The School of Greatness - Andrew Huberman on How Nutrition, Exercise, Tech & Sex Affect Your Sleep EP 1455

Episode Date: June 17, 2023

The Summit of Greatness is back! Buy your tickets today – summitofgreatness.comIn this episode, Dr. Andrew Huberman, a neuroscientist at Stanford University, discusses how to become better sleepers. He highlights the importance of understanding the factors that affect sleep quality. One key aspect he mentions is the role of light exposure, emphasizing the significance of getting sunlight in the morning to regulate sleep-wake cycles. Dr. Huberman also addresses the individual differences in caffeine sensitivity and advises understanding one's own reaction to caffeine for better sleep planning. Additionally, he explores the benefits of napping, particularly with elevated ankles, which is suggested to enhance the glymphatic system's clearance of waste from the brain. Lastly, Dr. Huberman provides insights on managing pre-bedtime anxiety, suggesting that channeling it into productivity can be beneficial.In this episode you will learn,How sleeping poorly negatively affects you.The main things that prevent you from sleeping well and how to fix them.How nutrition and exercise affect sleep.What is happening in the brain when we sleep.For more information go to www.lewishowes.com/1455More from Andrew Huberman:Eliminate brain fog: https://link.chtbl.com/1204-guest

Calling all conscious achievers who are seeking more community and connection, I've got an invitation for you. Join me at this year's Summit of Greatness this September 7th through 9th in my hometown of Columbus, Ohio to unleash your true greatness. This is the one time a year that I gather the greatness community together in person for a powerful transformative weekend. People come from all over the world and you can expect to hear from inspiring speakers like Inky Johnson, Jaspreet Singh, Vanessa Van Edwards, Jen Sincero, and many more. You'll also be able to

dance your heart out to live music, get your body moving with group workouts, and connect with others at our evening socials. So if you're ready to learn, heal, and grow alongside other incredible individuals in the greatness community, then you can learn more at lewishouse.com slash summit 2023. Make sure to grab your ticket, invite your friends, and I'll see you there. There are a number of risks to not getting enough sleep. Deficits in learning, deficits in the immune system, reduction in testosterone and estrogen in both men and women. So disruption of hormones, disruption of gut microbiome. Until you are sleeping long enough and deeply enough, 80% of the nights of your life, you are functioning suboptimally.

Welcome to the School of Greatness. My name is Lewis Howes, a former pro-athlete turned lifestyle entrepreneur. And each week we bring you an inspiring person or message to help you discover how to unlock your inner greatness. Thanks for spending some time with me today. Now let the class begin. Welcome to today's special episode. Over the last 1,300 plus episodes, there have been so many impactful interviews that I've been lucky enough to have, and I always like to reflect on some of the most powerful. And this episode was one that resonated with most of you guys in the past, and I'm excited for the value it's going to bring you today as well.

So I hope you enjoy today's episode. Sleep is something that I feel like when I grew up, I was told, sleep when you're dead. You know, the athlete, the business mentality was like, broke people, you know, sleep a lot. You know, those who are making money are going out and working burning the midnight oil but then later in my 30s I realized how important sleep was for me to recover to remember to have emotional regulation throughout the day and not be reactive and defensive so can we break this down and your thoughts about sleep and how you frame this, some of the research and the science that you've studied around this and what we should be thinking about around sleep?

Sure. So sleep is the fundamental layer of mental and physical health. If there's one thing that we should all be doing is working toward sleeping long enough and deeply enough 80% of the time. I think that 80% is a good goal because things happen. Travel happens, kids happen, illnesses happen. The weekend, you're going out or whatever, yeah. Until you are sleeping long enough and deeply enough,

80% of the nights of your life, you are functioning suboptimally. And what's the biggest risk then if we're not getting enough sleep? Okay. So there are a number of risks to not getting enough sleep. Deficits in learning, deficits in the immune system, reduction in testosterone and estrogen in both men and women, so disruption of hormones, disruption of gut microbiome, increased cancer risk. There are a bunch of things. The severity of those things depends on a lot of other things too. Prior health,

other health conditions, context, age, occupation. If you're not getting enough sleep and you're a high-rise construction worker, it's different than if you're an office worker. So we need to sleep enough. Now, what's enough sleep? This is an interesting question. Enough sleep has been argued. It's six hours. Other people, it's seven hours. Other people, it's eight hours. It's basically waking up without an alarm clock and feeling rested. Insomnia is actually a medical term nowadays. And insomnia is essentially diagnosed as falling asleep during the middle of the day due to lack of sleep at nighttime. But many people who are having trouble sleeping at night are not falling asleep during the middle of the day. They're dealing with grogginess or crankiness or other effects of having fragmented sleep.

What are the main causes of not being able to fall asleep? Is it rumination? Is it traumas that you're holding on to? Is it arguments? Is it self-doubt or insecurities? Is it you nap too much? Is it the foods you ate too late? What would you say are the main causes of not being able to fall asleep? All of the above. But the primary one is a failure to turn off your thoughts. Okay. And I think that might provide a good anchor point for us to talk about some protocols. Really a excellent night's sleep begins in the morning. I talked about this on the previous episode, so I won't go into detail, but everyone should get as much bright light in their eyes, ideally from sunlight, first thing in the morning, 10 to 30 minutes outside, depending on how bright it is. Eyeglasses or contact lenses are fine.

