Andrew Huberman: The Real Reason You Can't Get Deep Sleep & Wake Up Exhausted

Here's the diabolical thing: the risk of dying early if you have bright nights goes up immensely. There have been a lot of studies on people using devices after 6 p.m. and getting artificial LED exposure — they live shorter lives, cancer rates go up, and they're metabolically unhealthy.

But here's the really scary thing: we have a generation of kids that are metabolically sick. They cling to their iPads and are constantly on devices. The problem is that most things are designed to make people do less of what's good for them, and we don't talk about this enough.

Andrew, you're one of the most trusted voices in health today, and we've waited many years for this — Protocols, an operating manual for the human body.

These 10 protocols are well established. They're the ones that will move the needle the most in terms of mental health, physical health, and performance.

Protocol number one: get sunlight. Daily exposure on the skin increases testosterone and estrogen in both women and men, and is important for libido. Second—and this is really key—is to reduce stress fast, which I'll explain how to do in a moment. Third, work out with weights for 45 minutes, taking your sets near to failure. This will triple or quadruple your cortisol levels. A lot of people have been told not to spike their cortisol because it's the stress hormone, but it's also a preparation hormone—you're preparing for adversity, but also for great things.

The next one is one of the most valuable skills: if you do it for 5 minutes per day, you will experience a significant improvement in mental and physical health. Then there's sleeping on your side, which is very important for offsetting dementia and getting rid of bags under your eyes. But Stephen, the number one thing you need to know about is the one where the moment I started, my life got so much better, and I really started to see what I could only describe as miracles.

Andrew, I have this outstanding question I have to ask you. You don't really talk in depth about supplements. — Oh, I do. I go ham. — So, you can only do five for the rest of your life. — Oh gosh. I highly recommend getting a...

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Andrew Huberman, we've waited many years for this, and now it has arrived: your long-awaited book Protocols: An Operating Manual for the Human Body. Inside, I counted roughly 50 different protocols split across seven areas — sleep, exercise, stress control, nutrition, light, focus, motivation and learning, and personal growth. You've written out 10 of the protocols you want to focus on sharing today. Why did you choose those 10?

They're the ones that are going to move the needle the most in terms of one's mental health, physical health, and "performance." Your life will be so much better if you do them.

Do they cost a lot of money to do, the 10 that you've picked?

No, they could be done either at completely zero cost or on an existing budget.

Do you do these 10 things every day?

Every day. There's one on there that I don't do every single day — I take off one day per week — but every single day without fail.

When you wrote them, did you write them in order of sequencing?

Yeah, throughout the day, from start to finish, because this is the other thing: protocols synergize. They ratchet together. How well you slept last night is dictating how well you feel now.

These are gears in a larger system — one moves, the other ones move. And while there is a place for pharmacology and supplements and things that you take, ultimately these gears fit together based on what you do.

The guest sketches a diagram of the daily cycle: waking up in the morning and going to sleep at night, with ten different protocols marked along the way rather than hours of the day.

The main line is the healthy cortisol curve. Most people don't realize that you wake up because of a rise in cortisol—it's literally called the cortisol awakening response. If you've ever woken up a minute before your alarm, it's because this response is heavily entrainable, meaning it can be matched to external stimuli. You want that cortisol peak as high as possible in the first 60 minutes of your day.

Everyone assumes you want low cortisol, but high cortisol early in the day is what provides elevated mood, focus, attention, and the ability to learn. It's also what establishes low cortisol in the afternoon and at night—which is a requirement for falling and staying asleep. The peak sets up the trough: high morning cortisol, low nighttime cortisol.

The other lines represent melatonin, the hormone of sleepiness, which stays low in the morning if you slept the night before, and the dashed line is adenosine, a downstream product of ATP use in your cells. The more you're awake, active, and thinking, the more adenosine builds up—that's why you get sleepy.

What's very interesting is that spiking your morning cortisol within the first hours of the day also establishes a pattern where the little blips—stressful texts, stressful events—are brief. We always hear that cortisol is bad, but the ability to have big inflections in cortisol that then come back down to normal is very good. If the morning peak is not high—if the curve is medium or what's called a "flattening" of the cortisol curve—you see shorter lifespan, less recovery from every kind of illness, and stress bouts that last a very long time because they're riding on a higher baseline. With a lower or flat morning cortisol, a stressful text during the day produces a longer, bigger cortisol spike.

There's also an indirect but important interaction between cortisol and melatonin: when the curve is flat, your sleepiness hormone doesn't come on and function as well, so sleep gets very disrupted.

A lot of people think they don't want their morning cortisol high, and women in particular have been told not to spike it because it will lead to excess visceral fat, moon face, and so on. That describes Cushing syndrome, a massive overproduction of cortisol—but it's a very rare condition. Most people's problem is the opposite: their morning cortisol is too low, and their afternoon and nighttime cortisol is too high.

"How do they know this stuff? How do they test this?"

The healthy cortisol curve was measured through consistent blood draws around the 24-hour cycle, and then studied in response to everything from caffeine to cold plunges to exercise to sunlight.

Protocol number one is hydrate. Your mind is exceedingly sharper when you're well hydrated, and it actually helps boost your morning cortisol. There's an interesting interaction between emptying the bladder—usually after people wake up and urinate—and then hydrating. There's an ascending pathway along the vagus nerve that serves to wake up the brain, and part of that has to do with hydration first thing in the morning. Conversely, you wake from bed to urinate in the middle of the night because of an arousal phenomenon involving hydration and a full bladder.

"When you say hydrate, do you mean electrolytes or just water?"

16 to 32 ounces of good clean water is fine. If you want to add electrolytes, great.

"How much is that? Is that a cup?"

This is 16 ounces, maybe 18—so a big mug. Over the whole day you want to consume about 80 ounces of water. It's a lot, but basically everything you want to do in the early part of the day you want to do more of, and less in the evening part of your day.

The next habit—and it could have gone first—is viewing sunlight, or 10,000 lux artificial light. I could spend three hours on this, but I'll keep it brief. When you view sunlight, it activates the melanopsin intrinsically photosensitive ganglion cells, which have been the major focus of my work for many years. These cells extend physical wires—axons—into your hypothalamus, where your master circadian clock resides, called the suprachiasmatic nucleus.

When you view low solar angle sunlight—sun low in the sky—there's an abundance of UV, though less than at midday, and you can look at the morning sun more easily than the overhead sun. The morning sun looks more yellow, orange, or even red compared to the overhead sky. The light coming from the sky is the same, but the specific wavelengths coming from the low sun are the optimal stimulus for these melanopsin cells that tell your central clock it's time to wake up—the day is beginning.

Something incredible happens if you get bright light in your eyes in the first 30 minutes—ideally, but even 60 minutes—of your day. Your brain's circadian clock wakes you up through two pathways. One sends signals through peptides and neural signals, activating what we call the HPA axis—hypothalamus, pituitary gland, which hangs outside the brain, and then the adrenals, where you release adrenaline. There's a unique window that passes about an hour after waking, during which your suprachiasmatic clock can trigger an alternate pathway that goes down your spinal column and triggers your adrenals to release additional cortisol. Viewing sunlight in the first hour of your day takes this peak. If you didn't view bright light in the first hour, the peak would come later, which is bad—your stress responses would then be bigger and longer.

This cortisol increase is driven by viewing sunlight. When I say sunlight, people—especially in the UK—say there's no sun where they live. This could easily be called daylight, because there's always daylight out. Even on an overcast December morning in the UK at 8:00 a.m., it's much brighter than at midnight. With overcast skies, less of the long-wavelength orange and red light comes through, but you still want daylight in your eyes in the first hours of your day. Go out on your balcony if that's all you can do; if you're in a car, roll down the window. It's not good to do this through a window or windshield.

There's so much data showing that spiking your morning cortisol this way establishes low cortisol and high sleepiness hormones at night, which buffers stress. It also kickstarts your immune system to protect you against bacteria and viruses you encounter during the day, and it's great for your metabolism, mood, ability to learn, and more. In the book I explain several ways this peak relates to the later trough, for those interested.

If you don't have access to sunlight or daylight, a 10,000 lux artificial light can be very beneficial. These lights have been shown to significantly offset the symptoms of seasonal affective disorder. But what we're finding from this huge UK Biobank study is that you want bright days and dark nights, and they're additive. Bright days significantly improve mental and physical health along a huge number of parameters. Even if you were in dim light all day, making it dark at night makes people healthier—the risk of dying early goes up immensely with bright nights, and we don't talk about this enough. If you wake up before the sun comes out and are up for two hours before sunrise, I highly recommend getting a 10,000 lux artificial light.

Last time we spoke, you took me outside after the conversation and had an app on your phone.

Light meter. I have no relation to the app, but I use it. It tells you how many lux of light you're getting at the moment.

It's additive, so one important note: if you miss a day, get outside for twice as long the next day. How long should you do it on a very clear morning with the sun rising? And by the way, you don't need to see the sun cross the horizon.

You don't need to watch the sun cross the horizon; you can simply wait until it's elevated but still low in the sky. People concerned about UV damage should know that when the sun is low, the UV index is much lower. This is due to a phenomenon called Rayleigh scattering. Sunrises and sunsets are colorful, while the sun overhead is hard to look at — a big, bright ball of light, because you're getting all the wavelengths, from UV out to infrared, at more or less equal intensities. When the sun is low in the sky, the UV isn't completely scattered, but much less of it reaches your eyes, so there's a much lower risk of sunburn and eye damage.

Here's the diabolical part: your screens are not nearly bright enough to kickstart the morning cortisol increase, but they are very capable of raising your cortisol levels at night, because that low level of cortisol makes you vulnerable to big increases. It's a detail I explain further in the book.

Is it just exposing my eyes to the light, or does my body need to be exposed to it? Great point. One of the protocols in the book—not one of the ten I listed—is about getting sunlight on as much of your skin as possible, as is socially appropriate. This comes from beautiful work in Glen Jeffery's lab at University College London.

They run a glucose tolerance test: they fast people, have them drink a glucose drink, and measure how fast blood sugar rises. If they shine red light—long wavelength light—on people's backs during the test, they observe a more than 25% reduction in the peak blood glucose, and they also look at the rate of rise. It's buffering the blood glucose rise, which we know is a good thing.

You can do this on bare skin or through a t-shirt, and people's metabolism rose significantly. Why? Long wavelength light can actually penetrate into and through your body—red light gets absorbed and reaches about 8 centimeters into the body, while infrared can pass all the way through, which this study shows beautifully. Along the way, it makes conformational changes in how your mitochondria handle electrons. This long wavelength infrared light from the sun—the heat you feel from the sun or from a long wavelength light device—allows your mitochondria to function more effectively and efficiently.

That's not to say short wavelength light—blues, greens, and ultraviolet—are bad. We need UV on our skin to make vitamin D. What you want is full-spectrum, balanced light, but not so much UV that you get a sunburn, and you don't want a lot of short wavelength light in the absence of long wavelength light. The best way to get that is sunlight in the early and later parts of the day, when the UV index is low and you're getting the full spectrum.

Indoor LED lights, which we all spend a lot of time under, may actually damage the mitochondria, according to evidence from Glen Jeffery's lab and others. Beyond the melatonin from the pineal gland that makes you sleepy at night, you also have melatonin in nearly all the cells of your body. There it doesn't make you sleepy—it serves as an antioxidant, but it's sort of captured, and the way to liberate it is through long wavelength light. So long wavelength light kicks on a protective mechanism against oxidative stress and damage to cells, with many positive effects.

