What is good sleep and how do I get it? - Insights from Matthew Walker
Studies show that no part of your body or mind is unaffected by sleep, from your blood sugar levels and cardiovascular health to memory and mental health.
However, many of us feel that we don’t get enough hours or high-quality sleep.
So, what can we do about this?
If anyone is dedicated to helping us sleep better, it’s sleep expert Dr. Matthew Walker. Walker is a Professor of Neuroscience at UC Berkeley and the founder of the Centre for Human Sleep Science. You may have heard of his global bestseller, Why We Sleep, or his viral TED Talk, Sleep is Your Superpower, which garnered over 17 million views.
During the Sydney Writers’ Festival on 27 May 2025, I was lucky enough to hear Walker talk about his work.
After acknowledging research that suggests sleep affects every single psychotropic condition, Walker describes sleep as emotional first aid - an overnight therapy that can ease symptoms. Meanwhile, poor sleep can be a predictor of worse overall health and even lower longevity.
But it’s not just about the amount of sleep - quality is equally important, and we need to spend time in ‘deep sleep’ to be refreshed.
‘The best bridge between despair and hope is a good night’s sleep.’ - E. Joseph Cossman.
What is good sleep, and how do I get it?
We’ve all been asked, ‘How did you sleep?’ so subjectively we have a gauge on our perception of good sleep.
But what about the objective answer to this question? That’s where Walker’s research - and that of many other scientists - comes in.
One way of looking at it is through the QQRT framework - Quantity, Quality, Regularity, Time - or, as Walker describes, the ‘four macros of good sleep.’ Let’s break these down starting from the top. These factors work together to create a healthy sleep pattern and improve overall well-being.
Quantity: While individual needs vary, adults generally require between 7 and 9 hours of sleep. When rounded to a whole number, the percentage of adults who are not impacted by just six hours of sleep per night or less… is zero!
Quality: Focus on the structure and continuity of your sleep, as it is just as important, if not more important than, quantity. This includes getting restful, deep sleep throughout the night. If you sleep for a significant portion (say 85%) of your time in bed, that’s great. However, those who wake up regularly throughout the night are considered to be getting low-quality sleep.
Regularity: Emphasise consistent sleep schedules, going to bed and waking up at the same time each day, even on weekends. Regularity helps anchor your circadian rhythm. In a study of 60,000 individuals, regular sleep predicted an overall 47% reduction in all-cause mortality. (Jessica R. Lunsford-Avery et al.)
Timing: Align your sleep schedule with your natural chronotype (e.g., morning person, night owl). Understanding your chronotype and adjusting your sleep schedule accordingly can improve sleep quality. For the most part, this is genetically determined, so it’s ‘fiendishly difficult to change.’
Walker emphasises we shouldn’t stigmatise night owls as being lazy, as it’s genetic! Timing is essential, as sleeping out of sync with your chronotype can significantly hinder sleep. In other words, a night owl forcing themself into bed at 10 p.m. will likely sleep worse than if they stayed true to their chronotype and hit the pillow at 1 a.m. Sadly, as night owls often don’t get the sleep they need due to traditional 9-5 office hours, they are therefore more at risk of disease.
By optimising these four factors together, you can improve your sleep, boost your daytime energy, and enhance your overall health and well-being.
‘Sleep is Mother Nature’s best effort yet at immortality. From all that we’ve seen in biology, it’s the Swiss Army knife of health.’ - Matthew Walker.
Why isn’t sleep prioritised in our culture?
Unfortunately, not only is sleep under-prioritised, but in some sectors of society, a lack of sleep is actively celebrated from the corners of social media filled with ‘hustle culture’ influencers advocating to stay on the grind and sleep five hours a night, to corporate bosses and to passionate, young interns competitively undersleeping.
As Walker puts it, some people wear their lack of sleep as a badge of honour.
