Muse

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 was 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 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 BetterBrain, 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 and 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 and 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 discussed 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 Dementia and Stay Sharp at Any Age. 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 any age. 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.

I mean, this is my favorite topic in the entire world. What is more interesting than neuroplasticity, right? The brain is so interesting, but its 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 lives.

you have an eclectic research tapestry right 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 uh yeah yeah uh

does that mean lifetime no no gear lifetime well it's tested uh i yeah life

time no gear for me personally but it's a drug tested version of the strongman sport so yeah if you uh if you compete in natural strongman then you you get tested great so we'll we'll talk about

that i'll resist the temptation to talk about your two boxer pups 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 right 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 that's a massive part of brain development in the first place and this is a process that's essentially continuously on ongoing and you can think of it as its primary role is so that you can navigate survive the world around you and that's through learning skills through remembering people and things and facts um and where i one of the 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 uh conflated neurogenesis and neuroplasticity so when we're thinking about brain development we're thinking about um then also brain function over with age and either cognitive decline or maintaining cognitive function we thought that the adult brain was was fixed right um 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 um confused about is the fact that the adult brain does not make new neurons in many places right maybe in the olfactory bulbs in the dentate jars of the hippocampus tiny tiny yeah but like compared to the rest of the brain they're not you'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 you 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, right? 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 the same cells you were 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 um practice billiards and i'm okay now hang in there but let's say i want to get really good as i learn and get better and better can we reliably say that uh 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 there's certainly it requires both right the either development or strengthening of new connections and then the removal of other connections that decrease accuracy say or 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 has kind of finished developing new 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 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? 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. I still toil with this when I look at the literature on neuroplasticity and aging, right? Like, yes, use it or 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 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 so everything about maintaining cognitive function later in life you definitely see that those who continue to engage in hobbies and activities that are cognitively engaging or cognitively demanding and that can be lectures that can be volunteering that can be you know 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, you know, they've already been doing, right? So 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 coordinative movement or exercise you see the same things with like 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 pointer trial that was here in the u.s 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 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, an 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. already doing well with mental health, physical health, and performance, it can make you that much better at any and all of those things. It's meant for anyone interested in achieving better health and vitality. It provides a deep dive into and clear explanation of tools to improve your sleep, nutrition, exercise, focus, stress management, neuroplasticity, and motivation, and much more. I'm truly thrilled to share protocols with all of you. The launch date is September 15th. You can learn more about it by going to protocolsbook.com. That's protocolsbook.com. I'd like to take a quick break to acknowledge one of our sponsors, David. David makes protein bars unlike any other. Their newest bar, the Bronze Bar, has 20 grams of protein, only 150 calories, and zero grams of sugar. I have to say, these are the best-tasting protein bars I've ever had, and I've tried a lot of protein bars over the years. These new David bars have a marshmallow base, and they're covered in chocolate coating, and they're absolutely incredible. I, of course, eat regular whole foods. I eat meat, chicken, fish, eggs, fruits, vegetables, etc. But I also make it a point to eat one or two David Bars per day as a snack, which makes it easy to hit my protein goal of one gram of protein per pound of body weight. And that allows me to take in the protein I need without consuming excess calories. I love all the David Bronze Bar flavors, including cookie dough, caramel chocolate, double chocolate, peanut butter chocolate. They all actually taste like candy bars. Again, they're amazing. but again, they have no sugar and they have 20 grams of protein with just 150 calories. If you'd like to try David, you can go to davidprotein.com slash Huberman. Right now, David is offering a deal where if you buy four cartons, you get the fifth carton for free. You can also find David on Amazon or in stores such as Target, Walmart, and Kroger. Again, to get the fifth carton for free, go to davidprotein.com slash Huberman. Can 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 Maintain Your Brain study was actually, it was 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 individual. So they had a dietary intervention, they had physical activity, they had progressive behavioral therapy for those who had some potentially some mental health concerns, and then they had online brain training. There was something similar done in the POINTS 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 the points trial is a good example. They did, they used the platform called Brain HQ. Brain HQ. Brain HQ, which was developed based on the work of Mike Merzenich, who's, you know, like one of the godfathers of learning and neuroplasticity, right? um and they do various tasks primarily focused on developing and maintaining processing speed um some of that evidence goes all the way back to an older trial called active that was done in the us in the 90s it's still the biggest ever trial of like pure cognitive brain training again in older adults so 60s and 70s they had three different um training groups the and then a control group uh the training groups did memory training and kind of like you know mnemonics memory palaces that kind of stuff to help them remember there was reasoning training which is 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 flash 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 ACTIV trial that showed that those who did processing speed training with booster 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 cholinergic signaling in the foreground. um which we know is susceptible to um the processes of dementia so in particular it's this training uh 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 the main one but you can do it in sports and music and

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, you say 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, and there were 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 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 just 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're seeing. Actually think. you actually think 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 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 um 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 um so requires you to actually think and you know remember process the information rather than just like responding to a stimulus so for people that want to jump to the okay what do

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, you know, 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 love 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 what is the things that you currently do right so like crosswords are a good a good example even if you're doing hard ones if you look at the work of people like uh gloria mark the things like crossword and sudoku they're less of like a true cognitive challenge right it's it's 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 uh whereas if we're trying to build capacity you need to spend some time doing something where you are both focused and challenged um cognitively so that can come from um learning new skills be they motor language social um and ideally as broad as possible because you're going to get better like overall stimulus as well as kind of like broader potential for transfer into other areas of daily 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 involves a wide variety of tasks. So I'll give 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 faster and harder and harder, the better you get. So something like that creates a much broader stimulus than, you know, 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, you know, 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. Whereas some of these broader, more complex, ultimately more human skills probably give us a 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. Yeah. 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 sports 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. But 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 for kind of end of year 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 that they clap so they don't make noise. So they, it was a 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. Yeah. 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 like the things that you mentioned earlier, so you, cause you mentioned exercise and then skills, right? And so you could do those things separately, right? I would, maybe we'll get into 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 um and so you you would rather say learn a new language right which we have so 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? Learning a new dance.

