Accelerate Learning & Increase Cognitive Capacity | Dr. Tommy Wood

There's a much more recent study that took again older adults and randomized them across three different groups. One was like a low intensity group. Another group basically did kind of zone two type work on a treadmill three times a week. And the third group did a high intensity interval training intervention, which is the Norwegian 4x4 protocol. So four minutes 85 to 95% of maximum heart rate, they had a three minute rest in their protocol. They did that four times over. That's three times a week. Three times a week for six months. That's pretty intense. But what they showed was that that high intensity interval training group, they improved their fitness just as well as the zone two group. Interestingly, but they had much better improvements in hippocampal function and maintenance of hippocampal structural and MRI scan. And they maintained that benefit for five years after the six month intervention. So they worked really hard for six months, but that benefit was maintained for a really long period of time. Welcome to the Huberman Lab podcast where we discuss science and science based tools for everyday life. I'm Andrew Huberman and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. My guest today is Dr. Tommy Wood. Dr. Tommy Wood is a medical doctor and neuroscience researcher at the University of Washington in Seattle. He is also the chief science officer of Better Brain, a company that provides free brain health coaching. Tommy is an expert in neuroplasticity and human performance and how science based protocols can be used to improve your focus, ability to learn and skill expression. His work applies to everyone, from the novice to the elite expert and for all kinds of skills, cognitive, language skills, athletic and creative endeavors. Today we discuss the brain states that favor learning and importantly how to get yourself into those states. We also discuss how to get the most from a learning session. For instance, how long that session should last, how many sessions to do per day, and perhaps most importantly, how to tune your mind and body to get better at learning. That's something we don't often hear in the context of learning in neuroplasticity. That our brain circuits for focusing and learning are also capable of plasticity, meaning you can literally get better at getting better. Today we discuss things like flow states and something called a clutch state, which is a seldom mentioned but critical brain state to accelerate learning and performance. In fact, a clutch state is the state that you want to seek to learn and perform at your best. We also discuss how different types of physical exercise from long slow cardio to brief high intensity cardio and different forms of resistance training each open the window for distinct types of neuroplasticity and learning. So this goes way beyond the general discussion about exercise improving your brain. We get really granular about exactly what types of things to do to improve your brain in specific ways. As a career neuroscientist who has worked on in taught neuroplasticity for decades now, it's rare that I encounter someone with as deep knowledge about the real science and application of learning and plasticity as Tommy has. He's also extremely unique because he has a ton of knowledge about new science-based protocols for plasticity. And he's also an athlete. We discuss that a little bit at the end as well. So today you will hear a lot of information that I am confident you have not heard on this podcast or anywhere else, frankly, about exercise, mental training, nutrition and supplementation, and much more. And how you can leverage each alone and in combination to learn new skills with accelerated speed, precision and durability over time. I should also mention that Tommy recently released a new book that he wrote entitled The Stimulated Mind, Future Proof Your Brain from Dimension and Stay Sharp at NEH. It's an excellent book if you're interested in following up on today's discussion and learning more about how you can make your brain better at NEH. Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is however part of my desire and effort to bring zero cost to consumer information about science and science-related tools to the general public. In keeping with that theme, today's episode does include sponsors. And now for my discussion with Dr. Tommy Wood. Dr. Tommy Wood, welcome. So amazing to be here. Thanks so much for having me. This is my favorite topic in the entire world. What is more interesting than neuroplasticity? Right? The brain is so interesting, but it's most interesting feature, in my opinion anyway, is that it can change itself. Essentially, that's its core most important function. If it can't do that, literally none of the other functions matter. You could argue. And it's something that we have to be able to do right until the end of our end of our lives. You have an eclectic research tapestry. Today, we're going to talk about neuroplasticity, what it is, what it isn't, how to access it for men for women, different ages. And you also are a high performance coach. You're also a competing natural strongman. Yeah. Yeah. So does that mean lifetime no gear? Lifetime, well, it's tested. Lifetime no gear for me personally, but it's a drug tested version of the strongman sport. So yeah, if you compete in natural strongman, then you get tested. Great. So we'll talk about that. I'll resist the temptation to talk about your two boxer props because I'm a dog lover. That's a different episode. Neuroplasticity. I know what it means to me. How do you conceptualize it? How do you think people should think about it in terms of wanting to learn things and not forget things? I essentially just think of it as the brain responding to inputs in order for us to then be able to better navigate and survive our environment. And that's why I think it's such a fundamental part of what the brain does. And essentially, every time you learn something, interact with something, remember something, the principles of neuroplasticity are engaged. You are making new synapses or strengthening synapses, weakening other synapses. A lot of people don't realize that particularly brain development, but then also the refining of functions in the brain, through neuroplasticity includes the pruning or removal of synapses, often we think about it's all about growth and new connections, but actually it also involves the refining or removal of other connections that aren't needed. That's a massive part of brain development in the first place. And this is a process that's essentially continuously ongoing. And you can think of it as primary role is so that you can navigate, survive the world around you and that's through learning skills, through remembering people and things in fact. And one of the things that's most interesting to me about neuroplasticity and the way we think about our brains over time is that I think people have conflated neurogenesis and neuroplasticity. So when we're thinking about brain development, we're thinking about then also brain function over with age and either cognitive decline or maintaining cognitive function, we thought that the adult brain was fixed, right? Or then it was fixed and then it lost function. And this goes all the way back to Kahal who said the adult brain is immutable, right? He told us that you got into adulthood, it finished developing and then it was kind of done. He then at other times also said that changes in the connections between neurons could explain learning. And so there he's talking about neuroplasticity, but we kind of got this idea that the brain was essentially fixed as an adult and then you know couldn't change anymore. But that can't be true because you still learn and remember things on a daily basis as an adult. One of the things that I think we've gotten confused about is the fact that the adult brain does not make new neurons in many places where I may be in ill-factory bulbs in the dental jar, so they have a campus. But compared to the rest of the brain, they're not really making new cells. And so because of that, we thought well we can't then grow and adapt or change our brains as adults. But just because we have a fixed number, relatively fixed number of cells, doesn't mean that we can't change the connections between those cells. And that's happening all the time and that is the main principle of neuroplasticity. Yeah, I like your definition in part because I agree with it. In part because it encapsulates a lot of things including helping to clear up this misconception that we generate new neurons. I think the attractiveness of the new neuron idea is just it's so sticky. And so we would all love to believe that. But maybe there's good reason why we don't add new neurons. Maybe it's not adaptive. Adding new elements to a circuit is maybe not the best way to change a brain circuit. I think people also like the idea that every organ in our body turns over its cells, that we're not the same person literally that we were. The brain is same cells you're born with, minus a bunch of them that die off as you pointed out. And thank you for mentioning pruning and the removal of connections as a fundamental aspect of plasticity in terms of motor skill learning. Let's say I decide I'm going to practice billiards. And I'm okay now hanging there. But let's say I want to get really good. As I learn and get better and better, can we reliably say that most of my improvement is the removal of inappropriate action and therefore synaptic connections? I don't know whether it's the majority you might know whether it's the majority but I think that this certainly you it requires both right. The either development or strengthening of new connections and then the removal of other connections that decrease accuracy say all that don't allow you to do the exact motion that you were intending to do. This like I said kind of goes all the way back to the development of motor skills say in childhood, right? The brain is kind of finished developing union neurons sometime around two or three years old, right? Beyond that point, you're actually primarily removing connections in order to refine functions based on the exposures that you have be they language, motor, social skills, which is what the brain is essentially developing during that time period. So then that continues throughout our entire lives. And I think that something that happens later in life, one of the reasons why we may lose function is because we stop giving the brain inputs to maintain a given function. Therefore, that pruning continues, right? I don't need to learn, know how to do this. So I'm going to refine that away. That's kind of the developmental theory of aging or part of the developmental theory of aging. So in that, you know, when you're learning a skill as an adult or anytime, a big part of refining that motor patterns that you're developing has to be the removal of connections that are, or you know, the down regulation of connections that aren't allowing you to do the skill that you want to do. If you were to tell people, look, you want to keep your brain as young as it can possibly be relative to your chronological age, you should what? Like it, so this is a general brain health question, but really I'm specifically asking about plasticity. And let's make it multiple choice. And then you can add things to it. You should exercise. So it can be multiple things. And then we'll talk about which types of exercise. You should continue to do the things that you already know how to do. And then third option, not mutually exclusive with the others, of course, is you should try to do new things that you can't already do. And I still toil with this when I look at the literature on neuroplasticity and aging, right? Like yes, user to lose it is true. But we're also told that novelty and trying things that we're not good at is an essential component of building out brain circuits, continuing to make them function better as we get older. So how do you how do you think about all of that? I'll partly answer your last question and then maybe give a framework for how I think about it. So when you look at a combination of epidemiological studies and intervention studies in older adults, or everything about maintaining cognitive function later in life, you definitely see that those who continue to engage in hobbies and activities that are cognitively engage or cognitively demanding. And that can be lectures that can be volunteering that can be reading crosswords, that kind of stuff. Those individuals tend to either have slowed rates of decline or better maintenance of function over time and or lower rates of dementia. That's of course observational, right? But that's usually people continuing to engage in the things that they've already been doing, right? They're holding on to what they've got. Holding on to what they've got by continuing to do that. Okay. Now, of course, it could partly be reverse causation because if you're maintaining function, then you will, you're more likely to continue to do the things that that you enjoy doing, right? So there's probably, it probably goes in both both directions. However, there's an increasing body of literature that shows that by engaging older adults in novel cognitive activities, you see improvements in function. So that can be language learning, that can be complex, like, quantitative movement or exercise. You see the same things with musical training, like people learning a new musical instrument or learning musical theory trying to identify different patterns in music. And you see in randomized control trials improvements, particularly in executive function, that seems to be most common across those different interventions, but you're seeing improvements in cognitive function with novel cognitive stimuli. There's a lot of recent trials that have also used types of brain training, things like the point to trial that was here in the US, maintain your brain, which is a massive online study done in Australia recently. And that's sort of broad cognitive training with like an online cognitive training platform. So again, it's, it's a new or novel intervention or exposure that seems to provide a stimulus that improves function. So I think both can be or do seem to be important. I'm excited to share with you that my book Protocols and Operating Manual for the Human Body is now available for pre-order and will be coming out in less than two months. It's my first book, and it's a reflection of decades of research, hundreds of conversations with leading scientists and medical doctors, and my own exploration of health, fitness and performance. Protocols is a straightforward to use manual for overcoming any number of different pain points you might have in terms of mental health, physical health and performance. And if you're already doing well with mental health, physical health and performance, it can make you that much better at any and all of those things. 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I ask what, for an example of maybe one or two of the things that were in that large scale trial from Australia, like just at a very top contour level, older adults, meaning 65 and older, are doing what? The maintainer brain study was actually who's sort of midlife kind of 50s and 60s mainly. And they actually had interventions across four different domains based on risk factors within that given individuals. So they had a dietary intervention. They had physical activity. They had progressive behavioral therapy for those who had the some potentially some mental health concerns. And then they had online brain training. There was something similar done in the point trial, which was in older adults now 60s and 70s. That was done here in the US. That was a replication of an older trial called the finger trial that was done in Finland. But what those guys did was something very similar. So it's a diet, exercise, monitoring and treating cardiovascular risk factors and then brain training. So what the brain training looks like, so that the point trial is a good example. They did, they used the platform called brainHQ. Which is an HQ. BrainHQ, which was developed based on the work of Mike Merzenich, like one of the Godfathers of learning and neuroplacicity, right? And they do various tasks, primarily focused on developing and maintaining processing speed. Some of that evidence goes all the way back to an older trial called active. There was done in the US in the 90s. It was still the biggest ever trial of like pure cognitive brain training. Again, in older adults, so 60s and 70s. There are three different training groups, the and then a control group. The training groups did memory training and kind of like, you know, nummonics, memory palaces, that kind of stuff to help them remember. There was reasoning training, which was kind of like looking, looking for patterns in numbers and letters. And then there was processing speed training where in this example is visual processing speed. So things flashed up on a screen in increasingly small increments. So it could be hundreds of milliseconds. And as you get better at doing it, that time gets shorter. And you have to remember what you saw and where you saw it on a screen. They just published a secondary analysis of the active trial that showed that those who did processing speed training with boost the sessions at one and three years had a significantly decreased risk of dementia 20 years later. And they've done some other studies showing that that kind of training improves co-allergic signaling in the full brain, which we know is susceptible to the processes of dementia. So in particular, it's this training to be able to improve either visual or auditory processing speed, which is not something that, you know, as you get older, you tend to not do activities that require you to process information quickly. Like driving is probably the main one. But you can do it in sports and music and other other scenarios, but if you're not doing those things, processing speed tends to drop off sometime around 60 years old. When you say, well, I say processing, usually processing, processing speed, are you talking about reaction time, improving reaction time, or pushing people to stay at the edge of reaction time? And when I say stay at the edge, I should clarify for people some task where if you go too fast, you make errors, if you go too slow, there's also a penalty. In this scenario, studies that look at these different functions over time, the biggest one looked at data that came from the implicit association test, people might have heard of, where you get, show these pictures of different things, and depending on how quickly you respond, it tells you something about your implicit thought processes. They took some of the data from that, this was published in one of the Nature Journals a few years ago. And what they showed was that you can separate out reaction time versus processing