In our increasingly hectic and digitally connected world, many people regularly sleep for less than 6 hours per night.
Personally, I prefer to sleep for at least 7 hours, but for various reasons sometimes have to make do with a measly 5 or 6.
Despite it being increasingly common to skip sleep, only a relatively small number of people appear truly able to still be at their best, day after day.
I’m definitely not one of those, as much as I wish I were!
The night owl and early bird
Natural short sleepers are often simultaneously a night owl and an early bird. They may go to bed long after midnight, but still manage to rise and shine in the early hours of the morning.
They can then motor on through the day at full speed without feeling any need to have a nap or load up on caffeine.
This ability to survive well without much sleep sometimes starts as a child and can run in families. And rather than showing any ill-effects, short sleepers are often more outgoing, enthusiastic and ambitious than normal.
However, if you feel tired when awake, fall asleep during the daytime or need to catch up on sleep at the weekends, you might not be a true short sleeper.
According to Dr. Daniel J. Buysse, from the University of Pittsburgh Medical Center, only 5 in every 100 people who believe they need less than 6 hours’ sleep are natural short sleepers.
The other 95, as you’ll see later, are probably winging it and could be suffering more consequences than they realize.
The 3 types of short sleepers
There are many reasons why some people get less than the recommended 7 to 8 hours of sleep every night. It could be due to circumstances beyond your control, such as work demands, parenthood or health issues.
It might also be lifestyle choices like spending time with family or friends, or being online late at night instead of sleeping.
However, large sleep surveys and medical studies I’ve seen tend to consider three general types of short sleepers:
1. People who sleep less because of a sleep disorder
Some people regularly sleep less than they’d like to because of a sleep disorder, such as insomnia. They are less likely to be at their best the next day, and perhaps suffer the effects of sleep deprivation.
2. People who think they are short sleepers
Some people will regularly sleep for less than 6 hours due to work, study or social reasons. They might think they are fine, but in the long-term are likely to suffer for it.
They might develop coping mechanisms to stay awake, such as drinking coffee or staying active. But really, they would benefit from more sleep.
3. The true short sleepers
The lucky few who don’t need to sleep more than 6 hours, feel no real ill effects and thrive on their rare ability. The genuine short sleeper.
Many people are capable of managing reasonably well on less sleep for a couple of nights. But the true short sleeper can do so night after night.
Personally, I can handle a night or two of just 4 or 5 hours fairly well. But if the pattern continues for too many nights, my concentration and alertness go downhill rapidly. So I’m definitely not a natural short sleeper.
Why can some people survive so well on less sleep?
A challenge that researchers face is that natural short sleepers don’t think they have a sleep disorder. So they are less likely to seek medical help or take part in research projects.
Although there still isn’t a definitive answer, there are two main theories:
- Natural short sleepers have a specific gene
- They are more efficient sleepers
Is it in the genes?
In 2009, researchers at the University of California reported that they’d found a gene variation – hDEC2 – in a mother and daughter, who were both natural short sleepers. They both routinely went to bed after midnight and woke up naturally at 4 in the morning.
In 2014, a large team of researchers also found evidence that this gene mutation is involved in short sleepers.
This time, they looked at 100 twin pairs. The twin with the gene variation typically slept for significantly less time than the twin without the variation, and also seemed more resistant to the ill-effects of sleep deprivation.
Are they simply more efficient sleepers?
In the September 2016 issue of Brain and Behavior journal, a team from the University of Utah reported that short sleepers may be more efficient sleepers.
They used MRI scans to study the connections between different parts of the brain. Connections that are fundamental to how we see the world – how we think and process all the information that bombards us every day.
The brain scans allowed them to compare the brain activity of 3 groups of people:
- Those who slept normally
- Those who reported their lack of sleep had an impact on daytime alertness and well-being
- Those who stated that it didn’t have an impact
Short sleepers who reported no real effects from a lack of sleep had enhanced connectivity between 2 areas of the brain:
- The hippocampus – a region of the brain associated with memory
- The sensory cortices – which process sensory input from your eyes, ears etc
One of the study authors, Dr. Jeffery Anderson said:
That’s tantalizing because it suggests that maybe one of the things the short sleepers are doing in the scanner is performing memory consolidation more efficiently than non-short sleepers.