Solo or with someone else? I'm sorry, we're half 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 of physical activity. It's fun. Of course, the best evidence is for ballroom and line dancing, which generally requires, And so there are meta-analyses of these interventions in older adults showing that ballroom and line dancing have the greatest effect on cognitive function. And so both of those require other people, as well as learning, you know, various sets of movements. So you have skill learning, you have social interaction, any other 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 of evidence behind it. but then i think you know in the exercise realm you've got all the sort of ball sports board sports team sports um i think skateboarding would be a great example as long as you wear a helmet and don't hit your head uh too often you know most martial arts again as long as somebody's not punching you in the face too much something like brazilian jiu-jitsu exactly so like you're um 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 uh responding reacting to the environment or your opponent uh 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 um you know network stability and function in the brain particularly the networks at the front of parietal network that we know is really important for like focus and attention and its function does tend to decrease with age um so uh things like like creative or visual arts um some maybe some similar effects of learning a language um again um uh 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 um you know solve complex problems you know react quickly to a changing environment that that kind of stuff so that's you know eight or nine different things that that somebody could try and And just one of those, I think, is 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. Thank you. 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 feel motivated and interested to learn. Dancing by oneself has a lower shame quotient. Well, the shame quotient, I think, might be important, right? There's the discomfort of making mistakes, and we know how critical that is for learning. And so 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. you know so a few uh years ago i wrote a paper with my colleague josh turknit about this idea

that um 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 neuroplasticity 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 gonna suck at dancing right i imagine that i'm gonna take my wife to to a tango class it's something i've always wanted to do but when i go in the first time i imagine i'm gonna be like arnold schwarzenegger and jamie lee curtis in true lies do you ever see that movie but anyway so right at the beginning they're like they're spies and they're doing the tango at this you know like gangster's mansion or something and it's like he leans over she grabs the rose from the table in her in her mouth like i'm gonna try that i'm gonna drop my wife and she's gonna hit her she's gonna be mad at me and lots of people are gonna see and i'm gonna feel stupid right and so that's why we don't do those things but it's so critical to driving those processes of neuroplasticity that we make those mistakes that we have to kind of let go of some of that that we feel as adults like We think that everybody expects us to be good at everything and the best at everything, and we shouldn't fail, we shouldn't make mistakes. But as you've 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 over 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 Ferriss, as I recall, talked about this in one of his books. He was a competitive tango dancer. Yeah, he learned tango. And that 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 salsa, tango, typically this is you know traditionally the male leads um 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 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 other men you know and then you you until you learn so that this 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 correct me in the comments but as i recall that's the story so there's that um not that following is is trivial it requires some skill But if the person, 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 who 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 can make up stories about chemicals and maybe we should because they're likely to be true. 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. that i don't think i would make up anything about 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 there's like core need 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 um you know related to mental health it could also be related to physical health right because we think about physical and and um cognitive

or, you know, stressor, psychological related challenges and the process of overcoming them, because that's what really drives, you know, a lot of physical or mental psychological growth. And I think that's something that, you know, 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 prove to yourself, hey, I'm capable, I'm able to overcome challenges, I'm able to, you know, engaged and and do difficult things and i think the psychological benefits of that you're just that process of engaging with a challenge overcoming it uh working hard to do that um i think that's just you know 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, you know, focused time working on it. If it's too hard, you can have the opposite effect, right? Like making something so difficult, somebody can't do it and they just fail again and again and again and again, right? That can obviously have the opposite effect. But something that you know you can get better at, you know you can work on, you can see progress. I think all of that then has all these knock-on effects.

Maybe we could talk about flow for a second. You know, one of the most bastardized terms in neuroscience, performance, psychology, and the rest. When Csikszentmihalyi 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. But 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'd 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 Steven Kotler and others who have written about it and studied 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 Fight Club and everything else is that suddenly we're just gonna be endowed with these powers just because we want them and need them. and that is not how it works yeah 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 like right at the edge of your capabilities but you're still managing to maintain um maintain function whatever whatever skill it is that you're performing at 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 um flow is one version of your of your of being able to you know perform at the best of your abilities if 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 um you are still at the optimal level of arousal right if we 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 um they performed well they won they you know 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 like that's a clutch state and people can perform at the best of their abilities in clutch states um and you know even though they're not in flow it's not all come into them easily right It requires them to like 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 like how, you know, athletes perform in the moment. The other side of it is that some people have intimated that flow is required for learning or like optimal learning happens in flow, which 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 because of the friction, the mistakes and the errors that come from that. So I think 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 no no it's in the sports

psychology literature they'll talk about that's why I haven't seen it yeah 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 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 it's there's real challenge you're not you're definitely not in flow yeah uh fantastic clutch state everyone uh learn it know it embrace it um live there for some period of time in your life across your lifespan uh and you'll be better off i i mean that maybe we could drill into this a little bit more because you know several times on this podcast or more we've talked about the anterior mid-cingulate cortex the structure that you know maintains size and superagers who take on hard things and you know 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 parvizzi 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 than certainly than 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 into 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, and 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 wingsuiter, Red Bull high performance team came on here. He suggested a podcast that I'm now suggesting. 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 turned wingsuiter, 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 is like, all right, I've mastered this thing.

Now put me in a situation or 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 people might talk about virtuosos in a skill just because they're so much better than everybody else. But that definition requires a specific scenario and moment of performance.

So then that sounds a lot like how I would think about flow, right? And so when you look at some of the classic descriptions from individuals who've been in that kind of level, so like there's this one from, so I do a lot of work in Formula One. So there's one from Ayrton Senna where he's- From who, I'm sorry? Ayrton Senna. The driver? The driver. Senra. Yeah, Senna, S-E-N-A. Senna, excuse me. Ayrton Senna.

Senna is David Senna, the great podcaster. 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 Senna. Ayrton Senna, 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 Monaco Grand Prix. and basically what he describes is that he's like going faster and faster and faster he's like this is beyond my capabilities like he doesn't feel like he's actually connected to doing the thing it's just kind of like happening it's exactly 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 um in that under that kind of definition and so like that 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 constantly, but I love this notion of the clutch state 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. Twyla Tharpe, who's in her 80s, a world-class choreographer, sat in the chair that I'm in and described 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 maintain which raises a question do we always need to maintain practice the fundamentals

before i answer your question i think there's there's another useful thing just kind of to remember that relates to all of this from you know in um you know athletes and sports particularly on the training side there's this general idea of thirds right a third of your sessions training um 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 um a third will just be average right and a third are just going to suck and you just have to show up and get it done but this is all in the same day or this no no just like across across the week across months across years right this stuff undulates and the 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 neuroplasticity. 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 over time. And sometimes it is a grind. And that's, 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 that you're that you're thinking about um because sometimes the skill that you're performing the fundamentals are kind of baked into that in in some way so it kind of depends on what the what the fundamentals really are maybe you know if it's um so i i'm thinking about one specific study that was done in in pianists um so this is kind of it was kind of related to the ericsson studies in uh in violinists right but this time they were looking at uh pianists and so they had four they had four groups uh 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 um german like music conservatories um and then they looked at um sort of basic skills related to um you know moving the fingers and other things that you would do playing the piano and um so they were like 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 sort of like basic functions and maybe right when you're playing very complex piano pieces you're encompassing all those fundamentals anyway right you don't need to You don't need to like do your you don't need to do your scales every day because some of that stuff is kind of 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 just like, you know, the warm up, maybe part. Maybe that's routine. Right. This is me getting in the in the mode of playing a complex piece. But then maybe some of it is just kind of helping to maintain those fundamental skills.