Don't wear sunglasses if you can do it safely. If you wake up before the sun rises, turn on bright lights, then go outside once the sun rises. If you have no access to sunlight, use a daytime simulator or similar like a ring light and get that light in your eyes. So that's all of that in a compact form. Caffeine. You can inhibit falling asleep with caffeine. You have to figure out when your threshold is. For me, I can drink caffeine up until about three, even four o'clock in the afternoon and sleep like a baby. And still sleep well. Yes. And Matt Walker, our good friend, Matt Walker, would say that my sleep isn't as good as it would be had I cut caffeine out earlier. By like 11 or 12 a.m. Right. And I want to acknowledge, you know, Matt is the Michael Jordan of sleep science. And so I'm not going to. You're the LeBron James. Well, no, no. And thank you for the compliment.

But no, I'm not. I know a lot of the science and the protocols, but that's Matt's wheelhouse. And so if he says something, it's true. And if I say something and our opinions conflict, it's likely to be something that the data are still emerging or in that case default to Matt being correct because I just out of due respect for his expertise. So caffeine, you know, for some people they can have a two o'clock espresso, 2 p.m. espresso, some people it's 4 p.m. Some people can drink caffeine at 8 p.m. and fall asleep. But there

I would say it's problematic because you're disrupting the architecture of sleep and the brainwaves associated with sleep, the chemicals and so forth. So get that morning light. Cut your caffeine off at the time that allows you to fall asleep. That morning light also sets a timer on your melatonin rhythm. So you have this gland in your brain called the pineal gland. That pineal is the source of melatonin. Melatonin makes you sleepy, but it does not keep you asleep. Melatonin starts to rise in the late evening and continues into the night and then eventually tapers off.

This is naturally occurring melatonin release, not supplemented melatonin release. release. The fastest way to slam melatonin into the pavement and eliminate it in your system is to look at bright light for, I hate to tell you this, even a few seconds. You mean at night? At night is typically when melatonin rises. It's when it's released in the bloodstream and when it has this effect of making us sleepy. It does a number of other things too. You want more melatonin at night, is that right? right you do and if you wake up in the middle of the night or it's eight o'clock and you decide you want to go to bed at nine or it's nine o'clock you want to go to bed at ten you go into the bathroom and you flip on the bright lights your melatonin levels just got crushed down so having lights on is a the worst thing you can do yes and it doesn't matter if it's blue light, red light, purple light, green light, bright lights inhibit melatonin

very acutely and therefore you want to avoid exposure to bright lights at night if your goal is to be asleep. So the simple rule that governs all this stuff is when you want to be alert, get bright light in your eyes, ideally from sunlight. So that's true in the morning and throughout the day. And when you want to be sleepy or asleep, avoid bright light in your eyes. Now, many home environments don't allow you to have zero lights and that's not actually necessary. You can just dim the lights in the evening. Ideally, you also avoid overhead lights because the neurons in the eye that trigger this melatonin suppression and so forth, they reside in an area of the eye that views upper visual space. So you could have desk lamps and just dim those down. If you're going to work on a screen, dim it way down.

Will blue blockers help? Yes, but if the light is bright enough, you're still going to inhibit melatonin release. So how bad is watching TV at night? If the TV isn't too bright. And it's farther away. Farther away. Yeah. And maybe you wear blue blockers.

Yeah. I mean, some people take this to the extreme. They wear sunglasses. I think that's a little extreme. Now, candlelight and moonlight, surprisingly, doesn't seem to block melatonin. Now, maybe a really bright moonlit night, full moon, the lunacy associated with the full moon might actually be due to a suppression of melatonin and an increase in alertness. So those are the things as it relates to light. Then there's this issue of people who have

trouble staying asleep. So they can fall asleep fine, but they wake up at two or three in the morning. I happen to do this. If I go to bed around 1030 I tend to wake up around 3 and I use the restroom Yeah, I tend to drink a lot of fluids and I have to use the restroom. This was true at every age This is not just some aging related thing That's fine. I just keep the lights dim and use bathroom and you go back to fall back asleep very normal very healthy one of the best things I ever did for my sleep was to keep my phone out of the room so that when I wake up at 3 in the morning, I just didn't start scrolling the newspapers is typically what I'm reading online. Gotcha.

And then you're just waking up your brain, not just by the light, but by the content. And, you know. You're activating it again as opposed to going back to sleep. Exactly. And sometimes there's a comment and they're like, why is it? You know, your thinking is not very good in the middle of the night. The other thing is you want to keep the room cool.

So in order to fall asleep, your body has to undergo a drop in temperature of one to three degrees. There are a couple of ways to accomplish this. One is keeping the room cool. The other is to, and that's ideal actually

because you can put a hand or a foot out. We actually lose a lot of our heat through what's called our glabrous skin, so the palms of our hands and the bottoms of the feet. I always put my feet out of the sheets and just let them feel the cool air. That's right. And that's a great way to cool off your core body temperature. You're probably doing that unconsciously in your sleep as well.

If the room were too warm, the only way for you to cool off would be for you to put your hand in a bucket of cold water, and people don't have that accessible and then you're gonna go pee if you're doing that too right exactly and then of course there are all these products nowadays of you know things that cover yeah that cover that cool the bed um i'm supposed to try one of these soon i haven't tried one yet i tend to just keep the room cool cool yeah and what do you keep it out i keep it around 67 65. oh that's a little cooler than what I do. I put it at about 67, 68. Okay.

But I tend to wake up hot in the middle of the night, like throw the comforter off and go put some cold water on my face. Wow. So don't obsess over waking up too much. And if you do, try and stay away from screens. Or if some people will read a book, dim light again. Yeah. And if you do try and stay away from screens or if, you know, some people will read a book, dim light again and then falling back asleep. Some people are waking

up at two or three because they are going to bed too late. Their melatonin has run out. So imagine that you're naturally somebody who should go to bed early, around 9. But we all have this ability to push forward and stay awake if we have to. Much easier to stay awake than to force yourself to go to sleep early. Very hard to force yourself to go to sleep. So let's say your system, you start releasing melatonin around 9 p.m., but you stay up until 11. Then you get into bed, you fall asleep around 11.30. And at 3 in the morning, you suddenly wake up. Well, that's because your melatonin tapered off.

