How to Breathe Correctly for Optimal Health, Mood, Learning & Performance

**Andrew Huberman** (0:00)
Welcome to the Huberman Lab podcast, where we discuss science and science-based tools for everyday life.
I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, we are discussing breathing. Now, breathing is something that we are all familiar with, because frankly, we are all doing it right now, and we do it during our waking states and while we are asleep. And most of us have probably heard that breathing is essential to life. We hear that we can survive without food for some period of time, maybe even up to a month or more. That we can't survive that long without water, but we could survive a few days without water, depending on how well hydrated we are when we go into that water deprivation and the heat of the environment we happen to be in. But that we cannot survive without breathing for more than a few minutes. And that if we cease to breathe, that our brain and our bodily tissues will die. And in fact, that is true. However, despite everybody's knowledge that breathing is essential to life, I don't think that most people realize just how important how we breathe is to our quality of life. And that includes our mental health, our physical health and what we call performance. That is our ability to tap into skills, either physical or cognitive, in ways that we would not be able to otherwise if we are not breathing correctly. So today we are going to talk about what it is to breathe correctly, both at rest, during sleep, in order to reduce our levels of stress, in order to wake up or to become more alert deliberately, and many, many other things, including how to stop hiccuping. This is one of the most searched for topics on the internet. Today, I will teach you the one method that is actually linked to science. No, it does not involve drinking a glass of water backwards from the opposite side of the cup or holding your breath in any kind of esoteric way. It actually relates to the neural mechanisms, that is the brain to body connections that cause the hiccup. Hiccup is a spasm of that neural circuit. And I'll teach you how to turn off that neural circuit in one try. And that's not a technique I developed. It's a technique that's actually been known about for several centuries. And we now know the underlying mechanism. So today's discussion will give to you many tools that you can apply. All of these tools are of course behavioral tools. They're completely zero cost. And in telling you how those tools work, you'll learn a lot about how the breathing, aka the respiratory system works and how it interfaces with the other organs and tissues of the body, in particular the brain. In fact, one of the most important things to understand about breathing right here at the outset is that breathing is unique among brain and bodily functions in that it lies at the interface between our conscious and our subconscious behavior. And it represents a bridge literally in the brain between the conscious and the subconscious. What do I mean by that? Well, breathing does not require that we pay attention to our breathing or that we are even aware that we are breathing. It will just carry on in the background either normally or abnormally. And I'll teach you what normal and abnormal breathing is in a little bit. However, breathing is unique among brain and bodily functions in that at any moment we can consciously take control of how we breathe. This is an absolutely spectacular and highly unusual feature of brain function. For instance, your digestion is carrying on in the background right now, whether or not you've had food recently or not, but you can't simply control your digestion by thinking about it in a particular way. In fact, most people can't even control their thinking by trying to control their thinking. That actually takes some practice. It can be done, a topic for a future episode. However, breathing is unique. Breathing will carry on involuntarily, subconsciously in the background, as I said before, but if at any moment you want to hold your breath or inhale more deeply or vigorously or exhale longer than you inhale, you can do that. Very few, if any other neural circuits in your brain and body allow that level of control. It turns out that level of control is not an accident. It has been hypothesized that by controlling breathing, the brain is actually attempting to control its own state of mind. Now, the way this was originally stated in a scientific research paper was a little bit different. It was a little bit more physiological. The statement was the brain by regulating breathing controls its own excitability. Excitability in the context of neurobiology is how able the brain is to take in new information or not, how able the brain is or not to turn itself off, to go to sleep and to regulate its own levels of anxiety, focus, et cetera. If that seems a little bit abstract, I'll make it simple for you. By changing your pattern of breathing, you can very quickly change what your brain is capable of doing. In fact, a little bit later, I'll tell you that while you inhale, you are far better at learning and remembering information than during an exhale. And it is a very significant difference. Does that mean you should only inhale and not exhale? No, of course not. I'll teach you how to breathe for the sake of learning and memory, as well as for physical performance and a number of other things. So hopefully I've been able to highlight for you the importance of breathing, not just for life, because yes, breathing is essential for life, but that the subtleties of how we breathe, the duration and intensity of our inhales and our exhales, how long we hold our breath between inhales and exhales, very critically defines our state of mind and our state of body, what we are able to do and what we are not able to do. And the great news is we can control our breathing. And in doing so, control our mental health, physical health and performance. Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is however, part of my desire and effort to bring zero cost to consumer information about science and science related tools to the general public. In keeping with that theme, I'd like to thank the sponsors of today's podcast. Our first sponsor is HVMN. HVMN, which is a supplement that increases ketones, can be used in the context of a ketogenic diet. However, many people, including myself, find that increasing blood ketones by using a supplement such as HVMN can greatly improve cognitive ability and physical output for mental work and for exercise, even when not on a ketogenic diet. There's a lot of research supporting the fact that even if you are consuming carbohydrates and you are not in ketosis, that is you are not following a ketogenic diet, consuming supplements that can increase blood ketones can allow you to think more clearly for cognitive work and physical work for that matter, perform at greater output for things like resistance training and endurance exercise. And indeed that's what I found. So I use it largely for preparing for podcasts or other aspects of my scientific work. And sometimes prior to workouts, especially if I'm working out having not consumed any food prior, I find that I have a lot more energy. It also has the property of suppressing hunger. If you'd like to try ketone IQ, you can go to hvmn.com/huberman to save 20%. Again, that's hvmn.com/huberman to save 20% off your order of ketone IQ. Today's episode is also brought to us by Thesis. Thesis makes custom nootropics. And as many of you have probably heard me say before, I am not a fan of the word nootropics because nootropics means smart drugs. And frankly, the brain doesn't work that way. The brain has neural circuits for focus. It also has neural circuits for creativity and neural circuits for task switching and for imagination and for memory. There is no such thing as a neural circuit for being smart. And therefore the word nootropics doesn't really apply to anything specific, neurobiologically speaking. Thesis understands this and therefore has designed custom nootropics that are tailored to your unique needs. I've been using Thesis for over a year now and their nootropic formulas have been a game changer for me in particular in the realm of cognitive work. My go-to formula for when I'm doing any kind of cognitive work is their clarity formula. That's the one I've been using most often lately. If you'd like to try Thesis customized nootropics, you can go online to takethesis.com/huberman. You'll take a brief three-minute quiz and Thesis will send you four different formulas to try in your first month. Again, that's takethesis.com/huberman and use the code Huberminute checkout for 10% off your first box. Today's episode is also brought to us by Whoop. Whoop is a fitness wearable device that tracks your daily activity and your sleep, but goes beyond that by providing real-time feedback on how to adjust your training and sleep schedule to perform better. I've been working with Whoop on their scientific advisory council to help Whoop evolve their mission to improve the way that people are sleeping and thereby to improve their levels of focus, mood and alertness and performance in all endeavors during the day. As a Whoop user, I've experienced the health benefits, the focus benefits, essentially all of the major benefits that come with getting an excellent night's sleep on a consistent basis. I've also learned from using my Whoop how certain daily activities like the timing of exercise, caffeine, and a number of other things impact the depth, quality and duration of my sleep. Whoop is one of those tools that can really help guide you and provide you with personalized data, recommendations and coaching around your body and your overall health. So it's not just about tracking sleep, it's about tracking all aspects of your activity and health. And of course, including sleep. If you're interested in trying Whoop, you can go to join.whoop.com/hubermantoday and get your first month free. Let's talk about breathing. And of course we breathe in order to bring oxygen into the body, but we also breathe to remove certain things from our body, in particular carbon dioxide. So the main players in today's discussion are going to be oxygen and carbon dioxide. Now a common misconception is that oxygen is good and carbon dioxide is bad. That's simply not the case. Let's just take a step back from that statement and let's think about this. When we breathe in, we are largely breathing in air in order to bring oxygen into our body. And we can just stop right there and say, why do we breathe at all? Why can't we just get oxygen from the world around us? Well, it's because oxygen can't diffuse through our skin into the deeper cells of our body. Other single cell and very simple organisms can actually bring oxygen into their system without the need to breathe. But we have to breathe in order to bring oxygen to the cells that reside deep in our body. In particular, our brain cells, which are the most metabolically active cells in our body, require a lot of oxygen. And those brain cells are sitting, of course, in the brain, which is encased in the cranial vault, the skull. And so oxygens can't simply pass to those cells. So we need to have a system that will deliver oxygen to those cells. We also need a system, which turns out to be the breathing or respiratory system, that can offload or remove the gas that we call carbon dioxide. Not because carbon dioxide is bad, but because too much of it in our system is not good. In fact, much of today's discussion will also center around the common misconception that carbon dioxide is something that we want to get rid of. If you don't want to get rid of too much carbon dioxide, or else you can't actually get oxygen to the cells and tissues of your body in an efficient way. So you need oxygen and you need carbon dioxide in your body. You also need to be able to offload or remove carbon dioxide and bring in oxygen in the correct ratios so that you