Andrew Huberman: The Science of Small Changes

Leading neuroscientist and Stanford University School of Medicine professor Dr. Andrew Huberman goes in-depth on how small behaviors can make a huge impact on your health. Dr. Huberman offers essential insights into how light affects your sleep and your energy levels, which supplements actually work, tips to control bad impulses, exercises to slow the aging process, and so much more. Dr. Huberman has made numerous significant contributions to the fields of brain development, brain function and neural plasticity, which is the ability of our nervous system to rewire and learn new behaviors, skills and cognitive functioning. Huberman is a McKnight Foundation and Pew Foundation Fellow and was awarded the Cogan Award in 2017, given to the scientist making the most significant discoveries in the study of vision. His lab’s most recent work focuses on the influence of vision and respiration on human performance and brain states, such as fear and courage. -- Want even more? Members get early access, hand-edited transcripts, member-only episodes, and so much more. Learn more here: https://fs.blog/membership/ Every Sunday our Brain Food newsletter shares timeless insights and ideas that you can use at work and home. Add it to your inbox: https://fs.blog/newsletter/ Follow Shane on Twitter at: https://twitter.com/ShaneAParrish Learn more about your ad choices. Visit megaphone.fm/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Speaker 00

  And if you're somebody who's really into self optimization and you're doing a lot of work on yourself, maybe you've been doing some therapy or journaling or work on traumas and you're optimizing your hormones and sleep, you are in a very small category, unfortunately, of people that's really trying to be healthy for yourself and for others. After age 25, the brain doesn't change unless it's self-directed change. So don't expect anybody to change unless it's self-directed. Forget trying to get people to change. It does not work. It works with children. It does not work with adults unless it's self-directed plasticity. And there is tons of literature to support that statement.

• 0:52Shane Parrish?

  Welcome to the Knowledge Project Podcast. I'm your host, Shane Parrish. The goal of this show is to master the best what other people have already figured out so you can unlock your potential. To that end, I sit down with people at the top of their game to uncover what they've learned along the way. Every episode is packed with timeless ideas and insights that you can use in life and business. If you're listening to this, you're missing out. If you'd like special member-only episodes, access before anyone else, transcripts, and other member-only content, you can join at fs.blog/membership. Check out the show notes for a link. Andrew Huberman is here today. Andrew is a neuroscientist and tenured professor in the Department of Neurobiology at the Stanford University of Medicine. I wanted

• 1:37Shane Parrish?

  to talk to Andrew for a long time to get a better picture of the small behaviors we can put to work for us that make a big impact when it comes to our health. And with such a big area to cover, where to begin is always hard. We start with light. How light not only impacts the way we feel and learn, but how it impacts our sleep. We go on to explore the difference between falling asleep and staying asleep, over the counter pharmacological supplements, the relationship between vision and breathing. But we don't stop there. We also cover how the source of most of our problems is impulse control. So we explore how to subordinate those impulses. We also explore sleep mattresses like Eight Sleep and exercise to reverse the aging process. As regular listeners know,

• 2:19Shane Parrish?

  I tend to explore subjects through the lens of my guests and often, as is the case here, we explore similar ground through new eyes. Consider sleep, something we talked about with Matt Walker, we cover here with Andrew, and we talk about in an upcoming episode with David Sinclair. We cover the same subject with three people in detail through different lenses to get a better sense of what works and what doesn't. And before we dive in, the lawyers want me to point out that the science-based insights in this podcast are not medical advice. They also tell me that you should get advice of your doctor before you do practically anything. It's time to listen and learn.

• 3:05Shane Parrish?

  Let's start with light. Light seems to impact the way we feel, how we learn, and how we sleep. How does light exposure or sunlight exposure impact the way we sleep? During the day, we have the opportunity to interact with light in various ways, and our cells use that information. But maybe you can take us through how we can use light to get a better night of sleep.

• 3:24Speaker 00

  Sure. So, light is perhaps the most powerful stimulus for our mental, physical health and for our performance in every endeavor. We often miss this point because the effects of light are what we call slow and integrative. You know, if you look at a particular color of light, it's not that suddenly you're going to be endowed with superpowers. If you don't view light at For half a day or for a day, you're okay. But what light does is it sets the foundation of our abilities and it does that indirectly, indirectly. It does it indirectly by controlling when we are asleep and when we are alert. And it also has direct effects on the way that our nervous system functions.

• 4:09Speaker 00

  So I'll just get right into some practices and then I'll flesh out those practices with some science to explain why they work rather than dropping a lot of scientific nomenclature and then telling people what was is useful. The way that we function is by way of our nervous system. Our nervous system links all the organs of the brain and body, brain, spinal cord, but then of course spleen, heart, lungs, et cetera. And the nervous system is the system that coordinates all of those. The nervous system therefore is without question the most powerful organ system of our body and it acts as a conductor. It is locked inside of our skull and body and it has no knowledge of the outside world.

• 4:50Speaker 00

  And vision, which involves photons, light energy, reaching the eyes, getting converted into electrical signals, is the way that the nervous system decides when to be alert and functional and when to be asleep. And it also is what determines all the various little oscillations in ability to focus and creativity and all the other things that we consider life. When you wake up in the morning, your brain and body have effectively been in the dark regardless of what sleep environment you happen to be sleeping in. And you have a set of neurons, nerve cells in the back of your eye and a little structure called the neural retina, it's a little three layered structure.

• 5:31Speaker 00

  And those nerve cells are not involved in detecting the shapes of things. What they are essentially looking for, what activates them is bright light ideally from sunlight. And when bright light, ideally from sunlight, reaches the eye, those particular neurons send a signal off into the vaulted dark of the brain. They do that by way of a little wire called an axon, and they communicate with an area of the brain that's vitally important called the hypothalamus. It sits right above the roof of your mouth, and it harbors a bunch of structures that are responsible for hormones like testosterone and estrogen, for cortisol release in other locations in the body. Basically, it controls when you're going to be alert, when you're going to be asleep,

• 6:16Speaker 00

  your hormones, your immune system function, and your appetite and your mood. So this morning signal of getting bright light in your eyes is absolutely vital. Now, how does one do this? The best and ideal way to do this would be to wake up, go outside, and get some bright light in your eyes without sunglasses. If you have to wear corrective lenses or contacts, that's absolutely fine. Now, the ideal situation would be a nice, bright, clear day. You get five to 10 minutes of sunlight. You don't have to look directly at it. In fact, never look directly at any light of any kind that's so bright that it's painful to look at. But you get some light indirectly through into your eyes, some bright sunlight. You go inside and get ready for your day. By doing that, you do a number of things.

• 7:00Speaker 00

  First of all, every cell in your body has a 24-hour clock, meaning there's a timer that goes from 0 to 24 and then repeats. And that's true from the day you're born until the day you die. However, every cell in your body has its own separate clock, and the way that those clocks are coordinated into coherent action is from a signal from this brain structure called the hypothalamus. And the only way that signal can arrive properly is if you're getting light to trigger the hypothalamus to say, "Okay, it's the start of the day. Everybody start." Otherwise, your body slowly over time becomes a little bit of a clock shop where every clock is on a different timer, and it's alarming at different times. This is actually what happens when you travel and you get stomach issues or you're not feeling right from jet lag.

• 7:43Speaker 00

  Your body clocks are, the individual clocks of the cells in your body are falling out of sync. So you get up in the morning, you go outside, and you get some bright light in your eyes. However, many people, including me, wake up before the sun is out. In fact, I'm up, you know, early this morning, and there's very little light in the sky. The sky is just a pale gray right now. In that case, it's very simple. Flip on as many bright artificial lights as possible, ideally overhead lights, because the neurons in the eye that perceive this light And send that signal to the brain reside in the lower half of the eye and therefore, because of the optics of the eye, they actually view the upper visual field. But sunlight is really the key. And so, once the sun is out, it's very important to get outside and get anywhere from, you

• 8:28Speaker 00

  know, five to 20 minutes of bright light exposure. A lot of people can't afford the time of 20 minutes. If it's a dim, overcast day, the remarkable thing is there is more photon light energy coming through that cloud cover than there is from these bright lights of the sort that are behind me here. Now, some people live in an area of the world where it is very dark in winter, or their schedule is arranged such that they just can't do this within 30 minutes of waking. In that case, there are daylight simulators that are commercially available. They're very expensive. What I recommend is actually something quite low cost and works just as well, which is you get a ring light, like the selfie ring lights that the YouTubers and the Instagrammers

• 9:07Speaker 00

  use, and just put that on a table or facing you as you work in the morning, and actually, you could leave that on all day. Basically, what you want to do is get as much bright light as you safely can in your eyes all day long, and then as little bright light in your eyes as you can between the hours of about 10:00 PM and 4:00 AM, for reasons we can discuss. So, bright light exposure through windows or windshield will not suffice. Those unlike corrective lenses on your eyes, glasses and contacts, don't focus the light to your eyes. In fact, they're designed to filter the very light that triggers activation of these neurons. The key thing is to understand that, people have probably heard that blue light is bad, wear blue blockers. Blue light is wonderful.

• 9:50Speaker 00

  Blue light is actually what sets this clock in the eye, excuse me, the clock in the brain that signals to the rest of the body. It creates a state of alertness and well-being throughout the day, and it sets a timer of about 16 hours for when you're going to get sleepy later that night. And I'll explain the mechanisms in a moment. So throughout the day, you want to get as much bright light in your eyes as you can. If you need to use one of these ring lights, great. Some of them are very low cost. I realize everyone has different budgets. But the daylight simulators are kind of ridiculously expensive, considering that all you really need is a bunch of bright light in your eyes. However, sunlight is best. And so if you have breaks during the day, go outside, even if you're going to be on your phone texting. If you can take calls outside, do it. If you can get out onto a balcony, do it.

• 10:34Speaker 00

  If the sun is on the opposite side of the building and you're on the balcony taking a call, you're still getting more photons, more light energy. And a fun little free resource that's out there, there's an app called Light Meter. And the photographers will know about this. Light Meter, you basically open up this app, you can press it in the direction, you point it, excuse me, in the direction that you're looking and you can press the little button and you'll see, it'll tell you how many lux, how much light energy is coming from that location. It's approximate, but it's pretty good. And you'll notice that on a dim overcast day, you're getting, you know, 8,000 lux of light coming to you. And then you'll point at one of these very bright artificial lights in your home and you'll look at, and it'll say 800 lux. Wow, how is that? Well, it's because there's a lot of light scattering in the outside, so you don't perceive

• 11:19Speaker 00

  it as a focused beam.

• 11:23Speaker 02

  It's me, the

• 11:26Speaker 02

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• 11:38Speaker 02

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• 11:44Speaker 02

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• 11:52Speaker 03

  How about a latte?

• 11:53Speaker 04

  Maybe dark roast?

• 11:54Speaker 03

  Vanilla?

• 11:55Speaker 04

  Caramel?

• 11:55Speaker 03

  Blueberry?

• 11:56Speaker 04

  You could get them to agree on one flavor, or give everyone what they want.

• 12:02Speaker 04

  With Keurig, there's over 500 K-Cup pie varieties of fresh, flavorful coffee. No effort, no grind, no settling.

• 12:13Speaker 04

  Great coffee without the grind. Keurig.

• 12:18Speaker 00

  So this, this behavior, this, this activity should be done every day. If you miss a day, it's okay. There's a slow integrative system, but you don't want to miss more than one day. Why? Well, one of the key features of every cell in our body is that it's coordinated to a general hormonal signal. Hormones are chemicals that are released in one location in the body that go and act at other locations in the body. And a key hormone for health is cortisol. We always hear about cortisol as a stress hormone, but cortisol, every 24 hours, there is going to be a peak in cortisol release. That's non-negotiable. It's a healthy peak. It's the one that wakes you up in the morning, increases your body temperature, which is part of waking up, gives you focus and alertness.