Jeffery's lab has done experiments where people look at a long wavelength light for one to three minutes, a couple of times a week, across different ages and eye conditions. He's a serious vision scientist, not a biohacker, and has no interest in commercial products—although sometimes I wish he did. People over 40 who experience age-related vision loss (as we all do, a little) show improvements in vision from this simple practice.

Why? Your photoreceptors, which absorb light and convert it into the electrical signals that let you see, are the most mitochondria-rich and metabolically active cells in your entire body. Biologists love to play this game—someone claims the tongue is the most metabolically active, then someone else claims another tissue—but the photoreceptors, my friends, hold that title. They have a ton of mitochondria and need to protect themselves against the oxidative damage that comes with generating downstream products from ATP. Long wavelength light is what protects them.

So you can see significant vision improvements in people who view long wavelength light a couple of times a week—but only in people older than 40, and, get this, only in people who do it in the first three hours of their day.

Your eyes, body, and brain are not the same across the first third, middle third, and last third of your day, or at night. Your sensitivity to bright light's harmful effects after sundown increases—not immediately, but gradually. Meanwhile, your need for bright light in your eyes early in the day is immense; you need it and you want it. If you miss a day, get out the next day and view more light.

As for whether light on other parts of the body works: not for setting this system in motion. But it's a great idea to get out two to three times per week when the UV index is low—you can check it on your phone—generally in the early or later half of your day, and get some light onto your skin. You don't have to be naked or in a swimsuit; that's great if appropriate, but a t-shirt works too, because the long wavelength light will go all the way through. Glenn Jeffrey and Robert Roger Schwelt—a physician who speaks about the immense benefits of sunlight on the skin for recovering from disease and enhancing immune system function—support this.

When asked whether people should go out and buy a red light lamp, the answer is no — it's not necessary. Sunlight already contains everything you need. Pass sunlight through a prism, as on the Pink Floyd album cover, and it bends into a rainbow: red, orange, yellow, green, blue, indigo, violet. But sunlight also contains ultraviolet light, and some daily UVB exposure to the skin increases testosterone and estrogen in both women and men, which is important for libido. It actually reinforces romantic relationships for reasons beyond sexual interactions and attractiveness — the effects are strong. Sunlight has it all.

What you don't want is to go outside when there's so much UV that you get a sunburn, and you shouldn't think red light is the only light you need. You want that warmth from the sun.

And it gets better — "I'm selling nature," as the speaker puts it. When you go outside where there's a lot of greenery, the plants reflect long-wavelength red and infrared light. If you looked through infrared goggles, all that vegetation would be glowing white. Borrowing Roger's explanation: where's the coolest place to be on a hot day? Under a tree — because it's reflecting the heat, the infrared light. Out in greenery, you're getting all that long-wavelength light bouncing around and passing through you. So get out into nature and walk outside. If you work and live in a city, get outside and take off a brimmed hat, because you do want the sun getting down onto your face.

People are terrified of accelerating aging through UV exposure, but this isn't about baking yourself in UV light all day — the health benefits are immense. A Swedish study showed that the more sunlight people got, the longer they lived. In fact, smokers who got a lot of sunlight — not a favorite study, but it has to be acknowledged — lived longer than non-smokers who didn't get enough sunlight. There are other factors involved, like exercise, but the advice stands: don't smoke, and get sunlight.

There are a lot of night shift workers listening, and I have a section specifically for them, because the two scariest facts are these: night shift workers live shorter lives, cancer rates go up, and they are metabolically unhealthy. It's very hard to mitigate, but I provide tools specifically for night shift workers and for jet lag, since people travel.

Here's the really scary thing: you and I qualify as night shift workers. The studies on night shift work—barring the more extreme ones—were mostly on people who, after 6:00 p.m., are on devices getting artificial LED exposure, or doing activities besides eating, socializing with family, or being in bed. If you work at night at home, you're still a night shift worker; you don't have to work all night to count. So we have a generation of kids that are metabolically sick. I don't like to fearmonger, but there's something practical you can do.

Get late-day daylight to buffer screen light

As the sun goes down, you don't have to watch the sunset—though everyone loves sunsets—but try to get some daylight in your eyes in the late afternoon or evening. If you're working indoors from after lunch until nightfall, get near a window, go out on a balcony, or take a quick walk around the building—do what you can to get sunlight in your eyes without sunglasses.

If you get sunlight in your eyes in the last third of your day—the clock times don't matter, since we all get up and go to sleep at different times—you buffer the cells in your eye against the negative effects of artificial light at night. I call this your Netflix inoculation: you can be on your computer at 9 or 10 at night without it damaging your melatonin levels as much, and without it disrupting your blood glucose and your sleep.

But there's one population for whom this doesn't work, and it seems to be adolescents. You can't buffer them against the negative effects of screen light at night. What happens with screen light at night? Big bumps in cortisol. People say, "I can fall asleep just fine after being on my iPad." True—some people don't have as much of a negative effect from blue light at night—but the blood glucose effects and the next-morning cortisol effects are the problem. Remember, high cortisol sets you up for low cortisol, and low cortisol sets you up for high cortisol. So you've got kids whose cortisol is slightly but significantly higher in the evening and at night because they're on devices, and the next morning their cortisol levels struggle to get up.

This is a tough one, because teens socialize that way, and you don't want to take their phones away—they cling to their iPads the way my new bulldog Strummer clings to a chew toy: you can take it away, but they hate you for it. So my advice is to view daylight—you can't always see the sun, but even if it's overcast, just get out for a few minutes and take a walk. Your sleep will...

The speaker notes that the advice feels like giving a lecture in class, which the host welcomes. So far the routine covers hydration and sunlight. The third recommendation is one everyone has heard, but it matters: if you can exercise in the first three to four hours of your day, you could do it in the afternoon without a problem, yet there's a huge advantage to doing cardiovascular or resistance training in the first three hours of your day.

In the book, an entire chapter—chapter 2—is devoted to exercise, explaining what the author personally believes is the best way to structure a program for someone who doesn't want to be the most jacked, but wants muscle, definition and strength; someone who doesn't need to run a marathon at record pace, but wants endurance; someone who wants to sprint reasonably fast and has middle-distance ability too.

The structure: alternating lifting and cardio

The program is basically structured as lifting or cardio on alternating days, with three days total of lifting. You warm up reasonably, keep the volume of work sets low—two to three work sets per exercise—and emphasize compound movements. Not preacher curls or tricep kickbacks; those are fine, but you get far more bang for your buck from pull-ups, rows, dips—multiple joints moving at once—and some hip hinge movement, such as squats, hack squats, or deadlifts. The chapter also covers how to achieve specific aesthetic effects.

The author is by no means an exercise physiologist, but has been resistance training since age 16 and is now 50, turning 51 in a month, and feels great.

The cardio days

Do cardio at the start of the day, whether or not you're doing resistance training. The host warms up with 5 minutes of cardio and then resistance trains, but does the dedicated cardio on alternate days—three days total:

1. One long, slow session of about an hour.
2. One about 30 minutes at moderate intensity.
3. One short interval session, like the one done that morning: on the air bike, pedal easy for a minute, then go all out for 30 seconds, easy for 10, repeating 30/10 four times, then off the bike—basically max heart rate training.

And the day after leg day, if you do your legs right, take a rest day.

The speaker notes that deliberate cold exposure was conspicuously absent from the discussion of exercise. He then makes a strong claim: he will go toe-to-toe with anyone, online or off, that deliberate cold exposure does not raise cortisol — or at least not meaningfully. He finds it strange that the same people who recommend moderate to high-intensity exercise claim cold exposure raises cortisol, which he says is simply not true.

This holds for women as well as men. He addresses the question of whether his book covers both, explaining that he distinguishes between data when research shows sex differences, and acknowledges when no data exist in women. Here the data are clear in both sexes: only trivial increases in cortisol, but large increases in adrenaline, norepinephrine, and dopamine from deliberate cold exposure. Those catecholamines are valuable heading into your day, since they drive alertness and focus.

The stressor that appropriately raises cortisol — meaning the kind you want — is a psychological stressor, or physical exercise: 45 minutes of weight training with sets taken near failure, or a 30-minute run. If you exercise in the first three hours of your day, you get a big inflection in cortisol, which is desirable.

Some people can't or don't want to exercise first thing. Exercising later in the day is fine — cortisol will come back down. You can use long-exhale breathing to slow your heart rate (Andy Galpin discusses this), or take a hot shower, which paradoxically lowers your core body temperature and helps you sleep. When you heat the body's surface, the medial preoptic area in your brain acts as a thermostat: sensing a warm surface, it cools your core, and you fall asleep better. This is the same "socks on" or hot-bath effect, and a massage likely works similarly.

When you exercise early in the day for a few days — say twice — the next morning you wake up feeling more willing to exercise. Has your willpower changed? In some sense yes, but what actually changed is your cortisol entrainment. The suprachiasmatic nucleus clocks what you do all day: if you eat at 9, 12, snack at 3 and 6:30, you develop a food-anticipatory signal, with ghrelin secreted to make you hungry. We are clocks, and synchronizing them matters greatly. When you exercise at roughly the same time each morning, you'll have more energy in the 15 minutes beforehand — you start stirring around. Part of that is cognitive, but a lot of it is your brain anticipating that exercise is coming.

You reminded me of something I saw you talk about: the anterior mid-cingulate cortex, which I think you described as one of the most interesting discoveries in neuroscience.

It's not directly exposed here, but the anterior mid-cingulate cortex would sit somewhere around there in this brain model. It's an amazing structure. To remind people: when we feel some sort of pressure—social or physical—that we hate, and we decide to lean into it, to compete or push through that internal or external resistance, neurons in the anterior mid-cingulate cortex fire away. My colleague Joe Parvizi at Stanford, a neurosurgeon, showed that when this area is stimulated, people say they feel like a challenge is coming on and they want to lean into it. This is the brain area of tenacity.

Amazingly, it has connections all over the brain, including with reward systems, so it's collecting information about what's going on in the world when it gets activated—what makes you feel pressure, when you feel like pushing back and when you don't. But the best part is that it is highly subject to plasticity. People who diet successfully have an anterior mid-cingulate cortex that gets bigger and more active. The same goes for people who embark on a new exercise program—for me that's mobility work, since I've gotten a little stiff over the years. When you do something you don't want to do, that you don't do reflexively, your anterior mid-cingulate cortex gets bigger and more willing to engage in challenging things going forward.

That's the key point: it sets you up to do more challenging things in the future.

That's right. Why would you do deliberate cold exposure? Because your ability to sit calmly—or even not so calmly—when your system is flooded with adrenaline and norepinephrine carries over to your ability to keep your head straight when other things trigger adrenaline. You can trigger that state safely with cold water, like a cold shower or an ice bath, as long as it's not so cold that you're hyperventilating beforehand on purpose. You don't have ten stress systems; you have one. Stress means adrenaline goes up and comes down slowly, and cortisol goes up and comes down.

I came up with a model for arousal. People hear "arousal" and think of romantic arousal—it can be that, but arousal is really just how alert or sleepy you are. You can be extremely sleepy, as in a coma, or in full-blown panic. A seesaw is the right analogy here because of the autonomic nervous system, which is made up of two parts: the parasympathetic and sympathetic nervous systems. They sit in different parts of the body and both connect to nearly every organ. In general, when you're relaxed, that reflects parasympathetic tone going up; when you're stressed, it reflects sympathetic tone going up. As you get sleepy, your parasympathetic system starts to dominate, and dominates more the sleepier you get. When you wake up in the morning and do the right things—hydrate, get sunlight, get some exercise—your cortisol rises and you become more alert.

