Speaker 1: Welcome to Huberman Lab Essentials, where we revisit past episodes
Speaker 1: for the most potent and actionable science based tools for
Speaker 1: mental health, physical health, and performance. I'm Andrew Huberman, and
Speaker 1: I'm a professor of neurobiology and ophthalmology at Stanford School
Speaker 1: of Medicine. Today we're talking all about sleep and how
Speaker 1: to optimize your sleep. Let's consider what the perfect twenty.
Speaker 2: Four hour cycle would look like.
Speaker 1: Regardless of when you wake up in the morning, one
Speaker 1: of the first things that happens is that your body
Speaker 1: temperature is increasing, and that's just going to happen naturally.
Speaker 1: That increase in body temperature, in turn, causes an increase
Speaker 1: in the release of a hormone called cortisol. Cortisol is
Speaker 1: often con demonized and considered this bad thing, and indeed,
Speaker 1: you don't want cortisol to be chronically or consistently elevated
Speaker 1: throughout the day or night, but you do want cortisol
Speaker 1: to reach its peak early in the day, right about
Speaker 1: the time you wake up. One way that you can
Speaker 1: ensure that that cortisol peak occurs early in the day,
Speaker 1: right about the time that you wake up, is to
Speaker 1: view bright light, ideally from sunlight within the first thirty
Speaker 1: to sixty minutes after waking. The reason for that is
Speaker 1: very simple. You want to trigger that cortisol increase to
Speaker 1: occur very early in your day, and you don't want
Speaker 1: that cortisol peak to happen later, which is what will
Speaker 1: happen if you wait to get outside and see sunlight.
Speaker 1: The reason for this is that you have a set
Speaker 1: of neurons nerve cells in your eye. They're called intrinsically
Speaker 1: photosensitive melanops and cells, but you do not need to
Speaker 1: know that name. Those neurons respond best to bright light
Speaker 1: and especially right after waking.
Speaker 2: Early in the day.
Speaker 1: They are best able to signal to a set of
Speaker 1: neurons that reside over the roof of your mouth called
Speaker 1: the super chismatic nucleus, which is a cluster of neurons
Speaker 1: that then sends a huge number of other signals electrical
Speaker 1: and chemical, out to your entire body. That triggers that
Speaker 1: cortisol increase, provides a wake up signal for your brain
Speaker 1: and body, and sets in motion a timer for you
Speaker 1: to fall.
Speaker 2: Asleep later that night. Here's what you do, or at
Speaker 2: least here's what I do.
Speaker 1: I wake up in the morning and I want to
Speaker 1: reach for my phone, but I know that even if
Speaker 1: I were to crank up the brightness on that phone screen,
Speaker 1: it's not bright enough to trigger that cortisol spike and
Speaker 1: for me to be at my most alert and focused
Speaker 1: throughout the day and to optimize my sleep at night.
Speaker 1: So what I do is I get out of bed
Speaker 1: and I go outside. And if it's a bright, clear
Speaker 1: day and the sun is low in the sky or
Speaker 1: the sun is starting to get overhead what we call
Speaker 1: low solar angle, then I know I'm getting outside at
Speaker 1: the right time. Especially on cloudy days, you want to
Speaker 1: get outside and get as much light energy or photons
Speaker 1: in your eyes. But let's say it's a very clear
Speaker 1: day and I can see where the sun is, I
Speaker 1: do not need to stare directly into the sun. So
Speaker 1: the way to get this sunlight viewing early in the
Speaker 1: day is to look toward the sun. Never look at
Speaker 1: any light, sunlight or otherwise that's so bright that it's
Speaker 1: painful to look at because you can damage your eyes.
Speaker 1: But for this morning sunlight viewing, it's to not wear sunglasses.
Speaker 1: That's right, to not wear sunglasses. It is absolutely fine
Speaker 1: to wear eyeglasses or contact lenses, so called corrective lenses.
Speaker 1: In fact, those will serve you well in this practice
Speaker 1: or this tool because they will focus the light onto
Speaker 1: your neural retina and onto those melanopsin intrinsically photosensitive gangli
Speaker 1: and cells. This is grounded in the core of our physiology.
Speaker 1: There are literally hundreds, if not thousands, of quality peer
Speaker 1: reviewed papers showing that light viewing early in the day
Speaker 1: is the most powerful stimulus for wakefulness throughout the day,
Speaker 1: and it has a powerful positive impact on your ability
Speaker 1: to fall and stay asleep at night. So this is
Speaker 1: really the foundational power tool for ensuring a great night's
Speaker 1: sleep and for feeling more awake during the day. If
Speaker 1: you wake up before the sun is out, you can
Speaker 1: and probably should, flip on artificial lights in your internal
Speaker 1: home environment or apartment or wherever you happen to live.
Speaker 1: If your goal is to be awake, If you wake
Speaker 1: up at four in the morning and you need to
Speaker 1: be awake, well, then turn on artificial lights. If you're
Speaker 1: asking whether or not turning on artificial lights can replace
Speaker 1: sunlight at those hours, unfortunately the answer is no, unless
Speaker 1: you have a very special light. We'll talk about what
Speaker 1: kind of light the bright. Artificial lights in your home
Speaker 1: environment are not I repeat, are not going to be
Speaker 1: sufficiently bright to turn on the cortisol mechanism and the
Speaker 1: other wake up mechanisms that you need early in the day.
Speaker 1: The diabolical twist, however, is that those lights in your
Speaker 1: home or apartment, or even on your phone are bright
Speaker 1: enough to disrupt your sleep if you look at them
Speaker 1: too late at night or in the middle of the night.
Speaker 1: So there's this a symmetry in our retinal, our eye biology,
Speaker 1: and in our brains biology whereby early in the day,
Speaker 1: right around waking, you need a lot of light, a
Speaker 1: lot of photons, a lot of light energy, and artificial
Speaker 1: lights generally just won't accomplish what you need them to accomplish.
