Huberman LabDr. Matt Walker: Protocols to Improve Your Sleep | Huberman Lab Guest Series
EVERY SPOKEN WORD
155 min read · 30,513 words- 0:00 – 1:16
Improving Sleep
- AHAndrew Huberman
Welcome to the Huberman Lab Guest Series, where I and an expert guest discuss science and science-based tools for everyday life. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today marks the second episode in our six-episode series all about sleep, with our expert guest, Dr. Matthew Walker. During today's episode, we discuss the dos and the do-nots of sleep, focusing, for instance, on how to use light and absence of light, as well as temperature, both of your sleep environment, specifically the room you're in, your body temperature, and much more in order to regulate the timing and quality of your sleep. And we discuss how things like alcohol, caffeine, and cannabis impact sleep and the various stages of sleep. And we discuss the various tools that exist now and that are rapidly becoming available to improve your sleep. This episode is essential for anyone trying to optimize their sleep. And when I say optimize your sleep, I mean trying to optimize the formula that was addressed in the first episode of this series, which is the QQRT formula, the quality, quantity, regularity, and timing of your sleep. Four variables that combine to determine whether or not your sleep is optimized for you, and thereby providing the most restoration and improvement to your mental health, physical health, and performance.
- 1:16 – 5:30
Sponsors: Helix Sleep, WHOOP & Waking Up
- AHAndrew Huberman
Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is, however, part of 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 the sponsors of today's podcast. Our first sponsor is Helix Sleep. Helix Sleep makes mattresses and pillows that are customized to your unique sleep needs. It's abundantly clear that sleep is the foundation of mental health, physical health, and performance. When we're getting enough quality sleep, everything in life goes so much better, and when we are not getting enough quality sleep, everything in life is that much more challenging. And one of the key things to getting a great night's sleep is to have the appropriate mattress. Everyone, however, has slightly different needs in terms of what would be the optimal mattress for them. Helix understands that people have unique sleep needs, and they've designed a brief two-minute quiz that asks you questions like, do you sleep on your back, your side, or your stomach? Do you tend to run hot or cold during the night? Or maybe you don't know the answers to those questions. If you go to the Helix site and take that brief quiz, they'll match you to a mattress that is optimal for you. For me, it turned out to be the Dusk, D-U-S-K, mattress. It's not too hard, not too soft, and I sleep so much better on my Helix mattress than on any other type of mattress I've used before. So if you're interested in upgrading your mattress, go to helixsleep.com/huberman, take their brief two-minute sleep quiz, and they'll match you to a customized mattress for you, and you'll get up to $350 off any mattress order and two free pillows. Again, that's helixsleep.com/huberman to save up to $350 off and two free pillows. Today's episode is also brought to us by Whoop. Whoop is a fitness wearable device that tracks your daily activity and sleep, but also goes beyond that by providing real-time feedback on how to adjust your training and sleep schedule to perform better. I've been working with Whoop on their Scientific Advisory Council to try and help advance Whoop's mission of unlocking human performance. As a Whoop user, I've experienced the health benefits of their technology firsthand for sleep tracking, for monitoring other features of my physiology, and for giving me a lot of feedback about metrics within my brain and body that tell me how hard I should train or not train, and basically point to the things that I'm doing correctly and incorrectly in my daily life that I can adjust using protocols, some of which are actually within the Whoop app. Given that many of us have goals such as improving our sleep, building better habits, or just focusing more on our overall health, Whoop is one of the tools that can really help you get personalized data, recommendations, and coaching toward your overall health. If you're interested in trying Whoop, you can go to join.whoop.com/huberman today to get your first month free. Again, that's join.whoop.com/huberman. Today's episode is also brought to us by Waking Up. Waking Up is a meditation app that has hundreds of different meditations, as well as scripts for yoga nidra and non-sleep deep rest, or NSDR, protocols. By now, there's an abundance of data showing that even short daily meditations can greatly improve our mood, reduce anxiety, improve our ability to focus, and can improve our memory. And while there are many different forms of meditation, most people find it difficult to find and stick to a meditation practice in a way that is most beneficial for them. The Waking Up app makes it extremely easy to learn how to meditate and to carry out your daily meditation practice in a way that's going to be most effective and efficient for you. It includes a variety of different types of meditations of different duration, as well as things like yoga nidra, which place the brain and body into a sort of pseudo-sleep that allows you to emerge feeling incredibly mentally refreshed. In fact, the science around yoga nidra is really impressive, showing that after a yoga nidra session, levels of dopamine in certain areas of the brain are enhanced by up to 60%, which places the brain and body into a state of enhanced readiness for mental work and for physical work. Another thing I really like about the Waking Up app is that it provides a 30-day introduction course, so for those of you that have not meditated before or are getting back to a meditation practice, that's fantastic, or if you're somebody who's already a skilled and regular meditator, Waking Up has more advanced meditations and yoga nidra sessions for you as well. If you'd like to try the Waking Up app, you can go to wakingup.com/huberman and access a free 30-day trial. Again, that's wakingup.com/huberman. And now for my conversation with Dr. Matthew
- 5:30 – 12:05
Basics of Sleep Hygiene, Regularity, Dark & Light
- AHAndrew Huberman
Walker. Professor Matt Walker, welcome back. We're all so happy to have you here, and in episode one, you beautifully described the biology of sleep, why sleep is important, what happens when we don't get enough sleep, and you incentivized getting adequate amounts of great sleep, and you defined what great sleep is, and you provided some excellent practical protocols and tools for getting great sleep. However-
- NANarrator
(laughs)
- AHAndrew Huberman
... today, you're going to tell us, I believe, about the protocols for really optimizing your...... one's sleep, both conventional tools and protocols and some, let's say, unconventional-
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
... not heretical, but unconventional tools for optimizing one's sleep. So let's start with the basics. What are the basics of what I think I've heard you refer to pre- previously as sleep hygiene?
- MWMatthew Walker
Yeah, I think we- w- many of us can resonate with the idea of dental hygiene, (laughs) but turns out there's something called sleep hygiene. And there are probably, I would say, five edicts of sleep hygiene. I offer them as, as tools n- and not necessarily rules, because I don't think people respond to rules. People respond to reasons and not rules. So if it's okay, I'll probably just unpack each one of them rather than just sort of bark them at you and hope people assume that it's the right, uh, answer. I'll explain the answer so people understand why it's important. So as I said, there are probably five things that you can start doing tonight to try to improve your sleep. The first, we've spoken a little bit about in that first episode. It's part of the four macros of good sleep. First piece of advice, regularity. Go to bed at the same time and wake up at the same time. No matter whether it's the weekday or the weekend, regularity is king, and the reason is because when you feed your brain the signals of timed regularity for your sleep, it will anchor your sleep and improve the quantity and the quality of that sleep, because part of that signal of regularity going into your brain in terms of that repeated behavior night after night, sleep in other words, helps train that central 24-hour circadian clock that we also spoke about in the first episode. So that's the first piece of advice. Try to keep it as regular as you possibly can. The second piece of advice is darkness. In my view, we are a dark-deprived society in this modern era, and we need darkness at night, as well you've spoken about, to release a hormone called melatonin, and melatonin will help time the regular onset of your sleep. So that sounds great, but what boots on the ground mat, what does that mean? I would suggest the following. In the last hour before bed, try to dim down 50%, if not more, of your lights in your home, and you will be quite surprised at how sleepy and soporific that will make you feel. I will do this in a regimented way. I have, uh, a little reminder that pops up and tells me, "Now is the time to dim the lights based on your bedtime." And I'll go around and I'll shut lights down. In my bedroom, I will actually have a smart light bulb, and it is way down to probably as little as maybe five lux when... And lux is just a, a metric of th- the light. Um, it's way down there and it's also very deep orange, sort of red, and we can come on to why that's the case. So that's the first thing. Even before you're thinking about sleep, start to decrease the light. For example, if you were there at, let's say, for a standard sleep schedule, at 10:00 PM and normally you are getting into bed at 10:30 PM, but you feel pretty wide awake. If there was an electrical blackout and you lost your phone ma- magnetic too, phone goes down, lights go down, total blackout, my suspicion is that fairly soon you'd say, "Gosh, I actually feel quite sleepy." Whereas if the lights were blazing, you've got your phone, television's on, lots of stimulation, you're probably going to think at 10:30, "No, I could, I could probably push through for at least another hour." So try to dissipate that light, and then if you need to, wear an eye mask, blackout curtains always good as well. But we need that darkness at night because when you give the brain the signal of darkness, it releases effectively a brake pedal. That brake pedal has normally been applied by way of light on the release of that spigot of melo- melatonin, and when you take the brake pedal off, it starts, starts pumping out into the brain. You can also then, of course, probably reverse engineer this trick in the morning, and this is another component of why you've been, I think so, such a wonderful advocate for light in the morning. It does many things, but one of the things that it does is reapply that brake on melatonin and therefore you lose the signal to your brain of darkness. That's what melatonin, in some ways is doing. We often call it the hormone of darkness or the vampire hormone, not necessarily 'cause it makes you look longingly at people's necklines and want to, to, to bite in, which i- i- is great if you're into that, but it's really simply about it's releasing melatonin which tells the brain, "My goodness, it's nighttime." But if you've got bright light on, you come from your office, you're driving home so you've got artificial light during the day, which is probably not strong enough to stimulate you and bring you awake. You come home and you've got again bright light, but it's still strong enough now to prevent the release of melatonin. You start to shift in your timing and you may have problems with your sleep. So that's the second piece of advice.