The ability to navigate stress of all kinds depends on what I call controlling the tightness of this hinge. When you train your ability to think, breathe, and stay calm while your system is flooded with adrenaline, then when something nonvoluntary happens later—something you didn't want to happen—your brain immediately goes to that trained place and you can maintain thoughtfulness. You know not to speak, which is often the best thing you can do, and you know whether to react or not.

Cold plunges illustrate this. One of the beautiful things about cold is that activity in the prefrontal cortex—the region involved in strategy and making meaning of what's happening—is greatly suppressed for the first 20 to 30 seconds. Know this about every stressful circumstance: in the first 20 to 30 seconds, you are, in effect, brain damaged. You're in a mode where you could react physically, which sometimes saves your life—step out of the way of the car, get away from the aggressor—but most times you're best off not saying a darn thing. Then your prefrontal cortex slowly comes back online, and then you're back again because you're ruminating.

This is good relationship advice. — Very good relationship advice. I wish I had learned it long ago.

Actually, last night I saw something on Twitter that was both perplexing and a little upsetting. I went to sleep thinking, "I know how to deal with this"—some long-exhale breathing, which slows your heart rate, and we'll talk about that. This morning it turned out to be a complete misunderstanding and everything was reversed. Last night I thought about sending a text, but I realized that late at night the prefrontal cortex is already diminished. This is why stress feels so much harder to deal with at night.

The prefrontal cortex and top-down inhibition

The prefrontal cortex is a big patch of real estate behind your forehead that is greatly expanded in humans compared to other mammals—I don't like calling them "lower," but they have less prefrontal cortex, so they're more driven by impulses. One of the most incredible things every child and adult needs to develop is top-down inhibition: you feel an impulse but resist it.

That's mostly how I trained my dog Strummer, because it works. At nine weeks of age I put down a piece of food—he loves food, of course he goes for it—and taught him "wait." He sits there and learns to look at me. Now I can have him moving toward food, say "wait," and with his nose inches away he'll just stop. He has great top-down inhibition. Is it about food? No. Am I torturing him? Of course not. It's so that when I say "wait," he can suppress his arousal.

This is one of the most valuable skills. People with frontal damage show an inability to do it, which is why they can sometimes be violent or say inappropriate things. When people are tired, stressed, or drunk, prefrontal cortex activity is suppressed. Get in a cold shower: the first 20 to 30 seconds are kind of fun—you're there with less of a brain than you had going in—and 30 seconds later you're thinking, "I can do this."

This explains why you do things tired. Don't do things tired. Don't say things tired. Impulse control is way worse.

The guest explained that hearing about the anterior midcingulate cortex — the part of the brain he described as a "tenacity muscle" — completely changed the host's relationship with hard things. It made him realize, on a conceptual level, that every hard thing he overcomes better equips him for harder things tomorrow, like curling weights in the gym. "I'm making a neurological investment in my future."

The guest agreed, noting that voluntary hard things can take many forms: cold plunges, learning a new language, learning to dance if that's stressful for you. It can be anything that creates internal resistance. This is a beautiful structure, because it's wired into cognitive capacities and our ability to build them, and connects to emotional challenges as well.

The host pushed back: aren't we optimizing our lives toward comfort? More comfortable things seems like a winning formula.

The guest pointed to Jack Dorsey, citing a small lecture available online where Dorsey said that anytime we exchange ourselves, our money, or our time for convenience, we are almost always giving up something fundamentally useful for us neurologically. It's okay to do — the guest orders food on DoorDash because there's great food and he doesn't have much time to cook, and would rather devote that time to other things. That's trading for convenience. But if you're aware of the trade-off, you're much better off. The real question is what you'll do with the additional time.

While he's against over-optimization to the point that it pulls you out of life and diminishes it, he's all for striving and optimization in ways that let you lean into the rest of your life with more vigor. He thinks Arthur Brooks says it best: we are wired for meaning to come from striving, and within striving is some struggle, and within struggle is also the release from struggle — which is itself very satisfying.

On over-optimization in a nutshell: there are people for whom doing two of the hard things he described for five minutes each per day will produce a significant improvement in mental and physical health. There are also "junkyard dog" types who can live on anything, with a ton of vigor, who say they didn't feel much from drinking some water and getting sunlight — people who can fall asleep in front of the screen, get up, and keep going on a sugary muffin. Fine. But everyone can afford to look at what they're doing now and try to move the needle toward more vigor, well-being, happiness, and peace by doing certain things.

Whether you become more sensitive to something when you stop doing it depends on the thing.

On nutrition, I cover everything from the all-meat diet to vegan diets, going into the literature so people can choose for themselves. But if you look at what most people could benefit from doing—and you could do this vegan or vegetarian, though it's a little harder—the best diet comes down to the following.

The core principles

Calories: not too many, not too few. That's individual, but it's easy to calculate, and I provide a way to do that.

High complete protein-to-calorie ratio proteins. This is a concept I came up with. Yes, we need the essential amino acids—that's what a complete protein is—but you can get that from beans and rice. The problem is that to get 30 grams of complete protein from beans and rice, you'll consume about four to five times as many calories as you would getting it from a chicken breast. It's an obvious factor that no one ever talks about. So eat eggs, lean meat, fish.

Fiber: vegetables and fruits. But I will say that many people who remove starches entirely—or remove vegetables entirely—find that their autoimmune issues resolve. There are reasons for that and we have to acknowledge it. Still, most people should be eating some vegetables and fruit for micronutrients and fiber.

Low-sugar fermented food. Justin Sonnenburg's work from Stanford is very clear: it lowers the inflammatome. In fact, when they had people eat more fiber, inflammatory markers went up for many people—no one likes to talk about that, especially not the vegans. Too much fiber can be noxious and pro-inflammatory for some people. Good options are sauerkraut, kimchi, beet kvass. The problem is they tend to be expensive, but you can make your own—there are recipes online.

Skip the seed oil debate

I don't want to get into the seed oil debate. Just use olive oil. It's delicious, and it's relatively inexpensive nowadays to get real olive oil. Small amounts of butter. Why are we even debating seed oils? The studies are not well done: you're comparing a processed food diet that includes seed oils against clean seed oils, or against a high-meat diet with processed meat. It's a mess. As a scientist, you look at this and go, this field sucks.

If someone wants a magnificent career in science, go into nutrition and do some really good studies, because about 90% of the existing studies are lousy. You don't even have to be trained in nutrition to see it—five different variables here, four over there. That's what you'd call a bad experiment.

The olive oil data, by contrast, are great—impressive. And then starches are great...

Starches are great for fueling muscles, glycogen and the brain, but you don't want to overdo them. The way people tend to overdo starches is by eating them combined with a lot of fats. Sourdough bread is great; sourdough bread with butter is even better, if you ask me. But sourdough bread with equal amounts of butter and bread — you're starting to get into problems. It's very hard for people to overeat starches unless they have a lot of fats or sugar with them.

Does eating starches late at night affect sleep? Many people who don't eat enough starches find that they have sleep issues, and there are reasons for this. We talk about comfort foods — typically people think of junk foods — but foods that increase glucose lower cortisol. That's weird, right? Starches lower cortisol, and you want your cortisol low at night, which helps you fall and stay asleep. You don't want to eat too close to bedtime, but you also don't want gnawing hunger at bedtime.

Here's the interesting thing: what is cortisol? Is it a stress hormone? No. It's a hormone that's released during stress, but cortisol's job is not to deal with stress — its job is to mobilize energy in the body. When cortisol goes up, glucose is mobilized, along with other fuels. So when you eat starches, you buffer cortisol. There's a very clear relationship here.

People who aren't eating enough starches and then allow themselves that bowl of rice or pasta in their final meal of the day, or a little at lunch and dinner, maybe even a bowl of oatmeal at breakfast, feel more even psychologically and have more physical energy. Sometimes people with chronic stress issues notice they stop shaking, and people with autoimmune issues sometimes see those resolve because their cortisol is buffered.

That's because your blood glucose is elevated, so your body isn't tapping into the survival system to try and mobilize glucose.

The interviewer raised a question about the earlier graph showing that high cortisol in the morning is a good thing: what if you pick up your phone first thing in the morning and read your worst emails? From the perspective of spiking cortisol, that's in some sense good — but does it matter how the cortisol comes, if you stress yourself out in the morning?

It doesn't matter. The problem is the rumination that comes with stress. Physical stressors we control, like a workout or a cold plunge, have an onset and an offset — though they start faster than they end, so stress carries over and you ruminate. Psychological stressors tend to bang around in our brain a lot, late at night, and tend to come back. He added that he thinks 2027 will be the year we close the coffin on this "cortisol is bad" idea.

Asked how to think about cortisol, given that most people see it as the stress hormone, the guest explained: cortisol is for mobilizing energy. If you're going to sleep at night, you don't need to mobilize energy — you need to rest and reset your body. Cortisol is an energy-promoting hormone. Before walking on stage in front of a big audience, his cortisol level goes up. If you're stressed about it, maybe a little more, but it's a preparation hormone: you're preparing for adversity, but also for great things.

He cited studies by James McGaugh and Larry Cahill showing that if you want somebody to learn something, spiking their cortisol before, during, or after that thing should work — trauma does exactly that, and you never forget it; all you can do is work on removing the emotional load of the traumatic memory.

The interviewer asked whether someone listening to the podcast in the gym would have better recall of the conversation than someone listening in bed. The guest pointed to a chapter of his book on learning, motivation, and plasticity. Exercise makes your brain better in at least two ways. First, it raises your levels of arousal: exercise doesn't make you smarter, it makes you more alert coming out of the exercise so you can go learn things — you have to be alert to learn, and in particular you need adrenaline and cortisol elevated to learn.

So while people say weightlifting and cardio are good for your brain, long slow cardio — his endurance friends won't like this — is not that great for your brain. It's not bad, just not that great. But an intense weightlifting session or a high-intensity interval training session primes you for learning in the 4 hours afterward, because you have a lot of stimulatory molecules in your body and can focus better.

Asked how a podcaster could sharpen real-time cognitive performance rather than just learning, the answer is that performance follows an inverted-U curve: if you're not alert enough, you can't do what you need to do, and if you're too alert, you can't either. You want to sit at the top of that U. Much of learning—and the work of the insular cortex—is about getting from "I don't want to do it" up to that peak. After that, it's usually about not getting too stressed.

That leads to the fifth tool, usable at any time of day: use the physiological sigh to reduce stress fast. Stress mitigation has two components, one of which is how to limit stress in the moment.

Why does that matter so much? Meditation, a good night's sleep, massage, social connection, being well-fed and hydrated all buffer stress. But when something happens and your heart rate is too high, or you're shaking and can't organize your thoughts, none of that helps—you've gone over the line, too far toward the alert end of the arousal spectrum.