Speaker 1: But at night, even a little bit of artificial light
Speaker 1: can really mess up your so called circadian your twenty
Speaker 1: four hour clocks, and all these mechanisms that we're talking about.
Speaker 1: On cloudy days, you especially need to get outside, I repeat,
Speaker 1: on cloudy days, overcast days, you especially need to get
Speaker 1: outside and get sunlight. You just need to get more
Speaker 1: of it. Now, how much light and how much light
Speaker 1: viewing do you need? This is going to vary depending
Speaker 1: on person and place, literally where you live on Earth,
Speaker 1: whether or not there's a lot of tree cover, whether
Speaker 1: or not you're somebody has sensitive eyes or less sensitive eyes.
Speaker 1: It's really impossible for me to give an absolute prescriptive,
Speaker 1: but we can give some general guidelines in general. On
Speaker 1: a clear day, meaning no cloud cover or minimal cloud cover,
Speaker 1: you want to get this sunlight exposure to your eyes
Speaker 1: for about five.
Speaker 2: Minutes or so.
Speaker 1: Could be three minutes one day, could be seven minutes
Speaker 1: the next day, about five minutes. On a day where
Speaker 1: there's cloud cover, so the sun is just peeking through
Speaker 1: the clouds or it's more dense cloud cover, you want
Speaker 1: to get about ten minutes of sunlight exposure to your
Speaker 1: eyes early in the day. And on days that are
Speaker 1: really densely overcast or maybe even a rainy you're going
Speaker 1: to want to get as much which just twenty or
Speaker 1: thirty minutes of sunlight exposure. Just don't try and get
Speaker 1: this sunlight exposure through a windshield of a car or
Speaker 1: a window, whether or not it's tinted or otherwise. It takes
Speaker 1: far too long. It's simply not going to trigger the
Speaker 1: relevant mechanisms. Now, if you live in a part of
Speaker 1: the world where it's extremely dark and overcast, or the
Speaker 1: weather won't let you outside, or you live in a cave,
Speaker 1: there are sunlight simulators or daylight simulators that you can purchase.
Speaker 1: Those are quite expensive in general. Therefore, I suggest cheaper
Speaker 1: options that work just as well because they get just
Speaker 1: as bright, things like ring lights that are sold in
Speaker 1: order for people to take selfies in this kind of thing.
Speaker 1: A LED tablet will work pretty well. I actually have
Speaker 1: one of those, and I put it on my desk
Speaker 1: all morning, even though I still get outside and look
Speaker 1: at sunlight first thing in the morning. Again, also especially
Speaker 1: I should say on cloudy days. Many of our listeners
Speaker 1: live in locations throughout the world where, for instance, during
Speaker 1: the winter it gets very very dark, so they can't
Speaker 1: get sufficient sunlight. But get that morning light, ideally from sunlight,
Speaker 1: and take into account all the specific points that I've
Speaker 1: given you here. When you start doing this, you'll notice
Speaker 1: that your body will start to feel more energized, and
Speaker 1: it will feel more energized more quickly. You'll actually start
Speaker 1: this to notice this mechanism kicking in each day, especially
Speaker 1: if you're paying attention to your physiology. It's that diffuse
Speaker 1: very bright sunlight, that photon energy that you really want.
Speaker 1: That's going to set all the rhythms of your brain
Speaker 1: and body in the proper way, not just that cortisol peak,
Speaker 1: but it's going to trigger proper metabolism. It's going to
Speaker 1: set a timer for you to be able to fall
Speaker 1: asleep about sixteen hours later. It's also going to suppress
Speaker 1: any melatonin, a hormone that makes you sleepy that happens
Speaker 1: to be swimming around in your bloodstream at the time
Speaker 1: you wake up. It does a number of other things too,
Speaker 1: including interact with the adentisine system and kind of wash
Speaker 1: out some of the adentisine that might still be residual
Speaker 1: if you didn't sleep enough. Fundamentally speaking, get that morning
Speaker 1: sunlight viewing. I promise you will be grateful that you did.
Speaker 1: It makes everybody feel better, feel more alert, and it
Speaker 1: will greatly assist with your ability to fall and stay
Speaker 1: asleep later that night. I'd like to take a quick
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Speaker 1: You will also want to leverage not just light, but
Speaker 1: temperature as a tool. If you are inclined, it would
Speaker 1: be wise to try and increase your core body temperature
Speaker 1: a bit more quickly than it would otherwise if you
Speaker 1: were to just you know, shuffle around outside, get your
Speaker 1: sun light, maybe read a little bit, et cetera. And
Speaker 1: there are two main ways you can do that. The
Speaker 1: first way is to get into cold water of some sort.
Speaker 1: So this could be a cold shower of anywhere from
Speaker 1: one to three minutes. This could be an ice bath
Speaker 1: if that's your thing. It could be a cold tub,
Speaker 1: or if you own a cold tub that's specifically designed
Speaker 1: for deliberate cold exposure, get under some cold water. One
Speaker 1: to three minutes of cold water exposure will wake you
Speaker 1: up because of that adrenaline release. And and I want
Speaker 1: to highlight the and it will serve to increase your
Speaker 1: core body temperature.
Speaker 2: That's right.
Speaker 1: If you put something cold on the surface of your body,
Speaker 1: your brain, a little cluster of neurons in the so
Speaker 1: called medial preoptic area act as a thermostat and say, ah,
Speaker 1: the external of my body is cold, and therefore I'm
Speaker 1: going to heat up my core body temperature.
Speaker 2: So it's a little bit paradoxical.
Speaker 1: People think, oh, if you get into cold water or
Speaker 1: an ice bath, your body temperture is going to drop,
Speaker 1: and indeed that's true if you stay in for a while.