And there's a wakefulness that's occurring. And so ideally, you would start going to bed earlier. Now, there's a lot of discussion out there about so-called chronotypes. So night owls, morning people, people that follow a more typical schedule. Typical would be going to sleep somewhere between 10.30 and 11.30, waking up somewhere between 6.30 and 8. Then there are the people that like to go to bed at 2 a.m., sleep till 10. And then there are people that like to go to bed at 8 and wake up at 4. Huge variation out there. It tends to change across the lifetime.

Yeah, you're a season of lie for years. That's right. And adolescents and teenagers tend to stay up later and want to sleep in. And there's actually some evidence that they can learn better if they are allowed to use that schedule. But most schools won't adhere to that schedule. You've got to wake up at 6 and go to school at 8 or whatever. Once you enter adult life, you're generally somebody who's going to have to learn how to go to bed early and wake up early or at least wake up early. Now, naps, you should feel comfortable. up early. Now naps you should feel comfortable,

the data say naps you should feel comfortable napping for 90 minutes or less at any point throughout the day as long as it doesn't interfere with your nighttime sleep. So some people like me, I love naps but it doesn't interfere with my nighttime sleep. It doesn't? It does not. So you can take a 60 minute nap Generally, 20 to 45 minutes. And then you fully fall asleep, or you're kind of like awake and just resting? I can fall asleep anywhere, anytime. In like a minute? I can fall asleep at a gun range, yeah.

What? It's in... Can you sleep sitting up too, like this? Oh, yeah. That's a gift. Plane anywhere. That's a gift. It is, although it could reflect that I'm pushing my system a little too hard.

But it is useful at times. Incredible. You can fall asleep right on a plane or... Anywhere. Leaning against a subway station and anywhere. If I need sleep, I'm going down. That's incredible. Yeah. So the other thing is that during sleep, a number of things happen, and we can talk about slow-wave sleep and REM sleep, but one of the most important physiological functions of sleep is to clear out some of the cellular debris that accumulates throughout the day. The cellular debris creates cognitive deficits. It actually may be related to the aggregation of proteins and things that relate to dementia and Alzheimer's. It's the so-called glymphatic system. The lymphatic system is a system of moving through immune cells and

clearing out of debris from the body. The glymphatic system is a kind of a equivalent system that exists in the brain that involves so-called glial cells, which are support cells, but also do many things actively. They're not just doing support. The glymphatic system is like a washout of the brain's debris. And that system seems to function best when feet are slightly elevated above the brain. There's some interesting data from University of South Carolina coming out now that show that if you can get your ankles elevated a little bit

higher than your chin, that's great. When you're sleeping? While you're sleeping. What's it do for you? It increases the glymphatic clearance. And there's some data that it can improve function of the brain. The studies that are happening now that I'm aware of, I'm in touch with that group, are mainly geared towards people that have had head injuries, so concussion and TBI of various kinds, but they also are seeing interesting effects in typical folks that don't have any traumatic brain injury. So I put a pillow underneath my ankles when I fall asleep to get a little bit of that elevation. And then during the day, if ever you can't get a nap or you are going to get a nap, put

your ankles up on the couch and lie down on the floor. That itself can get some of the clearance of the glymphatic system. And that helps you sleep better, it helps you just clean out the system? It helps your brain function better when you wake up from sleep. Interesting. That's what the data are starting to show. You know some of the things I described like the light viewing, it is baked into the neuroscience literature hundreds of papers, published papers. Some of the things like the light viewing, is baked into the neuroscience literature, hundreds of papers, published papers. Some of the things like the glymphatic system is kind of cutting edge.

It's on the way. But because the safety margins of raising your ankles are so large, I mean, there's nothing dangerous about that. How long do you need to do it for to get the benefits? Oh, I think these are immediate benefits. Two minutes or ten minutes? Oh, no, you're doing this the whole night that you're asleep. Your ankles are elevated.

If you wake up and you happen to kick the pillow out, it's not the end of the world. But the idea is that you don't want to be sleeping with your head above your ankles either. There is some evidence that when people travel on planes and they're sleeping in chairs, that that's not equivalent to the kind of sleep they'd get when they're lying flat. That's interesting. Independent of all the other things that are happening. And we know this because there are great sleep labs at Stanford, uh, school of medicine at UPenn back East and elsewhere, where people actually go into a clinic and sleep either, you know, upright or, or at different

and they're looking at all this at the, at the level of data. Okay. So here's one for you. What's the best, uh, position to sleep on your back, on your side, on your stomach? Great question. And it really, truly depends. And it probably depends on how hot you run. So I tend to run really warm. A lot of the cooling of the body occurs from the palms and bottoms of the feet, but also from the upper back and scapulae because we accumulate what's called brown fat there. It's not the blubbery fat that's under the skin. It's like a furnace. Actually, you can increase the density of brown fat by going into cold water repeatedly for one to three minutes several times each week. It means your furnace actually burns hotter. It allows you to be in cold temperatures more comfortably. Some really beautiful data just published on this. So I don't like to sleep on my

back because I start heating up. Start sweating. That's right. don't like to sleep on my back because I start heating up. Start sweating. That's right, so I tend to sleep on my side. I sleep in that, what is that, it's like soldier position. Yeah, yeah, yeah. But then again, there's some people that have shoulder issues and then they can't do that.