Around 2016, the speaker decided to dedicate a significant portion of his lab to finding real-time stress mitigation tools. He started spending time with special operations people—though SEAL teams don't actually do ice baths; they spend a lot of training time in cold water—and with performance professionals, especially neurosurgeons who handle life-or-death situations for years while maintaining immense calm. One of them is his childhood friend Dr. Eddie Chang, chair of neurosurgery at UCSF, who has enabled people with locked-in syndrome to speak through a brain-computer interface and is also a bioengineer. The speaker visited Chang's lab and watched him remove a golf-ball-sized tumor from a patient's forebrain while the patient was awake. Eddie is the calmest person you'll ever meet, because a movement of less than a millimeter in the wrong direction could cost a patient's life. People like that have real-time ways to calm down.

So he teamed up with David Spiegel, then associate chair of psychiatry, who studies clinical hypnosis for smoking cessation, pain management, and anxiety. The study itself was mainly run by Malaise Yilz Balban in his lab, who built a stress lab using VR. About a hundred subjects wore trackers measuring heart rate, heart rate variability, and sleep, and were assigned to one of four groups:

1. Meditation for 5 minutes a day.
2. Box breathing—inhale, hold, exhale, hold—for 5 minutes.
3. Cyclic hyperventilation—big inhales, passive exhales, repeated for 5 minutes.
4. The physiological sigh—a double inhale followed by a long exhale, repeated.

How long should each phase last? There's a way to measure it: the carbon dioxide tolerance test. How well you can control an exhale tells you something about how stressed you are. When you're stressed, you tend to blow off carbon dioxide very quickly; when you're less stressed, long exhales become easier.

Cyclic hyperventilation is known by other names—Wim Hof breathing, tumo breathing, pranayama. It massively spikes adrenaline, which isn't a bad thing since you're controlling it, and incidentally does not spike cortisol much. Because those exhales blow off a lot of carbon dioxide, it shifts your internal state and tends to make people very alert.

The fourth condition was the physiological sigh. Jack Feldman at UCLA and others, with observations going back to the 1930s, had noticed that animals and people do this strange breathing pattern when very relaxed: a double inhale, then a long exhale.

Jack's lab discovered a brain area called the parafacial nucleus, which exists specifically to generate this double-inhale, exhale pattern in animals and in humans. Nature doesn't make mistakes like that. It turns out there are two breathing centers. One is the pre-Bötzinger complex—named after a bottle of wine—which handles the ordinary alternating pattern of inhale and exhale. The other, the parafacial nucleus, which we all have, is involved whenever you double up the inhales or exhales, and in breathing while you speak, sing, or eat.

It generates these physiological sighs, which get triggered when there isn't enough oxygen, when you feel claustrophobic, or when you're very stressed and carbon dioxide rises. Your brain senses that and triggers the gasp reflex. The double inhale maximally inflates the hundreds of millions of little sacs in the lungs, and then the exhale offloads the greatest amount of carbon dioxide. A single breath doesn't offload as much CO₂, but with a second short inhale, those little sacs in your lungs—like balloons at a kid's party, empty but fluid-lined, with surface tension making them stick together—get opened up by the double inhale, and then you offload the carbon dioxide.

That's great, but the real magic of deliberate...

The real magic of deliberate long exhales is that they slow your heart rate down through a process called respiratory sinus arrhythmia. This is the most important thing for anyone interested in stress, exercise, sleep, and wellness, because we have this vagus nerve—everyone likes to talk about the vagus nerve. It's a massive nerve bundle that collects sensory and chemical information from the organs of the body and sends it up to the brain, and it's classified as parasympathetic, calming. But here's the funny thing: when neuroscientists want to wake a person up during an experiment, like a neurosurgery experiment, they stimulate the vagus. A treatment for depression is to stimulate the vagus. Guess what that does? It makes people more alert. So it's a mixed nerve.

The really cool part about the vagus is that it's not all ascending. About 85% of the information goes up from the body through the vagus, but there's another pathway that goes down to your heart and controls the slowing of the heart rate when you exhale. Heart rate variability is the slowing of your heart rate when you exhale.

You want to increase your HRV? Do a few deliberate exhales during the day. People ask, "How do I get my HRV up?" Well, yes, you can do VO2 max training, max heart rate training, HIIT workouts, and so on. But if you really want to increase your HRV in sleep and while waking, just do some deliberate exhales during the day, because that's the parasympathetic, calming arm of the vagus pushing down on your heart rate. All of the groups I described saw benefits, but it was the people who did these physiological sighs that benefited the most.

I then started exploring how fast heart rate slows down with a physiological sigh, and it turns out you don't need to do it for five minutes. Do it once. If you're feeling stressed, going on stage, waiting for a diagnosis, or simply too alert relative to how you want to feel—for whatever reason, good or bad, like you're about to get married—you just do the double inhale and exhale until your lungs are empty, and the effect is immediate.

For me, that was immensely gratifying. It's fun to publish papers—Melissa gets the lion's share of the credit for that one; there were other people on the paper, but she did so much of the hard work and analysis—but I was gratified because finally, if I didn't sleep well, or if something stressful happened even though I slept well, I can calm myself down just like that. Real-time tools for stress are what we all need.

The interesting thing is that you can also raise your stress threshold—a lot of the stress mitigation chapter is about how to do that. We need to train for discomfort so that the little things don't feel so big. This matters in survival situations too, where you need to think very clearly about what order of operations to take and what direction to escape through. This is not about setting yourself up to tolerate more pain and abuse; it's the exact opposite. It's about safety and self-protection, and about noticing when we're alert but calm. In that state, we can notice the subtle ripples in the people around us—who needs our attention, who we really don't like but never really realized it. You can notice that stuff.

A lot of people wake up at 2 or 3 a.m. and don't really know why. They don't know how to get back to sleep, and they start worrying and ruminating.

That's very common. In that moment, you can use a tool: ten long, deliberate exhales. There's also a really crazy trick I put in the book that has indirect scientific support.

Why eye movements affect body awareness

To fall asleep or fall back asleep, you need to stop thinking about your body position. There's a dedicated circuit between your eyes, their movements, and your cerebellum, which is involved in proprioception, balance, and other things. We call the cerebellum the "mini brain"—it's the highly folded structure at the back of the head ("folia" are just folds). It's involved in balance and learning, and it's very important for generating and responding to the error signals between what you're trying to do and what you can do. That error signal, generated through genuine attempts, is one of the most important drivers of learning, and the cerebellum is critical for it. It's also involved in timing.

So you need to turn off your recognition of your own limbs to fall asleep. How do you do that? Think about what works with babies: walking back and forth at a particular pace while gently swinging them. A Japanese study defined this—parents figure out the exact cadence, with a very small margin of error, through trial and error to get their kid to sleep. It's like a natural experiment, and it's been examined in the lab.

When you rock back and forth, your eyes move. This is a very ancient system that exists in all jawed animals, including us: as we move through space—walking, running, swimming—the world glides by, what we call optic flow. You would see the world as blurry, but a compensatory eye movement, driven by connections between your eyes, brain stem areas, and your cerebellum, creates a visual slip error and your eyes automatically offset it. So when I move like this, the world seems stable.

It turns out there's a pattern of eye movement that can shut down the proprioceptive circuits in the cerebellum, make you forget your limb position, and greatly speed up falling back asleep.

The technique

Close your eyes, then:

1. Move your eyes slowly to one side under your eyelids, then to the other side.
2. Then up, then down.
3. Move them counterclockwise in a circle-ish motion, then clockwise.
4. Still with eyes closed, point them toward your nostrils—without crossing your eyes—and do a long exhale.

Doing that two or three times generally has people waking up the next morning wondering what happened. What happened is that your proprioceptive circuits shut down. It costs nothing and generally works, though if you're really, really stressed, it might not. This is what I do if I wake up in the middle of the night: I go to the bathroom, get back in bed, do long exhale breathing, do the eye movements, and wake up the next morning. It works really well.

A sleep mask built on this science

It works so well, in fact, that there's a company based on work by two MIT scientists. They make a sleep mask that generates this pattern of eye movements through a small electrode behind the ear, stimulating the extraocular muscles in just the right patterns. I tried it, and you fall right asleep.

And it monitors REM directly—not like an Eight Sleep or Whoop, which infer REM from changes in heart rate and breathing, but direct monitoring. It can also control your eye movements to induce more REM if you want it.

Within the next 12 to 14 months, because of devices like this, you'll be able to say, "I want 2 hours of deep sleep and 2 hours of REM across a 6-hour night, because I can't afford my full ration of eight." You'll be generating those eye movements during sleep to facilitate—not force—those sleep patterns.

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Yes, there's a peptide that can help your REM sleep — it's called pinealon, and I have no affiliation with it. I should say that in the book I don't talk about hormone therapies, peptides, or psychedelics; the book is about what I know for sure. Hormones, peptide therapies, and psychedelics are at the front edge right now. I'm very much involved in looking at the research and talking to the people doing these things, and yes, I dabble in them — I'm very interested, I experiment on myself, and I'm an adult, so I can do that.

Pinealon is very interesting because I found that if I took an itty-bitty bit every third night — I tried this experiment for about a month — I got massive amounts of REM sleep that night, and also on subsequent nights. I hosted Dr. Abud Bakri on my podcast; in my view he's the most knowledgeable physician on the topic of peptides.

Oh, I saw that episode. It's amazing.

He's amazing, and I think you guys would have an even better conversation, frankly. In any event, he tells me that pinealon is potentially involved — there are some data supporting its use for encouraging pineal health, meaning the actual health of the pineal gland.

Right — the pineal gland, which makes melatonin and does other things too. So I think pinealon is a great tool to use sporadically. I don't use it

As long as we're talking about peptides, I'd say I'm "peptide curious" — I'm from the Bay Area, so that's the joke. I haven't tried any GLPs yet, but I'm getting curious about very low-dose tirzepatide or retatrutide.

I'm peptide curious, but I'm scared — mostly because you have to inject most of them, right?

What's your take on peptides as a category? It's a big category — everything seems to be a peptide these days.

Here's my opinion, and it will be popular with some people and unpopular with others: as with hormone therapies, supplements, or anything else, you need the fundamentals — sleep, hydration, sunlight, exercise, nutrition. The behavioral tools are the foundation. Great things can happen when you build on a foundation. Things can happen when you build without one, but it doesn't last long. The combination of the two can be pretty awesome, especially for someone with the means and the interest.

GLP drugs and retatrutide

The GLPs are the weight loss drugs. I think retatrutide is amazing. It's not just a GLP — it also hits the glucagon and GIP pathways. Eli Lilly invested hundreds of millions of dollars, if not more, into researching it, and it went through phase three trials. People lost approximately one-third of their body weight in about a year.

Is that a good thing for everybody?

No. What's happening now is that the psychedelic community's idea of microdosing has been incorporated into GLP use — people realized they could bypass a lot of the side effects and the cost by microdosing GLPs. These are anecdotes, so I want to be clear: I'm not pushing peptides or selling peptides.

I have a friend who is very skeptical of anything not fully FDA approved — "I don't want to hear about your biohacking nonsense" — but she has chronic fatigue syndrome. She asked me what she could do, and she has seen many physicians, including at Stanford and UCSF. She's a very smart, nuanced person, but she's hit a wall. She started taking a very, very low dose of tirzepatide once every 10 days.

And tirzepatide is...?

It's one of the GLP drugs. We could talk about semaglutide, but it doesn't touch GIP or glucagon — it mainly just increases levels of glucagon-like peptide, which suppresses hunger and appetite but also seems to lower inflammation. Yes, there are concerns about vision loss in people with certain structural abnormalities of the eye. Yes, there are concerns about apathy if people take too much. It seems to reduce alcohol craving for people who like alcohol, and sugar craving more generally — and it can reduce craving for everything if you take enough of it.