speed, because reaction time is a very, just the basic of response to a visual stimulus, whereas processing requires you is based on how quickly you can process and remember the information that you actually think. Actually, yeah. So what they showed in this study was that reaction time kind of slowly decreases on average in a population of, it was about 1.2 million people, slowly decreases in sort of like from about our 30s, and then maybe decreases even more once we get past about 60. Processing speed on average tended to be more stable until about 60 years old and then tends to drop off. So in what you're doing in these training modalities is you're being shown information for a very short period of time and then having to remember what it was you saw and where you saw it. So requires you to actually think and remember process the information rather than just like responding to a stimulus. So for people that want to jump to the okay, what do I do? Can we conclude, okay, if you like crossword puzzles, keep doing them, but do really hard ones for you. If you like lifting weights, continue to challenge yourself with those. If you like to run, push harder or should it be we shift domains? You like to lift and run? Great. Start swimming again. Andrew, I'm telling myself, I just noticed over time, it's such a cliche of aging, right? That you, one does tend to become more narrow, quote unquote, set in their ways. You like what you like. You don't want, but like we don't, you get busier, probably don't actually get busier, but you convince yourself, well, I'm doing these things and I do plenty of them. So, but I'm not doing these other things. Or for those of us, I think this is everybody, if they really ask themselves and answer honestly, you'd lift to hold onto your motor function and cognitive function as long as you can, maybe even improve it. Should we push ourselves to do something that's really far outside the box or maybe sort of current skill adjacent? So I think of those three categories. What do the data say? If you want the greatest effect for the minimum amount of time. Assuming you're still going to do all the stuff you normally do, you're going to add something else. Should it be something really different, slightly different, or just push harder in the thing you do? I think it's going to depend a little bit on what it is the things that you currently do, right? So like crosswords are a good example. Even if you're doing hard ones, if you look at the work of people like Gloria Mark, the things like crossword and Sudoku, they're less of like a true cognitive challenge, right? It almost has more of like a meditation, meditative like effect, right? Which can be a good thing, right? So you're focused, but not challenged really. Whereas if we're trying to build capacity, you need to spend some time doing something where you are both focused and challenged cognitively. So that can come from learning new skills, be they motor, language, social, and ideally as broad as possible, because you're going to get better overall stimulus as well as kind of like broader potential for transfer into other areas of day life. In reality, the narrowness of the response or the breadth of the response is proportional to the narrowness or the breadth of the stimulus, right? So you could get really good at one very specific thing or you could try and learn a new skill that requires the involves a wide variety of tasks. So I'll give, oh, like an example is learning a new ball sport, right? That is going to require multiple assets of motor skills, social skills. It's going to include both visual and auditory processing that's going to get faster and harder and harder the better you get. So something like that creates a much broader stimulus than if you get very good at one very specific brain training task on like one computer program, right? This is one of the main arguments against online or digital brain training is that you get very good at doing that one specific thing, but it doesn't transfer over to other areas of your life. So these broader, more complex, ultimately more human skills, probably give us much broader transfer as well as, you know, because of the multiple pathways or networks that are being activated. If my interpretation of what you said is correct, pick something hard, ideally pick something that's a bit outside or really outside your current skill set that involves motor and cognitive aspects, like maybe, and that's kind of tricky to find, right? I mean, with sport stuff, it feels motor and cognitive because you have to learn the rules of the game. You have to, in some cases, interact with others with cognitive stuff. The motor skills involved in writing or turning a page, they're not that significant, right? Even with a video game, I know video games can improve reaction time and visual search and things like that. Basically, your thumbs get real, real good. I actually went to a video game competition. They have teams, a kid that used to work for me. I was like, "What do you want?" "Have you got to end of your gift?" And he was like, "I really want to go to this video game championship." And the kids actually, who compete warm up their hands, the kids in the audience, like, have these styrofoam things, they clap so they don't make noise. So they, and it was the whole thing. Yeah. So I don't want to take anything away from the real sport. I discovered that is playing video games, but mostly what was moving was thumbs and fingers. Not a lot of large scale motor activity. So if you had to maybe throw out three or four things that are particularly potent plasticity inducers, what would those be? This definitely doesn't have to be super complicated. So the things that you mentioned earlier, so you could, you mentioned exercise and then skills, right? And so you could do those things separately, right? I would maybe again, to why aerobic and strength training do different things to different parts of the brain, right? So ideally, you do a little bit of both. If you don't feel super compelled to go and start a new sport, but you're getting these inputs from elsewhere. And so you would rather say learn a new language, right? Which we have some, which we have some good evidence for. Then that combination is great. But if you're thinking about some of the things that we have, very good evidence for that kind of hit multiple networks at the same time, dancing is probably number one. Learning a new dance. So lower was someone else. I'm sure we have joking, but some people dance on their own. Some people dance with someone else. So like dancing on your own in your living room, highly encouraged, right? It's a great form for this activity. It's fun. You know, of course, the best evidence is for ballroom and line dancing, which generally requires, and so the remet analysis of these interventions in older adults showing that ballroom and line dancing have the greatest effects on cognitive function. And so both of those require other people as well as learning, you know, various sets of movement. So you have skill learning, you have social interaction, and you have physical activity component. There's probably also the musical component where you have to listen for the timing of the music and those kinds of things that is its own skill set. So dancing has a large body evidence behind it. And then I think in the exercise realm, you've got all the sort of ball sports, board sports, team sports, I think skateboarding would be a great example as long as you are a helmet and don't hit your head too often. You know, most martial arts, again, as long as somebody's not punching you in the face too much. Sometimes like Brazilian Gigi too. Exactly. So like you're, there's a physical component. There's a complex motor skill component. Usually there's a social component. There's a, there's a lot of responding react to the environment or your opponent, right? So then talking about processing speed again. But then beyond that, there's some really interesting data on some other creative arts that do seem to have some effect on, you know, networks, stability and function in the brain, particularly the networks at the front of prior to network that we know is really important for like focus and attention. And its function does tend to decrease with age. So things like like creative or visual arts, some maybe some similar effects of learning are language. Again, similar effects from learning to play video games. Yes, of course there's no like big motor patterns involved, but you're having to do, you know, solve complex problems, you know, react quickly to a changing environment, that kind of stuff. So that's, you know, eight or nine different things that somebody could try. like eat just one of those. I think it's going to be a new skill, a new stimulus, often happens in a social environment. A number of different things happening at the same time. Any particular instruments? I don't think anybody's looked at instruments, like the difference in different instruments. So I would say, no, pick one that you would, that you feel motivated and interested to learn. Yeah, dancing by oneself has a lower shame question. Well, the shame question I think might be, might be important, right? There's the, you know, the discomfort of making mistakes and we know how critical that is for learning. And so like you're, I think some of that can be important too. But if you do it in a class, everybody else is a beginner, you're all doing it together. Maybe that adds a fun component because you can laugh at each other when you don't get it right. So a few years ago, I wrote a paper with my colleague Josh Turknet about this idea that potentially one of the reasons why we lose cognitive function as we get older is because we stop giving our brain novel inputs or complex inputs that help maintain function drive neuroplacicity. And I think one of the reasons that that happens is because adults hate being bad at things, right? You just like this thought, like you, you, you just imagined it, right? I'm in a dance class and I'm going to suck at dancing, right? I imagine that I'm going to take my wife to a tango class. There's something I've always wanted to do. But when I go in the first time, I imagine I'm going to be like Arnold Schwarzenegger and Jamie Lee Curtis in true lies. Do you ever see that movie? Anyway, so right at the beginning, they're like best buys and they're doing the tango at this, you know, like gangster's mansion or something. And it's like Helene's Rover. She grabs the rose from the table in her in her mouth. Like, I'm going to try that. I'm going to drop my wife and she's going to hit her. She's going to be mad at me and lots of people are going to see and I'm going to feel stupid, right? And so that's why we don't do those things. But it's so critical to driving those processes of neuroplacicity that we make those mistakes that we have to kind of let go of some of that that we feel as adults like we we think everybody expects us to be good at everything and the best at everything and you know, we shouldn't fail, we shouldn't make mistakes. But as you have covered many times, it's so critical to do that. And so I think acknowledging that shame component exists and leaning into it is going to be a really important part of trying to maintain this function at a time. A couple of quick anecdotes and then some encouragement to do the tango class. I'll start with tango. My grandparents on my Argentine side did tango until they're into their 80s. So it can be done, but they learned it rather young. And Tim Ferris as I recall, he talked about his look. He learned tango and then gets to the other point which is I want to talk about sex differences and results of experiments in plasticity. But when you dance, the sorts of dances that we're talking about. So it's also tango. Typically, this is, you know, traditionally the male leads years ago. I had a girlfriend who was really into salsa. So I went salsa dancing with her in the Bay Area one night. And it's a tricky thing if you're not skilled salsa dancer because basically you're taking your girlfriend to go dance with a bunch of men. And then you until you learn. So that it's there are conditions that make it harder, social conditions that make it harder for men to learn than women to learn particular types of dance. Unless as Tim did, he got a dance coach, a female dance coach to teach him how to lead. And then he learned how to lead. And then he was able to dance tango competitively. I think I have that right, Tim. They'll write me in the comments. But as I recall, that's the story. So there's that. Not that following is trivial. It requires some skill. But if the person, yeah, and traditionally the male can't lead, the whole thing, it doesn't work. Right. So I just made you more nervous about going to this class. But you should do it because I had a roommate when I was a postdoc. It was a neurology resident at UCSF and she would go do tango late at night. And she would come back a different person. And so this is like the other piece here is, you know, it seems that when we are trying something truly new, that involves interactions with other people and we go into that willingness to enter beginner's mind or whatever it is, embrace the shame. And as we start to get even just a little bit better at something, I mean, it almost seems like there's this kind of halo around the rest of our life. We go to work the next day differently. We interact with people differently. Like our nervous system is changed. What do you think that is? I mean, we could make up stories about chemicals and maybe we should, let me just get it likely to be true. But what do you think that is? That like general change in arousal, like you're sleeping better, you're more excited for the other things in life when you're trying to learn tango and you get just a little bit better. What is that? I don't think I would make up anything about chemicals. I think you could boil a lot of it down to, we like to be good at stuff. And we like to overcome things. Right? This is like this. This is like core needs to be challenged and then to overcome those challenges. And I think there's a lot of downstream effects of not doing that. And they could be related to mental health, they could also be related to physical health, because we could think about physical and cognitive or stress or psychological related challenges and the process of overcoming them. Because that's what really drives a lot of physical or mental psychological growth. And I think that's something that fundamentally is part of what we need on a daily basis. And so you did this thing that you were bad at and you got better at it. And you proved to yourself, hey, I'm capable, I'm able to overcome challenges, I'm able to engage and do difficult things. And I think the psychological benefits of that, you're just that process of engaging with the challenge of coming it, working hard to do that. I think that's just almost like a core psychological need that we have. And then that transfers to all these other things. Oh yeah, I can do these hard things. I'm going to do that other thing. I'm excited to try something else that's difficult. I'm excited to challenge myself again. And it needs to be something that feels meaningful, feels difficult enough that you have the ability to overcome with some dedicated practice or focus time working on it. If it's too hard, you can have the opposite effect. Like making something so difficult, somebody can't do it and they just fail again and again and again again. That can obviously have the opposite effect. But something that you know you can get better out, you know you can work on, you can see progress. I think all of that then has all these knock on the things. Hey, we could talk about flow for a second. You know, one of the most bastardized terms in neuroscience performance psychology and the rest. When Cheeksamahai talked about it initially, when he really defined the term, it was about being engaged in a process where you have a certain level of skill. But the thing you're trying to do is just beyond your skill level. So really striving a bit and that kind of general sense of well-being that can come from that. Nowadays, I think people assume flow is when you are able to do something in the absence of kind of feeling of effort. It's like you just, you get the magic power kind of thing, which is not what flow was originally intended to mean. I like to know how you think of this concept of flow. And whether or not it's even a meaningful term. And I, you know, I tip my hat to Stephen Kotler and others who have written about it and studied it and a great respect for Stephen and what he's done with the concept. And I think it's a meaningful concept, but I don't think we really know how to define it. And I think this is important in the context of plasticity because I think what we see in Harry Potter movies and sci-fi and you know, fight club and everything else is that suddenly we're just going to be endowed with these powers just because we want them in need them. And that is not how it works. So is flow an expression of skill or is it the striving to attain a skill? I think of flow as the maximal expression of a complex learned skill. Like you said, you're right at the edge of your capabilities. You're still managing to maintain, maintain function, whatever skill it is, your performing hat. The thing that really frustrates me is that because of that or you know, some version of their definition of flow, people like, well, I've always got to search for flow. Like everything happens in flow and like we need to be in flow all the time which doesn't make any sense to me whatsoever. There's two different parts of this. So one is that people assume that for optimal performance, you need to be in flow. That is not true. Flow is one version of your of being able to, you know, perform at the best of your abilities. Do we think about this in terms of sports performance? There might be broadly two states associated with top level performance. One is flow states. The other is clutch states. And so a clutch state, you are still at the optimal level of arousal, right? If you think about the arousal curve and performance which we can come back to. But so at the optimal level of arousal which is required for you to perform the skill that you're trying to perform. But when you're in a clutch state, it still feels like hard work. Right? So like there are, you could talk to any athlete about a time that they performed well, they won, they did the best of their abilities. But it was hard cognitive work, it was hard physical work, it was a slog. But they still managed to perform well. That's a clutch state. And people can perform at the best of their abilities in clutch states. And you know, even though they're not in flow, it's not all coming to them easily right? it requires them to really focus and work hard to get the job done. And both of those are perfectly reasonable states in which to perform. And