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Written by The Thriva Editorial Team
10th Sep 2026 • 53 minute read

Dr Tommy Wood joins Greg and Charlie to explain why cognitive decline isn't inevitable, and why doing things you're bad at might be the most powerful thing you can do for your brain.

Show notes

Most of us assume cognitive decline is an inevitable part of getting older. But what if the science says otherwise? Dr Tommy Wood says this is a modern health myth. His argument: if stimulated in the right way, the adult brain can stay sharp and high-functioning well into retirement age.

A neuroscientist, performance consultant and recent author of The Stimulated Mind, Tommy has spent his career applying the principles of brain performance to a wide range of lifestyles, from Formula 1 drivers to busy professionals. This week, he sits down with Charlie and Greg to explore what it actually takes to keep your brain healthy and adaptable across time.

Starting with the science, Tommy walks us through how the brain develops, and why being challenged through learning is good for neuroplasticity. He helps us wrap our heads around this with a helpful shorthand he calls the 3-S Model: stimulus, supply and support. Our guest also makes a case for freeing up "headroom", and we'll let you find out what that means. Together, we explore why cognitive decline is so often the result of a more sedentary lifestyle, and how to circumvent that.

In the practice segment, Tommy, Greg and Charlie get into tangible exercises and small habits we can all try to improve our brain's ability to learn. Including:

  • Why video games are actually good for us (32:30)
  • Which types of physical activity sustain brain health best (36:18)
  • The case for learning a language, and yes, this includes coding (39:32)
  • How to stay challenged in a world where AI starts doing the thinking for us (42:18)

Finally, in the experience section, we turn to real-life learning challenges and answer your listener questions. We've got a fascinating discussion on access to information in the age of the internet, and how that impacts our memory capacity. We also bring you practical answers to reconcile the enjoyment of learning new things with long-term cognitive benefits.

Enjoy the conversation. If you'd like to send us your health questions for future episodes, email us a voice note or write in at themethod@thriva.co.

Mentioned in today's episode

Transcript

Greg: The first time I downloaded Duolingo was before going to Ecuador in 2014. And the only thing I remember from that was "I am not a penguin".

Charlie: A useful thing to be able to say.

Greg: I was using it on a daily basis.

Charlie: Donde está la biblioteca, por favor. Where is my pencil sharpener? I think that is...

Greg: The pen.

Charlie: Sacapuntas is that pencil sharpener?

Greg: I don't actually know what a sacapuntas is.

Charlie: I think that might be pencil sharpener.

Greg: It sounds better in a northern accent. Sacapuntas.

Charlie: This is The Method, a podcast from Thriva about what health looks like in the real world.

Greg: I'm Dr Greg Potter. I'm a scientist and health and performance consultant.

Charlie: And I'm Charlie Edmondson. While Greg's the sports scientist, I'm definitely not a science expert. I've got a regular job and I'm here to remind Greg of what life's actually like when you're not a nerd.

Greg: Be a nerd about something. I bet you are.

Charlie: On this show, we work out some sustainable changes to your routine that are actually going to make a difference to your health. To do that, we have a simple three-step method. With the help of an expert, we first unpack the science behind one key health question. Second, we give some recommendations related to what we're speaking about. And finally, we put the practice to the test. Each week, we hear from those who have tried and tested our recommendations to help turn a so-called ideal lifestyle into something that actually works for you.

Today we are talking to Dr Tommy Wood, neuroscientist, medical doctor and associate professor at the University of Washington. His work focuses on brain health across the lifespan, and how things like exercise, nutrition and lifestyle shape how our brains function over time. We're going to look at how to keep your brain healthy, not just now, but long term.

Charlie: Right. What are we talking about today? Oh, we're talking to one of your friends today, aren't we?

Greg: Yeah, the mighty Dr Tommy Wood.

Charlie: How do you know Tommy so well?