Speaker 1: But if you just get in for about one to
Speaker 1: three minutes, or under the cold shower for one to
Speaker 1: three minutes, your core body temperature will increase. So this
Speaker 1: is great for waking up and we have exercise. One
Speaker 1: of the best ways to increase your core body temperature
Speaker 1: early in the day is to do exercise. And I
Speaker 1: always say the best time to exercise, at least what
Speaker 1: the research points to is immediately when you wake up
Speaker 1: in the morning. It could be a walk so you
Speaker 1: can get your sunlight exposure while you're taking a walk
Speaker 1: first thing in the morning. It could be a light jog,
Speaker 1: it could be skipping rope, but try and get your
Speaker 1: core body temperature increased first thing in the morning. And
Speaker 1: a great way to do that is with the cold
Speaker 1: water and or with exercise. And again, it doesn't have
Speaker 1: to be your full blown workout for the day if
Speaker 1: you're doing workouts consistently, which I hope everybody is, because
Speaker 1: everybody really should exercise. Right now, you'll notice we're only
Speaker 1: focused on this early part of the day, and you
Speaker 1: might be saying, wait a second, I thought this was
Speaker 1: an episode.
Speaker 2: About tools for sleep.
Speaker 1: Well, everything that we're talking about doing in these first
Speaker 1: sixty to ninety minutes of the day really set in.
Speaker 2: Motion a wave of.
Speaker 1: Biological cascades that carry through the entire day and into
Speaker 1: the evening and into the night, and really do serve
Speaker 1: to optimize sleep. So just hang in there with me.
Speaker 1: So the next category of tool for use early in
Speaker 1: the day is caffeine.
Speaker 2: You do not have to drink caffeine.
Speaker 1: So what I'm about to describe are ways to leverage
Speaker 1: caffeine used to optimize sleep and wakefulness if you are
Speaker 1: comfortable with caffeine. Caffeine is something that a lot of
Speaker 1: people consume early in the day. How much depends on
Speaker 1: your tolerance, and there's a lot of individual variability here. Again,
Speaker 1: caffeine is a dniscene antagonist or effectively works as a
Speaker 1: dentistine antagonist and limits sleepiness. And for many people, shifting
Speaker 1: that caffeine intake from immediately after waking in the morning
Speaker 1: to ninety to one hundred and twenty minutes gives them
Speaker 1: a much longer arc of energy throughout the day and
Speaker 1: they don't feel the need to drink more caffeine later
Speaker 1: in the afternoon. If you do drink caffeine later in
Speaker 1: the afternoon, really try and limit the total amount, or
Speaker 1: drink decaf. Certainly keep the total amount to less than
Speaker 1: one hundred milligrams if you are interested in getting into
Speaker 1: the best possible sleep. And I say this knowing that
Speaker 1: many people, including myself, can drink a double espresso with
Speaker 1: two hundred milligrams of caffeine or more at five PM
Speaker 1: or even six pm or after dinner and still quote
Speaker 1: unquote fall asleep fine or still sleep fine. There are
Speaker 1: more and more papers all the time that point to
Speaker 1: the fact that caffeine intake late in the day, after
Speaker 1: four pm, that is, can really disrupt.
Speaker 2: The architecture of your sleep.
Speaker 1: So you might think you're sleeping well, but you're not
Speaker 1: sleeping nearly as well as you could if you avoided
Speaker 1: caffeine in those afternoon hours. Some of you might be
Speaker 1: doing your main bout of exercise first thing in the morning,
Speaker 1: and you want your caffeine before that bout of exercise.
Speaker 1: In that case, I say, go for it. I absolutely
Speaker 1: respect the fact that people have different work schedules, kid schedules,
Speaker 1: et cetera. So if you want to do some or
Speaker 1: none or all these tools, that's really up to you.
Speaker 1: I'm just providing them to you in the simplest form
Speaker 1: that I can possibly provide them. Now, the other lever
Speaker 1: or tool that you have available to you is food,
Speaker 1: not just what you eat, but when you eat. And
Speaker 1: it turns out that if you eat early in the day,
Speaker 1: you support a biological clock mechanism that will make you
Speaker 1: more alert early in the day. That said, many people
Speaker 1: choose to fast in the early morning hours of the
Speaker 1: day or in the first part of the day. I'm
Speaker 1: one such person. I generally don't ingest any food until
Speaker 1: about eleven AM or twelve noon. Sometimes I'll have breakfast
Speaker 1: if people are eating for brunch or breakfast. I will
Speaker 1: have breakfast for social reasons every once in a while,
Speaker 1: but most of the time I don't eat until about lunchtime. However,
Speaker 1: some people are really hungry when they wake up in
Speaker 1: the morning. Just know that if you eat early in
Speaker 1: the day, you are further triggering an increase in metabolism
Speaker 1: and in temperature that will make you more alert. So
Speaker 1: you don't have to eat early in the day. But
Speaker 1: you can start to see how these different tools layer together.
Speaker 1: Sunlight viewing, exercise, cold water eating, many of them are
Speaker 1: converging on the same mechanisms. In fact, when you drink
Speaker 1: caffeine there's also a small increase in body temperature due
Speaker 1: to the adrenaline increase that it stimulates. So all of
Speaker 1: these things can be layered on top of one another,
Speaker 1: or you can use them individually or think about them individually. Now,
Speaker 1: food is an interesting lever or tool because it's not
Speaker 1: just about when you eat, but it's also about what
Speaker 1: you eat.
Speaker 2: And I've talked a lot.