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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, you know, 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, right? 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 right 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 um cognitive work right you're being you're focused and highly challenged as you might be if you're a um you know a future virtuoso on the violin and you're trying to you know really practice and push yourself you can only really do that for you know chunks of 20 to 30 minutes maybe a couple times of the break right so that's why pomodoro even though there's no like good studies on the pomodoro technique like those time periods you know 25 minutes for 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 size 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 like I'm not trying to boast 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 he walked my dog, you know, 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, Ooh, okay. In the periods of time where I definitely pushed to the six, eight, 10, 12 hours of just nonstop work as a deadline approached, there was a compensatory drop in output after after you click send and so i i think you're right they're right 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 yeah do you ever give yourself uh forced constraints to get real work done not to force it i will say that

um 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 something because like nowadays you're you know close slack i have slack teams my lab and i uh we uh interact on you know message 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 return to gloria mark's work she wrote an excellent book called attention span if anybody's like really interested in this um but you get used to a pattern of distraction such that when you're um not actually being distracted you will distract yourself right um and 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 the you know around about now i'm somebody would text me or send me an email and i'll 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 if you have periods where you're not getting constantly distracted so i will eliminate notifications um but at least for me what i found is that if i if i have a ton of friction in terms of trying to get something done i will usually step away from it um 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 uh i'll usually switch over to to something else which is also kind of a normal it's it's it's one of a 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 uh you know this often happens with a with a grant deadline or you know when I was writing my book and there's a you know a book deadline and you know I've got to get this to my editor in um however many days or hours I tend to just not need to to eliminate those things because I'll I'll just I'll just focus in like I don't feel that kind of draw to be distracted by other things but that usually only 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 in the bag? We would just remind people that if you're, 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, et cetera, really suffers. So that means that the brain is unconsciously expecting a call, sort of waiting for it. And the way you describe this attentional break expectation thing, um that we get entrained to interruptions is uh really interesting um maybe this is why meditation is such a useful tool for improving focus is that it's just a forced no breaks yeah 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 i don't routinely meditate but um unless you have some part 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 um you know that's kind of you know the classic is you can't with your best ideas in the shower, right? Because actually the time when you don't have your phone on you and you're not watching TV and you're not doing all those other things that, you know, at the, at the,

the same time so maybe yes that's not what meditation is formally for but it could potentially be beneficial if your if your mind's going to wander you know making new connections um you know coming up with new ideas having that space and time to do it you know could potentially be

beneficial too in these studies these large-scale uh trials what was the diet intervention can we distill it down to some things that um 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. It 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 had a lower risk of later dementia. It wasn't an intervention when it was first developed, but that was kind of the version. It was kind of a combination of the Mediterranean diet and the DASH diet, which is like an antihypertension, 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 used in the SMILES trial, which was the first randomized controlled 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. It was published in the New England Journal of Medicine a couple of years ago. and they compared uh the mind diet to standard caloric restriction and actually they saw similar benefits in both 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 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, you know, olive oil or food group where 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, they're nutrient dense rather than avoiding any you know you have to eat 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 the parts of diet that i think about are the you know 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 diet versus 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, um, across different populations. There was, um, there was a one group that looked at different, um, tribes in Bolivia, the Bolivian Chimane, who are a hunter-gatherer group, the Mosetan, who are kind of an intermediate group between sort of the Chimane 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, um, 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 calorically restricted your brain is smaller um because you just don't have the resources to invest in you know the structure um 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 um you know and you know potentially what comes with it um 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 caloric restriction happened in that in that trial compared to the mind diet was that you know people's cognition improved just because they decreased their energy intake to a point

there was, you know, more, you know, was essentially kind of what their brain kind of needed, you know, kind of supported their overall physical health, which then affects, you know, 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, right? And that's very simplistic, but like energy is really critical, energy availability, not too low, not too high. Then the next thing that you need is there 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 are 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 antioxidant polyphenols, things that you get from berries coffee tea chocolate the carotenoids that make things orange yellow and red um lutein zeaxanthin astaxanthin if it comes from seafood that's that's what makes uh shrimp and salmon pink um and then you know some other aspects like dietary fiber seems to have you know some some benefits as well not magnesium so magnesium is absolutely absolutely in there in there too um and in general i think um and that so magnesium uh zinc um then there's some of the structural lipid components things like choline and ethanolamine that you might get from um nuts and seeds or eggs they have some slightly less like less evidence we're really when you're looking at um brain changes over time and dementia risk but those certainly do seem to be related to cognitive function. So there are some studies that show that those who have lower magnesium intakes 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 the short and long term, and they have to do with interactions between nutrients, which, at least to my understanding, are rarely explored. You know, 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, you know, that can potentially impact the same pathways. So there's synergy, there's also, you know, necessity, so that could impact results. The other piece is on what timescale are these nutrients needed and on what timescale are they metabolized? So maybe to just kind of drill into the second question first. So, you know, I'm not out here as like a defender of supplements, but I've been taking supplements in various forms and eating whole foods and eating as generally healthily, you know, 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 etc 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 you know 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 not enough calories not too many mostly whole foods etc 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 i believe that the data are pretty compelling they can be helpful for health maybe even rain 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, you know, 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. I actually wrote a paper on this with colleague of mine rory heath a few years ago the long chain omega-3s that we have in our in our fat stores um 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 um especially in a state of caloric excess um that's going to be stored in your fat tissue and then when you're sleeping or when you initiate uh lipolysis the breakdown of fat so particularly during periods like you're doing exercise those then get released and they you know the brain then has access to them so there's some studies that um show that when you but this relates to the form of the omega-3s as well so many people will tell you that you have to take omega-3s in the phospholipid form uh which is like a special it's a special supplement um you can get it from krill um and the the form is with 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 krill or it's fish oil 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 know most of this 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 omega-3 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 omega-3s 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 omega-3s for a long period of time. They measured omega-3 levels in the CSF, right, in the spinal fluid of these people to show that the omega-3s 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, omega-3s 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, the people in the trial just didn't seem that omega-3 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 omega-3 levels, test your homocysteine levels, which is as a marker of b vitamin status which we know is a a risk factor for cognitive decline dementia as well so if um if you can test your levels and it shows that you need more and yes there are the the normal ranges that you have on a blood test are not necessarily the same as the risk ranges so um homocysteine is a good example a normal range for homocysteine which goes up if you need uh 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 it's 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 cognitive function or slowed cognitive decline. That is particularly the case for omega-3s and B vitamins that lower homocysteine. And so this is the interactions that you were 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-3s or have given B vitamins to lower homocysteine and just haven't seen much of an effect. And everybody goes, oh, well, they don't work. But there are now at least three randomized controlled trials that have shown that omega-3 status and b-vitamin status interact and they're dependent on one another so if you give b-vitamins to somebody who has elevated homocysteine you bring down their homocysteine but they have poor omega-3 levels you don't see any benefit and that's been shown in two trials it was originally shown in the vitacog trial that was run out of the university of oxford um it was then uh replicated in the b-proof uh trial then the other side has also been shown there was a in the omega ad trial they show