Greg: I know Tommy because in 2017 he asked me to be on a podcast he was hosting back then. I was hosting a podcast for Humanos Radio periodically, and I interviewed him for that. We stayed in touch, and since then we've worked on a bunch of projects together, but from different sides of the world.

Charlie: Shock. Very rare you're on the same side of the world as anyone else, Greg.

Greg: Tommy's got a new book out, his first book, The Stimulated Mind. The gist of it is that it's really important to do things you suck at.

Charlie: Oh, what are you bad at, Greg?

Greg: I wouldn't know where to start with that. Just living entails doing things I suck at. Good for my brain. Yeah. That's probably top of the list.

Charlie: What are you bad at though?

Greg: All sorts of things. But it's not so much about what you're bad at, it's more about doing things that challenge you, and in doing so, forcing your brain to remodel itself in ways that help keep it healthy in the long term. I think what a lot of people miss is that learning is relevant to unlearning too. A lot of people want to unlearn things, and it might actually be more important for them to unlearn them.

Charlie: As in bad behaviours?

Greg: Well, as in things that cause problems in their lives. For example, addiction. It's enormously widespread. I don't mean to pathologise it, but a lot of people have a low-level version of that, and it's often something someone is a bit ashamed of. If they can understand how to rewire the brain, then maybe they can do something about that. So while we're focusing on learning, a lot of the concepts are relevant to unlearning too. If there's something you want to unlearn, then that is possible. The onus is on you finding something you enjoy, that you find difficult, that's a productive thing for you to do. There's nothing damaging about it, and applying yourself and doing it on a regular basis will likely be good for your brain. Is there anything that fits that mould for you, Charlie, that you've been doing this year?

Charlie: Well, I did take up bouldering, didn't I? That's been really fun. I downloaded Duolingo last year to work on my Spanish. I've deleted the app. I wasn't... well, pequeño almost fluent. But what I found was I was learning phrases I'm not sure I'm going to use all that much. You know, mi gato es negro, my cat is black.

Greg: What was your streak? What did you get up to?

Charlie: Oh, I think I got a few months in. But then I've deleted all the apps off my phone. I put app limits on all of my social media, because it just feels like a time suck. I don't even really know what I was doing it for. You only realise when you set a time limit on it that makes you go, where has that hour gone?

Greg: Yeah. I just see it in my screen time in total. My screen time when I first bought an iPhone used to be probably an hour and 40 minutes a day, something like that. Now there are days where it'll climb well over four hours, especially if I'm knackered and I'm in transit. It can get so high. I don't want to spend my life that way. I'm not going to look back at my life and think, I'm so happy I spent all that time looking at my smartphone.

Charlie: So what are you learning?

Greg: Well, it's funny you mentioned Duolingo. I've used it on and off for years. I start my day with Duolingo and basically keep going until my battery is low.

Charlie: Oh.

Greg: When I say battery, I mean my Duolingo battery, because you start with 25 points, that's fully charged battery. But I'm learning Indonesian, Spanish and Italian. It gets a bit confusing transitioning between Spanish and Italian, I have to say.

Charlie: Are you going to be a polyglot?

Greg: No.

Charlie: Oh my god.

Greg: Polyglot, it's a great word, isn't it? More like a polyclot. That was always my dad's insult. If you're being a bit thick, it's like, you clot, polyclot. So some language learning. In Indonesia right now I get to speak a little bit of Bahasa Indonesian. But I've also done a bit of freediving this year for the first time.

Charlie: Oh.

Greg: Which I enjoyed. It's quite different. I do a lot of scuba diving and there's some transfer, but you don't get the time underwater watching all of the magic unfold in front of you. It feels a bit more like a survival mission. But you learn a lot about self-control. Interestingly, a lot of the relaxation methods that you use for people who struggle with insomnia, people in the freediving world use. So I think I'll probably continue it.