• 13:01Speaker 00

  It activates your immune system in a positive way, provided you don't have too much cortisol throughout the day. And that peak is going to happen no matter what. If you get light in your eyes early in the day, that peak will arrive early in the day. This is vitally important because one of the key findings in the, in the field of psychiatry, biological psychiatry, is that when that peak doesn't arrive early in the day, it starts drifting later and later and later in the day. And people start getting mood issues, they start feeling irritable, and actually, it's a hallmark physiological signature of depression to have a late-shifted cortisol peak. In addition to that, many people who have depression, or even mild depression, wake up at two or three in the morning and can't fall back asleep.

• 13:44Speaker 00

  In fact, that's one of the first things that psychiatrists will ask about if you go into their office. And it doesn't mean that if you're waking up at two or three in the morning that you're necessarily clinically depressed, but it's one of the hallmark features. And many people report that just simply getting bright light exposure in their eyes early in the day, ideally from sunlight, corrects a number of these issues. Will it cure clinical depression? Probably not if it's very severe, but many people actually feel better all day long, they sleep better. Obviously, this is a zero-cost tool. And when I say we were designed to do this, I, I don't get into discussions about design and spirituality. As I always say, one thing is absolutely certain, which was that I was not consulted at the design phase, and neither was anyone else that I know.

• 14:29Speaker 00

  So I can't answer questions about that. But these cells and circuits are there for a purpose. They have no other function except to bring information about when there's light in the environment to the brain. And essentially to convert that into a bunch of hormonal signals. So I want to talk about the other hormonal signal because this is really key. Many people have heard of the hormone melatonin. This is a hormone that is secreted from a little gland, little pea sized gland in the brain called the pineal. The pineal is the only source of melatonin in the brain and body. And melatonin's role is to make us feel sleepy and fall asleep. It does not actually keep us asleep. I'm not a fan of melatonin supplementation for reasons we can talk about in a little bit. But light viewed by the eyes inhibits melatonin.

• 15:15Speaker 00

  So much so that if melatonin levels are at their peak and you walk into the bathroom at night and you flip on the lights and it's really bright. If you spend more than 10 or 15 seconds in that light, your melatonin levels will drop to zero. So this is a remarkable relationship between the external world and melatonin. And this is why in the evening, you don't have to be paranoid about lights. But what I recommend is that starting around, you know, eight, nine PM or 10 PM. Start dimming the lights in your environment. Just dim the lights as low as you can safely have them. People have different lifestyles and different needs. If you're on screens, dim the screens. If you want to buy blue blockers, fine. I don't have any relationship to any blue blocker company.

• 15:54Speaker 00

  The truth is you need to be worried about the brightness of light more so than the color of light. I know people that have converted their entire home to red light at night, which is definitely the wavelength of light that has the least stimulating effect on this system. And that's kind of an interesting thing. I think we're going to start seeing more kind of smart homes and smart lighting systems. But most people don't do that. I don't do that. What I do is in the evening, I start dimming the lights. And if I use lights, I use lights that are set low in the physical environment. And that's because they won't trigger activation of these cells quite as much. You really want to control your transition into wakefulness by viewing bright light early in the day and throughout the day.

• 16:34Speaker 00

  And then you really want to control your transition into sleepiness by dimming the lights in the evening. And if you, if people do those two things, they are going to see an outsized effect on their mental and physical health. It's without question. And then there's one other kind of. Tweak to all this, that's if you can, try and get outside in the evening or late afternoon when the sun is headed towards the horizon. It doesn't have to be a sunset. If you can watch the sunset, great. But what we call low solar angle light has particular wavelengths that are optimal for activation of these cells. And what happens then is very interesting. You're giving it two signals. You're giving it a morning signal saying, ah, it's morning, if you'd like that

• 17:15Speaker 00

  morning. Then you're getting an evening signal and this clock in the brain for the, it gets a little technical, but it has two oscillators and has a morning oscillator and an evening oscillator. And then your system really knows where it is in time. And then if you avoid bright lights in the evening, most days, you know, we've all, you know, fall off every once in a while. You go to a show or you go out and it's bright in the restaurant. Fine. No big deal. But if you do this most days, your system starts to hum along with the natural rhythms of the rise and falling of the sun. And it's no coincidence that we have a 24 hour clock in every one of our cells because the earth, of course, spins on its axis once every 24 hours. And in addition to this, if you start doing it regularly, something really beautiful happens, which is

• 18:00Speaker 00

  that melatonin signal, remember, light inhibits melatonin. The longer the day, the shorter the melatonin signal. So in summer months, your, your body releases very little melatonin. In winter months, because days are shorter and there's less light overall, you release much more melatonin. So you actually have a calendar system in your body that relates to the orbit of the earth around the sun once every 365 days. And what happens is when you start getting regular about morning light viewing and in some sense, evening light viewing every once in a while, or ideally every day, what happens is your system starts to fall into a very regular pattern where you feel sleepy when you expect to and want to be sleepy. You feel wide awake.

• 18:43Speaker 00

  And people actually report the subjective experience of going outside in the morning and as the sun comes out, or as they get this bright light exposure from an artificial light, they can actually feel their system charging. That's not a placebo effect. That's a real effect of the release of cortisol and adrenaline into your body. The release of dopamine is controlled by light, powerful neuromodulator that makes you feel good. So I could go on and on, but it's very simple. Get as much bright light in your eyes, ideally from sunlight throughout the day when you want to be alert. Really limit the brightness of light and the amount of light as you head into the nighttime. If people have shift work or they're raising newborns and things of that sort, there it's a whole other discussion, but what I recommend is,

• 19:27Speaker 00

  I have an episode on jet lag and shift work that gets really technical, but does offer some tools and it just would take us off course here. But I do realize and I want to acknowledge the shift workers and parents that are raising kids that can't adhere to this, but I think most people can.

• 19:41Shane Parrish?

  What's your evening routine, including supplements? From like, take, walk me through 5:00 PM until your, your lights out, falling asleep in bed.

• 19:49Speaker 00

  I generally go to sleep somewhere between 10:00 and 11:00 PM. Although lately I've been going to sleep much earlier because I've been finishing my last meal sometime right around 6:30, 7:00. And that's not because I'm on some extravagant nutritional routine. I've just started getting up earlier for social reasons. My partner, she goes to bed really early. And so just for coordinating schedules, it just, it just makes sense. But I think most people go to bed somewhere between 10:00 and 11:00 PM or you know, 9:00 and 11:00 PM. So, right around 5:00 PM, I'm not an evening exerciser. I like exercising in the morning or the day.

• 20:31Speaker 00

  The way I like to exercise, I like to exercise pretty intensely for about 45 minutes or 50 minutes. And that requires caffeine for me and I don't want to drink caffeine too late in the day. So I stopped drinking caffeine around 2:00 or 3:00 PM and oftentimes earlier. But a couple of things happen in the evening. First of all, my evening meals are more laid in with carbohydrates than they are proteins typically. Not every day. There's times I'll have a steak for dinner or something like that. Chicken soup or whatever it is. But it's very clear that fasting and low carbohydrate meals, I'm not saying diets overall, but meals, that those lend themselves to more alertness and focus. A lot of people say, well, how can that be? The brain uses glycogen, you need carbohydrate.

• 21:14Speaker 00

  Well, when you eat a meal that is slightly devoid or devoid of starches. It creates a sense of alertness because there's actually a mild adrenaline response. So what I do is I basically I'm rewinding a little bit into the earlier part of the day, but I fast until about 11 o'clock. I usually get my exercise at some point before 11 o'clock or noon. I'm not super strict about that. Then my meal is generally something, some meat, a salad, something low carbohydrate. If I train really hard, I might have some rice or oatmeal or something like that and some fruit. And then in the afternoon, I have a snack, which is also pretty low carbohydrate because I want to have that alertness and I'm drinking caffeine. So I'm kind of humming around, doing my work and trying to get into that high focus state.

• 21:55Speaker 00

  For dinner, I generally will eat pasta or something that includes more starches because starches are known to actually reduce cortisol levels in the body. This is why we eat comfort foods. Most comfort foods involve eating foods that are pretty carbohydrate laden because there's a pathway involving carbohydrates and the amino acid tryptophan that converts to serotonin and it essentially blocks the cortisol response. A lot of people that are on very low carbohydrate diets, I have no problem with that if people do ketogenic diets or low carb diets, but those people often have a hard time sleeping. So in the evening, I tend to eat pastas and rice and soups and I still eat some protein, but I, from clean animal sources, because that's what works for me.

• 22:39Speaker 00

  But, but I generally am shifting my whole system towards more quiescence. I might do a little bit of work in the evening. We are not big screen people in the evening. I do read books. Generally, we end up hanging out, just talking and listening to music and things like that. I might do some writing on the computer. So right around eight or nine PM, I start bringing the lights down. In fact, I have a real sensitivity to the overhead lights because I'm so used to this pattern. So I start dimming the lights in the evening overhead. And then for the transition to sleep, I do keep my phone out of the bedroom as much as possible. Sometimes I'll use it as an alarm, but I'll put it on airplane mode. If I'm feeling a little too alert, I remember two things.

• 23:22Speaker 00

  One, the biggest peak in alertness actually occurs about 90 minutes before your natural to sleep time. A lot of people don't know this. This beautiful work from Chuck Zeissler's lab, he's an MD out of Harvard Medical School. And what he discovered in tracking people's wakefulness and activity patterns is that they're buzzing around all day doing things ideally, but then, right before their natural pulse and melatonin takes off, they have this peak in activity. And this, I think, probably hearkens back to some need to, you know, tamp down all the safety leaks that might be in one's environment and, you know, get everything prepped. Because when you're asleep, you're actually pretty vulnerable to predators and attack and things of that sort. That's the rationale, and nobody really knows.

• 24:06Speaker 00

  But you can essentially figure out your best to bedtime by when you have this big peak in activity and then it kind of subsides. So sometimes if I'm feeling a little too alert and wide awake, what I'll do is, I'll just remember that that's going to pass naturally. And people vary, but some people are just really tend to be very forebrain oriented, as I call it, they're thinking and anticipating all the time. It's good to try and taper that off. One of the absolute most powerful tools that has come into my life in the last decade, and that my lab works on, and there are people in psychiatry at Stanford that are also working on, is a practice that I call non-sleep deep rest, which is NSDR. Non-sleep deep rest is an umbrella term that admittedly I created to include things like

• 24:49Speaker 00

  yoga nidra, which is actually doesn't involve any downward dogs or handstands or anything. Yoga nidra is an ancient practice. There are some scripts online, many of them are very good. You go on YouTube, you can find one of these scripts, they're totally cost-free. Put in headphones or put your phone next to you, you lie down, and it's a 10 to 30-minute script that walks you through a progressive relaxation of your nervous system. There's some breathing. What this practice does is it teaches you to deliberately turn off your thinking and to relax your body, and it makes it easier for people to access falling asleep. More easily de-stress. Now, the question is when to do NSDR? You can do NSDR first thing in the morning if you ever wake up and you did not get enough sleep. I often wake up and feel, ah, I didn't get enough sleep.

