수면 최적화 비법과 방법 정리 | 과학 기반 실전 가이드

- Welcome to The Huberman Lab Podcast, where we discuss scienceand science-based tools for everyday life.

 [bright music] I'm Andrew Huberman and I'm a professor ofneurobiology and ophthalmology at Stanford School of Medicine.

 Today we're talking all about sleep and how to optimize your sleep.

 This is a topic we've coveredpreviously on this podcast in the episode called "Master Your Sleep.

" However, since the airing of that episode, there's been some terrificnew science to come out.

 I've also received thousands, yes, literally thousands of questions related to the specificprotocols covered in that episode as well as in the episodeon jet lag and shift work.

 And while today's episode is not specifically aboutjet lag and shift work, we are going to cover tools that will allow you to shift your schedule if you need to for work or travel, and we will also cover tools that will allow you to fall back asleep if you happen to wake upin the middle of the night or if you get a poor night's sleep, how to actually recover from that poor night's sleep more quickly, and yes, indeed, even replacesleep that you've lost.

 So today's episode is going to be filled with practical tools.

 We will touch on some ofthe underlying science, but it's really designedto be a practical toolkit for optimizing your sleep depending on your specific sleep needs.

 Various times throughout today's episode, I will refer to studies thatform the backbone of the tools that I'll be describing.

 But whereas most of thepodcast episodes here tend to be deep scientificmechanism and then tools, scientific mechanism, then tools, today I'm mainly going tofocus on the practical tools that anyone, indeed, allpeople, I believe, should use in order to optimize their sleep.

 Why should everybody wantto optimize their sleep and put considerable effortinto optimizing their sleep? Well, put simply, sleep is the foundation of mental health, physical health, and performance of all kinds, cognitive performance, physicalperformance, et cetera.

 It also controls thingslike our immune system, wound healing, our skinhealth and our appearance, whether or not we canthink clearly or not, whether or not we will live as long as we possibly can or not, whether or not we suffer from dramatic age-relatedcognitive decline or not.

 In other words, whether or notwe keep our memory as we age.

 I could go on and on about all the terrible thingsthat can happen to somebody if they don't sleep well.

 Thanks to the great workof Professor Matt Walker at University of California, Berkeley, and the wonderful book thathe wrote, "Why We Sleep," I think the world is largely onboard now that sleep is critical to our health, our mental health, our physicalhealth, and our performance, but what's not often discussedis how great life is, that is, how much morefocused and energetic and how positive our mood gets, when we are sleeping for theappropriate amount of time at the appropriate depth and when we are doing that regularly.

 Basically everything in life gets better when we're sleeping well.

 So today I'm going to teach you the tools that will allow you tooptimize your sleep.

 That is, get to sleep and stay asleep, fall back asleep if you wakeup in the middle of the night, and adjust your sleep given the various life demandsyou may be experiencing.

 I'm pleased to announce thatThe Huberman Lab Podcast is now partnered withMomentous supplements.

 We partnered with Momentousfor several important reasons.

 First of all, they ship internationally, because we know thatmany of you are located outside of the United States.

 That's valuable.

 Second of all, and perhaps most important, the quality of theirsupplements is second to none, both in terms of purity and precision of theamounts of the ingredients.

 Third, we've really emphasized supplements that are single-ingredient supplements and that are supplied in dosages that allow you to build asupplementation protocol that's optimized for cost, that's optimized for effectiveness, and that you can add things and remove things from your protocol in a way that's reallysystematic and scientific.

 This is really hard to do if you're taking blendsof different supplements or if the dosages are suchthat you can't titrate, or that is, adjust thedosages of a given supplement.

 So by using single-ingredient supplements, you can really buildout the supplement kit that's ideal for youand your specific needs.

 If you'd like to see the supplements that we partner with Momentous on, you can go to livemomentous.

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 There you'll see those supplements.

 And just keep in mind thatwe are constantly expanding the library of supplementsavailable through Momentous on a regular basis.

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 Before we begin, I'd like to emphasize that this podcast is separate from my teaching andresearch roles at Stanford.

 It is, however, partof my desire and effort to bring zero-cost-to-consumer information about science and science-related tools to the general public.

 In keeping with that theme, I'd like to thank thesponsors of today's podcast.

 Our first sponsor is InsideTracker.

 InsideTracker is apersonalized nutrition platform that analyzes data from your blood and DNA to help you better meet your health goals.

 I've long been a believer ingetting regular blood work done for the simple reasonthat many of the factors that impact your immediateand long-term health can only be analyzed froma quality blood test.

 And nowadays, with theadvent of modern DNA test, you can also get insight into, for instance, whatyour biological age is and compare that toyour chronological age.

 And, of course, your biological age is really the age that counts.

 The problem with a lot of blood tests and DNA tests out there, however, is that you get information back about the levels of metabolic factors, lipids, hormones, et cetera, but you don't know what todo with that information.

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 They have a personalized platform.

 So this is a web portal where you can go, you'll see the numbers fromyour blood tests and DNA tests, and then it will tell you, for instance, how you could adjust variousaspects of your nutrition or your exercise or supplementation in order to bring those numbers into the ranges that are best for you.

 If you'd like to try InsideTracker, you can go to insidetracker.

com/huberman to get 20% off any ofInsideTracker's plans.

 That's insidetracker.

com/hubermanto get 20% off.

 Today's episode is alsobrought to us by Eight Sleep.

 Eight Sleep makes smart mattress covers with cooling, heating, andsleep tracking capabilities.

 It turns out that your body temperature and your ability to fall and stay asleep are very closely related.

 If your body does not dropby one to three degrees, you are simply not goingto get into deep sleep or stay in deep sleep.

 And waking up, it also turns out, is related to body temperature.

 Every time you wake up in the morning, your body is warming upin order to wake you up, and this has an enormous numberof hormonal and metabolic and other cascades thatare vitally important, not just to what happens while you sleep, but your health and your energy and focus throughout the day.

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 If you've been sleeping pretty well but waking up in the middle of the night, you might also find that by cooling your mattress even further toward the middle of your sleep about, well, you'll stay indeep sleep much longer.

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 Today's episode is alsobrought to us by LMNT.

 LMNT is an electrolyte drinkthat has everything you need in order to get your brain andbody to function at its best, but none of the things you don't, in particular, sugar.

 Electrolytes are vitally important to the way that your neurons,your nerve cells, work and, indeed, to the way that all the cells of your body work.

 But your nervous system and your neurons particularly depend on electrolytes because you need the electrolytes, sodium, magnesium, and potassium, in the proper ratios, in order for those nerve cells to fire what are called action potentials, which are the electrical signals that allow your neurons to work and to allow you to do everything from remembering information to moving your muscles deliberately.

 When you exercise, or even if you don't, you can get quite low on electrolytes, especially on a hot day.

 You can get dehydrated.

 There are lot of different ways to replenish your fluids and electrolytes and there are a lot of different electrolyte drinks out there, but many of them contain a lot of sugar.

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 Let's talk about sleep andtools to optimize your sleep.

 I want you to conceptualize yourself as contained within a room that has only very few windowsor very few entry points.

 What do I mean by this? Well, your brain and yournervous system control whether or not you move or don't move.

 They control whether ornot you're digesting food or you're not digesting food.

 They control whether or notyou're stressed or not stressed, happy or sad, et cetera.

 All of that stuff thatcontrols all that stuff is housed inside yourskin and skull, et cetera.

 That might seem pretty obvious, but what that means is thatfor your brain and body to feel alert and focused, ready to move andexercise or do some work, or if your brain body are goingto lie down and go to sleep, well, that brain and bodyneeds cues, it needs inputs, to determine when to dothose different things.

 And those cues and inputs arrive through a defined set ofwhat I'll call stimuli, but you can also think ofthese as levers or tools.

 The main levers and toolsthat are going to allow you to control when you areawake and when you are asleep and to get better sleep every single night are light, literallyphotons, light energy, could be from sunlight, couldbe from artificial light, we will discuss thoseparticulars in a moment, as well as darkness.

 That is the absence of light.

 So we've got light and dark.

 Those are two very powerful tools to encourage your nervous system to be in one state or another, meaning awake or asleep.

 Temperature is another tool or lever.

 Turns out that when yourbody is cooling down, you have a greater tendencyto fall and stay asleep.

 In fact, every nightwhen you actually sleep, your body is droppingby one to three degrees and that drop in temperature is required.

 It's like a gate that yourbody has to go through in order for you to get into sleep.

 And in fact, the converse is also true.

 If your body heats up byone to three degrees or so, you will wake up.

 So you've got light,dark, temperature, food.

 And when we say food, we mean what we eat, when we eat, and the amount that we eat.

 Okay, so light, dark,temperature, food, exercise.

 And of course, exercisecomes in different forms.

 We can do cardiovascular exercise that can be low-intensity,long-distance exercise.

 It can be high intensity, so-called high intensityinterval training.

 It could be weighttraining.

 It could be yoga.

 It could be swimming, anynumber of different activities.

 But exercise, in general, causes an increase in body temperature and tends to make us more alert, not just during the exercise, but in the immediatehours after that exercise.

 Exercise does some other things that relate to our sleep as well and we'll talk about those today and how you can leverage them.

 Another potent lever for adjusting your sleepinessand wakefulness is caffeine.

 This, of course, comesas no surprise to people, but why and how caffeine worksmight come as a surprise.

 Very briefly, we have a molecule in our body called adenosine and the longer we have been awake, the more adenosine buildsup in our brain and body and adenosine is part of thereason why we get sleepy.

 Caffeine effectively operatesas a adenosine antagonist.

 It works by basically occupyingthe receptor for adenosine.

 So it's a little bit ofa convoluted mechanism.

 But basically all you need to know is that caffeine preventsthe actions of adenosine.

 That's one of the reasons whycaffeine makes us feel alert.

 But how much caffeine we drink and when we drink caffeine turnsout to be vitally important for adjusting our wakefulness and for optimizing our sleep.

 So we'll talk about that as well.

 The other category of lever or tools which are immensely powerfulfor optimizing sleep are supplements.

 There now exist as many aseight different supplements that can powerfully modulatesleep in healthy ways and that have huge margins for safety.

 So we're going to talk aboutwhat those supplements are.

 In previous episodes of this podcast and as a guest on other podcasts, I've talked about threeparticular supplements, magnesium threonate,apigenin, and theanine, which together can really enhance the speed at which one falls asleep and people's ability to stay asleep and to really get intothose deep stages of sleep that are particularly restorative.

 Today we're going totalk a little bit more about each of those three and how they can bestbe used in combination, but we are also going to touchon some other supplements that I have not talked aboutmuch before, if at all.

 Things like glycine andGABA, as well as inositol.

 Many people are going tofind inositol interesting and of particular use to them, especially if they're followinga low-carbohydrate diet or if they are fasting before sleep or just trying to avoideating too close to bedtime and yet they're having ahard time falling asleep.

 Inositol also turns outto be especially useful for people who have a tendency to wake up in the middle of the night and have a hard time falling back asleep.

 It also has some interestingand potent effects on anxiety throughout the day.

 So we're going to talk aboutinositol as a tool as well.

 And then last in our listof general categories of levers and tools for optimizing sleep are digital tools.

 Now, when we say digital tools, I don't necessarily mean devices.

