Earlier this week, I gave a talk at Google on the science of sleep.
After 5 years of reading into the scientific literature, I was forced to squeeze everything I know into a 20-minute presentation.
So below is everything I’ve learnt about getting baby-coma sleep – from 100+ academic papers, every sleep book out there, hours of podcasts, interviewing neuroscience professors, and completing a 10-week CBT-i course for insomnia sufferers.
(Not enough time to add references for all points – I will do this soon…)
Let’s get straight into it!
Go to sleep and wake up at the same time every day.
Simple, but works like magic. It’s the first thing we were advised to do on my insomnia course, and the first thing Harvard Medical School advises to improve sleep.
The exact times are up to you; just stick to them religiously (or as best you can).
If you want to optimise further and you have more control over your schedule, you can choose a sleep/wake time based on your chronotype.
Some of us have “late” chronotypes – we like to sleep later. And others an “early” chronotype.
Find yours with this quiz by Dr Michael Breus.
Just 5 seconds of blue light from your mobile phone at night is enough to screw up your circadian rhythm (your body’s internal clock – how it works out when to sleep).
Blue light says “hello, it’s the morning”, time to be productive! Not what you want before relaxing sleep time.
Blue-light-blocking glasses can help here. Go buy a pair.
Download f.lux on your desktop to make your screen go orange, reducing the blue light seeping through.
Turn on night mode on your phone after 6pm. Or if you’re really serious, turn on red mode (iPhone only).
Blackout blinds can block out external light pollution.
If you’ve got other annoying light sources – like those red standby lights on your TV or a light-up laptop charger – gaffa tape over these.
Dim all your lights as much as possible – the darker the better.
And 1–2 hours before bed, turn those screens off completely.
If you still need light to find the toilet or catch some late-night reading, use a dim amber light lamp. Red and amber light mimics a sunset, triggering a release of melatonin (your friendly neighbourhood sleep hormone) in your brain, sending you to zzz land.
Temperature is almost as important as light.
Back in hunter-gatherer times, we’d sleep outside at night, at cooler temperatures.
So a decrease in temperature signals to the brain: it’s time to sleep!
You can decrease environmental temperature with a thermostat – start turning it down after 8pm.
Counterintuitive, but you can take a warm bath before 8pm; after which your body will cool down, telling your brain to sleep as night ensues.
(Do not take a warm bath after 8pm, though, as your body will already have started naturally cooling down by then…heating it back up will tell your brain the Sun’s back out – i.e. it’s morning!)
These are mattress toppers; they go on top of your bed and pump cool water around, keeping you cool while you sleep.
Even cooler, you can set heat alarms where the water will warm up when you want to wake up…just like the sun would naturally warm up our hunter-gatherer ancestors.
Speaking of the Sun…sunlight is an extremely powerful tool for regulating circadian rhythm and optimising health holistically.
Sunlight alarms are a good start, but only go up to 10,000 Lux.
The actual Sun goes up to 110,000 Lux.
(Yes, that’s over an order of magnitude difference…)
No substitute for real sunlight, so go outside in the mornings for a 15 minute walk. This is enough sunlight to stimulate the photosensitive retinal ganglion cells in your eyes, telling your brain to wake the f*ck up.
(Added bonus: sunlight is associated with a cascade of positive biological effects from increased happiness to strong bones and immunity. Sunlight switches on over 50 genes epigenetically, all associated with positive health outcomes – isn’t that amazing!?)
The best my sleep has ever been was in Mexico when I went swimming every morning under the Sun.
Your bedroom should be for sleep and sex only.
If you eat or work in bed, your brain will neurologically associate bedroom with wake-time activities.
You don’t want this. You want your brain to think “bedroom = sleep (or sex)”.
So throw out all non-sleep, non-sex items from your bedroom; and only use it for sleep and sex!
Your brain will associate the rest, and before you know it you’ll crash every time you enter your bedroom at night.
Your bedroom should also feel safe.
In hunter-gatherer times, sleep was an easy time to get eaten, so your brain won’t sleep unless it feels safe it can.
Weighted blankets can help here — the added weight feels like getting a hug at night.