- 12:05 – 18:45
Light, Day & Night; Cortisol, Insomnia
- MWMatthew Walker
I would love to ask you about that morning light too and the alertness benefits. I'm-... as a sleep researcher more focused on the evening component of light and decreasing it. But you've done a great job. I don't know if there's anything...
- AHAndrew Huberman
Yeah, th- there are a couple of quick points that, um, are based on some what I consider really nice studies. Uh, there's beautiful work in humans showing that bright light exposure in the morning, especially from sunlight, but, um, if one doesn't have access to sunlight for whatever reason, there are commercially available so-called SAD lamps, seasonal effective disorder lamps. They range anywhere from 5,000 to 10,000 lux, very bright.
- MWMatthew Walker
Wow, yeah.
- AHAndrew Huberman
But, um, but certainly, uh, morning sunlight viewing and lamps of the sort I just described have been shown to increase the amplitude of the morning cortisol spike by as much as 50%, five-zero. So people hear cortisol, and they freak out.
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
They think, "That's not good, I want my cortisol low." But you actually want your cortisol highest in the morning and lower in the afternoon and evening.
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
Um, and there's a lot of reasons for that, elevated mood, focus, and alertness in the morning and throughout the day, and, uh, ease of getting to sleep at night, lower anxiety, lower depressive symptoms, and so on. So that bright light also serves to, um, control the amplitude of cortisol, uh, in- in the direction you want in the early part of the day. The other thing that's just more of a, uh, underlying dynamics of the circadian visual system, which is a system that I worked on for years, um, these wonderful, um, cells in the eyes that are not for image forming, but rather for detecting sunlight and bright light for sake of setting circadian rhythm, is that the sensitivity of that system early in the day is actually quite low, so you need a lot of bright light early in the day to effectively wake up your system and shut down the sleepiness signals, such as melatonin. But later in the day, it's a rather diabolical system, it takes very little light, even from artificial sources, to disrupt your circadian rhythm and quash melatonin. As little as 15 seconds of bright light in the evening, I think Chu- Chuck Czeisler's laboratory at Harvard Medical School...
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
... showed can quash melatonin in the evening. Now, I don't want people to freak out and think that if they go into a hotel bathroom, which oftentimes those are very bright, in the middle of the night, flip on the light, that they're going to, um, completely, uh, screw up their circadian rhythms. But if I'm honest, they'd be much better off using, um, their phone as a flashlight to navigate. People always say, "Well, wait, but the flashlight on the phone is very bright." But let's just get logical here. A light shone into your eyes, if, uh, uh, such as a- a flashlight, is very different than looking at a flashlight beam on the ground.
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
Far and away difference. So the point is that if you don't get enough bright sunlight or light in your eyes early in the day, and then you're indoors under artificial lighting, you might think, "Well, this is really bright lighting. This is the kinda lighting that could disrupt my circadian rhythm at night, and therefore it's sufficient to wake up my system." No.
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
Early in the day and throughout the day, you need a lot of bright light, as much as safely possible to avoid sunburn and things of that sort, which you don't want. But then as the evening comes around, after sundown, you need very little artificial light in order to disrupt your circadian rhythm. And then just very quickly, light from candles, fireplaces is okay. This is kind of interesting. It seems bright, it's- but the w- but the measurements, uh, indicate that that's not gonna shift your circadian rhythm much. Candles are great, but of course don't burn your house down. So the- the orange and red tones in the evening way dimmed down, that's the way to go. Early in the day, bright, bright, bright light, as bright as you safely can tolerate.
- MWMatthew Walker
And what I like about firstly your mention of cortisol, you described how cortisol is rising in the morning, and that's a great thing, and it is a good thing, and in the evening it's starting to drop. And if you look right around your prototypical bedtime, and we're going to speak later in this episode as to what your real natural bedtime is versus (laughs) the one that you may be taking right now, it's very interesting. Cortisol will almost hit its lowest point, something that we call its nadir, it's the lowest point in that trough of its decline, right around the time when you should be sleeping. However, there's a great study that looked at people with insomnia, and in, uh, subsequent episodes we'll- we'll discuss this too, but o- one of the ways that we think about or conceptualize insomnia is in two different flavors, sleep-onset insomnia, "I can't fall asleep," and sleep maintenance insomnia, "I wake up, I can't get back to sleep." And what they looked at was essentially cortisol levels. They had, um, a catheter in the arm, and they were sampling it from the bloodstream, and they were able to do that every 30 minutes. So it's a little bit like time lapse photography, and you're getting a data point every 30 minutes across the 24-hour period looking at cortisol across now a full 24-hour period. And sure enough, when you look at healthy controls who can sleep well and insomnia patients, they look almost identical across the day. But then when it comes to falling asleep right around that bedtime period, the healthy controls are going all the way down. The insomnia patients go down, and down, and down, and then they have a rise back up right around that sleep onset period, and then they start to drop back down again just as the control group. But then they also often will have a spike in the middle of the night which then comes down, and then both of them are staying low throughout the early morning period, and then it starts to rise back up. So it's not as though net-net overall there is a higher level of cortisol in people with insomnia. It seems to be right at those trigger zones that map very nicely to sleep onset problems, sleep maintenance problems.
- AHAndrew Huberman
Very interesting. As somebody who wakes up in the middle of the night and sometimes has trouble getting back to sleep, that- that resonates. I- I have no trouble falling asleep whatsoever.
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
Um, knock on wood.
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
Not superstitious about this at this point. But I use tools like non-sleep deep rest, yoga nidra, long exhale breathing. But I, you know, I, and I think these wake-up...... uh, episodes seem to happen more when I'm processing a lot of stuff from my daily life.
- MWMatthew Walker
That's right.
- AHAndrew Huberman
You know, it, it's, um, the unconscious brain, um, oftentimes is working through things and, and will wake us up.
- MWMatthew Walker
Yeah. I often think that sleep maintenance insomnia that you've just described is the revenge of daytime emotions unresolved. (laughs)
- AHAndrew Huberman
Mm. That's a great way to put
- 18:45 – 26:05
Temperature; “Walk It Out”; Alcohol & Caffeine
- AHAndrew Huberman
it, yeah.