 What I mean are things likenon-sleep deep rest scripts.

 These are zero-costscripts that you listen to that take your body throughsome deep relaxation and that can help people bothfall asleep, stay asleep, fall back asleep, andget better at sleeping.

 And also going to talk about digital tools related to self-hypnosis.

 This is distinctly differentfrom stage hypnosis.

 So I know some of you hearhypnosis and you think, oh, you know, peopleclucking like chickens and doing things that areoutside their control.

 That's not at all whatI'm referring to here.

 I'm talking about clinicallyand research-supported tools that have been shown toenhance people's ability to fall and stay asleep and that can get youfar better at sleeping.

 So again, to recap thelist of levers and tools, we've got light and dark, and that includes the intensity of light, the timing of light, et cetera.

 We've got temperature.

 We have food.

 We have exercise, caffeine,supplements, and digital tools, not just limited to devices, but zero-cost tools thatyou can access on YouTube and elsewhere in various apps that can really helpyou optimize your sleep.

 So today we're going totalk about all of these.

 I really want to provide youas many tools as possible, give you the logic behindeach of those tools and when and how best to apply them so that you can develop the sleep toolkit that's ideal for your sleep needs.

 As we head into our description of tools for optimizing sleep, let's consider what theperfect 24-hour cycle would look like.

 Let's start this 24-hour cycle with when you wake up in the morning.

 So for some of you, that will be 5:00 a.

m.

 For others of you, that will be 10:00 a.

m.

 Most people, I believe, wake up sometime between 6:30 a.

m.

 and 8:30 a.

m.

 But regardless of when youwake up in the morning, one of the first things that happens is that your bodytemperature is increasing and that's just going to happen naturally.

 Some of it is going to be the consequence of your moving around a bit, but really the increasein body temperature is one of the main triggers for why you woke up in the first place.

 That increase in body temperaturein turn causes an increase in the release of ahormone called cortisol.

 Cortisol is often discussedas a stress hormone, but it's not just associated with stress.

 It also enhances your immune system provided cortisol iselevated at the right times, and the right time forcortisol to be elevated is when you first wake up in the morning.

 That increase in cortisol is also going to increase metabolism.

 It's also going to increaseyour ability to focus mentally and for you to move your body.

 So again, cortisol is often demonized and consider this bad thing.

 And indeed, you don't want cortisol to be chronically or consistently elevated throughout the day or night.

 But you do want cortisol toreach its peak early in the day right about the time you wake up.

 One way that you can ensure that that cortisol peakoccurs early in the day right about the time that you wake up is to view bright light,ideally from sunlight, within the first 30 to60 minutes after waking.

 That's right, view bright sunlight within the first 30 to60 minutes after waking.

 I'll get into all the caveats about what happens if youwake up before the sun is out, what if you live in theUK where there is no sun, or people claim there is no sun.

 Hate to tell you this, folks,but there is sun in the UK.

 We'll talk about all that.

 But everybody, whether or notyou live in a cloudy place or a sunny place, whether or not there'scloud cover or not that day, should really strive to getbright light in your eyes, ideally from sunlight, within the first 30 to60 minutes after waking.

 The reason for that is very simple.

 You want to trigger that cortisol increase to occur very early in your day, and you don't want thatcortisol peak to happen later, which is what will happen if you wait to getoutside and see sunlight.

 The reason for this is that you have a set ofneurons, nerve cells, in your eye.

 They're calledintrinsically photosensitive melanopsin cells, but you do not need to know that name.

 Those neurons respondbest to bright light, and especially right afterwaking early in the day, they are best able tosignal to a set of neurons that reside over the roof of your mouth called the suprachiasmatic nucleus, which is a cluster of neurons that then sends a hugenumber of other signals, electrical and chemical, out to your entire body that triggers that cortisol increase, provides a wake-up signalfor your brain and body, and sets in motion a timer for you to fall asleep later that night.

 So again, we're not trying to go into too much mechanism today.

 We are trying to really hammer on tools and I'll substantiate those tools just a bit with some mechanism.

 But here's what you do, orat least here's what I do.

 I wake up in the morning andI want to reach for my phone, but I know that even if I wereto crank up the brightness on that phone screen, it's not bright enough totrigger that cortisol spike and for me to be at mymost alert and focused throughout the day and to optimize my sleep at night.

 So what I do is I get outof bed and I go outside.

 And if it's a bright, clear day and the sun is low in the sky or the sun is, you know,starting to get overhead, what we call low solar angle, then I know I'm gettingoutside at the right time.

 If there's cloud coverand I can't see the sun, I also know I'm doing a good thing because it turns out,especially on cloudy days, you want to get outside and get as much light energyor photons in your eyes.

 But let's say it's a very clear day and I can see where the sun is.

 I do not need to staredirectly into the sun.

 If it's very low in thesky, I might do that because it's not going tobe very painful to my eyes.

 However, if the sun isa little bit brighter and a little bit higher in the sky, sometimes it could be painful to look at.

 So the way to get this sunlightviewing early in the day is to look toward the sun.

 If it's too bright to look at directly, well, then don't do that.

 You just look toward it,but not directly at it.

 It's absolutely fine to blink.

 In fact, I encourage you to blink whenever you feel the impulse to blink.

 Never look at any light,sunlight or otherwise, that's so bright thatit's painful to look at 'cause you can damage your eyes.

 But for this morning sunlight viewing, it's best to not wear sunglasses, that's right, to not wear sunglasses, at least for thismorning sunlight viewing.

 It is absolutely fine to weareyeglasses or contact lenses, so-called corrective lenses.

 In fact, those will serve you well in this practice or this tool because they will focus thelight onto your neural retina and onto those melanopsin intrinsically photosensitiveganglion cells.

 If your eyeglasses or contact lenses have UV protection, that's okay.

 There's so many differentwavelengths of light coming from the sun and they are bright enough that they will trigger the mechanisms that you want triggeredat this early time of day.

 So try and get outside, ideally within the firstfive minutes of waking or maybe it's 15 minutes, but certainly within thefirst hour after waking.

 I want to share with youthree critical things about this tool ofmorning sunlight viewing.

 First of all, this is notsome woo biology thing.

 This is grounded in thecore of our physiology.

 There are literallyhundreds, if not thousands, of quality peer-reviewed papers showing that lightviewing early in the day is the most powerful stimulus for wakefulness throughout the day and it has a powerful, positive impact on your ability to falland stay asleep at night.

 So this is really thefoundational power tool for ensuring a great night's sleep and for feeling more awake during the day.

 Second of all, if you wakeup before the sun is out, you can, and probably should,flip on artificial lights in your internal homeenvironment or apartment or wherever you happen to live if your goal is to be awake, right? If you wake up at four in the morning and you need to be awake, well, then turn on artificial lights.

 Once the sun is out, however, once the sun has risen, then you still want to getoutside and view sunlight.

 Some of you will wake upbefore the sun comes out.

 And if you're asking whether or not turning on artificial lights can replace sunlight at those hours, unfortunately, the answer is no.

 Unless you have a very special light, and we'll talk about what kind of light, the bright artificial lightsin your home environment are not, I repeat, are notgoing to be sufficiently bright to turn on the cortisol mechanism and the other wake-up mechanisms that you need early in the day.

 The diabolical twist, however, is that those lights inyour home or apartment or even on your phone are bright enough to disrupt your sleep if you look at them too late at night or in the middle of the night.

 So there's this asymmetry inour retinal, our eye biology, and in our brain's biology, whereby early in theday, right around waking, you need a lot of light, a lot of photons, a lot of light energy, and artificial lightsgenerally just won't accomplish what you need them to accomplish.

 But at night, even a littlebit of artificial light can really mess up yourso-called circadian, your 24-hour clocks, and all these mechanismsthat we're talking about.

 So if you wake up before thesun is out and it's still dark, please turn on as manybright artificial lights as you possibly can or need, but then get outside once the sun is out.

 On cloudy days, you especiallyneed to get outside.

 I repeat, on cloudy days, overcast days, you especially need to getoutside and get sunlight.

 You just need to get more of it.

 Now, how much light and howmuch light viewing do you need? This is going to varydepending on person and place, literally where you live on earth, whether or not there'sa lot of tree cover, whether or not you're somebodywho has sensitive eyes or less sensitive eyes.

 It's really impossible for me to give an absolute prescriptive, but we can give some general guidelines.

 In general, on a clear day, meaning no cloud coveror minimal cloud cover, you want to get this sunlightexposure to your eyes for about five minutes or so.

 Could be three minutes one day, could be seven minutes the next day, about five minutes.

 On a day where there's cloud cover, so the sun is justpeeking through the clouds or it's more dense cloud cover, you want to get about 10minutes of sunlight exposure to your eyes early in the day.

 And on days that arereally densely overcast or maybe even are rainy, you're going to want to getas much as 20 or 30 minutes of sunlight exposure.

 Another key thing is do not, forget about, just don't try and getthis sunlight exposure through a windshield of a car or a window, whether or not it's tinted or otherwise.

 It takes far too long.

 It's simply not going totrigger the relevant mechanisms.

 You would be standing there all day trying to get enough light into your eyes from the morning sunlight and by then the sunwill have already moved from low solar angle to overhead and it simply won't workfor all sorts of mechanisms related to your circadianrhythm functions.

 So just don't try and do it through a windshield,sunglasses, or a window.

 It's just not going to work.

 Get outside.

 If the weather is really bad or for whatever reason, safety reasons, you cannot get outside, well, then I suppose tryand get near a window.

 That would be the last, last resort.

 But you really want to get outside to get this sunlight exposure.

 Now, if you live in a part of the world where it's extremely dark and overcast or the weather won't let you outside or you live in a caveor some other small box that does not allow anynatural light into it for whatever reason, well, then you're goingto need a replacement for that sunlight.

 And there are sunlightsimulators or daylight simulators that you can purchase.

 Those are quite expensive in general and therefore I suggest cheaper options that work just as well because they get just as bright.

 Things like ring lights that are sold in order for people to takeselfies and this kind of thing.

 A drawing LED tabletwill work pretty well.

 I actually have one of those and I put it on my desk all morning even though I still getoutside and look at sunlight first thing in the morning, again, also, especially, Ishould say, on cloudy days.

 We do not have any affiliation to any ring lights or LEDlights or these panels.

 So we will provide a link toa couple of different options if you want to explorethe various options.

 I don't know what people'sdifferent budgets are.

 I don't know where people live.

 I just know that manyof our listeners live in locations throughout the world where, for instance, during the winter, it gets very, very dark, so they can't get sufficient sunlight.

 But get that morning light,ideally from sunlight, and take into accountall the specific points that I've given you here.

 And, I should say, enjoy this practice.

 It's really nice to get outsidefirst thing in the morning and get this sunlight.

 In fact, when you start doing this, you'll notice that your body will start to feel more energized and it will feel moreenergized more quickly.

 You'll actually start to notice this mechanismkicking in each day, especially if you're payingattention to your physiology.

 So enjoy this practice of getting outside.

 Yes, you can take yourmorning beverage outside.

 Yes, you can take your dog with you.

 In fact, animals intuitively know to get this morning sunlight.

 They actually seek it outat the right times of days.

 We human beings need to be told by podcasters and other people about the science that supportsthese kinds of practices.

 Our pets apparently do not.