assuming that you have to be in flow to perform just isn't true if you look at how athletes perform in the moment. The other side of it is that some people have intimated that flow is required for learning, or like, "Optim what learning happens at flow is" doesn't make any sense, right? If we talked about making mistakes and errors and friction required for learning, that is not conducive to flow because it can be stressful, it can be frustrating. And sort of the other side of that is if flow is expressing your skill, if you want to get better at that skill, you have to work even further beyond your current capacities, which will move you out of flow, right? Because of the friction and the mistakes and the errors that come from that. So I think your flow is super interesting and I wouldn't pretend to be an expert in flow, but there are all these other states where learning happens, where performance happens, that aren't flow. And that's fine too, right? But sometimes it's hard and that's okay. I'm so glad you're here. I've been looking for this conversation for, well, since I started the podcast because I completely agree about flow and the misunderstanding of the concept of flow. I've never heard of a clutch state. Is that a term that you coined or something? No, no, in the sports psychology literature, that's what I haven't seen it. Because I'm very familiar with the neuroplasticity literature, but I've never heard of it. Maybe I'm just not up to date on my reading, but thank you for introducing clutch state, which is when one is performing well, but it's involving, and this is a term I did make up, sort of some limbic friction, like you have to push yourself, you're feeling constrained. It's that you're at that edge where there's real challenge. You're definitely not in flow. Fantastic clutch state. Everyone learn it, know it, embrace it, live there for some period of time in your life, across your lifespan, and you'll be better off. I mean that. Maybe we could drill into this a little bit more because several times on this podcast, or more, we've talked about the anterior mid-singulate cortex, the structure that maintain size and super-agers who take on hard things. This area of the brain that seems associated with tenacity, which when stimulated, people feel like an impending challenge. There's actually neurosurgery experiments done by Joe Parvizi at Stanford. People feel like, oh, there's an impending challenge. I'm going to lean into it. This is sounds more like the clutch state, then certainly, then flow state. So maybe the thing we need to embrace is the clutch state. It's pretty catchy. It's not quite as catchy as flow, but I like it because it has an element of like friction kind of written to it. You heard it first from Tommy Wood, folks, not me. A good friend who comes from the special operations community. We talked about performance years ago, and he said, well, there's unskilled, skilled mastery in virtuosity. Okay, cool. And he said virtuosity is when someone who has mastery, pushes out to an edge of effort where they're sort of inviting in the unknown. They don't quite know what they're going to do. Next, they have some semblance of an idea. Like they're not being haphazard. But there's an inviting in of the unknown, and they find themselves at a new level. I've probably mentioned this documentary four times in the last four episodes, but when Andy Stumpf, former tier one seal operator came on this podcast, former wing suitor, Red Bull hyperformist team come on here. He suggested a podcast that I'm now suggest. He suggested, excuse me, a documentary that I highly recommend, which is the Dark Wizard, which is about Dean Potter, who is a free climber, a free solo climber, turn wing suitor, et cetera. And you see in that documentary how somebody who's pushing to their edge and a little bit beyond where the consequences, the death consequence is able to access levels of skill that are like jaw dropping, I think, even to him. So does that make sense? Like is that sort of how you think about unskilled skilled mastery virtuosity? Do you think virtuosity is like where someone's like, all right, I've mastered this thing now put me in a situation where I'll put myself in a situation where I don't know what's going to happen. And maybe it'll all go wrong, but when it doesn't, new levels of performance emerge. As it's described that way, because you know, people might talk about virtuosos in a skill, just because like there's so much better than everybody else, right? But like that, that definition requires a specific scenario and moment of performance, right? So then that sounds a lot like how I would think about flow, right? And so like when you look at some of the classic descriptions from individuals who've been in that kind of level, so like there's one from, so I do a lot of work in formula one. So there's one from Edson Center where he's from who I'm sorry? Edson Center, the driver, the driver, center, yeah, center, excuse me, Edson Center, David Center, the podcast, he's the he's the virtuoso of performance and business and finance podcasting. Don't let any of your F1 loving friends hear that part of the podcast. I like Center. Edson Center, some people consider him to be the best formula one driver of all time. He died tragically in a crash. But there's this famous quote from him where he's driving in the monochrome pre. And basically what he describes is that he's like going faster and faster and faster and faster. He's like, this is beyond my capabilities. He's like, he doesn't feel like he's actually connected to doing the thing. It's just kind of like happening. It's exactly, like he's going seconds fast around the lap than anybody else. And so like that's kind of what, like he is so good, right? He achieved mastery. And in that moment, he's displaying virtuosity in that kind of definition. And so that feels like there's a lot of overlap there. Yeah, ever since seeing this dark wizard documentary, which I've watched twice all the way through, because as a mental health component, it's a brilliant and beautifully shot documentary recently released. I think about this virtuosity thing, like constantly. But I love this notion of the clutch date because it sounds to me that that's the state that we want to seek. And the assumption is that high performers are in this relaxed mellow state, but I'm guessing they spend a significant amount of time there and drilling the really boring stuff to make sure they can get there. Twilithar, but it's in her 80s world class choreographer. Sat in the chair that I'm in and described with the daily routine of her world class dancers, they go through the most basic drills every single day, but every iteration for hours upon hours upon hours before they begin, quote unquote, practice, right? Before they try and embrace the new performance piece, but over and over and over, often after multiple hours of morning exercise, I think we don't see all of that foundational work and that it needs to be maintained, which raises a question, do we always need to maintain, practice the fundamentals? Before I answer your question, I think there's another useful thing, just kind of to remember that relates to all of this from in athletes and sports, but on the training side, there's this general idea of thirds, right? A third of your sessions, training, learning, whatever it is, are going to feel great. You're going to feel really good, you're just going to get stuff, you know, immediately it's going to just come to you. A third will just be average, right? And a third is just going to suck and you just have to show up and get it done. Oh, this is all in the same day, or this week? No, just across the week, across the week, across months, across years, where this stuff unulates. And the main reason why I say that is because related to this sort of glorification of flow is this idea that these things should just like always come easily to us. But that's completely antithetical to the idea that we have to work hard and challenge ourselves in order to build capacity, drive neuroplacicity. So there's kind of this weird tension between what people are seeking versus what is actually just the part of the grind of getting better and over time. And sometimes it is a grind. And that's, you know, again, that's okay. It doesn't mean you're doing it wrong. Maybe it means you're doing it right. When you then think about maintaining the fundamentals, I think yes, but probably it's going to depend on the scenario that you're thinking about. Because sometimes the skill that you're performing, the fundamentals are kind of baked into that in some way. So it kind of depends on what the fundamentals really are. Maybe, you know, if it's, so I'm thinking about one specific study that was done in in pianists. So this is kind of related to the Ericsson studies in violinists, right. But this time they were looking at pianists. And so they had four groups. Older and younger. So the younger was like 20s and 30s, older were 50s and 60s, expert and amateur pianists. And so the experts came from German like music conservatories. And then they looked at sort of basic skills related to moving the fingers and other things that you would do playing the piano. And So there were very task-specific skills related to piano playing. And what they found was that the most important predictor of how well somebody performed at those piano-specific skills was not their age, it was how much they practice. So it's just that getting those reps in helps you maintain those basic functions. And maybe when you're playing very complex piano pieces, you're encompassing all those fundamentals anyway. You don't need to do your scales every day because some of that stuff is built in. But you will also see people as they warm up, say, maybe they will do scales and things, because that's part of the warm-up. Maybe that's routine. This is me getting in the mode of playing complex piece, but then maybe some of it is just helping to maintain those fundamental skills. I'd like to take a quick break and acknowledge our sponsor, AG1. AG1 is a vitamin mineral probiotic drink that also includes prebiotics and adaptogens. I discovered AG1 way back in 2012, long before I ever had a podcast, and I've been taking it every day since. 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Again, go to drinkag1.com/huberman to get a free bottle of the new Omega 3 Coenzyme Q10 with your first AG1 subscription. So it now is your opportunity to kill the 10,000 hours, man. I know other people have attempted to, but what does that really well down to? Is it simply that about eight hours a day of practice for a dedicated period of time is what leads to rapid plasticity and that's what was measured? Or is there really some sort of rule about time under seeking clutch state? The simple answer is what the study showed was that 10,000 hours was the average amount of time that an expert violinist had spent practicing by the time they reached 20 years old. That's what the study showed. They weren't even experts by that point. That was how much they'd practiced essentially in their youth. So that number of hours doesn't even translate over to true expertise in violinists in this one specific example. So I don't think there's some fixed number of hours required. It is interesting other parts of that study kind of looked at the practice routines of these expert violinists. And what they found was that they tended to practice for about two sessions of 60 to 90 minutes a day. And I think that's a pretty good rule. If you're going to do something hard, you're pushing beyond your current skill level, focusing for 60 to 90 minutes maybe with a couple of breaks in there, a couple of times a day, that's probably about as much as most people can do. And I think that also relates to how we perform on a day-to-day basis in other areas of life. We kind of expect that we can go to work and we can work really hard for eight hours straight during the day. But like the brain doesn't really work like that. If we're doing hard, cognitive work, you're focused and highly challenged as you might be if you're a future virtuoso on the violin, you're trying to really practice and push yourself. You can only really do that for chunks of 20 to 30 minutes, maybe a couple of times of the break. So that's why Pomodoro, even though there's no good studies on the Pomodoro technique, like for those time periods, 25 minutes or the five minute break a few times, they do kind of fit into that kind of rhythm. That translates over to multiple areas where we might want to use our brains. And just remember that hard, cognitive work and that process of learning can only really happen in those kinds of chunks if you want to do them sustainably. Yeah, before I started writing my book, somebody who's published several very well-received books said you can only write for about four solid hours per day, broken up into a couple of sessions. Yeah. I was like, "Come on." I mean, I'm not trying to post, but I used to go into the lab and sit down and work on a grant for six hours or something like that. And I started thinking, like, "Was it really six hours? Go in there, see my students and postdocs, sit down." Okay, then there was lunch and you know, "Oh, my dog." Yeah. And there were some late nights, but then the next morning I'm kind of dragging because I was in, you know, in my office really late and you get real honest with yourself real quick and you go, "Oh, okay." In the periods of time where I definitely pushed to the six, eight, ten, twelve hours of just non-stop work as a deadline approached, there was a compensatory drop in output after you click send. And so I think you're right. They're right. It's somewhere between maybe, I mean, you're saying 60 to 90 minutes and they're saying four hours, but not a whole lot more than that for real focused in clutch state work. Yeah. So really digging in and no distractions, no phone, no checking your text messages, just, you know, do you ever give yourself forced constraints to get real work done? Not to force it. I will say that one of the best ways to like truly get deep focused work done is to eliminate distractions, right? That's one of the most important things that you can do. So close the email. I'll like put my phone in a different room or stuff because like nowadays your own, you know, close slack, I have slack teams, my lab and I, we interact on, you know, we mess it back and forth on WhatsApp, like there's email, I've got like five or six different ways that people can like constantly try and get my attention, right? So like, eliminating distractions is really important. And again, I've returned to Gloria Marks, we're actually writing an excellent book called Attention Span, if anybody's like really interested in this. But you get used to a pattern of distraction such that when you're not actually being distracted, you will distract yourself. Right. But you can be trained out of that as well. But so you know that thing where you're trying to do work and you like reach for your phone for no reason, it's because your brain is kind of used to this pattern of that around about now, somebody would text me or send me an email and I'll reach my phone. So you go looking for it, even if it hasn't happened. But again, you can train yourself out of that. If you have periods where you're not getting constantly distracted. So I will eliminate notifications. But at least for me, what I found is that if I have a ton of friction in terms of trying to get something done, I will usually step away from it because there's something in there that just like needs to click or come back before I can like really engage in it. Or if you're at a sticking point. Yeah. So if I'm at a sticking point, it's like if something feels like it's just not coming in the moment, I'll usually switch over to something else, which is also kind of a normal, it's one of a possible set of patterns of work, which is that you have two or three projects you're working on on any given time. If one just like isn't quite working, then you can switch over to the one and come back to it. And then like the alternative is that when the deadline is so close and this often happens with a grant deadline or you know, when I was writing my book and there's a book, you know, a book deadline and you've got to get this to my editor in how many days or hours, I tend to just not need to to eliminate those things because I'll just focus in. Like I don't feel that kind of draw to be distracted by other things. But that usually happens for relatively short periods of time, right? It's going to be a day or two or hours during a day rather than you know extended periods of time. Are you familiar with this recent study about phone on the table, phone on the bag? We would just remind people that if your phone has to be out of the room, even if it's in your bag, beneath your chair turned off, you can still focus, but there's a cost, your cognitive flexibility, etc., really suffer. So that means that the brain is unconsciously expecting a call, instead of waiting for it. And the way you describe this attentional break expectation thing that we get entrained to interruptions is really interesting. Maybe this is why meditation is such a useful tool for improving focus is that it's just a forced no breaks thing. Although it's pretty easy to drift in meditation. If you are not used to doing 20 minutes of meditation, you sit down to do that. You set the timer like your brain can end up way off the trail. There could be some benefit to that as well, right? Because there's you know, without kind of building that in and I don't routinely meditate, but unless you have some parts of your day, where actually you're not either putting in information, distracting yourself, thinking about a specific thing, right? You don't necessarily get that time to integrate. That's kind of, you know, the classic is you can't with your best ideas in the shower, right? Because it's actually the time when you don't have your phone on you and you're not watching TV and you're not doing all these other things, you know, at the same time. So maybe yes, that's not what meditation is formally for, but it could potentially be beneficial. If your mind's gonna wonder, making new connections, coming up with new ideas, having that space and time to do it, it could potentially be beneficial to you. - In these studies, these large scale trials, what was the diet intervention? Can we distill it down to some things that everyone should do or ought to consider? - Most interventions in the sort of cognitive and psychological space are focused on some version of the Mediterranean diet. There's the mind diet, Mediterranean intervention to prevent neurodegenerative delay came out of the rush memory and aging project. And it's basically just a version of the Mediterranean diet kind of focused on dementia prevention. And the way they initially created it was they looked at foods that people ate more or less of and created