9 Evidence-Based Sleep Tips — Full Breakdown & Transcript

[00:00] So over the last few months,

[00:00] I've interviewed a bunch of sleep experts

[00:02] and listened to loads of podcasts

[00:03] and read loads of books

[00:04] all about the science behind effective sleep.

[00:07] And these are the nine evidence-based things

[00:09] that I've built into my routine

[00:10] to help me get an amazing night's sleep

[00:11] and feel well rested throughout the day.

[00:13] Let's get started.

[00:14] First off, I try to sleep

[00:15] for around seven to eight hours each night.

[00:17] Now the science on how long you should sleep for

[00:18] isn't straightforward,

[00:19] but most research says that between seven

[00:21] and nine hours of sleep at night

[00:22] is ideal for a healthy adult.

[00:24] And according to a big 2015 study

[00:26] by the American Academy of Sleep Science

[00:27] and the Sleep Research Society,

[00:29] "adults should sleep seven or more hours per night

[00:31] because regularly getting less than seven hours of sleep

[00:33] can lead to a load of bad stuff like weight gain

[00:35] and heart disease and depression

[00:37] and charmingly increased risk of death."

[00:38] If you're not sure if you should sleep seven

[00:40] or eight or nine hours,

[00:41] then the solution is pretty simple.

[00:42] Just experiment with how much sleep you need

[00:44] to feel happy and productive the next day.

[00:46] And remember, if you get too obsessed

[00:47] with getting eight hours of sleep every single night,

[00:49] that actually might spike your stress levels,

[00:51] ironically making it more difficult to get to sleep.

[00:53] And this is called sleep anxiety.

[00:55] So the second thing I try to do for healthy sleep

[00:56] is to build a sleep rhythm.

[00:58] I set a regular time for going to sleep and waking up

[01:00] and I try my best to actually stick to it.

[01:02] So for example, I usually go to sleep

[01:03] around 11 or 11.30 PM and get up around 7 AM.

[01:07] The more consistent your rhythm,

[01:08] the easier it's gonna be to fall asleep and to wake up.

[01:10] And this is because of the homeostatic sleep drive,

[01:12] one of the main systems in our body

[01:13] that determines when we feel tired and when we feel awake,

[01:16] which is powered by the chemical "Adenosine".

[01:18] See, adenosine makes us feel this intense need for sleep.

[01:20] From the moment we wake up in the morning,

[01:22] adenosine starts building up in our body

[01:24] until eventually we start feeling sleep hungry.

[01:26] The more adenosine we have, the sleepier we feel.

[01:28] When we actually do get enough sleep,

[01:30] that drives our adenosine levels down again

[01:32] and we wake up feeling well rested.

[01:33] Okay, so why does this mean we should have consistent times

[01:36] for waking and sleeping?

[01:37] Well, if we start going to sleep and waking up

[01:38] at the same time every day

[01:39] and get our proper seven to eight hours of sleep,

[01:41] then our adenosine levels will regularly peak

[01:43] at the same time each evening,

[01:44] making us feel properly tired and ready for bed.

[01:46] And after seven to eight hours of sleep,

[01:48] that adenosine will be low enough

[01:49] that we can wake up naturally

[01:50] without feeling too groggy or tired.

[01:52] So the more we can invest in building the steady rhythm,

[01:54] the more we can bring our sleep schedule in sync

[01:56] with the chemicals in our body

[01:57] and the less likely we are to feel weirdly awake at 2 a.m.

[02:00] and start playing video games.

[02:01] And here are four practical things

[02:02] that can help you build that rhythm.

[02:03] First, set an alarm for the same time every day

[02:05] to help you wake up consistently.

[02:07] Secondly, ignore the weekend.

[02:08] As far as your body is concerned,

[02:10] the weekend is just two days where you do your best

[02:12] to mess up your healthy sleep cycle.

[02:13] For me, I try to personally avoid lie-ins

[02:15] or having a different sleep schedule

[02:16] on Saturdays and Sundays,

[02:17] so I don't mess up this adenosine rhythm

[02:19] that I've been trying to build.

[02:20] Thirdly, try to phase shift your social life.

[02:22] Basically, try to schedule evening meetups with friends

[02:24] a little bit earlier in the day.

[02:25] The occasional late night is totally fine,

[02:27] I just try not to make too much of a habit of it.

[02:29] And the final tip is to actually listen to your body.

[02:31] Try not to push through that sleepy late evening feeling.

[02:33] That's the exact trigger we're working towards,

[02:35] which makes it easier to fall asleep.