• 25:34Speaker 00

  I'll do a 30-minute NSDR and I come out of that feeling terrific as if I got a full night's sleep. And I do this almost every day at some point. I might do it in the afternoon. Or if you wake up in the middle of the night and you're having trouble falling back asleep, I highly recommend doing this because even if it doesn't put you back to sleep, it's better than being awake and ruminating and you're teaching yourself to fall back asleep. The other resource that's really wonderful is something called Reverie, R-E-V-E-R-I. Reverie is an app for Android and Apple. It was developed by my colleague David Spiegel in the Department of Psychiatry at Stanford. So an MD, he's a world expert, or I should say the world expert in clinical hypnosis, not stage hypnosis, but self-hypnosis for, um, you'll find a number of things in the app.

• 26:19Speaker 00

  Improving sleep, focus, chronic pain, anxiety. And I should say every one of those scripts and Reverie on the whole has excellent peer-reviewed data, clinical data, scientific data, that we know what brain areas turn on and off as a consequence of doing these things. It's a really powerful tool and these are only 15-minute scripts. Again, the best time to do them is first thing in the morning before you go to sleep at night or any time of day is the kind of joke that I make, which is just get in the habit of doing an SDR or a Reverie script. You don't have to do it every day. You could do it maybe once or three times a week. And what you're doing is you're learning how when you wake up in the middle of the night, you go to the bathroom, you come back, you're like, ah, now my mind is racing. What do I do?

• 27:00Speaker 00

  Instead of getting on your phone, you can start to use some of the progressive relaxation that you learned from those scripts, or you can actually do those scripts. And so I tend to do those in the evening or when I wake up in the morning. And that greatly facilitates my transition to sleep and, and just being a more rested person. Now, in terms of supplements, I'm a big believer that supplements are powerful and are a terrific, often a terrific replacement for prescription drugs. Not that there aren't terrific prescription drugs. I mean, many people benefit from prescription drugs. I take a few. But I think that Many people rely on things that are excessive and habit-forming, expensive and unnecessary.

• 27:43Speaker 00

  But I will say, first off, behavioral tools should form the foundation of all your sleep tools, your wakefulness tools, behaviors first, behaviors first, behaviors first, for one simple but important reason, which is that behaviors rewire your nervous system. They engage what we call neuroplasticity, which is your nervous system's ability to change. You get better at falling asleep when you do NSDR or Reverie. You get better at waking up and feeling alert when you view bright light in the early part of the day. With supplements and things of that sort, your system can react in the moment, but it doesn't rewire, it doesn't get better, such that if you don't take that thing, you're just where you were before. Now that said, there are some supplements that have been tremendously helpful for me

• 28:26Speaker 00

  for sleep over the years, and I know now that there are, humility aside, just from having blabbed about these on various podcasts, including mine, I think there are probably hundreds of thousands of people taking these things. And I want to be very clear that I have no financial relationship to whether or not people take these things or not. My podcast is sponsored by a supplement company, but I'm not even going to mention it. I just think, find the lowest-cost, high-quality source you can. There are many. And so the three things that really can help with the depth and transition to sleep are magnesium threonate, T-H-R-E-O-N-A-T-E, magnesium threonate. An alternative, which is just as good, is magnesium bisglycinate,

• 29:11Speaker 00

  B-I-S-G-L-Y-C-I-N-A-T-E, bisglycinate, either one. And what you're looking for is to get somewhere between 100 and 200mg of those. Sometimes you'll see on the bottle it says 2,000mg, that's the elemental magnesium. It'll also see a smaller number, go with the smaller number. What does this do? Well, it makes people feel a little drowsy and it greatly increases the depth of their deep and the amount of deep sleep. If you're a sleep tracker type with whoops or auras, you'll see this. About 5% of people don't like magnesium threonate and bisglycinate because it gives them stomach upset. You'll know the first time, but most people do just fine. The other thing is a really powerful supplement, which is wonderful,

• 29:54Speaker 00

  is apigenin, A.P.I.G.E.N.I.N. Apigenin is a derivative of chamomile. And I should say that 50 milligrams is the target there. And there's only one source that I know of. I have no relationship to them, but that's Swanson, and these things are available online. I take bisglycinate and apigenin. And you take them about 30 to 60 minutes before sleep, and most people report having incredibly improved sleep. Are they habit forming? Not that I am aware of. Should you check with your doctor? If yes, if you have, especially if you have a heart condition, taking magnesium because of the way neurons work, you, it's an electrolyte, and you might want to check for that purpose. But most physicians, I

• 30:37Speaker 00

  think, would put these well within the margins of safety. But check with yours. Now, there's a third supplement, which is theanine, T.H.E.A.N.I.N.E. Theanine's an interesting one. Theanine, magnesium threonate, and apigenin all trigger the activation of a neuro hormone, excuse me, neurotransmitter in the brain called GABA, which tends to shut off our forebrain. Theanine, anywhere from 100 to 400 milligrams, is a powerful third component of this threonate or bisglycinate, apigenin stack. And theanine is interesting, though. Your dreams will get very vivid. People who have night terrors, or who have

• 31:18Speaker 00

  who sleepwalk, should not take theanine. But theanine is a great addition to this evening supplement stack. And I do that about 30 to 60 minutes before sleep. One last point about sleep, if you wake up in the middle of the night, Turn on as many lights as you need in order to navigate around safely. But again, try and keep the lights low. And waking up once in the middle of the night to use the restroom is perfectly normal. A lot of people think, oh, I woke up. Now my sleep is disrupted, my sleep tracking score, my recovery isn't good. I'm a big fan of sleep trackers, but I don't use one. I go on subjective feelings of wakefulness during the day. Just remember insomnia clinically defined is whether or not you're falling asleep during the day because you're having trouble sleeping at night.

• 32:00Speaker 00

  A lot of people think they have insomnia when what they actually have is anxiety about waking up. And they they're just concerned that they've heard all the terrible things that happen if you don't get enough sleep. Obviously, you don't want to drink so many fluids before sleep that you're waking up all night to use the restroom. One of the nice things about a carbohydrate rich meal in the evening is carbohydrates actually hold water. Anyone on a low carbohydrate diet will notice that they lose a lot of weight. They they think they're leaner, they're actually excreting a lot of water. So that's key. And then the temperature thing is really big. We haven't talked about temperature, but second to light, temperature is the most powerful stimulus for wakefulness. Actually, when you wake up in the morning, it's because your body temperature is rising. So what time do you typically wake up in the morning?

• 32:44Shane Parrish?

  I wake up around five.

• 32:46Speaker 00

  So your, what we would call temperature minimum is 3 a.m. So a temperature minimum is not a specific temperature. It's a time in the 24 hour cycle. And it's about two hours to 90 minutes before your natural waking. I'm not talking about the waking that happens in the middle of the night and you go back to sleep. I'm talking about the wake, the typical wake up time where you would rise. Okay, so for you, your temperature minimum is about 3 a.m. And then your body temperature is going to start increasing, increasing of that cortisol release. If you can get light exposure as that slope is rising, is is increasing, then you're going to augment a faster increase. Okay, if you were to view light or get up at 2 a.m.,

• 33:28Speaker 00

  it would actually jet lag you and it would actually shift you in the opposite direction as if you were waking up in some other location in the world. So that temperature minimum is kind of a nice thing to keep in mind. What happens is your body temperature is going to go up. And then somewhere around three or four in the afternoon, maybe for you, because you're a really early riser, maybe about two or three in the afternoon, it's going to hit a temperature peak. The temperature peak is interesting. The temperature peak. You would think, oh, that's my time of greatest wakefulness. It's actually when you're gonna feel a little bit of a drop in energy in the afternoon. And then it starts dropping, you actually feel pretty good in the evening. And then temperature should continue dropping because in order to fall asleep and stay asleep, you need your body temperature to be about one to three degrees lower than it was in that in the afternoon.

• 34:12Speaker 00

  So one thing you can do is you can keep the temperature in your home a little bit lower at night and just stay under blankets. We actually dump heat mainly through the palms of our hands, the upper half of our face and the bottoms of our feet. There's a special portals between the blood and the skin there. Beautiful name was discovered by my colleague Craig Heller at Stanford. These are called glabrous skin. For the aficionados, you have arteries, capillaries and veins. And in these particular locations, it basically only goes to art from arteries to veins. You skip all the little estuaries that are the capillaries between them. And you're able to basically dump heat more easily. During the middle of the night, the best thing to do is to have warm blankets on top of you and be in a cold room. And then if you get too warm, you will just naturally in your sleep,

• 34:57Speaker 00

  you'll just extend a foot or a hand out. You've probably heard sleep with socks on, terrible idea. I don't know why that caught on. That makes no sense whatsoever. You, you want to be able to dump heat in the middle of the night because if you get too hot, you'll wake up. If you can extend a hand out, that's great because if the room is too hot, what are you gonna do? You're not gonna put your hand into a bucket of ice next to your bed. I mean, most people don't have that device. Some people use these chili pads or eight sleep or these kinds of things. I, I actually don't have one personally. I tend to run kind of warm, so I try and get the temperature.

• 35:30Shane Parrish?

  I use it, that, that's an interesting question. Like I use an eight sleep and it, it can adjust the temperature throughout the night. So how should I adjust that to optimize the quality of my sleep? Should I start from cold and like gradually go warm? Or should I just do cold all night?

• 35:46Speaker 00

  So I would say moderate temperature at the beginning of the night. And for the first two or three hours of sleep, then you. Want to keep it cold until about that three or four AM point. And then, starting right around four forty-five, your body is naturally heating. But if you were to allow it to heat up, then I think you would wake up more quickly.

• 36:05Shane Parrish?

  Yeah, you want to start with like an average temperature and then go colder and then go warmer.

• 36:10Speaker 00

  That's right. You want to mimic what would happen if you were sleeping outdoors, essentially.

• 36:15Shane Parrish?

  Right.

• 36:16Speaker 00

  And, and there's a beautiful study, there was two studies, actually, that were published out of the University of Colorado, where they took students camping for two days. And they made them eliminate all their electronic devices. So they had to rise with the sun and go to sleep or get into their tents at night, more or less when the sun went down. They found that just two days of getting onto that pattern with the rise and fall of the sun, and they were sleeping outdoors, so they had the temperature, whatever temperature what happened to be that time of year in Colorado. They found is that that reset the cortisol and melatonin rhythms for a week, which is incredible. They went back to their normal chaotic pattern of bright lights and college life. And there, and the, the rhythm, because it's a slow oscillator system, stuck for a week.

• 37:00Speaker 00

  Now, that doesn't mean just do these things two days out of the week, but it's really incredible. Um, I've looked at those data a lot and, uh, it's, it's just remarkable how the system will map to this. So I think if you want to have moderate temperature, um, early in the night, then drop it low to bring you to your temperature minimum and then heat, heat up when you want to wake up. You're good to go. Well, I should mention that some people like to heat up in the morning to get more energy. And they'll do that with a cold shower or ice bath. And you might say, wait, that's crazy. You're getting in the cold water. Well, this is a kind of an interesting and counterintuitive one. Your brain has an area called the preoptic area, the hypothalamus, that's more or less like a thermostat.

• 37:41Speaker 00

  So if, let's say you're overheating, you went running, you're overheating and you put some cold icy towels over you and on your head and you're squeezing cold water on you. Guess what? That's just like putting cold water or an ice pack on the thermostat. What happens? Body heats up. So when you get into cold water, as long as you don't stay in there to the point where you start becoming hypothermic, you actually are increasing your metabolism and body heat. So a lot of people take a cold shower, get into an ice bath early in the day because you get that shot of adrenaline and cortisol. You also get the release of a neuromodulator dopamine, which this is incredible, but there's a paper published in the European Journal of Physiology. It showed that there's a 2.5X huge increase in dopamine release, very long lasting.

