Dr. Matt Walker: How to Structure Your Sleep, Use Naps & Time Caffeine | Huberman Lab Guest Series

welcome to the hubman lab

guest

series

where i and an expert

guest

discuss science and science-based tools for everyday life. I'm Andrew Huberman and I'm a professor of neurobiology and ophthalmology at Stanford Medical School. Today, March, the 3D episode of our Sixth Episode Series, All About Sleep with expert guest Dr. Matthew Walker, during today's episode we look at how to

structure

your

sleep

for optimal mental health, physical health, and performance. We looked at monophasic

sleep

schedules, which are the more typical sleep schedules where you go to sleep at night and then wake up in the morning, so you sleep in one shift rather than polyphasic sleep schedules, which are when you sleep in two or more shifts, either at night or perhaps a shorter shift of sleep at night and another shift of sleep during the day.

We also discuss napping, including how to take a nap, how long the nap should be, whether

naps

are good or bad, in particular whether they are good or bad for you, it turns out this varies depending on the individual, we also discuss

your

sleep needs and

naps

. They vary throughout life and we analyze the position of the body during sleep, which may seem excessively detailed, but it turns out that the position of the body during sleep is essential to ensure that the sleep obtained is optimally restorative, as occurs with the first two episodes of this six-episode

series

, the third today.

The episode is packed with science—namely the biology of sleep, naps, and body position, and how they relate to each other—as well as practical tools you can use to greatly improve your sleep. Before we begin, I would like to emphasize that this podcast is independent of my teaching and research duties at Stanford; however, it is part of my desire and effort to bring consumer information about science and science-related tools to the general public at no cost, consistent with that theme. I would like to thank today's podcast sponsors our first sponsor is Mejorayuda Mejorayuda offers professional therapy with a licensed therapist conducted online.

I have been doing therapy for over 30 years. At first I had to do therapy against my will, but of course I continued to do it voluntarily over

time

. because I truly believe that doing regular therapy with a quality therapist is one of the best things we can do for our mental health. In fact, for many people it is as beneficial as doing regular physical exercise. The best thing about better help is that it makes it very easy to find a therapist that is optimally suited to your needs and I think it is fair to say that we can define a great therapist as someone with whom you have a great relationship, someone with whom you You can talk about a variety of different topics and they can't provide you with anything. just support, but also information, and with better help, they make it extremely convenient to fit into your schedule and other aspects of your life.

If you want to try Betterhelp, you can visit Betterhelp.com Huberman to get 10% off your First month again, it's Betterhelp.com Huberman. Today's episode is also brought to us by Element. Element is an electrolyte drink that has everything you need and nothing you don't, that means lots of electrolytes, magnesium, potassium and sodium, and no sugar, as I mentioned before. On this podcast I'm a big fan of salt. I want to be clear that people who already eat a lot of salt or who have high blood pressure or who eat a lot of processed foods that typically contain salt need to watch their salt intake.

However, if you are someone who eats fairly cleanly, exercises, and drinks a lot of water, there is a good chance that you could benefit from getting more electrolytes with your fluids. The reason is that all the cells in our body, including nerve cells, neurons need electrolytes to function properly, so we don't just want to hydrate ourselves, we want to hydrate ourselves with adequate levels of electrolytes with an item that is very easy to do. What I do is when I wake up in the morning I consume about 16 to 32 ounces of water and I will dissolve one element packet in that water.

I'll also do the same when I exercise, especially if it's a hot day and I'm sweating a lot. and some

time

s I even dissolve a packet of the third element in water if I exercise very hard or sweat a lot or if I just notice that I am not getting enough salt with my food if you want to try the element. you can go to drink element written LM nt.com

huberman

to claim a free element sample pack with your purchase again, that's drink element LM t.com. Today's episode also comes to us on awakening awakening is a meditation app that has hundreds of different meditations as well as scripts for Yoga Nidra and sleepless deep rest protocols or nsdr, there is now a wealth of data showing that even Short daily meditations can greatly improve our mood, reduce anxiety, improve our ability to concentrate, and improve our memory while we're at it.

There are many different forms of meditation. Most people find it difficult to find and follow a meditation practice in the way that is most beneficial for them. The awakening app makes it extremely easy to learn how to meditate and carry out your daily meditation practice. One way that will be more effective and efficient for you includes a variety of different types of meditations of different lengths, as well as things like Yoga Nidra, which place the brain and body into a kind of pseudo-sleep that allows you to emerge feeling amazing. mentally refreshed, in fact, the science around Yoga Nidra is truly impressive and shows that after a needra yoga session, dopamine levels in certain areas of the brain increase by up to 60%, putting the brain and body body in a state of enhanced readiness for mental work. and for physical work, another thing I really like about the awakening app is that it provides a 30-day introductory course for those of you who haven't meditated before or haven't gotten back into a meditation practice that's fantastic or If they are someone who You are already an expert and habitual meditator.

Awakening also has more advanced meditations and yoga sessions for you. If you want to try The Waking Up app, you can go to wakeup.com

huberman

and access a 30-day free trial again. waking up.com huberman and now for my conversation with Dr. Matthew Walker Dr. Walker, welcome back Dr. huberman, it's an absolute pleasure, let's talk about the different types of sleep because I think most people think that the dream is just one thing. Most people sleep at night. Some people. also take a nap, a topic that we will also discuss today, but it turns out that there are many different types of sleep, what are the different types of sleep and what do they do for us and um, I guess you're probably all wondering by now, I'm certainly what types . of the dream, are we already participating in the meaning?

Am I involved in or having multiple types of sleep each night? This is a fascinating question and goes back to something we discussed in a previous episode: the different stages of sleep and how they develop. I've described those fascinating things, what you're already asking is an incredibly subtle but relevant question: how should I sleep in terms of sleep phases? Should it have a phase? Should I have two phases of sleep? many phases of sleep, you can sort of answer that question based on lifespan, because how we sleep in terms of those fragmented sessions changes as we develop a clear nomenclature.

I'm saying single phase, basic, polyphase, unpack that single phase. obviously it just means a single monophasic phase when you say phase you mean one period of correct sleep so it would be within a 24 hour period that you are having a single period of basic sleep so it means that within that 24 hour phase you're having two periods of sleep and we'll talk about how those periods are divided, whether they're divided into two halves in the middle of the night or whether they're divided in terms of longer duration at night. Nap like an afternoon nap and then we can. let's talk about polyphasic sleep, the polyphasic sleep that we in sleep science have been using for many years in the context of infancy because, as all new parents will know, babies not only get a good time of sleep, they are up , they are down, they are up, they are down and they have many episodes of sleep within that 24 hour period and that is polyphasic sleep.

The other term or the other application of that term polyphasic sleep has been used more in the kind of interesting biohacker movement and we can Maybe we'll come back to that later, so how do these different phases of sleep change throughout life? Well, we've already said that when you're a baby and you're born within the first year of life, you're incredibly polyphasic and probably going through sleep phases every 2 hours, why do you do that? Why can't you just be born and sleep monophasically? It's for at least two reasons: First, a baby needs to feed every two hours.

Your energy needs and food intake requirements dictate that you can't sleep for long because you need to be awake to feed and then go back to sleep. Probably within the first six months things will start to change a little bit, but the second reason you are highly polyphasic when you are born is because your super chiasmatic nucleus and in another episode we talked about this 24-hour central master clock that marks your Cadian rhythm, the rise and fall, the wakefulness and the sleep you have. hasn't developed yet, this 24-hour clock hasn't been set in the brain, so the baby apparently doesn't know anything about when it's light or when it's dark outside, it just wakes up or sleeps awake a sleeve, so that is the second reason why you need energy feeding. it is the first and then the absence of a fully developed 24-hour brain clock to overcome that beautiful dictated rhythm.

At about one year of age, the number of sleep phases is starting to decrease, but it's still highly polyphasic, it's not until you're probably two or three years old and now you're starting to see this consolidation of sleep. What do I mean that sleep now occurs more predominantly in the night phase of the 24 hour cycle and there are some moments of sleep during the day, so maybe when you're in kindergarten you only have two hours of sleep, so now we've switched from polyphasic sleep as a baby to basic sleep in kindergarten. Could you describe what the basic patterns I remember from kindergarten were?

At that time of the afternoon they put out these little mats and every kid just wants to roll up, it actually sounds really good, you know I wouldn't do it and we'll talk about how some adults do this too, but almost every kindergarten system I've asked about about different nations around the world, they all have this nap time and any teacher will tell you if one of those kids doesn't take a nap during that period of time, it's the Loose Canon, it's the live wire and in later episodes we. I'll talk about exactly how sleep harnesses and improves our emotional and mental health and how it falls apart when we don't, that's how it's certainly coming about biologically and that's how we as a society respect that and adapt to that and then probably the age of start school, so around age five or six, we're now starting to see children with completely monophasic sleep who sleep for long periods at night and then can stay awake during the day, at which point you've locked in their monophasic pattern and It continues throughout adulthood and into old age with some caveats we will talk about, this is how sleep develops into monophasic biphasic polyphasic sleep throughout life;

However, it doesn't fully tell you how those different stages of sleep change throughout life. So I have shown you the view of sleep throughout life through a microscope lens. If we click on a lens and focus deeper on the different stages of sleep, there we see a fascinating story in uo for the most part. a sleep-like state as a fetus once you reach a certain point of development in the womb, that sleep-like state seems to be more of something that resembles REM sleep, now it's not full REM sleep yet, but it seems to be something very similar to REM sleep.

I say this because in the first episode I told you that as we enter REM sleep and begin to dream like adults, the brain paralyzes the body so that the mind can safely dream those kicks and those punches and those elbows that uh, a mother will feel that the fetus seems to be during this dream state often and I don't want to break any illusion that you start singing or you're singing and you get these hits and these elbows and these kicking legs and it's beautiful. It's beautiful, but it turns out that it's probably the REM sleep state,but the kind of muscle paralysis hasn't developed yet, so you're experiencing these electrical bursts, this frenetic REM sleep activity that we described, but you're not getting any motor output blockage and that's why it expresses itself as these kicks and kicks. these bumps and then for the first six months of life and at that point in the first 6 months those babies sleep between 14 and 17 hours a day, that's huge.

It's not like that, I mean it's right up there if you look at philology and ask which is, by the way, a fascinating topic. At some point we should do a separate podcast on sleep in different species because I know that, like me, you love it, you know? all variety of sweets, but you have elephants that sleep only 4 hours and then you have the little brown bat who is the sleep star and will sleep almost 17 to 18 hours a day. Outside of being lazy on that note, can I ask you a question about that little brown one?

Yes, he sleeps hanging upside down, so he can't get sleep paralysis in his little claws, so he won't get that paralysis, but he goes through the stages of sleep very quickly and this happens to birds too, so birds that grouped together on a branch they will sleep and sleep in fascinating ways, like sometimes with half the brain. sometimes with both halves, but then you say well, if I'm on a branch and there's this wonderful force called gravity underneath me and I go into REM sleep and I have that muscle paralysis they do, how does it work?

They only have a very brief muscle paralysis. Periods of REM sleep that last only a few seconds and then regain muscle tone. I couldn't, I couldn't help but ask, it's great, the flora and fauna. Especially that fauna, um, I love it so much, so no. They want to throw us off course, but now we know they can, that's why bats don't fall, that's why birds don't fall, right, so when you're a baby sleeping 14 to 17 hours, what's going on with those different stages? of non-rem and REM sleep at that point we can't really define and separate the different stages of non-r sleep because it's not fully formed yet, but we have what looks like an active state of REM sleep and a state of deep non-rem sleep. passive rem.