But, looking at what the science shows us, shouldn’t we be more inclined to celebrate getting eight and a half hours of sleep a night? Even over the fact that sleep makes us more efficient, you could argue that - given that quality sleep requires structure - getting ‘good sleep’ is a sign of efficiency and organisation.
Walker humorously points out that no one looks at a baby taking a nap and says, ‘What a lazy baby!’ We understand this is biologically necessary. Somewhere along the line, we start to forget that rest is equally required for adults (we are the same species, after all), and in some cases, we actively chastise people for it.
He hopes the tide is changing for Gen Z, who seem more inclined to invest in themselves and their mental health.
Walker asks us to question what we value and why we equate business with importance. After all, given that studies have shown those with 6 hours or less of sleep are 30% more likely to be involved in a car accident, those who declare war on sleep are increasing the risk of accidents. Isn’t that worth prioritising?
‘I believe it is time, as a society, that we reclaim our right to a full night of sleep. Without embarrassment, or stigma of laziness, as in doing so we can be reignited with the most powerful elixir of life.’ - Matthew Walker.
Sleep and Disease
For those over 40, Walker notes that it’s the increased risk of Alzheimer’s and Cancer that leads people to become interested in his work.
In fact, it was dementia that led Walker down the path of sleep science. While studying different types of dementia during his PhD, he saw a correlation between dementia patients and the impact on the sleep centre of the brain, and became incredibly passionate about the subject.
‘We come into this world with no knowledge at all, but if we’re lucky, we leave with a complete wealth of information, memories and experience. But with dementia, we leave the world much more similarly to when we entered it, and I think that’s a tragedy. Why would you put yourself at higher risk?’
Walker’s approach to sleep
Adequate quantity - He ensures he has an adequate opportunity in terms of time in bed, judged on his biology, and sticks to his consistent sleep schedule, even at weekends.
Winding down and a ‘go to bed’ alarm - Unwinding from the day is essential. For Walker, that means setting a bedtime alarm about an hour before bed. His wind-down routine then includes a digital detox (putting the phone away), dimming the lights, and a 10-minute meditation.
Don’t use bedtime for reflection - when your head hits the pillow, you may tend to reflect or ruminate. But, as Walker puts it, everything in the dark seems twice as bad as in the light of day. Some may find it helpful to journal in the early evening or engage in a guided meditation or activity at bedtime that helps take their mind off things.
Make sure your bedroom is set for sleep - some may find blackout curtains and noise machines helpful. (A silk sleep mask and sleep playlist are cheaper alternatives.) Meanwhile, keep distractions such as phones out of the bedroom, or at the very least, turn off data access if you use a playlist for sleep. Ideally, sleeping in a cool room around 18°C (64°F) can enhance sleep quality.
Wake up well - Matthew tries to get immediate sunlight in the morning, at least 20-30 minutes of natural daylight exposure in the first two or three hours of the day to help his circadian rhythm. And by keeping your phone in the bedroom, you won’t be tempted to swipe immediately upon waking up, as the tsunami of notifications isn’t healthy for our waking brains.
What about caffeine? Don’t worry, Walker doesn’t tell us to give up coffee! However, he advises trying to limit ourselves to no more than three cups a day, and ideally, no more after lunchtime. (Unless you’re flying, in which case, cut out the coffee and alcohol on the flight, and set your phone to the arrival time zone as soon as you get on board to help you adjust.)
And napping? Matthew advises against napping, but a 20-minute power nap before 2 p.m.
In summary, Walker makes it really clear that sleep is not an optional lifestyle - it’s a necessity. Research has made it increasingly transparent about the impact of sleep on various aspects, including memory retention and learning, reproductive health, cardiovascular risk, immune function, and gene expression. So, it’s really worth prioritising.
However, Walker also points out that sleep shouldn’t feel like a chore, so he didn’t want us to treat his talk like homework.
‘Don’t be afraid to live a little,’ says Walker. But, when you’re able to, try to improve the quantity, quality, and regularity of your sleep, and you may find you’ll be able to live a little more, too.