• 38:24Speaker 00

  2.5X is the amount of dopamine that's triggered by the use of cocaine. But the difference is cocaine has a very sharp peak on it and then it falls, which is why people become habitual users. But this long sustained increase in dopamine from cold water exposure of anywhere from one to three minutes is really powerful and it increases body temperature. So some people do that early in the morning to wake up as well. And people will probably say, well, how cold? I always say that it really varies. So what you want to do is you, when you want to get into cold, ideally you would submerge yourself up to the neck, but you can also use cold showers. The, the cold should be uncomfortable to the point where you want to get out very badly, but safe.

• 39:09Speaker 00

  And that's the only prescription I can give because I can't say 30 degrees or 40 degrees or 50 degrees because people have different heat tolerance and cold tolerance. And so it should be uncomfortably cold, like you really want to get out of that cold shower. How long to stay in there? Ideally, you would do this for a total of 11 minutes per week. So that could be 11 one-minute sessions. It could be a couple, two or three-minute sessions, or three or four, two or three-minute sessions. But then people say, well, do I end on cold or can I then take a nice hot shower and get ready? Well, if you're me, you take a nice hot shower and get ready for the day. But if you want to increase your metabolism a lot, because this will increase your metabolism, you're looking at fat loss or this kind of thing.

• 39:50Speaker 00

  Well, then you want to end with cold because then you need to use your body's natural mechanisms to heat up, right? So there's a real rationale to all this. I confess, I don't do the cold shower thing every day. I much prefer the sauna or a hot shower or bath. And that, if you think about it, works in the same way. When would be the best time of day to do that? Well, you could do it anytime, but the best time for things like growth hormone release, for cardiovascular health, and for a number of other effects would be to do it in conjunction with the cold, and we can talk about that, or in the evening. Why in the evening? Because you want your body temperature to cool off in the evening, right? Well, if you get into a warm environment, provided you don't stay in there for too

• 40:32Speaker 00

  long, you're not in there for an hour or two and becoming hyperthermic, you get into a sauna for 10 or 15 or 20 minutes, your brain sends a cool-off signal because it's effectively like putting a heating pad on the thermostat. Saunas are hard for most people to access, but likewise, a hot bath before going to sleep for many people is very useful. And it has a number of other effects. I mean, if you're going to do heat-cold contrast, probably best to do, you know, 15 to 20 minutes of heat and then three minutes of cold, 15 to 20 minutes of heat, three minutes of cold. But frankly, I often don't have time for all that. So I'll just do, I'll get into the cold, I hate it, I hate it for one to three minutes,

• 41:14Speaker 00

  I get out, I'm always glad I did it, then I'll get into the sauna, and then I'll take a shower and head to work or something like that.

• 41:21Speaker 02

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• 41:53Speaker 04

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• 41:55Speaker 03

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• 42:18Shane Parrish?

  All right, some quick questions before we get into some longer ones. Do you cycle your supplements at all, or do you just do them every night, the three that you mentioned?

• 42:25Speaker 00

  Yeah, I do them every night unless I pass out reading without them. And I've never developed a dependence on any of them. I do notice that, you know, if I don't take them consistently, then I'll start, you know, my sleep isn't quite as good. There are two other things I should mention that I do use, just in full disclosure. I do take about 200 milligrams of GABA. I've been doing that lately because it really improves my sleep, and I'm really big on sleep. And I sometimes will take a gram or two of glycine as well. So I'm taking a lot. I'm taking bisglycinate, I'm taking apigenin, I'm taking theanine, I'm taking GABA, I'm taking glycine. But why am I doing all this? Well, I fall asleep and

• 43:07Speaker 00

  stay asleep for about six to seven hours, and I feel completely charged during the day. To me, sleep is the foundation of all mental and physical health. And I'm not somebody who struggles with clinical depression. I'm 46 years old. I feel great most all of the time, even if life is hard. And that for me is sort of a wow, I can't believe it, right? Given my work schedule, given life is challenging, now I have a wonderful life, but I also a number of challenges like anybody else. And I think, what's different? Well, what's different is that I've been getting really good sleep consistently for years now. I didn't finish

• 43:49Speaker 00

  up with melatonin earlier. I'm not a fan, not a fan of melatonin supplementation. Dosages are much too high. It's a hormone that interacts with the other hormone systems of the brain and body. Mostly, the dosages are much too high. What you take in terms of one milligram melatonin, very small dosage, is something like 100 times what you naturally secrete. I get really concerned about this, especially in kids, because melatonin is actually the hormone that suppresses the onset of puberty. I don't have any direct data in myself, but... I'm not interested in taking a hormone, exogenous hormone that suppresses the sex steroid hormones, which are testosterone and estrogen, powerful hormones in men and women for all

• 44:32Speaker 00

  sorts of things. And I know that a lot of people just they go testosterone, men, estrogen, women, but that's not the way it works. They're present in both. And actually, having sufficient levels of estrogen for men, provided it's not too high, is important for brain longevity and health. It's actually really important for libido. A lot of people that get on hormone replacement, men that get on hormone replacement will take things like an AstraZol and they'll start crushing their estrogen and they run into serious sexual side effects. So you want these things working naturally, hormone therapy or not. And melatonin just, it causes all sorts of problems. So I know that the melatonin supplement manufacturers probably don't like that I say this, but melatonin is, I don't think should be just taken the way that people

• 45:16Speaker 00

  take it, like M and M's. Maybe occasionally for jet lag, but don't rely on this powerful hormone. It disrupts a number of other systems.

• 45:23Shane Parrish?

  Do you read in bed or do you read on the couch and then go to bed?

• 45:27Speaker 00

  I'll sometimes read in bed. Typically, I'll read on the couch or work on my computer on the couch. I no longer bring the laptop into the room. And now that you ask it, I don't tend to read in bed so much. I've kind of converted the bedroom into only bedroom activities, you know, and not a place where I work.

• 45:45Shane Parrish?

  Do you take naps at all?

• 45:47Speaker 00

  I do. I'm a big napper. I love taking a 20 minute nap or doing an NSDR in the afternoon. The rule on naps, and Matt Walker and I agree on this, is that naps should be shorter than 90 minutes and they should, you should only take them if they, if they don't disrupt your nighttime sleep. There are several very good papers that were published in the last few years in the journal Cell Report, showing that short naps and NSDR, I should say, has some good science to support it, accelerates neuroplasticity and learning, especially if you take that nap within four to six hours after a very intense learning bout. There's something about that sleep state that allows the brain to rewire. And most of the rewiring

• 46:29Speaker 00

  and neuroplasticity occurs during deep sleep, but also during these short sleep bouts that we call naps or NSDR. So I'm a, I'm a huge fan. One thing that's really, I should mention, if people are having an afternoon crash. Uh, one thing they can do to support themselves is to delay their morning caffeine for ninety to one hundred and twenty minutes after waking. The longer you're awake, the more there's a buildup of a, of a molecule in the brain and body called adenosine. And that's sort of a sleepiness molecule, if you will. Caffeine inhibits adenosine function. It basically parks in the receptor and prevents adenosine from working. So if you wake up in the morning, you're, and you're blitzing caffeine

• 47:10Speaker 00

  like I am this morning, um, but I've been up for a while. You're drinking caffeine straight out the gate. What happens is whatever residual adenosine was in your system is still floating around. You've blocked where it can bind to the adenosine receptor, so it's not making you sleepy. But then sometime right around one or two PM, when that caffeine wears off, all of a sudden there's this glut of adenosine and you feel tired. When you wake up in the morning, if you delay caffeine, the cortisol peak actually is able to clear out the remaining adenosine that happens to be around, but it requires, uh, gets a little technical, but it requires an interaction with the receptor. So if you keep caffeine out of your system for the first ninety to one hundred and twenty minutes of waking and then have your caffeine, you'll notice that you'll push through

• 47:54Speaker 00

  the afternoon just fine without any, um, afternoon drop. It also allows you to drink less caffeine overall because a lot of people are just habitual coffee drinkers, um, which I, I happen to really enjoy coffee and I drink yerba mate is my other preferred source of caffeine.

• 48:10Shane Parrish?

  It seems common, at least among people that I know, that they can fall asleep like right away, almost instantly, but then four to five hours later, they're wide awake. You sort of mentioned depression. What else is going on there? Work us through your mind in terms of, uh, how to handle that and, and you know?

• 48:27Speaker 00

  Yeah. So a couple of things. One is they might not be getting enough physical activity during the day, or they're getting too much. They're overtrained. If you train too much and too often, uh, you'll find that you can't get enough sleep and you're always tired. If you train too intensely, you'll often find that you, um, you'll, you'll have this waking up, um, agitated thing. Now that's, that's, uh, I wouldn't get too bogged down in that, but it's something to keep an eye out for. People that are doing tons and tons of miles on the road and then they're always exhausted. Well, your body's just not recovering and. Likewise with work, if you just work, work, work and just burning yourself down. An appropriate amount of physical exercise each day is going to help you get the appropriate amount of sleep.

• 49:09Speaker 00

  And the rule of thumb from the literature is about 150 to 180 minutes per week of zone two cardio. So this is cardiovascular exercise of any kind where you could have a conversation, but you're a little bit strained, you'd prefer to be quiet to keep it going. Zone two cardio, 150 to 180 minutes a week, approximately, broken up into various sessions. And then it's very clear that the body and brain and the skeletal system and the muscular system benefit from any, from a minimum of six sets per body part per week, just to maintain muscle. I'm not talking about people building muscle. I'm talking about people like my mom, who's in her, you know, late seventies, should be doing six sets a week of quadricep work.

• 49:52Speaker 00

  That, that will help sleep, the 150 to 180 minutes of zone two cardio and getting resistance exercise, you know, three or four times a week. You're going to be a much more fuel efficient, better sleeping, more focused system, without question. There's tons of science to support why that's the case. In fact, there's this really cool study, I'll just mention, that was done at Stanford recently by my colleague, Tony Weiss-Cory, where they take the blood from exercised individuals and they infuse it into non-exercise individuals and all sorts of aspects of brain function improve. There's actually stuff secreted from the muscles that then go off to the other organs. This makes total sense when you hear about it because it, you think, well, how could that be?

• 50:33Speaker 00

  But it, the rationale is that the, the other organs of the body don't know what the other organs of the body are doing. So they need to receive signals. So when the muscles are working, the brain says, oh, I need to keep the neurons that are responsible for motor function and memory, they, outside improvements in memory and outside of, there's patients in this study, really amazing. So there's that, there's the exercise and effort component. I don't think we were designed to just think and, and scroll and text. I think we were designed to move and that's vitally important. The other thing is that many of the people waking up after four or five hours were supposed to go to bed earlier. Remember melatonin puts you to sleep, but doesn't keep you asleep. So many of these people might be going to bed at 11 o'clock.

• 51:14Speaker 00

  Waking up at three or four AM, like, ah, here I am again, when actually they need to go to bed at nine. Now, there's this weird asymmetry in the way that our system is built in that we can push through fatigue, but it's very hard to make ourselves fall asleep. So, some people need to discover that they actually were meant to go to bed earlier. I, I know people think about night owls and morning larks and this kind of thing. That's a big idea and industry. And to some extent, it's true, there are genetic polymorphisms that relate to these things. But for the most part, most people were, you know, evolved in, under conditions where they went to sleep shortly after the sun went down. I do think that there is something powerful about going to bed a little earlier.