Speaker 1: About eating for energy and what that means in terms
Speaker 1: of caloric energy versus neural energy, et cetera in previous
Speaker 1: podcast episodes. We're not going to focus on that now
Speaker 1: because that's very nuanced. All that said, if you eat
Speaker 1: a very large meal, it doesn't matter if you slept
Speaker 1: terrifically well ten hours the night before, or if you
Speaker 1: are about to go to sleep, or if it's the
Speaker 1: middle of the afternoon, if your gut is full of food,
Speaker 1: there's just a large volume of food in your gut.
Speaker 1: It's going to divert a lot of blood and other
Speaker 1: critical resources away from other organs of your body, in
Speaker 1: particular your brain, and you're going to be sleepy after
Speaker 1: eating a big meal. So this is sort of a duh,
Speaker 1: But I think oftentimes in the discussions about what to
Speaker 1: eat for energy, people neglect to consider food volume as
Speaker 1: a strong parameter or variable in that discussion.
Speaker 2: So if you eat a huge breakfast, it's.
Speaker 1: Likely that you are going to be tired immediately after
Speaker 1: eating that breakfast, unless, of course, you exercise very hard
Speaker 1: prior to that and you metabolize all that food very quickly.
Speaker 1: So if you do decide to eat in the first
Speaker 1: few hours of the morning, just understand that you are
Speaker 1: setting or you're helping to set a food entrained as
Speaker 1: it's called circadian clock, light, temperature, timing of food intake, movement,
Speaker 1: and exercise. All of these things literally funnel in in
Speaker 1: a neural sense. They funnel into this thing that we
Speaker 1: call the circadian clock, and they let that clock, that
Speaker 1: set of neurons predict when you are likely to be
Speaker 1: eating an active and viewing sunlight the next day and
Speaker 1: the next day and the next day. So what all
Speaker 1: these tools do is they really set up a cascade.
Speaker 1: I'll think of it as kind of a wavefront of
Speaker 1: wakefulness and focus throughout the day. It'll take you through
Speaker 1: the middle of the day in the afternoon stage we'll
Speaker 1: talk about in a few minutes, but really they take
Speaker 1: you to this period that is about five PM until
Speaker 1: your bedtime, a second critical period in which you need
Speaker 1: to leverage particular tools in order to get and stay
Speaker 1: asleep optimally and to be able to sleep through the night.
Speaker 1: So really there are three critical periods throughout each twenty
Speaker 1: four hour cycle, and during each of those critical periods,
Speaker 1: you're going to want to do as many specific things
Speaker 1: as you can to optimize your wakefulness and focus and
Speaker 1: mood throughout the day and your sleep at night. The
Speaker 1: first critical period is the one that we've been talking
Speaker 1: about up until now. I think it's like morning sunlight, viewing,
Speaker 1: caffeine ninety one hundred and minutes after waking, exercise, and
Speaker 1: so on, and it really encompasses the time from which
Speaker 1: you wake up until about three hours after waking. The
Speaker 1: second critical period is the time throughout the day and
Speaker 1: afternoon leading into evening. So you may ask, what are
Speaker 1: the things that you can do throughout the day, the
Speaker 1: middle of your day and into the afternoon and evening
Speaker 1: hours that are really going to set you up for
Speaker 1: the best possible.
Speaker 2: Sleep later that night.
Speaker 1: Well, there are a few do's and there are a
Speaker 1: few don'ts. First of all, be careful about ingesting too
Speaker 1: much caffeine throughout the middle of the day. That's kind
Speaker 1: of an obvious one, for the reasons that we talked
Speaker 1: about earlier. Second of all, if you are a napper,
Speaker 1: and I raise my hand now for those of you listening,
Speaker 1: I'm raising my right hand because I love naps.
Speaker 2: I've always loved naps. Should you nap? Should you not nap?
Speaker 1: That's a question that I get asked a lot, and
Speaker 1: that I asked doctor Matthew Walker when he was a
Speaker 1: guest on this podcast. Here was his answer, and here's
Speaker 1: what the data support. It is fine to nap in
Speaker 1: the afternoon, but don't nap so late in the day
Speaker 1: or for so long that it disrupts your ability to
Speaker 1: fall and stay asleep at night for your major sleep bout.
Speaker 1: I should also say you do not have to to nap.
Speaker 1: Kind of an interesting phenomenon that happens on these podcasts
Speaker 1: in on social media where we'll talk about naps and
Speaker 1: the fact that naps are great and don't make them
Speaker 1: longer than ninety minutes. But then all the non nappers
Speaker 1: get really worried. Wait, am I supposed to nap? I
Speaker 1: don't like naps.
Speaker 2: I wake up Grogg. You do not have to nap.
Speaker 1: In fact, if you can make it through your whole
Speaker 1: day without napping, great more.
Speaker 2: Power to you.
Speaker 1: So this critical period throughout the day is one in
Speaker 1: which most people are doing a lot of stuff. They're
Speaker 1: emailing and picking up kids, and they're exercising, and they're
Speaker 1: commuting and doing all sorts of things, taking phone calls
Speaker 1: and zooms, et cetera. But if you can get that
Speaker 1: period of deep relaxation through a nap or NSDR, that's
Speaker 1: going to serve you well. Trying not to drink too
Speaker 1: much caffeine certainly no more than one hundred milligrams of
Speaker 1: caffeine after four pm.
Speaker 2: If your goal is to fall.