 But get outside alone or with somebody, with your kids, with your dog.

 However you go about this practice, make sure you do this practice at least 80% of the days of your life.

 That's right.

 If you miss a day, for instance, you're bedridden for a day, try and get next to a window.

 Let's say you are traveling, or for whatever reason, you are not able to get outsidefirst thing in the morning, well, then try to get twiceas much sunlight in your eyes, or I should say extend the duration of sunlight viewing in the morning for twice as long the following day.

 This is a slow, integrative mechanism that underlies this whole thing of wakefulness during the day and sleep at night due to sunlight viewing and if you miss a day, you canmake up for it the next day, but you have to get twice as much light or twice as much duration of light.

 If you really want to get technical and you really want to measure how much light is in your environment, you can download a free app,something like Light Meter, and that will allow your phone to act as a bit of a light meter.

 It'll give you a prettyaccurate measurement of how many lux, which isa measure of brightness, are in your environment in the morning.

 And in general, that's justgoing to be a good tool for evaluating your environments.

 Here's what I suggest you do.

 Wake up in the morning, take Light Meter, point it at the brightestlight in your home, and take a measurement, and what you'll probably findis it's about a thousand lux.

 Now go outside and ifthere's some sunlight out and there's cloud cover, point it at the sky and press that button.

 You can actually hold it down and it'll give you a dynamicallyupdated lux measurement.

 And what you'll findis like 5,000, 10,000, sometimes even 90,000 lux, even though you don't experienceit as so much brighter, and that's because anindoor artificial light is very concentratedover a small spatial area whereas the sunlight is very diffuse.

 But it's that diffuse,very bright sunlight, that photon energy, that you really want that's going to set all therhythms of your brain and body in the proper way.

 Not just that cortisol peak, but it's going to triggerproper metabolism, it's going to set a timer for you to be able to fall asleepabout 16 hours later, and on and on and on.

 And I should mention withinthe on and on and on, it's also going to suppress any melatonin, a hormone that makes you sleepy that happens to be swimmingaround in your bloodstream at the time you wake up.

 It does a number of other things too, including interact withthe adenosine system and kind of wash out some of the adenosine that might still be residualif you didn't sleep enough.

 Fundamentally speaking, getthat morning sunlight viewing.

 I promise you will begrateful that you did.

 It makes everybody feelbetter, feel more alert, and it will greatlyassist with your ability to fall and stay asleep later that night.

 Before we continue withtoday's discussion, we're going to take a brief pause to acknowledge our sponsor, Athletic Greens, also called AG1.

 I started taking AthleticGreens way back in 2012.

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 It essentially covers allof my nutritional bases.

 And the probiotics inparticular are important to me because of the critical importance of what's called the gut-brain axis, that is neurons and othercell types in the gut, in the digestive tract, that communicate with the brain and the brain back to the digestive tract in order to control things like mood, immune function, hormonefunction, and on and on.

 Whenever somebody has asked me what's the one supplementthey should take, I always answer Athletic Greens.

 I gave that answer longbefore I ever had this podcast and it's the answer I still give now for all the reasons that Idetailed just a moment ago.

 If you'd like to try Athletic Greens, you can go to athleticgreens.

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 Okay, so now we're still focusing on this early part of theday when you've woken up, the first hour or so after waking.

 And we can go to our list ofother levers and tools, right? We have light and dark.

 We already talked about lightand sunlight in particular.

 We've got temperature, food, exercise, caffeine, supplements, and digital tools.

 Now, once you've woken up andyou want to be awake, okay? So this is likely to be early in the day if you're following amore standard schedule.

 You will also want toleverage not just light, but temperature as a tool.

 If you are inclined, it would be wise to try and increase yourcore body temperature a bit more quickly than it would otherwise if you were to just, youknow, shuffle around outside, get your sunlight, maybe read a little bit, et cetera, and there are two mainways you can do that.

 The first way is to get intocold water of some sort.

 So this could be a cold shower of anywhere from one to three minutes.

 This could be an ice bathif that's your thing.

 It could be a cold tub, or if you own a cold tub that's specifically designedfor deliberate cold exposure.

 Get under some cold water.

 That will certainly wake you up.

 And if you've ever jumped into cold water or had a cold shower, you know it really wakes you up because you releaseadrenaline, epinephrine, from both your brain and body, the body from your adrenals and your brain from alittle cluster of neurons called locus coeruleus.

 Again, the names don't matter.

 One to three minutes of coldwater exposure will wake you up because of that adrenaline release and, and I want to highlight the and, it will serve to increaseyour core body temperature.

 That's right, your body and brain interact as a bit of a thermostat system where if you put something coldon the surface of your body, your brain, a little cluster of neurons in the so-called medial preoptic area, act as a thermostat and say, "Ah, the external of my body is cold and therefore I'm going to heat up my core body temperature.

" So it's a little bit paradoxical.

 People think, oh, if you getinto cold water or an ice bath, your body temperature is going to drop.

 And indeed, that's true ifyou stay in for a while, but if you just get in forabout one to three minutes, or under the cold showerfor one to three minutes, your core body temperature will increase.

 So then when you getout of that cold water, your body temperature isincreasing at a rate, at a slope, that's steeper than it would otherwise and you're going to feel more alert.

 It also has the advantage of increasing not just adrenaline, but dopamine, which is a molecule involved in motivation, focus, et cetera.

 So this is great for waking up.

 So we've got sunlight, we've got temperaturetriggered by cold water, and we have exercise.

 One of the best ways to increase your core bodytemperature early in the day is to do exercise.

 Now, some of you might choose to do your full-blown workout for the day first thing when youwake up in the morning, I would say the best time to exercise, at least what the research points to, is immediately when youwake up in the morning or three hours after wakingor 11 hours after waking.

 But that's really gettingdown into optimization for sake of muscularstrength and grip strength and it's very hard to givea strict prescriptive.

 Here's what I suggest.

 If you want to be alert early in the day and you want to sleep great at night, get that bright sunlight,get into some cold water, and if you don't want toget into some cold water, try and get some movement.

 It could be a walk.

 So you can get your sunlight exposure while you're taking a walkfirst thing in the morning.

 It could be a light jog.

 It could be skipping rope.

 These days, I skip rope forabout 10 minutes or 20 minutes while looking at the sun.

 So I'm trying to layerin these different things for waking up.

 And then I take a cold shower afterwards.

 This is what I've been doing as of lately, but I don't do that allyear long necessarily.

 Or some of you are going tobe working out mid-morning.

 I sometimes do that.

 But try and get your corebody temperature increased first thing in the morning, and a great way to do thatis with the cold water and/or with exercise.

 And again, it doesn't haveto be your full-blown workout for the day if you're doing workouts consistently, which I hope everybody is because everybody really should exercise at least, I believe, five or six, or maybe even seven days a week.

 For me, it's six daysa week, sometimes five, rarely is it seven.

 So get that exercise or even just a modest amount of movement, walking, jogging, skipping rope, some light calisthenics.

 That will further increaseyour core body temperature and help you feel more awake.

 Then we have the category of caffeine.

 And again, we're just talking about this early part of the day, and you might be saying, "Wait a second, I thought this was an episodeabout tools for sleep.

" Well, everything thatwe're talking about doing in these first 60 to 90 minutes of the day really set in motion awave of biological cascades that carry through the entire day and into the evening and into the night and really do serve to optimize sleep.

 So just hang in there with me.

 And for those of you that are interested in focus and attention,your ability to learn, all of these tools and practices are going to greatlyenhance those as well.

 So the next category of tool for use early in the day is caffeine.

 Caffeine is a very importantcompound to think about.

 I do realize that some peoplewho are prone to anxiety, especially panic attacks, anxiety attacks, might avoid caffeine entirely.

 That's absolutely fine.

 You do not have to drink caffeine.

 So what I'm about to describe are ways to leverage caffeine use to optimize sleep and wakefulness if you are comfortable withcaffeine, if you like caffeine, I happen to love caffeine.

 I like it in the formof coffee or espresso or yerba mate tea, in particular non-smokedvarieties of yerba mate tea.

 Non-smoked because the smokedvarieties seem to carry some carcinogenics, somecancer causing risk.

 There's increasing data on that.

 So non-smoked varieties of yerba mate.

 So caffeine is something that a lot of peopleconsume early in the day.

 How much depends on your tolerance, and there's a lot ofindividual variability here.

 Again, caffeine is anadenosine antagonist, or effectively works asan adenosine antagonist and limits sleepiness.

 I highly recommend that everybody delay their caffeine intake for 90 to 120 minutes after waking.

 However painful it maybe to eventually arrive at that 90 to 120 minutes after waking, you want, and I encourage you, to clear out whatever residual adenosine is circulating in your system in that first 90 to120 minutes of the day.

 Get that sunlight exposure, get some movement to wake up, and then, and only then,start to ingest caffeine because what you'll do ifyou delay caffeine intake until 90 to 120 minutes after waking is you will avoid theso-called afternoon crash.

 And you may still get alittle bit of dip in energy in the afternoon, but it's not going tobe that massive crash.

 I've talked about thereasons for that crash on previous episodes.

 But if you delay your caffeine intake 90 to 120 minutes after waking, you are doing yourself a greatservice towards wakefulness and to avoid the crash.

 And the afternoon crash hasanother liability to it, which is typically people will emerge from that afternoon crasheither grumpy or groggy and then they'll lean intodrinking more caffeine, which can then disrupt their sleep.

 So wait 90 to 120 minutesafter waking in the morning to drink caffeine.

 And if you drink caffeine atany point throughout the day, really try and avoid any caffeine, certainly avoid drinking more than a hundred milligramsof caffeine after 4:00 p.

m.

 and probably even better tolimit your last caffeine intake to 3:00 p.

m.

 or even 2:00 p.

m.

 And for many people,shifting that caffeine intake from immediately afterwaking in the morning to 90 to 120 minutes gives them a much longer arcof energy throughout the day and they don't feel the need to drink more caffeinelater in the afternoon.

 If you do drink caffeinelater in the afternoon, really try and limit thetotal amount or drink decaf.

 Certainly keep the total amount to less than a hundred milligrams if you are interested in getting into the best possible sleep.

 And I say this knowing thatmany people, including myself, can drink a double espresso with 200 milligrams of caffeine or more at 5:00 p.

m.

 or even6:00 p.

m.

 or after dinner and still, quote,unquote, fall asleep fine or still sleep fine.

 However, there are terrific data, Matt Walker and I talked about this, and there are more andmore papers all the time that point to the fact thatcaffeine intake late in the day, after 4:00 p.

m.

 that is, can really disrupt thearchitecture of your sleep.

 So you might think you're sleeping well, but you're not sleepingnearly as well as you could if you avoided caffeinein those afternoon hours.

 Now, some of you might be doingyour main about of exercise first thing in the morning and you want your caffeinebefore that about of exercise.

 In that case, I say, go for it.

 Drink your caffeine, do your workout right after waking up.

 I don't have a problem with that.

 You will find, however, that you're going to get anearly afternoon dip in energy and that dip in energy isgoing to be substantial because it's going to be a dip in energy that naturally follows thatworkout from the morning.

 So it's dependent on temperature, and it's going to be related to the elimination of thatadenosine blockade by caffeine.

 So you're getting akind of a one-two punch on your energy levels by taking a lot of caffeine andexercising early in the day.