I'm relatively flexible through my shoulders, not super flexible, so I can do that. It really depends. Now of course, if you're sleeping on your stomach, how do you elevate your ankles? You know, it starts becoming a little bit of, you know, we are not just science experiments. And so you have to assume that you're not going to get everything exactly right. But keeping the room cool, keeping the cool being under a warm enough blanket, but then extending a hand or an ankle out so that you could cool off during the middle of the night, that's going to be good. Keep the room dark, although complete pitch black

doesn't seem to be as good as having a little bit of light somewhere in the room. But you don't want a bright blue light or red light anywhere in the room that's going to wake you up. Some people like me have very thin eyelids, exceedingly thin eyelids. Some people have very thick eyelids. So some people are more bothered by a light in the room than others, it really varies. So you have to just tune things to your particular environment. I'm curious about the neuroscience before you go to sleep.

How do we set our minds up to, you were saying before about a lot of people, it's hard for them to sleep because they can't shut their mind off. Right. Is there something we should be thinking before we shut it off to set our sleep up for success mentally and then to really build into the next day where we wake up feeling like clear-minded and without this brain

fog where we have more motivation where we have more you know energy and excitement towards the next day and then doing that in a pattern every night is there any science around that? Is it like listening to a hypnosis? That could be very helpful. Which will help you clean out whatever is going on through the day and get clear and ready for the next day, but also fall asleep so you're not thinking about it. You know, is there anything that can help you have better dreams so that you sleep better?

Like what have you found there in the neuroscience? Yeah, so glad you asked this question. There's some really interesting data from a guy named Chuck Charles Zeisler, who is at Harvard Med. He's done beautiful studies on sleep in humans for many decades and a really fantastic physician and researcher.

And they observed something interesting, which is that about 90 minutes or so before your natural bedtime, there's a spike in alertness, planning, and almost anxiety that all people undergo. And it's a normal, healthy pattern. The idea, and it's a just so story because we don't really know, I nor Chuck Zeisler nor anyone else was consulted at the design phase, as we say. But we assume this came about because prior to going to sleep, we need to shore up everything for safety. We need to lock things down, make sure everything's in its place because we are very vulnerable in sleep.

Nowadays, this might manifest as you need to go to bed at 10.30 because you have to get up at 6, etc. And then right around 8.30 or nine, you start finding yourself running around doing various things. Many people worry about that and they think, oh, I'm really stressed because I actually need to go to sleep and here I am wide awake. It tends to subside very quickly. So just the knowledge that that's a normal, healthy spike in alertness and activity, I think can help a number of people. I want to make sure I mentioned that. The other thing is preparing the mind, as you said, turning thoughts off. Turning thoughts off is a skill.

We've talked before, gosh, almost a year or more now, ago, about Yoga Nidra. Yes. Which is, there are many, many Yoga Nidra scripts available on YouTube free of cost. The ones I particularly like are the ones by Kamini Desai. K-A-M-I-N-I-D-E-S-A-I. Kamini Desai. I just really like her voice. I don't know Kamini, never met her. These are free scripts. They're yoga nidra scripts that last about 20 minutes. They involve some breathing, some meditation type stuff. But they teach you to turn your thoughts off, which is really wonderful because a lot of people, they just get stuck in this rumination. Now, is there an ideal protocol prior to sleep? It depends because some people find they have their greatest clarity after the kids are asleep and they're sitting there. So I wouldn't say don't work or do work. You know, you do want to avoid strong stimuli before sleep. So do you really

want to watch, you know, a politically charged or violent movie right before sleep? Well, that depends on how triggered you tend to be by politics or violence. Some people aren't triggered. Other people are. But, you know, that aside, you don't want to go to bed either too hungry or too full because that can inhibit your sleep. So for most people, that's going to be finishing your last bite of food about two hours before bedtime. But I confess there are days when I work or work, work and, you know, arrive at a place, a hotel, order some food and just, you and just eat a massive meal and then pass out. Again, 80-20. Try and get it right 80% of the time.

What's harmful of being too hungry or being too full before you go to bed? You'll have trouble falling asleep and you'll wake up in the middle of the night. Both extremes. Both extremes. Extremes. Both extremes. And I'm not a nutritionist or nutrition expert, but what I've found works for me personally is I fast until about noon-ish each day. And then my lunch is low carb, so I tend to eat some grass-fed meat, some veggies, maybe some starches if I trained, and a piece of fruit. If I didn't, I don't.

I don't. And then I also have an afternoon snack. But then in the evening, my meals tend to be relatively low in meat and protein because and higher in starches, which activate the tryptophan system and the serotonin system, which makes it easier to fall asleep. You can repack glycogen during the night so you can do muscular work the next day. Training of any kind, but also thinking your brain uses glucose. So at night I tend to eat pastas and vegetables and rice and uses glucose. So at night I tend to eat pastas and vegetables and rice and risottos and things like that. Not in huge volumes, but I tend to eat less protein. It's not that I don't eat any, but I don't tend to eat big steaks right before going to sleep. Again, 80-20, 80% of the time. So foods, certain foods stimulate the neurotransmitter pathways like serotonin that facilitate the transition to sleep. Now, what could you take?

Well, some people will drink chamomile tea. Chamomile tea is enriched in something called apigenin. Apigenin is, I take it in supplement form, 50 milligrams of apigenin, but it's really just chamomile extract. And it tends to make you a little drowsy. And many people experience excellent sleep when they take apigenin, and normally they struggle with it. Again, with supplements, I don't have a relationship to

an apigenin company or anything like that. I want to be clear. And also supplements, check with your doctor, of course, all that. But the one thing I don't recommend is that people take melatonin. Don't take melatonin. I am not a fan of melatonin for the following reasons. First of all, melatonin does many more things besides just cause the transition to sleep. It also is involved in regulating some of the other hormones like testosterone, estrogen, and so on. Most of those studies are animal studies, but some of the data on humans indicate that as well. In kids, melatonin is one of the hormones responsible for suppressing puberty, and then melatonin rhythms change, and then puberty happens. know if your kid has already been taking melatonin uh i wouldn't be

alarmed but just be aware and if you talk to your physician most physicians aren't really aware of this i would talk to an endocrinologist frankly also most math um matt walker would also support this statement because i'm lifting it from him. So, which is that most melatonin supplements contain anywhere from 15% of what's listed on the bottle to 300% of what's listed on the bottle. The regulation of supplements is an issue. Even from a trusted brand, if you were to take say three milligrams or six milligrams of melatonin, it's a pretty standard dose out there. You are taking super physiological levels of melatonin. It's a pretty standard dose out there. You are taking super physiological levels of melatonin. Your system does not see those levels of melatonin.

