Times have moved on a bit since the days when sleep, like lunch, was for wimps and no self-respecting high-flier would admit to getting up later than 5.30 in the morning. Now with corporate wellness programmes and sleep tracking apps all telling us to get more kip, and high-tech start-ups selling scientifically designed ‘sleep surfaces’ (that’s beds to you and me) the importance of shut eye is back at the top of the agenda once again.
Even entrepreneurs, famous for their gung-ho attitude towards minimal sleep, are getting the message that it matters. But considering that we all spend around a third of our lives doing it, the truth about sleep is that it’s a very individual business and a lot of the things we think we know about it don’t bear very close analysis. Here are five things that may surprise you about shut-eye.
There's no such thing as the ‘right’ amount of sleep…
Eight hours a night is widely cited as the gold standard of a good night’s kip, but the norms vary widely and we all need a different amount of sleep to be at our best. Iron Lady Margaret Thatcher famously got by on three or four and still managed to run the country, whereas the 30th President of the United States, Calvin Coolidge, preferred a more languid 10 (admittedly in the days pre-social meeja and FOMO). Koala bears can spend 20 hours a day in the land of nod, whereas some elephants, it has emerged, may only nap for a couple of hours at a time. Six hours a night is enough for many people, but listen to your body – if it’s telling you to sleep more then you probably should.
But there is such a thing as not enough…
Sleep deprivation does impair cognitive function – studies on soldiers who had slept for three hours or less have shown that lack of sleep leads to poor decision making and a loss of ‘situtational awareness’ i.e. the ability to grasp the bigger picture. It can take you twenty minutes longer to respond effectively to a crisis if you have not had enough shut-eye. And despite the stereotype of hard partying twentysomethings, as you get older you actually need less.
The coffee kick is an illusion
As anyone who has blearily inhaled one extra-strong flat white after another following a hard night knows, caffeine does make you feel more alert. But sadly it’s only a feeling – it doesn’t actually improve your mental performance at all. If you have been up all night you are just as likely to make bad decisions and be short-tempered and irrational after coffee (or even perish the thought, Red Bull) as before it.
No-one really knows what it’s for
Despite the fact that all higher mammals – and even many primitive creatures right down to millimetre long nematode worms – sleep, there is still a big debate about why. Something important is surely going on, but what exactly? The theories range from our bodies going into ‘repair’ mode, fixing cellular damage caused while we are awake, to the need to replenish stocks of ‘ready use’ energy-giving metabolic chemicals depleted during the day. It is also thought to play a role in creating our memories, with sleep (and dreaming in particular) acting as a kind of ‘filing system’ whereby the events of the day are filtered, sorted and transferred from short-term to long term storage in the brain.
The jury’s out on whether we really are sleeping less than in the past
Yes there are numerous surveys suggesting that people feel they would like more zeds, especially in the UK. But they would probably say the same about money, or sex – wanting more doesn’t mean you don’t have enough. 100 years ago, 60 or 70 hour working weeks were commonplace and it’s only since the end of WWII that the nominal 40-something hour week has become established. Sleeping conditions – thanks to central heating and more comfortable beds – are clearly better. But thanks to our phones, the internet and the TV we are faced with more distractions come bedtime, so getting yourself ready to go to sleep may be more challenging than it was in the days when the only alternative was a cup of Ovaltine and a book.