that supplementing with omega-3s didn't result in any benefit if people had elevated homocysteine. So that's just one example. And you can imagine, like you kind of said, there are probably lots of these. And if we're not 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 the study doesn't show anything. potentially the one recent um example of kind of just giving a broad based kind of set of nutrients so with a multivitamin that seemed to work fairly well was the cosmos study people may have heard of it was thousands of people of older adults um and they were given either a multivitamin or a flavonoid supplement like a centrum type vitamin yeah it was 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 milk got the multivitamin saw you know changes in cognitive function that suggested some like some some improvements and but that was literally just covering the bases 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 cocoflavanol was only beneficial in those who tended to have a poor quality diet to start with, right? So they just weren't getting many of these kinds of compounds for their diet. If you're drinking a lot of coffee, eating a lot of berries, seeing a lot of fruits and vegetables, you probably don't need it because you're already getting it.

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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 at upper range, upper reference range. And this is something that 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 prehistoric times with 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. Okay, trans fat's bad. Fried food's bad. Eating too much, bad, right? Energy toxicity, bad. Too much alcohol, bad. Zero is better than any, but you could probably drink a little bit and be fine. OK, if you're going to 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 that 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 eat 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 i you know 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 at the population level what's really important is kind of raising the floor like what is going to work for everybody and get most of us most of the way there so like that really is improving food quality um and then you know access to those foods as well right because that's different you know that can be very inequitable like can people afford it do they know how to cook it can you know 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 it you know if i put so if i if i test my omega-3 and your omega-3 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 i genuinely i genuinely don't know like some of these more complex um 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, you know, 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 anabolic 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's 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 kind 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 bro science guys, like the gym bros. It's women who, look, I have female family members, right? um who have and they'll tell me and 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 uh um 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 approved like people are doing it like crazy even I don't know.

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, the whatever, the food quadrants, 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 lean and have great posture into your 60s, 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 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 just 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, you know, cost of living, that's a lot. So I think people do want something that gives them more energy, gives them better sleep, you know, picks up their mood, you know, and I don't think there's anything wrong with thinking about those things as long as it feeds back to to better behaviors particularly when i

think about this kind of this new part of the of the supplement industry and like you said the the you know peptides are just the next the next iteration of the pills and potions and

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 roid rages of peptides? Where are all the, like, I think you can see way more plastic surgery like, whoa, that looks bad, kind of things. Okay, melanotans is 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 it could be a pill or whatever, right? some peptides come as pills i would want some reasonably good evidence of efficacy that this is going to work in humans like me um that's probably not a bar that most of these things

are going to hit anytime soon no people don't care i mean people who 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 low dose should i be microdosing terzepatide or retitutide i'm like retitutide is not even released yet they're like where can i get it are you kidding me you know but it's like it's incredible what's happened in the last few years so we think about

what might what you might think about if you're going to start to consider one of these first of all i would want to see evidence that that it works the majority of peptides don't have good quality evidence in humans except the glp ones right there on the market and the growth

hormone secretagogues but for reasons other than people are taking yeah yeah sarcopenia um you know

other and and with with the most of those uh growth hormone secretagogues come with a risk of insulin resistance diabetes at high particularly at higher doses they're not the super popular ones

I think the super popular ones are, besides the GLPs and reddit trutide as a GLP and other things, but I would say microdosing of reddit trutide and trisepatide, one category for weight loss, fat loss. I would say BPC-157, people are taking it without even knowing what the desired effect is. Recovery is 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 for 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 want it 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?

um but beyond that a question that you have to ask and and i like i like this reframing i heard it recently i heard it recently from um jeffrey bland um which is that if you're going to consider injecting or taking something the first thing you should want to know is 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 and but we don't even have that for most of these

No, we just have the absence of documented adverse effects 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 it may or may not do this thing. But you should also have a specific problem that you're trying to solve. Otherwise, why would you bother taking it? But it's also the case for the vast majority of supplements that are out there and have been around for long periods 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. For some, we do.

Like creatine, omega-3s, magnesium.

And creatine is actually the best. So, like, omega-3s, we know that they're a critical nutrient. Creatine, I think, is the best example because we know it's very safe, right? So even though there's this idea of creatine responders and non-responders, you know, maybe it's going to be useful to improve or support cognition for some people and not others, may improve physical performance for some people and 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.

interesting times again i go back to i love the idea of blood testing tailor 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 um 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 um with sleep tracking people can see, are they getting more REM? 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 L-tyrosine 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, norepinephrine 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 a 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 um 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 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 test what are you asking them like you how good do you feel today yeah i'm one to ten some some

version i feel like i can conquer the world one i feel like exactly on you know and you you can

boil it down or i mean you can um spread it out to many more questions so there's there's a questionnaire called the rest cue 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 feel how good do you feel if you feel good you're more likely to perform well and that works better than the vast majority of data that you like biological physiological data you can collect there are papers that come out on this every year that essentially show the same thing that's kind

of cool yeah because mindset as my colleague ali crumb 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 i'm

Thank you.

You know, maybe sleep scores are like, they mean something, but today, you know, right? I mean, and it can work, right? I mean, in terms of performance.