I say that almost 50% of the time a baby and newborn sleeps is spent in REM sleep. Why do I say that with a certain amazement in my voice? Because as adults we may be reduced to maybe 20% of the time we spend asleep. in REM sleep, but 50% of the time when a baby is asleep they are in rem sleep, why would that be the case? In all species that have REM and non-REM sleep, the time when we see REM sleep in greatest volume is always after birth. there is something special about REM sleep and its function during that early period and now we are beginning to understand why when you are born you are still going through a lot of brain maturation and the recipe for the day there, unlike when we were teenagers, is exploding the brain with synapses, all these connections throughout the brain, what we've discovered is that REM sleep acts as an electrical fertilizer to stimulate the growth of these connections within the brain.

It's almost like you can think of an Internet Service Provider with this. huge new neighborhood and the first wake-up call is to go in and connect each of those houses with these fiber optic cables, that's what REM sleep does and if you start to deprive yourself, and these were studies done many years ago by Howard RTHOR . and others, if you deprive animals of REM sleep, you stunt the development of the brain and, presumably, the entire animal, and yes, as a consequence, I mean, if you look at their social behavior, even that is profoundly abnormal because we don't have it.

Brain developed during REM sleep. I mention this not because there is causal evidence, but rather because we have seen profound disturbances of REM sleep in certain developmental disorders such as autism and ADHD. I don't think there is any supporting evidence yet to make a claim. That part of the trajectory underlying those conditions is REM sleep abnormalities, but it's a very active area of ​​research, so it's a fascinating time during childhood when you get these enormous amounts of REM sleep, why because of what which we call synaptogenesis, is simply the creation of synapses Genesis then as you go from 6 months to the next 18 months something strange happens.

Total sleep time begins to decrease. REM sleep starts to decrease, but non-REM sleep actually increases even though total sleep time is decreasing and there is a strange spike. in the lighter nonrem stage, what we call nonr stage two and those sleep spindles that I described in the first episode. These bursts of electrical activity we'll talk about the role of those sleep spindles in improving motor skill learning and we've done many, many years of work in this area, why is it relevant to this phase of life that occurs right in the moment when babies begin to skillfully coordinate their limbs and begin to walk?

We believe that it is part of the development process of the The motor system that allows walking begins in an amazing way, so things will change even more. Sleep time continues to decline and by around five or six years of age, the cocktail combination of non-rem and REM has been reduced to a stable ratio that will be maintained throughout life, which is a 4:1, so that approximately 20% of the time you are asleep will be REM sleep and the remaining time will be 80% of that time will be non-REM sleep, as long as one sleeps enough total amount correctly and does so at the correct times in time that we described in the first episode, achieving that kind of proper chronotype match with the 24-hour clock that will certainly alter those things as well, that's how sleep develops both in the first level of the monophasic lens, basic polyphasic and then, double clicking on how the different stages of sleep develop and what are the reasons behind that, then I said that once we are adults we become monophasic, yes to some extent, but there is some controversy about the way we sleep in the modernity that perhaps we are not.

Sleeping the way we were designed to sleep, which brings us back to basic sleep. In the first episode we talked about this strange drop in our alertness after the afternoon that occurs called the postprandial drop and it happens sometime between 1 and 4:00 p.m. region and is measurable and appears to be biologically connected to us if we look at certain cultures that are not affected by modernity, so we and others have studied hunter-gatherer tribes studied, they don't sleep like we do and they don't. They don't sleep like we do for at least two reasons: the first is that they often have a nap-like behavioral pattern, where, especially in the hot, dry season, they take a nap in the afternoon; in the wet and cool season, this may not be the case. is the case, but they certainly have a more basic pattern where they sleep more at night and then take a short nap like the siesta and then of course there are the Latin and Mediterranean cultures and they have this practice of nap type behavior coming back. hunters gather tribes the way they also don't sleep in a similar way to what we do is the time of sleep, they don't go to sleep when the sun sets, usually, on average, as a group, they will generally go They sleep about 2 hours after sunset and then they will wake up not with sunrise, they wake up just before that and you think how they predict the light.

No, what changes first before the sun actually rises is the temperature and temperature is a very strong predictor of forcing them to wake up, so when you think about how they sleep, consider the term midnight, most of us never really think about it. What the term midnight means refers to the fact that it is the middle of the night, but For most of us in the modern world, that is the time when we think about sending our last email or posting on social media . Midnight is no longer midnight for society, but it is for them. So should we think of midnight as the middle of the day? night in the context of the extreme morning person person you probably know likes to go to bed around 8:00 p.m. m. wakes up around 4:00 a.m. m. most people listen 4:00 a.m. m. and they go, oh God, you know it's early You know, the mighty Joo Willink is famous for posting images of his digital watch of his.

I usually think it's 4:30am. when he wakes up and that's when he starts his workout so his Twitter and I guess they call in this podcast where you talked to him before, but he goes to bed pretty early, that's how he is most nights, so in a sense. You know, midnight for him or someone with a similar schedule is really the middle of the night, that's right, but for the other chronotypes, people who prefer to go to sleep or who naturally get sleepy around 10 or 11 p.m. or even later, how should they think about this basic multiphase business?

Because, on some level, we all have to balance our sleep schedule with the demands of work and family, etc., that's right, so I was very specific when I said. On average, hunting tribes gather that's how they sleep, but like the rest of society, there's a huge spread and there will be a proportion of them that will be a bit like Joo, who will be on the early side of that in The It's a very early part of that, but then there are other people who are clearly night owls and may not go to bed until you know 10: or 11: and wake up later, so there is a distribution there , You do not have to worry about that.

My average midnight statement seems to be that when we are dislocated from all the trappings of modernity, how will a representative group of humans sleep on average, but, as I said, there are huge differences from individual to individual in the way we can sleep. ask ourselves why we have these things called chronotypes. Why is there so much variability in how people prefer when to sleep? Wouldn't it be easier if biology designed us all to be asleep at the same time? That's not what we mentioned. in the first episode, sleeping is really idiotic in the sense that you know you're not protecting yourself or the people you care about and if everyone slept at the same time, you as a collective and as an individual would be vulnerable to a period of 8 hours from 7 to n, but through this wonderful injection of variability in terms of people's preferences for when to sleep, maybe there will be some people who go to bed at 8:00 p.m. and there are other people who wake up at 4:00 a.m.

There are other people who go to bed at midnight and wake up at 8:00 a.m. so then think about that at some point what you have done is that there will always be someone or a group of people awake until midnight and then there will always be a group of people who are awake from 4:00 am. m. so that, as an individual, everyone has their 8-hour opportunity, but as a collective, as a clan, it is you. I have reduced their vulnerability by 50% because Mother Nature injected variability through chronotype genetics to distribute that and lessen the burden. Does that make any sense and reminds me of what the circadian rhythm is like that we discussed in episode one? about 24 hours, not exactly 24 hours, the rhythm of the supermatic nucleus neurons that generate the circadian rhythm, as I remember, is rarely exactly 24 hours, it is 24.2 or 24.4 and the idea in mind, the story is that this variation allows the coincidence of drag to the external light and darkness cycle that changes throughout the year, so it is not recommended that it be rigid 24 hours because if there is any variation in light and darkness, which by Of course there is, you know that even at the equator throughout the year there are subtle variations, but certainly. move away from the equator and then these variations in you know your circadian rhythm uh scn clock supermatic core could be 24.2 mine could be 24.6 24 someone else 24.1 and in that sense it allows some malleability to match the circadian rhythm with the outside light and dark rhythms It's a decent parallel to what we're talking about, it's a beautiful demonstration that there's always some wiggle room in how biology is programmed because a certain degree of noise, almost sarcastic, can be very beneficial and it's much more predictive in the way how the world works and it's much more adaptive for a species to implement and embrace that kind of variability and yours was a beautiful example of it lasting about 24 hours, but certainly responding to changes in light duration around the world. . the year and it has to be because we need to buckle into the light and dark cycle for optimal survival and here is another demonstration that it is not about the Cadian rhythm but about the distribution of the chronotype, not within an individual throughout the year but between individuals. at any given time and that variability once again provides a biological benefit in thefirst episode and again now you're talking about chronotypes and one thing I wanted to ask is that you said that chronotype is genetically determined but that necessarily means it's inherited directly from mom and dad, which means if your parents are both extreme early morning types , will you grow into an extreme early morning guy?

You already established that during childhood and development, adolescence, etc., our chronotype is somewhat masked by some. developmental uh um uh Needs um, but once we reach adulthood and our chronotype has been established, can we consult our parents to determine if we are more likely to be morning people or late bloomers? It's very unlikely that you'd find someone whose parents were extreme morning types being neutral or evening types and vice versa, so I guess people who, if they know their birth parents and know their rhythms, you're very likely to do that. sometime. Acquas in your life is very similar to them, now there are certain conditions and life contexts where you can fight against that, um, if you really like it, you know if you're someone who's in a punk rock band and you're on tour. all the time even though your mom and dad may be the morning type and you may be the morning type you're on the road you're playing gigs there's no chance but at some point let's say you retire and you give yourself a chance to express yourself. natural rhythm you will return to that, so yes, it is highly genetic, it is not completely genetic, there is a certain degree of modification that occurs depending on the context and I just gave you a good example of context and also your exposure to light.

You may be someone who is, let's say, neutral like me, but if you are constantly invaded by the Electric Light at night, you are drinking too much

caffeine

and you are on your laptop, your computer and your phone, and you are always activated by social media, It's very easy for someone like me to get sidetracked and become a 1 a.m. person. at 9am, that's not my natural type, but the context and environment has changed me, but For the most part, yes to your question. I would like to take a quick break and recognize our sponsor. Ag1 Ag1 is a probiotic vitamin and mineral drink that also contains adaptogens and is designed to meet all your fundamental nutritional needs.

I'm sure. You all have heard me say that I have been taking ag1 since 201 12 and in fact that is true now of course I eat whole foods every day. I strive to get those foods primarily from unprocessed or minimally processed sources, however, I find it difficult to get enough servings of fruits and vegetables each day, so with ag1 I make sure I get enough vitamins, minerals, prebiotic fiber, and other things that They are usually found in fruits or vegetables and of course I still make sure I eat fruits and vegetables and in that way it provides a kind of insurance that I am getting enough of what I need, plus the adaptogens and other micronutrients in ag1 They really help buffer stress and ensure my body's cells, organs and tissues get what they need.

People often ask me if they were going to take the Just One supplement what should that supplement be and I always answer ag1 if you want to try ag1 you can go drink a1.com huberman to claim a special offer you will get five free travel packs plus a annual supply of vitamin D3 K2 again, that's drinking a1.com huberman, okay, back to these different phase opportunities for sleep, I'm clearly wrong in the language, but basic monophasic and polyphasic vacular, could you? Give us some more examples of different types of biphasic and polyphasic sleep, so going back to basic sleep, I describe a version once we are adults, which is the notion of Nap, a long episode at night, a short episode during the day and that episode during the day. generally coincides with that drop in alertness that we described, it hits that sweet spot right there and it's pretty easy for some people to fall asleep anywhere from one to four 1 to four yeah, and I know that's a big window, but that just lets us know if you're someone like you who's a morning type, you'd probably start wanting to take a nap a little bit earlier or if you were basic, someone like me, neutral, probably an hour and a half, two hours. later still, but there is a different version of basic sleep for adults that has been described in the literature and it is fascinating, but I don't think it is biological, it is the notion that some people will have heard called first sleep, second sleep and now you are dividing. your sleep in two phases, but they are divided throughout the night, so the idea is that you fall asleep and maybe have 4 hours and then you wake up and then you are awake for several hours and then you go back to sleep for another 3 or 4 hours if you look at history and the record of human history, it's very clear that there were some cultures doing this, particularly if you look at some of the European cultures, Britain in particular, there's good evidence that somewhere between about 15th to 19th centuries seem to have ended during the type of Dezian era that people were describing this behavior and waking up in the middle of the night after about 4 hours preparing food playing music writing making love was a real thing and I'm not suggesting it didn't happen. , clearly it happened and there is a great book that describes this, but is this how we were designed to sleep biphasically versus napping?

