Sleep is important, but feels old-fashioned. Our lifestyle these days rarely takes sleep into account – we rather try to work as much as we can, then engage in some fitness training, and finally land ourselves in a club or pub. We pump ourselves with coffee in the morning and during the day, so life seems to roll on as if there is not much need for sleep. At some point we eventually feel exhausted, so we book expensive vacation trips and again spend our nights on the dance floor or elsewhere.
We seemingly invest in our health – by staying physically active, eating ecologically grown food, and taking vacations. However, besides all this, we forget what is most important – sleep. Sleep is equally vital to an artist, athlete, car salesperson, scientist, and every one of us. Good sleep helps us make the most of our lives. Let’s see why sleeping is so important and how to maximise its benefits.
To be honest, scientists are still not quite sure why sleep is so crucial throughout the animal kingdom. There are various theories about sleep function, but let’s just highlight two of them here.
One reason is that our brain cells need rest. They need rest because, contrary to our body cells, brain cells aren’t normally renewed. Although new brain cells are indeed born in a few regions of our brain and thousands of brain cells die daily, the large share of our hundred billion brain cells accompany us throughout our lives. Thus, sleeping gives individual brain cells some rest. One should not get the wrong impression here – during sleep the brain and the neurons are not switched off, they are still very much active, but in some sleep phases this activity permits “time-outs” for the single neurons.
Secondly, the size of the synapses – the minuscule connection spots between the nerve cells – also needs to be renormalized. Our brain is plastic and in constant change – most importantly, the strength and thus the size of the billions and billions of synapses changes on a daily basis.
If it holds true that on average our synapses tend to grow bigger with learning, then the brain faces a problem: bigger synapses require more space within the brain which is just not available; bigger synapses need more energy, which is hard to transport; and bigger synapses limit brain plasticity. Bigger synapses are not sustainable. It has been suggested that during sleep all synapses get sized down. One could say that sleep is the price one has to pay for neural plasticity. Indeed, it has been convincingly shown that sleep is beneficial for learning and memory.
How to sleep?
1. Always get to bed at the same time – your body and brain will get used to falling asleep at that time and will get ready for it.
2. Cover your windows so the room is dark – evolutionally, our sleep is related to dark nights; these days we get disturbed by street lights and passing cars.
3. Sleep in cool temperatures (e.g. 19–20° C).
4. About half an hour prior to going to bed, stop watching TV or staring at your smartphone or laptop – switch off your screens, as they keep your brain awake!
5. Try to get about 8 hours of sleep every night – it is important to know that some of us are fine with six, while others need ten hours of sleep, so be honest with yourself and find your perfect sleep dosage.
6. If you wake up during the night, don’t feel bad about it – our ancestors also slept in two shifts during the night. Read a book!
7. Exchange your coffee during the day for a 15–20-minute nap – even a short sleep enhances the acquisition of new memories and finding new solutions.
8. Don’t take sleeping pills and advise your friends and relatives to avoid them as well – research shows that sleep-inducing drugs don’t actually enhance sleep and have annoying side effects.
9. Use ear plugs and separate beds from your partner, if needed. Sleep is as sacred as marriage is.
10. Don’t skip sleep, as sleep deprivation is connected to higher risk of overweight, cardiovascular diseases, and some serious mental dysfunctions.
Jaan Aru is a researcher at the Computational Neuroscience Research Group and at the Talis Bachmann Lab at the University of Tartu. The shorter Estonian version of this post was originally written for the MIHUS magazine and appeared on Jaan Aru’s personal blog.