How GLP-1 was discovered

Keep in mind these drugs ramp up GLP levels a thousandfold or more. The body has never seen this level of glucagon-like peptide in the history of humans. The whole thing was discovered because a smart biologist was studying why Gila monsters — reptiles I think are ugly, though he probably thinks they're beautiful — only have to eat a couple of times a year. It's because they make a peptide called exendin, which turns out to be homologous to glucagon-like peptide-1 in humans. These reptiles don't have to eat often because they always feel satiated, thanks to very high circulating levels of glucagon-like peptide. We don't have that.

It works through two mechanisms: it tells the brain's satiety mechanisms to ramp up their activity, so your brain tells you it doesn't really want food, and it also makes people feel full — which is the basis of some of the side effects like nausea.

My friend will tell you, "Oh my god, my energy's back, my inflammation markers are way lower. I'm not cured, but I feel so much better." It's very hard to dispute that kind of experience if you're the patient. We could talk about safety and sourcing and so on, but people are starting to realize they can microdose these things. You won't see randomized controlled trials pushing this notion — it's terrible for business.

Peptides and GLP-1 Concerns

There are peptides like pinealon for sleep, and epithalon perhaps for DNA repair, though I haven't dabbled with that one. Then there are the so-called growth hormone secretagogues—tesamorelin, ipamorelin, CJC-1295. These promote more growth hormone release and sleep, but they have a negative feedback effect, shutting down some of your own production. People get a bit leaner, claim their deep sleep is better, and it can increase insulin sensitivity.

I've tried sermorelin and a few of the others—they nuked my REM sleep and gave me a ton of deep sleep, and I didn't like them. I've tried pinealon and still take it now and again, though not currently. BPC-157 is the one that gets everybody talking because body protection compound 157 is made in the gut. People claim—and I do think their claims are accurate, notice how I put it—that they feel as if their recovery from injury was accelerated. I believe them, because I've spent a lot of time with the animal data: whether it's Achilles tendon transection, nerve regrowth, tendon or ligament regrowth, or vascular healing, it does seem to accelerate healing across the board. But the concern is that you could vascularize tumors.

Would I take it? No—I don't have an injury, so I have no reason to. The right question isn't "should I take peptides?" but "what effect in your life are you trying to achieve?" Then maybe BPC makes sense, maybe it doesn't. You won't find many clinical trials on it, and it has a very high—maybe infinite—LD50, meaning no one has figured out how much can kill you. But that's not a good way to run your life. It's somewhere between a drug and a supplement.

One conversation I often hear around GLP-1s is that they haven't been around long enough for us to know the long-term side effect profile. Is there any truth to that?

Well, do you want to be in the experimental group or the control group? For somebody with serious obesity issues, the tirzepatides and semaglutides—Ozempic, retatrutide—could potentially save their life. Vision loss is a serious consideration, though I'll go on record here. Vision is my home, and I don't tap dance: David Sinclair recently went on Rogan and said the amount of blindness caused by GLP-1s has doubled, which scared everybody.

But there's a structural abnormality in the eye of a subset of people for whom that's true, and it's a great idea to get your eyes scanned.

Here's how vision works: light comes in through the cornea, and the lens focuses it onto the retina, this pie-crust-like structure lining the back of the eye. It's amazing—three cell layers thick, it absorbs light, and the photoreceptors turn it into electricity through phototransduction. That electricity is cast forward to cells lining the inner retina called retinal ganglion cells, which send their axons out the optic nerve into the brain, coursing along the bottom of the brain and into structures including your circadian clock. You get vision, sleep-wake rhythms, hormone regulation by light—incredible.

Where these wires exit the eye is called the optic nerve head. If it's a nicely shaped and sized tube for them to exit, great. Too big isn't good, but too tight isn't either, because the wires get pinched off. That's part of what happens in glaucoma: eye pressure goes up, those axons and cells die away, and it's the second leading cause of blindness in the world. So in some people with a structural feature of the optic nerve head, it does seem GLP-1s put them at greater risk of some cinching off of those cells, and there have been cases of blindness.

But here's what wasn't cool about what David did: he is developing potentially impressive tools to rescue vision in glaucoma, yet GLP-1s are not making many people go blind. That claim is about as true as masturbation making people go blind. I'm not saying you should do either one—that's your personal choice—but he scared the daylights out of people, pun intended.

Everyone should get this area of the eye imaged, and it's easy: go to your ophthalmologist or optometrist and ask for an eye pressure test. Insurance usually covers it, and it's definitely worth paying for.

The conversation turned to psychedelics. One speaker noted he doesn't discuss his own psychedelic use publicly, but the other admitted he's open-minded: he took DMT "in a far away land where it was very legal," and had also worked at a psychedelics company for about a year. What drew him in was the efficacy for mental health and the clinical studies coming out of London on psilocybin, ibogaine, and DMT treatments. The clinical data seemed unbelievable, so he wanted to learn more firsthand — he did psilocybin, then DMT.

The other speaker said he hasn't tried DMT, but has done clinical MDMA and psilocybin. He thinks he's done with that — not because of a negative experience, but because he got what he wanted out of it and found it immensely beneficial, especially combined with therapy going in, during, and coming out of the experience.

The DMT experience prompted deep reflection on religion. What he experienced felt indistinguishable from ordinary reality in its vividness and realness, and he pondered how a tiny inhale of smoke could completely change his material reality. He concluded that material reality is, quite literally, just a small amount of chemicals being uninterrupted — and asked whether that logic makes sense.

The neuroscientist responded that he thinks about this a lot, and offered a few non-dismissive ways to frame it. Most of biology is compartmentalized chemistry: whether it's the flow of electricity along neural circuits generating tenacity or learning, you're just guiding chemistry in particular ways. That's not meant to trivialize it, just a way to think about it. There are only two ways to change brain function, behavior, and chemistry: mechanical forces — breathing differently, getting a massage, poking yourself with a knife — and chemical forces, from pharmacology, things we eat, and chemicals within us like serotonin. There's nothing else. So yes, in many ways the logic holds: it's compartmentalized chemistry, and mechanics and other chemicals control that chemistry. Organizing thoughts this way can be helpful — you realize the stress response is really just a bunch of chemicals happening in certain places.

Personally, he's intrigued by the idea of things outside our conscious understanding in biology — things that DMT, or perhaps prayer or faith, might give us access to. This comes from his recognition, both as a neuroscientist and as a human who's been alive for fifty years and some change, that our biology and psychology are extraordinarily good at accomplishing certain things, but there are certain things outside their abilities. If we ask our psychology and biology to satisfy something they simply cannot satisfy, we miss out on a lot of potential meaning in life. To be very direct: that's the point where he decided to embrace the idea of faith in a god — that there are powers outside of human understanding that can be very useful.

Everything got better. It relieved me of the pressure to control everything, internally and externally. And I find it not just intriguing, but absolutely captivating that a force outside of us—some people call it God, some call it the universe, some might think it's Jesus, some might think it's something else—might actually hold some power in how we could potentially behave and be better.

Wouldn't it be wonderful if there's this thing planted in us, or in some of us—which is itself a question—about things outside of us, that if we were to embrace it could allow us to get to a better place as a species? Why would we think that a technology like AI would do that? AI is wonderful, but why would we think it would come from computers? That's of us. Why would we think it would come from anything that humans, and only humans, could do?

To me, embracing the notion of a God and having faith—which, by the way, is about having doubt but still doing the practices, like prayer—is one of the most liberating and educating things, not just about God and the universe, but about the human brain.

"I've got some questions."

"Yeah, I mean, it's like we're not meant to solve this on our own."

"Do you believe in God?" "Absolutely."

When asked when God came into his life, he said it was very early, but he was good at suppressing the notion that it was real—he would pray in private and hide it, and not just in bad times. Then, after living long enough and observing enough hardship, both in his own life and out in the world, he began to realize something else was there—especially, he says, if you stick your hands in enough brains. He describes watching his good friend Eddie Chang record from the brain of an awake human, remove a tumor, and save that person's life, and seeing that brain areas control things because when they're stimulated, the person feels and responds in a certain way. "You realize that we're not all meat and potatoes in there. There's something else." But he's not sure that it all comes from us, and admits it's hard to explain.

His father's lesson: faith and quantum mechanics

The best way he can explain his position is through a conversation with his father, a theoretical physicist he brought on his podcast. They had a choppy relationship for many years but are close now; his father is 83, super vigorous, loves ideas, and is into quantum computing. He asked his father to explain quantum mechanics and chaos theory for his audience, and his father agreed on one condition: you have to understand that early on you learn that the human brain can't wrap its head around quantum mechanics with logic or human understanding—you have to rely on the math. Anyone who talks about the quantum field without being able to show you the math and the proofs is lying. His father loves mocking how people in meditative communities and elsewhere throw the word "quantum" around, because very few actually understand quantum biology, and there are gaps in their logic that the math doesn't line up with. "And the math doesn't lie."

Applied to God, his father's point was this: at some point, if you're going to have faith in a higher power, you have to depart from the notion that your logical brain can go from A to B to C and boom, you're there. In quantum mechanics it's the same thing—except that on the basis of quantum mechanics you can build and engineer things in the real world, like a red light or a rocket.

There's no math to prove this thing that I call the existence of God. There's no math, and it's not worth torturing yourself over. What I believe is worth torturing yourself over.

Prayer, peace, and "miracles"

He also sees great beauty in embracing the practice of prayer and the questions—opening the aperture of your beliefs just for a moment, going, "Maybe I'm going to just believe in God for 10 seconds" and seeing what that's like. He started to experience beauty and peace around not trying to control things that were obviously not under his control, not just within himself but in other people. He began to see what he could only describe as miracles: he would pray for some indication of the right path on something unclear to him, and two or three days later something almost completely unrelated would happen, and the answer would come in that thing.

That's when he locked in. "I'm a disciplined guy when I really want to be. I'm going to pray every night before I go to sleep. If I fall asleep, I'll get out of bed and pray when I wake up in the middle of the night." He has not missed a night in nearly three years.

He was recently invited to Stanford to give a talk with Arthur Brooks, a lifetime Catholic who is at mass every morning. He and Brooks have very different experiences of God and religion—his own family was mixed religion.

When I sat up there, I just said, "Listen, I'm for sure the person who's least knowledgeable, least versed in this room. But what I can tell you is my experience with prayer—what I've observed in myself when I open the aperture for faith."

The reason I gave that talk is that our former director of neurosciences at Stanford had written to me and said he thought I should speak to this group. He did some of the most important experiments in the history of neuroscience linking neuronal activity to perception. He really showed that if you stimulate certain brain areas, people perceive things a certain way regardless of what's happening in the world. There's a brain area I could trigger right now and show you a movie of a bunch of dots moving up, and everyone here would say, "They're moving up." If I tickled the right neuron in your brain, you'd say, "They're going down." That's wild. Then I turn it off and you say, "Oh yeah, of course they're going up."

Your understanding of the world is an abstraction that occurs inside your skull, on the basis of photons coming in through your eyes, sound waves hitting your ears, mechanical forces hitting your skin, and chemicals entering your nostrils and mouth. You abstract reality in here. The laws of physics dictate the properties of those photons and sound waves, and they're transformed into signals. But then you abstract the world with enough accuracy that I can pick up this pen and not miss it—at least for now.