Speaker 1: Asleep at a reasonably normal time. And for those of
Speaker 1: you that exercise in the afternoon, understand that if you
Speaker 1: exercise very intensely, so this might be weight training or
Speaker 1: running or some other very intense exercise, typically that's going
Speaker 1: to further increase your body temperature and it's going to
Speaker 1: so called delay your circadian clock. It's going to make
Speaker 1: it such that you want to fall asleep a little
Speaker 1: bit later, maybe even a lot later. So if you're
Speaker 1: exercising in the afternoon or evening and that's the only
Speaker 1: time you can exercise, or that's the time that you
Speaker 1: prefer to exercise, great, just know that you are delaying
Speaker 1: your circadian clock. You are making it such that you
Speaker 1: will naturally want to go to sleep later and wake
Speaker 1: up later. Contrast that with if you exercise early in
Speaker 1: the day, say immediately after waking up, or in the
Speaker 1: first zero to four hours after waking in most cases,
Speaker 1: that's not going to shift your circadian clock much. This
Speaker 1: critical period two or second critical period, I should say,
Speaker 1: during the middle of the day is a time in
Speaker 1: which you should be doing certain things and avoiding doing
Speaker 1: certain things. So that raises the question of whether or
Speaker 1: not you should also be getting a lot of light,
Speaker 1: in particular sunlight throughout the day. Now, on the face
Speaker 1: of it, you might just think, yes, you, sunlight's great,
Speaker 1: provided we're not getting a sunburn and we're not staring
Speaker 1: at the sun and damaging our hour eyes. We should
Speaker 1: get as much sunlight as we possibly can. However, because
Speaker 1: light is such a powerful stimulus for controlling the time
Speaker 1: of your sleepfulness or sleepiness i should say, and wakefulness,
Speaker 1: we might want to be cautious about how much light
Speaker 1: we are viewing in the afternoon, in particular in the
Speaker 1: early evening hours. Well, turns out it's not so straightforward
Speaker 1: viewing so sunlight to the eyes, sunlight in the late
Speaker 1: afternoon and evening hours, so again depends on time of year,
Speaker 1: depends on location that you happen to be in. But
Speaker 1: getting some sunlight in your eyes for again, maybe five
Speaker 1: or ten, maybe thirty minutes, depending on how much cloud
Speaker 1: cover there is. Doing that in the afternoon serves an
Speaker 1: additional beneficial purpose, which is you inoculate your nervous system
Speaker 1: against some of the negative effects of bright artificial light
Speaker 1: or even dim artificial light. In the nighttime hours between
Speaker 1: ten pm and four am, which is really critical period three,
Speaker 1: and we'll talk about what to do and what to
Speaker 1: not do during critical period three of every twenty four
Speaker 1: hour cycle. But to make it very clear what I'm
Speaker 1: saying here, get that morning sunlight in your eyes, but
Speaker 1: also gets a sunlight in your eyes in the late
Speaker 1: afternoon and evening hours when the sun is at so
Speaker 1: called low solar angle when it starts to descend in
Speaker 1: the sky. Getting that sunlight in your eyes in the
Speaker 1: late afternoon and evening signals to that clock that it's
Speaker 1: evening time and that sleep is coming. It also serves
Speaker 1: as a second anchor that tells your brain and body, hey,
Speaker 1: it's evening.
Speaker 2: The sun is descending.
Speaker 1: Those yellows and blues and oranges that you see in
Speaker 1: the evening sunsets, those signal to your brain and body
Speaker 1: that evening is there and that night time is coming.
Speaker 1: And they're really establishing a second reference point or wavefront
Speaker 1: of biological signals that are going to optimize your nighttime
Speaker 1: hours and your transition into really terrific sleep. I'd like
Speaker 1: to take a quick break and acknowledge our sponsor ag One.
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Speaker 1: I started taking ag one and the reason I still
Speaker 1: take it every day is because AG one is, to
Speaker 1: my knowledge, the highest quality and most comprehensive of the
Speaker 1: foundational nutritional supplements on the market. AG one is designed
Speaker 1: to support things like gut health, immune health, and overall energy,
Speaker 1: and it does so by helping to fill any gaps
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Speaker 2: So now let's talk.
Speaker 1: About what I'm calling critical period three of each twenty
Speaker 1: four hour cycle. So this would be the period of
Speaker 1: time of late evening, so it might be six pm
Speaker 1: for some depending on when you go to sleep, or
Speaker 1: seven pm, extending into the hours in which you decide
Speaker 1: to get into bed and go to sleep, and then
Speaker 1: throughout the night. There are a number of things that
Speaker 1: you're going to want to do, and there are a
Speaker 1: number of things that you are going to want to
Speaker 1: avoid doing in order to optimize your sleep. First of all,
Speaker 1: you're going to want to avoid bright artificial lights of
Speaker 1: any color. Once the sun goes down, you would be
Speaker 1: wise to try and dim the lights in your indoor environment.
Speaker 1: If you are going to use light at night, and
Speaker 1: most people do, I would encourage you to use as
Speaker 1: little artificial light as is required to carry out the
Speaker 1: activities you need to require safely. If you're watching a
Speaker 1: television show or you're watching something on your computer, dim
Speaker 1: that screen way way down as dim as possible. While
Speaker 1: still of course being able to view what you need
Speaker 1: to view. That bright light exposure will absolutely quash any
Speaker 1: melatonin that happens to be circulating in your brain and body. Now,
Speaker 1: melotonin a lot of people think of as a supplement,
Speaker 1: but melatonin is naturally released as the evening comes about
Speaker 1: and into the night time hours. It's a hormone that
Speaker 1: makes you feel sleepy and allows you to fall asleep.
Speaker 1: So viewing bright light in the late evening hours and
Speaker 1: nighttime hours is really not good for your sleep quality
Speaker 1: and your ability to fall and stay asleep. So for
Speaker 1: most people, a simple rule of thumb is going to
Speaker 1: be avoid bright artificial lights of all colors, and in
Speaker 1: particular overhead bright artificial lights between the hours of ten
Speaker 1: pm and four am.
Speaker 2: Use only as.