- MWMatthew Walker
So that would be, so we've spoken about regularity, we've spoken about darkness, and we've spoken about the inverse of that in the morning, which is light, a little bit of cortisol. So the third out of the five is going to be temperature, and the advice here is keep it cool. As we mentioned a little bit in the first episode, and we will go into great detail when we speak not just about these conventional and unconventional tips, but we're also going to go into the future of science and where sleep science is taking us to, in fact, optimize and even enhance our sleep. We will speak a lot about temperature. Suffice to say that you need to drop your core body temperature and your brain temperature by a little less than one degree Celsius, two to three degrees Fahrenheit, to get to sleep and stay asleep. The general target that we have in sleep science, if you look across the literature, is somewhere around about the 67 degree Fahrenheit or, I'm trying to do the calculation, maybe 18.5-ish degrees Celsius. Now, I know that that sounds cold, and cold it, it is, but you can also wear thick socks to bed, you can have a hot water bottle at the end of the bed. That's great too, but the ambient must be cold. The fourth piece of advice is walk it out. And here what I mean is do not stay in bed for long periods of time awake, and I think we mentioned this perhaps in the first episode too. When you are awake in your bed for long stretches of time, because your brain is an incredibly associative device, it will quickly learn that, that this thing called my bed is the place where I'm awake and not asleep. And what you need to do is break that association. If you've learned that time and time again because you've stayed in bed, and the rule of thumb, and it's just a, uh, a rule of thumb, about 20, 25 minutes, if you, you can't fall back asleep or you can't fall asleep, it's okay. Just say, "Well, tonight is not my night. It's not a problem. It's, tomorrow is not completely shot. It's fine. I'm just going to get up, get out of bed." If you can, if you're lucky enough, try to go to a different room and in dim light read a book, listen to a podcast, whatever it is that relaxes you, just do that. Don't check email. Don't eat because if you start eating, that again, trains your brain to start waking up and feeding at that time. And only return to bed when you are sleepy, and there is no time limit for that. I don't want you to come back after half an hour when you are still awake and not feeling sleepy enough. Why? Because you're gonna get back into bed and be in the same problem again. And gradually if you do this, and it's hard to do it, you will relearn the association that you had, I'm sure as a child, which is that your bed is this place of sleepiness, because often people will be saying, "I f- I feel so tired in the evening." And then they get into bed and they say, "But now I can't fall asleep at all. I don't understand it." In part it's because of that learned association. So that would be the fourth tip. The fifth tip, um, makes me, um, even more unpopular as a personality and character, which is try to be mindful of your alcohol and caffeine. Now, in a subsequent episode, we'll go into great detail as to how caffeine works, its mechanisms, why it is sleep disruptive, and why, in fact, I've even perhaps changed my mind on caffeine and, and its benefits, but it also does have significant detriments to your sleep. So the rule of thumb here would be try to cut yourself off from caffeine probably at, uh, least 10 or so hours before you expect to go to bed and you can just calculate back, calculate that, and try to limit it. So the dose and the timing make the poison. Cut yourself off after maybe two or three cups of coffee and then that timing component, count yourself back, cut yourself off. Decaffeinated coffee, not too bad if you find the right thing too, if you need that fix. Alcohol is probably one of the most misunderstood sleep aids in, uh, quotes, th- that there is. It is no sleep aid at all. Now, if I didn't understand what I know about alcohol and, and sleep, I would think that too, which is, look, when I have a nightcap just before bed or two, um, even though I don't wear them, um, I, I may actually just fall asleep very easily. Uh, it feels like I stay asleep very soundly across the night. So it's a great sleep aid and it really helps me. There are at least I would say three issues with alcohol. The first is that alcohol is in a class of drugs that we call the sedatives and sedation is not sleep, but when you take onboard alcohol in the evening, you mistake the former for the latter and you think it helps you fall asleep. The second thing is that because it's sedation, or actually it's probably related to sedation, if I were to show you the electrical signature of your deep sleep when you're...... just sleeping naturally, versus when you have alcohol in your system. It's not really the same. It's not a naturalistic form of deep sleep. It mimics it, it looks not too dissimilar. But if I really do my analyses and I, almost like that Pink Floyd album where I take the white light of electrical brain activity coming from your head as you're sleeping and split it apart into all of the different components, there are some components that are no longer present or some that are abnormally present. The second issue with alcohol is that it fragments your sleep, so it will litter your sleep with all these punctuated awakenings throughout the night. The danger there is that many of those awakenings with alcohol you don't remember, because they're too brief. But then you wake up the next day and you think, "Well, I didn't have a problem falling asleep, I didn't have a problem staying asleep, but I just, I feel rough, I just don't feel restored by my sleep," and you don't add two and two together. The final concern with alcohol is that it's quite a potent blocker of your rapid eye movement sleep, or REM sleep, and in subsequent episodes we'll go into great detail as to the incredible learning and memory creativity benefits that come by way of REM sleep. Also, it's essential for our emotional regulation and recalibrating our moods. So, for all of those reasons I would say two things. First, if you are struggling with sleep, not feeling restored by your sleep, keep in mind your alcohol intake, and also just in general be mindful of that if you are thinking about your sleep and want to preserve it.
- AHAndrew Huberman
So
- 26:05 – 29:43
Sleep Association, Bed vs. Sofa
- AHAndrew Huberman
much of what you just said resonates. Uh, I confess that in my lifetime I've had periods of, um, pretty spectacular sleep.
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
I characterize myself as somebody that could fall asleep anywhere, anytime.
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
But I've also experienced the extreme challenges of sleep, and, um, and that relates to different things, life circumstances, et cetera. In fact, recently I've had some challenges with sleep despite using the protocols that I and, uh, others suggest. I, I hadn't heard some of the things that you're, um, referring to here. And, um, middle of the night waking has become more of an issue. I communicated this to a former girlfriend of mine who, um, was, uh, I was in a relationship with when I was a, a junior professor, meaning before I got tenure.
- MWMatthew Walker
Mm-hmm.
- AHAndrew Huberman
And she said, "You don't remember, you had a p- uh, Andrew," but I do, "you had a pattern back then of, um, after I would fall asleep, you would continue working on your laptop, probably on grants-"
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
"... um, and then I would fall asleep working." And then according to her, I would wake up in the middle of the night and work a little bit until I'd get tired again and then fall asleep, and then this would repeat.
- MWMatthew Walker
Ah.
- AHAndrew Huberman
So, um, really stamping down the, uh, the associative learning element that you talked about before. So that was probably the first-
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
... period of time in my life in which I, I created this, um, rather, uh, deleterious association of work in the middle of the night in bed, right? Um, and then more recently I've had the, the, uh, experience of waking up, probably due to these, like, daytime things that I, I'm waking up in the middle of the night thinking about, and now because of our discussion during the course of r- of recording this series, I get out of bed after even 10, 15 minutes-
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
... um, so that I can start to eliminate that association. And another piece is that I've always felt that when I get out of bed in the middle of the night because I can't sleep and I go to the sofa, I often can sleep very well. Proving-
- MWMatthew Walker
And the reason being?
- AHAndrew Huberman
Proving, right, it's a control experiment proving that the location of sleep is, uh, e- the, and the association of wakefulness and sleep i- in bed as opposed to on the sofa is, is a clear component. And this is in an environment that's of equal temperature, I mean, it's not a perfect experiment, right? Um, it's anecdata, as we say. But I, I think that the associative piece is, oh, so strong, um, for many people, and so this is something to, to really take seriously.
- MWMatthew Walker
I love that notion of, um, people will often say, "I just get up. I go to the couch or the sofa, and that's where I'll wake up in the morning." Also they'll say, "When I travel and I go to a hotel room, I just can sleep fine." Now for some people it's the inverse, but for those people it's the contextual difference, meaning the change of the environment is so unfamiliar that it is not being bound to association of wakefulness. It's related to sleep, or at least the opportunity to sleep. Sometimes even, I've heard from some people, and we, there's no studies or data on this, even turning yourself around, now this is hard if you have a partner in bed, but you just switch top to bottom of the bed and you take your pillow and you pull the duvet all the way down and you put the pillow at the opposite end where your feet used to be and you get into bed, and even just looking around and sort of having a difference, uh... That alone is so subtle but it can make a real difference. So again, just keep these things in mind. I know it sounds strange, all, this whole sort of get up, get out of bed, break the associat- uh, and we'll come
- 29:43 – 35:23
Tool: Falling Asleep; Meditation, Breathing
- MWMatthew Walker
onto something, uh, well actually I'll come onto it now because I think it's one of the unconventional tips, and you mentioned it. A lot of people say to me, "That all sounds great. I, the science makes sense. I just don't want... It's dark, it's kind of cold, I really don't want to get out of bed. So give me some alternatives." I think the, the single best piece of unconventional sleep advice I can give you is do anything that gets your mind off itself. The principal reason that if you look at insomnia as a physiological condition, our current working model mechanistically of how insomnia, um, plays out is that you are in this state of almost low level anxiety-... and you are somewhat stressed. And when you go to sleep or you try to go to sleep or you wake back up and you try to get back to sleep, you just have this Rolodex of anxiety. In the modern world, we are constantly on reception and very rarely do we do reflection. And unfortunately for many of us, and I've been guilty of this, the only time we do reflection is when our head is placed on the pillow and we turn the light out, and that is the last time you want to be doing reflection. That's the worst moment. And at that point, I think everyone can empathize with the idea of you turn the light out, you're under stress, your mind goes to those few things. In the darkness of night, thoughts become almost 10 times worse than they do in the bright of day. And at that moment, you start to ruminate. When you ruminate, you begin to catastrophize. And when you catastrophize, you're dead in the water for the next two hours. So what do you do? The problem is, as I said, your mind is on itself and it's going through these repeated loops. Anything you can do, for example, you can do some kind of a meditation. And I, when I was researching data for my book some years ago, I did look into meditation and I wasn't a meditator, I was a hard-nosed scientist, I'm, uh, didn't really kind of embrace with that notion or even that, um, that group of people. But time and again, I read paper after paper and the data was very strong and it was coming from research groups that I respected very much indeed. So I thought, "Well, okay, I should probably give this a try." And that was six years ago. And since then, I now meditate for 10 minutes every single night before bed. I do a guided meditation 'cause I'm not particularly skilled so I use an app that moves me through that. But you can do whatever you, h- have whatever meditation you like. That's one example. The second example is you can do breathing methods because again, you're focused on your breath and what are you not focused on? Your thoughts. (laughs) And so anything that will allow you to, um, explore some other focus, maybe it's a body scan where you start at the top of your head or you start at your feet and you work your way up and you just say, "You know, moving through now my neck, what sensations am I feeling? Now into my shoulders, moving down into my chest now and I could feel the ends of my fingers. Am I sensing anything?" And when you start doing that or any of these types of things, the next thing that you remember is your alarm going off in the morning because you got your mind off itself. So, I would say that that's probably one of the unconventional tips, but let me come back to the conventional. Anything else I've probably missed out or been unclear about there? Um, actually, I should probably say one thing in terms of these, not, they're not tips. I don't like the word and I, I know you don't either or hacks or, um, these are protocols and they're well-informed scientific protocols. In all of this discussion today, you can get all of these things in place and still have problems with sleep. The reason is because you may be suffering from a sleep disorder. So, the analogy would be, let's say that I'm your athletic coach and you're a sports superstar. I can perfect everything. I can perfect your, y- your diet, your supplements. We can perfect your technique. We can perfect... But if you've got a broken ankle, none of those things are going to alter your performance right now. You've got to get to a doctor and get that seen to, and then we can come back to fine-tuning your performance. It's the same with sleep. If you've got a sleep disorder such as snoring, sleep apnea, or insomnia, we need to get you to a doctor first and then only after that, come back once you're resolved, then we can start to optimize. Uh, that's the only other thing I probably should mention.