a score and those who had a higher score tends to had a lower risk of later to mention. It wasn't an intervention when it was first developed, but that was kind of diversion. It was kind of combination of the Mediterranean diet and the dash diet, which is like a anti-hypertension, blood pressure treatment type diet. So it's seafood, vegetables, berries, whole grains, that kind of stuff. Not too much saturated fat or animal protein. - Yeah, and so this is very similar to the diet they use in the Smiles trial, which was the first randomized control trial in depression that showed significant improvements in mood symptoms. I think the principles are useful, but there's not necessarily a huge amount of evidence to say that this is the way that you should or you have to eat to maintain cognitive health. There was actually a big trial of the mind diet that was called the New England Journal of medicine a couple of years ago. And they compared the mind diet to standard chloric restriction. And actually, they saw similar benefits in both groups. There have been big observational studies that have looked at how much their diet looks like a Mediterranean diet. And those whose diets look more like Mediterranean diets, yes, they have a lower risk of dementia. Of course, right, this is observational data, right? So it's not, you can't say it's causal. But what's interesting in some of these studies, that was a big one that came out of the UK Biobank was that they took out individual foods or food components of the Mediterranean diet to see if that changed the relationship between the Mediterranean diet and dementia risk. And there was no food or olive oil or food group or you're eating more or less meat that changed the relationship between the Mediterranean diet and dementia risk. So what that tells me is it's much more about whole foods, their nutrient dense rather than avoiding any, you have to consume lots of olive oil, right? Or you have to restrict meat. Because if those things are eaten in the context of all this other stuff, it's really that bigger context of diet quality and nutrient density that really matters. So the parts of diet that I think about are the, there's three. So there's energy, there's nutrients, and then there's overall dietary pattern. So one of the confounding things about that trial, I told you about the mind diavursus caloric restriction is you're like, well, the mind diet should win out, right? How does caloric restriction do just as well? And in the kind of average population, we tend to have some issues with metabolic health and have been in a state of chronic energy excess for some period of time. There's been some very nice studies that have looked at brain aging and brain volume or brain reserve across different populations. There was one group that looked at different tribes in Bolivia, the Bolivian Chamane, who are one together a group, the Mousetan, who are kind of an intermediate group between the Chamane and like a standard kind of industrialized group and then industrialized humans in the US and Europe. And what they found is this kind of this bell shaped curve between energy availability and brain volume and in general, brain volume, right, the more the better, right, we think. And so if you're chronically, caloricly restricted, your brain is smaller, 'cause you just don't have the resources to invest in the structure and to maintain it. At the other end, you see the same thing. So if you're chronically in a chronic state of caloric excess, you also tend to have a smaller brain on average and this is related to metabolic disease, and potentially, what comes with it, higher levels of inflammation, high blood pressure, things like that, that we know can negatively impact the brain. So the most important thing, and I think this is where some of the benefits of chloric restriction happened in that trial compared to the mind diet, was that people's cognition improved just because they decreased their energy and take to a point that was more, was essentially kind of what their brain kind of needed, or kind of supported their overall physical health, which then affects cognitive health and brain volume and brain function. So the first thing to do is to make sure that you're eating enough, but not too much. And that's very simplistic, but energy is really critical. Energy availability, not too low, not too high. Then the next thing that you need is nutrients. We know there are several critical nutrients related to cognitive function and risk of dementia. The ones that we have the best evidence for vitamin D, iron, omega-3 fatty acids, the B vitamins involved, and the B vitamins involved in methylation, so particularly B12 and folate, also potentially B6 and riboflavin, although that might depend a little bit more on the individual. Then there are some other nutrients that have some pretty good evidence for them, so many of the anti-oxid polyphenols, things that you get from berries, coffee, tea, chocolate, the crotonoids that make things orange, yellow, and red. Lutins, eosanthin, astasanthin, if it comes from seafood, that's what makes shrimp and salmon pink. And then some other aspects like dietary fiber seems to have some benefits as well. Not magnesium. So magnesium is absolutely in there too. And in general, I think, and magnesium, zinc, then there's some of the structural lipid components, things like co-lean and ethonolamine that you might get from nuts and seeds or eggs. They have some slightly less evidence. You're really when you're looking at brain changes of a time and dementia risk, but those certainly do seem too related to cognitive functions. So there are some studies that show that those who have lower magnesium and takes tend on average to perform less well on some cognitive function tests. So all of those do seem to be important. I have two questions about nutrients and brain health in short and long term. And they have to do with interactions between nutrients, which, at least to my understanding, are rarely explored. You'll see studies of supplementing omega-3 or having people eat some fatty fish or less and so on. But rarely in the presence or absence of some other vitamin that can potentially impact the same pathways. So there's synergy. There's also necessity. So that could impact results. The other piece is on what time scale are these nutrients needed and on what time scale are they metabolized? So maybe to just kind of drill into the second question first. So I'm not out here as like the defender of supplements. But I've been taking supplements in various forms and eating whole foods and eating it generally healthfully, less so when I was younger, but still pretty healthy and more so as I get older. But here's where my brain goes, wait, whole food is great. But let's say dark leafy greens have a bunch of things in them that are fundamentally important for brain and bodily health. Great. And they have fiber, et cetera. How many times a week am I eating dark leafy greens? Let's say I do Monday, Tuesday, Wednesday, I'm great. But then I'm traveling on Thursday, Friday. Should I be just supplementing Thursday, Friday? Am I good until the next week? I think one of the reasons why eating really well, I think everyone knows what that means. Enough calories, not too many, mostly whole foods, et cetera. Enough vegetables, fruits, and high quality protein and quality fats. I think the reason why supplements still become enticing to me, maybe even necessary is because you can take them every day very easily so you can make sure that you're in range and maybe above range. So let's take one of these things. Okay, Omega-3 fatty acids. I believe that the data are pretty compelling. They can be helpful for health, maybe even brain health. Certainly, I believe that. But let's say the early part of my week is Omega-3 rich and the later part of my week is Omega-3 poor. Am I good? Versus spreading it out across the week, it just becomes difficult to eat in a truly healthy way if it's the case that it has to be consistent every 24 hours. So what do we know? So again, I think we're often tempted to overcomplicate this and try and think, "Oh, I have to hit all these things at this interval "and if I can't do that, then I have to supplement." And in reality, we probably have more buffer in the system than we realize. So Omega-3 fats is a really good example. Your adipose tissue, your fat tissue, is a depot. You know, it kind of stores excess Omega-3s. Actually, I wrote a paper on this with a colleague of mine, Rory Heath a few years ago. The long-term. of mega threes that we have in our fat stores, may help to explain why supplementation does or doesn't work in some of these trials because some people just have more kind of hanging around. And if you eat more than you need on one day, especially in a state of caloric excess, that's going to be stored in your fat tissue. And then when you're sleeping or when you initiate like policies, the breakdown of fat, so particularly during periods, like you're doing exercise, those then get released and the other brain then has access to them. So there's some studies that show that when you, this relates to the form of the mega threes as well. So many people will tell you that you have to take a mega threes in the phospholipid form, which is like a special supplement. You can get it from krill. And the form is the fat is attached to like a phospholipid head group, just like it would be if it was sitting in a cell membrane. And there's a specific pathway for those to get into the brain. It's only kriller is for sure. No, so fish tends to be the triglyceride form, which is your glycerol and then three fatty acids attached. When you compare a single dose of phospholipid versus triglyceride form, then more of the phospholipid form gets into the brain. Some of this, you have mostly comes from rodent studies. But what's interesting is if you supplement over several days, it all kind of comes out in the wash because the triglyceride form cycles through the adipose tissue as a depot and then it gets released and the brain can then use it. So if you're going to take just one day of supplement and you want to get as much of that mega threes in your brain, yes, you should take the, we think we should, you should take the phospholipid form. But the form that comes in seafood, which is primarily the triglyceride form, is regulated through the body's fat stores. So this is a really long way of me telling you, if you eat some fish early in the week, you don't then have to supplement later in the week, as long as you've got, you kind of enough. And especially if you've consistently eaten seafood across your entire life because you probably have a bit of a depot. And so what you see in several trials where they've given a mega threes to decrease dementia risk or improve cognitive function, so many studies of like that have been done. There was actually a very recent one that just came out of USC where they gave mega threes for a long period of time. They measured a mega three levels in the, in the CSF right in the spinal fluid. These people to show that this, the mega threes were getting into the brain. They didn't see any changes in terms of cognitive function or brain structure or an MRI scan. So everybody's like, well, a mega threes don't work. But when you kind of squint at the data and they didn't quite give me the data that I wanted. But when you look at it, those, the people in the trial just didn't seem that a mega three deficient in the first place. So right, if this isn't something that you need more of to start with, giving a load more of it isn't going to make that much of a difference. Right. And this is the case for all of these different supplements. So the best advice if you have access to it is to test your levels, test your vitamin D levels, test your hemoglobin and iron levels, test your mega three levels, test your home assisting levels, which is as a marker of a B vitamin stasis, which we know is a risk factor for cognitive decline dementia as well. So if you can test your levels and it shows that you need more and yes, there are the normal ranges that you have on a blood test are not necessarily the same as the risk ranges. So home assisting is a good example. A normal range for home assisting, which goes up if you need some of these methylation dependent B vitamins, the normal range might go up to like 15 or 16. But we know that risk is definitely elevated above 13 and is probably elevated above sort of 10 to 11. So what your target range really might be is probably lower than what the normal range might be. But we have very good evidence that if you then supplement when somebody is above that range and you bring that down, you see significant improvements in in cognitive function or slowed cognitive decline. That is particularly the case for a mega three's and B vitamins that lower home assisting. And so this is the interactions that you're talking about earlier. And this is the best one that we know of, although I'm sure there are many more. Like I said, there are lots of trials that have given omega three's or have given B vitamins to lower home assisting and just haven't seen much of an effect. And everybody is all whether they don't work. But there are now at least three randomized control trials that have shown that omega three status and B vitamin status interact and then dependent on one another. So if you give B vitamins to somebody who has elevated home assisting, you bring down their home assisting, but they have poor omega three levels. You don't see any benefit. And so that's been shown in two trials. It was originally shown in the Vysocog trial that was run out of the University of Oxford. It was then replicated in the B proof trial. Then the other side has also been shown there was a in the omega AD trial. They showed that a supplement to with the mega threes didn't result in any benefit if people had elevated home assisting. So that's just one example. And you could imagine, like you kind of said, there were probably lots of these. And if we're not, you know, going into a study, actually looking like, well, what nutrients does this person need and then supplementing with them, you're not going to find any effect. You shouldn't be surprised when there's a when the study doesn't show anything. Potentially the one recent example of kind of just giving a broad based kind of set of nutrients or with the multivitamin that seemed to work fairly well was the cosmos study. People may have heard of it was thousands of people of older adults. And they were given either a multivitamin or a flavonoid supplement. It's like a centrum type vitamin. Yeah, it was centrum silver. Like the most basic multivitamin, just 100% of the recommended daily allowance, not like no multi, no like massive doses of anything. And in that study, those who got the mill, got the multivitamin saw, you know, changes in cognitive function that suggested some, like some, some improvements. And that was literally just covering the basis, right? No massive doses, the most basic multivitamin. So in the kind of general population, I think you could say that something like that is probably a reasonable strategy. But what they also showed was that supplementing with this antioxidant cocoa flavonoil was only beneficial in those who tend to have a poor quality diet to start with, right? So they just weren't getting many of these kind of compounds for their diet. 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Again, that's functionhealth.com/huberman. Thank you for that clarification. I look forward to a day, hopefully not long from now, where people get their blood work done. They are told and they decide, it's a collaboration after all, which supplements to take? Ideally, those supplements are tailored to them. So it's not gazillion tablets and capsules, and then they can redo their blood work and see whether or not things come into range. And of course, that should be measured against subjective experience of well-being and sleep and all of that. That's not hard to do in today's environment of technology and trackers and blood testing. It's just that we're a little bit in the, still in the 90s, even just the way that most people talk about supplements, certainly not you. But I think when people hear supplements and they go, "Oh, it's expensive. You're in, okay, that's vitamin minerals. Maybe some of that is just getting a urinated out." But then there's food replacement supplementation. And then there's supplements to get a specific desire to affect. Speed up the transition time to sleep. Get more slow wave sleep, more focus, etc. So it's unfortunate that we don't have good nomenclature like we do in science, where words are very important so that people can communicate with accuracy. And I also wonder whether, okay, if one gram of omega-3 EPA per day is good, but maybe three is better, even though I'm a, you know, upper range, upper reference range. And this is something that like nobody really wants to address because then it sounds like, quote unquote, "biohacking." But ultimately, I think people want to feel good. They want to live longer. No one wants to do anything dangerous. I feel like we're really in like, in like, prehistoric times with how we think, how most people think about nutrition and supplementation. I feel like the last 40 years have been spent mostly focusing on what's bad for us. I'll get trans fats, bad, fried foods, bad, eating too much bad, right? Energy over, energy toxicity, bad. Too much alcohol, bad. Zero is better than any, but you could probably drink a little bit and be fine. Okay, if you're gonna take nicotine, don't smoke it or vapor, like we sort of figured it out. Right, don't hit your head. If you do, don't hit it twice. You know, like we've sort of been spending so much time on the don'ts, then now I feel like we're in this exciting time of what can you do for one's health and then there's this divide, right? Just see all foods, you'll be fine and you've actually convinced me that we'll be fine. The question is, could I be that much better? This is really interesting to me because there's two different parts to it, potentially. Although they may end up being the same thing. So one is, if we're thinking about, if we're thinking broadly about improving brain health, cognition, and the population level, what's really important is kind of raising the floor. Like what is gonna work for everybody and get most of us most of the way there? So like that really is improving food quality and then access to those foods as well, right? Because that can be very inequitable. Like can people afford it? Do they know how to cook it? Can they access it? And then within that, I think we also know we have very good evidence for cutoffs that predict risk. And if you can't get those nutrients from food, I think we should supplement. I think I like to call nutrients like the great leveler of like there's no point in arguing about different diets because your body requires these nutrients and