So chamomile tea is okay. Chamomile tea or apigenin, it's a little hard to find, but apigenin is a great, it's chamomile extract essentially. There are a few other things. Again, There are a few other things. Again, margins for safety will depend. Magnesium threonate, which is T-H-R-E-O-N-A-T-E, threonate. You know, 142 milligrams or so of magnesium threonate. Again, you could just shop for cost. I don't want to name brands, even though my podcast is associated with one.

I don't want this to become about that. The magnesium threonate, many people take in 30 to 60 minutes before sleep with apigenin. Many people find great benefit. I am not a fan of taking serotonin or serotonin precursors, 5-HTP, L-tryptophan prior to sleep for the following reason. The architecture of sleep, as Matt probably discussed here, I need to watch that episode. He's so good. Includes a lot of slow wave sleep early in the night, repair and recovery of motor circuits in the brain, and muscular tissue and connective tissue that might have been worked with or damaged during the day. And the second half of sleep tends to be enriched in so-called REM sleep, rapid eye movement sleep, more dreams that are very intense, et cetera.

That architecture is exquisitely controlled by levels of serotonin at one point and not having serotonin at others, having acetylcholine release being very tuned to particular times in the night. When you start messing with the serotonin system, you disrupt that. So my experience with 5-HTP, I took it to go to sleep or L-tryptophan as I fall asleep, like I got clubbed over the head by a grizzly bear. And then I wake up an hour and a half later and I cannot fall asleep for me for two days. Very intense. Now I'm pretty sensitive to these things, but that's why I'm not a fan of those and i rely on magnesium 3 and 8 apigenin and some people also take theanine but for the time being i think magnesium 3 and 8 and

apigenin or chamomile are great if people don't want to take supplements chamomile tea is a terrific mild sedative to just kind of turn off some of that thinking. Relax, okay. And what about working out and sleep? Okay, yeah. Should you work out in the morning, afternoon, night? How does that affect the sleep when you work out and how you work out? Yeah, well, I wanna be fair to the fact that people have different schedules

and different constraints and that work, getting that 150 to 180 minutes of zone two cardio per week is essential. People should be doing some resistance training regardless of goals or in order to maintain muscle because it's so important to avoid injury and maintain metabolism, etc. So you need to get it in somehow. But you then have to ask yourself what's happening around that workout. So are you going into a brightly lit gym at 11 o'clock at night? I in blasting music and are you drinking three espresso energy drink before you go you're gonna be awake

You're gonna have a hard time going to sleep. It's not just the workout. It's the context around the work. Yes My preference is always to work out as early in the day as possible. That's my preference. I don't always accomplish that We people should also know that if you work out at the same time for three or four days, your body builds in an anticipatory circuit. You will feel an energy increase a few minutes before that workout. So if you are working out at 10 p.m. at night and you're finding it hard to go to sleep, if you can shift that workout earlier in the day, you will soon become a morning person. It might not be as natural as somebody who naturally wakes up at 4.30 or 5 in the morning, but let's say you want to get on an earlier schedule, you want to get that morning light, but also force yourself to work out in the morning and then by the second or third day of doing that

you will start to feel more alert as you arrive to the workout because there are these anticipatory circuits that's cool working out late at night some people say cardio okay but not weight some people say i i think it's highly individual and i don't think there's ever been a really good study addressing that regularity is key i for me, the best times to work out are three hours after waking up, 11 hours after waking up, just based on body temperature rhythms, or immediately, like get up and just put the shoes on and just go. And I don't tend to do that last thing very often these days. I tend to wake up and move through the morning a little bit like a lazy bear in the sunlight and then you wait for my caffeine caffeine.

But every time I do that early morning workout, I feel much better and more alert all day. And you fall asleep probably easily. And I fall asleep much more easily. And the other thing you can do to fall asleep is this might seem a little counterintuitive. I said that you need to lower your body temperature by one to three degrees.

You can take a hot shower or do a sauna, which you would think, well, it heats you up. But when you actually heat the surface of the body, your brain cools off your core body temperature unless you stay in that heat for a very long time. So you take a brief, you know, I don't want to say how long people should get in the sauna or whatnot, and then, or a hot shower, and then, you know, maybe rinse off with some cool water for, not cold, but cool water, lukewarm water, for 10 seconds, and dry off and get into bed. Your body temperature will drop. If you get into an ice bath or a cold shower-

You'll stay awake. It's very jolting. So I don't recommend people do that late in the day unless they want to be awake for some reason at night. But the other thing is, this is a little counterintuitive, but my colleague at Stanford, Craig Heller, works on thermal regulation. If you want to cool down and you put a cold towel or ice around your neck, you're cooling the surface of the body just like you would put a cold pack on a thermostat, what's going

to happen? Your brain's going to start to heat you up. So I would avoid cold exposure right before sleep, especially if it's very stimulating, like to the point cold enough that you get that adrenaline bump. So cold air is key to drop the temperature down. Keeping the room cool.