I don't think that's the case, if you look at the biology of our human rhythms, there is no good body of evidence to support that there is this magical period of a big spike in the Arcadian rhythm that occurs right in the middle of the night and that should force us to wake up. There is an article that is often cited for this and, in truth, that article, if you read it, doesn't say anything about the first dream, the second dream doesn't talk at all about the basic dream and I think that article is used unfairly as justification of the first dream and the second.

Sleep and the article for me has at least three problems. It's a great article. There is no problem with the article and its hypothesis, but its use as justification for the first dream. The second dream has three problems. The first is the artificial nature of the study. They didn't design it to test the hypothesis, but they had individuals in bed for 14 hours versus a standard 8 hour period, and sure enough, what they found was that when you force people night after night to be in bed for 14 hours somewhere after about 6 or 7 hours they wake up and then you can't get out of bed in the studio so you just stay awake and then at some point I don't know if it's out of boredom or you fall asleep again and that's argued as a clear demonstration of this split sleep, but like I said, they are generally awake for about six and a half to seven hours, plus there was no magical Awakening period, it is a probability distribution and what that means is that if You look at the data, people are more likely to wake up after about 6 or seven hours and they're more likely to go back to sleep.

It wasn't like the whole experiment demonstrated a very clear termination of the sleep that everyone was having at the time, so that's the first problem um and the second problem, which is the first problem, is something abnormal 14 hours forced in bed the second is that it was not a clear separation, it is simply a higher probability the final problem is that it was a study done on only seven individuals, healthy men, so I have yet to see it, you know, expanded, the first dream happened, the second dream, yes it happened, is there any solid evidence that this is how we were naturally designed and have evolved to sleep?

I really do not know. I think at least I don't see good evidence right now to support that, but stay open to it, in episode one we talked a little bit about body position during sleep and how different degrees of tilting or lowering could affect some of the characteristics of sleep and I can't help but ask now how you described this basic pattern for people who were essentially experimentally restricted to bed. Is there something about being horizontal that makes us sleepy? And maybe it's not for the reasons. What would you think, which is fine, I'm just preprogrammed when I lie down and my head hits the pillow, it turns out that it seems to be the temperature that when your body is lying down, lying horizontally, the distribution of how your body is able to move the pillow. blood around the different regions and lower your core body temperature, which means you can push warm blood from the center of your body to these surface areas and when you push it towards the surface areas you release that heat, this is enormous thermal dissipation. that happens when we draw blood from the core to the surface, you give off that heat and your core body temperature plummets when your body temperature your core body temperature drops you have a higher chance of becoming drowsy, in fact it's very difficult to fall asleep if your core body temperature does not drop and when you go to bed, what we call the vasoactive capacity of the body to distribute that blood in a way that allows thermal dissipation of the core body temperature is higher and that is the reason why It is easier for us to fall asleep lying down. downward than let's say semi-reclined or certainly fully supported upwards and is probably the reason why we naturally evolved only to lie on the floor.

Very interesting, maybe now is a good time to talk about basic sleep in the context of sleep. At night and during the afternoon nap, you mentioned this posterior partial slump that most people experience between 1:00 and 4:00 p.m. that many people try and fight with

caffeine

we will also talk about coffee uh this episode is such an interesting substance and I think the most commonly used drug is a drug after all all over the world. I believe that over 90% of adults worldwide consume caffeine on a regular basis. daily that is correct and I think that after oil it may be perhaps the second or at least the third most traded commodity on this planet and it is what we call a psychoactive stimulant it is a stimulant and it is probably one of the only stimulants that we will give it to you easily to our kids and you know, don't worry too much about it, we'll get into caffeine a little bit later in this episode, but I can't help but mention that someone, I think it was Michael Polland, said. that you know caffeine is one of the few drugs that almost everyone takes, just to quote in quotes, feeling normal, yeah, exactly, you know it's kind of like I think sometimes you know lack of sleep is just the absence of caffeine and, um, it's very interesting. chemical that I've actually changed my mind about and I'm happy to talk about why I've changed my mind, but also some Gods too, we'll go there while I'll take a sip of my uh.

Triple Espresso here while we discuss while we discuss naps are good for us if we take a nap what if we don't like naps why do we wake up from naps sometimes groggy and other times feeling refreshed? Tell us about naps. Naps are good and bad depending on the situation naps can be a double-edged sword in other words, we and others have done many studies on naps and the benefits are fascinating and St. I'll tell you about a study we did, we assigned participants to one of two groups and at noon they all learned a whole list of new facts, so it was a study on learning in memory and then one group took a 90-minute sleep opportunity to focus on that fall in the state of alert, the other simply remained awake lying down. bed and they just watched a nature documentary and then 5 hours later we had them do another learning session, so they woke up after the 90 minute nap and went through that kind of initial pause about which we will discuss what that is to say, after you wake up, everyone returns to operating temperature.

In other words, I asked you to try to include a complete list of facts at noon and then a complete list of new facts again at 5 p.m. and can I ask what is the learning capacity of your brain at noon and 5:00 p.m. and is there any difference in your learning ability when you have taken a nap in between versus not? And sure enough, what happened in the group that didn't take a nap, their learning ability gradually decreased throughout the day that the nap group was able to maintain their learning and actually if anything improve it and the difference between those two groups a 5:00 p.m.

It was about 20%, so it's certainly not trivial in terms of if you say you know here's a new compound that can increase your learning ability by 20%, would you take it? I suspect it would probably make some money, so it's a demonstration of rote learning. We did another study that was very similar in terms of its design, butwe looked at your emotional brain and we showed people different types of emotional expressions and we asked them to rate them and we did it first before an app and then after a nap versus um at that same time at sort of noon versus 5:00 p.m. and another group didn't take a nap, and sure enough, the group that didn't take a nap around 5:00 p.m.

They were starting to rate the fearful and angry faces as much more fearful and much angrier, but if you looked at the napping group, it was different, they actually decreased the fear response and mitigated the normal increase in anger sensitivity to Throughout the day and the nap seemed to increase your positive appraisal of happy faces, so a nap there had the ability to reset the magnetic north of your emotional compass and there was a beneficial pink tint almost added to your vision glasses. world after you napped, which was also interesting in those two studies, two different types of sleep were passing on those benefits in the napping group that was learning, the learning benefit that they got wasn't just about them taking a nap. nap and sleep, it was about them having these sleep spindles the more of those sleep spindles you had the greater the restoration of your learning ability when you wake up for the emotional recalibration that I described in the nap that had nothing to do with the spindles from sleep or even with non-rem sleep, it required REM sleep to produce that benefit, so there are certainly many benefits and we have looked down at the body blood pressure cardiovascular measures immune health everyone seems to benefit so at that point everyone can be thinking, of course, this sounds good without mentioning the basics, which is your attention, your concentration, your focus and all your energy improves through naps, even your decision making, you said, decision making, yes, even your Decision making improves, so your ability to make the right decisions based on this weight of evidence that you're facing has also improved. almost every area of ​​cognition that we have analyzed and many areas of your emotional and mood health that we have analyzed seem to benefit from a nap at that moment you are thinking so, what is the problem?

The problem is that when you take a nap, you release some of the sleep pressure that has been building up, so in the first episode we talked about a chemical called adenosine and the longer you are awake, the more adenosine builds up, the more adenosine builds up, the sleepier you will feel. and after about 16 hours of being awake you should have plenty of healthy adenosine sleepiness in your brain to get you asleep and stay asleep and when we sleep we can flush that adenosine out of the brain so we wake up after 7 to 9 hours and if It has been a good quality sleep.

We feel renewed because we have cleared the brain of some of that adenosine. When you take a nap, like a pressure valve on a steam cooker, you simply relax some of that healthy sleepiness that you've been building up, so the dark side of napping is that if you have difficulty sleeping and suffer from insomnia, The advice is not to take naps during the day because you are setting yourself up for an even night. higher chance of failing at night because when you nap you release some of that good sleepiness that we need to develop for you as someone who is struggling with sleep to give you the highest chance of sleepiness falling on your shoulders, so if you're not you have trouble sleeping and may nap regularly.

I would say that naps are fine and we can discuss what an optimal nap is and the protocol for what the nap should be like. I'd say that's great, the only caveat is to make sure you're not sleeping. too late in the day and this is one of the components of the protocol on how to nap because taking a nap late in the day is too close to sleeping and you can think of it almost like having a snack before your main meal, a nap at the end of the day simply. eliminate the appetite of your drowsiness so that when it's time to sleep you're not as hungry anymore, so keep that in mind, but we can break down maybe the optimal way to take a nap if you're going to take a nap and exactly the two and the Lo which should not be done if that sounds in any way interesting, yes, that is of great interest to me and I know many other people.

I'm a big believer in naps. I have always enjoyed short naps of about 10 to 30 minutes, unless I am somehow sleep deprived, in which case I will sleep for an hour or even a little longer, but I make sure to set an alarm. I really relied on the advice you gave me, which was, first of all, decide whether to take a nap or not. it's beneficial for me or whoever is considering that, but then making sure that however long the nap is from zero to 90 minutes, it's not longer than 90 minutes because the real goal is not to disrupt nighttime sleep, that's right.

Basically, it's just a more verbose way of saying what you just said, so how do you determine the optimal nap length and in particular to avoid the problem of disrupting nighttime sleep when taking a nap, but also this quite common phenomenon of waking up and feeling? a little dazed or I'm even a little grumpy face after nap uh or should we call the expression after nap right the P NE what's your P? Do you wake up um in the and in the morning also some people wake up? and they're like that face and then there's the good morning, you know, and I think people who wake up with good morning are particularly charming, unless you're of the post Snap expression which is like the wrinkled face and then Just you don't want to be around those people, right, no, absolutely, um, yeah, and this probably relates to spirit animals and stuff like that, some people wake up like a happy squirrel and other people seem to wake up like my Bulldog Costello, where it's which you know, the jowl is still in contact with the floor, yeah, so I'm P.

I'm trying to keep it together and not Absol just fall apart. It's brilliant please trade the market so firstly answer your question about how to nap optimally. The word optimal is interesting. because it's when you guys say how long should I take a nap, what's the optimal nap length, the question I ask you is what are you trying to optimize because once I understand what you're trying to optimize, I can give you a better prescription without doctor, I'm talking here about a better kind of protocol advice on how to nap. I mentioned the emotional faces study in part for a specific reason because I told you that the benefit did not come through non-REM sleep. but REM sleep and in our first episode we said that when you go through these 90 minute cycles on average, you get most of the non-REM sleep first and then you'll have this episode of REM sleep at the end and it always seems to go away.