like I don't care where you get them from as long as you get them, right? So if you need to get them from supplements, I think that's fine, that should be fine. When you then get kind of to the next level, like how much further can we push function? My answer is I genuinely don't know. Like when you say like, if I test my omega three index, right? You said it was the kind of the higher level. Maybe it's seven or eight or something like that. All right, if you push it to 12, is that better? A genuinely, genuinely don't know. Like some of these more complex AI systems data collection kind of seeing how you then respond individually. As long as you can perform your own sort of like personal experiments, right? As much as you can hold one variable constant, have some meaningful output that you can kind of track over time, see whether it works or not. Can we then aggregate those data to kind of better understand this? I'm excited to see where that goes. I will say that the best evidence we have just says, in reality, don't be deficient. If you can reach that threshold of not being deficient or insufficient, maybe that's enough. I'm hopeful that that's the case, right? Because then more people will get to that point more easily. But there's a lot that we have to learn there. There was a time in the 90s and 2000s, where people would take stuff and do stuff. I'm not talking about animal steroids, although that was happening too. And the whole idea was find things that work perform really well in one's job or in one sport. Assuming you're not breaking any rules, right? But not tell anyone you were doing it. And what changed, I think, were two things. One is there became a market value for telling people what one does in order to make money. So people started doing that. And I do believe sharing is good, right? But also, there's this problem that goes with that is that people who sit on the outside of brain and sports performance or just life, just trying to maintain memory and do well in school and be a busy person and still get sleep and all of that, feel like, oh, you know, we're being sold this one thing that's supposed to make all the difference. And I think the thing that really came in and changed all of it are the GLPs. I've never taken a GLP, but I'm just struck by like, Americans are now willing to inject themselves. So now it opens up this whole thing about peptides, which, you know, the major consumers of peptides are not the broscience guys, like the Jim bros. It's women who, look, I have female family members, right? Who have, and they'll tell me, and there's a long history of people doing and taking things and doing things for their cosmetic appearance. And not necessarily sharing it with the world. So these are the performance enhancing substances of a whole different kind, right? And so how is it that this peptide industry is so intriguing, so many people that, yeah, like jabbing yourself with something that is not FDA or proof, like people are doing it like crazy, even people who are kind of cautious about what they'll do and put into their body because of this bridge that the GLPs have made. It's so much easier now to just, people aren't as needle phobic. So I think we're entering a time now where people are saying, okay, you know what, the government, the food pyramid, whatever, the food quadrant's like, yeah, that's just like if you don't want to die, but I want to feel great. And there's actually this potential that you and others are sort of offering, like you can learn things into your older age. You can be a lean and have great posture into your 60, 70s, 80s, 90s, we see examples of this. So I think that there's this pull, we're getting kind of pulled forward towards this promise. And I don't think that promise is all about avoiding the bad stuff. And people will say, oh yeah, well, my grandfather lived to be 102 and he was smoking every, great, like awesome, but a lot of people don't have those kinds of genetics in their family. They really, and genetics play a big role. So I'm kind of editorializing here. I'd love your thoughts on how you sort of sit back and you look at the landscape of things. Eat right, exercise, get good sleep, socialize is awesome. But that is just that is difficult for people. That puts people into a clutch state, just trying to do that while managing family and profession and cost of life, cost of living. That's a lot. So I think people do want something that gives them more energy, gives them better sleep. Picks up their mood, and I don't think there's anything wrong with thinking about those things as long as it feeds back to better behaviors. Particularly when I think about this new part of the supplement industry. And like you said, the peptides are just the next, they're the next iteration of the pills and potions and things that people have. They're willing to supplements more than drugs because look, there's no putting the genie back in the bottle. I don't care what the FDA does and they can mark my words. People are going to find their way to get their peptides because they love them. And most people are not playing a drug tested sport. And there may be adverse events out there and this isn't a plug for peptides per se. But where are all these adverse events that are not from botched injections or from really bad black market sources? Where are all the roydrages of peptides? Where are all the, like, I think you can see way more plastic surgery, like, whoa, that looks bad. Kind of things in it, like, okay, melanotans kind of an issue because people can really mess themselves up there. But where are all the adverse events? Until people start dropping dead from BPC injections, people are going to get and they're going to take their BPC. - I'll admit I'm more conservative. When you're trying a new supplement or a peptide, I'm going to include peptides into this. But of course, you could be a pill or whatever, right? Some peptides come as pills. I would want some reasonably good evidence of efficacy. So this is going to work in humans like me. That's probably not a bar but most of these things are going to hit anytime soon. - No, people don't care. I mean, people who have no interest in walking into a gym are contacting me like crazy. These are adults who have kids they love, spouses they love. They are not medicine phobic, like traditional medicine phobic. And they're like, should I be taking logos? Should I be micro dosing to his appetite or read a true title? Like, read a true title is not even released yet. They're like, where can I get it? Like, are you kidding me? You know, but it's incredible what's happened in the last few years. - So think about what you might think about if you're gonna start to consider one of these. First of all, I would want to see evidence that it works. The majority of peptides don't have good quality evidence in humans except the GLP ones who are either on the market. - And the growth hormone secretedogs but for reasons other than people are taking. - Yeah, yeah. - Soccophenia, you know, other, and with the, most of those growth hormone secretedogs come with a risk of insulin resistance. Diabetes are high, particularly at higher doses. - Yeah, they're not the super popular ones. I think the super popular ones are besides the GLP's and the red and true tide is a GLP and other things. But I would say micro dosing of red and true tide enters appetite, one category for weight loss, fat loss. I would say BPC157, people are taking it without even knowing what the desired effect is. Recovery is a really broad. I think it's injury repair, that's the thesis, no human evidence as far as no good human evidence. And then there are these other kind of dot, dot, dot ones I would say GHK copper or skin appearance. Those are the three biggies that seem and the last one in particular with women. - So I would want evidence that in humans it does what I wanted to do. Most of those, if not all of them, except for the GLP ones don't have that evidence. All for the thing that you're trying to get, right? But beyond that, a question that you have to ask, and I like this reframing, I heard it recently from Jeffrey Blande, which is that if you're going to consider injecting or taking something, the first thing you should want to know is this safe, right? If you have good safety data, then trying it is low risk, right? Even if it doesn't work, right? At least you know it's not dangerous. But we don't even have that for most of these. We just have the absence of documented adverse effects. Yeah. And in the time course that they've been used, because we don't know about long term use. And so everybody has their own risk tolerance. Everybody is welcome to do whatever they want, of course. But for me personally, first, I would want documented evidence of safety. And then you can say, well, I'm willing to try it because, you know, may or may not do this thing. But you should also have a specific problem that you're trying to solve, right? Otherwise, why would you be able to taking it? But it's also the case for the vast majority of supplements that are out there and have been around for a long period of time is, first of all, we don't have good evidence of long-term safety at whatever dose that you're taking. And then second of all, we don't know whether it works. First of all, we do like creatine, and then we have mega-3s, magnesium. And creatine is actually the best. So like a mega-3s, we know that they're a critical nutrient. Creatine, I think, is the best example because we know it's very safe, right? But even though this idea of creatine responders and non-responders, maybe it's going to be useful to improve or support cognition for some people or not others, may improve physical performance for some people or not others, at least we know that you can give high doses of creatine to frail older individuals with essentially no side effects, right? We know it's very safe. So then you can try it and see if it benefits you. So creatine is a great example. But there aren't that many others that kind of fit into that category. So it's interesting times. Again, I go back to it. I love the idea of blood testing, tailoring supplementation to the needs of the individual retesting so people can be really objective about whether their levels are moving in the right or wrong direction, subjective experience. The sleep supplementation thing is kind of interesting because either people feel it improves their sleep, or it doesn't. Even if it's a placebo effect, which in some cases it could be, with sleep tracking people can see are they getting more REM, or are they getting more slow wave sleep? Such a fascinating area. I mean, as you and I both know, there's no plasticity pill, but arousal alertness, focus seems to be a prerequisite of plasticity, which is why things like caffeine and stimulants and altiracine and all these things that you can find some evidence for them improving plasticity. But it's very likely to be indirect, right? It's not that they make you learn. They set the stage for learning. It seems to always get back to arousal. So this is what I want to get back to exercise as a tool for opening the window for plasticity. Could it be that it's simply a matter of moving your body to get enough adrenaline in your body, nor up and effort in the brain, and maybe some dopamine as well, so that the stage is set for plasticity. And it doesn't matter whether you jump rope, do jumping jacks, sprint, or do deadlifts. It's all about getting your brain into an altered admittedly endogenous chemical altered state of just more arousal. And then boom, you can go learn. Is it, I mean, could it just be that before we get into the exercise, there's an interesting part with the supplements that increase arousal, right? So the stimulants in particular. And I am a big proponent of thinking about or tracking how somebody feels, right? I think that how you feel is this kind of ultimate integration of all these inputs and outputs that the brain is kind of bringing together, right? And we know that how you feel, so how an athlete feels is a much better predictor of their performance than their HRV or any of their blood tests. What do you ask them? Like, how good do you feel today? Yeah. I'm one to 10. Some, some version. I feel like I can conquer the world one. I feel like. Exactly. And you can boil it down or, I mean, you can spread it out to many more questions. There's a question there called the rest Q, which is all about like how you recovered, how recovered you feel, how motivated you feel to train or perform that kind of stuff. But essentially it boils down to how good you feel. If you feel good, you're more light and perform well. And that works better than the vast majority of data that you, you know, biological, physiological data, you can collect. There are papers that come out this every year that essentially show the same thing. It's kind of cool. Yeah. Because mindset, as my colleague Ali Krum has focused on so much, like mindset can be, you can be honest with yourself and you can lie to yourself and tell yourself, like, okay, you got a lousy sleep score, but like, I feel good. Yeah. Or, you know, maybe sleep scores are like, they mean something, but today, you know, right? I mean, it can work, right? I mean, in terms of performance. Yeah. And so absolutely right. Then that gets into like the no-cebo effect of how we think about either our sleep data or these other things, right? That can negatively impact our performance and we have good, good studies that show that as well. So, I think that like tracking how you feel is really important. But when it comes to stimulants in particular, they seem to dissociate how we feel versus how we perform, right? So there are studies that show that giving people caffeine makes them feel like they're performing better, but they're actually performing worse on certain cognitive tasks. So there's been studies done with like the the end back tasks. So like, very complex, you know, working memory tasks, particularly as you get like to like N3, you're like trying to remember, did I see this letter? Three letters ago, right? In those kinds of complex cognitive tasks, people who take caffeine feel like they're performing better, but they're actually performing worse. They're making more errors or they're kind of, you know, they're reacting too quickly. They're not really thinking about it. And there is the similar data from other stimulants too. There was a paper that came out in science a couple of years ago, giving people their methylphenidate, some of the other like ADHD medications in people who don't have ADHD. These stimulant medications again show this dissociation between, so they feel great. Let's take the the inverse of the cannabis thing where people think they got all these great ideas. And then the next day even they are like, oh my goodness, this is dreadful. Yeah. And that's again been like formalized in studies where you can do these tests where then other people objectively see how creative were you, people taking cannabis felt like they were more creative, but actually they weren't. And so the reason why I say this is that when we're talking about supplements, all these other things were like, well, I feel much better. Therefore, it must be, must be doing something good. We know that with many of these supplements, you can create this dissociation between how you, how you feel and how you perform. Whereas some of these endogenous things don't have that effect. So that's why that kind of like endogenous increase in arousal using things like exercise is a much more reliable way to improve performance because you don't kind of get this dissociation between the two. So with exercise in particular, we know very well that some period of exercise can be resistant training, aerobic exercise, very brief sprints, increase arousal, improve cognitive function across multiple domains, improve learning and retrieval. So you're definitely augmenting some of these process neuroplacicity. Some of that can be related to the cataclysmines and other things that get released as you, as arousal increases. But we also know that different types of exercise have different effects on different parts of the brain. So yes, I think some of just like the general process of moving your body and exerting effort definitely increases arousal definitely improves cognitive function, improves learning as long as it's not truly exhaustive exercise. Like anybody who's done some terrible crossfit what or we are used to be a row, we used to a 2k test on the row machine, right? You do a 2k test on the row machine, your brain does not work afterwards. It's like a six minute flat out like VO2 max kind of level of exertion. Yeah, thanks. I'm going to interrupt briefly. I'm just pointing that out because I think that people assume they have an infinite amount of energy and there's crossover and I certainly have done extra sets to failure in a great morning workout and then in the afternoon I'm dragging. If I hold back just a little bit in terms of volume, I find I get a real boost out of training. I do low volume high intensity, usually two sets per exercise, two or three exercise per muscle like quadriceps being one muscle or something like that. If I do three, there's a small addition, right? The rest of the day I'm kind of dragging. So leaving something in the tank does seem worthwhile, not during the sets but leaving something in the tank in terms of volume really seems to help. Especially if you want your like to perform hard cognitive work directly afterwards. Sometimes if you're trying to really push performance or adaptation, right, it's worth digging into that hole but it really just depends on what you want to be able to do directly afterwards. I think student athletes, especially in D1 schools, they really come to appreciate this. I've had a few of them in my courses over the years and they really understand when they're pushing very, very, being pushed very hard in their sport and they know that they have to sit in the front of the classroom, sit upright, take extra measures to make sure they're not dosing off, attention drifting, especially in the age of phones and iPads and things like that. very, very difficult. Yeah, thank you for mentioning that because they're just an extreme case of the rest of us. You know, we're told we're all very busy. Like, oh, you need to exercise. It'll help your brain and be like, well, I exercise and I'm exhausted. You know, that's not helping my brain. Let's get practical here. So is there any way to, it's got to be really subjective and depend day to day? Is there any way to kind of formalize that? Like, should you train, let's say, resistance training or running, you know, should you cap it at an hour? Should you pull back on the intensity if you have harder cognitive work to do in the afternoon? We all want the maximum effective exercise, but we don't want it to undercut our efforts. Yeah, I think that a lot of it's going to be based on what your current capacity