 You can sort of expect that you're going to get a drop in energy in the early afternoon.

 That's okay if that works for you, but just know that delaying that caffeine 90 to 120 minutes after waking would be the ideal scenariomost days and most scenarios.

 All that said, Iabsolutely respect the fact that people have different work schedules, kid schedules, et cetera.

 So if you want to do someor none or all these tools, that's really up to you.

 I'm just providing them to you in the simplest form that Ican possibly provide them.

 Now, the other lever or tool that you have available to you is food.

 Not just what you eat, but when you eat.

 And it turns out that ifyou eat early in the day, you support a biological clock mechanism that will make you morealert early in the day.

 That said, many people choose to fast in the early morning hours of the day or in the first part of the day.

 I'm one such person.

 I generally don't ingest any food until about 11:00 a.

m.

 or 12 noon.

 Sometimes I'll have a protein shake.

 Sometimes I'll have some almonds.

 Sometimes I'll have breakfast.

 If people are meetingfor brunch or breakfast, I will have breakfast for social reasons every once in a while.

 But most of the time I don'teat until about lunch time.

 However, some people are really hungry when they wake up in the morning.

 Just know that if youeat early in the day, you are further triggeringan increase in metabolism and in temperature thatwill make you more alert.

 So you don't have to eat early in the day, but you can start to see how these different tools layer together.

 Sunlight viewing, exercise,cold water, eating.

 Many of them are convergingon the same mechanisms.

 In fact, when you drink caffeine, there's also a smallincrease in body temperature due to the adrenalineincrease that it stimulates.

 So all of these things can belayered on top of one another or you can use them individually or think about them individually.

 Now, food is an interesting lever or tool because it's not just about when you eat, but it's also about what you eat.

 And I've talked a lotabout eating for energy and what that means interms of caloric energy versus neural energy, et cetera, in previous podcast episodes.

 We're not going to focus on that now because, frankly, toget into a description of whether or not somebodyshould eat fruits or vegetables or animal proteins or dairy,et cetera, early in the day, that's very nuanced.

 What you eat for your breakfast, or if you choose to not eat breakfast, is really up to you.

 All that said, if youeat a very large meal, it doesn't matter if youslept terrifically well 10 hours the night before or if you are about to go to sleep or if it's the middle of the afternoon, if your gut is full of food, there's just a largevolume of food in your gut, it's going to divert a lot of blood and other critical resources away from other organs of your body, in particular, your brain, and you're going to be sleepyafter eating a big meal.

 So this is sort of a duh, but I think oftentimes in the discussions about what to eat for energy, people neglect to consider food volume as a strong parameter orvariable in that discussion.

 So if you eat a huge breakfast, it's likely that you are going to be tired immediately after eating that breakfast unless of course you exercisevery hard prior to that and you metabolize allthat food very quickly.

 So it's up to you whether or not to eat first thing in the morning or not.

 But if you do eat in the firstfew hours of the morning, just understand that you are setting or you are helping to set a food entrained, as it'scalled, circadian clock.

 Light, temperature, timing of food intake, movement and exercise, all of these things literallyfunnel in in a neural sense, they funnel into this thingthat we call the circadian clock and they let that clock,that set of neurons, predict when you are likelyto be eating and active and viewing sunlight the next day and the nextday and the next day.

 I say all this because thereare some beautiful studies, and I'll highlight one, again,in the show note captions, that show that if peopleare having a hard time waking up in the morning, one of the things they can do is maximize sunlight viewing,exercise in the morning, drink caffeine.

 Although, again, I support the idea that that would best be done about 90 to 120 minutes after waking.

 Eating some food in thoseearly morning hours, et cetera, et cetera.

 You can layer in multiple levers or tools in order to be more alert.

 And that's what these leversand tools are really there for in this sense of whatwe're talking about today, which is optimizing sleep.

 Yes, they will make you more alert.

 Yes, they will provide someadrenaline and dopamine, for instance, the coldwater, et cetera, et cetera.

 But the reason we'retalking about these things in the context of sleep is that they start to give your body some predictable autonomic timing.

 What is predictable autonomic timing? Well, your autonomic nervous system is the components of your brain and body that cause wakefulness and sleepiness and you can start tocreate some predictability in that autonomic timing.

 You can start to do thingsthat really make it such that you naturally wakeup at six in the morning or five in the morning.

 That's right, if you're somebody who naturally is a night owl, who likes to stay upuntil two in the morning and sleep until 10:00 a.

m.

, and you now have a job oryou have to go to school or you have a partnerthat likes to get up early and go to sleep early, well, you can make that happen and you can make thathappen pretty painlessly if you take a week or so and go to sleep 30 minutes oran hour earlier each night, set an alarm and wake up 30 minutes oran hour earlier each morning until, of course, you're waking up at the time you want to wake up, and then even in that groggy state, get some exercise, getsome sunlight viewing.

 If the sun's not out, turn on those bright artificial lights.

 Have some breakfast, evenif you're not hungry.

 In fact, for those of youthat engage in shift work because you have to, or travel and you're jet lagged, one of the quickest ways toshift your circadian clock and get onto the local schedule is to eat on the local schedule.

 So what all these tools do isthey really set up a cascade.

 Think of it as kind of awavefront of wakefulness and focus throughout the day.

 It'll take you throughthe middle of the day and the afternoon stage we'lltalk about in a few minutes, but really they take you to this period that is about 5:00 p.

m.

until your bedtime.

 I realize some people aregoing to bed very early, like 8:00 p.

m.

 or 9:00 p.

m.

,which to me seems very early, but very few people go tosleep at 5:00 p.

m.

 right? Unless you're doing that forshift work or other reasons.

 But from 5:00 p.

m.

 until bedtimeis really a critical period in which you need toleverage particular tools in order to get and stay asleep optimally and to be able to sleep through the night.

 So really there are three critical periods throughout each 24-hour cycle.

 And during each of those critical periods, you're going to want to do as many specific things as you can to optimize your wakefulness and focus and mood throughout the day and your sleep at night.

 The first critical period is the one that we've beentalking about up until now.

 Things like morning sunlight viewing, caffeine 90 to 120 minutes after waking, exercise, and so on.

 We can call that critical period one and it really encompasses thetime from which you wake up until about three hours after waking.

 Although, I should just mention 'cause there are alwaysthose people that say, "Wait, I wake up at 4:00 a.

m.

 and the sun isn't out until 8:00 a.

m.

," okay, so it might be four hours.

 But really it's those earlymorning hours of your day once you're awake.

 The second critical period is the time throughoutthe day and afternoon leading into evening.

 So you may ask what arethe things that you can do throughout the day, the middle of your day and into the afternoon and evening hours, that are really going to set you up for the best possiblesleep later that night.

 Well, there are a few dosand there are a few don'ts.

 First of all, be careful about ingestingtoo much caffeine throughout the middle of the day.

 That's kind of an obvious one for the reasons that wetalked about earlier.

 Second of all, if you are a napper, and I raise my hand now, for those of you listening, I'm raising my righthand because I love naps.

 I've always loved naps.

 Nowadays I do NSDR ora Reveri sleep hypnosis almost every day.

 And I tend to do that, as I mentioned, in the early afternoon hours if I'm feeling kind of sleepy, because even though I optimize my caffeine intake timing, et cetera, I tend to get a littlesleepy in the afternoon.

 Most people get a littlesleepy in the afternoon.

 Some of that is related to hitting that peak of body temperature.

 And you might think, wait, Ithought high body temperature is associated with alertness, and it is, but right as you crestthat high body temperature and your body temperature starts to drop, there's a tendency tobe a little bit sleepy.

 So some of you might opt totake a nap in the afternoon.

 Should you nap, should you not nap? That's a question that I get asked a lot and that I asked Dr.

 Matthew Walker when he was a guest on this podcast.

 Here was his answer andhere's what the data support.

 It is fine to nap in the afternoon, but don't nap so late inthe day or for so long that it disrupts your ability to fall and stay asleep at night for your major sleep about, okay? So naps are fine, but don't sleep so long during the day or too late in the day that it disrupts your abilityto fall and stay asleep.

 I should also say you do not have to nap.

 It's kind of an interesting phenomenon that happens on thesepodcasts and on social media where we'll talk about naps and the fact that naps are great, but don't make themlonger than 90 minutes, but then all the non-nappersget really worried.

 Like, wait, am I supposed to nap? I don't like naps.

 I wake up groggy.

 You do not have to nap.

 In fact, if you can make it through your whole day without napping, great, more power to you.

 But if you do nap and youfind that naps serve you well, keep those naps shorter than 90 minutes for reasons related toultradian cycles and so forth, and make sure that you don'tnap too late in the day that you are then stayingup too late at night and having a hard timewaking up the next morning.

 I will say that for a lot ofpeople who do not like naps or that find they wake upreally grumpy from naps or groggy from naps, I encourage you to try the Reveri app, try an NSDR script, try yoga nidra.

 Try something of that sort for anywhere from 10 to 20 to 30 minutes.

 I tend to do this every day now.

 I'll just lie down, and I love yoga nidra, I love NSDR scripts, I love using the Reveri app.

 In particular, theportion of the Reveri app that gets you better at sleeping.

 It really is beneficial for me because it serves as very replenishing while I'm doing that hypnosis, but it's also gotten me much better at falling and staying asleep and falling back asleep inthe middle of the night.

 So this critical period throughout the day is one in which most peopleare doing a lot of stuff.

 They're emailing and picking up kids and they're exercisingand they're commuting and doing all sorts of things, taking phone calls and Zooms, et cetera.

 But if you can get thatperiod of deep relaxation through a nap or NSDR, that's going to serve you well.

 Try not to drink too much caffeine, certainly no more than ahundred milligrams of caffeine, after 4:00 p.

m if your goal is to fall asleepat a reasonably normal time.

 And for those of you thatexercise in the afternoon, understand that if youexercise very intensely, so this might be weighttraining or running or some other very intense exercise, typically that's going to further increase your body temperature.

 Makes sense, right? Based on everything we know about metabolism and body temperature.

 And it's going to so-calleddelay your circadian clock.

 It's going to make it such that you want to fallasleep a little bit later, maybe even a lot later.

 So if you're exercising inthe afternoon or evening and that's the only time you can exercise or that's the time thatyou prefer to exercise, great, but be careful aboutingesting too much caffeine in order to get theenergy to do that exercise 'cause that caffeinewill disrupt your sleep and just know that you aredelaying your circadian clock.

 You are making it such that you will naturallywant to go to sleep later and wake up later.

 Contrast that with if youexercise early in the day, say, immediately after waking up or in the first zero tofour hours after waking, in most cases, that's not going to shift your circadian clock much.

 And toward the end of the episode, we'll talk a little bitabout forced exercise prior to wake-up times.

 That doesn't mean doingexercise in your sleep.

 That means deliberately setting an alarm and getting out of bed much earlier than you naturally would.

 That turns out to be a very potent tool to so-called advance your circadian clock.

 So we can talk about that alittle bit later in the episode.

 But this critical period,too, in the middle of the day is when you're going to wantto leverage specific tools, and we've talked about those: limiting caffeine intake; being mindful of theclock-delaying effects of exercise; the fact that, also,if you're going to nap, you don't want to nap toolong or too late into the day otherwise you'll disruptyour nighttime sleep.