That way, when you're a normal, healthy person, you go into non-REM sleep and then you go into REM sleep. It is very rare that you ever go directly into REM sleep. There are only two reasons why that seems to happen. The first is a clinical condition. called noopsy where you can have initial REM sleep and it's very rare, the second is if you are horribly deprived of REM sleep night after night and I let you sleep, then at that point REM sleep the pressure for REM sleep has been created for The point is to be almost insatiable and your brain goes straight into REM sleep, but with those two things aside, you go into non-REM sleep first, so I mentioned the emotional study of resetting your kind of mood, uh, compass, because to get that REM sleep. you had to nap for a longer period of time because you had to first get through non-rem sleep before you had REM sleep, but let's again assume that's optimal for most people when talking about naps.

I just want a quick nap. restart I want my alertness and concentration to be failing because I'm staring at the screen or I just can't concentrate on the work I'm doing. I want my alertness and concentration to be demonstrated. I want that kind of snub. Increased brain energy where I know I can sustain myself for now for a longer period of time and I have the motivation, which is kind of how I like to think about energy. I also have the motivation, the drive to continue. going on, which is starting to fail me to understand those basic things, which is what most people nap for, aim for a 20 minute nap, why 20 minutes if I reduce the duration of the nap and have done these studies where we essentially look at what's called a dose-response curve I give you a 5 minute nap 10 minute nap 15 minutes 20 minutes 30 minutes 45 minutes 90 minutes after 5 or 10 minutes you really don't sleep much you'll wake up and you will have some degree of improved alertness and your base reaction time may be a little faster, but that fades very quickly and doesn't maintain that benefit once you get past 15-17 minutes, now things start to look different , you get these good benefits for concentration alertness. and motivation and stuff is maintained, so once you wake up, I would probably say a 20 minute nap at that point will give you a good boost in your concentration and energy sales for the brain and that will sustain you for the rest of the day. day.

In the afternoon and late into the night, the benefit of a 20-minute nap is that you don't get the PNE Andrew Hubman trademark, you don't get that almost sleepy hangover, which some people will say is strange. I take a nap, maybe I'll take a nap. minutes 50 minutes and I wake up and to be honest Matt, I almost feel worse after the nap than before and I don't understand it, it's something called sleep inertia and an extreme version of this is in the first two hours of the night . out of sleep, you get a phone call or an alarm goes off and you wake up and you're like lost in the ocean, you look around, you're in this dazed state, you're half awake, half asleep and you can respond and you can do things, but wow , you feel miserable and it's almost like you're going from the ground floor to the penthouse suite, but you get stuck somewhere in between, you know, the 13th floor and it's that difficult. indicate if you fall asleep in stage one no rem, then stage two no and just before you enter the deeper stages of no Ram 3 and four, that starts happening around 30 to 40 minutes for most people, but by breaking your nap at 20 minutes you still get these nice benefits of a good chunk of healthy non-rem sleep, but you're not going as far down the cycle as deep into your no-r that when you wake up after 20 minutes you're not where we were.

Call that inertia phase of sleep, that groggy phase of sleep, that hangover phase of sleep, so it's a nice benefit that you get all these improvements in your brain, but you wake up and very quickly you go back to the temperature of functioning and you don't suffer that inertia now. That's not to say that when you sleep or nap longer you don't start getting more benefits than you get and those benefits are greater in magnitude and sustained over a longer period of time, it's just that you have to understand the The trade-off is that you will suffer, which is that I will get more profits from my book and I will make more profits, but in the first hour or so I will have to understand that at that point I may even be performing worse than before.

I did it before I even started napping, but if you're patient and do it, the rewards on the other side are significantly better still, so that's the first tip and when it comes to how to nap, I would say dosage and the moment. making poison and venom hyperbole here, it's simply that poison is how much sleep and nursing you're going to suffer, so aim for about 20 minutes, that's what time goes back to what we described before, don't worry. you sleep too late. So what's the general rule here for an average protocol for an average adult? I would say don't take a nap after 300 pm. m. approximately. 20-minute naps between 300 p.m. and if you have difficulty sleeping don't do this at all, if not and you can fall asleep fine this seems like a good ingredient to get a basic return on your investment again if you tell me what it is. the optimal nap duration, we need to have a conversation to understand what you are looking for here, what are the benefits and then I can create a Buffet kaleidoscope that matches what you need and we can think about the nap duration accordingly, thank you , that is very informative.

I have a colleague at Stanford who is a Howard Hughes researcher, which for those who don't know, is a pretty elitist academic research club that you essentially have to try, you can do it every time. 5 years go for the renewal, it is a lot of money, which gives them a greater capacity to take greater risks, work, work with greater risk, and he is also a member of the National Academy and wasone of these people who graduated. high school at age 15 one of these phenomena and he is so religious about his naps that when he travels to give seminars at other schools he insists on having a nap time scheduled after lunch and in his office um you know in between the 12:30 and 1:00 p.m. he's sleeping, everyone knows this and I mention this because I think a lot of times people think the Nappers are the lazy ones, but his production is almost superhuman and he attributes a lot of that production to the nap, not just the release . -nap work that he is capable of doing, but his ability to handle so many ideas has a huge laboratory and that is just one example.

I think there are examples from the sport of sprinters taking naps on the side of the athletic field, so it seems like the ability to nap is also something worth considering because I think a lot of people who hear this think, Well, I can't take a nap, should I take a nap? Know? And can you teach yourself to take a nap? question, um, if one would want to explore napping, and um, it's something one should even consider doing if you don't have a propensity to take naps, you should avoid it if you want to try napping, how would one learn to take naps?, you just said. mention. before, going to bed, it is related to body temperature, body temperature, it is related to sleepiness and then as a third question, I promise I will repeat them if necessary.

As a third question, I'd like to have a little discussion about some of the pseudo napping states that, um, I'm certainly intrigued by, you know, for example, just lying down and I'm doing progressive body relaxation, things like Yoga Nidra, uh, deep rest without sleep, which is an acronym, just to do it. Sure what I was talking about, but it's very similar to Yoga Nidra, things like that, in other words, but just everyone should think about having an early to mid-afternoon protocol to reset your cognition and your body. We call it a nap, but is it like that?

It has to be a nap and if we are not good Nappers we should try it and if so how should we do it? Yeah, so IT your three questions first of all, if you're not a Napper Napper, you should start doing it, um, if you want. start doing it, how should you do it? and then the third is, is there any kind of substitute that you know of for a similar one, which would be these Li, these? I would love the phraseology you use, these lion states, do they imitate? Are they? different from that, how should we think about it?

The first thing I would say, point number one, if you're not a natural Napper, don't necessarily force yourself to be one as long as you get the sleep you feel you need at night. and you feel refreshed and restored during the day and you don't have that kind of post-renal crash to the point where you think I almost need to take a nap during the day. There is no pressure based on anything I've been telling you to get started. take a nap nor should there be any reason for you to start taking a nap, but let's say you want to test what would be the correct protocol to improve and increase the probability.

The best way to do this is to mimic the night as best you can, wherever you are. are if you can turn off the lights, make sure you can block, you know, curtains, blinds, if you can't do it completely and a lot of people won't be able to develop an IM mask procedure, so put on an IM mask, make sure you block out the noise with earplugs, you can use a sound machine if you want and we can talk about some kind of sound machine and if they are good or bad for sleeping and then you can go to bed, make sure you try to take off your shoes We take off and get under some type of blanket because Contex tells us so much to have something wrapped around us called a blanket or duvet than to do it without it, if you're not a natural Napper, it can help you again, as some people will say.

I can just put my feet up on my desk, sit in my reclining chair at the office and I can fall asleep. That's great, but if you're not a natural person I'm just trying to tell you things that increase the likelihood of that happening and then put the alarm. I like your idea of ​​making sure that if you fall asleep you don't accidentally fall asleep. too long and then you're just miserable, so mimic the conditions you're trying to get that you would normally have at night, which will increase the likelihood of masking the noise mask the light, take off your shoes, wrap yourself in some kind of blanket having it wrap around you is probably the best and then time it based on this kind of post-practice fall, you'll know for yourself that everyone's been a victim of it, you know.

It's usually around 3 or 4 p.m. m. that I start to feel this descent or is it around 1 p.m. try to match it accordingly, so those are the first ones. I think two questions you shouldn't necessarily do if you want and I usually don't. How can you do it? The final point, I think is fascinating, what these alternatives are. states of conscious brain activity, the most obvious being when we are awake and when we are asleep, those are the two most dramatic changes in consciousness that we experience daily without anesthesia. Like you, I'm very fascinated by this kind of both meditative states or these linear states, I think at some point you and I should collaborate and we should do some work and really analyze this, but the reason I find this interesting is because I'm going to assume that you are having dream-like states, but you are not completely asleep, how would you define a dream-like state?

What we have learned is that your brain, as it sleeps, is not en masse, it is not as if your entire brain is asleep. Different territories of your brain can sleep in different ways. and what we've also known and there's some argument is that even individual brain cells seem to have a period where they go into sleep and these individual neurons will start to show what look like these beautiful, big, powerful, deep, slow waves in terms. from your activation rate to I mention this because if that means your brain can be in local sleep instead of global sleep, if you're in global sleep, you're out like a light, you're asleep, but maybe these Lial States La The reason they provide these benefits is because you are still awake, not in global sleep, so if you are in global sleep, you are asleep but you are awake, so you are not in global sleep, but you may be now. you are having a local dream using a special mode.

In my lab, we can apply dozens, maybe hundreds, of electrodes all over your head and we can map the different places where your brain sleeps at a much higher resolution, rather than a 480 DPI movie on YouTube. Now I'm in 4K resolution. I can really dismantle what's going on analytically in your brain. I'm going to guess that when you enter these states and report that you come out of those states, I'm going to ask you on a scale of 1 to 10, how would you rate this as an experience based on your common experience? The greater the intensity of the Lial buff and the state he experienced, I'm going to predict is directly related to the extent of this deep local slowness, not remote. wave dream that is happening, you are still awake, but some parts of your brain for maybe seconds or even tens of seconds when I go to bed will oscillate in what looks like slow wave sleep, deep sleep states and, if everything I could look at that part of your brain and that little group of electrodes and someone told me if this person is awake or asleep.

I would say that they are asleep, they are in a deep sleep, but then if they slowly reveal and rewind and show me the rest of the brain and what it is doing. I would say, oh my God, no, this person must be awake, but that local territory, that district up there in their brain was having a slow wave dream. I think that's what I was able to find and that may predict some of the benefits that you get, some of the energetic productivity benefits. By the way, I should point out that with all this nap fuss, NASA discovered this in the 1980s, they were looking for ways to optimize their astronauts because when you're in orbit, depending on the orbit you're in, you're spinning. around the planet maybe 10 and 20 times every 24 hours, so you're seeing 10 to 20 sunsets and sunrises, so your sleep is a total disaster and you can safely check almost everything in terms of technology, but The only weak link in a space mission is something called a human, which is where errors typically occur, so how do you risk human error in space?

Because if you make a mistake up there. I mean, on the ground, it's not very good, it's kind of catastrophic, you can try to optimize their ability to sleep and their ability to maintain focus, alertness and productivity, and what they found was that these naps produced almost a 20% increase in short naps. increase in their alertness and almost a 50% increase in their task productivity and was so powerful that it translated to NASA ground employees on the ground and became what became known as the nap culture. NASA and from then on we had what we called power naaps Power naaps by the way, why are they called power naaps?