Speaker 1: Much light as is absolutely necessary in order to carry
Speaker 1: out the routines and activities you need to carry out safely. Now,
Speaker 1: that's light, But as you recall, we also have this
Speaker 1: tool related to temperature, and you're probably not going to
Speaker 1: be surprised that the way to leverage temperature in the
Speaker 1: evening is the exact opposite of the way that you
Speaker 1: want to leverage temperature early in the day. Early in
Speaker 1: the day, temperature increases from cold showers or exercise wake
Speaker 1: you up. What that means is that taking a cold
Speaker 1: shower late at night is probably a bad idea. Rather
Speaker 1: taking a nice hot bath or a sauna, you might
Speaker 1: think would heat up your body, And indeed that's what
Speaker 1: happens if you stay in a very long time. But
Speaker 1: if you do hot tub or a hot bath or
Speaker 1: a sauna in the evening and you don't stay in
Speaker 1: for more than twenty or thirty minutes, and you get out,
Speaker 1: you take maybe a cool ish shower or a warm shower,
Speaker 1: then what happens is there's a compensatory cooling off of
Speaker 1: your core body temperature for the reasons we discussed earlier,
Speaker 1: and your body temperature will drop by one to three
Speaker 1: degrees and it will make it much easier to get
Speaker 1: into sleep. So, if you're somebody then enjoys hot baths,
Speaker 1: hot showers, or hot tubs, evening and night time is
Speaker 1: going to be the best time to do that. If
Speaker 1: your goal is to facilitate sleep, Similarly, you should try
Speaker 1: and make your sleeping environment pretty cool if not cold. Now,
Speaker 1: that doesn't mean you need to be cold while you're asleep.
Speaker 1: You can get under as many blankets as you need,
Speaker 1: but it's a good idea to make your sleeping environment cool.
Speaker 1: In fact, drop the temperature in that sleeping environment by
Speaker 1: at least three degrees. You'll be happy that you did.
Speaker 1: You're going to want to sleep in a relatively cool
Speaker 1: or cold sleeping environment and then layer on the blankets
Speaker 1: as needed to stay asleep. If you lower the temperature
Speaker 1: in your sleeping environment, so lower the temperature in that room,
Speaker 1: or use a controllable mattress cover that can cool down,
Speaker 1: like eight Sleep or something of that sort. It's naturally
Speaker 1: going to make your sleeping environment cooler. And if you're
Speaker 1: too warm under the blankets, all you have to do
Speaker 1: is extend a hand or a foot out from under
Speaker 1: those blankets. Whereas if the sleeping environment that you're in
Speaker 1: is too warm, there's very little you can do to
Speaker 1: cool off besides push off those blankets. But if the
Speaker 1: room is too warm, well, what are you going to do?
Speaker 1: You'd probably have to put your hands into some cool water,
Speaker 1: take a coolish shower or something for a couple of seconds.
Speaker 1: That's not very practical. I would be remiss if I
Speaker 1: didn't touch on alcohol and CBD and THHC. Many places,
Speaker 1: but not all, THC is illegal, although there are medical uses,
Speaker 1: and some places it's decriminalized. Other places it's legal. Alcohol,
Speaker 1: of course, is consumed almost as frequently as caffeine is consumed.
Speaker 1: The sleep that one gets after drinking alcohol is greatly disrupted.
Speaker 2: Sleep. THCHC and alcohol do help.
Speaker 1: Some people fall asleep and maybe even stay asleep, the
Speaker 1: architecture of that sleep is suboptimal compared to the sleep
Speaker 1: they would get without alcohol or THHC in their system.
Speaker 1: So I'm not here to tell you what to do
Speaker 1: or not to do. I'm certainly not the substance police.
Speaker 2: That's not my role.
Speaker 1: I'm just reporting to you the biology. If your sleep
Speaker 1: is not restoring you to the extent that you feel
Speaker 1: it should, or if you are regularly relying on a
Speaker 1: drink or two in order to fall asleep or THHC
Speaker 1: in order to fall asleep, that is disrupting your total
Speaker 1: pattern of sleep. Okay, so you've done everything correctly up
Speaker 1: until now. You get your morning routine from critical period one,
Speaker 1: got your afternoon routine. You saw some sunlight in the afternoon,
Speaker 1: You avoided caffeine in the eight hours or ten hours
Speaker 1: before bedtime, you're not drinking alcohol, You've cooled down the room,
Speaker 1: you're doing all these things right, you've dimmed the lights,
Speaker 1: et cetera, et cetera. What else can we do in order.
Speaker 2: To optimize our sleep?
Speaker 1: I always say behavioral tools first, then look to nutrition, then,
Speaker 1: if necessary, look to supplementation, and then, if still necessary,
Speaker 1: look to prescription drugs obviously prescribed by a board certified physician.
Speaker 1: There are supplements that for most people will greatly improve
Speaker 1: their ability to fall and stay asleep. And the three
Speaker 1: main supplements in that category or that kit of sleep supplements,
Speaker 1: and I've talked about these before, are magnesium three on
Speaker 1: eight so t h R E O n A t e,
Speaker 1: apigenin a p I G E n I n, and
Speaker 1: theanine th h e A n I n E theanin.
Speaker 1: You don't necessarily need to take all three, although many
Speaker 1: people get a synergistic effect from taking all three. You
Speaker 1: may not even need to take even one. What I
Speaker 1: recommend is that if you're already doing all the behavioral
Speaker 1: tools regularly and you're still having trouble falling asleep and
Speaker 1: staying asleep, well, then you might try one of the
Speaker 1: supplements within this sleep stack, they do have fairly wide
Speaker 1: margins for safety, although I should also say anytime you're
Speaker 1: going to add or remove something from your supplement protocol
Speaker 1: or your nutritional program, you definitely want to talk to
Speaker 1: your physician. I don't just say that to protect us,
Speaker 1: I say that to protect you. For most people, the
Speaker 1: margins of safety on these things are going to be
Speaker 1: pretty broad. For some people, the dosages of any one
Speaker 1: or several of the supplements I mentioned will be zero.