If you understand neuroscience that way, then consider: we don't see infrared in this room because we don't have the sensors, but a pit viper does. Does that mean there's a God? No, not necessarily—that alone doesn't prove it. But what it does show is that we only have access to the physical events in the world for which we have the internal filters to extract them. That's a mealymouthed way of saying you can't see it because you can't see it—you don't have the sensors. You can throw on infrared goggles and then you can see it, but that's technology.

I don't think there will ever be "God goggles." The emotional goggles, so to speak, come from what we call faith. Faith is the infrared goggles of human understanding about why we're here. The challenge, I feel, is that people come in at least three categories. Either they were force-fed religion in a bad way so they hate it; or they never had access to it in a way that gently pulled them toward it—it felt like people knocking on their door, a disturbance. I'm not against proselytizing if it's done kindly and delicately. Or they are absolutely convinced it can't be true, which I look at as a kind of spiritual anorexia.

There are regions of the brain that, when stimulated, give people an experience of God—not as themselves, but they feel it. So people have said, "Well then, there's a God region of the brain, and it's just a brain region—that can't be." But we have brain regions for everything. Arthur says this much more eloquently than I could: there are brain regions for thirst, and philosophically—this is coming from him, not me—you could say that thirst proves the existence of water. So I have a thirst circuit for gaining understanding of this thing we call life and whatever comes after it. In that thirst, I decided to open the aperture to the idea that the thing—the stimulus, the water, the photons—is something I'm not able to extract through thought, through my eyes, through my ears. Just like my dad couldn't come to understand quantum mechanics by thinking really hard about it—you have to do the math. There are gaps in my reasoning here; it's not a perfect one-to-one. But also, life's just so much better, man.

I don't think anxiety sticks in us very long. If we're feeling anxious, we pray: "God, please help me remove this." It's not "do this for me"—it's "help me put energy in me to do the right things today, put energy in me to serve people." I prayed before I came in here. I get on my knees before every podcast guest or host and pray. I just said, "Please help me move my ego out of the room. We all have an ego."

Help me move my ego out of the room. I would hope that people could learn useful information that might help them, and that they would propagate that information. Please make sure that I maintain humility, help me strive for clarity — and I also said, help Stephen and me do something that we're not predicting, that would happen but you want to happen, that we don't understand. Maybe that's this part of the conversation, right? I don't know. And the point is not to know.

It's also fun. As a scientist who loves mechanisms and cells and circuits and neuromodulators, it's enriching to have a part of life that I can just explore. I like mysteries — science is about mysteries and about solving them, but it's also about being in awe of the mystery.

I'm all in, man. I mean, I'm a different kind of all-in than other people talk about being all-in. I don't tell people what to do morally; I'm really just trying to navigate my own path. But it's one of the best things that ever happened to me. It's so liberating, and life is still plenty hard — but I love it.

The interviewer suggested that religion seems to be an antidote many people are reaching for now, given how we've designed our lives over the last couple of decades: the individualism, the loneliness, the nihilism, the me-me mentality, material success, and the low-level narcissism of being on social media chasing followers. We've become islands. He had been thinking a lot about God and meaning, because it appears we are meant to be anchored — to ourselves, our family, our community, maybe our city, our country, the planet, and then something above.

"You're an ambitious guy. Go bigger, man." The guest took the point: the biggest thing is a nonhuman force in the universe that wants goodness and can exemplify perfection. By virtue of being human — by having the circuits we have — we're wired with an animal part of the brain and a conscious, thoughtful part. He joked about the famous brain-stimulation studies: the area people most like to stimulate is the one generating frustration and anger, which he found disappointing — why not beauty or giddiness? (They found those too, but people weren't as interested.) Are we bad? No. But ascending — living in a controlled, thoughtful, peaceful way with yourself and your pursuits, striving to put goodness in the world and take care of people with less friction — is a lot of work. From experience, that reduced friction comes from trying not to control every aspect of every process; somehow everything then goes much better.

People might say he drank the Kool-Aid, but he believes this was pumping in his veins from the start. Yes, he studied stress, vision, and neural development — sperm meets egg, cells divide, you get a human; we understand induction factors, cell migration, axon guidance, mesoderm and ectoderm. Compartmentalized chemistry can give you a human, but there are gaps in our understanding, and there's magic in that orchestration that goes beyond what science can even begin to grasp. It's nothing short of spectacular. And who doesn't want more awe in their life? Dr. Keltner, the awe researcher at Berkeley, describes awe as the transition from small aperture to big aperture — and you can hear it in sound too. Walk into Stanford's Memorial Church with its giant organ and people change. Of course humans made it, but it's a shift from day aperture to holy aperture. You can get this other ways, he acknowledged, but he likes the idea that if we dial out really far, there's something much greater than us. He doesn't know what form it takes or how God would exert influence over our minds.

"You don't need to." That's the thing he has to come to terms with: this is really interesting, with lots of meaning and benefits for his life — but then he asks, which Bible do I have to believe? He starts looking at the Bibles and thinks, "Okay, Noah's ark."

"Look at a bunch of them. I think one will call to you more than the others. It may end up being atheism for some people. But when I said spiritual anorexia earlier — anorexia is the most deadly of the psychiatric illnesses."

Anorexia is incredibly deadly. Something happens to the neural circuits so that people with true anorexia feel a kind of reinforcement—almost better than reward—from avoiding food rather than eating it. That runs against our evolution as a species and against our health. But the desire for food, as Arthur would say, proves the existence of food; the desire for thirst proves the existence of water. Some atheists say, "Yeah, I don't need it, not for me." But there are other atheists who have a kind of spiritual anorexia—their spirituality is not believing in a god. Looking at them, I think they're on the same extreme: it wraps around so far that the truly religious people and the atheists meet right here. They both have the same sort of thing, just with an inversion of the circuit. I don't know whether someone will work out the neuroscience or not. I'm going to keep praying, because my life is that much better.

When I heard you talk about it, I started praying a little bit—not all the time, but there were several moments where I thought, now would be a good time to just pray. Someone like you saying that you do it gives a lot of other people permission to try and to investigate for themselves. If I'm in the human camp, maybe I'm someone who really cares about scientific rigor and precision—and if that camp can also be open-minded to spirituality and religion, I can still be ideologically who I believe I am while investigating these other things. So it was really impactful to hear you talk about prayer. It gave me permission, at some weird level, to investigate, and I report the same findings as you: it helps.

My former chair and director of neurosciences at Stanford, who encouraged me to give that talk at Veritas—where I mostly talked about how ignorant and naive I am on these topics—is a brilliant neuroscientist who has faith. I respect him and I respect his mind.

There's maybe a fun analogy here. It happens in every dimension—audiences and podcasters, or the health community during the pandemic, whose long tale we're seeing now. When you're a kid, you think your parents are everything, that they can do no wrong. Then comes adolescence: you catch them lying or saying things, and suddenly you decide they don't know anything. Then you gain some agency and philosophy in life, and you reach the point where you think you know everything and accept that they don't—but you're really the one who understands. As adults, we eventually get past that place and go, "Wait, it's outside of me. I've got to look outside of me." Then you realize all these adults went through it too, and we went through it. The real move is going, "Wait—I'm looking at humans for something that isn't going to come from human beings. We're all flawed, all imperfect." So the belief that perfection exists outside us, and that we can strive for certain things through works and practices—that's not just compelling, it's downright fantastic to me, because in embracing God you fully embrace both the woes and the beauty of being human. It's kind of a weird thing. So more power to the atheists if they can pull it off without all that—great. Meanwhile, I'm going to keep at it.

Amen.

I made something for you. I know the Diary of a CEO audience are strivers with big goals we want to accomplish, and one thing I've learned is that aiming at a big goal can feel incredibly psychologically uncomfortable — it's like standing at the foot of Mount Everest looking upwards. The way to accomplish your goals is by breaking them down into tiny steps. We call this in our team the 1%, and this philosophy is largely responsible for much of our success here.

So that you at home can accomplish any big goal, we made the 1% Diaries. We released them last year and they all sold out. I asked my team over and over to bring them back, with some new colors and minor tweaks, and now we have a better range for you. If you have a big goal in mind and need a framework, a process and some motivation, I highly recommend you get one before they sell out again. You can get yours at thediary.com, and the link is in the description below — there should be a button just down here.

If it says "subscribed," you're already subscribed. If it says "subscribe," you're not yet — and if that's the case, please hit the button. It helps the show more than you know, and according to the algorithm, you're someone who watches the show but hasn't hit it yet. Thank you so much.

Moving on to the next items on the list: at night, once you're asleep, try to keep your sleeping environment as dark as possible. A good eye mask is useful, and some people like earplugs too. If you wake up in the middle of the night, do some long-exhale breathing, or try the eye exercise of moving your eyes up and to the side, then counterclockwise and clockwise.

At night, dim the lights. Bright lights stimulate cortisol release, and you want your cortisol low at night. Everyone says to dim the lights because bright light suppresses melatonin — that's true, but that's only half the story. The other reason is that it increases cortisol.

Phones and screens

On the question of phones at night and blue light: dim your phone, or program it — for example with a triple click — to switch to a red screen. To be reasonable about it, no screens in the last 30 minutes before sleep, and in the first 30 minutes after waking you should be looking at the sun, exercising, hydrating, and doing that kind of thing.

Sleeping with a partner

There's the joke about chucking your partner out of the bed to sleep better. One of us is the opposite — a self-described "spooner" who sleeps best as big spoon. There are studies showing a partner does impact sleep, but as one put it, who cares? The bed-cooling setup is genuinely helpful, though, because one of us runs warm, and having another person in the bed is like sleeping with a giant hot water bottle. A cooling mattress helps with that.

You need to do a bout of work lasting 90 minutes to two hours. You have to strive, try, and learn something—do something hard mentally every day. This is critical for your ability to focus.

The phone in the room drains focus

On the phone question: an excellent study came out. They had people with their phone off, either upside down on the table, in their bag under the chair, or in a separate room. People could focus just fine in all three conditions—but if the phone was anywhere in the room, their cognitive flexibility with the material they were focusing on was diminished. In other words, it required more energy to focus, even without calls or notifications. There's apparently a subroutine running in the brain that anticipates the phone reaching for you, calling you—it's calling you even when it isn't.

So the way to increase focus and cognitive capacity is simply to get the phone out of the room. That's a big part of it. The visual field matters a lot too—the kid in school wearing a hoodie who isn't asleep is actually onto something. I discuss the history of focus tools, both pharmacology and physical devices; they used to design helmets to help kids with focus problems. The problem now is that with the phone, you've moved the whole world right in front of you, so focusing on just one spot doesn't work.

Friction and errors drive learning

Get the phone out of the room and do an effortful learning bout—and it should feel like a fight. The friction you feel trying to learn something is adrenaline. Remember how we block learning? We block adrenaline and its downstream effects with propranolol. Being alert but calm, or a little stressed, and making errors through deliberate attempts—not throwaway errors—that's how you learn.

If I can reach out and grab this pen, my brain doesn't change. One of the biggest lies in public education about neuroscience is that every experience changes your brain—that by the time I finish speaking, your brain will be different. That's absolutely not true. I study and teach neuroplasticity, and I'll tell you what induces it: being a baby trying to learn, or being an adult forcing yourself to try and learn and failing to do the thing. The error is what stimulates the plasticity.