Yeah. And so absolutely right. Then that gets into like the nocebo 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 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 see they seem to dissociate how we feel versus how we perform right so there are there are studies that show that um uh 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 n back tasks so like very complex uh 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. So there was a paper that came out in science a couple of years ago, giving people 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 no it's

like the the inverse of the cannabis thing where people think they've 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 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 um i say this is that when we're talking about supplements all these other things we're 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 we know very well that some period of exercise can be resistance training aerobic exercise very brief sprints increase arousal improve cognitive function across multiple domains improve learning and retrieval right so you see you're definitely augmenting some of these processes of neuroplasticity some of that's going to be related to the catecholamines and other things that get released as you know 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 um and exerting effort definitely increases arousal um definitely improves cognitive function improves learning as long as it's not truly exhaustive exercise like Like anybody who's done some terrible CrossFit wad or, you know, I used to be a rower. We used to do a 2K test on the rowing machine, right? You do a 2K test on the rowing 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. Thank you for pointing that out because I think that people assume they have an infinite amount of energy and there's crossover. And, um, I certainly have done, you know, extra sets to failure and a great morning workout. And then the, 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 that I do low, low volume, high intensity, you know, usually two sets per exercise to, you know, two or three exercise per muscle, like quadriceps being one muscle or something like that. If I do three, it'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 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 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 dozing off, attention drifting, especially in the age of phones and iPads and things like that.

very difficult um yeah thank you for for mentioning that because they're just an extreme case of the rest of us you know we're told and we're all very busy like oh you need to exercise it'll help your brain and people like why exercise and i'm exhausted you know that's not helping my brain let's get practical here so is there any way uh to it's got to be really subjective and uh depend day to day is 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 as with everything so if you're you know you want to do some you've got some you know learning to do you've got an exam you want to do some hard cognitive work at you know whatever it is writing a presentation analyzing data you're reading you're reading papers writing your 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 we i think that when you look at meta-analyses of exercise and then cognitive function immediately afterwards the 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 um level of activity that the really seems to 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 that the amount of catecholamines released from again catecholamines folks being the you know adrenaline norepinephrine and uh dopamine um generally increased levels arousal alertness propensity to move you just that's that i feel better people often think about the runner's high and endorphins the endorphins come from pretty long intense duration effort they're more of a you're floating kind of like you know i think the catecholamines are really the 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 a 30 minute jog i don't expect

you'd get that much catecholamine release i mean you'll definitely get some right and like cortisol too right which obviously increases alertness and arousal and can can in the short term make you feel good it's a good thing yeah um you you see similar effects of you know short resistance training workouts um 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 some it's something in that in that sphere and i think it's that's probably just it it's just enough to you just kind of boost catecholomies a little bit a little bit of cortisol 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 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, well, 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 um the the best example um is with aerobic exercise on the kind of uh 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 brisk walking three times a week 40 minutes um and when you kind of read the study and and the heart rate uh 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 uh 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 probably 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 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 very similar similar to that previous study that i mentioned and the third group did a high intensity interval training intervention which was the norwegian four by four protocol so four minutes uh 85 to 95 percent 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 you then say well hey do that three times a week for six months like 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 and they maintained that benefit for five years after the six-month intervention so they worked really hard um 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 um and the more cortisol 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 oh don't do high intensity exercise it releases cortisol that's stressful 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 um 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 uh what was the form of exercise was it rowing or biking it was on a treadmill treadmill yeah uh really interesting um and you said at about 85 percent 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 releases a whole bunch of myokines and lactate in particular. We know that lactate very easily gets into the brain, stimulates BDNF production as kind of part of that support of neuroplasticity 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

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to be sustainable for long periods of time, like I would typically say one day of high intensity work is fine, right? Because you probably, you 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 kind of moderate, kind of maybe more like zone three, four. Um, so thank you for putting in a strong, um, word for cortisol, not always being the bad guy. Um, people are so afraid of cortisol. You want your morning cortisol high. It's going to make you sleep better at night, more energy during the day. It's, it was interesting to me to dive into the literature on cortisol and find that a moderate and 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 and like or 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 or it's kind of wild how afraid of cortisol people are people think they're going to get cushing syndrome it's been i don't know what the psyop on cortisol was all about but you know you're you get moon face. You won't be able to lose abdominal fat. I mean, there is a real condition, which is you and I know it's a Cushing syndrome where cortisol is, is pathologically elevated, but come on folks, like cortisol goes up, cortisol goes down. You have that, but 20, 30 fold from the morning until night in a healthy individual. So what do you think it is that, that people get, you know, 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? What did our predecessors do wrong? You know, let's blame it on the parents because we weren't doing science communication. What in the world was the incentive for like

demonizing molecules? It's so crazy. So even though his frameworks are still potentially very helpful, some of it we can blame on Hans Selye and his like general adaptation response, Like the original idea that if you were chronically stressed, it would lead to like 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, increased allostatic load, increased metabolic disease, inflammation, blood sugar dysregulation, insulin resistance, significantly associated with heart disease, dementia, all these kinds of things, right? so we so we know that these chronic stresses are can be really detrimental to our health but we've kind of conflated that like 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 cellier originally described it is stress drives adaptation he called it general adaptation syndrome or 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 like look me and measure their cortisol levels after a workout it actually looks very similar to how it would look if you just broke on your arm or if you're 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 neuroplasticity that requires adaptation and so some of that core stress response is involved in that, the release of catecholamins 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 evidence for the cross-stressor adaptation, particularly with exercise, right? So if you exercise regularly, you are better at dealing with other stressors like psychological stressors. You're more robust to stressors. 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've kind of, you know, 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 Sally also talked about the idea of hypostress, right? Not having enough stress because then you can't, you don't adapt, you don't build function and response. So we just need to think about them very differently

because those acute stresses are incredibly important for driving adaptation.

Well, yeah, I think of it as pick your stressor. 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 i don't want to say there's no limit to the amount

of stress they can absorb but when it starts to erode your sleep that's perhaps when things need to be you know adjusted yeah resistance training um 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 of action so there's that that acute kind of arousal and this would be um you know you you go in the gym you do a couple of sets you're not maxing out um you know it's it's probably going to be a fairly typical couple of sets of uh 8 to 12 reps kind of. 80 percent of of max something like that you do compound movement so most studies use machines right um so maybe do a leg press and a chest press and a lap pull down okay multi-joint 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 some acute bumps in in cognitive function probably through through arousal the mild activation of those arousal pathways actually quite similarly though i mean probably um slightly higher intensity will also be beneficial as long as you're able to recover over time like that that that recovery is critical just like i was just saying in terms of any kind of adaptation um there are 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. Very similar. So there's multi-joint machines in the gym that anybody can do. And they're in any gym. Presses, pull-ups, rowing, pull-downs, leg press, hamstring curls.

Exactly.

Okay. Yeah. And what you tend to see is that if you do that for at least six months, So the studies go on 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.

Do you want to remind people what white matter is just for the newbies?