- AHAndrew Huberman
Yeah. This is all very useful discussion because I think that, um, of course there will be those folks out there that just, like, "What are they talking about? I sleep so well at night." You know, consider yourself blessed. Many, many people struggle with, uh, challenges with sleep, and I think it's fair to say that sooner or later most everybody experiences some challenges with sleep for whatever reason.
- MWMatthew Walker
If you look at the statistics, that's highly likely. In your lifetime, you are more than likely to go through either a period of challenging sleep or in fact a bout of insomnia.
- 35:23 – 36:37
Sponsor: AG1
- MWMatthew Walker
- AHAndrew Huberman
I'd like to take a brief break and acknowledge our sponsor, AG1. AG1 is a vitamin mineral probiotic drink that also contains adaptogens and is designed to meet all of your foundational nutritional needs. By now, I'm sure you've all heard me say that I've been taking AG1 since 2012 and indeed that is true. Now, of course, I do consume regular whole foods every day. I strive to get those foods mostly from unprocessed or minimally processed sources. However, I do find it hard to get enough servings of fruits and vegetables each day. So with AG1, I ensure that I get enough of the vitamins, minerals, prebiotic fiber and other things typically found in fruits or vegetables, and of course, I still make sure to eat fruits and vegetables, and in that way provide a sort of insurance that I'm getting enough of what I need. In addition, the adaptogens and other micro-nutrients in AG1 really help buffer against stress and ensure that the cells and organs and tissues of my body are getting the things they need. People often ask me that if they were gonna take just one supplement what that supplement should be and I always answer, "AG1." If you'd like to try AG1, you can go to drinkag1.com/huberman to claim a special offer. You'll get five free travel packs plus a year supply of vitamin D3K2. Again, that's drinkag1.com/huberman.You
- 36:37 – 40:01
Alcohol & Sleep Disruption
- AHAndrew Huberman
talked about alcohol. Uh, I'm not a consumer of alcohol anymore.
- MWMatthew Walker
Mm-mm.
- AHAndrew Huberman
Um...
- MWMatthew Walker
Nor am I, and it's not, I, it's not 'cause I have anything against it.
- AHAndrew Huberman
Yeah, many people do enjoy it and, um, and no, uh, e- we're not calling judgment on, on them.
- MWMatthew Walker
Not at all.
- AHAndrew Huberman
I mean, certainly much of the world en- enjoys, uh, alcohol. Could we talk a little bit more about, um, aside from demolishing REM sleep, um, you know, w- do we know that alcohol causes these disruptions in sleep directly, meaning by changing the, um, pattern of release of neurotransmitters like GABA, things of that sort? Or is this an indirect effect? You know, is this, like, through the gut microbiome that then impacts sleep? Um, and the reason I ask is maybe we could get to some more specific, uh, dos and do not protocols. So for instance, if somebody wants to have a cocktail, how close to sleep can they get and, uh, not diminish their rapid eye movement sleep too much? You know, because people are still going to want to drink. Um, and with that said, if people do have a couple of drinks and then they, they go to sleep, is the, is there anything they can do prior to sleep to, uh-
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
... try and rescue, um, their, some of their quality sleep?
- MWMatthew Walker
Great question. So in terms of the mechanism, it seems actually not to be the alcohol, but some of the metabolic byproducts of alcohol. We think that perhaps the main culprit may be some of the aldehydes that are the metabolic, um, separate consequences of, uh, alcohol metabolism. You make a good point though in terms of the, the, the dose response timing curve. How late or how early do I have to cut myself off from alcohol? People have done those studies and they have found that even an afternoon single glass of wine, if you measure sleep in the way that we measure it at my center with high fidelity, you can see compromises and impairments. I wish I could tell you otherwise. I would say that based on that data, the principle protocol advice I would have for you is go to the pub in the morning. That way, by the time you're about to sleep, the alcohol is out your system and you could... No, no, I would never, as a, as a public scientist, I would never advocate necessarily for morning. I'm just kidding you, but um, that's, that's sort of one of the unfortunate consequences. There does seem to be an impact. To say that there isn't is just me not being truthful about the data. But again, if you, uh, think about the trade-off here, if you're going out or you're having friends over and you're gonna make an incredible evening of memories and you're going to open a favorite bottle of wine and have a couple of glasses of wine, is your sleep going to be compromised? Yes, it is. But maybe that's worth the trade-off for that specific night. I would just not wish you to, and you've spoken a, a lot and so has our dear friend Peter Attia and others, there just doesn't seem to be any safe amount of alcohol. Um, but I would say think about that trade-off. Simply, however, don't make it a habit that you're doing it, you know, multiple nights a week or more. That would probably be the advice.
- 40:01 – 49:25
Food & Sleep, Carbs, Melatonin
- MWMatthew Walker
- AHAndrew Huberman
Great. What about food and sleep? Um, how close to sleep, um, is it okay to have a meal if you want to optimize your sleep?
- MWMatthew Walker
Mm-hmm.
- AHAndrew Huberman
Um, I, I like to eat my final meal somewhere around 6:30 PM but, and I-
- MWMatthew Walker
That's about 3:00, 2:00 PM-
- AHAndrew Huberman
... go to sleep somewhere around 8:30, 9:00 PM.
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
In an ideal world. Sometimes I go to sleep a bit later. Um, sometimes I eat a little bit later. It's just, you know, there's some variability with these. But, um, put differently, what is the relationship between food intake and sleep quality in terms of timing of food intake? And then perhaps we can talk a little bit about, um, food macronutrients.
- MWMatthew Walker
It's very interesting. There was somewhat of a dogma out there that we have to stop eating, you know, three or four hours before bed for optimal sleep. If you look at the data, the data is quite a spread, no pun intended. There is, there are some people for whom that works very well and if they eat even two hours before bed, they just get disrupted in terms of their sleep. Some of that is about people just feeling too full and not feeling comfortable. Other aspects are that when you become recumbent, when you lie down, you have a higher risk of gastric reflux coming back up and therefore you get heartburn and that's pretty miserable and people will describe that too by way of closer proximity of food intake relative to when you're falling asleep. Nevertheless, if you look at the data, and I, I did a recent very deep dive on this personally myself about 12 months ago, it's not quite as extreme as the dogma makes out. If you eat two hours before bed, on average, it doesn't seem to necessarily harm your sleep. Now that's very different than saying what is best to improve or enhance your sleep, but the way these studies were designed, it was looking at detriments. They then went to 90 minutes before sleep onset and even there, there didn't seem to be marked impairments. 60 minutes you started to see maybe some signs, but on average the effect size was somewhat weak. But then when you get close to sort of 45 minutes or so, then things did start to deteriorate. I think it depends hugely on your chronotype and also just on your appetite circadian rhythm preferences too. I am someone who-I do not feel very hungry when I first wake up in the morning. I don't feel very hungry throughout most of the day, and I will onboard most of my calories probably in the hours, probably in about a four-hour period, maybe less, even three-hour period, and then I will cut myself off about 90 minutes before sleep. So I, classically, I would've been considered as, you know, violating this sleep dogma of, of cutting yourself off at least three hours. I think it's very personal though. Just experiment with it. You will know the situation. Um, as for macros and specific food components, the data is a little bit mixed. Certainly what we know is that if you're eating a diet that is high in sugar and low in protein, your sleep is worse. Why would that be the case? Well, one of the reasons that we think is that if you onboard sugar, it can be somewhat metabolically active, and when it becomes metabolically active, it can increase your body temperature, your core body temperature, even just very subtly, but that's enough to disrupt your sleep as we spoke about with temperature. But I think in terms of really the, you know, what would be the ideal macronutrient and even micronutrient, um, dietary recommendation that I would have for you, I don't think we have enough data yet above and beyond that, that statement. Um, yeah.
- AHAndrew Huberman
Yeah. I, I've experienced, um, when I eat a very low carbohydrate diet, which I've experimented with in the past, maybe even full ketogenic diet for sh- for brief periods of time, although I'm an omnivore, so I eat meat and eggs, and I also eat starches, pastas, rice, et cetera. Um, but we know based on beautiful work from, for example, Chris Palmer from-
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
... um, from Harvard Medical School, uh, who was a guest on this podcast.
- MWMatthew Walker
I listened to that. It was great podcast.