is, right? As with everything. So if you're, you want to do some, you got some, you know, learning to do, you got an exam, you want to do some hard cognitive work at, you know, whatever it is, writing a presentation, analyzing data, really, really papers, writing a book, then doing some kind of workout that's probably below your kind of typical or below what you would do when you're really sort of pushing, pushing the envelope. I think that when you look at meta-analyses of exercise and then cognitive function immediately afterwards, the protocol that has like the best evidence for it is like a 20 to 30 minute jog, right? So like, that's the kind of level of activity that the, the really seems sort of like support all those general processes of plasticity and learning. What do you think is going on? Because it can't be that much arousal. I mean, the amount of cataclysmines released from, again, cataclysmines, folks being the, you know, adrenaline, norepinephrine and dopamine, generally increased levels of arousal, alertness, propensity to move. You just, that's that. I feel better. People often think about the runners high and dorphins. The dorphins come from pretty long intense duration effort. They're more of a, you're floating kind of like, you know, I think the cataclysmines are really the cocktail of like, all right, I got a great workout in this morning, showered, got dressed, I'm off to work. Let's go. That's the, so 20 to 30 minute jog. I don't expect to get that much cataclysmine release. I mean, you'll definitely get some, right? And like, quarter to two, right? Which obviously increases alertness, and arousal, and can in the short term, make you feel good. It's a good thing. You see similar effects of, you know, short resistance training workouts. I think of it. It's probably a little bit of like an area under the curve thing, because you see some similar effects of like, you go out and you do six second really hard sprints, like max effort sprints, you do that a few times with a long break in between, right? That seems to have a similar effect, but you're only working for very short periods with very long rest periods. So it's something in that, in that sphere. And I think it's, that's probably just it. It's just enough to, you know, just kind of boost cataclysmines a little bit, a little bit of quarter-zol. That's enough to kind of move you up the arousal curve to the point where you're then able to focus and engage a little bit better. I think, yeah, you don't need a huge dump of that in order to achieve that increase in arousal, particularly as it pertains to like learning and then, you know, cognitive performance in like formal cognitive tests, which is where this is usually done. If you're then thinking about the type of exercise that changes cognitive function or brain structure long term, effort and intensity do seem to matter a lot more, but those studies have looked less at what I had, how did that, how do they feel directly afterwards, right? Now you're thinking about what's the kind of stimulus that drives change over time and then intensity matters a lot as well. So the best example is with aerobic exercise on the kind of zone two, up to kind of zone four, five sprint spectrum. So most people who listen to your show are probably familiar with a study where in older adults, they had them do a brisk walking three times a week, 40 minutes. And when you kind of read the study and the heart rate levels, they were trying to attain it was basically zone two work, 40 minutes, brisk walking three times a week for a year. And they saw significant increases in the volume of the hippocampus, increases in VO2 max, fitness, increases in circulating BDNF levels, though circulating BDNF doesn't actually get into the brain, but it's kind of telling you something about Crowley BDNF that's being produced in the brain and improvements in memory with all of that. However, there's a much more recent study that took again older adults and randomised them across three different groups. Another group basically did kind of zone two type work on a treadmill three times a week, very similar to that previous study that I mentioned. And the third group did a high intensity interval training intervention, which is the Norwegian four by four protocol. So four minutes, 85 to 95% of maximum heart rate, they had a three minute rest in their protocol, they did that four times over. That's really hard. Anybody who's done the Norwegian four by four, if I you then say, well, hey, do that three times a week for six months, like that's that's three times a week, three times a week for six months. That's that's pretty intense. But what they showed was that that high intensity interval training group, they improved their fitness just as well as the zone two group, interestingly, but they had much better improvements in hippocampal function and maintenance of hippocampal structural and MRI scan. So they worked really hard for six months, but that that benefit was maintained for for a really long period of time. And in several analyses within that study, they basically show that the harder people worked and the more courses all they released, the better the benefit. And so this is important because nowadays there's, or you know, there's several people out there saying, well, don't do high intense exercise. It releases cortisol, that stress for your body can't handle it, right? This study directly shows that working really hard, releasing a lot of cortisol in high intensity interval training actually improves hippocampal structure and function over time. So yes, I imagine after they did their workouts, their brain wasn't maybe working at its best because that's a hard workout. But over time, this is this really strong stimulus that then resulted in significant improvements. Forgive me if you said it and I missed it. What was the form of exercise? Was it rowing or biking or running treadmill? Yeah. Really interesting. And you said it about 85% of max heart rate. Yeah. So that's that's a typical Norwegian 4x4 protocol. But I don't think that's the protocol you have to do. I think it's just this process of high intensity exercise that it releases a whole bunch of myakines and lactate in particular. We know that lactate very easily gets into the brain, generate, you know, stimulate speed in F production as kind of part of that support of neuroplacicity or augmenting recent neuroplastic processes. I think there's something about that, just that high intensity work that drives some of those factors that then support structure and function. It's an unfortunate reality, but tap water often contains contaminants that negatively impact our health. In fact, a 2020 study by the Environmental Working Group estimated that more than 200 million Americans are exposed to PFAS chemicals, also known as forever chemicals through drinking of tap water. 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Again, that's roora. R-O-R-R-A.com/huberman. Two things, a super interesting comparison between these studies. As somebody who incorporates one day a week of four by four type exercise in one day of longer, slower cardio, maybe I should try maybe doing a bit more of the high intensity. I think if you wanted to be sustainable for long periods of time, I would typically say one day of high intensity work is fine. You probably want to be doing some resistance training. I'm doing that three days a week. I do one long slow for me jog of about 60 minutes, 45 to 60 minutes, and then one moderate, maybe more like zone three, four. Thank you for putting in a strong word for cortisol not always being the bad guy. People are so afraid of cortisol. You want your morning cortisol high? It's going to make you sleep better at night. You have more energy during the day. It's interesting to me to dive into literature on cortisol and find that a moderate intensity resistance training session or cardio session, probably a little bit easier than the four by four, will triple one's baseline levels of cortisol. We're quadruple it. It's transient, but nobody's freaking out about these workouts, but they're afraid to get in a cold shower, which doesn't have nearly the same impact on cortisol. It's kind of wild how afraid of cortisol people are. People think they're going to get pushing syndrome. I don't know what the siop on cortisol was all about, but you're going to at moon face, you won't be able to lose abdominal fat. I mean, there is a real condition, which is even I know it's a cushing syndrome where cortisol is pathologically elevated, but come on folks. Like cortisol goes up, cortisol goes down. That 20, 30 fold from the morning until night, in a healthy individual. So what do you think it is that people get, like afraid of cortisol, afraid of some stress? I mean, like your hippocampus, obviously, in this case, their hippocampus got better. It's not dissolving into a puddle of its own tears. What is this? Our predecessors do wrong. Let's blame it on the parents. Because we weren't doing science communication, and what in the world was the incentive for demonizing molecules? It's so crazy. So even though his frameworks are still, potentially very helpful, some of it we can blame on Han Semy, and his general adaptation response, like the original idea that if you were chronically stressed, it would lead to true exhaustion of all your physiological systems, right? Because that was the final phase of his general adaptation response. People have conflated acute stresses versus chronic stresses. And yes, we know chronic stress be they psychological, physical, increase outestatic load, increase metabolic disease, inflammation, blood sugar dysregulation, insulin resistance, significantly associated with heart disease, dementia, all these kinds of things, right? So we know that these chronic stresses can be really detrimental to our health. But we've kind of conflated that any stress is bad because chronic stress is bad. But the way that I think about it, or I try and talk about it, is that actually, the stress response, and this is as kind of cell-year, originally described it, is stress drives adaptation. He called it general adaptation, syndrome, the general adaptation response, because what stress is, is your body acknowledging that you need to respond to some external stimulus, right? And so stress diverts resources so that you can then adapt to that stimulus, be they physical, cognitive, neurological, right? A stressor diverts glucose to the immune system, right? In an infection so that it functions better, you can eliminate the infection. And so, yeah, if you took somebody and you, let me imagine they'd call us the levels after a workout, it actually looks very similar to how it would look if you just broke in your arm, or if you were like really sick, right? But this is the body adapting to a stimulus. And like everything we've talked about here, you know, physical training, driving your replicity, that requires adaptation. And so some of that core stress response is involved in that, the release of catacletics, we talked about in the brain, right? Those are stress-related molecules that are driving adaptation so that your body can deal with the stressor better in the future. And we also know actually that there's some, where there's some evidence for the cross-stressor adaptation, particularly with exercise, right? So if you exercise regularly, you are better at dealing with other stresses, like psychological stresses, you won't, you're more robust to stresses, your mood or your cognitive function doesn't dip as much when you're then psychologically stressed. So stress is actually really important because it's the fundamental driver of adaptation. But because we know that chronic stress is bad, if you never get a chance, and that's because you never get a chance to adapt, you never get a chance to downregulate, you never get a chance to respond because it's just continuous. But, right, intermittent exposure to these stresses is really important. And so you also talked about the idea of hypostress, not having enough stress, 'cause then you don't adapt, you don't build function and response. So we just need to think about them very differently because that, there's acute stresses are incredibly important for driving adaptation. - Wait, I think of it as pick your stresser, you can either be exercise or it can be psychological stress. If you take it in the form of exercise, you probably have less in the form of psychological stress. It's obviously not completely true at a one for one, but I think as you pointed out, we and all organisms thrive on some degree of stress. I think if people are getting enough good sleep at night, - Yeah, sleep is the question. - I don't wanna say there's no limit to the amount of stress they can absorb, but when it starts to erode your sleep, that's perhaps one thing's need to be adjusted. Resistance training. Is there a particular protocol for resistance training that opens the opportunity for plasticity better than others that is supported in the literature? - Again, two different windows, say, of action. So that acute kind of arousal, and this would be, you know, you go in the gym, you do a couple of sets, you're not maxing out, you know, it's probably gonna be your fairly typical couple of sets of eight to 12 reps, kind of 80% of max, something like that, you do. - Compound movements. - So most studies use machines. - Right. - So maybe do a leg press and a chest press and a lap pull down. - Okay, a short detoy movement. - Multi-joy movements, usually with machines. - And again, if that takes 20 to 30 minutes, that kind of shows some similar effects to that, like 20 to 30 minute jog that I talked about in terms of some acute bumps in cognitive function, probably through arousal, the mild activation of those arousal pathways. Actually quite similarly, the, I mean, probably slightly higher intensity will also be beneficial as long as you're able to recover over time, that recovery is critical, just like I was just saying in terms of any kind of adaptation. There were several studies of resistance training, looking at cognitive function and brain structure over time. I say several, it's like three or four. In older adults, and they typically do two or three times a week, five to six exercises, three sets of eight to 12 reps, you're very similar. So those multi-joint machines in the gym, that anybody can do, and they're in any gym. Presses, pull ups, rowing, pull downs. Right, yeah, leg press. Hamstring, curl. Exactly. Yeah. And what you tend to see is that if you do that for at least six months, so the study's gone for like six to 12 months, you see significant changes in the structure of the white matter of the brain, and with that improvements in executive function, in particular. You want to remind people what white matter is, just for the, knit for the newbies. Very broadly, you have white matter and gray matter in your brain. And the human brain, white matter, makes up approximately 60% more than most other species, any other species. And so the wrinkly outer part of your brain, the cortex, that's gray matter, you also have more gray matter, deep inside the brain. In between that is the white matter, which is where you have the modeling sheaths on your axons, that's what allows those nerves to conduct information really quickly. Whereas a robotic exercise on that kind of intensity spectrum, you just talked about, seems to particularly benefit the gray matter, which includes the hippocampus. Resistance training seems to particularly benefit the white matter. And so you see improvements in a white matter structure, which, and changes in white matter structure with age, are one of the best predictors of cognitive decline with age, interestingly, like outside of other things you see in terms of neuropathology, amyroid, tau, et cetera. That loss of white matter structure and function is closely tied to cognitive decline over time. So you see improvements in structure and function of the white matter. And potentially improvements in something that we call white matter lesions, which tend to happen around areas of poor blood flow within the white matter of the brain. And with that, improvements in executive functions. So a robotic exercise is gray matter and memory, and resistance training is white matter and more sort of executive type decision making, processing speed type functions. We talked about lactate and some of these other things that my increase I beat enough with the aerobic training in resistance training. The, I think the primary mediator of that, or one of them, is IGF1, which is in particularly increased with resistance training. We know that IGF1 is really critical to the development of white matter, right in the womb, and then as a baby. And it seems to be also really important for white matter structure then throughout the lifespan. So resistance training is a really great way to then create these boosts of IGF1. So that's probably part of why we see that difference. But that's why you need to do both. Though they may have similar kind of acute effects in terms of cognitive function, they seem to be having very different effects in terms of the structure and function of the brain long term. I so appreciate that you're basically telling us that different forms of exercise impact different critical aspects of brain structure and function. So resistance training, white matter, cardio, gray matter, broadly speaking, and many different molecules. IGF1, BDNF, lactate, and on and on just for, what do you say in Britain? It's not kicks. They use a different word for kicks and giggles. I'll just tell you, there are sort of two running jokes in the field of neuroscience when I was coming up, which was if you desperately need a thesis, fortunately this was not a position I found myself in. If you desperately need a thesis and like it's not going well, study the effect of pretty much any compound on REM sleep, because it will reduce REM sleep. There are very few things to increase REM sleep. Very, very few, except sleep deprivation and then REM rebound. Likewise, there was a review published by a guy named Jeff Lickman and Josh Sains, who were in a different field. So they did a kind of cocky thing, but back then they were like, "They're good guys. I know them both." But they published this review about long term potentiation, We're done. They said they did a review of the literature and they said, "Basically, you can throw any molecule on a couple of neurons and do the protocol for long-term potentiation and you get an enhancement of long-term potentiation." Now, that wasn't completely true. The reason I'm raising this is that there's this theme, right? Like, there's certain processes like processes that are not that hard to disrupt, like REM sleep. Just kind of tweak the system a little bit. You see a deficit, smaller, large deficit. And then things like long-term potentiation, which is thought to underlie a lot of forms of learning and memory. In a dish with some neurons or