And aromatherapy diffusers, loaded with bergamot and lavender, also help induce sleep. And over time, your brain will associate those smells with sleep, creating a powerful habit loop.
Magnesium glycinate and zinc can both be taken regularly to help with sleep.
Vitamin D3 in the mornings helps regulate your circadian rhythm.
(How much to take of the above is individualistic so check examine.com to personalise your dosage)
And 1000mg of curcumin (an anti-inflammatory) can help offset the inflammatory effects of bad sleep.
If your sleep is really f*cked, 5mg of melatonin once in a while can help get you back on track. I take it when I’m jet-lagged or totally screwed up after an all-nighter.
Lavender and chamomile teas are also useful!
But more important than the supplements you take is the time you eat your last meal.
If you haven’t fully digested dinner by sleep time, your body will stay up at night, digesting away, messing up your sleep.
I hit my highest ever sleep scores during a 7-day fast (my body just had nothing to digest!); and Bryan Johnson (dude who sold his company for $900m and now runs a neuroscience company) only eats breakfast so all food is fully digested before sleep time.
Avoid eating anything heavy 5+ hours before sleep.
I used to use an Oura ring to track my sleep.
Then switched to a Whoop — uglier but more useful data!
Both track your sleep times, sleep quality, and heart rate variability.
Progressive Muscle Relaxation
Developed by Harvard University to help navy seals get to sleep during gunfire, Progressive Muscle Relaxation will knock you out.
Watch this to learn the technique; after that you can do it yourself!
If you suffer from anxious racing thoughts at night, write them down and you’ll feel less crazy.
Your journal can be messy or just a few bullet points. Sometimes writing down actions you’ll take tomorrow to resolve the worries spinning around is all you need.
Gratitude journalling is also gold for sleep. Hard to feel anxious and grateful at the same time. Noting down three things you’re grateful before bed is an easy happiness-booster and sleep-inducer.
This is a weird one.
Again, in hunter-gatherer times, sleep was an easy time to get eaten, so your brain won’t sleep unless it feels safe it can.
But if your eyes are closed when you’re in bed, your brain has no way of knowing if its environment is secure.
And so, counter-intuitively, insomnia researchers have found keeping your eyes open as you try to sleep improves sleep scores.
The theoretical mechanism is straightforward: keep your eyes open → brain gets to see there’s no surrounding danger → less stress, lowers cortisol → induces sleep.
Try it out: next time you’re really struggling to sleep, instead of forcing your eyes shut, keep them open for as long as you can (blinking is allowed) and watch yourself drift away.
Working till 11pm and then sleeping at midnight doesn’t work.
Your brain just doesn’t have enough time to “switch off”, to wind down from “work mode” and relax.
Hard stops are the answer here.
My hard stop is 7pm. It doesn’t matter how many deadlines I have, how many unfinished tasks I’m panicked about, I cannot keep working past 7pm.
I even have a piece of code on my Mac that shuts it down automatically at 7pm.
Give yourself a hard stop and just stick to it. It doesn’t matter if now and then you don’t finish your todos, in the long run, the better sleep will pay off.
You also need a hard stop on your mobile phone usage.
For me it’s 11pm, an hour before I head to bed.
I have a bed time alarm set on my iPhone for 11pm, 11:01pm, 11:02pm, etc., all the way till 11:59pm.
So when that first alarm goes off, I can either deactivate 60 alarms…or just turn my phone off, switch to my Kindle and wind down for bed.
Naps, Yoga Nidra & Orgasms
20-minute naps after lunch are great for squeezing in extra sleep if you’re low on z’s from the night before.
60–90 minute naps work well, too, if you’re really low on sleep (i.e. less than 5 hours).
And I use Pzizz (J.K. Rowling’s favourite app) to help me nap.
Don’t nap too late or too early as it’ll interfere with your nighttime sleep cycle. After lunch is ideal, but take an evening nap and you won’t be tired enough to sleep fully when bedtime swings around.
If you’re not into napping, try Yoga Nidra instead— it’s weird but it works, and the body of science supporting it is only growing. You’ll lie still, pass energy around your body and come out of it super refreshed.
Finally, if you didn’t know, orgasms are like nuclear knockout devices.
Don’t think I need to say much else here…
Sleep well! 😴