Cool. Yeah, but you don't want that really. Not like an icebox where you're shivering. Exactly, the acute cold exposure as we call it, of an ice bath or something. Rather a sauna, or a lot of people don't have access to sauna, maybe a warm or hot shower before sleep. But people tend to be very specific about this too. Some people like to shower in the morning, some people in the evening. I like to shower whenever I have an opportunity to shower. Right. Generally, I try and shower after I work out because if I don't, everyone suffers. But I think that if people don't have access to a sauna, that hot shower or warm shower before sleep can be very beneficial because the body will actually start to dump heat and cool off as you get into bed.

Gotcha. In terms of the actual architecture of sleep and dreams, with dreams, you know, that dreams in the beginning of the night tend to be kind of mundane and seem kind of ordinary. And the dreams toward morning tend to be more intense. This is the- You wake up and you remember like what just happened. That's right.

Not what happened in hours before. Right. And the early part of the night, in very broad strokes, the early part of the night tends to be when we release growth hormone, when we tend to repair motor circuits and damaged tissues. And there's a real lack of emotional context to those dreams. Now, the dreams toward morning tend to have much more emotional enrichment

and be very intense. Often if people see visual hallucinations, that's in the so-called REM sleep dreams. Why is that? It's interesting. Great question. Well, two things. You're also paralyzed during REM sleep. You can breathe, but you cannot move. And there's this interesting thing that happens in sleep where when we are in REM, rapid eye movement sleep,

So when we are in REM, rapid eye movement sleep, we have high degree of emotionality of dreams, but we are unable to release adrenaline. This is very much like trauma treatment where there's a desensitization. You're coupling an intense experience to an inability for your body to move or to have a reaction to that. Now, if you suddenly wake up, which I often do, you'll notice that the adrenaline kicks in. But this is kind of like therapy in your sleep or trauma release in your sleep. And if you deprive people selectively of this rapid eye movement sleep,

a number of bad things happen. But one of the primary things that happens that's bad is that when you don't get enough REM sleep, you are more emotionally labile during the day. Little things bother you more. You feel more irritable. Yeah. Anytime I see a comment on Instagram to me or anyone else and someone seems kind of prickly, I always just think to myself, I'm not getting enough REM sleep. Yeah. Or I tell myself that because I want to have some empathy for them. They're just not neurologically up to snuff, meaning they're not working as well as they could. Now, there are other reasons why

people can be combative, but I think lack of REM sleep is one of the main reasons that we feel irritable, easily set off. There are a number of very powerful things that happen in REM sleep that we should all be seeking. So if you wake up in the middle of the night, you really do want to try and get back to sleep. And then as the night goes on, you're spending more, a greater proportion, excuse me, of your sleep in that rapid eye movement sleep. And those are when you have your very rich dreams. And when you wake up, oftentimes spending some time with a pad and paper, maybe while

you're getting your afternoon, your outdoor um is a great thing because you'll remember components of your dreams the meaning of dreams has had uh you know has been debated for thousands of years i would say and i think you i think matt would agree matt walker would agree that some dreams do have tremendous significance. Others do not. There seems to be a very powerful effect of having a dream that makes people want to tell someone else their dream. I think we just have this need to want to put structure on something that seems very unstructured. In a sense, when we're dreaming, we're crazy.

Space and time are completely fluid. Everything's, anything could happen. And when we have a dream that feels powerful to us, I think we understandably want to put some sort of interpretation on it. Meaning behind it. Yeah. I've had great insights through dreams. I've also had a lot of dreams that got me nothing. I wake up in the middle of the night and I tend to write things down that come to mind.

I achieve my greatest clarity for kind of psychological and relational things. When I wake up first, you know, immediately I'll have a solution in my head or I'll think I'm, you know, the other day this happened. I've been, as we were talking about before the recording, I've been working through a very complex set of personal interactions. And these are not traumatic or anything like that, but I've been working with somebody to try and resolve a really hard problem that we have. And we were both committed to solving this problem.

And I'll chip away at this and chip away at this and they are much smarter than I am. So I'm struggling and then I will go to sleep and I'll wake up at three in the morning and boom, the answer, at least to whatever it is that I'm trying to resolve is right there. And I think it's because in sleep, you're trying, you're getting those repeats of the different circuits. They're practicing, you're rehearsing things you learned during the day. You're dumping the emotional load through this trauma release type mechanism of

REM sleep. And then answers just kind of geyser up to the top. But again, I'm speculating. What we do know at the neural level is that there's a replay of the neurons that were active during the day in sleep, but at much more rapid rates. A lot of stuff we won't remember. That's what you're saying. Much of sleep is there. Much of the dreaming and sleep is designed to get you to forget things that are meaningless. What is happening to the brain as you're sleeping? Is it just connecting neurons? Is it flushing? Is it, you know, creating these images for you to remember?

What's like the, what's the actual mechanics of it? Yeah. So several things are happening. One is this glymphatic washout. There's this literally like a spin cycle on the brain of dumping all the junk. That's why you want your legs up. Dr. That's why you want your feet elevated, right? That's why you want your sleep. That's why you want your feet elevated. The glymphatic washout is one. The other is

adenosine, this molecule that accumulates the longer that we are awake. That actually gets reduced during sleep so that we can wake up feeling rested. In other words, if you've been up for a day and a half, you've got tons of adenosine in your system. Caffeine of any kind blocks adenosine function. I want to be careful because it's not actually an antagonist. It's a competitive agonist for the aficionados. But you're basically reducing adenosine function with caffeine.

When you sleep, you reduce adenosine, which is why I delay my caffeine 90 to 120 minutes after waking up. So you've got adenosine getting pushed back down. You've got the glymphatic system wash out. You have reordering of neurons and creation of new connections so that what you couldn't do previously, you can do the next day and the next day. You're learning. The trigger for learning occurs during wakefulness through focused, alert, motivated states. The actual rewiring of neurons, meaning the changes in the connections, occurs during sleep in particular, deep sleep.