maybe even an animal, you can knock something out or overexpress something and you get more or less longer potentiation. It's not that hard to tilt the scale on it. But in reality, the human body has tons of molecules that it deploys. And it now, to me, makes perfect sense why plasticity, which of course is the foundation of learning, sort of one in the same in many ways, is brought about by resistance training and by cardiovascular training because they're both motor. Just like crossword puzzles, certain plasticity effect, maybe less than, you know, dance where there's a number of different things that social inputs, balance inputs, and on and on. So whereas two or three years ago, I would have said, "All right. Are we really talking about exercise opening plasticity?" It always seemed like mice running on wheels and you get a few extra neurons. You get a nature paper like, "I love that work. Don't get me wrong." It turns out to not be that meaningful in terms of new neuron production, doesn't seem to be that meaningful for human memory and offsetting cognitive decline. But now I have a completely different view of exercise based on your work, based on the studies that you're describing because it's like, "Yeah, these are the big guns in terms of deploying lots of molecules that without question are interacting with one another." So I no longer think about exercise as like, "Okay, well, like it's just increasing vessel growth. You're getting more metabolic health, so then the brain gets better." I now think about resistance training and cardio and their various forms, as you point out four by four, et cetera, as like the real plasticity triggers. So that was a long-winded way of saying, "Thank you to you and your colleagues who've been doing this and thinking about things like clutch states and molecules that shift plasticity." Because I love reduction in single molecule manipulations. I think they're very important in a certain context. But for a while, it was like, "Cash, everything opens plasticity and everything disrupts around the sleeve." And like, "When are we going to get to this stuff?" Anyway, Alzheimer's Parkinson's. Nobody wants these neurodegenerative conditions. What is the current thinking about the factors that make one susceptible to Alzheimer's? I'm beginning to think that it's not just one, but then there's a genetic predisposition issue that maybe you could touch on. And what can we do besides the things that we're already talking about today to best reduce the chance of accelerated cognitive decline or full-blown Alzheimer's? First we talk about dementia, which is essentially the end stage of cognitive decline. There's some trajectory of decline that happens from your peak to that point, where ideally we'd intervene much sooner. But right now, we don't really do much until dementia is diagnosed. It's very similar. We don't do very much until diabetes is diagnosed. Ideally, we can act much earlier in that trajectory. That's increasingly being accepted in the neuroscience and neurology communities that actually we could potentially change that trajectory or at least decrease risk. So within dementia, there was an umbrella term, which is essentially the loss of cognitive function such that you can't look after yourself on a day-to-day basis. You can't do the basic activities a day living. Alzheimer's disease is the most common. It makes up about 60 to 80% of cases of dementia. The next most common is vascular dementia, although vascular dementia and Alzheimer's disease overlap a ton. The vast majority of people who have Alzheimer's disease also have some element of pathology or changes in the blood vessels in their brain, which is what you get with vascular dementia. And then there's also dementia with lube bodies, front temporal dementia, and then dementia is to Parkinson's. Lube body dementia may actually mostly be lube body dementia. But we've gone to a point now where it's generally accepted that potentially half of cases of dementia are preventable. I think the majority of that falls into those first two buckets of Alzheimer's and vascular dementia, although metabolic disease and other risk factors for Alzheimer's disease also increase the risk of Parkinson's disease and those other dementia as well. When you then think about Alzheimer's disease specifically, there's one small slice of Alzheimer's, which is like monogenic, dominant mutations that you have in either. We're most of them happen either in the presinillin genes, presinillin and one and two, or the amyloid precursor protein gene. They make up at this point less than 5% maybe as little as 1% of Alzheimer's disease. So we set those to the side a little bit. The vast majority of Alzheimer's disease is what we call late-on-to-out-simers disease, although it's actually early and earlier in some populations. Yes, as a genetic component, your apoe gene is probably your most common risk gene. It's also associated. There's also polygenic risk, so thousands of genes can give you a little bit more or a little bit less risk of Alzheimer's disease. It's much more related to lifestyle and the environment than say that they're early onset, monogenic Alzheimer's disease. The best accepted review of all of this is run by the Lancet Commission on Dementia Prevention, overseen by Professor Jill Livingston. The most recent version of this suggested that there were 14 risk factors who between them accounted for about 45% of dementia risk or dementia cases and that are modifiable. So, O-Life Education, High Blood Pressure, Diabetes, Hearing Loss, Vision Loss, Brain Trauma, High cholesterol. They recently added. High LDL. High LDL cholesterol, low physical activity. So this is all related to the things we've already talked about. Maintaining good physical health, maintaining inputs, getting inputs in the first place. High LDL education is critical. And hearing loss, as I recall, was in a more important one, in reference to inputs. Don't want sensory input degraded. Absolutely. So, hearing loss, vision loss, social isolation. They didn't. There was quite. So, two things they didn't include that were fairly controversial and were sort of debated. Letters were written to the editor and all that kind of stuff as happens in academia related to. They didn't include sleep, loss or sleep deprivation as a risk factor for dementia, even though the evidence. Particularly if you're. Didn't look at it or didn't include it. They didn't include it. So, like, they talked about it, but they felt that the level of evidence wasn't high enough, though it was probably as high as some of the other things that they included. It's a tricky one. I don't want to take us on too much of a tangent, but having looked at these data a lot, I do think that people need to get enough sleep. But some people, like myself, do fine on six and a half or seven hours and other people can do fine on only seven or eight or nine. There, a few people are a-okay all the time on just four to five hours for prolonged periods of time. But when we say not a-okay, what tends to happen with shift work or people that are chronically sleep deprived is most of the other things you're talking about get worse. Well, the y'all goes up. -Tiby, T. -He goes up. So, it's like. I can understand why they might not have included it, but it seems so foundational to me that it does seem kind of a shame. Most of it is related to how they analyze the data, so we can get to that. But in reality, when you look at the data on sleep loss and dementia risk, the cutoff is really around six hours. So if you're consistently sleeping fewer than six hours, that's where risk starts to increase. So that kind of fits. -That's about right. -Yeah, that's about right. Because I think it's the lack of those last two cycles that are remenriched. -Yeah. -Cause in the beginning of the night, you get your growth hormone surgery, you get a lot of deep sleep, assuming you're doing things right during the day. And then it's those last two 90-minute-ish cycles that you glean most of your rem. -Yeah. -And if you're not getting those night in and night out and night in and night out, sooner or later, you're going to have issues. -Yeah. So sleep was one, then the other one was nutrient status. So they didn't talk about omega-3's, B-vitamins, which we do actually have some quite high quality interventional and observational epidemiological data for. So there was kind of some discussion as well of those things should have been included. Other analyses that looked at those suggested that they potentially contribute a significant of the amount of the population of the tributal risk of dementia. So all that to say that their 45% estimate could be quite conservative. If we consider some of the other things, there are some other studies that suggest that there may be as many as there was as much as 70% of dementia may be preventable. But then you have to start including things related to socioeconomic status and deprivation of the societal factors that we know have a massive impact as well. So that's less and moreifiable like on the individual level, right? Really would require more changes at the societal level, which is kind of harder to do. -Could I ask you a question? It's going to be a very controversial one. But there are people arguing, there are very smart people, I should say, arguing that the shingles vaccine is lowering rates of dementia significantly. I haven't looked at those data closely yet, I plan to, but it certainly is intriguing, given the data that herpes viruses of various sorts have been correlated with Alzheimer's. - This comes off the back of three or four very large natural experiments that have been done in various countries. And really how you interpret these data is going to depend a little bit on your kind of risk tolerance and like what you think should be done in terms of the level of evidence required to intervene. So I'll describe the studies in a second, but some people are definitely saying, you know, if you want to say that the shingles vaccine decrease the dementia risk, you have to have a clinical trial that's adequately powered to show that and there is a trial like that being planned currently. So the studies that have happened so far, there's one in the UK in Wales, one in Australia and one in Canada. And in each of those countries, what happened was that on a single date, a huge tranche of people became eligible to get the shingles vaccine, whereas if they were born one day earlier, they weren't eligible. So you get what you call like a natural experiment, where from one day to the next, those people shouldn't be that different otherwise. And they showed that rates of other diseases weren't that different rates of uptake of other, healthcare and other vaccines wasn't that different, but there was a big shift in the uptake of the shingles vaccine. And so what they essentially consistently showed across all those different populations was that those who got the shingles vaccine, or were eligible to have the shingles vaccine depending on whether they had access to the data on whether people got it or not, had a decreased risk of dementia. And that was consistently seen across those three groups. All those three trials used an older version of the shingles vaccine called Zostervax, Zostervax, which was a live attenuated vaccine. There's now a newer version called Shingrix, which is a recombinant vaccine. And there was a study down in the US that compared people who switched from, you know, there was a similar switch from Zostervax to Shingrix, and it and saw that Shingrix was associated with a lower risk of dementia compared to Zostervax, although both were associated with a lower risk than none. When you look at some of these trials, or studies, 'cause they're not trials, people have made a very fair comment, which is that when you look at the trajectory of dementia over time, you look at something called a Kaplan-Mayer curve. So it's like a survival curve. So like every time somebody gets a case of dementia, like the line goes up, and you look at the trajectory of the two lines, those who got the vaccine or not, they diverge very early, which kind of says that, oh wait, it only takes a couple of months to kind of see this difference in dementia risk, which you wouldn't really expect based on like the natural course of dementia takes years to happen. So this is very common in these kinds of studies, and it's due to residual confounding. So there's like something inherently different about the populations that may be driving some of this different, right? They were gonna get less dementia anyway. And so maybe the Schingles vaccine isn't having that big of an effect, but I would say that having looked at all those trials and all those data, I'm fairly, you know, I'm convinced enough that there's a signal there. There should be a randomized control trial that's happening, but there was a number of reasons why this might be the case one. It obviously we know reduces cases of Schingles. Schingles can be very painful. It can change how people interact with the world. You stay at home, you don't feel good, you're not paying for a long period of time. That can go for many months as rare for it to last many months, but it can last a long time. Then, you know, they've hypothesized in some of those papers that the magnitude of the reduction of dementia risk didn't map perfectly onto the reduction in cases of Schingles, right? There had to be something else going on as well. They've suggested that it may be due to like an immunomodulatory effect, it may be because you're also suppressing other viruses like herpesimplex virus that we know may also be associated with certain cases of dementia Alzheimer's. And the reason one of the arguments for the immunomodulatory effect is because not in all the studies, but in most of the studies, there's a slightly bigger signal in women than there is in men. And it may be that that sort of meaning it's more effective in women than it was in men. And we should mention that the Schingles virus lives on neurons. Yes. Yeah. The herpes viruses tend to live on neurons and they hang out on neurons, which is why people who, you know, get herpes one infections will get a cold sore at a particular location that will come back because it's living on the trigeminal nerve. There's just, you know, I think people don't often understand that viruses can, you know, harbor and particular cell types. Yeah. And so the logical link between herpes viruses and dementia risk is, you know, it's not, I mean, that alone is not a causal relationship, but it makes sense mechanistically. Yeah. And a fundamental feature of herpes viruses is they generally don't kill the neuron. They can, but that's why they stay alive. These viruses are very smart. They know how to get, infect their host, but not kill their host, which is what really smart viruses do. Yeah. So what age are people getting the shingles vaccine? The study is actually quite late. It's like people in their 70s and 80s. Oh, wow. Yeah. So again, it would be very fair to argue that getting it much earlier, we don't have any evidence for it because, you know, in reality, in these, particularly in these, the studies like the UK, this is done in the National Health Care System, it was, you know, for the highest risk older, older adults. And so getting it in your like 50s or, you know, mid 50s, which is sort of the guidelines in the US, that yes, to reduce shingles absolutely, but it doesn't map onto the dementia risk age that was seen in these studies. A final piece of this that I think is important and kind of goes beyond just the shingles vaccine is that if you want to maintain function over long periods of time, one of the best things you can do is minimize your chances of getting really sick. There have been several studies. One was the adult changes and thought studies on the University of Washington and Seattle primarily. This is a similar thing was shown in the Rush memory and aging project. But basically, when you look at the same individual over time and you measure their cognitive function every few years, which these studies did, cognitive function doesn't just decline sort of linearly or steadily with age. It goes down, you know, a little bit on average, but the biggest decreases sort of happen stepwise after periods of significant illness. And so like in the adult changes, the thought study, those who'd been sick in between, had a major illness in between having their cognition retested, they had a step change down and those who were hospitalized, that step change down was even bigger. So you could talk about how people maybe could have changed things in order to recover some of that function afterwards. I think that would have been possible if you thought about how you might intervene. But a major, I think it's a reason to say, if I can do as much as I can to minimize the chance that I get really sick, because what happens then is I'm at home, I'm not receiving any stimuli, any inputs, I'm not moving, I'm not eating well. Obviously, there's all the downsides of the infection itself. Then, if I can avoid that as much as possible, then over time that could lead to greater benefits, right, change the overall trajectory. So I think that's one reason why some of these vaccinations could be beneficial is just you're minimizing the time you spend really sick as your older, which we've seen as a result in these sort of like step changes down in cognitive function. Fascinating. I realized that we could and probably should do an entire podcast about traumatic brain injury and concussion, but as a teaser for that, are there anything that people should do and/or take in the immediate aftermath of a head hit? Now, I'm not talking about hopefully people are getting checked out for brain bleed and things like that. So I'm talking about moderate concussion. So I've got their quote-unquote bell rung. They slipped and fell. They got clipped in soccer practice. Their kid's a little dizzy. Now, of course, somebody young or old is vomiting or not able to sleep or real issues. I mean, everyone should probably be checked out in the first case. But I get asked this question all the time. Is there anything that people can take to get over mild concussion or moderate concussion? The evidence based on this is a little shaky. But I think for most things, it kind of fits into this idea of positive asymmetry, low risk, high potential for benefit. And there have been randomized control trials to kind of look at some of these things. So a couple years ago, we published a paper looking at different nutritional supplements after concussion that we have some reasonably good evidence for. So yes, you should be seen by a doctor. You should get whatever scans and immediate medical care that you need. Absolutely. That's resuming all of that is done or will we done? lead. Yeah. Immediately, there are a couple of things that I think we know from animal studies that translate fairly well onto humans, but also some, maybe some observational