Speaker 1: That is, you won't need them in order to get
Speaker 1: and stay asleep most nights of your life. For many people, however,
Speaker 1: taking one hundred and forty five milligrams of magnesium three
Speaker 1: on eight can be very beneficial. Some people need to
Speaker 1: go a little higher, some people need to go a
Speaker 1: little bit lower. Fifty five zero milligrams of apagenin and
Speaker 1: again you could just take the apagenin on its own,
Speaker 1: and one hundred to four hundred milligrams of thionine taken
Speaker 1: again alone or in combination with the other supplements mention.
Speaker 1: This stack, many people find allows them to get really
Speaker 1: drowsy and fall asleep, sleep really deeply, and they feel
Speaker 1: much more refreshed the next day.
Speaker 2: And they don't have a groggin.
Speaker 1: About five percent of people report that magnesium three in
Speaker 1: eight really disrupts their gut it gives them diarrhea or
Speaker 1: gastric distress, in which case don't take it.
Speaker 2: Now.
Speaker 1: In a slightly different way, many people who can tolerate
Speaker 1: magnesium three and eight or really thrive on magnesium three
Speaker 1: and eight and like apagenin, might find that theanine, even
Speaker 1: at the lowest dose of one hundred milligrams, because again
Speaker 1: the range is one hundred to four hundred milligrams, that
Speaker 1: theenine gives them such vivid dreams that they actually find
Speaker 1: it disruptive, or they wake up in the middle of
Speaker 1: the night, or they find that the sleep that they're
Speaker 1: getting is kind of anxiety ridden because of the intensity
Speaker 1: of those dreams. So some people might choose to leave
Speaker 1: theoine out of the sleep stack and just take magnesium
Speaker 1: three and eight ra apagenin. Again, some people might leave
Speaker 1: magnesium three and eight out of the sleep stack. All
Speaker 1: of this is really about finding the supplementation protocol that's
Speaker 1: ideal for you. I should mention that whether or not
Speaker 1: you're taking one or two or three of the components
Speaker 1: of the sleep stack. The ideal time to take those
Speaker 1: is thirty to sixty minutes before bedtime. That sleep stack
Speaker 1: can be very beneficial to people, and I do think
Speaker 1: that it's preferable to melatonin. First of all, melotone is
Speaker 1: a hormone that you indogenously make. The dosages of melatonin
Speaker 1: that are contained in most commercial products is far, far,
Speaker 1: far greater than what we would make indogenously, so it's
Speaker 1: really supra physiological. So that's of concern because melatonin is
Speaker 1: not just responsible for making a sleepy and fall asleep.
Speaker 1: It also does things like interacts with other hormone systems
Speaker 1: to stosterone and estragon, even in the puberty system. In kids,
Speaker 1: is taking melotone every once in a while a problem
Speaker 1: for adjusting to jet lag, etc. Probably not even say no,
Speaker 1: but taking it chronically over time, especially kids taking it
Speaker 1: chronically over time, can potentially be problematic. I'd like to
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Speaker 1: a slight degree of dehydration can diminish cognitive and physical performance.
Speaker 1: It's also important that you get adequate electrolytes. The electrolytes sodium, magnesium,
Speaker 1: and potassium are vital for functioning of all the cells
Speaker 1: in your body, especially your neurons or your nerve cells.
Speaker 1: Drinking Element disolved in water makes it very easy to
Speaker 1: ensure that you're getting adequate hydration and adequate electrolytes. To
Speaker 1: make sure that I'm getting proper amounts of hydration and electrolytes,
Speaker 1: I dissolve one packet of Element in about sixteen to
Speaker 1: thirty two ounces of water when I first wake up
Speaker 1: in the morning, and I drink that basically first thing
Speaker 1: in the morning. I'll also drink Element dissolved in water
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Speaker 1: I love the raspberry, I love the citrus flavor. Right now,
Speaker 1: Element has a limited addition lemonade flavor that is absolutely delicious.
Speaker 1: I hate to say that I love one more than
Speaker 1: all the others. But this lemonade flavor is right up
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Speaker 1: If you'd like to try Element, you can go to
Speaker 1: drink Element dot com slash Huberman spelled drink lnt dot
Speaker 1: com slash Huberman to claim a free Element sample pack
Speaker 1: with a purchase of any Element drink mix. Again, that's
Speaker 1: drink Element dot com slash Huberman to claim a free
Speaker 1: sample pack. I do want to mention a couple of
Speaker 1: broad contour tools that will impact your ability to sleep
Speaker 1: really well on a consistent basis, and the one that
Speaker 1: impacts the most number of people is weekends. It turns
Speaker 1: out that most everybody feels the impulse to sleep in
Speaker 1: on the weekend, especially if it's been out late the
Speaker 1: night before. However, the data show that keeping relatively consistent
Speaker 1: sleep and wake times is really going to enhance the
Speaker 1: quality and depth of your sleep. So if you stay
Speaker 1: out late one night, sure you might allow yourself to
Speaker 1: sleep in an extra hour or so, but you should
Speaker 1: really try to avoid sleeping in longer than an hour
Speaker 1: beyond your normal wake up time. It would be better
Speaker 1: to wake up at a consistent time plus or minus
Speaker 1: an hour and get a nap in the afternoon, provided
Speaker 1: that nap again isn't too long. Now, a couple of
Speaker 1: final points and additional tools that I think are going
Speaker 1: to be useful to everybody, in particular people who have
Speaker 1: young children, or following a shift work schedule, or who
Speaker 1: are experiencing jet lag. Keep in mind, jet lag can
Speaker 1: be due to travel, which is obvious, but jet lag
Speaker 1: can also be due to getting woken up in the
Speaker 1: middle of the night. Right your body doesn't know the
Speaker 1: difference between flying to a new time zone and getting
Speaker 1: woken up in the middle of the night. The tool
Speaker 1: that I'd like to offer you is an understanding of
Speaker 1: something called temperature minimum. And I'm going to make this
Speaker 1: as simple as possible, and I'm confident that everyone can
Speaker 1: understand this, even if you don't have any science background.