can perform the kind of mental functions and physical functions that you want to. So if we just dial out even further, we say, what are the key components of breathing? What are the elements within the body that allow us to bring oxygen to the tissues and cells as is required and remove carbon dioxide from the body as is required and yet keep enough carbon dioxide around in order to allow oxygen to do its thing. Well, that breathing or respiratory apparatus has two major components and I'm going to just briefly describe those. And as I do this, I really want to highlight the fact that anytime you're thinking about biology and physiology in particular, whether or not it's about the brain or the liver or the gut microbiome, it's useful to categorize things either as mechanical mechanisms or chemical mechanisms. What do I mean by that? Well, let's just take the analogy of hunger. There are mechanical mechanisms that tell us when we should eat. For instance, you have neurons, nerve cells in your gut that signal how stretched or non-stretched the walls of your stomach are, right? How full or how empty your gut is. And send that information to the brain to make you feel, to some extent, hungry or not hungry. In general, when our stomach is very full, especially if it's very distended, even with liquid, it suppresses our hunger. Whereas when our stomach is devoid of that mechanical pressure, especially for a number of hours, it tends to trigger hunger by signaling via neurons to the brain. In addition, there are chemical signals that go from the gut to the brain. For instance, we have neurons in our gut that can detect the presence of amino acids from proteins that we eat, fatty acids from the foods that we eat, the lipids and sugars, different forms of carbohydrate. The neurons in our gut are paying attention to or respond to how much amino acid, fatty acid and carbohydrate is in our gut and send signals to the brain to either stimulate or suppress hunger. So those are chemical signals that are being passed from gut to brain and they work in parallel with the mechanical signals. And this idea of in parallel with again is a very common theme in biology, especially neuroscience. The term parallel pathways refers to the fact that anytime there's a critical bodily function, it's very unlikely that just one type of information, like just mechanical information is going to be used. Almost always it's going to be mechanical and chemical information. I could pick a number of other examples. For instance, if you want to avoid damaging your skin or other tissues of your body, which is essential to life, well, then you have mechanical information about, for instance, whether or not something is pinching or ready to pierce your skin. That's mechanical information. It's sent via specific neurons up to the brain to signal a retraction reflex. If you move your limb away from wherever that intense pressure is coming. You also have chemical sensing in your skin, the presence of things that elicit a burn or that elicit itch or that elicit extreme cold. All of that chemical information is being signaled up to the brain as well in parallel. So parallel pathways is a common theme. So when we're thinking about the respiration, aka the breathing system, we also need to look at the mechanical system. What are the different components of the nose, the mouth, the lungs, et cetera, that allow oxygen to be brought in and carbon dioxide to be removed from the body, but not too much carbon dioxide removed, to allow breathing to work as efficiently and as optimally as possible. And then we also need to look at the chemical systems of the lungs, the bloodstream, and how different cells use oxygen and carbon dioxide in order to understand that as well. If you can understand the mechanical and chemical aspects of breathing, even just at a top contour, well then the various tools that I discussed during today's episode, such as the ability to calm yourself down most quickly by doing what's called a physiological sigh. I'll go into this in more detail in a little bit, but this is two very deep inhales through the nose. So the first one is a long inhale. And then the second one after that is a quick sharp inhale to maximally inflate your lungs, followed by a full exhale through the mouth to lungs completely empty. So it's big inhale through the nose, then short inhale through the nose immediately after that in order to maximally inflate the lungs. And then a long exhale through the mouth until your lungs are empty. You will understand why that particular pattern of breathing and not simply one inhale or not simply an inhale through the nose and an exhale through the nose as well is optimal for reducing your stress quickly. That double inhale through the nose followed by a long exhale through the mouth works to reduce your levels of stress and lower your levels of so-called autonomic arousal very fast in real time. And it works better than any other known approach. It's not a hack. This is actually something that your body has specific neural circuits to do. And it actually performs during sleep on a regular basis and even throughout the day. And that you can perform voluntarily. And it works so well to reduce stress very quickly, not because it brings in the maximum amount of oxygen and removes the maximum amount of carbon dioxide, but rather because it optimally balances oxygen and carbon dioxide. If you understand the mechanical and chemical aspects of breathing, then you will understand exactly why that particular pattern of breathing, the so-called physiological psi, is the most efficient way to rapidly reduce stress in real time. If you can understand the mechanical and chemical aspects of breathing, you will also understand why most people are over breathing, that is they're breathing too often, even if they're breathing in a shallow manner, they're breathing too often, and they are blowing off or removing too much carbon dioxide. And if you understand that carbon dioxide is critical for the way