The appropriate level of difficulty, according to computational modeling, is somewhere around 15% on average. There are two kinds of practice. One is practicing things you already know how to do—there you aim for 100% performance, reinforcing what you already know. Talk to a great dancer and they'll tell you they drill the things they already know. But when you're learning a new language, a new emotional, physical, or cognitive-emotional skill, you need to make genuine attempts and fail some of the time. Those failure signals are relayed to your cerebellum, which propagates through networks that say "change."

The conditions for plasticity

In the chapter on plasticity, there's a set of conditions: you need to be alert—I cover all the ways to get alert, including pharmacology, supplements, and behavioral tools. Then you need to be focused—I cover all the tools for focus, which you can devote to anything, not just learning. Then you need the friction and the errors, and then you need to stop. Come back a day or two later, do it again, and make sure you reinforce what you learned.

Self-testing with AI

Here's where AI is already a wonderful tool. The best way to learn is to not forget—meaning you test yourself mentally. You can use any of the LLMs; I'll go into ChatGPT and say, "Generate a short test of graduate-student-at-Stanford-level questions about neuroplasticity," and I go through it and find the one thing I don't remember. That's how you maintain and build knowledge over time: self-testing. People hear "test" and think of an external tester—you're the test taker.

The host suggested generating a quiz from the transcript of the ten protocols discussed, to be linked below for anyone who wants to take the test.

JBT is great at generating these quizzes. You can adjust the difficulty — you can even say, "I'm a professor of neuroscience and I want a 15% error rate on average."

The study I love that backs this up involved having students read the same passage one, two, three, or four times, or highlight or take notes, versus reading it just once and self-testing. When researchers checked six months and two years later, reading it once with no notes or highlighting, followed by self-testing about a week later and looking up what you couldn't remember or got wrong, led to much more stable learning over time. This doesn't work so well for physical endeavors, because there you have to actually do the physical thing and test yourself physically. But I love that set of experiments because it tells us everything we should be doing.

For me, doing this could become a book. Lately I've been podcasting and recording my audiobook. Have you done a book?

Yes. And I did the audiobook, which was horrific.

Are you due for another one?

I am. I've actually already written it — I finished writing it last year.

What's it about?

It's called Just Do It. I asked the audience multiple times, showing them hundreds of cover designs, and that was the one most of them tried to buy. It's really a breakdown of how to do the thing. I actually referenced you in the chapter about the anterior midcingulate cortex and what you said about it.

To be clear, I didn't discover that structure, but I'm happy to expound on all its incredible abilities.

I just quote what I heard you say about it on your podcast, but I'll show you what I wrote.

Cool. I'll get a copy — I'm late to the train, obviously.

I think it's enriching as a person. It's not about optimization per se; it's about being a human being, and learning and effort followed by learning and reward — including things that may not immediately benefit you but simply enrich your mind. If you're interested in the history of medicine, read a hard book like The Prince of Medicine about Galen. If you're interested in light, there are a bunch of cool books about sunlight coming out now from people other than me about how cool sunlight is. There are just cool books out there.

But is this linked to brain health and dementia, these kinds of things?

To some extent, yes. The data on dementia say that people who stay mentally and physically active and are socially enriched do much better. In fact, Masud Husain, a brilliant neurologist from Oxford, has been talking about patients who live a very long time and have lots of plaques and tangles — the signature anatomical features of Alzheimer's dementia — but no dementia. These people are exercisers and stay avidly engaged in learning. So there are a lot more people with "Alzheimer's" walking around than we think: they have all the diagnostic features except the memory loss and dementia. This suggests that, to some extent, the physical ramifications of Alzheimer's and the consequences of those neuronal changes are somewhat separable.

To be fair, he also told me about Parkinson's patients who can't generate smooth movement, but if they have to escape a burning building, they can. It's a little frustrating as a message, because it could send the wrong impression that they're just not motivated enough. But it points to the fact that if motivational systems are high enough, there may be alternate motivational systems — in the same way that kids with very severe ADHD, if you give them a video game they love, are locked in a focus tunnel for two hours. That tells you they can focus, just not on things they're not really interested in. And a lot of life is about forcing yourself to be interested in things you don't really want to do.

So that's number four, and we have one left — number 10. To frame it: the last chapter of my book is on personal development. I considered writing about relationships instead, but decided against it — not because I haven't had them, or some great ones, but because people who work on that academically should really be the ones to cover it. I did include a chapter on nutrition and exercise, but ultimately I chose to write about the relationship to self.

The key question I set up at the beginning of the chapter is this. Looking at the landscape of personal, psychological, and relationship development content online, in books, and in papers, it seems to fall into two bins. One bin is about how to find what's important to you, do what's best for you, and be the person you're supposed to be for the world — and maybe for yourself too. The other bin warns that we need to be very careful about pursuing things and fulfilling roles, because we can drift very far from our core — what Martha Beck would call our essential self. I'm a huge fan of her work, in no small part because she wrote about that in books that were very impactful for me. But she also has three degrees from Harvard — this is not somebody who can't get things done. She's a mom who has navigated complicated life circumstances. So I thought, okay, this is it.

Then I hosted James Hollis, an 84-year-old Jungian analyst, on my podcast, and he wowed all of us. This is a man who has written books like The Eden Project on relationships and Under Saturn's Shadow on the healing and trauma of men — a brilliant thinker. He said there are three things you have to do every day, and he encourages his patients to write them on their refrigerator or carry them around.

First: shut up. I expected a nice, gentle analyst, and instead he says, "Shut up. There's always somebody suffering more than you." You have to have a gratitude practice. I spent some time in the book on what that really looks like, because there's a science of gratitude alongside the common understanding of it. It's not just about listing the good things in your life — it's really about giving gratitude and receiving gratitude, and I discuss how to accomplish that.

The second thing — and by now I figured he'd soften up — is suit up. You won't do well at anything in life unless you prepare: get up in the morning, take care of your health, shower, brush your teeth, get organized. It sounds a bit like Jordan Peterson's "clean your room," but edgier: how could you possibly perform well on an exam, in a relationship, in a sport, or at work if you don't do your homework? I thought, this guy is pure boomer wisdom.

Then he said the third: show up. Happy people fulfill outward roles for the world — father, mother, sister, brother. They see themselves, though this isn't the totality of who they are, as somebody who needs to fulfill roles: teacher, mechanic, engineer, podcaster, whatever. You have to shut up, suit up, and show up. There is no human being who doesn't have to do stuff for the world — you can't freeload.

But then he added the other bin: if you carry on like that for 10, 20, 30 years, you can end up quite happy — but most of the time, people who just do those things end up pretty miserable. So once a day, you need to get out of role fulfillment, out of preparation, and out of trying to be more grateful.

You still need to do those things, but you also need to step out of them—what he called exiting the stimulus-response mode of being. That could be sitting quietly in meditation, drawing, or listening to music. You're not trying to accomplish anything; you're just letting your unconscious mind feed you information about what he called your deepest heart's desires.

My reaction was, "Yes, this is why we go camping." He said yes—extended breaks work too. You can go backpacking, you can run, you can allow this to happen in any number of ways. But once a day, take some space for yourself and just touch in with yourself.

If you're sitting there expecting an answer—"Okay, what do I want to be when I grow up? It should happen now"—that's not how it works. Your unconscious mind speaks to you in emotions and analogies, and it sets you up to go back into life able to see connections and start navigating in new and interesting ways—ways unique to your heart's desires about what you like and don't like, so you know those choices are in keeping with who you are.

I can't tell you what your deepest heart's desires are. Only you can come to that clarity, but you need to do it through a practice where you're not trying to be the football coach, the mom, the best at this. You need to listen to yourself, while also continuing to fulfill those roles. He and I both agree on this, and I mention it often because I get asked all the time, "How do I find my calling?" You find it while working your butt off doing something else. You don't find it by sitting around waiting for it to reveal itself.

You work hard at that something else, maybe even hate it. So you move to something you hate a little less, then a little less again, and eventually you get pulled forward to the thing that is your true self.

And there isn't necessarily a single answer. When people talk about "finding your passion," passion happens to be a singular word, which can be distorting—it makes you think almost like an Easter egg hunt, that you have to search for it and there's going to be exactly one somewhere.

I can handle five-year chunks. Maybe that just reflects years of earning degrees—three to five years for this, then three to five years for that, postdoc, graduate school, and so on. I'm navigating from 50 to 55 now. That's what I know: what I'm going to carry forward—exercise, faith, hydration. But I don't know what's coming next. I've never been 60 before.

The first question is a technical one about sleeping position: does the way you sleep at night produce different outcomes for your brain?

During sleep, there's a washout of waste products from the brain. That's very important for offsetting dementia, very important for feeling rested — and if that's not enough incentive, very important for getting rid of bags under your eyes. Have you ever seen yourself after one night of bad sleep? Then sleep well for two nights and look again — you're your handsome self again. What is that? It's the accumulation of lymph and other fluids and waste products under the eyes, and sleep flushes it out.

During sleep, there's lymphatic clearance, and it seems it can be slightly but significantly improved by sleeping on your side with your head slightly elevated. We used to think it was slightly inverted; now we think it's slightly elevated.

When you get up in the morning, I'm a big fan of movement. I have an inversion table — you lie back and hang upside down, which feels good on my back, though most people won't get one. Some people shake out, some jump rope — you can just move, because the lymphatic system is remarkable: one-way valves stacked from your feet all the way up to your brain. People think of lymph and lymph nodes in terms of immune checkpoints, which is true, but the lymph system also takes liquid and dumps it back into your blood circulation. It can accumulate when you're lying down — that's lymphedema, the swelling of the lower limbs. So you need to move: moving squeezes the lymph up through those one-way valves and back into general circulation.

Your brain doesn't have that mechanism. Instead, miraculously, in sleep the astrocytes — the glial cells — create a bit of extra space in the brain between neural tissue, allowing the waste products — the "glymph," as we call it, glia plus lymph — to flow up and out toward the surface of the brain and then dump out of the brain, still within the body. The puffiness of the eyes, the anterior chamber of the eye, some of the cloudiness of the eye — these systems are shared, and some of it actually comes out through the nose, which is wild. So get upright and move around. The tapping and shaking techniques look silly — like you've been in California too long — but they can help move lymph out. Sleep does this too, clearing glymph.

There's also a recent study published in Proceedings of the National Academy of Sciences, which I detail in the book, showing that a short meditation, believe it or not, increases glymph clearance during the daytime. This is super interesting for those of us who always want to figure out how to get by with less sleep while still feeling great and not short-circuiting our health. It turns out regular meditators can probably shave an hour off their sleep with 20 minutes a day of meditation, because they're getting glymph clearance during the meditation.

The timing and length of sleep have a lot to do with body temperature, but there also seems to be a drive for glymph clearance that says you need to sleep longer — which is one of the reasons you sleep a lot more when you're sick, though there are others as well.

So I'm back to meditating. My practice is pretty feeble compared to many, but here's what I do: I wake up and the first thing I do is 10 breaths of meditation. I tell myself, if I can't concentrate for 10 breaths without my mind going elsewhere, what kind of day am I going to have? And what kind of human am I if I can't organize myself for 10 breaths? Then I get out of bed, go straight to the bathroom, hydrate, get sunlight, and get some movement — these days that means a walk because of the dog. Then I come back, drink some caffeine, and exercise.

And then the 10 steps start all over again. We are this rhythm — no human being has ever escaped these circadian influences of cortisol and melatonin.