[02:37] Okay, so the next thing I do to get a good night's sleep

[02:39] is to catch the morning sun when I wake up.

[02:40] That's because in addition to adenosine,

[02:42] there's a second system inside all of us

[02:44] that affects when we feel sleepy and when we feel awake,

[02:46] a kind of internal 24-hour clock

[02:48] called the circadian rhythm.

[02:49] Now, this system is mainly controlled

[02:50] from a master clock in our brain called the

[02:52] suprachiasmatic nucleus,

[02:54] which lives just above the roof of our mouth,

[02:56] and sends signals to the rest of our body

[02:57] about whether to feel sleepy or awake.

[02:59] The circadian rhythm generally looks like a wave,

[03:01] with our brain releasing the chemicals cortisol

[03:03] and epinephrine to drive our upward spike

[03:05] in alertness during the morning and the rest of the day,

[03:07] and melatonin driving the downward curve at night,

[03:10] making us feel like going to bed.

[03:11] And the number one thing that influences

[03:12] this circadian rhythm is light,

[03:14] particularly morning sunlight.

[03:15] When morning sunlight hits the retina in our eyes,

[03:18] it sends a message to our internal circadian clock

[03:20] to trigger that release of cortisol and epinephrine,

[03:23] which makes us feel awake and alert.

[03:24] Now, the sun doesn't need to be just

[03:26] peeking over the horizon,

[03:27] it just needs to be within a few hours of sunrise.

[03:29] And the sooner you can get it after waking up, the better.

[03:31] So in terms of my personal morning routine,

[03:33] I wake up, I grab some water, I take my medication,

[03:35] which in this case is finasteride

[03:37] and Heights supplement and probiotic.

[03:39] And then after having a shower,

[03:40] I'll normally go for a walk

[03:41] and I'll walk over to the local Pret-A-Manger,

[03:43] where I've got the Pret Coffee subscription,

[03:45] because that encourages me to actually

[03:46] get out of the house in the morning to grab my coffee,

[03:48] and that means I'm getting the morning sunlight

[03:50] and I've also delayed my caffeine consumption,

[03:52] more on that a little bit later.

[03:53] Now, other types of bright light

[03:54] can trigger our wake up mechanisms,

[03:56] but our brain responds best to the quality

[03:58] and amount of light that's coming from the sun

[04:00] when it's at a low solar angle.

[04:01] So on bright cloudless days,

[04:03] you should apparently stay outside

[04:04] for around 10 minutes after waking up

[04:06] to properly trigger your circadian clock.

[04:08] On cloudy days, it might take a bit longer, like 20 minutes,

[04:10] and if it's really overcast,

[04:11] it could take 30 minutes to an hour.

[04:13] But the main thing is that we don't wanna overthink this,

[04:15] perfect is the enemy of good,

[04:16] and just getting any amount of morning sunlight

[04:18] in the morning is actually great for our circadian rhythm

[04:20] and for our sleep quality.

[04:21] Now, there's a second reason it's important

[04:23] to get that morning sunlight,

[04:24] in that it sets our circadian clock on a timer

[04:26] to release the hormone melatonin

[04:28] from the pineal gland in our brain

[04:29] in about 12 to 14 hours time,

[04:32] which is gonna make us feel sleepy later that evening.

[04:34] So the earlier we get that morning sunlight,

[04:35] the sooner that clock starts counting down,

[04:37] and the sooner we start feeling sleepy in the evening.

[04:39] So if I wake up at 7 a.m. and then I go for a morning walk

[04:42] to get that strong burst of morning sun for about 10 minutes,

[04:45] I should start getting the sleepy signal from my brain

[04:47] between about 7 p.m. and 9 p.m. that night.

[04:50] But if I wake up later at 8 a.m., for example,

[04:52] the sleepy phase is gonna move forward

[04:54] to between 8 p.m. and 10 p.m.

[04:55] And before we continue,

[04:56] I wanna give a massive shout out

[04:57] to the Huberman Lab podcast.

[04:59] Andrew Huberman's podcast is absolutely sick,

[05:01] I listen to it all the time,

[05:02] and the episodes about sleep really helped me figure out

[05:05] all of this stuff around the evidence around sleep

[05:07] and helped inform a lot of the research for this video.

[05:08] So thank you, Andrew Huberman, and your team.

[05:10] Okay, next, let's look at what time

[05:11] we ideally wanna be exercising

[05:13] to get the best possible sleep.

[05:14] So sunlight is the most important thing to focus on,

[05:16] but exercise does release endorphins,

[05:18] which also make us feel happy and more awake.