Speaker 1: Here's the question you need to ask yourself, what is
Speaker 1: your typical wake up time? If your typical wake up
Speaker 1: time most days is seven am, well, then your temperature
Speaker 1: minimum is five am.
Speaker 2: That's right.
Speaker 1: Your temperature minimum is not a temperature, it's a time
Speaker 1: within your twenty four hour cycle. Approximately two hours before
Speaker 1: your typical wake up time, your body is at its
Speaker 1: lowest temperature that it will ever be in the twenty
Speaker 1: four hour cycles. That's why it's called your temperature minimum.
Speaker 1: Here's what you need to know about your temperature minimum.
Speaker 2: If you view bright.
Speaker 1: Light, exercise, or drink caffeine or all of the above
Speaker 1: in the two to four hours before your temperature minimum,
Speaker 1: that will delay your clock. What that means when I
Speaker 1: say delay your clock, is it will make you want
Speaker 1: to go to sleep later and wake up later the
Speaker 1: next night. Okay, so let's run this exercise for you,
Speaker 1: the person waking up at seven am. On a regular basis,
Speaker 1: I can predict with almost certainty that your body is
Speaker 1: going to be at its lowest temperature.
Speaker 2: At five am.
Speaker 1: So what that means is that if you get up
Speaker 1: at three am or at four am, and you flip
Speaker 1: on bright lights in your house or in your bathroom,
Speaker 1: or you have a cup of coffee, or you do
Speaker 1: any kind of exercise, or you get up and head
Speaker 1: to the airport, the mechanisms in your brain and body
Speaker 1: that control timing of sleep and timing of waking will shift.
Speaker 2: They will delay it.
Speaker 1: Says if you put your clock on hold for a
Speaker 1: little while and then let it start again. That's the
Speaker 1: simplest way I can describe it, and you will tend
Speaker 1: to want to go to sleep later and wake up
Speaker 1: later the following night. Now, the opposite is true. If
Speaker 1: you view bright light, drink caffeine, or exercise or socialize,
Speaker 1: I should say in the hours immediately after your temperature minimum.
Speaker 1: So for you in this example, the person who's waking
Speaker 1: up at seven am, your temperature minimum is five am.
Speaker 2: If you view bright.
Speaker 1: Light, exercise, maybe, have a snack, maybe not, or socialize
Speaker 1: move about at five point thirty or six am or
Speaker 1: seven am. That will tend to phase advance your clock.
Speaker 1: It will tend to basically make you want to go
Speaker 1: to bed earlier and wake up earlier the following night.
Speaker 1: Now use this example of a person who wakes up
Speaker 1: typically at seven am, whose temperature minimum is five am.
Speaker 1: But of course you need to adjust that for yourself
Speaker 1: if you're somebody wakes up at nine am or at
Speaker 1: five am, et cetera. Why do I offer this as
Speaker 1: a tool, Well, this is an immensely powerful tool. If,
Speaker 1: for instance, you're headed to a time zone where you
Speaker 1: need to go to bed earlier and wake up earlier
Speaker 1: once you arrive in that time zone. What it means
Speaker 1: is in the day or two before you leave, you
Speaker 1: can force yourself to exercise, drink caffeine, maybe even to
Speaker 1: eat a meal early in the morning, or maybe you
Speaker 1: still fast early in the morning.
Speaker 2: And that's really up to you.
Speaker 1: But you force yourself to do the activities that are
Speaker 1: going to phase advance your clock. Whereas if you're traveling
Speaker 1: to a time zone where you are going to need
Speaker 1: to go to sleep much later and you're going to
Speaker 1: need to wake up much later, even a little bit later,
Speaker 1: you can do those things in the hours prior to
Speaker 1: your temperature minimum. And I should say for everybody, people
Speaker 1: who are doing jet who are jet lagged and engage
Speaker 1: in shift work or not, but just for everybody. If
Speaker 1: you need to be awake in the middle of your
Speaker 1: sleep cycle, you know you're feeding a baby, or you're
Speaker 1: you're taking care of a loved one, or you need
Speaker 1: to do something that's critical, or you need to work,
Speaker 1: use red light.
Speaker 2: And now for shift workers who really are trying.
Speaker 1: To stay awake all night and sleep all day, this
Speaker 1: is not going to be ideal. But for people that,
Speaker 1: for instance, to stay up really late one night, or
Speaker 1: wake up especially early, like three am, to prepare for
Speaker 1: an exam that you're just not ready for, or to
Speaker 1: head to the airport, etc. Using red light has been
Speaker 1: shown to allow people to be awake enough and obviously
Speaker 1: see what they need to see in order to perform
Speaker 1: their activity safely. But it does not seem to disrupt
Speaker 1: the cortisol rhythm, that is the healthy, normal cortisol rhythm. Okay,
Speaker 1: so that's a lot of information and a lot of tools,
Speaker 1: and I really want to encourage everybody to get your
Speaker 1: behaviors right, get your nutrition right. For you, I promise
Speaker 1: that if you start to implement some or ideally all
Speaker 1: of these tools, the quality of your sleep will increase tremendously,
Speaker 1: and of course, in doing so, the quality of your
Speaker 1: daytime alertness and your ability of focus will improve tremendously. Again,
Speaker 1: sleep is the absolute foundation of your mental health, your
Speaker 1: physical health, and your performance in all endeavors. And last,
Speaker 1: but certainly not least, thank you for your interest in science.