So a lot's happening in there. And during rapid eye movement sleep, the brain is incredibly metabolically active. It's just that the body is paralyzed and some people experience this invasion of that sleep paralysis into into the wakeful period it's really scary I've had this happen you wake up and you're still so paralyzed and jolt out you can't move I feel like I'm screaming but nothing's coming out it's really terrifying terrifying it's called what sleep paralysis yes essentially but that's an invasion of sleep paralysis into the waking. It's like wake paralysis, yeah.

And I know you're not a pot smoker, but many pot smokers experience that more often than non-pot smokers for reasons that probably relate to the serotonin system and the so-called atonia, the inability to move during sleep. So there's that. What else happens during sleep. So there's that. What else happens during sleep? Well, there's all sorts of interesting resetting of the digestive system, the microbiome. Are your muscles growing? Muscle growth probably occurs throughout the 24-hour cycle, but a lot of repair of muscles and triggering a muscle growth probably occur during sleep. He's passed now. He was 11 years old when I had to put

him down, but I had this bulldog, Costello. He was a 90-pound English bulldog mastiff. When he was a puppy, I would take a picture of him. And then the next day I'd take a picture of it when he was larger the next day after sleep. Well, they're just growing at such a tremendous rate, right? And that's growth hormone. And during puberty, sometimes kids will be kind of locked up during sleep. You'll go in and see a kid sleeping. They'll be in some weird position. They'll get growing pains because actually the bones, you know, it's a lot to orchestrate.

The growth of the bones and the connective tissue and the brain and all that. It's not always perfect. And so sometimes there's a few days where things are a little out of whack. I remember for months my knees would hurt when I was a teenager. Yeah, and kids, my dad used to come in and push my knees down because he was worried that something was going on that's the growing you're growing you're growing you're growing bones are like spreading that's right they're psychological growing things and they're physical right and in your case there was a lot of growing a lot of physical i'm not i'm not short i'm i'm six one but you're six four yeah you're you're you're a tower six five maybe so

yeah um wow so the there's a lot of stuff going on in sleep. And are you burning a lot of fat too during sleep? Yeah, a lot of metabolism is happening during sleep. There's a beautiful paper that just came out. Gosh, I forget all the micro details. So I'm only going to say a little bit about it. But a lot of the removal of fat from the body from when we burn fat is actually done through the breath. We exhale, there's a carbon dioxide component.

Isn't that interesting? It's a sweat and the breath, right? And then what, just? Not so much fecal elimination, but more that you're breathing out. Breathing burns more fat than? Well, no, no, sorry. Elimination of fat from the body,

if it's going to occur, because I have to be careful because the nutrition crowd online, they have claws, elimination of fat from the body, if it's going to occur, because I have to be careful because the nutrition crowd online, they have claws, pitchforks, and they like to- They come after you. And they're ready, fire, aim type trigger. You said this.

Exactly. So I want to be very clear. I believe in calories in, calories out. Yes. That's a basic principle. There are people out there arguing different, but basically if you ingest more calories than you burn, you're going to gain weight. And if you keep them more or less equal, you're going to maintain.

And if you burn more than you ingest, you're going to lose weight. Okay. Whether or not you lose from muscle fat or other body compartments is a different story, but the utilization of fat as an energy source and the elimination of adipose tissue, of body fat, eventually boils down to something where, yes, indeed, you are exhaling the eventual molecules. Okay, but... That's crazy. Dr. Among other...there are some other routes as well. I mean, there's...

How much fat are we exhaling a week? Dr. Well, it depends on whether or not you're in a caloric deficit or not. If we're in a deficit, then we're exhaling that fat? Dr. Essentially. Well, but it's been broken down into a number of different metabolic components. That's crazy, isn't it? It's really wild to think about. Well, if you think, yeah, and you might think, well, why not just remove it through the digestive

tract? But it's part of a whole lipolysis, meaning the utilization of fat for energy, the lipolysis cycle and an energy cycle. You know, if those of you that enjoyed or suffered through college or high school, you know, the Krebs cycle and ATP and ATP production and the mitochondrion cells and so forth, that was a whole business there. But so in sleep, this paper shows that, you know, each stage of sleep is actually associated with a different mode of energy utilization and carbon dioxide offloading and so forth. Or in the last episode,

we talked about ideally you are nose breathing during sleep. You are not mouth breathing. So some people actually will tape shut their mouth with a little bit of medical tape. Huge benefits to that for getting enhanced oxygenation of the brain and body. You do not want to have sleep apnea. Sleep apnea is associated with sexual side effects in men and women. It's associated with cardiac arrest. It's associated with a number of bad things. A lot of people who are carrying a lot of extra weight who sleep on their back or even just who are carrying a lot of extra weight, unfortunately, they have a buildup of carbon dioxide in their system at night, especially if they're mouth breathing and they

wake up not feeling rested in all individuals, regardless of phenotype, as we say, their genotypes and their phenotypes, regardless of phenotype, the kind of droopiness and the bagging of the eyes that can occur from sleep apnea and the effects on... So become a nose breather. We talked about that in the last episode, how to become a nose breather, but you want to nose breathe during sleep if you can. Yes. And your partner will thank you too, because you're not snoring as

much. Do you nose breathe in sleep? I think I do. I think I do. I'm told I snore a little bit from time to time. And a lot of people, even people who aren't carrying a lot of fat, but people who are carrying a lot of muscle who sleep on their back, oftentimes they are kind of suffocating during sleep. Every time I hear about a bodybuilder or a very large athlete dying, it's almost always a heart attack during sleep. They're on their back. Or their side, but they're asphyxiating.