Very broadly, you have white matter and gray matter in your brain. In the human brain, white matter makes up approximately 60% more than most other species, any other species. and so like 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 myelin sheaths on your axons that's what allows those nerves to conduct information really quickly whereas aerobic exercise on that kind of intensity spectrum we 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, amyloid, 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 function. So aerobic exercise is gray matter and memory and resistance training is white matter and more sort of executive type decision-making, processing speed type functions. You know, we talked about lactate and some of these other things that might increase BDNF with the aerobic training. in resistance training the i think the primary mediator of that or one of them is igf-1 which is particularly increased with resistance training we know that igf-1 is really critical to the development of white matter uh you know right you know in the womb and then as a baby and it seems to be also really important for white matter structure then throughout um the lifespan so resistance training is a really great way to then create these boosts of igf-1 so that's probably but 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, IGF-1, BDNF, lactate, and on and on. Just for, how do you say in Britain? Well, it's not kicks, they use a different word, but for kicks and giggles, I'll just tell you, there was 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 the 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 that increase REM sleep, very, very few, except sleep deprivation and then REM rebound. Likewise, there was a review published by a guy named Jeff Lichtman 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 where they 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 it's, um, 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, small or 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 long-term potential. 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, uh, 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, three years ago, I would have said, all right are we really talking about exercise opening plasticity this 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 but it turns out to not be that meaningful yeah in terms of new neuron production isn't that doesn't seem to be that meaningful for human uh memory and offsetting cognitive decline so 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 etc 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 of single molecule manipulations. I think they're very important in a certain context, but for a while it was like, gosh, everything opens plasticity and everything disrupts around sleep. 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 you know we don't really do much until dementia is diagnosed it's but it's very similar like we don't do very much until diabetes is diagnosed you know ideally we can we can act much earlier in that trajectory and that's increasingly being accepted in the neuroscience and neurology communities that actually we could potentially change that trajectory or at least decrease risk and so within dementia there are as 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 of daily 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 Lewy bodies, frontotemporal dementia, and then dementia related to Parkinson's, potentially, although that overlaps a lot with Lewy body dementia. And dementia in Parkinson's may just be, may actually mostly be Lewy body dementia. But we've gotten to a point now where it's generally accepted that potentially half of cases of dementia are preventable. And I think the majority of that falls into those first two buckets, 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 dementias as well when you then think about alzheimer's disease specifically there's there's one small slice of alzheimer's which is like monogenic dominant mutations that you have in either where most of them happen either in the presenilin genes presenilin one and two or the amyloid precursor protein gene they make up at this point less than five percent maybe as little as one percent of alzheimer's disease so we kind of we set those to the side a little bit the vast majority of alzheimer's disease is what we would call late onset alzheimer's disease, although it's happening actually early and earlier in some populations. Yes, there's a genetic component. Your ApoE gene is probably your most common risk gene. There's also polygenic risk, so thousands of genes can give you a little bit more, a little bit less risk of Alzheimer's disease. But it's much more related to lifestyle and the environment than, say, that kind of early onset monogenic alzheimer's disease and the the kind of the best accepted um review of all of this um is run by the lancet commission commission on dementia prevention uh overseen by professor jill livingston and their most the most recent version of this suggested there were 14 risk factors who between them accounted for about 45 of uh dementia risk or dementia cases and that that are modifiable so early life education high blood pressure diabetes hearing loss vision loss brain trauma um high uh high cholesterol they recently recently added high ldl high ldl cholesterol low physical activity so this is all related to the things we've already talked about right maintaining good physical health maintaining uh maintaining inputs getting inputs in the first place right education is is uh is critical and hearing loss as i recall was an important one

in reference to inputs like you don't want sensory input degraded absolutely so hearing loss vision

loss um social isolation um they didn't uh there's quite so two things they didn't include um that were fairly controversial and were sort of debated letters were written to the editor and all that kind of stuff as happens in in academia uh related to so they didn't include sleep loss or sleep deprivation as a risk factor for dementia even though the evidence particularly if you 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. Very 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-OK, 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. LDL goes up, stress levels goes up, diabetes 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. Part of it is related to how they analyze the data. So we can get to that but i mean 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 that kind of about right yeah that sounds about right because it's

the i think it's a lot it's the lack of those last two cycles where that are rem enriched yeah you know because in the beginning of the night you get your growth hormone surge you get a lot of deep sleep assuming you're you know doing things right during the day and and then it's those last you you know, two 90 minute-ish cycles that you glean most of your REM. And if you're not getting those night in and night out and night in and night out, like 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-3s, B vitamins, which we do actually have some quite high quality interventional and observational kind of epidemiological data for. So there was kind of some discussion as well as those things should have been included. other analyses that looked at those suggested that they potentially contribute a significant amount of the population attributable 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 maybe as many as or as much as 70% of dementias may be preventable. But then you have to start including things related to socioeconomic status and deprivation and other societal factors that we know have a massive impact as well. So that's less modifiable, like on the individual level, right? It really would require changes at the societal level, which is kind of harder to do. Can 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 how 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 if you want to say that um the shingles vaccine decreases 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 the studies that have happened so far uh there was one in the uk in in wales uh 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 Zostavax, which was a live attenuated vaccine. There's now a newer version called Shingrix, which is a recombinant vaccine. And there was a study done in the US that compared people who switched from, you know, there was a similar switch from Zostavax to Shingrix 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 um or studies because 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-meyer curve so it's like a survival curve so like um 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 you know got the vaccine or not they diverge very early which kind of says that oh it only takes a couple of months to kind of see this difference in dementia risk which you which you wouldn't really expect based on like the natural course of dementia takes years to happen so um this is very common in these kinds of studies um and it's 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 going to get less dementia anyway and so maybe the shingles 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 um there's a signal there there should be a randomized control trial that's that's happening but there's a number of reasons why this might be the case one uh it obviously we know it reduces cases of shingles shingles can be very painful it can you know can uh change how people interact with the world you stay at home you don't feel good you're in a lot of pain for a long period of time that can be that can go for many months it's rare for it to last many months but it can can last a long time um then you know there's 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 uh in cases of shingles right there had to be something else going on as well they've suggested that it may be um due to like an immunomodulatory effect it may be because you're also suppressing other viruses like herpes simplex virus that we know uh may also be associated with uh certain cases of dementia or alzheimer's um and the reason you know 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 is in men um and it may be that that sort of um meaning it's more effective more effective in

women than it was in men and we should mention that the shingles 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, we'll 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 in particular cell types. 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. 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 eight seventies and eighties oh wow yeah okay so again um it would be very fair to argue that getting it much earlier we don't have any evidence for because you know in reality and in these particularly in these the studies um like the uk this is done in the national healthcare system it was you know for the the highest risk older older adults and so getting it in your like 50s or you know mid 50s which is um sort of the guidelines in the us that yes to reduce shingles absolutely but it doesn't map onto the dementia risk um age that was seen in 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 study done at the University of Washington in Seattle primarily. 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 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 of 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 that step change down was even bigger so you could talk about you know how people maybe could have changed things in order to recover some of that function afterwards i think that would have been possible if we you know thought about how you might intervene but a major i think it's a 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 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 you're older, which we've seen as a result of 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 bleeds and things like that. So I'm talking about moderate concussion. Someone got their, quote unquote, bell rung. They slipped and fell. They got clipped in soccer practice. their kids a little dizzy now of course somebody young or old is vomiting or you know 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 kind of get over mild concussion or moderate concussion the evidence based on this is a little shaky but i