 So this critical period two, or second critical period, I should say, during the middle of the day is a time in which you shouldbe doing certain things and avoiding doing certain things.

 So that raises thequestion of whether or not you should also be getting a lot of light, in particular, sunlight,throughout the day.

 Now, that's something thathasn't been explored too much in the literature until recently when Dr.

 Samer Hattar who's the director ofthe chronobiology unit at the National Institutesof Mental Health, decided to do a number of experiments exploring the effects of light on mood and other aspects of brainfunction and body function when that light is deliverednot just in the morning, which is great for us, but also throughout the day.

 So should you be looking at sunlight or bright artificiallights throughout the day? Now, on the face of it, you might just think, yes,you know, sunlight's great.

 Provided we're not getting a sunburn and we're not staring at thesun and damaging our eyes, we should get as muchsunlight as we possibly can.

 In fact, we talked about thisin the episode on hormones about how getting lightonto as much of our skin as we can throughout the day can really help in the production of testosterone and estrogenin both men and women in healthy ways thatimproves mood and libido and all sorts of things thatare associated with wellbeing.

 However, because light issuch a powerful stimulus for controlling the timing of your sleepfulness, orsleepiness, I should say, and wakefulness, we might want to be cautious about how much light we areviewing in the afternoon, in particular, in theearly evening hours, right? Well, turns out it'snot so straightforward.

 Viewing, so sunlight to the eyes, sunlight in the late afternoon and evening hours, so again, depends on time of year, depends on location thatyou happen to be in, but getting some sunlight in your eyes for, again, maybe fiveor 10, maybe 30 minutes, depending on how muchcloud cover there is, doing that in the afternoon serves an additional beneficial purpose, which is you protect or youinoculate your nervous system against some of the negative effects of bright artificial light or even dim artificiallight in the nighttime hours between 10:00 p.

m.

 and 4:00 a.

m.

, which is really critical period three.

 And we'll talk about whatto do and what to not do during critical period threeof every 24-hour cycle.

 But to make it very clearwhat I'm saying here, get that morning sunlight in your eyes, but also get some sunlight in your eyes in the late afternoon and evening hours when the sun is atso-called low solar angle, when it starts to descend in the sky.

 Again, you don't have tostare directly at the sun, although if you can catcha nice, beautiful sunset, go for it.

 But as the sun starts to descend, it triggers those same neurons in your eye that communicate withyour circadian clock, but it communicates witha different component or different compartmentwithin the circadian clock.

 That circadian clockis not just one thing.

 It's multiple things.

 And you have what arecalled morning oscillators and evening oscillators.

 And to make a long story short, the tool that I'm describingof looking at the sun in the late afternoon and evening, again, blinking is fine, don't stare at the sun, but getting that sunlight in your eyes in the late afternoon and evening signals to that clockthat it's evening time and that sleep is coming.

 It also serves as a secondanchor or reference point for your body and your brainto know where it is in time.

 Remember back to thebeginning of the episode when I said your brain andyour body and all your organs are locked inside this skin and this skull and they don't know what'sgoing on in the outside world.

 Well, that morning sunlight viewing and the other things you doduring critical period one, those provide one strong set of signals that it's wake-up timeand time to be alert and time to be focused.

 And then in the evening, by getting sunlight in your eyes again, in particular, sunlight that comes from low solar angle sunlight, well, that provides a second stimulus or a second reference point that tells your brain andbody, "Hey, it's evening.

 The sun is descending.

" Now, you might say, "Wait, how does the brainand these neurons know the difference between morninglight and evening light?" It turns out has to do with the particular wavelengths of light that are present inmorning versus evening.

 It's an incredible mechanism.

 And you are probablyfamiliar with the fact that when the sun is directly overhead, it's really bright white and yellow and the sky's often blue, and if there's cloud cover, it just comes through asa bunch of bright light, well, next time you're out in the morning, take a look at what a sunrise looks like.

 There's a lot of yellow-blue contrast, and those yellow blues signal important specific sets ofcells in your eye and brain that it's morning.

 In the evening, you're alsogoing to see yellow and blue, but the ratio of yellowsand blues has now changed and you also see some oranges, and in a really brilliantsunset, you'll see some reds.

 If you haven't noticed this already, you'll really want to look for this.

 It's really kind of funand cool to look at.

 Well, those yellows and blues and oranges that you see in the evening sunsets, those signal to your brainand body that evening is there and that nighttime is coming and they're really establishing a second reference point orwavefront of biological signals that are going to optimizeyour nighttime hours and your transition intoreally terrific sleep.

 So now let's talk about what I'm callingcritical period three of each 24-hour cycle.

 So this would be the periodof time of late evening, So it might be 6:00 p.

m.

 for some, depending on when you go to sleep, or 7:00 p.

m.

 extending into the hours in which you decide to getinto bed and go to sleep and then throughout the night.

 There are a number of things that you're going to want to do and there are a number of things that you are going to want to avoid doing in order to optimize your sleep.

 First of all, you'regoing to want to avoid bright artificial lights of any color.

 Yes, of any color.

 We haven't talked a lotabout blue blockers, you know, lenses thatblock blue wavelengths or short wavelengths of light.

 I don't have anythingagainst blue blockers.

 In fact, many people find thatblue blockers provide them some relief from headacheand some eye strain if they wear blue blockers throughout the day and certainly at night.

 But you don't need them, and even if you do wear them, you will find that iflights are very bright, doesn't matter if it's a blue light, a yellow light, or a red light, those bright lights willwake up your brain and body.

 They will activate the same mechanisms that were activated earlyin the day by sunlight.

 However, and here's thereally diabolical twist, I mentioned this earlier, but the diabolical twist in the way that your brainand body respond to light is that early in the day, in the morning hours, youneed a lot of bright light, ideally from sunlight, to be very alert and to wake up, but in the evening hoursand nighttime hours, it takes very littlelight, very few photons, in order to wake up your brain and body and to disrupt your circadianclock and disrupt your sleep.

 So what that means is thatonce the sun goes down, which, of course, is going to happen at different times of yearin different places on earth, but once the sun goes down, you would be wise totry and dim the lights in your indoor environmentmost days, right? I realize some nights you'regoing to throw a party and have people over.

 You might not want to dim the lights.

 Some nights you're going to go out, you might view a lot of bright lights.

 But most nights of your life, you're going to want to dim the lights in your internal environment.

 And ideally, the lights that you do use you would place low inthat physical environment.

 So you would try andnot use overhead lights, but rather rely on desk lamps or lights even placed low to thefloor, even on the floor.

 If you are going to use light at night, and most people do, I would encourage you to useas little artificial light as is required to carryout the activities you need to require safely.

 That could be studying, in which case you mightneed a little bit more light in order to read or study.

 If you're watching a television show or you're watchingsomething on your computer, dim that screen way, way down, as dim as possible whilestill, of course, being able to view what you need to view.

 Even better, I should say, ideally, you would use candlelightand/or moonlight.

 Now, some nights the moon is really bright and you actually can use moonlight to go about your usual activities.

 Moonlight might seem very, very bright, but, actually, moonlight isfairly low light intensity, and candlelight, whichcan also seem very bright, actually is very low light intensity.

 If you're sitting across a table with some candlelight there and it's a really bright candle, chances are it's onlyabout three to 10 lux, which is very, very little light energy compared to, say, an artificial desk lamp or an overhead light, which is going to be in the area of anywhere from ahundred to a thousand lux.

 So candlelight is fine.

 Of course, be cautious with open flame, but candlelight is fine.

 Moonlight is fine.

 Dimming artificial lights is fine provided they're dimmed way, way down.

 And again, try and avoid usingoverhead artificial lights.

 The absolute worst lights are going to be overheadfluorescent lights of the sort that you wouldhave in the supermarket or that you would see at a gas station or something of that sort.

 And I confess, there are timesin which I'm driving home and it's late at night and Iwant to be able to get to sleep and I'll need to stop at the grocery store or a gas station or something like that, I've actually put on sunglasses at night in order to avoid getting that bright light exposure at night.

 Although that's a little bit extreme, I have done that from time to time because that bright light exposure will absolutely quash, it will eliminate, any melatonin thathappens to be circulating in your brain and body.

 Now, melatonin, a lot of peoplethink of it as a supplement, but melatonin is naturally released as the evening comes aboutand into the nighttime hours.

 It's the hormone thatmakes you feel sleepy and allows you to fall asleep.

 So viewing bright light in the late eveninghours and nighttime hours is really not good for your sleep quality and your ability to fall and stay asleep.

 So for most people, a simple rule of thumb is going to be avoid brightartificial lights of all colors, and in particular, overheadbright artificial lights, between the hours of10:00 p.

m.

 and 4:00 a.

m.

 That's right, between10:00 p.

m.

 and 4:00 a.

m.

, avoid those bright artificiallights as much as possible.

 Use only as much light asis absolutely necessary in order to carry out theroutines and activities you need to carry out safely.

 I should mention that the reason overheadlights are problematic is the same reason whysunlight is so great early in the day, which is that the cells,that is, the neurons, that can wake up your brain and body through activation of the circadian clock reside mainly in the bottom half or 2/3 of your neural retina and the way the optics of your eyes work is that the cells on thebottom half of your eye view the upper visual field.

 So this is a beautiful adaptive mechanism that allows these cells to respond to overhead light from sunlight in the early part of theday and throughout the day.

 But in the evening, if you havebright artificial lights on and those bright artificiallights are overhead lights, it's going to more closely mimic what sunlight does in the evening time, and that turns out to be a bad thing if your goal is to eventually go to sleep.

 So again, do like the Scandinavians do.

 Use lights that are setlow in the room at night, and if you really want tooptimize your sleep-wake cycles, I suppose you could also do theopposite throughout the day.

 You could really emphasize the use of bright artificial lights and sunlight that comes from above.

 And of course, sunlightalways comes from above.

 But if you're working ina given office environment and, you know, it's 2:00 p.

m.

 or 3:00 p.

m.

 and you want to be as awake as possible, really crank up the overhead lights.

 And then in the evening, which is this critical periodthree that we're referring to, really try and dim thoselights or have them off or just rely on candlelight or moonlight from the hours of about10:00 p.

m.

 until 4:00 a.

m.

 Our good friend Samer Hattar, who's been on this podcast before, Samer is director ofthe chronobiology unit at the National Institutesof Mental Health, well, he's absolutely obsessiveabout this light stuff and avoiding light at night.

 In fact, he lives in what I sort of joke is like a cave at night.

 From 9:00 p.

m.

 until 5:00 a.

m.

, which is really his kind of sleep cycle, he has his house so dark that you'd be lucky to be able to find a spoon in the kitchen.

 In fact, you'd be lucky to find your way downthe hallway if you're me.

 But in any case, dim the lights.

 Turn them way, way down.

 It will serve you well.

 It will make it much easier for you to get sleepy and staysleepy and fall asleep and stay asleep throughout the night.

 Now, not to depart fromthis critical period three, but if you recall, viewingthat afternoon light, the low solar angle light as the sun is heading down in the sky, so it could be sunset or what I call circasunset, around sunset, well, doing that is going to slightly, but not completely, offsetany of the negative effects of viewing artificial light at night.

 So I don't want to givepeople a pass here, but let's say you know that you're going to watchsome Netflix at night or you're going to be up late studying and yet you still want to beable to fall and stay asleep.