And there's a beautiful relationship between breathing and heart rate. Simply, when you inhale, your heart rate goes up., when you inhale, your heart rate goes up. And when you exhale, your heart rate goes down. And this has to do with the movement of the diaphragm and the change of the shape of the heart and signals from the brain. I won't go into all that. But when you inhale, your heart rate speeds up. And when you exhale, it slows down.

And that's respiratory sinus arrhythmia for the aficionados. So you want to create an environment around your sleep where it's dim lights in the evening. You've had your meal, maybe a cup of chamomile tea towards sleep. Maybe you use supplements, maybe you don't. You wake up, get sunlight in your eyes. This is the kind of landscape you want to create. Sure. Cool room.

You want to avoid very stimulating stuff, conversations and activity, you know, right before sleep. Now, some stimulating activities before sleep, we won't go into details, have a rebound effect afterwards. Matthew Walker's actually talked about this, how certain types of activities cause a rebound and relax, you know, they're very... So sexual activities. Yes, I'm not trying to be vague here. What does that do for sleep if you have sexual activities. Yes, I'm not trying to be vague here. What does that do for sleep if you have sexual activities before sleep? So sexual activity includes, it's really remarkable at the level of autonomic nervous system. So sexual activity involves an increase at first in the so-called parasympathetic arm of the autonomic nervous system, the relaxation system. at first in the so-called parasympathetic arm of the autonomic nervous system, the relaxation system.

But then it involves increases in the sympathetic arm of the autonomic nervous system. And orgasm in men and women is actually purely driven by the sympathetic nervous system, the stress system. Huh, okay. And then the post-coital period is when the parasympathetic nervous system kicks back on and there's a deep relaxation.

So is it good to have sexual activity before bed or not that good? According to the architecture of what I just described, yes. Yes, it's good? Yes, it's good. Yes, it's good. Yes, it's good. It helps people sleep. And actually when Matt Walker came on my podcast, we talked a little bit about some of the data on this.

Now, even then, you know, so there are all sorts of questions about this that are now coming out. Now, the interesting thing about studying sex in the laboratory is it's very hard to do, right? I mean, there are ethical reasons. There are complicated reasons. And good studies have to be done in laboratories or by self-report and with self-report people lie right and make up stories in one direction or the other they're doing more of what they would like to be they're either reporting more of what they'd like to be reporting of or less of what they would like to be reporting less of but doing those sorts of

studies in the laboratory is very difficult there are sleep laboratories but it's not often that couples are coming in and staying in those sleep laboratories together, although that does happen from time to time. But yes, after sex, there's a rebound in the parasympathetic nervous system, which is a deeply relaxing component of the nervous system. And the reasons for that aren't clear. I mean, one idea is that it's designed to put people in close proximity, not just run off and look for another mate immediately, and to smell each other and pair bond through some of the pheromonal systems. Powerful. Yeah. Yes, very powerful. An interesting form of pre-sleep biology, for sure. And one that, let's be fair, as we were talking about during the break, every species has two main goals,

to protect its young and to make more of itself. And while not all sex is designed for reproduction or used for reproduction, I mean, the whole architecture of the reproductive axis, as we say, from brain down to genitals, is designed for that arc of parasympathetic, sympathetic, and then parasympathetic. That's interesting.

Yeah. Oh, and the duration of that varies between individuals. Okay. That was a joke, sorry. sympathetic and then Paris parasympathetic that's interesting oh and the duration of that varies between individuals okay you got to go at least 10 minutes to get the full effects I'm not setting the parameters that people should or should not follow that is not my domain this is powerful stuff man I'm so I'm so grateful for your wisdom as always Huberman lab make sure you guys check out the podcast one of the top podcasts in the world right now it's incredible people love the science i love the neuroscience what you're teaching over there you got a lot of great stuff

about brain states around fear courage anxiety calm how we can better move into and out of them through visual cues breath work movement supplement, and all sorts of great stuff. Amazing research. Hubermanlab.com, Huberman Lab, everywhere on social media. You go live on Instagram, you post on the podcast every week, YouTube, lots of great stuff. We were talking about this before, and I think this could be a good segue about sex at night. I want to do a whole another episode on relationships and neuroscience around relationships and intimacy i think a fascinating conversation marriage relationships dating all that so if you guys want that conversation from andrew then leave a hashtag in the comments below relationships relationships, and we'll see on YouTube

how many people want to really see that information. And if you're on the podcast, just DM us or post this over on Instagram and tag us both if you want to learn more about the science and neuroscience behind relationships, intimacy, all that stuff. I think it'd be fascinating. Have you done an episode on this yet?

I have not. And I think that there's a lot of really great biology, both about sex and reproduction and about relationships, parent-child couple relationships. The biology of breakups is really interesting. Oh, that'd be huge. And there's some really interesting data on how relationships change over time according to changes in biology in individuals, because we all change over time according to changes in biology in individuals because we all change over time and not necessarily for the worse. The data, just to throw out a little teaser,

you know, there's this idea that testosterone levels drop with age. The data on this say that there are people in their 70s who maintain testosterone levels. And there's men and women both have testosterone. It serves similar roles in both, although different at the level of the body, but at the level of the brain is what I'm referring to, that mimic the levels that were present in their 20s.

Really? Yeah. So it has a lot to do with how people sleep, how they certainly stress their behavior, but also there's a strong psychological component related to self-image that's super interesting. So we can talk about that as well. Dude, this is fascinating. I'm so pumped for this.

Yeah, keep this information for the next time. Oh, yeah. This is going to be good. I won't put it out there. My man. Thanks so much. Thanks, brother. I really appreciate you, Lewis.

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