• 51:56Speaker 00

  There, I keep asking Matt Walker if there's any science to support this, and he tells me no. But I find, and many people find, that every hour of sleep before midnight recharges them more deeply than the hours after midnight. And I don't know what this is, but I find if I go to bed at nine o'clock and I'll sometimes wake up at midnight. I'm like, ah, it's only midnight, what am I gonna do? But then I fall back asleep, I'll wake up at three or four AM and I'm ready to go. And, and that's, that's great. I mean, you can get so much done in the hours between, you know, four and seven AM. Fewer distractions, your focus can be very high. The problem is, most people are going to bed late, they're waking up at four or five hours later. Then they're scrolling on their phone because it's a very kind of passive sensory input.

• 52:41Speaker 00

  They're trying to get themselves back to sleep, it doesn't work. And then throughout the day, they're working at about 75% capacity. So I would encourage those people to just start going to bed earlier.

• 52:51Shane Parrish?

  I want to briefly touch on caffeine and alcohol. Maybe we can start with alcohol. What happens when someone has a glass or two of wine or an after dinner cocktail? How does that impact our sleep? And is there anything we can do to counterbalance the effects of booze in the moment? Just acknowledging that it's probably gonna happen to get a better sleep.

• 53:10Speaker 00

  I think that the key is to not do it too close to sleep. I think obviously hydration is key because alcohol is dehydrated. Remember, a lot of the negative effects of alcohol on sleep are by way of the temperature system. Remember, we used to hear that, oh, you know, if you drink and you're outdoors, I guess we've all had the experience of partying and you're outside and you're not wearing a jacket and it's freezing cold and you feel fine, right? And that's because of the way that alcohol, um, actually, it's, it's a little bit counter to, alcohol actually lowers your body temperature, but your perception of that lower body temperature is disrupted. So, part of the reason you can fall asleep when you drink alcohol is because it lowers your body temperature.

• 53:51Speaker 00

  Now, there's a dosage component and so on, but one idea would be, if you're going to drink alcohol, hydrate. The supplements I refer to, at least to my knowledge, that don't, um, interact with alcohol.

• 54:06Speaker 00

  Obviously, the deadly combination is alcohol and any kind of barbiturates or sedatives. So there, there's actually a strong incentive for staying away from sleep medication if you're drinking, right? I mean, people, a lot of deaths have occurred just because people combine sedatives, um, prescription sedatives with alcohol. But the supplements I'm referring to, um, as far as I know, don't do that. There's a loss of sodium in your system, um, when you drink alcohol because you secrete a lot of fluid. Neurons run essentially, uh, the way they're able to function is from three main electrolytes. It's sodium, potassium, and magnesium. The actual firing of your nerve cells is because sodium enters the cells, potassium goes out. So, a lot of people will feel better if they'll drink water with some electrolytes.

• 54:49Speaker 00

  So that will make a big difference in terms of reducing hangovers and improving sleep. You want appropriate amounts of sodium, potassium, and magnesium in your system. Salt has gotten kind of a bad rap, um, but there was an article published in Science Magazine, which is one of the premier three apex journals in science, uh, about the, the whole myth around salt. I mean, it's true that people with chronic hypertension need to avoid salt, but for most people who are consuming enough fluid, salt is great. I mean, salt is something that brings volume, it keeps your blood volume up, keeps your brain feeling alert and focused. A lot of times, people will feel jittery during the day, they'll think they had low blood sugar. Take a little bit of, take a pinch of salt, put it in some water, maybe a little lemon juice to kill the taste, and drink that. You notice you're just rock solid. Why?

• 55:34Speaker 00

  You might have been low blood pressure or low sodium. Sometimes people can't focus and they are low sodium. Sometimes we crave sugar and we're actually low sodium. This isn't wishy-washy, new agey California stuff. This is really like- This is goes right down to how our kidneys function and blood volume and how the brain requires a certain amount of blood pressure in order to have enough blood going to our brain in order to be able to focus. So when we drink alcohol, we're inhibiting all these things. You're excreting sodium, you're lowering body temperature. And of course, it makes you feel kind of drowsy. Now, about 10% of people have a genetic predisposition to get a big dopamine increase from alcohol. Alcoholics have to be afraid of this and and people who have this need to be

• 56:18Speaker 00

  on the lookout for alcoholism. I have a good friend who, when they drink, they experience this dopamine surge. So they can drink and drink and they feel alert and they feel great and they want to party. They it's not that their tolerance is high. They actually have a dopamine response to alcohol, whereas most people, it's more of a GABA sedative type response. And after one more drink than they normally can handle, they're just ready to pass out or they're kind of heading into the blackout type drunk stuff, which is really bad. So just keep in mind that alcohol can have different effects on different people. But for most people, a drink or two, hydrate, hydrate with electrolytes. And then when you wake up in the morning, you also want to hydrate with electrolytes. That's that's really key.

• 57:01Speaker 00

  And I think that can offset some of it. I think that can offset some of it.

• 57:05Shane Parrish?

  What about caffeine? Maybe you can walk us through what we know about it and how we can use this knowledge to get better performance while minimizing the impact on sleep.

• 57:14Speaker 00

  Caffeine, as I mentioned, is in it. It works, it's actually a competitive agonist of adenosine. So how does it work? Caffeine parks in the adenosine receptor. Remember, adenosine is this molecule that builds up the longer we've been awake. So parks in that receptor. And so it's an agonist, meaning it can park there. But it outcompetes the adenosine. So it creates an artificial state of alertness that way. But it also triggers the release of adrenaline, also called epinephrine. Epinephrine and adrenaline are the same thing from the brain and body. Two sources, there's a you have your adrenal glands above your kidneys. That's one source. And then you have a collection of little neurons in your brain stem called the locus rulius. Locus rulius is an amazing structure.

• 57:59Speaker 00

  It sends those little wires we call axons off into different areas of the brain, acts like kind of a sprinkler sprinkler system, releasing epinephrine and creating states of alertness in the brain. And caffeine stimulates those neurons to release adrenaline. So it literally creates wakefulness in the brain and wakefulness in the body through locus coeruleus in the brain and the adrenals in the body. In addition, it does something really cool, which is that it increases the sensitivity of the dopamine receptors. Now, we haven't talked too much about dopamine, but dopamine is perhaps the most powerful neuromodulator. It's involved in movement. That's why people who have Parkinson's are deficient in dopamine neurons and they have trouble generating smooth movements.

• 58:42Speaker 00

  So they shake, they have trouble, in severe cases, they can't speak, they feel depressed because dopamine is not, we hear about dopamine hits, it's in in other areas of the brain and body such that it controls motivation, craving and drive. And dopamine makes us feel good, but it really makes us feel motivated. People who are deficient in dopamine have trouble with focus, they have trouble with motivation, no disrespect, but they are the people that can sit around thinking about the things they need to do forever. They are chronic procrastinators and they have very, very high, what we call activation energy and they're just not very motivated. Dopamine can be enhanced by taking various things and doing certain things we could

• 59:23Speaker 00

  talk about, but caffeine increases the sensitivity of dopamine receptors, increasing not just the tendency to move by release of adrenaline, but makes us more motivated to go out and pursue goals. In fact, the major effect of dopamine is to place us into a mode of what we call exteroception, of focusing on things that are outside our immediate experience or the confines of our skin. Create the company, get the grades, find the mate, forage for food. This is an ancient generic mechanism that was designed to carry over to most every pursuit activity of any kind. So caffeine increases dopamine function by increasing dopamine receptors.

• 1:00:02Speaker 00

  I am a fan of taking caffeine or drinking caffeine early in the day. I, as I mentioned, I think yerba mate is one source that's great. Some people like coffee, some people like espresso. Just make sure you hydrate and make sure you're getting enough salt as you hydrate. You don't need to buy any fancy electrolyte solution. You can just take a little pinch of salt and put it in water for every coffee that you drink or espresso that you drink. You'll find you feel much better. In fact, in some South American countries and in Europe, they'll give you some water with your coffee. They sort of understand this relationship of the dehydration. And caffeine causes the excretion of sodium by way of the kidney. So I would stop drinking caffeine around two or three in the afternoon.

• 1:00:45Speaker 00

  Many people find that they can drink caffeine until eight or nine P M. And then still fall asleep, but the quality of your sleep will be greatly disrupted. So try and taper that off toward the afternoon. But there's some other fun things that you can do with caffeine. One of the things is to become a bit of an intermittent caffeine user. It's a little hard to do, but if you're somebody who really relies on caffeine, you can try deleting caffeine for a morning and then doing it the next day. You'll immediately feel the rewarding properties of it, of like how great it tastes and how charged you get. So if you get to the point where you're drinking more and more caffeine and you're not getting the great sensations and motivation from it, you're probably too caffeine adapted.

• 1:01:28Speaker 00

  You're not going to feel burnt out from drinking too much caffeine. What's happening is the caffeine isn't working anymore because you've saturated all your receptors. So avoid overuse, stagger the use. You know, I actually think it's a good resilience exercise every once in a while to just skip caffeine for a day. Some people get headaches and that's because caffeine affects blood flow. This is kind of interesting. If you have a headache, sometimes a little bit of coffee can help that headache. Depends if you're caffeine adapted or not. For people that are caffeine adapted, the way that caffeine works is going to be, it's actually going to help dilate the blood vessels of the brain and body. So it's going to actually allow more blood flow. If you're not caffeine adapted and you don't drink caffeine very often, it's going to

• 1:02:10Speaker 00

  constrict those blood vessels and make them essentially make it harder to relax. So, you know, this gets a little technical, but.

• 1:02:20Speaker 00

  There's some fun things you can do with caffeine, like mix it with theanine. If you feel like you're overstimulated, you could take 100 milligrams of theanine and you could adjust down your level of jitteriness. Some people really like that caffeine plus theanine combination because it's that alert but calm. Whereas when they just drink caffeine, they're just too buzzed and they can't focus.

• 1:02:40Shane Parrish?

  Let's chat about subordinating impulses, which I think is sort of a good segue here. It seems like the source of almost all of our problems come from a lack of impulse control. And what I find interesting about this is it's not that we're not capable of making rational choices, but more we're not even aware in the moment we're being irrational. We're reacting without reasoning. And in popular books, it seems like they make it easy and say, well, if you're driven by feelings, you're reactive, and if you're driven by values, you're proactive. But I'm curious to hear your take.

• 1:03:10Speaker 00

  Yeah, I'm fascinated by this. You know, most of the disorder and dysfunction in the world is caused by lack of impulse control. Let me just think about all the people that tweet something stupid and then lose their jobs. Or, you know, or we hear these cases of like, wow, like the person was on a Zoom and they did something inappropriate, not by accident. It's wow, they really have a hard, people have a hard time suppressing their behavior. And they lose things that they've invested tremendous amounts of resources in. Some of this is relates to biological drives that, you know, primitive drives. You know, you hear about people who have made fortunes or have wonderful families. And then they go and have a one off affair with somebody and they lose a lot, right?

• 1:03:55Speaker 00

  They lose relationships, they lose reputation and just think, wow. So do we conclude that the forces of the hypothalamus that drive us towards certain types of behavior are more powerful? Maybe, although maybe it's, we should look at it from the other side and just say, well, maybe they were just actually far weaker in terms of impulse control across the board. And maybe that's what made them effective because they were very action oriented. I have someone in my life, I won't mention who they are, who likes to say about themselves, they're all tactics, no strategy. And they're an extremely effective person. They can make more happen in 45 minutes than anyone else I know, but they have no long-term strategy. It's really. And it's gotten them into some serious hot water.

• 1:04:39Speaker 00

  But in any case, so there's an area of our neural circuitry called the basal ganglia. The basal ganglia are vitally important for controlling and integrating thought and action. And they have two main circuits that are both regulated by dopamine. But they use different receptors for dopamine to have different effects. In fact, opposite effects. Some of the circuitry in this basal ganglia pathways are involved in what we call go functions, like pick up this thing or lean into the work. It's go, it's action oriented and that includes thought. And then the other one is no go. And there's a, it actually involves certain neurotransmitters, including dopamine to suppress behavior.