And you think well just because it gives me energy. It's a good idea, but it's wrong. It has a very specific story, a fascinating one. Two legends in my field. David Dingis, uh and. Mark Rose were kindly looking at how to instigate risk mitigation not in astronauts but in pilots doing long-haul flights because the most dangerous aspect of a long-haul flight is when you land and that's when you can sometimes have these things called catastrophic hole loss, which is a euphemistic phrase for a terrible plane crash and they were trying to say how you could use napping strategically to risk that and improve your alertness and they asked a very interesting question if you can just take a nap during a certain time. period of time because they have to be working on the plane the rest of the time, when should I place that nap?

Should I do it at the beginning of the long call flight in the middle or towards the end and most people would bet? like they did, I think it's best to put it at the end when you're really starting to struggle to get that boost and then you wake up, you're not asleep in OA because it's been short and then you're energized to land. They didn't discover that they found the most optimal time to nap was at the beginning of that long-haul flight and it sustained them for the rest of the flight. They now took their findings to the FAA, which was funding the work, and to Federal Aviation.

Authority here in the United States and they said we have some excellent findings and we think we should implement this and we would like to use a term to help pilots understand this and it is called prophylactic napping and of course there was a lot of laughter throughout the la room maybe inappropriate and they just said look, you have to understand our pilots, the alpha male types that you already know, and if you're starting to say that you need NAB prophylactically, it's not going to be adopted, that's a noggo, like that They looked around. the room because it's an alpha male culture, it's a mostly male culture at that time, they said what could we and there's a lot of beard stroking and they said, I got it, power, naps, it has to be about power, and that's where if Have you ever wondered where the term power naps comes from?

It's not because it increases your power and it does it and it increases it again. It's because there was laughter at that time of prophylactic naps. I would like to take a quick break and thank our sponsor. eight sleep eight sleep ago Smart Cooling Mattress Covers Sleep Tracking and Heating Capability Many times in this podcast we discuss how to fall asleep and stay deeply asleep your body temperature actually needs to drop by 1-3°C and to wake up Feel refreshed and full of energy to the maximum Your body temperature needs to increase between 1 and 3 °C. Eight hours of sleep makes it very easy to control the temperature of your sleeping environment, so it's easy to fall asleep, stay asleep, and wake up feeling refreshed.

I started to sleep. I bought an eight-seater

matt

ress cover several years ago and it has completely and positively transformed my sleep so much that when I travel to hotels or Airbnbs I really miss my eight-seater

matt

ress. I have even sent my eight places to hotels that I have stayed at home because it improves my sleep a lot. If you want to try Eightsleep, you can visit 8sleep.com Huberman to save $150 on their Pod 3 coverage. Eight Sleep currently ships to the US, Canada, UK, select EU countries, and Australia. Again, I'm 8sleep.com SL Huberman. The names of things fascinate me, especially in the health and wellness landscape.

Also and that is one of the reasons why I have become a real fan and practitioner of Yoga Nidra, which I believe translates to yoga. Sleep, which is the process of lying down for aperiod of 30 to 60 minutes. Progressive relaxation. These are scripts that are easily available as it is an ancient practice in India that is meant to restore mental and physical Vig. Vigor by placing one in one of these Lial States, um and I have great respect for the uh ner tradition, but sometimes the names are a separator, so people who listen to Yoga Nidra think oh, it must be yoga movement and that is, of course.

It's not true or they think there must be some mystical component to it, which isn't necessarily true, sometimes they include intentions and things like that, but often they don't, which is why I coin this phrase, um uh, deep rest without sleep, which essentially keeps the critical components of Yoga Nidra, but it doesn't include intentions and has shorter protocols of 10 or 20 minutes, so it would be a lot of fun and I think it's very interesting for us to do that project to explore what brains are. Activation states or deactivation states, as the case may be, in these non-traditional or lial state practices now along the lines of the power nap specifically and the naming of the power nap.

I think it's more than just a simple anecdote because I think it's very important for people to understand that these protocols, these tools that NASA and the laboratories have developed, often have other purposes, but they translate into a broader kind of meaning and what I'm listening to and what I'm listening to. I'm starting to integrate how we have the conversation today is that it seems like there is a very good reason to ex, at least explore basic sleep, for non-nappers to really think about whether or not they would like to explore napping like you. I mentioned that it's not necessary and then for people who are already napping to really think about the placement of that nap within the day and the duration of that nap, what you told us a few moments ago suggests that you should be doing or Anyone who is taking naps or entering these Lial States like nsdr might want to change them a little bit before the period where they first get sleepy to take that nap, is that right?

I mean, so, for example, should I do like my colleague and You know, finish lunch and go to bed for 10 to 15 minutes instead of waiting until 2 or 3 p.m. It's that something that could make a significant difference, I think it could and I think it really depends on how difficult it is for you to sleep at night, if it becomes later when you nap, if your sleep becomes any. It's harder to start it at night or maybe you don't have any trouble falling asleep, but for some reason when I look back now I'm starting to wake up more during the night and partly it's not just that if you nap .

At the end of the day you have difficulty falling asleep, it is possible that the other consequence that can happen and that is not mutually exclusive is that you do not stay as deep as sleep and your sleep is more fragile in that sense, so the probability that you will wake up because because you napped so late in the day is highest in the middle of the night and then when you wake up like many of us do and go to the bathroom or it's perfectly natural, but the speed at which you can getting back to sleep is compromised because you've gotten rid of some of that sleepiness through napping and there's not much that's going to get you back to sleep after you've woken up, so I would just say if you're seeing that pattern of the later you nap , if you do and again, there is no reason you need to take a nap only if you choose to take a nap, if that is the case then consider not necessarily skipping the nap which may not be necessary just bring it back before, take it after from lunch, see how things work, do the experiment and when you do it, make sure you do what I would describe as the onof on experiment, which is where you're taking a nap like you normally do and maybe you've noticed some problems with your sleep then do it so it's kind of an on and off phase so change your nap protocol and move it earlier so now you've turned off your standard protocol and I've moved on to something different so you're on your standard protocol and then you get it out and when you get it out it means you go to an earlier nap and you're like, God, things seem to be better, maybe he had something there and he seems to get better okay, but I don't trust that because maybe it's just an effect placebo that you listen to some boring British tones and convince yourself that maybe that would work and now, instead, after about two weeks of doing it. that and things have improved go back to your original schedule go back to your original protocol I'm not so interested in the fact that things improved when we changed it.

I'm interested in the question: do things get worse when we stop it? and so when we stop the intervention if Things got worse again now. I'm believing it a lot more, so just as advice if you're a self-manipulator and you don't have to do that, but if you're an idiot like me and a scientist and you. I want to do it with this rigor of the city, that's the way I would suggest doing it. I don't think it's stupid at all. I think it's systematic and what you just described is a negative control and positive control experiment, so it's you.

You're a scientist through and through, are there people who should avoid naps altogether? You know, I've heard about you, you know, older people, people with certain conditions, you know, I can't imagine which one, but I'm sure they will tell us that for those for whom napping is harmful to their health, I think it's a very interesting question. because the strongest evidence goes back to what we've mentioned before, which is insomnia and really the recommendation is just to avoid naps and what's problematic. about insomnia when you're having such a hard time sleeping at night and you're just dragging through the day, it's miserable and you know it, I'm very protective of my sleep, for the most part I sleep pretty well, but See I'm not immune to the whims of the dream.

I have had two attacks of insomnia throughout my life. Both have been what we call reactive insomnia, reactive to an event or something happening and I know how desperate and hungry you are. to sleep and if this happens week after week, month after month, I will do anything to sleep when I can and therefore the temptation to take a nap when you suffer from insomnia is much greater and therefore the advice is much more difficult to adopt. but believe me, that's one of the components that we have in the psychological treatment group that we use for insomnia, which is called cognitive behavioral therapy for insomnia or cbti for short and you can look it up or on my own podcast.

I did a six-part series on insomnia, so I would say try to backtrack on that circumstance, but you mentioned another example which is aging. I think the evidence is a little less causal, so you should be more cautious about recommending absence like I was with insomnia than abstaining from napping, but now the data has become pretty solid: when you get past 65 and you look at napping behavior in large epidemiological studies and you say, is there a positive benefit in aging to taking naps or is there no benefit at all? And they looked at it because they thought well that maybe based on the work in healthy adults that I've described it would be good for older adults, not only did they find that it wasn't good, they found that it was detrimental that napping in older adults predicted worse health outcomes. and it also seemed to predict a higher chance of early mortality, so at this point we're thinking well, how does that fit with everything you've been telling us?

This notion of poor nighttime sleep probably doesn't necessarily mean that daytime napping is bad for older adults, but rather that napping reflects a problem with older adults' nighttime sleep and, as we age, It's something I didn't mention during development. was that yes, we get this kind of 4 to 1 State Lael ratio of one part REM sleep, four parts non-rem sleep in our 7 to 9 hours and I described these changes in rem early in development. I didn't mention two things about non-rem. slow wave activity first as we reach adolescence and change our type of sleep schedule where we want to go to bed later and wake up later, that's biologically determined, it's not teenagers' fault, something happens with their Deep sleep, however, your deep sleep begins. to perform a different or different action in the brain than REM sleep did when you were a baby.

I said that during childhood we have large amounts of REM sleep and we were growing syap Genesis synapses and connecting all these new territories, all these new neighborhoods. with fiber optic cable, but let's say you've run the experiment for many years into the teens of those neighborhoods and you've been measuring the bandwidth consumption of each individual home and you've started to realize that you wanted to create a big spread. through the brain and then I'll let the experience of the next few years tell me which parts of the brain seem to enjoy that high bandwidth and which parts don't seem to use it much and as we move towards During our adolescence we go through something called synaptic pruning where the brain actually calls and removes trees from certain parts of the brain.

It appears that this change in slow waves of sleep that occurs around these adolescent years is performing the final act of cortical maturation. which is shrinking the synapses and fine-tuning the brain so that you have this beautiful efficiency and now you've reduced some of the bandwidth from some of those neighborhoods because they just don't use it much and you can move it around. In the territories that require more bandwidth and network, the brain is reduced, but its efficiency has improved in the sense that those regions that need it and are working hard based on what we believe this organism has been doing in the past, you know, 13 years, that's where we should place our bets, but as we move into old age and this will come back to the topic of naps, don't worry, stay with me here, folks, the reason is that as We age, our sleep deines but it's not just the decline in sleep deep sleep declines more dramatically and we all think of aging from the perspective of the brain as a cognitive decline in which our learning and memory abilities begin to fade and decrease and they do, but I would say that a physiological signature of aging means that your sleep gets worse and particularly your deep sleep.

What's perhaps concerning for people listening to this right now is that that decline in deep sleep doesn't start to happen in your 60s or 50s or even in your 40s, we can start to improve. that big decline in sleep starts in your mid-30s and then it just slows down and by age 50 it's down to about 50% of the deep non-rem sleep you had when you were 17 or 18 by age 65 or older o Certainly, At age 75, the deep sleep you had when you were 17 or 18 has dropped to about 5%, which is a surprising decrease. What that means goes back to the first episode where we talked about the four macros of good sleep quantity and quality. synchronization and regularity one of the measures of quality that I described to you was this electric quality of deep sleep.

The other measure of sleep quality that I talked about was how consolidated and consistent your sleep is versus how fragmented your sleep is, the measure of sleep quality. It's markedly compromised as we get older, we wake up a lot more times, our sleep is a lot more fragmented and therefore our sleep efficiency is worse and we have this huge decline in our deep non-restful sleep, so it's not wonder, then, when When you are awake during the day as an older adult, your quality of sleep is so compromised at that stage that you may try to compensate for it by taking a nap, but that compromised quality of sleep that you have at night is probably the reason why the one where you start to get sick.

