‘You will be stunned': A sleep expert's pre-bedtime tips

The Age

15-05-2025

He calls himself a 'humble servant of this thing called slumber', but that would be selling British neuroscience professor Matthew Walker short. The author of Why We Sleep: Unlocking the Power of Sleep and Dreams, Walker is the expert of choice on one of life's great mysteries (and necessities).
Why do we sleep? Twenty years ago, the crass answer was, 'We sleep to cure sleepiness', which is the fatuous equivalent of saying, 'I eat to cure hunger.' Now we ask, 'Is there any major physiological system of your body or any operation of your mind that isn't wonderfully enhanced by sleep when we get it, or demonstrably impaired when we don't get enough?' And the answer seems to be no.
I love a good nap. So did Thomas Edison, right? Edison understood the creative brilliance of sleep and used it ruthlessly as a tool. He was also a habitual napper who would wake up and then write down all of the ideas he was getting. He called it 'the genius gap': [the short phase] between lucid, waking consciousness and the depths of non-conscious, deep sleep. It's probably one of the reasons why no one's ever said you really should stay awake on a problem.
Barack Obama says he can survive on five hours of sleep. Nikola Tesla was said to exist on three. Is there any optimal amount? It's seven to nine hours. Chronically sleeping less than seven hours is associated with cardiovascular disease, diabetes, immune and inflammation issues, cancer, hormonal issues and, of course, Alzheimer's disease and dementia. There is a very small subset of the population that we now call 'natural short sleepers', but statistically you're more likely to be struck by lightning.
You note that adolescents naturally fall asleep later, meaning school starts far too early? Teenagers have been lumbered with this incessant chronic sleep debt, and if you look at models throughout the world where school start times are delayed, attendance rates increase and truancy rates decrease, while academic grades increase and psychiatric referrals decrease. I don't mean to trivialise things – getting children to school is not easy, and parents have to get to work – but if you look at the data, when sleep is abundant, minds flourish, and when it is not, they don't.
What purpose do dreams serve? Dreaming is almost like a form of informational alchemy. During dreaming, we start to collide all the recent things that we've learnt with the back catalogue of information that we've already got, and as a consequence we wake up with a revised mind: a wide web of associations that is capable of divining solutions to previously impenetrable problems. It's also a form of overnight therapy. With the special chemical cocktail that happens during dream sleep, it's almost like a nocturnal soothing balm, taking the sharp edges off those painful, difficult experiences. Dreaming strips the bitter emotional rind from the informational orange.
What's the most common cause of insomnia? Sometimes I consider insomnia as the revenge of things we haven't worked through during the day: the stuff causing anxiety and stress. You have to get your mind off itself. How? First, meditation. Next, with what's called a body scan, relaxing as you focus on each part of your body from head to toe. If you don't like the sound of that, try box breathing: inhale for five seconds, hold it for five seconds, and then exhale for eight seconds. Another thing that you can do is take yourself on a mental walk down the street in 4K hyper-vivid detail. Do not count sheep.
Loading
What are your top tips for good sleep? Try to stay away from too much caffeine in the afternoon and limit your alcohol use, because it will fragment your sleep. Your bedroom temperature should be cool: about 17 to 18 degrees. As for unconventional tips, set an alarm for one hour before you expect to go to bed, then shut down all the lights in your house. You will be stunned by how sleepy and soporific that will make you feel. In that same hour before bed, try to limit the use of devices – not because of the blue light but because they hit the mute button on your sleepiness and cause what's called 'sleep procrastination'. Also, go to bed at the same time and wake up at the same time. I know it sounds desperately pedestrian, remarkably vanilla and deeply boring, but if you want to sleep, regularity is your first best step.
Do we undervalue sleep? We are still in the mentality of competitive under-sleeping, and whoever the PR agent for sleep has been, we probably should have fired them long ago because there's a terrible stigma about getting sufficient sleep, which is strange. No one looks at an infant sleeping during the day and says, 'What a lazy baby', but we do that to adults. Don't think of sleep as a cost to today; sleep is an investment in tomorrow.