- AHAndrew Huberman
Yeah. Chris is, is spectacular and, and, uh, has advocated the exploration of ketogenic diets for the treatment of various psychiatric conditions. Not all, but psychiatric conditions. And, and it seems, and he agreed with me on this, that when people go on very low starch, very low carbohydrate diets, that sometimes they can experience a bit of hypomania. Some people can and, and, and challenges with sleep, and, um, sometimes there are psychiatric reasons why, um, people stay on those diets anyway, and then they have to do other things to encourage their sleep, either pharmacology or supplementation or some combination. But I, I can say anecdotally for myself, if I, if I don't eat starches for a extended amount of time, a couple of days, I find it very hard to get quality sleep-
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
... as, uh, indicated by sleep trackers, um, and, uh, and just, uh, sleep late- latency to fall asleep is longer than it is, et cetera. Um, so I've, I've opted to eat most of my carbohydrates later in the evening, um, which, kind of, violates, you know, every rule of, you know, eat your carbs early in the day. And, and I think there are some data to support that eating carbohydrates early in the day may actually, um, have certain benefits for weight maintenance or weight loss. So I, I realize that... But those aren't my, my goals at the moment. Uh, weight maintenance, yes, weight loss, no. So I think, um, I certainly feel after eating a dinner that has a bit more starch, pasta, rice, these things of that sort, and a little bit lower protein as opposed to the inverse, like eating a couple of rib- ribeye steaks and a salad, but no starch, that, um, my sleep is substantially better. Um, and I always, uh, attributed that to the relationship between some of the starches and the tryptophan/serotonin pathway.
- MWMatthew Walker
Yeah. There is some data on that with the carbohydrate intake in the evening, and of course, that, that tryptophan and that carbohydrate intake, um, will contain the precursor ingredients to something else that we've spoken about, which is melatonin. And so that may actually help healthily boost that melatonin signal. There's a little bit of data on that to support it too. We also did a study where we, um, we were looking at night to night to night sleep and carbohydrate intake the next day, and it did seem to support what you're describing in terms of some of the carbohydrate benefits. We also found a strange result that was almost the opposite prediction that we made. Carbohydrate intake in the morning too equally help people wake up, and we were a little bit uncertain as to why, but we're going to go into more detail. The reason that you mentioned the, the suggestion of not take on carbs in the evening is in part based on the evidence that your body's ability to dispose of sugar, and obviously when you're eating carbohydrate, you can have a higher, um, spike of sugar. Now that in part depends on what you're eating with that carbohydrate and also, of course, the nature of that carbohydrate, whether it's simple or whether it's complex, whether it's simple sugars versus, you know, complex more, um, starchy s- uh, carbohydrate. But the idea is that your body, even if you were to eat the same amount of carbohydrate in the morning, in the afternoon, or in the evening, same carbohydrate dose and type, but your body's ability to dispose of that without having excessive spikes of glucose is worse in the evening, better in the morning, i.e., if you're concerned about your blood sugar, um, and your metabolic health, maybe that's what you should do. I think that that data is unclear on the basis of if you are, um...... glycemic normal, meaning that you currently do not have signs of type 2, 2 diabetes or you're not pre-diabetic, then that may not necessarily be the case. And so I think that's why it could be, you know, beneficial for you, and I know that you've, um, you think deeply about that and, and, um, I've even been tracking blood sugar as well. I don't have any signs of it, but I'm just fascinated by some of that data and how it interacts with my sleep because I'm a, a sleep nerd. So I think right now we just don't have plentiful data to recommend a particular sleep, quote unquote, "diet" for improved optimization. I would say though that we can be a little bit more relaxed about the timing of our food.
- 49:25 – 55:52
Caffeine; Afternoon Coffee, Nighttime Waking
- MWMatthew Walker
- AHAndrew Huberman
Earlier you mentioned caffeine, and caffeine is a topic that we get into, into substantial depth in episode three, but there and now, I, uh, I will emphasize that caffeine is the most commonly used drug worldwide.
- MWMatthew Walker
Mm-hmm.
- AHAndrew Huberman
I think the statistic says that 90-plus percent of adults consume caffeinated beverages every day, which is remarkable, and a few years back, I recall there was an article in The Economist that charted the countries for which the caffeine consumption was highest, and way out on the-
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
... peak, peak, peak of m- uh, it was almost tr- uh, triple or quadruple what other, what the second place country, um, consumed each day, was, can you guess the country that consumes the most caffeine? Could be tea, coffee, any form.
- MWMatthew Walker
I'm going to suggest it's a Scandinavian country.
- AHAndrew Huberman
No, but, uh, but they're, they're up, they're up there. It was Switzerland. Now, I don't know if that's still the case, but apparently the Swiss-
- MWMatthew Walker
Oh, I, the reason I went-
- AHAndrew Huberman
... pe-
- MWMatthew Walker
... I was thinking it was S- 'cause I've seen the graph-
- AHAndrew Huberman
Right.
- MWMatthew Walker
... and I was thinking it was Sweden-
- AHAndrew Huberman
Right, so appar-
- MWMatthew Walker
... but it's a Scandinavian-
- AHAndrew Huberman
Yeah, and if I have that wrong-
- MWMatthew Walker
Okay. Ah. Come on, Wokeup.
- AHAndrew Huberman
... um, certainly someone will put it in the, the comments on YouTube-
- MWMatthew Walker
No, I'm sure you're right and I was wrong with Sweden.
- AHAndrew Huberman
... but, but as I recall, the Swiss drink so much caffeine they have, uh, a lot to think about. So I love caffeine. I drink black coffee, black espresso, and yerba mate. Um, I love yerba mate. I've been drinking it since I was a, a little one-
- MWMatthew Walker
Mm-hmm.
- AHAndrew Huberman
... um, 'cause of the Argentines in my family. Um, and I drink it in the early part of the day, typically, um, a couple hours after waking or so I'll have my first, um, sip of caffeine, and then I try to stop drinking caffeine somewhere around noon or 1:00 PM. Occasionally I'll have a shot or two of espresso in the early afternoon if there's important work to be done and I need to do that, but I, I've noticed that even that can alter my sleep in ways that, that I don't like. But the afternoon coffee for some reason tastes so much better than the morning coffee for me.
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
I don't know what it is. So it's coffee, yerba mate packed early into the day, and a lot of it for me.
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
I have a high tolerance for it, um, but then I let it taper. Is that an optimal contour of caffeine intake? Um, would zero caffeine be better? If someone's just really committed to sleep and they don't like caffeine, would zero be better than any? And what about that afternoon coffee or tea containing caffeine? I mean, how disruptive is it for sleep?
- MWMatthew Walker
So the profile that you describe, which is high peak early on, first thing when you wake up, and then tapering off nicely down into the sort of early afternoon-
- AHAndrew Huberman
Mm-hmm.
- MWMatthew Walker
... ideal. That sounds great to me. As for that afternoon coffee, it really depends again on when you're expecting to go to sleep. Now, for someone like you, I would say I would love to look at abstaining from that or just switching it out to, if you're using, you know, these pods or however you're brewing it, let's just switch it out and do an experiment for two weeks, and we will look to see how much is that afternoon coffee really impacting your sleep? And we'll track your sleep with some degree of high fidelity with a, a wearable, and let's test that hypothesis. Because you go to sleep quite early, you are an early bird, m- maybe bordering on an extreme, um, early bird, and we'll speak we about, um, or we have spoken about, those different flavors of chronotype, I would prefer you not to be having that caffeine in the afternoon based on how early you go to sleep. And I mention that preference because of what you described regarding your sleep maintenance insomnia. One of the issues with caffeine is that not only can it make it more difficult for you to fall asleep, which you don't have in part because if you're waking up quite frequently throughout the night and struggling to get back to sleep, you're going to be carrying a sleep debt into every night, and that debt continues to grow, and it's almost like compounding interest on a loan. So you will not have a problem falling asleep. In fact, sometimes the speed with which people fall asleep in some of these s- uh, sleep trackers will almost penalize you for falling asleep too quickly is because in sleep science, in clinical sleep medicine, if you're f- it should take you somewhere, you know, healthy sleep onset, you know, 5 to 15, 20 minutes, but if you put your head on the pillow and you turn off the light and within a minute or so you're dead to the world and you're gone, I'm, exactly, I'm worried that you're, A, carrying a sleep debt. Now, not necessarily, but I'm, I would like to explore it, um, with you, and then I would say even if you can fall asleep, fine, this factor of waking up in the middle of the night is also related to caffeine. Why? Because caffeine not only can make it harder to fall asleep, not your problem, but it keeps you out of that deep, deep sleep and it puts you into a more shallow state of non-rapid eye movement sleep. And when you are in the shallow state, it's, A, easier for you to be woken up-But, B, and I think more of the problem, it's harder for you to fall back asleep because your brain doesn't necessarily want to go back down into that deep sleep and nor has it come up out of that deep sleep, so you're not in that wonderful, glorious, thick treacly sort of sleepy state when you wake up, you go to the restroom, you come back and you just know, ah, this is going to be great. I'm, as- as long as I can fumble my way back to my mattress, I'm going to be asleep within another two minutes going back to it. Whereas for you, you probably wake up and you feel pretty wide awake. I would like to see what happens when we negate that afternoon coffee on the frequency and the duration of those middle of the night awakenings for you.
- AHAndrew Huberman
Mm-hmm. Yeah, I'm definitely making the effort to avoid caffeine intake in the afternoon, and I think I'm already starting to see some of the positive benefits of doing that.