I think for most things, it kind of fits into this idea of positive asymmetry, right? Low risk, high potential for benefit. And there have been lots of, you know, there have been randomized control trials to kind of look at some of these things. So a couple of years ago, we published a paper looking at different nutritional supplements after concussion that, you know, we have some reasonably good evidence for. So, yes, you should be seen by a doctor. You should get whatever scans and, you know, immediate medical care that you need. Absolutely, right? that's we're assuming all of that is done or will be done yeah Immediately, there are a couple of things that I think we know from sort of animal studies that translate fairly well onto humans, but also 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. Hyperthermia. Hypothermia. Yeah, 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 to say. Brain doesn't like to get too hot. That's 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 hyperthermia. 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 stressed environment. You're on a football pitch. It's August in Alabama. It'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 thermoregulation will be really important. the next is uh blood sugar regulation so we know that after a significant brain injury you have increases in in blood sugar that's associated with worse outcomes some of it's like what's caused what's consequences the injury driving the blood sugar is the blood sugar driving the 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 want of a better word right about alcohol so alcohol um i would avoid as well mainly because it impairs sleep and we know that 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 um one thing that with the reason why hyperthermia or getting too hot makes the injury worse is because it um 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 mitochondrial failure or mitochondrial dysfunction. And so if you get too hot or you stimulate the brain, you're asking for more

energy 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 and some of these other processes that then may happen. So avoid alcohol, avoid caffeine, both of those potentially related to improving sleep then uh things that we have some you know reasonable evidence for um immediately after concussion are creatine at what dosage the best trial was actually done um in a like pediatric group although very broad it was like one year old to 18 years old um but they gave 0.4 grams per kilo per day so whoa yeah so it's it's a pretty it's like double a traditional or loading dose if you're a 100 kilo person. But like 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.

A few extra trips to the bathroom could 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 meta-analyses show that you actually don't get, it's actually quite rare to get more GI side effects with creatine compared to placebo. though. Some of it is probably related to the quality of the supplement. So poor quality creatine supplements have more adulterants that may cause some of those GI side effects. Some of it can be due to high, you can saturate the creatine transporters. It doesn't get absorbed. Water gets drawn into the gut that can then 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 non uh head 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 um augment the 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 ounce or two 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 it's 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 creating 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. If anybody's just taking creatine for other reasons, this is a standard dosing protocol. I think it's fine.

I thought you were going to tell me I could get it to work that way.

so so like the 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 for a week and then you see significant increases in brain creatine but the creatine having other effects on the brain you know potentially improving mood improving memory and in older adults um some of those benefits happen at just like a traditional creatine doses so you don't need to take massive doses you know think 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 shown what form those studies actually use magnesium oxide surprisingly um but i would probably use magnesium glycinate um the it's very bioavailable um athletes usually need a bit more glycine anyway but any bioavailable form will be fine then omega-3 fatty acids um The evidence is a little bit better for, like, there are now several studies in, like, 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 light, that are circulating in the blood. So that's something that I would just take long, like, long attunely. if you're somebody who's at risk of a concussion because of your sport or your job i would just you know take a reasonable omega-3 supplement just long term because we have some reasonable evidence for that then other things might become a little bit specific to the symptoms that you're experiencing so if you have sleep issues then there's studies that have used melatonin and that's that's shown improvements are branched-chain amino acids at high doses for sleep and that's interesting because outside of tbi high doses of branched chain amino acids may actually impair sleep because they compete for tryptophan 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 branched chain amino acids if somebody's going to take branched chain amino

acids presumably they're going to look at how much leucine is there for a variety of reasons So do you recall how much leucine to get this effect post-TBI?

So I don't think they, at least I don't remember the leucine dose, but they were taking up to 60 grams of branched-chain mouse. 6-0. 6-0.

Okay, because a typical kind of suggested supplement bottle gym dose would be 3 to 5 grams. That's usually about 6 capsules. Yeah. So, okay.

So like one study they did in veterans, They had, I think it was three doses of 20 grams spread across the day.

Are you curious about these Ibogaine studies that are looking at, you know, TBI and brain recovery? I mean, Ibogaine is 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 like macro doses, right? in the psychedelic doses. I think that there's a lot more to come there, but certainly the trials that have been done so far are quite compelling. But that's obviously in a very controlled kind of clinical setting.

Yeah, you have to be heart rate monitored. Again, it's not legal in the United States, although things are shifting.

But choline is another thing, particularly as citicholine. So best evidence is for one to two grams a day. Of choline. Of choline. In the form of CDP-choline or citicholine, which is the same thing. um those are the main ones then there's some other like uh niche supplements that do have some evidence the one that's probably has the most evidence for it is boswellia boswellia uh yeah uh which is a frank indian frankincense uh but there's an extract of boswellia that's been tested in i think three different clinical trials after tbi showed some benefit and zogenol which i think is a pine extract slightly less evidence than boswellia i typically would recommend people stick to the first group of kind of nutritional type supplements um but in very specific um use cases based on specific symptoms some of those other things might be beneficial then beyond that we know that physical return to physical activity as soon as possible is really important without getting another head injury without getting another head injury and you know so so this really changed over the last few years you know maybe five ten years ago people like you know rest is what you need to do go lie in a dark room if you've got a concussion in sports you 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 uh two or three times a week at a level just below what might make your symptoms worse and then first you do sort of like non-specific aerobic exercise and then you start to bring back skill specific exercises sports exercises then go back into full training and then um go back into into playing kind of in that order and that should be quite systematized now so i would expect sports teams to kind of have that in place so like the standard of care is generally physical physical therapy if you have any ongoing cognitive or physical symptoms sort of a month plus after any kind of traumatic brain injury um there's some evidence that like virtual reality or augmented reality physical activity might improve cognitive symptoms vestibular therapy for balance and dizziness issues and then increasingly you know there's a focus on sort of oculomotor training for like convergence or other eye like eye issues that are very common after concussions but aren't picked up as often as people might like but increasingly kind of eye tracking and these kinds of things are done particularly in professional sports or other arenas after brain injuries to kind of ideally you'd have a baseline you figure out what's changed and then you would track that over time and you can 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 the you know all the latest and greatest uh you know technology and coaches and nurses and doctors that um you know there's a lot of head hits out there that aren't you know fortunately aren't um full-blown brain bleeds and brain damage but the um 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 strongman competition uh-huh all natural this is not the enhanced games no um just tell us what the format of that is well first of all how How old are you? 41. Cool. Have you done one of these before?