The team suggested that the brains of short sleepers might be more efficient at undertaking the various tasks we associate with sleep.
Are short sleepers really still alert?
The Utah University team also made some interesting observations about whether short sleepers are actually always as alert as they might believe.
The scans were conducted while people were asked to stay awake. The researchers found that some of the brain activity for the short sleepers was similar to that normally seen during sleep.
So it’s possible that people were drifting off to sleep in the quiet and relaxing atmosphere of the scan.
They also monitored the number of head movements and found that the short sleepers appeared to have more than the non-short sleepers. This suggested to the team that the short sleepers needed more external stimuli to stay awake.
The team considered that some of the short sleepers, who reported no impact on daytime effectiveness, might still be suffering from the effects of sleep deprivation. Perhaps they compensate by seeking increased external stimuli.
These findings could have important safety implications. For example, short sleepers might be more susceptible to falling asleep in the absence of other stimuli, such as when driving long distances at night.
Personal characteristics of short sleepers
Dr. Christopher R. Jones, an associate professor of neurology at the University of Utah, has also studied short sleepers. He notes that they don’t seem to show some typical effects of sleep deprivation, such as irritability and apathy. He says:
These people are typically characterized by their optimism, outgoing nature, and rapid speech.
Dr. Jones also observes that natural short sleepers don’t tend to be overweight, which can be an issue for some people with chronic sleep problems. So not only can natural short sleepers get by with much less sleep, but they even thrive on it.
Can you train yourself to be a short sleeper?
Unfortunately, the simple answer appears to be no. Many people do find ways to compensate for their lack of sleep – coffee, sugar, keeping their brain active or even through exercise. But it’s not the same.
The sleep professionals appear unanimous that you can’t actually train your body to sleep less. At least not without some adverse effects on your performance or health.
The military has also been interested in seeing if they can train their people to survive on less sleep, such as during high intensity operations.
They have found that with practice soldiers can get by for periods with less sleep. But if this goes on for too long, their effectiveness quickly reduces.
There are also some very limited trials which suggest you might be able to bank sleep by sleeping more before a period of reduced sleep. Again though, you can plan your sleep cleverly, but you can’t turn yourself into a true short sleeper.
Famous short sleepers – or maybe not?
Throughout history, there have been several famous people who reportedly didn’t sleep much.
Artists, such as Leonardo da Vinci. Scientists, including Benjamin Franklin, Thomas Jefferson, Thomas Edison and Albert Einstein. Politicians, like Winston Churchill.
But I wonder how many of these really were natural short sleepers?
For example, Winston Churchill is reported to have not needed much sleep at night. Apparently, he was also fond of having an afternoon nap, so perhaps he wasn’t a natural short sleeper after all, but more of a polyphasic sleeper.
Thomas Edison, who invented the light bulb, also thought sleep was a total waste of time and something we could do without entirely. In 1914 Edison said:
There is really no reason why men should go to bed at all.
Equally, historical reports suggest he had a cot in his laboratories and would take the occasional nap.
How can I tell if I’m a genuine short sleeper?
I haven’t seen any formal self-testing processes for natural short sleepers. However, a couple of experts have suggested one way of testing yourself is:
- Take a long vacation of at least two weeks, and preferably somewhere you’re not going to suffer from jet lag.
- You might sleep for longer on the first couple of nights to catch up on lost sleep.
- After that, go to bed at your normal time, or preferably when you’re tired, and don’t set your alarm clock.
- See how long you sleep over a period of a few days, which should suggest how much routine sleep you need.
Hopefully, this test won’t stop you enjoying your vacation. You might also have little choice but to go back to your same short sleep routine at the end. But at least you’ll have a better feel for how much sleep you personally need to function at your best.
There are very few people who can truly function well on less sleep every night. It seems that most short sleepers probably struggle with a degree of sleep deprivation and would benefit from a couple of extra hours every night.
It might be that natural short sleepers have specific genes which give them this capability. Equally, perhaps their brains are more efficient at undertaking the housekeeping roles associated with sleep, such as memory consolidation.
Do you sleep for less than 6 hours per night on average? Do you find you cope well during the day, or do you struggle with the effects of sleep deprivation?