[05:20] Now, in an ideal world,

[05:21] I would be doing weight training in the morning,

[05:23] but I personally find that if I go gym in the morning,

[05:25] then I kind of feel a bit groggy for the rest of the day,

[05:27] so I'm not a huge fan of that.

[05:28] Instead, I do my morning walk thing.

[05:30] This is a thing that I figured out with my health coach.

[05:32] He was like, you know,

[05:33] try and get some steps in in the morning,

[05:34] and it also doubles as an effect

[05:35] in that it gets me the morning sunlight as well.

[05:37] Now, if you can actually do some proper exercise

[05:39] in the morning, then according to Andrew Huberman,

[05:41] there is evidence that our body starts

[05:42] to develop this anticipatory circuit,

[05:45] expecting that hit of morning exercise,

[05:47] because it happened over the last few days,

[05:48] and getting us to wake up

[05:49] and feel ready for it to happen again.

[05:51] And that adds to that morning spike of energy that we want,

[05:53] and it sets us up for healthy sleepiness in the evening,

[05:56] because our body is gonna be tired

[05:57] and is gonna need sleep to recover from that training.

[05:59] Like, think about the last time you went

[06:00] for a really long hike or had a lot of exercise.

[06:03] You probably had a long, deep sleep that night.

[06:04] So we've talked about some of the stuff

[06:06] that I do in my morning routine so far,

[06:08] but one thing that I do that's unrelated to sleep

[06:09] is browse a cheeky newsletter called Morning Brew

[06:12] on my phone, who are very kindly sponsoring this video.

[06:14] Now, Morning Brew is a totally free,

[06:16] 100% free daily newsletter that's delivered

[06:18] every single day, Monday through Sunday,

[06:20] and it just takes a few minutes to read,

[06:22] and it gets you up to date on all of the interesting news

[06:24] from the world of business and finance and tech,

[06:26] which are three of the things that I care most about.

[06:28] And it's my favourite way to consume the news,

[06:30] because A, it doesn't take very long,

[06:31] and B, it's written in a dry, witty,

[06:33] kind of entertaining manner,

[06:34] unlike most other sources of news,

[06:36] which are kind of dry and kind of boring.

[06:37] And it's really useful for keeping up to date

[06:39] with the content creative business stuff

[06:40] that affects me personally,

[06:41] like for example, Zuckerberg recently rolling out

[06:43] Meta Verified, which I heard about

[06:45] because I read my Morning Brew newsletter.

[06:47] And it's been great for also keeping me up to date

[06:49] about what's going on with the whole AI stuff,

[06:50] because there's just too much going on,

[06:52] it's hard to keep track of it on Twitter,

[06:53] and so on Morning Brew, I get like a decent write-up

[06:55] of what Microsoft Edge is doing,

[06:57] and how ChatGPT is going,

[06:58] and like what's going on with Bing,

[07:00] and how it's just started making

[07:01] absolutely ridiculous statements.

[07:03] And it's just generally funny and interesting reading

[07:04] about this kind of stuff.

[07:05] So if you are interested in anything to do with business,

[07:07] or finance, or tech,

[07:08] or you just want an entertaining way

[07:10] to browse the news once a day,

[07:12] then there is no reason not to sign up to Morning Brew.

[07:14] It is completely free,

[07:15] and it takes less than 15 seconds to subscribe.

[07:17] So if you're interested,

[07:18] then head over to morningbrewdaily.com forward slash Ali,

[07:20] and then you can subscribe there,

[07:21] and you'll be supporting the channel along the way.

[07:23] That link is also in the video description,

[07:25] so thank you so much Morning Brew for sponsoring this video.

[07:27] All right, time to talk about a big topic, caffeine.

[07:29] Now, remember the chemical adenosine,

[07:31] which makes us hungry for sleep?

[07:32] Well, to actually make us feel sleepy,

[07:33] adenosine needs to get picked up by our adenosine receptors.

[07:36] And what caffeine does is act like an adenosine antagonist,

[07:39] blocking those adenosine receptors in our brain

[07:41] to stop the sleepy adenosine signal from being processed.

[07:44] So the caffeine keeps us alert and awake initially,

[07:46] but when the caffeine wears off,

[07:47] we get a caffeine crash as the blocked adenosine

[07:50] rushes through our receptors again,

[07:51] making us feel really tired.

[07:52] Now, I drink coffee every morning

[07:54] and around two to three times a day,

[07:55] but there are two things when it comes to caffeine timing

[07:58] that I find quite useful.

[07:59] Firstly, I try to avoid coffee

[08:01] for the first hour of the day.