What's more, you have a higher chance of getting sick and sick and why you also probably have a higher risk of premature mortality. In other words, it is the poor quality of nighttime sleep that leads to this behavior we call daytime napping in older adults. indirectly suggesting, oh my goodness, that daytime naps are bad and cause these problems, when in reality it's that daytime naps are an indicator of bad sleep that occurs at night and it's actually bad sleep that occurs during the night which is most directly related to concerns about health and mortality in older adults, so I think right now as a field I'm still open to the evidence that taking a nap for some reason that we just don't understand is currently problematic and causally predicts poorer health and shorter life expectancy.

In older adults, I think the best evidence we have right now is that it's really about poor nighttime sleep quality and so we shouldn't necessarily jump to recommendations that all older adults should stop sleeping. take a snap. I think we needmore evidence and I'm open to both sides of that, let's talk about caffeine. I have heard the term ter. Is it napine? Yes, I think it refers to a practice of drinking some caffeine, then going to bed for a nap, and then supposedly waking up feeling better. It refreshed my understanding and you will tell us more, of course, that caffeine is indeed an antagonist of adenosine, although it is a competitive agonist and you will explain to me, I'm sure, and taking a nap, as you mentioned before, takes some of the pressure off of sleep. . uh it clears out some of that adenosine that's built up, which sounds great, but as you mentioned earlier, there's also a warning there, the warning label on both of those things should be that having enough adenosine built up in your brain is one of the ways in which the ones where you feel sleepy at night and you fall asleep and stay asleep yeah, so what's the history of caffeine?

How does it work to make us feel more alert? And what is the fundamental reason for nappuccino? Caffeine is a very interesting compound in relation to sleep and wakefulness, obviously everyone knows that caffeine can help you stay awake, it is no coincidence that those two words you used about these chemical compounds, caffeine and adenosine, sound Likewise, it is because the receptor or receptor systems that caffeine targets in your brain are the adenosine receptors and you think well. Matt was telling me that the more adenosine you build up, in other words, the more adenosine attaches to those adenosine receptors in your brain, the sleepier you feel and I'm telling you, caffeine works on those same receptors, that doesn't make sense.

Caffeine, if it works on those same receptors, should increase your sleepiness, it doesn't, because when it binds to those adenosine receptors, those welcome sites in the brain. it just locks them, it doesn't turn them off or on, it just locks them, so think of it almost a little bit like a room that's full of chairs and at some point these adenosine, which is a collection of people with name badges. of adenosine, normally they would like to come in and start sitting in those seats that are the adenosine receptors and as they sit in those seats, it generates this signal of sleepiness and caffeine, which is another group of people with caffeine badges . they run into the room and they start hijacking the seats and they start sitting on them and all of a sudden adenosine can't find any seats to sit on so your brain is still flooding that room with adenosine so adenosine still It is accumulating. but the reason you no longer feel sleepy when you've had a caffeine shot is because the caffeine goes into overdrive, locks onto the receptors, and has essentially hit the mute button on your drowsiness, so now your brain was thinking, God. mine.

I've been awake for about 13 or 14 hours. I'm starting to feel it. I'm going to have a quick shot of espresso and you understand you're thinking, wait a second, you know, 20 or 30 minutes later, no. You no longer feel tied down why isn't it because the caffeine came in and cleared out the adenosine, the caffeine didn't come in and blocked the sights, but the adenosine is still building up and then at some point the caffeine gets worse and so you don't you're just going back to the same adenosine denin level you had 2 hours ago it's that plus the extra 2 hours of adenosine that's been building up and what you experience is something called a caffeine crash and now you need even more caffeine not just to get you back to where you were, but to recover from the accident you had and continue with caffeine in relation to the caffeinated nap, although napino is relevant because of its timing, caffeine has an instigating action of about uh 12, 14 to 17 minutes, so when you come in the morning and you have your first cup of coffee and within the first four or five minutes you say, I just feel better.

I just had a couple sips. I've had half a cup of coffee and I already feel better. I just needed that if it's within the first five minutes that you're experiencing, it has nothing to do with caffeine because the peak plasma concentration of caffeine isn't going to hit you until you know 12 to 12 minutes. 17 minutes, so why do you feel better? Something is Placebo because you smell the coffee and you associate it with the L. It's not really that, or or um, when you say Placebo, I also wonder if it's possible that it's a conditioned effect or not.

You know it as something Pavlovian because the smell of the coffee, the taste of the coffee, the hum of the machine, entering the coffee and asking for it from the barista also creates an anticipatory excitement like here, the state of alertness is arriving and in that anticipation there is its own form of alert status. I think that's certainly an important component. The other component, though, if you look at the data, is that it has nothing to do with the caffeine at that time, it's the temperature that most people take. Warm caffeine, whether it's tea or coffee or maybe it's something else Andrew Hubman would drink, but a lot of people have been drinking since he was 5 years old.

I don't know if he should have been drinking yerbamate caffeine so young maybe. Even at four years old there is a photo of me on my grandfather's lap drinking mate half of my family is Argentine and um so I drank caffeine from a very young age this brain developed in a millu with caffeine this explains a lot of things about what I have known about you during these no I'm joking then but we have to talk later no so the interesting thing about that is the temperature and I told you in the first episode that we need to cool down to stay asleep but initially we need to warm up to fall asleep because Warming up at that time, I told them, is warming up in the periphery, a warming up to cool down and fall asleep, so we need to warm up to cool down and then fall asleep. you need to stay cool to stay asleep and then you need to warm up to wake up, warming up to cool down and falling asleep is not warming in the deep center of your body, it's about warming your hands, feet and head to dissipate the heat, so warm the outer surfaces to cool the inner core to fall asleep but then I told you that you have to warm yourself to wake up and when we drink a hot drink in the morning usually with caffeine the change in your core body temperature can occur in a few minutes , so the initial benefit that you get from your morning cup of hot coffee or hot tea is the temperature rise and then you get this beautiful second boost from the caffeine itself and that caffeine can then sustain you for a longer period of time long, so we mentioned this problem with naps that even 25 or 30 minutes into a nap you wake up with that kind of grogginess that is sleep inertia and what if I could give you the benefits of a nap and have you came out of a nap with zero sleep inertia?

And that's what some people started thinking smartly: What if you could look at the optimal nap time, maybe 20 minutes, and think about the time when the peak plasma concentration of caffeine emerges and I told you it really starts. It starts up at around 17 minutes and is in full swing at 20. What if you were creative? I'm going to avoid saying idiotic enough but creative enough to get into bed right before turning off the light. afternoon nap I take a sip of a quick espresso the light goes out I close my eyes eye mask earplugs and I'm going to fall asleep well because the caffeine is not going to kick in and for another 17 20 minutes maybe in its maximum threshold so now you fall asleep and you're going to fall asleep and if maybe you don't make it too big in terms of your service, the temperature change won't affect you in a negative way and then just like your alarm.

The clock is about to go off after 20 minutes, you are in the beautiful upward movement of plasma caffeine concentration and you are thrown out the other side with the benefits of the nap along with the benefits of caffeine, so you get your cake . and you can eat it too, you get the nap without the inertia of sleep and so this created what we call the caffeinated nap. I love nappuccino nappuccino um maybe I'll try it uh this is the first time I've ever heard the rationale and the fine

structure

of napuccino, but it makes sense, um, on a logical and mechanistic level.

I have to ask, is there anything besides caffeine and sleep that can remove adenosine? cold shower, clear adenosine, I mean, and I understand that there are a lot of competing mechanisms in the body, like presumably an increase in norepinephrine or adrenaline, or both, will affect the adenosine system. I once heard a great quote from a former member of the National Academy of Sciences, a brilliant guy, he said you know a drug is a substance that, when injected into an animal or a human being, produces a scientific publication, which which means that it is rare to find an article that does not see some effect of some medication especially during sleep, as I remember, if you put aspirin for REM sleep in PubMed, you will see some effect on REM sleep.

People take asper, almost any substance one takes will alter some characteristic of sleep. or awakened states if one is looking with a sufficiently fine instrument uh or is it an exaggeration no, I don't think it's an exaggeration and we return to the first episode where we describe the complexity of this incredible and beautiful physiological ballet without a doubt one of the recommendations that the People say what I receive this afternoon in this publication will decrease my alertness. What I can do? I say you could take a nap, but another way is to just go outside and walk.

Be physically active. Some of that has to do with the fact that we probably get some daylight and daylight can be an alertness stimulator, as long as you've told us and informed us, we also know that physical activity alone can increase the amount of endorphins and dorphins, which promote awakening, but none of those are really necessarily going to alter adenosine, they're just canceling out the adenosine that's still building up, it really seems to be for the most part, at least As far as I know, it is only sleep and particularly non-rem sleep that has the ability. or give the brain a chance to clear out that adenosine now, which might be interesting, I think it's two circumstances, one is when your brain becomes less metabolically active for another reason and I told you it's not fun, it's not like it's during a deep phase of non-relaxation. sleep that there is a special pulsating cleansing mechanism for adenosine, there is a cleansing system called the glymphatic system that removes the toxic metabolic byproducts of the waking day, waking in some ways is biochemically low level brain damage and sleep is a health salvation in that sense. um, but which is again humorous and goes too far, but makes it clear that the idea here, though, is that it's not that there's a special system that removes adenosine during deep, non-normal sleep, it's just that your brain It is less metabolic. active and therefore does not produce as much adenosine, so the natural mechanisms that always occur in the background to remove adenosine and break it down simply have the opportunity to do so as effectively as before, but you are no longer working against what contrary.

The tide that is rising adenosine now the rise in adenosine has dissipated because you are no longer metabolically active during deep sleep and you have the opportunity to clear it, all of which means that and that would mimic that, like anesthesia for example. My guess is that you probably get rid of some sleep pressure when you're under anesthesia. I also think that these Lial States, the deep rest without sleep, could be fascinating territory because at that point I'm going to guess and we'll be able to see with the e G and we might also be able to take some images depending on how you and I design the study to look at what changes in the brain in terms of its activation state, I guess if you put it into something like slow wave activity patterns, that means that those territories of the brain are metabolically less active and that allows the brain to dissipate adenosine, so from what you say, I don't think things like exercise or light necessarily change a level of Denine, they do give a good effect. alertness benefit for other reasons, but is there an alternative way to dissipate adenosine?

Yes, I think anything that mimics a metabolically non-active or less active brain could produce these beautiful benefits of adenosine. Thanks for that, this brings me to a question about the period immediately after waking up. the nocturnal sleep period. I've been touting the benefits of delaying caffeine intake for 90 to 120 minutes after waking up. There is a misconception. I think people ran with the ball, assuming I was ordering this. or think or suggest that everyone should do this and that is simply not the case. I actually wake up and hydrate and drink caffeine very close to waking up if I'm going to work out soon after, yes, which I do often, but I've experienced and I know others have experienced whether or not they're going to work out right away.They need caffeine to exercise for any reason.

I have heard that these people exist. I'm not such a mutant M that he delays his caffeine intake. 90 to 120 minutes in some cases can compensate for the afternoon slump. Now I want to be clear that some of that may be offsetting the consumption of more caffeine in the afternoon because by delaying the intake of caffeine in the morning then perhaps there is less incentive or requirement to drink caffeine in the afternoon and all of this plays a role. dominoes, as we'll talk more in the series, to sleep better at night because you're not ingesting caffeine close to bedtime, but you run the risk of going off on a huge tangent, this is what I would do.