• 1:05:23Speaker 00

  So what we learned as kids is actually a lot of no go type behavior. It's sit still, don't interrupt. Okay, it's not just clear your plate from the table. It's not just be kind, say thank you. Those are go type behaviors. It's sit there, it's the two marshmallow task. And beautiful work has a two marshmallow task, of course, being the study done at Stanford many years ago and repeated many times. Seems like I'm citing only Stanford studies. I realize there are other universities, but a lot of great work was done there where they give the kids an option to have one marshmallow now or two marshmallows if they wait. Those videos are very cute and it's fun to watch that the kids will sit there that use all sorts of distraction strategies. One of the kids like starts getting close to the marshmallows, some turn away, others sniff them.

• 1:06:07Speaker 00

  And they've tracked these kids over time. And indeed, there are some data to support the fact that kids that were able to defer gratification do better in life. It's not, the studies are not as robust as we once thought, but adults have a lot of problem with delayed gratification. They're just not very good at it. And so one thing that I've done over the years to try and reinforce these circuits in myself, based on my understanding of how they work, is every day I try and have somewhere between 20 and 30 no goes. And the no goes can be trivial, like I'm ready to pick up my phone. No, and I force myself to not pick it up. And all I'm doing is trying to reinforce that circuit because the thing to understand about neural circuitry is that it's generic.

• 1:06:51Speaker 00

  It doesn't, it's not designed so that you have a strong no-go response just to picking up your phone. It actually carries over to multiple other things. And this is also true of the go circuitry. Maybe this is the problem we're in. We heard years ago, and I think it's still a wonderful thing from Admiral Craven, you know, you get up, you make your bed in the morning. Why? Well, I have a friend from the SEAL teams. He's like, well, you know, the McRaven narrative was you do it so that at the end of the day, even if you have a miserable day, your bed is made. And I heard that and I was like, well, I like the idea, but frankly, seeing my bed made at the end of the day doesn't do that much for me. I actually think it's a much more powerful underlying mechanism. And no disrespect to him, great admiration for McRaven, I love his work and what he's

• 1:07:34Speaker 00

  doing. But, but I think that at any moment, we can be back on our heels, flat-footed, or forward center of mass. That's the way I try and visualize the waking portions of my life. Sleep, of course, allows you to toggle between these states more easily. So get that sleep. But we're, you know, at any moment, we're kind of like feeling defeated, we're flat-footed, we're forward center of mass. And forward center of mass takes energy, but it also has its own momentum. And so I think getting up and doing something without involving rumination, or consideration, or thought, just getting into action, sets your whole nervous system into a mode of go. And I think we, then we drink caffeine. It's a go stimulus. Then we move towards the things that are important to us. We're emailing. We're always doing go, go, go, go, go. Even if you're scrolling on your

• 1:08:17Speaker 00

  phone, it's go. Scrolling Instagram or something, it's a go type function. We rarely rehearse our no-go functions. And no-go functions are simply about suppressing behavior. So if you have a meditative practice, there's a little bit of that, where you think, oh, I don't want to do it, but I'm going to force myself to sit still, even though I want to get up. That's a no-go. But think about it, if you get better at meditating, you actually have less of an opportunity to get into this no-go mode, right, to trigger this circuitry. So what I try and do is introduce Twenty or so no-gos throughout the day that I deliberately impose on myself as I'm about to get into reflexive action. And it could be delaying a bite of food for a couple of minutes.

• 1:09:01Speaker 00

  I realize it sounds almost like an eating disorder thing, but that's for people with eating disorders probably want to stay away from that one. But there are all sorts of ways that we can do this. We find ways that we are short-circuiting this process. And so I think we need to keep these no-go circuits trained up. I think nowadays, there's so much opportunity and so much reward for go that we don't train the no-go pathways. One that I think works well for me is oftentimes if I'm training in the gym, I'll have a set routine and then I'll start changing it. I'll notice that I'll have this impulse to, I'll give a dumb example, but just because I want to make it concrete, you know, you're doing one exercise and suddenly you'll go to alternate limb. It's like, why did I do that? I had a plan, right? I should stick to that plan.

• 1:09:43Speaker 00

  So the no-go there is to not default to something more spontaneous. It's to force into really enforced regimen. And I think what happens is, is we become adults, there isn't anyone supervising us making us do these things quite as much. And the phone has allowed for so much context switching and so much opportunity for go, go, go, go, go, that pretty soon you've got hours of your day that are gone that were not structured. So I'm not talking about becoming neurotically attached to these no-gos. What I'm talking about is keeping the blade sharp on both sides. Keeping the goes intact, getting up, making your bed, getting into action, doing things. But also forcing myself to not check the phone, to not check email, to stay in a groove of focus.

• 1:10:28Speaker 00

  And that's actually where there's the greatest opportunity. I'm a big believer in 90-minute focused workouts. And of course, in that time, attention drifts and there's the temptation to get up, go use the bathroom, get up and get a cup of coffee, get up and do anything but what I'm doing. But I try and just really create tunnel vision, even if I'll just sit there and go, this is miserable, I can't focus on this, but not allow myself to go do something else, unless it's... There's a real urgent need. And this is actually the way I trained myself to study in college. It was a little bit masochistic, but I used to sit down, set a timer, and I wouldn't let myself get up for any reason, for any reason whatsoever. And I think I've lost some of that over the years, so I'm trying to build up the circuitry again. A good friend of mine, Pat Dossett, from the, he did nine years in the SEAL Teams,

• 1:11:13Speaker 00

  and he's a big believer in keeping these circuits tuned up. And he said, uh, we always do a certain challenge each year. The other day, he said to me, he's like, how about in 2022, we do the hour of pain? And I was like, oh no. Turns out the hour of pain is where you sit in a pretty uncomfortable position, and you have to remain in that position for an hour. I was like, that sounds great. That sounds like a really great, low-cost, miserable way to build up these no-go circuits. Cold water, you could do for a little bit longer, but eventually you're going to get hypothermic, right? Heat, you could burn yourself. Exercise, you could damage yourself. But one hour of pain, so I, I gotta try this. So I think we're, we're gonna do it.

• 1:11:50Shane Parrish?

  Breathing and vision seem to not only affect our state of mind, but also our body. When we're stressed, for example, our, our field of vision like narrows and we, we have blind spots, not only with what we can literally see, but also with what we can cognitively see. Can you maybe take us through the relationship that vision and breathing have on our internal state? And any behavioral practices that we can use to feel better and see more?

• 1:12:13Speaker 00

  Yeah, so we'll start with vision. Um, when we are relaxed, we are in panoramic vision. Even without moving our eyes or head, we actually have a wider aperture of field of view. Those from special operations communities will understand this as situational awareness. You have to be relaxed in order to see what's going on. Why? Well, the moment that you have adrenaline in your system, uh, goes up, your field of view actually narrows, the pupils dilate. So, you know, um, police will look at, see how high people are by, if people are super relaxed, their pupils are very small. And if they're very, um, agitated, their pupils will be large, agitated or excited in a positive way. When the pupils are large, there's a movement of the, the lens of the eye. And actually, your visual field narrows, you get a soda straw view of the world.

• 1:12:58Speaker 00

  So when you're very stressed, you have a narrower aperture. And you're actually viewing the world. Um, just imagine trying to identify something in a scene by looking through binoculars, much harder actually than if you have the entire panoramic view.

• 1:13:13Speaker 00

  So stress in the visual system, relaxation in the visual system, I'm linked together. There's actually a simple practice that you can do if ever you're in conversation or in an environment where you're stressed, you're trying to find a plane gate that you're running to, you're trying to find somebody, God forbid you've lost your kid, you actually want to dilate your gaze, you can consciously do this by, you can do this even now, just as we're talking, you can start to, you don't move your head or eyes, it's fine to blink, but what you're trying to do is see the periphery of the room, the ceiling, you actually want to see your body in the visual scene that you're in. Actually, your motion detection goes up fourfold when you're in this panoramic vision mode because of the, you shift to a different category of neurons that are much better detecting motion. Whereas when

• 1:13:55Speaker 00

  you go into kind of watch, watchmaker's mode, you are looking for things that are happening over a very small space. And in the visual system and in the brain, this is really the key thing, space and time are linked. So if you have a narrow field of view, you're actually measuring smaller time increments, you're micro slicing your environment. And you're micro slicing it in space and time, whereas when you have broad swath of vision, you actually have bigger time bins. And here's a good example of it, if you are, you need to get home and you're in line at the grocery store nowadays, you know, some places you're even in a mask, which is kind of uncomfortable. And the person in front of you is returning something, it's going to seem like time is going by very, very slowly because you're

• 1:14:38Speaker 00

  micro slicing, you're getting higher frame rate. Okay. However, when you're relaxed, it doesn't bother you at all, you're actually batching time in bigger swaths. And so the visual system drives your time perception system. Okay. So if you're feeling stressed in conversation or public speaking or anything where you want to remain covert about that stress and you want to relax in a way that's covert, dilate your gaze, just try and open up the aperture of your field of view. The other thing you can do is exhale, because in a very straightforward way, inhale, speed up your heart rate and exhale, slow it down. You've got this muscle called the diaphragm, the diaphragm is, is unique to mammals, it's

• 1:15:19Speaker 00

  really incredible, but it's, it's incredible because if it's a skeletal muscle, it's actually can be, it can work voluntarily in the background, or you can take control of it. When you breathe in, Your lungs expand, the diaphragm moves down. And what ends up happening under those conditions is that your heart actually, because you create a change in the amount of space in your thoracic cavity, you change the flow of blood through your heart. Because as you inhale, diaphragm moves down, there's a little more space, heart gets a little bigger, and the brain sends a signal to the heart to speed the heart up. When you exhale, the diaphragm moves up. There's actually a contraction of the heart in the thoracic cavity.

• 1:16:03Speaker 00

  It's a little smaller, the blood flows faster through that smaller volume, and the brain sends a signal to slow the heart down. Simple way to remember it is inhales, speed your heart up transiently. Exhales, slow it down. So if you get stressed, exhaling is the key. Now, there's another way to de-stress, and this is the fastest way that I'm aware of to de-stress. My lab works extensively on this, but it's something that's actually been known since the 30s, and that's what are called physiological size, S I G H. Physiological size are actually something that you do every five minutes or so in sleep or wakefulness. You're breathing, you're working, whether or not you're holding your breath or you're stressed, every five minutes or so, you do this. You reinflate your lungs.

• 1:16:48Speaker 00

  Because the lungs aren't just two big bags of air, they actually have hundreds of millions of little sacs called epioli. And remember, you bring in air, you have trachea, it then creates a lot of volume by branching into the lungs. And you have all these millions of sacs. If you were to lay them out, it would be about as big as a tennis court. Huge volume inside of you. And air, oxygen, can actually move from those little sacs directly into the bloodstream and deliver oxygen to your brain and body. When you exhale, you dump carbon dioxide. Now, the stimulus to breathe in is from neurons that sense carbon dioxide. When you aren't breathing enough, carbon dioxide levels go up, and then it forces you to take a breath. As you get stressed, or if you under breathe, or if you over breathe, these little epioli sacs collapse.