- 55:52 – 1:01:19
Caffeine Metabolism & Sleep, Individual Variation
- AHAndrew Huberman
I believe you've, um, give out the numbers, uh, on a different podcast previously. C- talk a little bit about the metabolism of caffeine and, um, and maybe even some of the variations that exist between people in terms of the me- metabolic, uh, regulation of caffeine. So how long, let's say, uh, drink a standard cup of coffee or cup of espresso and it has a, gosh, I don't know, 150 milligrams of caffeine. Is that, uh, 200?
- MWMatthew Walker
Yeah, could be-
- AHAndrew Huberman
200?
- MWMatthew Walker
... 150, 200.
- AHAndrew Huberman
Yeah, let's say 200-
- MWMatthew Walker
Yep.
- AHAndrew Huberman
... because, uh, certainly, uh, you know, a barista these days is going to draw a, a beverage as-
- MWMatthew Walker
They're gonna over-index. (laughs)
- AHAndrew Huberman
Yeah. So, let's say 200 milligrams and, and somebody consumes that after lunch at, uh, 1:00 PM and their bedtime is, let's, let's make them more conventional than I, uh, somewhere between 10:00 and 11:00 PM.
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
Okay, so they're, they're about 10-
- MWMatthew Walker
Nine to 10 hours.
- AHAndrew Huberman
... nine to 10 hours out from their bedtime. They're having a nice, strong, quote unquote, "nice, strong cup of coffee" after lunch. Um, what, what does that look like in terms of their, uh, biochemistry and, and impact on sleep?
- MWMatthew Walker
So, caffeine has something that we call a half-life of about five to six hours, meaning that after five to six hours, about 50% of that caffeine is still circulating in your bloodstream and thus your brain. That means that caffeine has a quarter life of somewhere between 10 to 12 hours. Now this is on average, and we'll come back to variations. But think of it this way, if you're taking a cup of coffee, like you described there, at midday, and then you're going to bed at, let's say 11:00 or midnight, that would be the equivalent based on what I've just told you, the quarter life of getting yourself into bed, and just before you took yourself into bed, you swig a quarter of a cup of coffee and you hope for a good night of sleep and the chances are that it may not happen. Now again, that's a little bit sort of hyperbolic as a, as a statement, but just try to conceptualize it in that way. You would never think about taking on, you know, a, a last quarter cup of coffee just before you put your eye mask on. But-
- AHAndrew Huberman
No, but I have some friends and, um, somebody actually who works with the podcast team and we'll go out to dinner as a team when we're on the road and he'll order, you know, big coffee right after a 9:00 PM dinner. And I was like, "Can you sleep on this?" Oh yeah, no problem.
- MWMatthew Walker
And that no problem is in part this I don't have an issue with falling asleep, but if we were to, based on the data, map their electrical brain activity, you would be able to see this reduction in the deep non-REM sleep. And it can reduce it, if you look at the data, somewhere between 15 to 20%. Now for me to reduce your deep sleep by 15 to 20%, I would probably have to age you by about 20 to 22 years. Or you could just do it every night with a late night coffee should you, should you wish. So again, I've... or and maybe we'll speak about this in, in later episodes. I have changed my mind on caffeine. I think morning caffeine use or coffee, I should say, being more specific, is fine because I think there are health benefits and we can go into in subsequent episodes why coffee and the coffee bean itself can provide those benefits. So I've become a little bit more bullish on morning caffeine. But evening caffeine, I just think it's, the data is just not supportive. Even if you are, and there are variations and you were very, um, astute in your question, some people, I said on average, caffeine has a half-life of about five to six hours. For some people it's quicker and for other people it's slower. Why is that? It's based on a gene, and we know the gene. It's a gene that is part of a set of liver enzymes and the gene is called the CYP1A2 gene, and there are variations in that gene, what we call polymorphisms, and you can do these genetic tests that you can buy, these kits, and they will probably tell you which you are. Are you sensitive? Are you not sensitive? You probably already know. (laughs) And so some people will not be as sensitive and, therefore, they can have a more compressed timeframe of a half-life because it's moving out of the system in a quicker manner. So, again, I'm not trying to be scaremongering. I think you can have coffee in the morning and you'll be just fine. That late night coffee, I would, I would like to see you obviate that if you're someone who's doing it.
- AHAndrew Huberman
And the afternoon coffee sounds like a, you know, maybe only every once in a while and try and make it mostly decaf or decaf for that matter, if it's really just for the taste.
- MWMatthew Walker
Yeah. If it's just for the taste, go decaf. If it's not, I understand that in some ways what I'm talking about is the ideal world, and drum roll, it turns out that most of us don't live in that. We live in this thing called the real world. (laughs)
- AHAndrew Huberman
Mm-hmm.
- MWMatthew Walker
And so if you are facing a circumstance where if you're under pressure at work or if you're high performing athlete and this is it, this is the event, this is you've... it's all or nothing, understand that you might...... you are going to sacrifice some sleep at night, but maybe that sacrifice is well worth it. So again, I'm very open-minded, I'm not trying to be, um, simply, eh, you know, too rigid with this.
- 1:01:19 – 1:02:04
Sponsor: InsideTracker
- AHAndrew Huberman
I want to take a brief break and acknowledge our sponsor, InsideTracker. InsideTracker is a personalized nutrition platform that analyzes data from your blood and DNA to help you better understand your body and help you reach your health goals. Now, I've long been a believer in getting regular blood work done, for the simple reason that many of the factors that impact your immediate and long-term health can only be analyzed from a quality blood test. The problem with a lot of blood tests out there, however, is that you get information back about metabolic factors, hormones, et cetera, but you don't know what to do with that information. With InsideTracker, they make it very easy to understand your results and they also point you to specific directives that you can follow in the realm of nutrition, exercise, supplementation, even prescription drugs that can help bring the levels back into the ranges that are optimal for you. InsideTracker also offers InsideTracker
- 1:02:04 – 1:12:03
Cannabis: THC vs. CBD, REM Sleep, Withdrawal
- AHAndrew Huberman
Pro, which enables coaches and health professionals to provide premium and personalized services by leveraging InsideTracker's analysis and recommendations with their clients. If you'd like to try InsideTracker, you can go to insidetracker.com/huberman to get 20% off any of InsideTracker's plans. Again, that's insidetracker.com/huberman. So you've talked about alcohol and its effects on sleep, you've talked about caffeine and its effects on sleep, and we talked about food and its effects on sleep. What about THC and CBD?
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
Uh, sometimes referred to more, uh, generally as cannabis. And, you know, it's interesting, you know, gosh, when I was growing up, um, you know, cannabis was illegal. Um, nowadays it's, um, either legal or tolerated or decriminalized in many places, not all.
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
But I, I would say there's been a, um, uh, a tide shift in terms of, um, cannabis, meaning that many people consume cannabis who are, um, consuming it legally, and consume it for a lot of reasons that other people consume alcohol in, you know, a sedative effect, a slight hypnotic effect. I mean, you know, the, the actual definition of what these drugs do i- it goes by certain terms in the psychiatric literature of course, but, but in order to, quote unquote, "mellow out," to feel more relaxed, to reduce their anxiety.
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
Um, it's, it's far and away different than when I was growing up where, I mean, you would get into a lot of trouble, uh...
- MWMatthew Walker
Oh, yeah.
- AHAndrew Huberman
... if you were caught, um, smoking a joint or, um, taking a bong rip in the middle of the day, but not... And I realize most people aren't doing that at work, I guess it depends on where you work.
- MWMatthew Walker
(laughs) .
- AHAndrew Huberman
Um, but it, you know, edibles, tinctures.
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
I mean, the, the consumption of THC and CBD is, is quite, um, quite robust-
- MWMatthew Walker
It's non-trivial. (laughs) .
- AHAndrew Huberman
... in a lot of places. So, um, with all the issues of legality and the fact that people who... young people, um, should not be consuming them, meaning people 18 and younger, not just for legal reasons but the brain is still developing, um, what is the story with THC, CBD, cannabis, edible, smoked, uh, tinctures on sleep specifically?
- MWMatthew Walker
It's very interesting if you look firstly at the motivational reasons why people use cannabis. Based on the published study, somewhere in the top two reasons, sleep.
- AHAndrew Huberman
Mm-hmm. To fall and stay asleep.
- MWMatthew Walker
To fall asleep and stay asleep. Obviously, usually the principal first reason is just to get high and have the experience and the pleasure of being high, if that's what sort of floats your, um-
- AHAndrew Huberman
Pleasure.