I would like to know, based on what you just told us, if sleep and lower metabolic activity in certain regions of the brain can actually help reduce adenosine levels in the brain. One could imagine that waking up is a step function of OK, you know, let's say at um 5:45 a.m. someone is asleep and the adenosine is still being eliminated because they are asleep and then they wake up boom, does the adenosine elimination stop immediately for people who have that wrinkled face, grogginess, and wake up at 5:45 maybe? even as an alarm, although we don't suggest it, and they stagger into the kitchen and normally they would make their cup of coffee, but they are in a pseudo-sleep state, so it stands to reason that they are still eliminating the adenosine now, if they are going to drink caffeine right away, then as you pointed out, they will block those adenosine receptors and there will be a continued buildup of adenosine rather than a removal of adenosine, so this was part of it, not the whole thing.

This is one reason, but part of the reason to suggest that people at least explore delaying caffeine slightly and then there are things like increased cortisol and etc., but that kind of framework at least makes logical sense, that doesn't mean that would hold up in a randomized controlled trial, but since we're essentially talking about zero-risk protocols here, what's your take on that? I think it's good advice for people to test and it's good advice for two reasons, the first is what you kind of describe. By taking caffeine early and masking that adenosine also caffeine can make your brain more metabolically active, which means it will accumulate more adenosine throughout the day, which means drowsiness will come sooner, which means maybe that crash postprandial be It will be harder and you may need to self-medicate with more caffeine and so the vicious cycle continues, so I think that is something to keep in mind.

I think it's a hypothesis. I think the second hypothesis. I or the second reason I would recommend this is that if you've been using caffeine like that for a long period of time, you may also be masking the quality of your sleep because you wake up, you're immediately medicated with caffeine, and you're alert. you're awake and you're thinking well I'm looking back on my night I'm awake now after my caffeine and now is the important part of that sentence I'm awake now so there's nothing wrong with my dream it's true maybe it is maybe it is Maybe it's true No, if you're abstaining from caffeine and you have to go through the detox period, this won't be the right test right away, but do it for about two weeks and then at that point, once you're clear of detox and withdrawal now you're in a somewhat naïve state where you're drinking caffeine.

I'm telling you to stop consuming caffeine. You are taking it at 11:00 after waking up, say at 7:00 in the morning. At that time we have this nice clear window that has been constantly occurring between 7 and 11 in the morning and I'm going to ask you now if you feel rested, restored and renewed and if you can operate with cognitive insight and skill. In those early morning hours, don't forget that we have to get through the natural sleep and Heria period in the first 90 minutes, but after the first 90 minutes of waking up without caffeine, say at 900 a. m. in the morning. functioning well because if you're not and you still think you know what I don't feel restored by my dream I don't feel refreshed I want to then start asking you, let's take a look at your dream and see how we can get you to do it. a more refreshed state and by using caffeine first thing in the morning you don't give yourself the opportunity to test whether or not you subjectively feel that your sleep is of good quality now you don't need to do this forever, you can just do a test for a month and ask that question and if everything is clear after you're through withdrawal and you're past the first 90 minutes after waking up and you tell me now in this more naïve state with caffeine in the first few hours, I feel rested I feel refreshed I feel restored by my sleep then that's great we don't need to worry about your sleep so that's the second reason why I like it because it gives you a chance to test whether your sleep is good or not. quality or not, I should also point out from the way I mentioned that I changed my mind about caffeine and its use and this brings it up again because you said I made this suggestion and it was non-binary.

It's not dictatorial, you don't have to do it. I wasn't saying everyone should do it, and in fact, even I will know how to modify my schedule. If I do something in the morning, I'll just drink caffeine. Soon, if I don't do it, I'll stop. I walked out the door when I first published a book and was very dictatorial about it. Me and I were very cute, it was very binary, you know, the dream is absolute and it has to be this way and no other way. I wasn't pro-caffeine and I was telling people about the dangers and there are dangers to sleep and we can talk about that, but it was a little too harsh.

I've changed my mind for at least two reasons: first, that's not the way society works or people live, so there's nothing like technology saying to leave your phone out of the room for 2 hours before go to bed and don't check it for the first 4 hours because the Genie is out of the bottle, so the reason I changed my mind about caffeine This is because if you look at the data on caffeine, it's amazing to health. In almost every metric we can measure, drinking some degree of caffeine is beneficial. Now I knew it. There's a U-shaped function that once was you go through about three or four cups of coffee and then you start going in a downward direction and things aren't as good.

However, the contradiction was that I was telling people that caffeine is not good for sleep and, by the way, sleep is wonderful for Health conveys all these benefits that we have and will discuss in this series, but then you compare it to the caffeine and caffeine conveys many of the same health benefits, so how do you explain it well to Mr. Sleep Scientist if you look at the data? Very clearly, caffeine is not the benefit that most people get through a cup of coffee and the coffee bean is full, not only of caffeine, it contains a huge dose of antioxidants and due to our poor Western diets they were so absent. of these antioxidants the humble cup of coffee has been asked to carry the herculean weight of our antioxidant needs on its shoulders, so it is no wonder that it alone carries such a strong health signal because it provides you with this wonderful dose of antioxidants in addition to caffeine.

For example if you look at decaffeinated coffee you still get the antioxidants but now you don't get the caffeine and lo and behold you get a lot of the same health benefits, it's not the caffeine it's the coffee itself so I think It's a perfectly good reason to justify caffeine, but again, just like naps, the dose and timing create the poison. If you're not someone sensitive to caffeine, then, I would say, have a couple cups of caffeine and try to stay away from caffeine use. somewhere between 10 and 12 hours before going to bed, depending on your sensitivity and it is different between people and we know that it is genetic, there is a specific, what we call polymorphism, which simply means a variation in a particular gene and if you look at the variations in that it will predict whether you are someone who is very sensitive to caffeine or not very sensitive to caffeine and it all comes down to how quickly you can essentially metabolically eliminate that caffeine from the system, so if you know that is a very sensitive person I would probably say try to stay away maybe 12 to 14 hours if you are someone who is not that sensitive then maybe you could go to 8 hours the danger is for people who say look I'm one of those people what do you know?

I'm really not sensitive to caffeine at all and I can have an espresso with dinner and sleep well. I stay asleep well, so it's really not a problem for me. I would say that may be true, but the inherent danger here. it's that and we've done these studies if I give you a dose of let's say 200 300 400 milligrams of caffeine in the hours before bed, which would be a big cup of strong coffee or two espressos with dinner for some people. They may fall asleep and some people stay asleep but the amount of deep sleep they have is compromised, in fact it can reduce their deep sleep by up to 20% now the danger is that you wake up in the morning and there are no signs in your dream that said you had sleep problems because you are not aware of how much deep sleep you had, that is the reason why I think you know that sleep trackers can be helpful in some ways, but then you wake up and don't feel as refreshed and restored, but you don't remember having difficulty falling asleep or staying asleep, but now you find yourself drinking three cups of coffee to wake up in the morning instead of the usual two, and so the vicious cycle continues, and you also see.

We made an interesting interrelationship in a recent study we just published in Wall Street Traders. It's not just about caffeine consumption, it's also about alcohol consumption in the evenings. People who overmedicate themselves with caffeine during the day need something to calm them down at night and main. depressant agent and depressant not in the sense of psychiatric depression but in the sense of brain neural activity, depression is alcohol, so you get this classic cycle of stimulants and tranquilizers. I need my stimulants during the morning, my caffeine and I need my tranquilizers at night to make me drowsy and it's this really interesting trade-off that we saw in these Wall Street traders, so going back to the notion of caffeine, although I support it in terms of its health benefits, I think it's very, very clear, just keep in mind. of the dose and be aware of the timing of the dose, try not to exceed about three cups of coffee, understand your sensitivity, there are certain genetic tests if you really want to go nerdy that will tell you if you have this sensitivity or not, but you probably will .

I know this and therefore just say, "It's okay, I'm not that sensitive." You could probably spend 8 hours or as close to 8 hours before sleeping or 10 hours if you're very sensitive. 14 15 hours and limit it to one cup. So those are the ways that I would look at moderating caffeine and changing your mind about caffeine, which goes back to your point where you were saying I made this recommendation about caffeine. I want to make sure I modify it so people don't get confused. Certainly, I need it. make an amendment to my stance on caffeine, so thank you for letting me say that, that's a long and complicated way around it, but that helps a little bit, that helps, thank you very much for that addendum to the legislature okay, so we you talked about the power nap and you told us about the caffeinated nap, the so-called napino, yes, what are other types of naps that can be beneficial for sleep, wake and alertness cycles so that you can think about the nap with caffeine as an attempt to amplify it, a sort of nap plus, if you will, but to your question, the study that comes to mind was a brilliant piece of research herculean in its study design from a large sleep research group in Japan and they asked if the nap was okay.

It's good, the caffeinated nap may be a little better, but can we go further? So they designed a series of studies, they had five different experimental groups and they tried to basically create a stack, a stacking system that they had in the five groups that there were. a group without a nap, which is the control, then there was a nap group, then there was a nap plus caffeine group, then there was a nap, in addition, washing face and hands with cold water immediately after waking up. I'll be back to explain why we think it works. and then the final group was a group that was a nap more bright light and again, thank you, uh, offering this as a general public to you, Andrew Hubman, for your light revolution, so it was a bright light with 2,000 looks immediately afterwards, so they had five. groups again no nap group nap group nap more caffeine nap more cold hands and face wash nap more immediate bright light cold hands and face wash is interesting I told you before that there was this three-part story about the sleep equation and vigil you needwarm you up to cool you down to fall asleep keep you cool to stay asleep warm you up to wake up and I say warm up to wake you up but use cold water on your face and your hands don't forget that warm up when I say it in the morning is to warm up the central core of your body.

You reverse engineer what you did at night. I said heat to cool and fall asleep, so you heat the periphery to release blood from the core and you cool down. Well, the reason they used hand and face washing with cold water was because that's the vascular surface, it's the place where we can modulate the temperature pretty quickly. Cold water on the face and hands therefore caused vasoconstriction in the vessels and capillaries there. all wrinkled and forcing blood back to the center of the body, so the core body temperature increases a little. Now you also get a little adrenaline when you splash very cold water on your hands and face. there's some of that too, but that's the rationale, so what they found first was measuring different aspects of their cognition, their mood, and their sleepiness, those were the outcome measures to evaluate how these five experimental groups changed different and you can imagine what I mean this.

It's just that I don't think I would ever accept a study where I'm doing five nap groups all within one studio. It's amazing, so they did the no-nap group and then compared it to the no-nap group. The nap group got a wonderful benefit just like we described and they showed benefits in their alertness in their cognitive performance and they also showed a reduction in their sleepiness, so the number one point on the scoreboard for a nap then they made the nap plus caffeine and sure enough, you got an added benefit to that. that you already got from the nap now wasn't as big as the benefit from the nap, so adding caffeine gives you some nice benefits and I've used it before when I worked with the kind of professional athletes that we do. instigate these naps um these naps with caffeine when needed, so that gave them a nice benefit, but then when they looked at the nap plus the cold hand and face wash and the nap plus the bright light, those also added some to the benefit. from the nap now they didn't do it. do the sixth group, which is really what I'm going to do some hand gestures about, which is the full stack method of steps where they said, okay, you're going to take a nap plus caffeine, plus wash your hands and the face with cold water, plus bright light, but If you were to put them together, I think they're probably additive rather than just compensating for each other, meaning that if you really want to not just take a nap or one more nap, what would the nap be? of the Caffe. but in the nap plus plus version you can rely on this study and the protocol would be: you lie down in bed, you take your shot of espresso before turning on the light, you drink it, you go down, you set the alarm for 20 minutes, you wake up, the caffeine is kicking.