studies in humans, but a couple of things are important. So one is temperature management, temperature regulation. There have been, this is what my PhD was actually in hypothermia after acute brain injury. Hypothermia. Hypothermia. Yes, so cooling down. Although I did do some studies where we heated up and that makes things worse. So this kind of pertains to what I'm about. What I'm about to do. Brain doesn't like to get too hot. Essentially what I'm about to say. So there have been lots of studies where they've done cooling, hypothermia, in people after traumatic brain injuries and concussions, hasn't really shown much of an effect. What seems to be important is preventing hypothermia. So one of the effects of cooling somebody down is that they don't get hot. So that's probably something that's really important. So often concussions happen in a heat stress environment. You're on a football pitch. It's August in Alabama's 40 degrees, right? Get inside, get cool as quickly as you can because there are studies that, and that doesn't mean you have to get an ice bath. Just don't be really hot. If you get a fever, which you might do after a more significant injury, you know, Tylenol or something like that to help maintain thermal regulation will be really important. The next is blood sugar regulation. So we know that after a significant brain injury, you have increases in blood sugar. That's associated with worse outcomes. Some of it's like, what's cause, what's consequences? The injury driving the blood sugar is the blood sugar driving injury. I think an easy thing to just say is I would avoid any super sugary refined carbohydrates that might just sort of, you know, kind of pile on for one of a better word, right? So alcohol. So alcohol, I would avoid as well, mainly because it impairs sleep. And we know the sleep is going to be critical to recovery. Some people would say something similar about caffeine acutely after injury because it's a it's a stimulant. One thing that with the reason why hyperther, I mean, you're getting too hot makes the injury worse is because it, you know, simply speaking increases the gap between energy requirements and energy production. So like one of the hallmarks of these acute brain injuries is a deficit in energy production with me and myzconjure failure or myzconjure dysfunction. And so if you get too hot or you stimulate the brain, you're asking for more energy when the when the when your neurons can't produce it. And that is a trigger that kind of deficit in energy production is a trigger for cell death and neuroinflammation. Some of these other processes that then may happen. So avoid alcohol, avoid caffeine, both of those potentially related to improving sleep. Then things that we have some, you know, reservoir evidence for immediately after concussion or creatine. A word dosage. The best trial was actually done in a paediatric group, although very broad. It was like one year old to 18 years old. But they gave 0.4 grams per kilo per day. So whoa. Yeah. So it's a pretty it's like double a traditional loading dose if you're a 100 kilo person. But like if you're 70, if you're 70 kilos, you know, 155 pounds or something like that, then that's 28 grams of creatine. So like it's a lot, but you know, trips in the bathroom can be expected, but you may just spread it out across the day, right? Yes. So well, one thing I'll say about that is the most recent metanalities show that you actually don't get is actually quite rare to get more GI side effects with creatine compared to placebo. Some of it is probably related to the quality of the supplement. So poor quality creatine supplements have more adulterance that may cause some of those GI side effects. Some of it is can be due to high. You can saturate the creatine transporters. It doesn't get absorbed. Water gets drawn into the gut that can that can then go right cause diarrhea or something. But some of the GI issues that people experience are probably due to poor quality products that they're taking. For the nonhead injured individual, is there any reason to go back to the old loading protocols of taking 20 grams per day, putting it in a little bit of grape juice or something else to spike blood sugar for this very reason that it could augment the passage of creatine into your cells as opposed to drawing water into the gut. In the 90s, we would take five grams of creatine four times a day in an answer to of pure grape juice. And you draw a lot of water into your muscle cells. You put on, you know, it varies, but for me, anywhere from five to eight pounds of water weight, but it's mostly in the muscles. It's not insignificant. It translates to big strength increases. I don't take nearly that much now. I just do the 10 grams per day, but is there any reason to go back to those traditional loading? So if you're just like long term creatine supplementation, probably not. In this kind of setting, I think the evidence is for a loading style protocol, right? So for most people, it might be 20 to 30 grams of creatine spread across the day. For anybody who's just taking creatine for other reasons, this is a standard dosing protocol that I think is fine. I don't know. I thought you were going to tell me I could get it to work that way. So the, some of the studies that use traditional like creatine monohydrate and look at creatine levels in the brain, they did use a loading protocol for a week and then you see significant increases in brain creatine. But creatine having other effects on the brain, potentially improving mood, improving memory and in older adults, some of those benefits happen at just like a traditional creatine dose. So you don't need to take massive dose, you know, load loading doses. You can actually see some benefits of like five to 10 grams. So that's creatine. So magnesium. So 400 milligrams once or twice a day, there've been some trials that shouldn't work for those studies actually use magnesium oxide, surprisingly. But I would probably use magnesium glycinate. It's very bioavailable. Athletes usually need a bit more glycine anyway, but any bioavailable form will be fine. Then I make it to be fatty acids. The evidence is a little bit better for like, there were now several studies in like in like a collegiate American football players where they take a couple of grams of omega-3s every day and across a season, you see less accumulation of biomarkers of injury like neurofilament like that is circulating in the blood. So that's something that I would just take like long a journey. If you're somebody who's at risk of a concussion because of your sport or your job, I would just take a reasonable omega-3 supplement just long term because we have some reason evidence for that. Then other things might become a little bit specific to the symptoms of your experiencing. So if you have sleep issues, then there's studies that have used a metatonein and that's that's shown improvements. Branch chain amino acids at high doses for sleep. And that's interesting because outside of TBI, high doses of branch chain amino acids may actually impair sleep because they compete for tripped fan uptake into the brain, decreasing, potentially decreasing serotonin, melatonin production. But in TBI, there are two studies that suggest improvements in sleep with high doses of branch chain amino acids. If somebody's going to take branch chain amino acids, presumably they're going to look at how much loose scene is there for a variety of reasons. So do you recall how much loose scene to get this effect post TBI? So I don't think they, at least I don't remember the loose scene dose, but they were taking up to 60 grams of branch chain amino acids. -60. -60. -60. -60. - Okay, because a typical kind of suggested supplement bottle gym dose would be three to five grams. That's usually about six capsules. - Yeah. - So like one study they did in veterans, they had, I think it was three doses of 20 grams, of course, per across the day. - Are you curious about these, I began studies that are looking at TBI and brain recovery. I mean, I began as a whole other thing because it's the most powerful long-lasting psychedelic, at least that I'm aware of. But it seems like there's some interesting data coming out. - Absolutely. And then in people with a history of brain trauma and PTSD, and I think some of these other psychedelics are going to be very interesting there as well, potentially due to their neuroplastic effects that tend to particularly happen in macro doses, in the psychedelic doses. I think that there's a lot more to come there, but certainly the trials have been done so far are quite compelling. But that's obviously in a very controlled kind of clinical setting. - Yeah, you'd be heart rate monitor. - Yeah, I began. It's not legal in the United States, although things are shifting. - Coalene is another thing, particularly our citricoline. So best evidence is for one to two grams a day of coalene. - Of coalene. - In the form of CDP coalene or citricoline, which is the same thing. Those are the main ones, then there's some other like niche supplements that do have some evidence, the one that's probably the most evidence for it is Boswellia. - Boswellia? - Yeah, which is Indian frankincense, but there's an extract of Boswellia that's been tested in, I think, three different clinical trials after TBI showed some benefit, Enzoginol, which I think is a pion extract, slightly less evidence than Boswellia. I typically would recommend people stick to the first group of kind of nutritional time supplements, but in very specific use cases, based on specific symptoms, some of those other things might be beneficial. Then beyond that, we know that physical, physical activity as soon as possible is really important after getting another head injury. - Without getting another head injury. and so this really changed over the last two years. few years, maybe five, 10 years ago, people like rest is what you need to do, go lie in a dark room. If you've got a concussion in sports, you would expect the team to have a rigorous return to play protocol that included low level aerobic activity as soon as you're able to tolerate it. Two or three times a week at a level just below what might make your symptoms worse. Then first you do non-specific aerobic exercise and then you start to bring back skills, specific exercises, sports exercises, then go back into full training and then go back into playing, kind of it in that order. There should be quite a system of ties now, so I would expect sports teams to have that in place. The standard of care is generally physical therapy. If you have any ongoing cognitive or physical symptoms, a month plus after any traumatic brain injury, there's some evidence that virtual reality or augmented reality physical activity might improve cognitive symptoms, vestibular therapy for balance and disinist issues, and then increasingly there's a focus on sort of ocular motor training for convergence or other eye issues that are very common after concussions, but aren't picked up as often as people might like. But increasingly eye tracking and these kinds of things are done, particularly in professional sports or other arenas after brain injuries, to ideally have a baseline, you figure out what's changed and then you would track that over time. You can train that depending on the deficit. Those recommendations are going to be extremely helpful for people, athletes at all levels. I mean, I think for people that don't have access to all the latest and greatest technology and coaches and nurses and doctors that there's a lot of head hits out there that aren't necessarily, fortunately, aren't full-blown brain bleeds and brain damage, but the low level trauma to the brain is obviously a consideration, especially kids like just falling off the monkey bars. Like parents want to know what they can do. So thank you very much for those recommendations. You're doing a strong man competition. All natural. This is not the enhanced games. Just tell us what the format of that is. Well, first of all, how old are you? 41. Cool. Have you done one of these before? Yeah, six or seven competitions at this point. I started during COVID. I've done like a competition or two every year since then. Your tall guy, you're like six, two, you weigh like two, ten to fifteen usually. And is it so it's heightened weight class or just weight class? So it's weight class. I know. So now that I'm all in the 40, I compete in the master's category. So there's one of my favorite things about strong man is that if you weigh less than 200 pounds, you're a lightweight. So I'm in the lightweight master's category. It means that I usually have to do a water cut for a weigh-in because I don't normally above 200 pounds. Yeah, they have weight classes and age classes. Can you eat your weight and hydrate your way back up to after a year? Usually weigh in 24 hours before. I'm definitely back to my usual weight by the next day. Gotcha. We don't want you trying to lift heavy things dehydrated. What are the big events? Are you carrying stuff overhead? Are you carrying stuff at your sides? What are you doing? A standard kind of local regional competition is five events. I qualified for the natural world strongest man, which is going to be seven events. But there's usually some kind of deadlift, some kind of overhead pressing event, some kind of medley where you're carrying something, lifting stones, farmers' walks. So in a truck pull, something like that, so more dynamic. So there's usually a static max strength thing, but then also more dynamic. You do the teeth pull? No teeth pudding. We didn't talk about oral health and cognitive function, but that's really important too. The events in the competition that I've got coming up, the world's strongest, there's going to be a farmer's walk. So that's where you just pick things up at the side and kind of. For a guy, let's say you hydrate back to like two or five, two ten, or something like that. What's a good distance and weight to carry? I know the weight in the competition. It's 120 kilos per hand, so there's 264 pounds per hand. And as far as you can carry it. That's a big human in each hand. Yeah. So typically, if you can get to where you've got your body weight in each hand and you're able to pick it up and move with it, even if it's not very far, I think that's pretty good. Some people might say half your body weight. In reality, if you pick something up, heavy a move with it, that's great. And then get better. We're not talking about combinations. This is your time to shine, my friend. People can work their way up. I watch Tom Havelins Instagram. We'll put a link to it everyone to see that. His wife and his kid also work into the workouts. He's got a man. He's strong. But yeah, carrying heavy weight. No, no, this is not your time to tell people how to tip toe into it. That's a different five guess. So you're carrying 220 pounds in each hand. 260 pounds per hand. And walking how far? It's maximum distance in. I can't remember for 60 or 90 seconds. You can set it down. You can set it down. So as far as you can get in that period of time. And then be similar with the yolk walk. So there's a yolk where you put it on your back. It's 700 pounds. How far can you walk in that period of time? There's so primitive. If you're hypotheramic event. So in that event in the yolk walk, if you get to the end, I think it's 30 meters, 90-ish feet. If you can carry that and that far in the time cap, then you do reps on a circus dumbbell. So there's this big massive dumbbell that you have to like, show it to overhead. There's one at 110 pounds and the next is 135 pounds. Then there's going to be a loading medley. So sandbags and kegs, like over a platform that's like, I think 200 to 300 pounds implements. They kind of increase over time. There's a maximum squat. And you have a choice of two different weights. And so like if you choose the bigger weight and you get reps on the bigger weight that you get a better squat than somebody you did. Just stand back. It's a standard back squat. It's with an axle bar, it's like a thick bar. And then in strong man, when you have squatting, you usually have pads that you squat down to. So this is a specific height you squat down to. So that could give you an advantage of your shorter. Because you have to go less distance to get the weight on the pads. There's no geeking it and calling less than a one. No, people have done that. It doesn't look good. Yeah, no, no. It just has to hit the pads and come back up. The weights are 170 kilos and 200 kilos. So that's what? Nearly 400 pounds and 400, 40 pounds. Log press for reps. And again, it's a similar style. And I think it's 100 kilos, 220 pounds and then 120. So 264. And then there's a sled. The push of sled. And then you load it with a 275 pound sandbag and then you drag it in a time cap. I think that's all the events. Awesome. You'll let us know when it is. Yes, it's at the end of August. Cool. Will it be online? I won't be online, but I'm sure there'll be some stuff on Instagram. Cool. I love that you do this. Clearly, you got a lot of brains in that skull here. And you're also super strong. Love hearing it. That's great. And you have no excuse not to carry the groceries at home, right? You lost that. That right. But there's no doubt you would. Anyway, that's awesome. I'm very impressed by the by people who continue to take on athletic challenges in their in their adult life, which is very appropriate to context today. So Dr. Tommy would thanks for coming out today. I learned a ton from you. And you know, going into this, I like to think I know a thing or two about plasticity, having spent so much time in it and studying it over the years. I learned a lot from you today. And I know everyone else did as well. You're an exceptionally clear communicator and you're working on not just an important issue. You're working on the issue. This neural plasticity thing and a whole lot more. So let's definitely get you back to talk about recovery from brain injury and stroke and things that. There's a lot of additional things I think we could dig into. But meanwhile, you've given us a lot of actionable tools. And yeah, I love that you're doing the strong man competition and come back again. We appreciate you. Thank you so much. Thank you. Thank you for joining me for today's discussion with Dr. Tommy Wood to learn more about his work and his book. Please see the links in the show note caption. If you're learning from Endor and join this podcast, please subscribe to our YouTube channel. That's a terrific zero cost way to support us. In addition, please follow the podcast by clicking the follow button on both Spotify and Apple. And on both Spotify and Apple, you can leave us up to a five star review. And you can now leave us comments at both Spotify and Apple. Please also check out the sponsors mentioned at the beginning and throughout today's episode. That's the best way to support this podcast. 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