Asked whether he discusses or recommends supplements, the guest says he does, and he's constantly asked what to take. He covers alpha-GPC, tyrosine, and theanine — including theanine combined with low-dose caffeine for enhanced task switching, which he calls a very interesting literature — as well as ways to improve sleep, from tart cherry to apigenin to quviviq, one of the orexin drugs.

Pressed to pick just five supplements to take for the rest of his life, he answers:

1. Magnesium for sleep. If someone already sleeps terrifically well, he'd say take nothing for sleep. If they don't, he suggests magnesium threonate or magnesium bisglycinate — they're interchangeable for sleep.
2. EPA omega-3, at least one gram per day. He's a big believer in it for brain health, probably also cardiovascular health and reduced inflammation. He prefers the prescription form, Lovaza, because it's very high-concentration EPA, cleared of all heavy metals, and very inexpensive now that it's available generically. The challenge is getting a doctor to prescribe it — you can tell them you want Lovaza rather than taking over-the-counter options where you might risk mercury exposure. He notes he doesn't eat fatty fish himself; he doesn't like salmon unless it's sushi and just isn't good at eating seafood.
3. Vitamin D, 5,000 to 10,000 IUs per day. People object that you need a blood test and shouldn't overshoot — he agrees you shouldn't take 25,000 — but argues most people are underdosing. He's not trying to hit the RDA, nor to take so much that he blows a gasket; he wants a dose that's safe while offering additional benefits. He says 5,000 IU per day clearly has benefits beyond the conventional ones discussed — for instance hormone health: his bloodwork improves on 5,000 versus 3,000 IU with nothing else changed. He also gets sunlight. Maybe 10,000 was a little high, but he takes five to ten.
4. Alpha-GPC, 600 or 900 milligrams. It increases choline, which increases acetylcholine, which can improve focus. He's a big believer in it — not for everyone — as an alternative to going straight to a prescription stimulant, because very few things increase focus and energy without damaging sleep. Better still, alpha-GPC gives you more REM sleep. The important caveat: it can increase TMAO, which can raise cardiovascular risk. A simple mitigation is taking a 600-milligram garlic capsule — it doesn't smell like garlic — tucked in with it, anytime the same day.

Asked if that's five, he confirms: "That's five, 'cause I threw garlic in there."

To recap the list, we covered magnesium bisglycinate or threonate, omega-3, and vitamin D. For cognitive enhancement, Alpha-GPC is preferable to nicotine or prescription stimulants.

Caffeine also has great data behind it: 200 to 400 milligrams of caffeine per day has been correlated with meaningfully offsetting dementia. While the relationship is correlative rather than definitively causal, it is well supported, so I continue drinking yerba mate and coffee.

The final supplement to mention is creatine. Creatine seems to work best for cognitive enhancement when you are sleep-deprived or stressed. I have taken 5 to 10 grams per day since I was 17 or 18. In addition to any cognitive benefits, it draws water into the muscles and helps build and maintain strength when combined with training.

The interviewer asked about a viral clip in which the guest explained that going for a walk after eating can have a big impact on the body.

The guest confirmed this and pointed to a section of his work arguing that walking is necessary but not sufficient for health. He doesn't think you need to count 10,000 steps per day; 7,000 to 8,000 should be the goal. He builds it into daily life: pacing during calls, taking a walk with his team after finishing a podcast, always taking stairs instead of escalators when traveling — you arrive a little sweatier to your plane, but you're also rucking your bags.

Walking is incredible because those low-level repeated muscle contractions really help buffer blood glucose, especially after a meal. He cited a striking study on the soleus muscle — the one under the gastrocnemius that gives the calf its width during seated calf raises. That muscle is only about 1% of total musculature, but it has an outsized and significant glucose utilization. In the study — which he stressed is not practical — people did "soleus push-ups," essentially non-weighted seated calf raises, repeatedly, and this powerfully regulated blood glucose increases, buffering the peaks. It turns out this is related to walking. He's not suggesting you do soleus push-ups, except perhaps if you're stuck on a plane or in the office — "if you're a knee bouncer, rejoice, you're doing yourself good." Some people accuse this advice of being silly, as if you'd do it all day, but his point is simply to walk, because walking produces that low-level repeated muscle contraction. The soleus is a slow-twitch muscle and seems to be — he hesitated to call it a sink — an unsuspected furnace for glucose utilization.

Asked why that matters, he explained: you don't want big peaks in glucose. A big peak triggers more insulin secretion, which is insulin's job — to make sure glucose is managed. You don't want glucose too high, but you don't want to be hypoglycemic either; that can be deadly. When people eat, blood glucose rises, and while the peaks are manageable, buffering them — flattening them out with 5 to 10 minutes of walking after a meal — means fewer energy crashes. In theory, over time, your metabolic health can be better, or at least not get worse.

He mentioned that Dr. Rhonda Patrick has pointed to a comparison study where people either walked about 30 minutes per day after meals or did roughly 10 air squats every 45 minutes, and the results looked comparable — maybe the air squats were even better. But he joked that he isn't going to stand up and do air squats in a restaurant or on a New York street after dinner with friends; they're going to walk. He wasn't disparaging Rhonda — she was pointing out a mechanistic feature, not necessarily a protocol. Still, if you're stuck on a plane, you could do some air squats or bounce your knee, since non-exercise activity thermogenesis is a massive contributor.

Non-exercise-induced thermogenesis is a massive calorie burn. People who move a lot tend to be lean. I go back to my undergraduate days working on metabolism and physiology, to scientists like Rothwell and Stock, who figured out that some people could eat far more than you would think they needed yet always stayed lean — it turned out they were moving a lot during the day, burning up to 1,800 calories a day. That's extreme, but some people who just move a bit more burn a thousand calories per day.

There's a paper published in Science showing that the decline in metabolism we all associate with aging — "metabolism slows as you age" — isn't true. If people maintain muscle mass, that decline doesn't happen. And you might say, okay, so aging means muscle mass loss means reduced metabolism. Actually, no: people are simply moving less. As I've been absorbed with longevity like everyone else, I've looked at older people, particularly people in their 80s, and what I see is a lot less spontaneous movement — and a lot of mouth breathing, which at rest is not good. We know it deprives the brain of oxygen. You can mouth-breathe during exercise, but you don't want to be a mouth breather in sleep or in wakefulness.

Then you look at guests like James Hollis or Twyla Tharp — I don't know her exact age, I think she's in her early 80s, but she's a choreographer and world-class dancer who deadlifts a lot, works out for two hours a day at 5 in the morning, boxes, and choreographs. They're so mentally sharp and physically lean. Or my Stanford colleague Mike Snyder, who's in his 70s. You look at them and ask, "What's going on?" They're moving all the time. They're mentally active, they have good posture, they're exercising — but they are moving, moving, moving. The spontaneous movement is burning calories. That's one piece, but it's also the glucose regulation and the fact that they're not sitting stagnant.

Bla Norton has pointed out quite beautifully what the problem with caloric excess actually is. Setting aside the body-fat aesthetic piece, it's a toxicity of excess energy. The world's expert in mitochondria, Jared Rutter, recently came on my podcast — he's a phenomenon in the biochemistry and genetics of mitochondria — and he'll tell you that when you overload a system, and therefore a cell, with calories, the mitochondria and the whole energy management system of the cell gets sick. Your metabolism is the collective makeup of all these trillions of cells, so if you jam too much fuel in there, they don't work as well.

And caloric restriction at times might be beneficial; caloric maintenance, maybe a little more, at times a little less. This is good. So movement, movement, movement — because it's obviously calories in, calories out.

"You know what this is, right?"

"You're telling me I need to stop."

"No, no. This is not a clock. This is a CO2 monitor."

"I thought it was a lux meter. Okay. Oh, we have a lot of CO2 in here."

"Yeah, it's something we always have in the studio, because I learned over time that the higher it got, the more tired I felt. There's not great ventilation in this studio — we started at 600 and we're now at 1,700."

"And we're under short wavelength light. But before we came in here, what did we do? We went outside and had a blast of full-spectrum sunlight."

"Yeah, I think about this a lot now when I'm trying to do good cognitive work. I read some studies that if CO2 gets above a thousand parts per million, cognitive performance starts to go down."

"Well, if your cognitive performance gets any better, we're all hosed."

"You're very kind, Andrew. Thank you so much, for so many reasons. It's such an honor to get to learn from you. But I'll be honest — there's no books that I've been waiting for. Is there any book in my life that I've been waiting for? No, there's not."

This is the only book in my life that I've been waiting for, for years now. I say that because I believe in your approach — your scientific rigor, the nuance you apply, the stories you tell, the experiences you've had, and your almost mesmerizing ability to remember things and names. You didn't reference a single study without also naming its author, and I kept wondering how you do that.

Years of training, and advisers who drilled into me that attribution is important.

There's so much information out there around health and everything we've covered today, but I was waiting for your book because I'm not very good at reading books.

Well, there's an audio version too if you prefer. It'll be a long run.

No, I'm trying to build my anterior midcingulate cortex, Andrew. I always told myself that whenever you published that bloody book, I would read the whole thing from cover to cover — and I believe this is the first copy in the world that's been printed.

This is my chance to say what I've been waiting this entire podcast to say: the copy you're holding is the very first and only hardcover copy that I have, have touched, or have seen. And I'm gifting it to you. I want you to have the book — seriously. I'll sign it if you want, or leave it unsigned if you don't. It would be an honor, because I've learned so much from you. You've been an amazing colleague, friend, and supporter, but also just an amazing human being — a truly good one. Having spent time with you on and off mic, the number one thing people should know about Stephen is that he is who he appears to be: a super kind, curious, loving person. Flawed, like the rest of us.

Albeit less flawed than me, that's clear. But you really are a great human being, trying to do great things for everyone around you and for the world. This is a vastly lesser token of my gratitude than it could or should be, but I'd like to give it to you.

It's such an honor. I was actually thinking of ways to steal it.

Well, now it's a gift. And I'm going to go read your book, and I look forward to your next one.

Thank you. It's a beautiful book, and I'm really glad it netted out at the size it did — I think it's the perfect size. As I was flicking through while you were speaking, jumping between sections, I thought you did a wonderful job making it accessible. I'm not the smartest cookie when it comes to science, but I was able to understand everything, which is remarkable. It's also gorgeous. I dare say — and I'll probably get flak for this — the British versions of books often look better, and I always wonder why the American versions are a little uglier.

The aesthetics in Britain — people dress really well there. They pay attention to the little details, in their shoes and so on. They dress really smart. I'm a big fan of Ben Sherman and Fred Perry clothes, and it's the details that make those look so cool.

This felt like a very European-designed, beautiful book. And your podcast is incredible, too. So many of the guests I've had on here are because I listened to your show, got my mind blown, and then told my team, "This person is unbelievable." Whenever someone in my life is really struggling with something, I search for it, usually on YouTube, stumble across your channel, and find an episode on that exact topic — and I'm always sending those around. So I highly recommend that anyone who subscribes to my channel also subscribe to your show; I'll link it below. It turns out Huberman Lab is the gateway drug to Diary of a CEO for science and health content.

Literally and legally, it's worth being honest about it. And you've got to get the book — it's finally here, coming out in September. Since this episode airs in September, it should be available for pre-order or order now. You have to go get it. For me, it's the definitive book on this subject. Thank you so much, Andrew.

Thank you, Stephen. I loved this conversation, and I hope we can have another one sometime soon.

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