- MWMatthew Walker
... floats your train, floats your train. But certainly it's, you know, sleep, um, as a... and what we call a hypnotic to put you asleep from, um, the Greek derivative of the god for, for sleep. That is high among the reasons that people will use. We currently don't recommend it and here is why. Certainly THC helps you fall asleep faster, very clear in the data. The problem is that first you start to develop a tolerance and to get that same sleep onset benefit, you need to get... use, I should say, a higher dose, so you start to develop dependency and your dose regiment starts to increase. The second issue with THC is that it's very good at blocking your dream sleep, your REM sleep. In fact, many people when they come and they tell me, "Look, I was a heavy cannabis user or even a light cannabis user for some time, and then I stopped using. And one of the strangest things happened to me, I just started to have the most wild, vivid, crazy dreams and I didn't know what was going on." And it's a very simple explanation. As you've been using, your brain has been compromised in the amount of REM sleep it's been getting and you've been building up chronically a REM sleep debt. And your brain is smart in the sense that it does try to clock, s- to some degree, a counter of how much REM sleep you've lost. And many people will say, "Yeah, I don't really remember my dreams when I'm using." But when they stop, the brain finally, because it's been cleansed of the thing that's the roadblock to REM sleep, not only do they go back to having the normal amount of REM sleep that people would have, they have that plus they have what we call a REM sleep rebound, which is even more a more intense REM sleep which leads to more intense dreaming. So it's a very... I suspect there's a lot of people who've had that experience listening if they have been users and they've stopped. So that's the second reason we don't advocate it. The third reason is that when you stop using you also go or go through a very vicious insomnia withdrawal syndrome, often many people will do. Now that depends on, you know, how much you've been using, for how long you've been using.If you look at the data, and by the way, part of the, um, clinical, the diagnostic, the psychiatric diagnostic, um, description of cannabis withdrawal is insomnia. That's how reliable this insomnia problem is when you come off cannabis. And if you look at the data, the one of the main reasons that people relapse and start using cannabis again even though they don't want to, is because they can't deal with the insomnia that withdrawal has given them. So you don't want to get into that vicious cycle, should you wish. Again, it's your choice. (laughs) Um, so THC I think is not to be advised right now. CBD is interesting. I don't think there's enough data yet for us to have a very strong opinion, but I can at least offer mine. The data so far is a little bit mixed in what we call the effect size. In other words, how reliable and how powerful is the benefit of CBD on sleep? But it does seem to have some benefit. What's interesting is that it doesn't seem to have the detriments that I just described for THC. You've got to be looking at the data a little bit careful with CBD. It has what's called a U-shaped function to it, which is that if you're taking too little, and again, I really, I'm so mindful of not trying to be, "Okay, here are the numbers." But if you look at them, I would say, you know, kind of cross your eyes, squint your eyes, maybe less than 25 milligrams, you run into the danger of CBD being wake promoting rather than sleep promoting. W- once you get past, if you look ish 50 milligrams and above, then you start to go in the opposite direction where it seems to be sleep promoting. And I mention that just because at least here in the United States and in many places in the world, that industry is not regulated. So it may say 50 milligrams on the bottle. You don't really know. Now some of those companies will have what's called third party laboratory testing where they'll send it out and you can scan a QRI code and you can look at an independent laboratory that tested it and show you the pur- pur- uh, purity of it. So that may be one way to go. So CBD I think has some favorable evidence right now. If that's the case, let's just assume that you and I speak in another five years time and there's really good data now for this, what could be the mechanisms? I think there's at least, there's probably at least two, maybe three mechanisms. The first is an indirect mechanism. CBD has been demonstrated very nicely in some fantastic studies to be an anxiolytic, which is a fancy term for saying it reduces down your anxiety. And earlier you and I discussed that anxiety and stress is one of the things that will keep you awake, so indirectly, it removes this kind of gate that is preventing you from moving down the royal road of sleep, and it opens back up the gate because it's removed that gate mechanism which is high anxiety, and by way of being an anxiolytic, it softened that anxiety and it's easier for you to fall asleep. I think that's probably the principle mechanistic bet I would have right now. Another indirect mechanism, if you look at some of the studies in rats, and we do w- um, human work at my sleep center, so w- we don't do animal studies, but if you look at the data in the rats, CBD can be hypothermic, which means that it drops your core body temperature. And just as we spoke about in, earlier in this episode, you need to drop your body temperature to get to sleep. So I think that's the second reason. I think the third reason is that it could have a direct sleep promoting mechanism. I think it's unclear right now exactly how it's interacting with the sleep machinery of the brain. We've got some hypotheses. The danger is, again, it's just not a well regulated substance. So I am actually just, um, full disclosure, I'm working with a company in the United Kingdom, uh, in collaboration with, um, King's College and the Institute of Psychiatry there to see if we can create an analog, a clean analog of CBD, but I think the potential upside of it, not just for sleep, but for a number of different psychiatric conditions like anxiety, um, could be beneficial. So I would say that that's right now the- the sort of the skinny on THC and- and CBD.
- 1:12:03 – 1:16:08
Sleep Hygiene Basics
- MWMatthew Walker
- AHAndrew Huberman
Okay, so just to make sure that I have the basic list of sleep hygiene factors correct, I have regularity is king.
- MWMatthew Walker
Yep.
- AHAndrew Huberman
Light and dark, meaning that one should optimize or at least seek to optimize their exposure to light in the morning and throughout the day and then in the evening to make things dim and dark.
- MWMatthew Walker
Yes.
- AHAndrew Huberman
Temperature, and there you have a- a little, um, it's not a mantra, but what is it? It's a warm up to cool down to fall asleep, and then it's stay cool-
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
... like Fonzie, stay cool to stay asleep.
- MWMatthew Walker
Yep.
- AHAndrew Huberman
And then warm up to wake up.
- MWMatthew Walker
Yep. And we will come onto that I think in a little while again.
- AHAndrew Huberman
Then there's walk it out, which is, if I understand correctly, if you're trying to fall asleep or fall back asleep, and it's taking you longer than about 20, 25 minutes, you should just get out of bed and go elsewhere in the house, do something else, maybe even lie down on a different surface in the house-
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
... to try and see if you can sleep there, but don't stay in bed. Don't create a paired association of wakefulness and your bed because that can lead to problems in subsequent nights.
- MWMatthew Walker
Yeah, and I would only say that-... try to resist if you can. If you really want your bedroom to be the place where you now become consistently asleep, try not to start sleeping in some other location consistently because then all of a sudden you bond that with good sleep and you unbuckle this notion that we're trying to relearn which is, no, your bedroom is the place of sleep. So it's fine to go elsewhere. Try to stay awake and force yourself to stay awake until you are absolutely sleepy, then go back to bed.
- AHAndrew Huberman
Okay, and then we discussed alcohol, food, caffeine, and THC/CBD, AKA cannabis, and with respect to alcohol, it's clear that none is best. If you're going to have some, uh, you don't want to drink too early in the day but you don't want to drink too much-
- MWMatthew Walker
(laughs)
- AHAndrew Huberman
... or too close to bedtime 'cause it can disrupt rapid eye movement sleep. Food, uh, it seems that creating some sort of buffer between the, uh, your last bite of food and, uh, your to bedtime by, anyway, somewhere between, you know, maybe two, three hours, but for some people it'll be more like 90 minutes, and of course that's going to depend on the size of the meal, et cetera. But, uh, eating a big meal and then going straight to bed, probably not a good idea. Caffeine has this long half-life so if you're going to indulge, which I do, do so early in the day. Beware the afternoon caffeine.
- MWMatthew Walker
Yeah, do the-
- AHAndrew Huberman
Yeah.
- MWMatthew Walker
... Huberman Taper is what I'm gonna call it right now-
- AHAndrew Huberman
All right.
- MWMatthew Walker
... which is not an interpretive dance. It's simply-
- AHAndrew Huberman
There you go.
- MWMatthew Walker
... the Caffeine Taper.
- AHAndrew Huberman
And then, um, THC, CBD, uh, does nothing good for your sleep architecture, although some people have the, uh, impression that it is good for their sleep because it makes it easier for them to fall asleep but what they are unaware of is that it is disrupting the quality and architecture of the different stages of sleep in ways that are not serving people well.
- MWMatthew Walker
That seems to be the case for THC, and I think CBD, you know, uh, has promise and research must try harder, including my own. (laughs)
- AHAndrew Huberman
And you, um, very, uh, kindly emphasized that you're not telling people what to do, they just should know what they're doing so that they can make, uh, changes, uh, if they so choose.
- MWMatthew Walker
That's right. I would always say that, um, I'm not trained to be a medical doctor. Any advice that I give is simply scientifically descriptive advice. It's not medically prescriptive, nor lifestyle prescriptive advice.
- AHAndrew Huberman
I'm smiling 'cause what I always say is, um, "I'm a scientist, not a physician, so I don't prescribe anything but I profess lots of things."
