Well behind us are the times when the planet was black at night, only every so often the darkness disturbed by light of an occasional fire, at first from a lightning, later from bonfires of the first human geeks.
Some time ago we have created an animation based on our user data from SleepCloud showing how people are staying awake though out the night all over the world.
The shining dots are clusters of awake people. Note for example Japan, US East coast or the UK. You can see that the world truly never sleeps
Artificial light, the industrial revolution, caffeine usage, the shiny screens of our electronic gadgets and all the activities we can still do after sunset have changed how we sleep. In this study we had a look at the numbers in our more than 20 million sleep record database to see how bad/good our sleep really is.
When we started with sleep tracking at home in 2010 our primary target was improving sleep and the wake up experience to boost productivity and cognitive abilities during the day. This is an interesting goal to achieve, but over the time we found out the terrifying truth. Wast majority of people in the world sleep really badly.
It is not a matter of boosting someones productivity or fine-tuning sleep phases. Not at all! In fact most of the people out there are constantly sleep deprived. Their sleep duration is insufficient and they sleep irregularly. Lack of productivity during the day is their least problem.
Being basically unconscious for several hours during the night is a massive evolutionary disadvantage. And if the benefits of sleep would not outweigh the risks of sudden death from predators, inability to look for food or mate there would hardly be any reason for us to fall asleep. Instead sleep is a common phenomenon in the animal kingdom. And an essential process which keeps us healthy.
Sleep is vital for nearly every process in our body. With insufficient sleep our immune system suffers. This can lead to increased risk of cancer, increase rick of coronary deceases, overweight or disrupted blood sugar levels. We have already named the biggest killers who decrease our life expectancy the most and we aren’t far from truth for most people if we summarize this into: the longer you sleep the longer you live!
Never the less sleep is also absolutely essential for our mental health. And luck of sleep contribute to anxiety or depression so common in today’s population.
Still many people think about their sleep as waste of time, but they can’t be more wrong. You can have a perfect diet, be physically active but still with insufficient sleep your health will suffer.
So let’s have a look at the data. We have done this research in the past. But now we made sure to eliminate any statistical pitfalls to get the best estimate, including only users with consistent records, aggregating first per-user, removing countries with insufficient data, testing median against mean etc…
I you look at the map above and the table below, some of the findings are alarming. The overall median for all Sleep as Android users is below 7 hours (6:56) of sleep. Even the best country in the list – Finland – is under the 7:30 hours recommended in our app as the baseline. Not speaking the worst performers like Japan (6:08), Korea (6:03), India (6:22), Brazil (6:34), Spain (6:48) or Turkey (6:28)…
|Country||Country code||Sleep duration median|
|United Arab Emirates||ARE||6:30|
|United States of America||USA||6:58|
Evidence from many studies show the average duration for most countries in our table are insufficient for a healthy sleep.
There is sufficient support for the data, in fact you would have a hard time finding a bigger sleep database in the world.
But we are awake of two issues with the data with a reverse effect. First, sleep app user data may be slightly biased toward people with sleep issues such as insomnia which may underestimate the duration. Second, actigraphy – the method used to measure sleep in the app Sleep as Android – has a tendency of overestimating sleep duration – as laying awake in the bed not moving is difficult to distinguish from sleep in some cases.
What is even more alarming than the overall sleep duration is the trend. Look at the chart below. The only country which actually shows any yearly growth in the sleep trend is Japan and probably just because it is bouncing off from the very bottom.
In all the other countries / regions the trend is downward with the US showing up to 14 minutes decrease in average sleep between 2014 and 2019. The data have statistical significance over 3 sigmas with around 5 thousands participants in the US and Central Europe in each year and around one thousand for the other regions.
More over, sleep duration is really just one piece of the puzzle. In another study we did on sleep regularity we have shown that most of our users sleep irregularly. Just 10% of our users sleep regularly, 30% are significantly socially jet-lagged and the rest are completely irregular.
Regular sleep is a key premise to get maximum out of your sleep time. Your body expects the sleep to occur in certain times, prepares for it and if we shift it, the time we spend in bed is not used efficiently. This would make the figures in the table above look even worst when they were adjusted for sleep irregularity.
To see more on how we evaluated sleep regularity and what figures we did measure please see here.
To conclude, the world sleeps badly and we need to take actions. In modern society we see a massive outbreak of various lifestyle diseases, typically auto-immune diseases. In some countries we see a decline in life expectancy for the very first time in modern human history. We should seriously consider if our lack of sleep is not to blame at least for some of those observations.
Everyone of us need to start with himself. Look at your sleep and find out how you could improve it at least a little bit in terms of duration and regularity. I’m sure very soon you will get rewarded by feeling better about your life, being more productive and being healthier. The additional time in bed will greatly pay of!
Last but not least, hopefully with better sleep, we will all make it into the technological singularity one day! 😉