[08:02] And the idea behind this is that it gives your body

[08:04] enough time to naturally clear the adenosine

[08:06] that's left behind in your system.

[08:08] And secondly, to get better quality of sleep,

[08:09] I try to avoid drinking coffee

[08:11] or any other caffeinated drinks too late in the day,

[08:13] specifically after around two to 3 p.m.

[08:16] Now, caffeine has a half-life of five to six hours,

[08:18] which is the time it takes for the caffeine levels

[08:19] in your system to drop by 50%,

[08:21] but it takes even longer than that,

[08:23] after drinking caffeine,

[08:24] for our adenosine to be working normally again.

[08:26] So to stop caffeine interfering with our sleep,

[08:28] Dr. Huberman reckons that we should avoid it

[08:29] eight to 10 hours before our normal bedtime.

[08:32] So stop drinking between 1 p.m. and 3 p.m.

[08:34] if your bedtime is 11 p.m.

[08:35] Matthew Walker, the author of Why We Sleep,

[08:37] is a bit more conservative

[08:38] and says aim for 10 to 12 hours.

[08:40] So basically only caffeine in the morning,

[08:41] but I personally stop around 3 p.m.

[08:43] Everyone has different caffeine tolerances though.

[08:45] Like some people can't drink any caffeine past 11 a.m.

[08:47] without it messing with their sleep.

[08:49] But for other people,

[08:50] the cutoff point is more like 4 p.m.

[08:51] There's a small percentage of people

[08:52] that can even have caffeine late at night

[08:54] and still fall asleep easily,

[08:55] but that probably still affects their sleep quality,

[08:57] even if they get technically a full night's sleep.

[08:59] And by the way, if you're enjoying this video so far,

[09:01] I'd love it if you could drop a little thumbs up

[09:03] on the thing, apparently it really helps us

[09:04] for the algorithm.

[09:05] Now, this is potentially getting a bit overboard,

[09:06] but the sixth thing that I try to do every day

[09:08] is to go outside around an hour or so before sunset

[09:12] and get a good 10 to 30 minutes of evening sunlight.

[09:14] So the sunlight trick that we talked about earlier

[09:16] works in reverse.

[09:17] When the light-sensitive melanopsin neurons in your eye

[09:20] detect the specific colour and intensity

[09:22] of evening sunlight,

[09:23] they send a signal to your circadian clock

[09:25] that it's getting to the end of the day

[09:26] and that sleep is coming.

[09:27] Again, try to be in direct sunlight if at all possible

[09:29] because windows and other kind of barriers like sunglasses

[09:31] make the sunlight a lot less effective.

[09:33] So if you get the sun in the morning and in the evening,

[09:35] you give your internal clock consistent light anchors,

[09:38] making it way easier to get into a healthy rhythm

[09:40] of waking up and going to sleep at the same time every day.

[09:43] All right, so now it's evening.

[09:44] And for me, I try my very best not to expose myself

[09:47] to artificial lights after around 8 p.m.

[09:49] And I try to avoid viewing bright lights

[09:51] between 10 p.m. and 4 a.m.,

[09:53] including my laptop screen and my computer monitor

[09:55] and my phone.

[09:56] The reason we wanna avoid light

[09:57] is because bright artificial lights

[09:59] mimic the effect of bright light.

[10:03] and releases cortisol and epinephrine that keeps us awake.

[10:06] And being awake in the evenings

[10:07] is exactly what we want to avoid.

[10:08] Now, scarily, the longer that we've been awake,

[10:10] the more sensitive we are to bright lights,

[10:11] making us feel even more awake.

[10:13] So the later it gets in the evening, the higher the stakes.

[10:15] In fact, this 2018 study,

[10:16] which was published in the journal Cell,

[10:18] which is a high quality journal,

[10:19] showed that light arriving to the eyes

[10:20] between 11 p.m. and 4 a.m. even suppresses dopamine,

[10:23] the thing that makes us feel good,

[10:25] and is a natural antidepressant.

[10:26] And it also activates the habenula,

[10:28] the disappointment nucleus in our brain.

[10:30] And so over the next few days, this lowers our mood

[10:32] and makes us feel more disappointed

[10:33] and actually can make it harder to learn new things.

[10:35] So for me personally, the way that I avoid all these lights

[10:37] is I try to avoid going on the computer beyond 10 p.m.

[10:40] If I am on the computer,

[10:41] I try and dim the brightness setting on my computer down.

[10:44] I try and use the kind of flux night mode display setting

[10:47] on the Mac to try and avoid the blue light

[10:49] that comes in from the computer screen.