that oxygen is delivered from the bloodstream to the tissues of the body, including the brain, well, then it will make very good sense as to why people who are breathing too much don't actually experience all the effects of elevated oxygen, but rather they're putting their body into what's called a hypoxic state. They're not getting enough oxygen to the tissues of the body, in particular their brain. And this is true, not just for people who are obese or who suffer from sleep apnea, although that's certainly the case, but for people that have, believe it or not, certain personality types. We'll talk about breathing and personality type and actually how breathing has been shown to alter personality. That's right, breathing can alter personality in positive ways that allow anyone to show up to the various social and non-social endeavors of their life with more calm, more focus, alertness and improve their overall health. Okay, so let's talk about the mechanical components of breathing. It's really quite simple. You've got your nose, obviously, and you've got your mouth. And a little bit later, we'll talk about the incredible advantages of being a nasal breather most of the time, but also the incredible advantages of using your mouth to breathe both for inhales and exhales during particular types of endeavors. And we'll get back to that a little later. But for the meantime, the only two ways to bring air into your system are through your nose and through your mouth. We also have the larynx, which is a rigid tissue or pipe that brings the air from the nose and mouth down to the lungs. Now that word rigid is really important here because what we will soon learn is that your lungs basically act like a pump. You sort of know this already, but these are two big bags basically that can fill with air or that can squeeze air out. Now, what most people don't realize is that the lungs are not just two big bags of air. Your lungs are actually two big bags of air that inside of them have hundreds of millions of little sacks that are called the avioli of the lungs. And by having those hundreds of millions of little sacks, you increase the surface area of the lungs and by increasing the surface area, you allow more oxygen to pass from the air in your lungs into the bloodstream than if you didn't have those sacks. And you allow more carbon dioxide to move from the bloodstream into those sacks of the lungs. And then when you exhale, the carbon dioxide can be removed. Okay, so those little sacks we call avioli of the lungs are an important part of the mechanical aspect of breathing. We'll get to a little bit later. Okay, so at a first pass, the mechanical aspects of breathing are really straightforward, right? You can breathe through your nose, you can breathe through your mouth, goes down through the larynx. I told you the larynx is a rigid pipe. The lungs are not rigid. They can expand and they can contract like a pump to bring in air or to expel air. Keep in mind that the lungs do not have any muscles themselves. So we need muscles that can either squeeze the lungs or that will allow the lungs to expand. And there are two general groups of muscles that do that. And they are the diaphragm and the so-called intercostal muscles. The diaphragm is a thin muscle that sits below the lungs and above the liver. And when we inhale, provided that we are using what's called diaphragmatic breathing, that diaphragm contracts and when it contracts, it moves down, which allows more space for the lungs to inflate with air. Now the intercostal muscles are the muscles between our ribs. A number of people probably don't realize this, but your ribs of course are bone, but in between those bones, you have muscles. And the intercostal muscles, when you inhale, contract and that allows your rib cage to move up and to expand a bit. And I think, again, people probably don't realize that your ribs are not fixed in place. They can actually get further and closer apart from one another. So when you inhale, your rib cage actually moves up. Sometimes the shoulders will move up as well. And that's because those intercostal muscles are contracting. Now, muscles can't move on their own. They are controlled by nerves. So we've got the nose, the mouth, the larynx and the lungs. The lungs have all those little avioli in them. And as I told you, we've got the diaphragm as a muscle to move the lungs. And we have the intercostal muscles to move the ribs, which can allow the lungs to expand. Again, we're just on the mechanical components of breathing. But because muscles can't move themselves, you should be asking what moves the muscles. And it's really nerves that control muscles. So whether or not you're contracting your biceps or you're walking and you're contracting your quadriceps and your hamstrings and your calf muscles, it's neurons, nerve cells that control that. There's a specialized nerve called the phrenic nerve, P-H-R-E-N-I-C, phrenic nerve that comes out of the neck. And when I say it comes out of the neck, what I mean is that they're little neurons that reside in the brain stem, in the back of your brain, and they send little wires that we call axons down and out of the neck. They go close to the heart and a little bit behind it, and they go down and they form synapses. That is, they form connections with the diaphragm. And when those neurons release neurotransmitter, which are little chemicals, the diaphragm contracts and it moves down. So we say that the phrenic nerve is a motor nerve. It's designed to move muscle. However, the phrenic nerve, like a few other nerves in the body, is interesting in that it has not just motor nerves in there, neurons that control the contraction of muscles, it also can sense things. There has sensory neurons. So it also sends connections down to the diaphragm and actually down deep into the diaphragm and close to the liver. And note that I said liver twice now already, and we're going to get back to this later when we talk about physical movement and cramps of the body.