 Definitely make sure yousee that evening light.

 There's a great study.

 We'll provide a link to this study, which showed that if peopleview evening sunset light or evening sunsets or sunlight right aroundthe time of sunset, it really serves toinoculate or offset some, again, some, not all,of the negative effects of artificial light between the hours of10:00 p.

m.

 and 4:00 a.

m.

 Now, that's light.

 But as you recall, we also have this toolrelated to temperature, and you're probably notgoing to be surprised that the way to leveragetemperature in the evening is the exact opposite of the way that you wantto leverage temperature early in the day.

 Early in the day, temperature increases from cold showers or exercise,et cetera, wake you up.

 What that means is that takinga cold shower late at night is probably a bad idea.

 Rather, taking a nice hot bath or a sauna, you might think would heat up your body, and indeed, that's what happens if you stay in a very long time, but if you do hot tub or a hot bath or a sauna in the evening, and you don't stay in formore than 20 or 30 minutes and you get out, you take maybe a cool-ishshower or a warm shower, then what happens is there'sa compensatory cooling off of your core body temperature for the reasons we discussed earlier, and your body temperature willdrop by one to three degrees and it will make it mucheasier to get into sleep.

 So if you're somebody that enjoys hot baths,hot showers, or hot tubs, evening and nighttime is going to be the best time to do that if your goal is to facilitate sleep.

 Similarly, you should try and make your sleeping environmentpretty cool, if not cold.

 Now, that doesn't mean you need to be cold while you're asleep.

 You can get under as manyblankets as you need, but it's a good idea to makeyour sleeping environment cool.

 In fact, drop the temperaturein that sleeping environment by at least three degrees and you'll be happy that you did.

 Now, some people rely onthings like Eight Sleep.

 I use that.

 One of these controllabletemperature mattress covers.

 Other people would simply do this by putting a fan in theroom or opening a window.

 Again, depends on time of year, depends on technology,depends on budgets, et cetera.

 But you're going to want to sleep in a relatively cool orcold sleeping environment and then layer on the blanketsas needed to stay asleep.

 And I say as neededbecause one of the things that you're going to do in your sleep, or if you happen to wake up, is if you're too warm, you'regoing to put a foot or a hand out from under those blankets.

 And the reason for doingthat is very logical once you understand the mechanism.

 You have special portals, you essentially have ways of passing heat, excuse me, in and out of your body primarily through the palms of your hands, the upper half of your face, and the bottoms of your feet through so-called glabrous skin.

 This was covered in theepisode with Dr.

 Craig Heller from the biology department at Stanford.

 If you lower the temperaturein your sleeping environment, so lower the temperature in that room or use a controllable mattresscover that can cool down like Eight Sleep orsomething of that sort, it's naturally going to makeyour sleep environment cooler, and if you're too warm under the blankets, all you have to do isextend a hand or a foot out from under those blankets.

 Whereas if the sleepingenvironment that you're in is too warm, there's very little you can do to cool off besides push off those blankets.

 So for instance, if you're too warm and you're waking up inthe middle of the night, which is what happens if you get too warm, you'll push off those blankets.

 But if the room is too warm, well, what are you going to do? You'd probably have to putyour hands into some cool water or take a coolish shower or something for a couple of seconds.

 That's not very practical.

 Better to just keep thesleeping environment cool.

 I'm not a big fan ofpeople putting socks on while they sleep, or I should say, I'm nota fan of putting socks on while I sleep, because that eliminatesthis glabrous skin portal on the bottoms of one's feet.

 So for those of you that have heard, you know, wear socks while you sleep, that works great for people that tend to run too cold while they sleep and wake up because their feet get cold, but if you're somebody who wakes up in the middle of the night, chances are you're waking up because you're getting too warm and the best thing that you could do is to cool or lower the temperature in the room that you're sleeping and not wear socks, get under as many blanketsas you need to fall asleep, and then across the night, you'll naturally justmove a hand or a foot or all hands and feet outfrom under those blankets to cool off because of the relationshipbetween temperature and sleep.

 That is, dropping yourcore body temperature one to three degrees gets you into sleep andhelps you stay asleep.

 So let's say you doexercise late in the day and you're finding yourselfvery alert in the evening and you need to fall asleep, or let's say you've exercised and you needed four cups of espresso in order to do that exercise.

 Well, there are a fewthings that you can do to try and bring your nervous system down into more state of calmness, and you can do that also by lowering yourcore body temperature.

 One of those I alreadytalked about before, taking a nice hot shower or a hot bath and then getting out and cooling off will decrease your body temperature.

 Maybe not enough to get you into sleep if you have a ton ofcaffeine in your system.

 But again, you can use thismechanism of temperature shifts to wake up or temperature shifts to fall asleep in ways that really can help you overcome some of the irregularitiesin your sleep-wake cycle and exercise cycle, et cetera.

 Because, of course, nobody's perfect.

 Some days we end up havingto workout in the afternoon or we'll miss the workout entirely.

 Other days, we end uphaving that cup of coffee in the afternoon with a friend and then we have a hardtime falling asleep.

 So you can use these tools not just in their optimized form, you know, being absolutelyobsessive and compulsive about exactly when youdo each of those tools.

 That would be wonderful,but life happens as they say and some days you're goingto feel too alert at night and you want to fall asleep, or you've got to get upespecially early the next morning and you're not somebody who normally goes to bed at 10:00 p.

m.

 Well, that's when a somethinglike a hot bath or a sauna can really benefit you because it can adjust yourtemperature rhythm accordingly.

 I would be remiss if Ididn't touch on alcohol and CBD and THC.

 I always get questions about these.

 And I should say, of course, many places, but not all, THC is illegal.

 Although, there are medical uses and in some places, it's decriminalized, other places it's legal.

 Alcohol, of course, is consumed almost as frequently ascaffeine is consumed.

 I personally don't drink alcohol.

 I don't have anything against it per se.

 I just don't tend to enjoy it.

 One of the reasons I don't enjoy it is if I drink alcohol,I simply fall asleep.

 So that doesn't really accomplish any of the things that Ireally want to accomplish because the sleep that onegets after drinking alcohol is greatly disrupted sleep.

 Hate to break it to you,but that's the truth.

 And when Dr.

 Matt Walkercame on this podcast, he said exactly the same thing.

 While THC and alcohol dohelp some people fall asleep and maybe even stay asleep, the architecture ofthat sleep is suboptimal compared to the sleep they would get without alcohol or THC in their system.

 So I'm not here to tell youwhat to do or not to do.

 I'm certainly not the substance police.

 That's not my role.

 I'm just reporting to you the biology.

 If your sleep is not restoring you to the extent that you feel it should, or if you are regularlyrelying on a drink or two in order to fall asleep, or THC in order to fall asleep, that is disrupting yourtotal pattern of sleep.

 However, I do realize that nowadays a lot of peopleare relying on THC and/or CBD, especially edible forms, in order to fall and stay asleep.

 And, you know, we canjust acknowledge the data.

 It does seem that there'san anxiety lowering effect of some of those compounds that do help people who have a hard timefalling and staying asleep because of reasons related to anxiety.

 Although, in a moment, we'll talk about some supplementsand supplement protocols that can also assist in theability to fall and stay asleep and that can adjust anxiety and that do not seem todisrupt sleep architecture in negative ways and, in fact, can enhancethe depth and quality of sleep architecture.

 Okay, so you've done everythingcorrectly up until now.

 You got your morning routinefrom critical period one.

 You've got your afternoon routine.

 You saw some sunlight in the afternoon.

 You avoided caffeine in the eight hours or 10 hours before bedtime.

 You're not drinking alcohol.

 You've cooled down the room.

 You're doing all these things right.

 You've dimmed the lights,et cetera, et cetera.

 What else can we do inorder to optimize our sleep? Well, I always say behavioral tools first, then look to nutrition, then, if necessary,look to supplementation, and then, if still necessary,look to prescription drugs obviously prescribed by aboard certified physician.

 Well, we've talked a lotabout the behavioral tools for critical period three.

 We have not talked a lot about the supplementation-based tools.

 There are supplements that for most people will greatly improve theirability to fall and stay asleep and the three mainsupplements in that category or that kit of sleep supplements, and I've talked about these before, are magnesium threonate,so T-H-R-E-O-N-A-T-E, apigenin, A-P-I-G-E-N-I-N, apigenin, and theanine, T-H-E-A-N-I-N-E, theanine.

 Now, some important things to point out about mag threonate, as it'scalled, apigenin, and theanine.

 First of all, you don't necessarilyneed to take all three, although, many peopleget a synergistic effect from taking all three.

 In fact, you may not evenneed to take even one.

 What I recommend is thatif you're already doing all the behavioral tools regularly and you're still havingtrouble falling asleep and staying asleep, well, then you might tryone of the supplements within this sleep stack.

 They do have fairlywide margins for safety.

 Although, I should also say, anytime you're going toadd or remove something from your supplement protocolor your nutritional program, you definitely want totalk to your physician.

 I don't just say that to protect us.

 I say that to protect you.

 But for most people, the marginsof safety on these things are going to be pretty broad.

 A couple of notes about dosages.

 For some people, the dosagesof any one or several of the supplements Imentioned will be zero.

 That is, you won't need them in order to get and stay asleepmost nights of your life.

 That's terrific if you don't need them.

 For many people, however, taking 145 milligramsof magnesium threonate can be very beneficial.

 That's the dosage that mostpeople will benefit from.

 Some people need to go a little higher.

 Some people need to go a little bit lower.

 One of the reasons thatwe've been pointing people towards single-ingredientformulations these days is because it allows people to adjust the dosage of one component of a so-called sleep stack without having to disrupt thedosage of another component, and so on.

 It also allows people to try just one element within the sleep stack without having to purchaseand try the others, which is a problem ifyou're buying a blend of a lot of different ingredients.

 So 145 milligrams of magnesium threonate.

 50, 5-0, milligrams of apigenin.

 And again, you could justtake the apigenin on its own.

 And 100 to 400 milligrams of theanine taken, again, alone or in combination with the other supplementsmentioned in the stack many people find allowsthem to get really drowsy and fall asleep, sleep really deeply, and they feel much morerefreshed the next day and they don't have a grogginess to them.

 Now, a couple of notes aboutthese different supplements.

 About 5% of people report that magnesium threonatereally disrupts their gut.

 It gives them diarrheaor gastric distress.

 In which case, don't take it.

 If magnesium threonate disruptsyour gut or your digestion to a point where it'suncomfortable or at all and you don't like it,don't take any of it.

 The proper dosage for you, in other words, would be zero milligrams.

 Now, in a slightly different way, many people who cantolerate magnesium threonate or really thrive on magnesium threonate and like apigenin might find that theanine, even at the lowest doseof a hundred milligrams, 'cause, again, the range isa hundred to 400 milligrams, that theanine gives them such vivid dreams that they actually find it disruptive where they wake up inthe middle of the night or they find that thesleep that they're getting is kind of anxiety ridden because of the intensity of those dreams.

 So some people mightchoose to leave theanine out of the sleep stack and just take magnesiumthreonate or apigenin And again, some people mightleave magnesium threonate out of the sleep stack.

 Again, all of this is really about finding the supplementation protocolthat's ideal for you.