When you overcome inertia, you go right out there with cold hands, cold face, with cold water and then you immediately get daylight for 5 to 10 minutes outside and at that point you're really in a supercharged state, so that's if only because I know there will probably be some audience members who are willing to try this or really want to optimize it. Don't tell me what's good, give me the best, that's the only suggestion I would have based on that data. I love it and in fact what you just described could easily be carried over to the period after waking up from night sleep, although one wouldn't ingest caffeine before waking up for obvious reasons, but it would make sense to do so.

I wake up, obviously, getting sunlight in my eyes, splashing some cold water on my face or hands or taking a cold shower, diving into caffeine or delaying caffeine. I mean, it's essentially the same set of tools and I think it really points to the fact that the circadian rhythm, the clearance of adenosine, the modulation of temperature, and of course the way that they interact, are really the levers and the buttons to modulate wakefulness, yes, that's right, I think we've gone over this notion of naps, but there are ways that you can try to manipulate the nap system still and there are ways that you can manipulate it even more, but I like what you're saying because it just goes back to basics, let's get the nap talk out of the way. go back to the morning routine you are absolutely right and think about hot and cold water, I guess very few people when they go to bed wash their face and hands, maybe they probably don't wash with cold water before.

They go to bed, right, they're going to wash it with warm water, why don't they? And they just say, well, why would I splash cold water on my face? You know, it probably wakes me up. Have you ever thought about why he wakes up? One part of this is knowing the activation trigger, but the other part is thermal regulation and the opposite is what you want to do, if anything, warm your hands and your feet, and that's exactly what you've always done. You have always medicated your sleep onset by using warm water on your face and hands several times during today's discussion we talked about polyphasic sleep and the different types of polyphasic sleep that we cover I wouldn't say they are conventional, but re um conventional are some of the more esoteric or let's call them high performance Pol polyphasic uh strategies for sleeping, so we've talked about polyphasic sleep in the natural way that it occurs, which is during infancy and sleeping like a baby means that you're sleeping in a highly polyphasic way. , but probably around the late 1990s and 2000s, with the rise of the biohacker movement and quantified self-movement, there started to be a lot of talk online about this notion of polyphasic sleep and there's no longer us babies here, we're adults now , but we are participating in a pattern that is highly polyphasic.

Polyphasic sleep simply by definition again means that you have multiple phases of sleep within a 24 hour period. And there are different strategies, so the way polyphasic sleep in adults works is that you take the 24-hour period and think of it as a pie chart and then you start dividing that pie into these quadrants. When it comes to polyphasic sleep, the goal is to insert multiple phases of sleep. around the 24-hour clock rather than a single phase, but the thinness of those slices of the pie are very thin, leaving big, thick slices of wakefulness in the middle, the notion that if you were to just intersperse little soups of sleep in terms of these little thin slices of sleep, you can increase the amount of time you're awake and you can increase all the benefits of an awakening, so if you look there's a website, I think it's It's called polyphasic society and it's not a society scientific like psychological, American Psychological or Medical Association, American Medical Association or British Medicine, it's not one of those ratified certified scientific or medical societies, it's just a society that lives online, which is great. and they make claims to suggest that polyphasic sleep can improve aspects of your mood, can improve aspects of your productivity, perhaps can even improve aspects of your health.

I think sometimes there are claims that it can help with life expectancy and there are several different schedules. that they will describe to you and that you can discover about the polyphasic sleep that exists, the first one that people have probably heard of is called the Uberman schedule and by the way, there is no h at the beginning of that, it's just you. I know it is not this man sitting in front of me who has anything to do with this schedule and after discussing the data he will reaffirm that very fact, so there is something called the Everyman schedule and then there is the triphasic schedule and there are many different flavors of This, the differences between them are in how you divide that pie chart and how much you allocate to small thin slices of sleep versus longer periods of wakefulness and how many of those you insert, but they all follow the same pattern if you look at the literature, however, it didn't start with the biohacker movement.

The earliest description I can find in the human record comes from Time magazine, a 1943 issue, and it describes the protocol of a fantastic and interesting designer at the time, a guy called a book. He and Minster Fuller created a design principle and that design principle was called the daxian principle. The daxian principle was primarily used initially to construct unique building structures and utilizes this notion of different types of quasi-spoke that interconnect into a central axis that creates an identity of its own. -The support structure is the most obvious. Have you ever been in one of those geodesic domes and inside it's like a botanical garden and it's all tropical even though you're in, say, being in England, in London, and it's beautifully tropical inside? that structure that type of lattice structure that comes in part from its design This was the daxian principle and he escalated it to different things the daxian car the daxian house the daxian Dome was fascinating but I was not a fan of sleep and saw sleep as a a pretty significant waste of time when, like the rest of his Daxian principle, he could harness more efficiency from the system with less structure and here less sleep structure inserted into his 24 hour period, which is why he was the first to describe his schedule and it was called the Daxian polyphasic sleep program, so it may have been an earlier practice in the record, but it's the oldest I can find, so let's go back to polyphasic sleep's claims that it could improve, say, your state mood or your cognition or your productivity or your health, a group of scientists at Harvard, some of my former colleagues at Harvard, looked at all the literature on all the states that were polyphasic or tested this claim and the first thing they found was their claims of better cognition, productivity, mood, and health, they found no evidence to support that polyphasic sleep was helpful, then they turned the tables and said it could be harmful, and in fact, that's exactly what they found in the first place , the total amount of sleep you get. at any of those times is significantly reduced now, of course, that's the goal, the quality of sleep you get is miserable, the efficiency of sleep, even when you have these short periods of time, especially during waking hours, it's very poor, it's not a type of sleep, even short, that you would want to have Third, they found that it would reduce your amounts of REM sleep, so that was the first set of findings: your sleep is not better, at all case, it is significantly worse and then they began to discover that there were significant deficiencies. in many of those things, impairment in cognition, in judgment and decision making, impairment in mood, and some aspects of impairment in metabolic health, particularly glucose regulation, so when it comes to polyphasic sleep, sleeping like a baby if you're an adult seems like pretty reckless advice now, yeah, I mean, it probably goes along with eating baby food, drinking breast milk and um and uh, having someone else dress you and change you as an adult, probably not advisable, at least it doesn't seem to be supported. for the data and again I want to be very careful here and you are also very careful.

I'm not here necessarily to tell anyone absolutely how to live their life. I'm just a scientist and all I can do is give you the information. just as you do and then it's up to you to make the best decisions you want to make. All I would say is I hope as long as you don't hurt yourself or your health and you don't hurt others. people then and it makes you happy so I say whatever in life good luck I accept it I always say uh do what you want but know what you are doing and don't hurt yourself or anyone else can you understand me?

That shirt and I will be wearing it for five days until Tuesday, so in that sense, although I would say that the evidence would suggest that perhaps you are compromising your health and your well-being, but that is your voice of choice and I understand that, so again, I do not judge you. However, to the question of always and when you don't hurt other people here, I would say there is a pause of caution because what we know is that when you don't get enough sleep, I described all the health consequences in the In the first episode there are another danger here, which is car accidents and we describe these microsleeps that occur and why car accidents caused by drowsiness can be so catastrophic.

A very interesting study was carried out in which they observed people who slept less than 6 hours. of sleep for several nights and put them in a driving simulator and asked them what is the probability that you will have an accident or an off-road event and sleeping less than 6 hours a night resulted in a 30% increase in the risk of getting into in a car accident now, the AAA releases some data that shows that when you sleep 5 hours, I think it's something like two times three times more likely to suffer aaccident based on real data and then when you slept 4 hours it was about a 10 times greater risk, in other words the less and less sleep you get, it's not a linear increase in your risk of having a car accident, it's an exponential increase , so I bring this back to polyphasic sleep because I don't know you.

You know, think about that 30% study, let's not go to the extreme, just under 6 hours of sleep, if tonight you call a taxi and it turns out that two taxis showed up and outside your door I told you, look at one of these two, you can choose any of them. , but I will just tell you that one of these taxis is 30% more likely to have an accident compared to the other and it is this one on the right that you would like to choose. putting his wife and children on S is very obvious, so I raise that question just to keep in mind that no one would want to cause harm to another person for C to bear the harm of another person through his own actions on his shoulders for the rest. of your life is not something that I would want and it is not one that you would want, that is the only note of warning, but other than that, I would say that you know how to live life to the fullest, which brings us to the conclusion of another Incredible journey to the sleep landscape, especially in the different phases of monophasic, biphasic and polyphasic sleep, and naps and caffeine and all their interactions, these are very important topics at the level of concepts, the level of mechanisms and, as you have also described wonderfully at the level of protocols they are practical tools that people can apply, so thank you very much Matt for taking us even further on this journey.

I'll just remind people of episodes one and two of this series where U Matt is so generously providing information. about sleep for us are available and can be accessed via links in the subtitles of the show notes. These fill out other mechanisms and aspects of sleep and I am also particularly excited for the fourth installment of this series on the relationship between sleep. memory and creativity, incredibly important and relevant topics for everyone. I also want to note that I really appreciate you highlighting some of the developmental changes that occur with sleep. I often get questions about, you know, sleep in children, babies, and the elderly. adults, as well as all ages in between, and you've just built this incredible tapestry of information for people to think and act on if they want to, so thank you so much Matt and I'm looking forward to episode four, Andrew, thank you.

It is a great privilege and continues to be an absolute pleasure to be here with you. Thank you. Thank you for joining me on today's episode with Dr. Matthew Walker to learn more about Dr. Walker's research and learn more about his book and his social media. identifiers, check out the links in the subtitles of our show notes, if you're learning or enjoying this podcast, please subscribe to our YouTube channel, which is a great way to support us at no cost. Also, subscribe to the podcast on both Spotify and Apple and on both Spotify and Apple, you can leave us a fstar review.

Please also check out the sponsors at the beginning and throughout today's episode, that's the best way to support this podcast if you have any questions for me or comments about the podcast or topics. guests you would like me to feature on the Hubman Lab podcast, please post them in the YouTube comments section. I read all the comments on many episodes of the Hubman Lab podcast. We talk about supplements, although supplements are not necessary for everyone. Many people. get huge benefits from them for things like improving sleep for hormone support and for Focus for more information on the supplements discussed on the hubman LA podcast go live transcendental written by us that's Liv mous.com huberman if you do It is if it is not.

You already follow me on social networks. I'm Hubman Lab on all social media platforms, so it's Instagram , but much. of which is distinct from the content covered in the Hubman Lab podcast, so again it's Hubman Lab on all social media platforms. If you haven't already subscribed to our Neural Networks newsletter, our Neural Networks newsletter is a zero-cost newsletter that also provides podcast summaries. As protocol calls in the form of short 1-3 page PDFs that cover everything from neuroplasticity and sleep learning to deliberate cold exposure and deliberate heat exposure, we have a fundamental fitness protocol and much more, all of which again comes at completely zero cost to you.

Go to huberman lab.com go to the menu tab, scroll down to the newsletter and by providing your email you can subscribe. I want to point out that we do not share your email with anyone. Thank you once again for joining me in today's discussion about sleep. with Dr. Matthew Walker and last but not least, thank you for your interest in science.