[10:50] I also try my best to avoid using my phone at nighttime.

[10:53] And instead I use my Kindle,

[10:54] which is generally on a fairly dim,

[10:56] dark mode, warm light setting.

[10:57] Now, apparently the positioning of these artificial lights

[10:59] can make a difference

[11:00] because we're particularly sensitive to overhead lights

[11:02] because we've evolved to detect the light from the sunlight.

[11:05] And so having warm lights that are positioned low,

[11:06] like lamps and candles that are low down,

[11:09] instead of having the ceiling lights on,

[11:11] apparently can make a difference

[11:12] to how effective our sleep can be.

[11:13] Okay, a really quick tip here.

[11:14] I always expect to feel alert

[11:16] around one hour before my natural bedtime.

[11:18] And I know that if I just read a book

[11:19] and stick to my normal habits,

[11:20] then I'll eventually feel sleepy again.

[11:22] Now, this is totally normal.

[11:23] And according to Dr. Hiberman's podcast,

[11:25] this is a naturally occurring spike in wakefulness.

[11:27] So don't freak out if it happens, it's gonna pass.

[11:29] Now, the final step in my sleep routine

[11:31] is keeping the room where I sleep nice and cool.

[11:33] Now, our bodies need a drop in temperature

[11:35] by one to three degrees to fall asleep

[11:37] and to stay asleep effectively.

[11:38] So here's what I do personally.

[11:39] Firstly, if I'm in a hotel room or anything

[11:41] that has air conditioning and thermostat,

[11:42] I generally set it quite low.

[11:44] Some people say that 19 degrees Celsius is the ideal.

[11:46] I find that that's still a bit warm for me.

[11:48] And I like to set it at like 16, 17 degrees if I can.

[11:50] In my own home, I don't have air conditioning.

[11:52] And so I'll sometimes open the windows

[11:54] if it's particularly warm in the room

[11:55] and I'll use a fan if it's particularly hot.

[11:57] Plus I like the white noise of the fan

[11:58] which helps me fall asleep.

[11:59] And this one's a bit extra,

[12:00] but I do also happen to have an Eight Sleep mattress.

[12:02] I interviewed the founders of Eight Sleep

[12:04] on my podcast a little while ago.

[12:05] We talked a lot about sleep.

[12:06] I'll link that episode down below

[12:07] if you wanna check it out.

[12:08] But the Eight Sleep mattress

[12:09] is basically like a mattress topper thing

[12:10] that has a liquid cooling system in it.

[12:12] And so I usually have that set to the colder setting.

[12:15] Honestly, something like that is pretty overkill.

[12:16] You really don't need it.

[12:17] It's pretty expensive.

[12:18] You can just leave a window open

[12:19] or just get a cheap ass fan

[12:20] just to cool your body down

[12:22] to the temperature that it needs to be.

[12:23] And some people find that having a hot bath

[12:24] or a hot shower before bed really helps

[12:26] because it helps reduce your internal body temperature.

[12:28] So if you incorporate each of these nine science-backed tips

[12:31] for my routine,

[12:32] your day might look something like this.

[12:33] You'd have a regular bedtime and waking time

[12:35] so you'd get around seven to eight hours of sleep.

[12:37] You'd view the sun just after you get up

[12:39] and maybe do some exercise as well.

[12:41] You'd delay your caffeine consumption

[12:42] for around an hour after waking up

[12:44] and you'd stop drinking caffeine

[12:45] after around two or 3 p.m.

[12:47] You might go for a walk and view evening sunlight

[12:49] for about 10 minutes just before sunset.

[12:51] You would dim all of your house lights

[12:52] just a few hours before bed and avoid any bright screens.

[12:55] You'd try and ride out any spike in energy

[12:56] before your bedtime.

[12:58] And finally, you'd keep your bedroom cool

[12:59] so that you can fall asleep easily.

[13:01] Now, I'll be honest,

[13:02] I don't do all of these things every day.

[13:03] I try my best to stick to them,

[13:05] but I don't beat myself up if I have a little bit of a lie

[13:07] or if I have coffee a little bit too early in the morning

[13:09] or a little bit too late in the day.

[13:10] And if you go to this video,

[13:11] you might like to check out this video over here,

[13:13] which is a video about

[13:14] why you might find yourself always tired.

[13:16] And it's about seven myths that are ruining your sleep.

[13:18] And so with this video and that video,

[13:19] that's basically everything you need to know

[13:21] to have a fantastic sleep routine.

[13:22] Thank you so much for watching.