 I should mention that whether or not you're taking one or twoor three of the components of the sleep stack, the ideal time to take those is 30 to 60 minutes before bedtime, especially if you haven'thad anything to eat for the three hours or so before bedtime.

 I confess that oftentimes I'll have a little bit of asnack late in the evening, some berries or something.

 I try not to eat too close to bedtime, but some evenings justbecause of work schedule, I'll get home late, be 9:00 p.

m.

, and I'll eat a big meal and then I'll take thesleep stack and fall asleep.

 Every once in a while,that just so happens.

 Nobody's perfect.

 Certainly I'm not.

 But that sleep stackcan be very beneficial.

 And I do think that it'spreferable to melatonin.

 Here's the reason.

 First of all, melatonin is a hormone that you endogenously make.

 You now know a lot about melatonin and it's controlled by light, meaning light inhibitsit or eliminates it, darkness promotes it.

 And melatonin indeedcan help us fall asleep, but the dosages of melatonin that are contained inmost commercial products is far, far, far greater than what we would make endogenously.

 So it's really supraphysiological.

 So that's of concern because melatonin is not just responsible for making us sleepy and fall asleep.

 It also does things like interacts with other hormone systems, testosterone and estrogen, even in the puberty system, in kids.

 Is taking melatonin everyonce in a while a problem for adjusting to jet lag, et cetera? Probably not.

 I would even say no.

 But taking it chronically over time, especially kids takingit chronically over time, can potentially be problematic.

 So at least in my opinion,these other supplements are going to be preferable to melatonin.

 Now, as I mentioned in thebeginning of today's episode, there are some other things that I certainly takeevery once in a while and that other peoplemight consider taking in addition to the sleepstack I talked about before or in place of that sleep stack if that sleep stackdoesn't work well for them.

 So every third or fourth night, I will take two grams of glycine and a hundred milligrams of GABA in addition to the standard sleep stack that I talked about before.

 So I'm taking mag threonate,apigenin, and theanine, and then I will also take twograms of glycine and GABA, which I find greatly enhancesmy ability to get into sleep.

 But the reason I only add glycine and GABA every third or fourth night is that if I take it too often, I find that the entire sleep stack doesn't work quite as effectively.

 I don't know exactly why this is the case, but in any event, that's what I do.

 And more recently, I'vealso started using inositol, in particular myo-inositol.

 Every other night, I'll take900 milligrams of myo-inositol in addition to mag threonate,apigenin, and theanine, and not on the nights whenI take glycine and GABA.

 So I'm adding 900 milligrams of inositol to the standard sleep stack of mag threonate, theanine, and apigenin.

 And what I find is not onlydoes it greatly enhance my ability to fall asleep quickly, but if I wake up in themiddle of the night, which I often do to use the bathroom, I find it very, veryeasy to fall back asleep.

 Whereas when I don't takeinositol every other night or so, I find that if I wake upin the middle of the night, it's a bit more of achallenge to fall back asleep.

 So inositol has a number of different uses that have been discussedin terms of mental health and in terms of adjustinganxiety for its daytime use.

 What I'm talking about is taking 900 milligrams of myo-inositol also 30 to 60 minutes before sleep along with the standard sleep stack and I found that to beimmensely beneficial.

 I also noticed that ithas a pretty long tail of anxiety suppression throughout the day.

 And I'm not somebody whosuffers from anxiety, but I have to say it just has led me to feel a bit calmer throughout the day, and I don't really know how to say this except in subjective terms, to feel a bit more buffered against or resilient against stress events.

 And if you look at theliterature on inositol and its interactions with the serotoninsystem and other systems, that all makes sense as towhy that would be the case.

 So we'll provide links toour so-called sleep kit, which is part of ourNeural Network Newsletter.

 It's a zero-cost newsletter where you can access thisinformation about supplements and other behavioral toolsfor sleep in list form.

 But that sleep kit doesn't include some of the newer information that I've provided this episode, in particular, theinformation about inositol and what I'm finding to be the very beneficial use of inositol for the ability to fall back asleep after waking up in themiddle of the night, which is something that alot of people struggle with.

 Now, that's supplementationfor falling and staying asleep, but we can return to the behavioral tools also as powerful levers and tools for falling asleep andgetting back to sleep.

 And again, we look toNSDR, non-sleep deep rest, or the Reveri app as a way to do that.

 As I mentioned earlier, the Reveri app has beendeveloped on the basis of really high-quality,peer-reviewed research, both clinical and non-clinical, by my colleague, David Spiegel, who's our associate chairof psychiatry at Stanford.

 It's a wonderful tool.

 It does carry a cost afterthe initial seven-day trial.

 I can tell you what the cost on that is so you can get a sense because I do realize thatanything that carries a cost, for some people, it won't be accessible.

 Right now, Reveri, and I should just mention, they didn't pay us for an ad read.

 I'm just telling you what they told me so that I can accurately reportwhat it costs to use Reveri.

 They have a monthly subscription to use the Reveri app at 14.

99.

 You do get the seven-day free trial.

 They have a yearly subscription of 99.

99 with a seven-day free trial.

 And they have a lifetimepurchase, one-time purchase, of 249 with no trial.

 It right now is only availablefor Apple, not for Android, but they are, yes, goingto have it available for Android soon.

 There's a signup list there.

 I should mention that whilethe cost might seem high, if you compare that costto, say, supplements, or you compare that cost to apoor night's sleep over time, the cost, at least to me,seems somewhat modest, certainly within rangefor a number of people.

 But I acknowledge not withinrange for other people, which is why I also wantto point to zero-cost tools and the zero-cost tool forgetting asleep, staying asleep, and falling back asleep is going to be NSDR.

 We'll put a link to anon-sleep deep rest protocol that's available on YouTube, so available to anybody zero cost provided you have a internet connection.

 Again, dim the screen if you're going to turnthat on late at night.

 And there are a number ofother yoga nidra scripts and apps and sources around the internet, in particular, on YouTube, that are zero cost that you could use if the Reveri app isoutside your price range or is not preferable to you, et cetera.

 When I wake up in the middle of the night, it's usually to use the restroom.

 I'll go use the restroom.

 I'll keep the lights as dim as possible.

 I'll get back into bed.

 And if I find that it'seasy to fall asleep, great, I'm asleep.

 And if not, then I willgenerally plug in the Reveri app.

 They have a fall back asleep hypnosis, and 99 times out of a hundred, I'm back asleep within minutes and I don't wake up until morning.

 Now, very briefly, I justwant to touch on some tools that are very commonly usedby many people out there, and believe it or not, there is peer-reviewed scienceon things like eye masks.

 Do eye masks improve yourability to stay asleep? And indeed, they do, provided they are not too tight and provided that the room is cool enough.

 Why? Well, eye masks cover theupper half of your face, which is where glabrous skin is localized.

 Remember, palms of thehands, bottoms of the feet, glabrous skin on the face.

 So a lot of people whowear eye masks will wake up because they're too warmif the room is too warm.

 So if you're going to use aneye mask to keep light out, definitely make sure the room and your sleeping environmentand your bed are cool enough in order for you to stay asleep.

 In addition, I get a lot ofquestions about earplugs.

 Here's the deal with earplugs.

 Some people find thatearplugs are very beneficial because, of course, theyprevent the entrance of sound into the ear that could wake us up.

 But some people find that the sound of their own beating of theirown heart can be disruptive and they get a sort ofhumming in their head when they have those earplugs in.

 I'm one such person.

 Although, I have family members that like using earplugs when they sleep.

 So it's really up to you.

 You have to see whetheror not those earplugs help or disrupt your sleep.

 For me, they're no good.

 For some people, they really enjoy them.

 I don't use an eye mask unless I'm sleeping in areally bright environment or I need to sleep on a planeand things of that sort.

 Other tools that I'll just mention that have peer-reviewedresearch to support them.

 Elevating your feet either with a pillow or by elevating the end of your bed by about three to five degrees can be really beneficial forincreasing the depth of sleep because of the so-calledglymphatic washout.

 This is the movement ofand circulation of fluids in your brain at night that lead to more wakefulness and actually can improvecognitive function and a number of other thingsrelated to brain health.

 There's one caveat to that.

 For people that suffer from acid reflux, having your ankleselevated above your chest or above your heart inthe middle of the night can actually exacerbate that acid reflux.

 You want to do the opposite.

 You want to actually elevatethe head side of your bed by about three to five degrees.

 Now, one of the commoncauses of sleep disruption that has tremendously detrimental effects is so-called sleep apnea.

 So this is basically bouts of suffocation or lack of oxygenation during sleep.

 This is particularly the case for people that are very heavyset, and that heavyset could be from obesity, it could also be heavysetfrom having too much muscle.

 A lot of people who arecarrying too much muscle will actually have sleepapnea without realizing it.

 Sleep apnea is actually very dangerous.

 It's associated with a numberof cardiovascular issues.

 It's associated with sexual dysfunction.

 It's associated withissues with cognition.

 Sleep apnea is bad.

 A lot of people will have to use the PAP, which is a, it's a device.

 It looks like a sort of likea snorkel mask or a dive mask.

 It's a whole apparatus thatpeople will go to sleep with.

 However, many people can relievethemselves of sleep apnea provided it's not too serious and can sleep much better, in fact, I think all peoplecan sleep much better, if they train themselves to be nose breathers while they sleep.

 There are a lot of reasonsto be a nose breather unless you are breathingvery hard due to exercise or talking or eating.

 That was all coveredin James Nestor's book, "Breath: The New Science of a Lost Art.

" It's been covered in anumber of different podcasts.

 We've talked about iton this podcast as well.

 It's a good idea to be a nose breather unless you need to mouth breathe.

 And it's a great idea, it's a superb idea, to be a nose breather in sleep.

 And one way to really get good at that is to take a little bit of medical tape and to tape your mouthshut before going to sleep.

 You heard me right.

 Put some medical tape over your mouth and force yourself tonose breathe during sleep.

 It also prevents snoring in most cases.

 Really offsets sleep apnea.

 Sleep apnea, again, being avery serious health concern.

 I should also mention as a tool that if you have a hard timebeing a nose breather in sleep, you can try doing yourcardiovascular exercise, at least the lower-intensitycardiovascular exercise, through purely nasal breathing.

 And one way to do that, again,is to tape your mouth shut or put a gulp of water in your mouth, but don't actually swallowthat mouth full of water, or to use a mouthpiece or just deliberatelykeep your mouth closed and insist on breathing through your nose.

 Most people find that when they start doingcardiovascular exercise that way, it's really challenging at first, but over time, theyactually can feel quite calm and still can generatea lot of physical effort purely using nose breathing.

 The reason that doing nose breathing during cardiovascular exercise translates to being anose breather during sleep is that your sinuses actuallycan dilate, they're plastic, and over time, plastic meaning they're malleable that is, and they can become wider.

 You're not going to get giantnostrils.

 Don't worry about it.

 Your airways within your skull, 'cause that's what the sinuses really are, these little passages within the skull, and, of course, within the nasal passages, will dilate and will allow you to breathe more easily through your nose.

 But for those of you that are waking up inthe middle of the night breathing on your back [breathing heavily] or your partner is telling you that or other people are telling you that or you're that person on the plane with your mouth hanging open and drooling and your mouth breathing, terrible, terrible,terrible for health reasons and other reasons, put some a medical tape over your mouth, learn to be a nose breather during sleep.