• 1:17:33Speaker 00

  So now you can't bring as much oxygen in, and you can't offload as much carbon dioxide. And also, they are moist. So because of surface tension, if you just take a big, deep breath, let's say your stress one says, "Take a deep breath," and you go, they don't open, they don't reopen, because they're sticky. A double inhale, with the second inhale being a really kind of sharp inhale, will reinflate those little sacs. So it's

• 1:18:02Speaker 00

  So the idea is you take a big, deep inhale and then you sneak in another inhale, even if you feel like you're not getting much in. Ideally, the inhales are done through the nose. So again, it's inhale.

• 1:18:16Speaker 00

  And then long exhale through the mouth. That double inhale through the nose, followed by a long exhale through the mouth, will rapidly de-stress you. So much so that most people find they just need to do it once, sometimes two or three times, in order to go from a state of real kind of stress and anxiety to feeling completely calm.

• 1:18:34Shane Parrish?

  Is that why kids do that when they're crying? Or adults do that when they're sobbing too?

• 1:18:38Speaker 00

  Yes, when we sob, we are effectively asphyxiating ourselves. That's the... Because if we think about sobs, sobs are mostly exhales. "Huh, huh" is the crying thing. That's my weak attempt to cry on cue. But you're collapsing those little sacs and then there's a "huh", this kind of thing, okay? People with sleep apnea do this every once in a while. They're falling asleep, they're in sleep, and they're basically asphyxiating themselves. People who are very large, and that includes, by the way, people, not just people who are obese, but people who have a lot of muscle, who have big necks. Oftentimes, they sleep on their back in their mouth breathers. They're basically oxygen starving themselves. And then they'll "huh, huh", they'll do this kind of physiological science.

• 1:19:21Speaker 00

  The body's attempt to off low carbon dioxide and bring in more oxygen. There's a well-known neural circuit for this involving an area called the parafacial nucleus, discovered by Jack Feldman at UCLA. I just mention those things so that if people want to dive deeper into this, they can. If you're in a claustrophobic environment, actually, if you're in a crowded elevator or something, there isn't much oxygen nowadays, also because people are in the masks, every once in a while, people will take off that mask finally if they're outside, right? And they get, they're allowed to do that. I don't know where people are in the world, but here, we've got a lot of mask girls. And all of a sudden, it's this big...

• 1:19:57Speaker 00

  That's the physiological sigh. So the double inhale followed by an extended exhale is a great way to rapidly bring down your level of what we call autonomic arousal, which is this fancy language for de-stressing. It works great when you're running, too. If you have a side stitch, this is kind of an interesting aspect of the side stitch. A lot of times, people get a side cramp. That side cramp isn't a cramp at all. That side cramp that you feel is actually, you have a nerve called the phrenic nerve, P-H-R-E-N-I-C, that innervates the diaphragm and controls the diaphragm, and it has what's called a collateral, a little branch that goes to the liver. And a lot of pain that we feel in the body is what's called referred pain, where you

• 1:20:40Speaker 00

  feel it in one area because branches of nerves split off. Oftentimes, they'll feel it in their shoulder, too, because the phrenic actually kind of courses up and around near the shoulder. And so they'll have some shoulder pain, they're side cramping, and they'll think, "Oh, I have a cramp or something. I need to run with my hands above my head, or I need to drink more electrolytes." Try, do a physiological sigh two or three times while running, and the cramp will relieve itself ninety-nine percent of the time. And because of the way that it relaxes the diaphragm, and so you're taking out that collateral pain. So I think that the physiological sigh is a great tool. It's not completely covert, because if you're in conversation with somebody and you do it, you know, they might spot you.

• 1:21:23Speaker 00

  But you can do it in conjunction with panoramic vision, dilating your vision. You can do it in most any situation besides, I suppose, underwater. Now, a lot of people are benefiting from nasal breathing more generally. And I always say, unless you're speaking or you're exercising hard, nasal breathing should be your default. Also, in sleep, nasal breathing should be your default. There's a wonderful book called Jaws: A Hidden Epidemic by Sandra Kahn and Paul Ehrlich, both colleagues of mine at Stanford, with a foreword from Jared Diamond and also from Robert Sapolsky. So a lot of heavy hitters on this book. Talks about the cosmetic benefits and the health benefits of being a nasal breather.

• 1:22:03Speaker 00

  The nose has mucosal lining and has a microbiome that filters bacteria and viruses far better than breathing through your mouth. Being a mouth breather is terrible. It actually disrupts the aesthetics of the mouth in kids. They've done twin studies. One kid's a mouth breather, one's not. And the whole jaw structure, the nasal structure improves when you become a nasal breather. And it's very plastic over time, so you can correct things over time. A lot of people say they can't breathe through their nose because they have a deviated septum. Guess what? The way to get better breathing through your nose is breathing through your nose. The reason you have a deviated septum is because you're a mouth breather. There are rare exceptions where if people boxed or they had a broken nose or something like that. But your sinuses can learn to dilate. So learn to be a nasal breather.

• 1:22:46Speaker 00

  One fun way to do that, that isn't too embarrassing, like taping your mouth, is you can take a sip of water when you exercise and run with that sip of water in your mouth. You learn how to nasal breathe. I like to do laps in the pool every once in a while. I don't have access to a pool too much anymore, but I used to like to swim with my nose just above the surface of the water, but my mouth underneath. And I'm only going as fast as I can where I can continue to nasal breathe. People look at me like I'm crazy, but you know, at least I'm not a mouth breather.

• 1:23:16Shane Parrish?

  Brains deteriorate with age. What exercises for the brain have demonstrated either slowing or reversing some of this natural process? Is it just cardio like we talked about earlier?

• 1:23:26Speaker 00

  Yeah, so this is really interesting. So there are great data from the Nobel Prize winning neuroscientist Eric Kandel's lab at Columbia, showing that when we do certain forms of exercise, there's a hormone-like molecule that's released into the bloodstream called osteocalcin. Osteocalcin is known to provide support to neurons in a brain area called the hippocampus, which is involved in learning and memory. The 150 to 180 minutes of zone two cardio per week will support overall brain health and function by way of improving blood flow. So a lot of cognitive dysfunction is over time and age-related dementia is just poor perfusion of the brain. This is why people have general cardiovascular issues also generally have issues with thinking, quite honestly.

• 1:24:11Speaker 00

  Now, in terms of brain function, a couple of things I just want to mention before I forget. One of the ways to improve cognitive function is to make sure that there's appropriate amounts of lymphatic clearance. The brain has its own lymphatic system. This lymphatic clearance happens during sleep. One way to enhance it is to have the feet slightly elevated 10 to 15 degrees. I put a pillow under my ankles when I sleep at night. Usually in the middle of the night, I realize I kicked it away or something like that. But feet elevated naps of about 10 to 15 degrees are very useful. It increases the lymphatic clearance. There's beautiful data to support lymphatic clearance as an important process. Now, in terms of exercise, exercise during the day increases the rates of lymphatic clearance at night.

• 1:24:54Speaker 00

  So, the reason I mention this is that these are indirect effects on lymphatic clearance and blood flow. Now, what about direct effects? The direct effects bring us to osteocalcin. And the direct effects of exercise on brain function and health actually come from stimulation of the skeleton and load-bearing exercise. And this is something that I think is underappreciated. When we do cardiovascular work, again, you support blood flow, lymphatic clearance, but osteocalcin is made by the bones. Wow, hormone that's made by bones, that's released into the bloodstream and then goes to the brain and improves brain function. And how does this work? Well, when the skeleton has load-bearing, is load-bearing, then osteocalcin is released,

• 1:25:39Speaker 00

  and it makes perfect sense. Why would the brain continue to support its own function if the body isn't being used? Well, you could say, how does the brain know that the body is being used? Because osteocalcin is that signal. Again, the brain and body have to communicate. And it's not like the body says, "Oh, I weight trained today," or "I did calisthenics today." No, it doesn't work that way. There's a hormone signal to communicate that to the brain. So this can be achieved a number of different ways. I actually think body weight exercises can be quite good. There are a couple of online sources that, I mean, I think the incredible work that Ido Portal is doing, I D O Portal, he's big on this movement, he calls it movement culture,

• 1:26:20Speaker 00

  but this is not just doing push-ups and burpees and not that sort of thing which are very linear, but a lot of dynamic, nonlinear movement. He talks about explosiveness, suppleness, in basic form, people doing push-ups, sit-ups, pull-ups, dips, jump squats, you know, basic load-bearing behaviors.

• 1:26:41Speaker 00

  It's actually well established that cognitive function in aging can be assessed indirectly by grip strength. Now, why would that be? You have lower motor neurons, which are neurons in your spinal cord that control contraction of the muscles, that by releasing neurotransmitter onto those muscles. But you have upper motor neurons which control deliberate motor action. And grip strength is something that really involves those upper motor neurons. And you actually can do this as a, as a test that if you're lifting weights, if you grip really strong, let's say you're even doing a unilateral movement, if you clinch the opposite fist really, really hard, you'll find that you can move more weight for more repetitions, because you're engaging the entire upper motor neuron to lower motor neuron system.

• 1:27:23Speaker 00

  So there's a chain of neural events there. So the idea is that people should be doing three to four days a week, minimum, of some sort of load-bearing exercise. That could be weight training with machines or free weights, but it could also, again, be push-ups, pull-ups, dips, jump squats. The ability to jump and grip strength are highly correlated with cognitive function later in age. Why would that be? Again, it's these hormonal signals sent from the body to the brain. And I think that, you know, the overwhelming amount of evidence has been placed on cardiovascular exercise and improvements in the brain, even so much so that people have focused on, there's some mouse data, or studies published on mice,

• 1:28:04Speaker 00

  showing that exercise, cardiovascular exercise can increase the number of neurons in the hippocampus. Turns out that's true for mice, but not for humans. I wouldn't focus so much on adding new neurons to the brain. It's more about getting the ones that you have to already be, to be more functional. And I think that one of the reasons why so much of the work was done on cardiovascular exercise is very easy to make mice run on a wheel. They love to run on a wheel. Harder to get them to lift weights. If you want mice to do load-bearing exercise, they actually do these kind of cruel experiments where they actually make a limb deficient, so that they can, I have to hobble around on another limb to overload that limb. And just one more incentive for doing load-bearing exercise, there's a beautiful

• 1:28:46Speaker 00

  paper published this last year showing that when people do resistance exercise, a little, what's called a micro RNA, which are little tiny RNAs, as the name suggests, actually are released in little vesicles, little bubbles from the muscle and travel to the body fat and help facilitate burning of body fat. So resistance exercise has Obviously affects some caloric burn that can indirectly support fat loss in states of, you know, subcaloric intake, but resistance exercise itself facilitates lipolysis, the usage of body fat for energy. So, so many reasons to both do cardiovascular work, 150 to 180 minutes a week minimum, and to do three to four days a week of resistance

• 1:29:30Speaker 00

  exercise. And it doesn't have to be excruciatingly hard or heavy. It does have to be effort, but it pays off through this osteocalcin system.

• 1:29:39Shane Parrish?

  Dude, I could talk to you all day. I got one last question today, but maybe we can do another episode next year just on mental performance and learning. But one aspect of mental performance that doesn't get a lot of attention is that we often get into these ruts that totally undermine us. Like, for example, somebody cuts us off, or we feel slighted or wronged by someone. Is there a way that we can use the body to control the mind and let go?