- 1:16:08 – 1:20:23
Tool: Poor Sleep Compensation, “Do Nothing”
- AHAndrew Huberman
- MWMatthew Walker
So I think many people may have heard of some of the conventional, but what about the unconventional? I would probably offer f- five or six. The first one I would say is that if you are struggling with sleep and you have had a bad night of sleep, the first recommendation is do nothing. And what I mean by that is, if you've had a bad night of sleep, you were awake for three hours, do not sleep in any later into the morning. Do not go to bed any earlier. Do not increase your caffeine intake to try to offset it, and do not nap during the day. Why am I telling you those things? If you wake up later that following morning, your adenosine clock that we spoke about, this building up of sleepiness that happens when we wake up, is going to start later in the day, so when it comes time for you to fall asleep at what would then be the next night at your normal time, you're not going to feel as sleepy. Why? Because you woke up that much later and you're setting yourself up for failure again. Equally, don't go to bed any earlier. If you have become accustomed and your brain has and your circadian clock has become accustomed to going to bed at a certain time and hopefully you're doing it regularly, then getting into bed two or three hours early has the danger, it's not a certainty but a danger, of you then getting into bed and thinking, "Well, I'm, I know I had a bad night of sleep last night, but I still can't fall asleep straightaway," so now you're spending another 90 minutes in bed at the beginning 'cause you've gone to bed 90 minutes earlier thinking it's a good idea to compensate. Don't do that either. Hold out even if you do feel tired. My recommendation would be after that bad night of sleep, hold out for as long as you can as close to your natural bedtime as possible, then go to sleep and you will give yourself highest chance of success. Don't over-caffeinate. That's the obvious one. Follow the beautiful Huberman Taper. And then obviously try not to compensate with a nap. Why? Because that nap, as happens when we sleep, is going to remove some of that sleepiness, that adenosine, and once again you get into bed and you're not as sleepy as you would naturally be so you again go through a bad night 'cause you're struggling to sleep, or you wake up and you can't get back because you've got less weight of sleepiness on your shoulders due to the nap that happened earlier. So I know it's hard, but I would say when the alarm goes off after a bad night, you just think, "I do not want to get up. It's been such a rough night." I know it's a short-term gain, but trust me, it's a long-term loss because you're going to then just get into this vicious cycle. So that's the first unconventional tip.
- AHAndrew Huberman
The... Can I just pause you for a second? I- I'm a little wide-eyed over here because, um, I did not know any of that. Typically if I get a poor night's sleep I'll do whatever I can to recover that sleep. Uh-
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
... take a nap, I'll d- you know, I'll adjust my s- to bedtime the next evening, um, so I hope...... everyone is paying, uh, careful attention to what Matt just said. I mean, the, that's a important list, because I think one of the very common things is for people to just not get a great night's sleep, and I think most people think, "Okay, I'll drink a little more caffeine, I will, um, go to bed a little earlier tonight, you know, maybe catch a, a nap in the afternoon," this kind of thing.
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
Um-
- MWMatthew Walker
And I would have thought that too and maybe even suggested that, and if you listen to the first episode and where we, you know, I list (laughs) in a doomsday manner the things that can happen by way of a short night, you, you would think that that's what I would then recommend. But it was really imprinted on me by, um, a wonderful sleep clinician, uh, Michael Perlis, um, who sort of described some of these features and exactly the reasons sort of underlying them, and I think I've just tried to bake that out into a, a formula that makes sense. Again, it's not about the rule, it's about explaining it. Because when you explain it, at first it sounds contradictory and paradoxical. When you understand it, it hopefully sounds logical and actionable. Um, so that would be the first suggestion that-
- 1:20:23 – 1:24:11
Tool: Sleep Deprivation & Exercise
- AHAndrew Huberman
C- could I just-
- MWMatthew Walker
Yeah, please.
- AHAndrew Huberman
Sorry to interrupt again.
- MWMatthew Walker
No, please. Please.
- AHAndrew Huberman
My audience hates when I interrupt, but I'm doing it on their behalf, because I-
- MWMatthew Walker
Oh, I love it. It's-
- AHAndrew Huberman
... because, because I, I like to think that there's, um, some value in some of, uh, uh, at least what you say in response. Um, I saw a really, uh, terrific post from Dr. Rhonda Patrick, um, who we both-
- MWMatthew Walker
Oh, she's great.
- AHAndrew Huberman
... know and admire, um, for her public education wor- public health education work. And she described a study whereby if people are, I think it was slightly sleep-deprived, maybe by a few hours, that some of the, uh, disruption to morning blood glucose regulation that is known to accompany partial sleep deprivation, and certainly complete sleep deprivation, but, um, in this case, partial sleep deprivation, could be offset by still exercising in the morning.
- MWMatthew Walker
That's right.
- AHAndrew Huberman
Um, which, frankly, I have to say if I haven't slept that well, then, you know, normally I'm like, "Oh, maybe today's the day I don't exercise." But now having heard that information, I make it a point to still exercise, um, sometimes a l- with a little bit less intensity-
- MWMatthew Walker
Yup.
- AHAndrew Huberman
... um, because I don't want to be completely exhausted in the afternoon, um, e- and, and go to sleep at, you know, 4:00 PM or something, really disrupt my schedule. But I thought that was pr- really interesting-
- MWMatthew Walker
It is, and it's-
- AHAndrew Huberman
... because it's, it's a, it's a sort of, um, partial inoculation of the, of the blood glucose disruption caused by, uh, sleep deprivation.
- MWMatthew Walker
I, I'm so glad you brought it up. It's a fantastic study and I, um, Rhonda and I, um, uh, I think even tried to discuss it some years ago on a show, but I like it because it does offer some degree of actionable hope and a strategy. Blood sugar, absolutely critical. It is very sensitive to sleep. When you don't get enough, it goes in bad directions. You used a very specific word cleverly so, and that word was partially. At first, you hear or read that study, and, and Rhonda was never suggesting this to you, I'm not s- saying that, you think, "Well, if it offsets blood sugar," and the study was saying exercise can nullify a lack of sleep, you conflate that single outcome benefit with the idea that, well, but maybe it doesn't actually re- or doesn't compensate for the deficits in immune function or cardiovascular disease concerns, or my hormonal health, or my learning and memory, or my emotional and brain health. Maybe it does, but maybe it doesn't. So I think I would always just caution people to saying when you hear a study like that, it's very natural to think, "Oh, that must mean that it translates to everything else in my body and everything else in my brain." It may, but it also may not be.
- AHAndrew Huberman
Terrific. So if you don't sleep that well, do your best to still get some exercise, but-
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
... just be mindful of the, um, the fact that, you know, in the winter months especially, that might, if you go too hard in the gym or on a run, you might be a, uh, little bit, uh, immune-compromised. Just be mindful of the fact that you're, you're a more vulnerable being when you're sleep-deprived and that, but that exercise can help adjust things in the right direction. And, and if it's early in the day, um, presumably that's not going to disrupt your, the, the proper bedtime, and if it's later in the day, I suppose as long as you don't need caffeine in order to, uh, to do that exercise and/or, um, if you're familiar with exercising later in the day, fine. I, you know, I find if I exercise, like, I'm not one of these people that can go for a run at, you know, seven o'clock at night and then just shower-
- MWMatthew Walker
Well, that's because you're a morning type.
- AHAndrew Huberman
... and go to sleep. 'Cause I'm a morning type.
- MWMatthew Walker
Correct.
- AHAndrew Huberman
Other people can.
- MWMatthew Walker
Yeah.
- AHAndrew Huberman
Okay, we'll, we'll get into exercise a bit more in a later episode.
- MWMatthew Walker
We should do.
- AHAndrew Huberman
Um-
- MWMatthew Walker
Yep, but-
- AHAndrew Huberman
We'll be sure to do that, but nonetheless, uh, I just raised that now.
- 1:24:11 – 1:32:58
Insomnia Intervention & Bedtime Rescheduling, Sleep Confidence
- AHAndrew Huberman
Um, so what are some of the other unconventional protocols for sleep?
- MWMatthew Walker
So I think other suggestions I would have after do nothing would be try to think about limiting your time in bed. If you are struggling with sleep, this is something that is used in the probably the most well-validated psychological intervention for insomnia, and it's called cognitive behavioral therapy for insomnia, or CBT-I for short. What happens is that you work with a clinician, they interview you, they assess all of the reasons that you may not be sleeping, and then they create from their toolbox of many different options a bespoke, tailored sort of Savile Row soup prescription for you for your treatment. If you look at the studies of that collection of different tools in the CBT-I box for intervention of insomnia, and you ask, "Of all of those, which seems to carry the greatest impact on insomnia? Which has the greatest sort of gravitas?" it seems to be this thing that we call bedtime rescheduling. It used to be known as sleep restriction therapy, but obviously if you come to me and you say, "Look, I am not sleeping very well. I've got insomnia," I say, "I understand, and I've got a treatment for you. It's called sleep restriction therapy." And you say, "No, no, no. You didn't understand. I, I'm not getting enough sleep." (laughs) ... but it's not quite that. Here's how it works. If you are spending so much time in bed, too much time in bed, you are not forcing your brain to be efficient. And by way of constraining your sleep window, even to, let's say, five hours a night to begin with, I brute force ruthless efficiency from your sleeping brain after several days. So another analogy would be, let's say you're trying to make a nice thin crust of, of pizza base and you put the dough on the table and you start rolling it out. If you roll it too thin, it starts to get gaps and holes in it. Why? Because you've spread it out too far and you've started to create these absences. That's the same thing that happens and it's very natural. As an insomnia patient, you would say, "I'm just not getting enough sleep so I'm going to start spending more time in bed." It's the very worst idea. Another way would be to say, "Look, I go to the gym and I, you know, spend about an hour and a half working out." But if I were to videotape you, a lot of people are doing the... I think you've... I, I've coined it as your phrase, but, um, the eleventh rep, where people, you know-
Episode duration: 2:42:54
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