 Your sleep will improve and your daytime feelings of wakefulness and focus will improve, your cardiovascular health will improve, and on and on and on.

 So now we've largely coveredthe tools that one could use to get and stay asleep, and we talked about exercise, we talked about temperature, we talked about supplements, and we talked about, of course, keeping the sleeping environment both cool and as dark as possible.

 I do want to mention acouple of broad contour tools that will impact your ability to sleep really well on a consistent basis and the one that impactsthe most number of people is weekends.

 Turns out that mosteverybody feels the impulse to sleep in on the weekend, especially if they've beenout late the night before.

 However, the data show that keeping relativelyconsistent sleep and wake times is really going to enhance the quality and depth of your sleep.

 So if you stay out late one night, sure, you might allow yourself to sleep in an extra hour or so, but you should really tryto avoid sleeping in longer than an hour beyond yournormal wake-up time.

 That's right.

 If you normally get eight hours of sleep and you wake up at 7:00 a.

m.

, probably okay to wake upat 8:00 a.

m.

 on the weekend or after a night out the night before, but try not to sleep until 11 or noon thinking that you're goingto catch up on your sleep or that's better than wakingup at a consistent time.

 It would be better to wakeup at a consistent time plus or minus an hour and get a nap in the afternoon provided that nap, again, isn't too long.

 And the other tool that relates to nights thatyou stayed out too late or that you feel like youwant to sleep in a bit more in the morning is if you are going to wakeup at your consistent time.

 So for example, normallyyou go to bed at 10 and you wake up at six.

 Let's say that's your schedule.

 And you end up staying up late one night until midnight or one for whatever reason and the next morning you wake up at seven and you're still groggy.

 In that case, you absolutely want to wait to ingest caffeine 90 to120 minutes after waking.

 You really do because there are good data to support the fact thatcaffeine can disrupt sleep.

 Yes, that's obvious.

 Caffeine especially disrupts sleep if you take it too late in the day.

 That's very obvious as towhy that would be the case.

 But caffeine especially disrupts what's called compensatory sleep.

 So if you start changing your waking time and your to sleep time and you start using additional caffeine to offset the sleepinessthat you're experiencing because of those late nights out, well, that's when youreally start to disrupt not just your nighttime sleep, but your daytime compensatorysleep, so those naps.

 You also are disrupting thetotal architecture of sleep in the early morning hours.

 There's a lot of great sciencethat's been put to this, or that's emerged from this, I should say.

 So try and keep those sleep-waketimes relatively constant plus or minus an hour, and try as much as you canto delay that caffeine intake 90 to 120 minutes after waking every day, but especially on days where you wake up and you feel you haven'tgotten enough sleep.

 In that case, I highly recommend you just use NSDR or the Reveri app or some other form of deep relaxation to try and compensatefor the lack of sleep, knowing, of course, thatthere's no complete compensation for lack of sleep.

 There are just things that we can do to partially offset lack of sleep.

 Now, a couple of finalpoints and additional tools that I think are going tobe useful to everybody, in particular, peoplewho have young children or are following a shift work schedule or who are experiencing jet lag.

 Keep in mind, jet lagcan be due to travel, which is obvious, but jet lag can also be due to getting woken up in themiddle of the night, right? Your body doesn't know the difference between flying to a new time zone and getting woken up inthe middle of the night.

 The tool that I'd like to offer you is an understanding of somethingcalled temperature minimum.

 And I'm going to makethis as simple as possible and I'm confident thateveryone can understand this even if you don't haveany science background.

 Here's the question youneed to ask yourself.

 What is your typical wake-up time, okay? What's your typical wake-up time? If for you, your typicalwake-up time is 7:00 a.

m.

 plus or minus half an hour, and that could be 7:00 a.

m.

 because you set an alarm clock or it could be 7:00 a.

m.

 because you naturally wake upat 7:00 a.

m.

, doesn't matter, if your typical wake-uptime most days is 7:00 a.

m.

, well, then your temperatureminimum is 5:00 a.

m.

 That's right, your temperatureminimum is not a temperature.

 It's a time within your 24-hour cycle.

 Approximately two hours beforeyour typical wake-up time, your body is at its lowest temperature that it will ever be in the 24-hour cycle.

 That's why it's calledyour temperature minimum.

 Here's what you need to knowabout your temperature minimum.

 If you view bright light,exercise, or drink caffeine or all of the above in the two to four hours beforeyour temperature minimum, that will delay your clock.

 What that means whenI say delay your clock is it will make you wantto go to sleep later and wake up later the next night, okay? So let's run this exercise for you, the person waking up at 7:00a.

m.

 on a regular basis, I can predict with almost certainty that your body is going tobe at its lowest temperature at 5:00 a.

m.

.

 So what that means is that if you get up at3:00 a.

m.

 or at 4:00 a.

m.

 and you flip on brightlights in your house or in your bathroom or you have a cup of coffee or you do any kind of exercise or you get up and head to the airport, the mechanisms in your brain and body that control timing of sleep and timing of waking will shift.

 They will delay.

 It's as if you put your clockon hold for a little while and then let it start again, okay? That's the simplest way I can describe it.

 And you will tend towant to go to sleep later and wake up later the following night.

 Now, the opposite is true if you view bright light, drink caffeine, or exercise or socialize, I should say, in the hours immediately afteryour temperature minimum.

 So for you in this example, the person who's waking up at 7:00 a.

m.

, your temperature minimum is 5:00 a.

m.

, if you view bright light, exercise, maybe have a snack, maybenot, or socialize, move about, at 5:30 or 6:00 a.

m.

 or 7:00 a.

m.

 That will tend to phaseadvance your clock.

 It will tend to basically make you want to go to bed earlierand wake up earlier the following night.

 Now, I used this example of a person who wakes uptypically at 7:00 a.

m.

 whose temperature minimum is 5:00 a.

m.

, but, of course, you needto adjust that for yourself if you're somebody whowakes up at 9:00 a.

m.

 or at 5:00 a.

m.

 et cetera.

 Why do I offer this as a tool? Well, this is an immensely powerful tool if, for instance, youare headed to a time zone where you need to go to bed earlier and wake up earlier once youarrive in that time zone.

 What it means is in the dayor two before you leave, you can force yourself toexercise, drink caffeine, maybe even to eat a mealearly in the morning, or maybe you still fastearly in the morning and that's really up to you, but you force yourselfto do the activities that are going to phaseadvance your clock.

 Whereas if you're traveling to a time zone where you are going to needto go to sleep much later and you're going to needto wake up much later or even a little bit later, you can do those things in the hours prior toyour temperature minimum.

 Now, for those of youthat work shift work, this can be especially useful, but I want to say a coupleof things about shift work.

 There are a lot of detailsabout shift work and jet lag in an episode that I did specifically about jet lag and shift work.

 So for the deep dive, go there, but suffice to say this for now, if you are going to do shift work, try to stay on the same shiftfor two weeks at a time.

 It's very detrimental to brain and body, it can even be horrifically challenging for your brain and bodyin a number of ways, if you are switching onthe so-called swing shift, you know, you're workingthree days the night shift, three days the day shift, three days the nightshift, three days the.

.

.

 Try and stay on the sameschedule as much as possible.

 And I should say for everybody, people who are jet lagged andengaged in shift work or not, but just for everybody, if you need to be awake inthe middle of your sleep cycle and it's not just a quickdeparture to the bathroom and back to bed, but you really need to be awake, you know, you're feeding a baby or you're taking care of a loved one or you need to dosomething that's critical or you need to work, if possible, use red light, okay? Now, for shift workerswho really are trying to stay awake all night and sleep all day, this is not going to be ideal, but for people that, for instance, need to stay up really late one night or wake up especiallyearly, like 3:00 a.

m.

, to prepare for an exam thatyou're just not ready for or to head to the airport, et cetera, using red light has been shown to allow people to be awake enough and obviously see what they need to see in order to performtheir activities safely but it does not seem todisrupt the cortisol rhythm that is the healthy,normal cortisol rhythm.

 Now, I realize this iskind of an advanced tool and many people won't have access to this.

 There are a number of differentsources for red lights now.

 Companies like Joovv or KOZE light.

 These are different brands.

 I don't have any affiliation to any of these brands, I should say.

 There are a number of different red light bulb sources outthere and commercial sources that you can explore if you want.

 But understanding this temperature minimum is really powerful because it allows youto adjust your schedule depending on travel, depending on changing workschedules or school schedules.

 And if you're not a morning person, you can use the tools relatedto temperature minimum to really become amorning person over time, and it actually is pretty easy.

 And I talked about thisin a previous episode but I'll just mentionthat there have been shown to be important, positiveeffects on cognition, on even grip strengthand physical performance, for people that are early morning risers, and that's especially true for night owls that deliberately shiftthemselves to become early risers.

 Okay, so that's a lot ofinformation and a lot of tools and I suppose the one set of tools that I really didn'tdrill into too deeply, the ones related tojet lag and shift work.

 And again, please check out the episode on jet lag and shift workif that's relevant to you.

 But I think for most peoplewho are going to sleep at night and are trying their bestto sleep well at night and are trying their best to wake up in the morning at whatever hour and stay alert and focusedthroughout the day, maybe with a brief nap, the tools that I talked about today related to light,temperature, food, exercise, caffeine, supplements, and digital tools, I'm hoping will prove tobe very useful for you.

 They certainly are all supported by excellent peer-reviewed research.

 And I should just emphasize again that most of the tools we talked about are completely zero cost.

 So while the supplements andsome of the digital tools do carry some cost to them, I really want to encourage everybody to get your behaviors right.

 Get all of the things relatedto your timing of exercise and type of exercise in the best possibleorder and time of day.

 We talked about this criticalperiod early in the day and then another criticalperiod in the middle of the day and the late afternoon and then this third critical period in the middle of the night.

 Different tools for thedifferent three critical periods.

 I promise that if youstart to implement some, or ideally, all of these tools, the quality of your sleepwill increase tremendously.

 And of course, in doing so, the quality of your daytime alertness and your ability to focuswill improve tremendously.

 Again, sleep is the absolute foundation of your mental health,your physical health, and your performance in all endeavors.

 So if there's one area of your life to really focus on and try and optimize, if your goal is to behappier and more productive and just to have a better life overall, I can confidently say that sleep is reallythe thing to optimize.

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 During today's podcast and on many previous episodesof The Huberman Lab Podcast, we talked about supplements.

 While supplements aren'tnecessary for everybody, many people derivetremendous benefit from them for things like sleep and focus and hormone support and so forth.

 For reasons mentioned at thebeginning of the episode, we are now partnered withMomentous supplements.

 If you go to livemomentous.

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 They ship internationally, their quality is exceedingly high, and by largely focusingon single ingredient and various dosages ofdifferent supplements, you can create the optimizedsupplement protocol for you.

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 There, I cover scienceand science-related tools, some of which overlaps with the content of TheHuberman Lab Podcast, and other of which, I should say much of which, is distinct from the informationcovered on this podcast.

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 So thank you for joiningme today for our discussion about tools for optimizing sleep, and in doing so, tools foroptimizing not just sleep, but your daytime feelingsof alertness and focus and your overall health.

 And last but certainly not least, thank you for your interest in science.

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