• 1:30:02Speaker 00

  Yeah, that's an interesting question. I mean, I agree, we get into these, these ruts. I think there are a couple of things to remember. And I say this with a lot of sensitivity. I really do. One is that most people are not mentally healthy. Doesn't mean they're mentally ill, but you know, most people have not done a lot of self-reflection work in a way that translates to their behaviors. Most people sadly grew up in families where there was at least some unhealthy dynamics. Most people are stressed, and a lot of people shed their stress on to others. And so, you know, we're constantly being bombarded with dysfunction. I'll take us out of this, this swamp in a minute, but a colleague of mine, who's a psychiatrist, years ago, when I started teaching, he gave me some great advice. He

• 1:30:46Speaker 00

  said, just remember, 1% of people have clinical schizophrenia, 4% are bipolar, 5 to 10% are clinically depressed, another 10% have anxiety. He listed off OCD, all these syndromes. I thought this is a sort of, and he said, now, when you get your feedback from your course, be sure to pay attention to the things that you need to do better. But please understand that as you move through life, you're dealing with, people are struggling. And I thought, wow, I had no, you know, it's true. So when you look at comments online and someone says something crazy, I mean, there's a very high probability that they're dealing with a mental disorder of some sort. So.

• 1:31:25Speaker 00

  If you're somebody who is moving through life and feeling bombarded by a lot of quote-unquote crazy behavior, just remember that there's a lot of struggle out there. And if you're somebody who's really into self-optimization and you're doing a lot of work on yourself, maybe you've been doing some therapy or journaling or work on traumas and you're optimizing your hormones and sleep, you are in a very small category, unfortunately, of people that's really trying to be healthy for yourself and for others. So, the first thing I say is that, the second thing is, after age 25, the brain doesn't change unless it's self-directed change. So, don't expect anybody to change unless it's self-directed. Forget trying to get people to change. It does not work.

• 1:32:09Speaker 00

  It works with children, it does not work with adults unless it's self-directed plasticity. And there is tons of literature to support that statement. Now, as we move forward in life, though, if we are healthy and functional, it's our job to step into leadership roles and to demonstrate healthy behavior. How do we do this? I think that one thing that we can do is raise our stress threshold. You know, we talk about, these days, there's a lot of quote-unquote "trigger warnings" and about being triggered and everybody's getting triggered. So, one way to look at all this is that, okay, is to eliminate the problems, the people triggering. The other is to reduce your trigger threshold.

• 1:32:51Speaker 00

  And I think that trying to reduce the amount of problems in the world by forcing or encouraging other people to change is just generally not that good. You offer tools, that's what I do, that's what you do, and you just hope that people will take them. But we can increase our stress threshold so that our trigger threshold is much higher. And the way to do that is a self-directed practice that my lab has been working on for a while now, and some people recognize this as Tummo-type breathing or Wim Hof-type breathing. The truth is, it doesn't actually have to be done with breathing. You could do this with ice baths, you do this with any resilience-increasing behavior. What you need to do is get comfortable and stay in a no-go response.

• 1:33:36Speaker 00

  Under conditions where you have high levels of adrenaline in your system, uncomfortable levels of adrenaline. That can be done by getting into an ice bath. That can be done through what we call cyclic hyperventilation. We're running a study on this now. Actually, the data are in. It's just not published yet. Cyclical hyperventilation means sitting or lying down for, take, you know, we found that five minutes a day actually is very effective, even though it's very brief. And it looks a little silly when I do it, but I'll just do it. Cyclical hyperventilation is going to be a big active inhale through the nose and then a passive exhale through the mouth. So this, you just kind of let it fall out. But you repeat that 25 to 30 times. So I'm not going to do it 25 to 30 times. I'll do it five times just to demonstrate. So it's big, active inhale. It's work. This is work.

• 1:34:21Speaker 00

  It's going to feel like work. It's

• 1:34:32Speaker 00

  So you do that 25 to 30 times and you're going to feel agitated. What's happening? You are generating adrenaline release into your system. I can already feel like a little bit of blood flow, heat, heating up. You're generating adrenaline release. This is different than running up a hill. This is active stimulation of adrenaline into your brain and body. Then after 25 or 30 breaths, you exhale all your air

• 1:34:59Speaker 00

  through your mouth and you hold your breath and you try and be as calm as you can for about 15 to 60 seconds. Don't try and hold your breath too long, just when you feel the stimulus to breathe. Go back into it, 25 to 30, big active inhales, passive exhale, big active inhale, passive exhales. And you'll notice a tendency to want to shorten the inhales, but try and really do a full inhale, passive exhale. Then you exhale all your air again. Sit there for about 15 to 60 seconds until you feel the impulse to breathe. Then you do a third round, 25 to 30 of these big inhales, passive exhales. Then you exhale all your air, 15 to 16 seconds. And then you take a big gulp of air.

• 1:35:45Speaker 00

  Lungs full, then you're gonna sit as calmly as possible as you can with lungs full. And at that point, you'll thank me, because what's gonna happen is you're going to feel a kind of mild euphoria. You're going to be very alert, extremely alert, because your system is filled with adrenaline, but you're gonna feel very calm. There's also dopamine release at that point. And then, when you feel the impulse to breathe, please don't pass out, just, just exhale and start breathing normally. This done, we had people do this daily, but if you do it on a regular basis, maybe even just three times a week, what you'll notice is really incredible. You actually, when things happen in your

• 1:36:28Speaker 00

  world, people will say something, or you won't feel that sharp spike of adrenaline, you've raised your stress threshold. So we hear a lot about grit, resilience, and mental toughness, but those are just psychological terms. What we're talking about here is the how to build grit, resilience, and mental toughness. And so, this is very similar to the kind of cold water torture that they do for, you know, SEAL Team screening. It's it involves some goes, because you have to do these breathing things, as we talked about earlier, go-type behaviors. There's also a lot of no-go. The no-go is sitting calmly while your system is filled with adrenaline. And there's another perk of all this that's very relevant right now, which is that there's a beautiful study published in the Proceedings

• 1:37:10Speaker 00

  of the National Academy of Sciences that shows that when people do this kind of breathing, prior to an injection of E. coli, something I don't recommend people do, they are actually able to remain symptom-free in the face of that very serious infectious injection. Why? Well, this breathing, and adrenaline in particular, activates the immune system in a way that allows you to counter infection. So, the other day, I got off a plane, I've been traveling a lot now, planes are starting to get more crowded, there was a lot of coughing and sneezing on the plane, I was like, oh god, like, this is the last thing I want. I mean, I feel... Pretty safe in general about all the other stuff going on, but you know, colds and flus,

• 1:37:52Speaker 00

  we haven't been exposed much, so we're all a lot more vulnerable. I hate being sick. So I got off the plane, got outside, took my mask off, and I immediately did this round of breathing in order to get that stimulus. Unfortunately, I'm not sick. But it's a great tool for activating the immune system, great tool for building up that stress threshold. You could do it by getting into ice baths or cold water, but I really like this practice. And again, it's a little early to report the specifics, but we had people do this just five minutes a day. And we see some really impressive effects on mood, on countering anxiety, on improvements in sleep. And it makes you a tougher person, basically. Don't do it near water or in water because you could pass out and drown.

• 1:38:34Speaker 00

  But aside from that, don't do it while driving, the obvious stuff, right? Be rational. But it's a great practice. Takes a little bit of effort to get into, but I guarantee that if you do it three or four more times a week, you're going to notice a big improvement in your ability to not get triggered. Someone's gonna say, it won't feel triggering because there's no adrenaline response to it. You've raised your stress threshold.

• 1:38:57Shane Parrish?

  Let's end with what is success for you?

• 1:39:00Speaker 00

  That's a hard question, but a really good one. Well, I place tremendous value on certain things, and I think some of those will be obvious. So I'll just list those and then I'll try and give a more succinct answer. I'm not a good philosopher. But you know, the things that have really made a huge difference in my happiness in life are, first of all, feeling physically and mentally well is our own individual obligation. Regardless of upbringing, no one can do it for us. There's no magic pill or fairy or stork that's going to deliver the solution. So I place tremendous value on keeping my physiology where it needs to be. I want to have endurance, I want to have strength, I want to have mental strength, I want to have kindness,

• 1:39:43Speaker 00

  I want to have openness, I want to be open to learning. Friendship to me is the bedrock of my well-being because I depend very heavily on it for the feeling that life is moving forward. And that's just unique to my own experience. But I think you don't need many friends, but friendship is a wonderful. An important part of my life. So I try and take good care mentally and physically. I try and invest in my friendships and obviously other relationships too. Success to me really is about embracing this capacity that we have to to improve our nervous system. It really is. It's not just a job for me. It really is. I feel my duty as a

• 1:40:26Speaker 00

  human being to always try and be better, do better for myself and for others. And that involves having tools and protocols, being reflective. There are so many ways that we can improve and there's so many ways that we can devolve when we don't do that work. I'm a big believer in the psychologist Erickson's stages of development. He talked about these different stages of development that at every age, we're working through some fundamental conflict. And if we can resolve that conflict, that then we can advance to the next stage. And the ages are somewhat plastic because of changes in culture and life. But I started off as developmental neurobiologist and development doesn't end

• 1:41:09Speaker 00

  at 25. Your whole life is one big developmental arc. And so I'm 46 now and I try and think, okay, what have I managed to accomplish? And then what's my work? What's my, what do I need to do? For instance, I don't know much about spirituality at all. I intend on learning. I didn't grow up in a particularly religious family. I don't even know that my goal is to set out to do that. But I feel like at this stage of life, according to Erickson, if you've resolved a career, you've resolved relationships to some extent, you've resolved your relationship to yourself to some extent, and that's an ongoing process. What's the next thing that we face? We face to try and understand how we are short lifespan, relatively speaking, fits into a larger and more coherent whole. And so that's the

• 1:41:51Speaker 00

  work I'm doing. So I look at life as a success to me is is looking at life as a series of developmental milestones and making sure that if I didn't hit any milestones in the past, for whatever reason, that I take responsibility for meeting those milestones. And looking forward and where I'm at now, I just try and say, well, what are the milestones that I should be working on now so that I find myself at 50 and 60 and 70, hopefully beyond that? Having checked off the boxes that make for a full life. It's hard to go back and take care of things of past. We can't be super performers at everything, so that's not what it's about. But I really believe, I think that Erickson was quite correct in understanding that our

• 1:42:34Speaker 00

  nervous system changes over time and that we need to meet these milestones. Nothing bothers me more than regressive behavior. I see a lot of that in the world now, adults acting like children, just kind of regressive reactivity, even just the little exercise that we did a moment ago of trying to raise stress threshold. I feel like adults need it just as much and maybe even more than children, because I think we've become collectively regressed. And that includes me. I'm no better than anyone else. I just try and put the work in to try and resolve these milestones. So that's where I'm at with, in terms of what I see as successful. In terms of my professional life, I mean, I have a very simple and, to me, important mission, which is I just want to share the beauty and utility of human biology. That's my goal.

• 1:43:17Speaker 00

  That's why I have a podcast, that's why I go on podcasts, that's why I have social media. I just want people to understand what is to know about and what we understand about the body and brain in ways that can help improve their lives and the ways that they interact with others. And so that's my singular mission, and I'll continue as long as that feels like the right one.

• 1:43:43Shane Parrish?

  Andrew, thank you so much for taking the time today. This was an amazing conversation, so informative and so deep. I have so many more questions for you.

• 1:43:51Speaker 00

  Well, thanks so much for having me on. I'm always happy to sit down and have a podcast, have a conversation at any point.

• 1:44:02Shane Parrish?

  The Knowledge Project is produced by the team at Farnham Street. I'd love to get your advice on how to make this the most valuable podcast you listen to. Email me at [email protected]. You can learn more about the show and find past episodes at fs.blog/podcast. To get a transcript of this episode, go to fs.blog/tribe or check out the show notes. Can you do me a small favor? Go online right now and share this episode with one friend who you think would love it. Thanks for listening and learning with us. Till next time.