterbury Tales. Seemingly this is not an odd phenomenon, but one that has been seen widely across human history.
Dr. Ebrahim explained that the shift of humans from biphasic to monophasic sleep was a result of the introduction of shift work and the industrialization of the modern world.
Pre industrialization we slept in these two periods at night, then along came the shift work. Our natural circadian rhythm is to sleep at night, but this differs according to where you are in relation to climate. Mediterranean and tropical cultures tend to stay awake later in the evening when it is cooler and then take a siesta in the afternoon. So for these cultures, biphasic sleep has been around forever.
Thomas Wehr attempted to recreate these patterns by limiting participants in a study to only 10 hours of light per day, after which they were asked to go to bed in a dark room. Within days, the participants found their sleep split into two parts, with one to three hours in between in the middle of the night!
Biphasic And Polyphasic Sleep
So what if you wanted to split your sleep, but not spend these hours awake during the night? Well, the Spanish are already familiar with this style of sleep pattern, known as the Siesta. It involves a six-hour sleep plus a short afternoon nap. Short naps in the day are associated with better cognitive function, but the trick is to adapt your body. If you’ve never slept in the afternoon, you may find it difficult to fall asleep.
“As we age, we spend less time in the deeper stages of sleep,” according to Dr. Karim. He told me, “A biphasic sleep schedule is becoming increasingly popular for older and retired people, or those with suitable working patterns. This means sleeping for five to six hours per night, waking early, and taking a nap around midday.”
But, what if, for some crazy reason, you wanted to go even further? Matt Mullenweg, the creator of WordPress, mastered the “Uberman” sleep pattern. It involved sleeping in six periods a day (of about 40 minutes each), with about 2.5 hours in between each nap. He told Tim Ferris, “This was probably one of the most productive periods of my life.”
Dr. Ebrahim and I discussed why people struggle with sleep, and why people are attempting these outlandish variations to our normal sleep patterns. He believes that we have been “burning the candle at both ends for some time. Your brain needs X amount of sleep per 24 hours…People are now trying to manage their sleep. Your brain needs a certain amount of sleep and I think we should give it that.”
How Much Sleep Is Really Enough?
It’s not easy to do. On an episode of his podcast, The Time Ferriss Show, Mullenweg told Ferriss that if he missed just one of his six naps a day, he would be “wrecked.” However, despite the difficulties, he might have continued the Uberman if it were more socially acceptable, but he abandoned the extreme sleep schedule after getting a girlfriend.
So how much sleep really is enough? That depends on how many times a day you’re sleeping!