Yeah, I have six or seven competitions at this point. I started during COVID. I've done like a competition or two every year since then.

You're a tall guy. You're like 6'2". You weigh... Like 210, 215 usually. And is it... So it's height and weight class or just weight class?

So it's weight class. So now that I'm older than 40, I compete in the master's category. So there's one of my favorite things about Strongman is that if you weigh less than 200 pounds, you're a lightweight. so i'm uh i'm in the lightweight masters category it means that i usually have to like do a water cut to like for a weigh-in because i don't normally i'm not i'm normally above 200 pounds um but yeah they so they have they have weight they have weight classes and

age classes can you eat your way and hydrate your way back up to after yeah like the usually way in

20 hours 24 hours before i'm i'm definitely back to my usual weight by the by the next day gotcha

yeah, we don't want you trying to lift heavy things, dehydrated. What are the big events? So you're carrying stuff overhead, you're carrying stuff at your sides, what are you doing?

A standard kind of local regional competition is five events. I qualified for the natural, like, world's 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, like, carrying something, lifting stones, farmer's walks. So in a truck pull, something like that, so like more dynamic. So there's like usually like a static max strength thing, but then also like more dynamic.

With the teeth? Yeah. You do the teeth pull?

Oh, no teeth, no teeth pulling. Cool. 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 like pick things up at the side and kind of.

And so for a guy, let's say you hydrate back to like 205, 210 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 that's 264 pounds per hand. And as far as you can carry it, I can't remember if it's…

That's a big human in each hand.

Yeah. So typically, you know, if you can get to where you've got like 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 um but like you know some people might say half your body weight in reality if you pick something up heavy and move with it that's great like and then get better

recommendations this is your

time to shine my friend people can work their way up i i watch uh tom haviland's oh yeah uh instagram we'll put a link to it everyone should see that his wife and his kid also uh work into the workouts he's got a but man he's strong but yeah carrying heavy weight no no this is not your time to tell people how to tiptoe into that's a different podcast so you're carrying 220 pounds in each hand 264 pounds per hand and walking how far it's maximum distance um in i can't remember

If it's 60 or 90 seconds. You can't set it down. You can set it down. Okay. So as far as you can get in that period of time. And then be similar with a yoke walk. So there's a yoke where, you know, sort of like put it on your back. It's 700 pounds. How far can you walk in that period of time?

Love this. So primitive. Love it. Pure hypothalamic event. Yeah.

So in that event, in the yoke walk, if you get to the end, I think it's 30 meters, 90-ish feet. If you can carry that that far in the time cap, then you do reps on a circus dumbbell. so like this big massive dumbbell that you have to like shoulder 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 uh like over over a platform that's like i think 200 to 300 pound implements they kind of increase over time um there's a maximum squat and you have a choice of two different um weights um and so like if you choose the bigger weight and you get reps on the bigger weight that you get a better score than somebody who did back squat it's a standard back squat it's with an axle bar it's like a thick bar um and then in strongman when you have squatting you usually have pads that you squat down to so it's a specific height you squat down to um so like that could give you an advantage if you're shorter right because you have to go less distance to get the weight on the pads

but like there's no geeking it and calling it less than a one rep no no people have done that

it doesn't look good yeah no no like it just has to hit the pads and come back up yeah and the weights are 170 kilos and 200 kilos so that's what uh nearly 400 pounds and 440 pounds uh log press um for reps and again it's a similar style and i think it's 100 kilos so 220 pounds and then 120 so 264 and then there's a sled like you uh i think you push a sled and then you load it with a 275 pound sandbag and then you drag it um in a time cap i think that i think that's all the

events awesome uh you'll let us know when it is yes uh 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 uh clearly um you got a lot of brains in that uh skull of yours and you you're also super strong. Love hearing it. That's, that's great. And, and, uh, you have no excuse not to carry the groceries at home, right? So you lost that, that, right. But there was no doubt you would anyway. That's awesome. I, I, I'm very impressed by the, by people who continue to take on athletic challenges in their, uh, in their adult life, which is very appropriate to context today. So Dr. Tommy Wood, thanks for coming out today. I learned a ton from you and, you know, going into this i like 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 but i learned a lot from you today and i know everyone else did as well you're an exceptionally clear communicator and um you're working on not just an important issue you're working on the issue uh this neuroplasticity thing and a whole lot more so let's definitely get you back to talk about recovery from brain injury and stroke and things of that sort because there's a lot of additional things i think we could dig into but uh meanwhile You've given us a lot of actionable tools. And yeah, I love that you're doing the strongman competition and come back again. We appreciate you. I will. 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 and or enjoying 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. If you have questions for me or comments about the podcast or guests or topics that you'd like me to consider for the Huberman Lab podcast, please put those in the comment section on YouTube. I do read all the comments. For those of you that haven't heard, I have a new book coming out. It's my very first book. It's entitled Protocols, an Operating Manual for the Human Body. This is a book that I've been working on for more than five years, and that's based on more than 30 years of research and experience. And it covers protocols for everything from sleep to exercise to stress control, protocols related to focus and motivation. And of course, I provide the scientific substantiation for the protocol.

that are included. The book is now available by presale at protocolsbook.com. There you can find links to various vendors. You can pick the one that you like best. Again, the book is called Protocols, an Operating Manual for the Human Body. And if you're not already following me on social media, I am Huberman Lab on all social media platforms. So that's Instagram, X, Threads, Facebook, and LinkedIn. And on all those platforms, I discuss science and science-related tools, some of which overlaps with the content of the Huberman Lab podcast, but much of which is distinct from the information on the Huberman Lab podcast. Again, it's Huberman Lab on all social media platforms. And if you haven't already subscribed to our Neural Network newsletter, the Neural Network newsletter is a zero cost monthly newsletter that includes podcast summaries, as well as what we call protocols in the form of one to three page PDFs that cover everything from how to optimize your sleep, how to optimize dopamine, deliberate cold exposure. We have a foundational fitness protocol that covers cardiovascular training and resistance training. All of that is available completely zero cost. You simply go to Hubermanlab.com, go to the menu tab in the top right corner, scroll down to newsletter and enter your email. And I should emphasize that we do not share your email with anybody. Thank you once again for joining me for today's discussion with Dr. Tommy Wood. And last, but certainly not least, thank you for your interest in science.