So yeah, those are the only things that come to mind. I'm sure there are some work-related things I'd like to pick up too. For example, I don't use large language models for anything. I find myself averse to the prospect of using them, but I know I need to get over that hump. I know they can help me produce certain types of work much more rapidly, and they're going to be an integral part of work for everyone in years to come. So I definitely want to do some learning related to those.

Charlie: Well, we can ask Tommy for his thoughts. Shall we bring him in?

Greg: Let's do that.

Greg: Dr Tommy Wood. Welcome to your 400th podcast of the year so far.

Tommy: Thanks. It's nice to celebrate my 400th podcast with you. No, it's maybe my hundredth, but it has been a lot. I'm very happy to be here. Obviously, I like the sound of my own voice, so I can just keep going. Wind me up, set me off. I'll talk for three hours, no problem.

Greg: We like the sound of your voice too. So much that we'd like you to sing, Tommy.

Tommy: No, no. Charlie already found the song.

Charlie: I heard a rumour that you were in a choir, actually. Is that true?

Tommy: A long time ago. Yes, I was in a couple of choirs.

Greg: You wrote about that in your book, and you wrote about the fact that singing is good for your brain, Tommy. So we want to support your long-term brain health.

Charlie: Kylie Minogue, Can't Get You Out of My Head.

Tommy: No. No way.

Greg: Your karaoke song?

Tommy: I don't think I've sung karaoke since I was in secondary school.

Charlie: I've not done karaoke for 48 hours. I was doing it at midnight in France on Monday night.

Tommy: What was your karaoke song?

Charlie: My go-to would be Cher, Believe.

Tommy: Oh wow. Can you do the warbly auto-tune?

Charlie: Can I? I can do it better than Cher. Do you believe in love after love, after love, after love, after love. She's got to keep it going. But it's not really appropriate for the theme of the episode today, is it? I'm not talking about believing. Oh, maybe.

Tommy: I mean, belief is actually a really important part of some of the stuff that I imagine we'll talk about. So it could work.

Charlie: Seamlessly.

Greg: I believe in science. I believe in science.

Charlie: Of course you do, Dr P. Heart science. So, into today's science section. In your book, Tommy, you challenge the myth that we're bound to decline cognitively with age, that we're all on an inevitable downward trajectory. What's the argument you make and what are some examples to back it up?

Tommy: The argument I make is that historically we have kind of embodied this idea, as individuals and as a society, that the function of the human body and the human brain are sort of destined to decline with age. I will say upfront that yes, ageing is still a thing. We cannot prevent it entirely. However, we have traditionally thought, over the last hundred years or so, that once we get to around 60 years old, it's just this catastrophic decline into cognitive impairment and potentially dementia. And maybe even that decline starts much earlier, in our twenties or thirties, and it just continues from there.

When you look at some of the data we have from some large population cohorts, we see that's actually not necessarily the case. One of the best examples of this is now quite old. It was called the Seattle Longitudinal Study. It was done here in Seattle where I work at the University of Washington. It started in the 1950s by a guy called Warner Schaie. It was one of the first studies to look at the same people over time, bring them back every few years, measure their cognitive function and look at factors that affected their cognitive function over time.

What they found was that from people's late fifties into their eighties, the majority, more than 50% of people, maintained the same level of cognitive function or even saw some improvements from their fifties into their eighties. So the norm we could expect is that we maintain function.

Yes, some people do lose function, and we have some idea of the lifestyle and environmental factors that drive a lot of that. Some of the original work done in this study showed that. But in reality, the majority of people could expect to maintain function into their eighties.

Those data were actually used to raise the retirement age in the US from 60 to above 65, because it was the first time we saw that people could maintain function very late into life. But the rest of us haven't really realised that, because when you talk to people about how they expect their brains to function over time, they still think they will lose function and there's nothing they can do about it, even though we have data going back 50-plus years to suggest that doesn't have to be the case.

Greg: It could be that the retirement age just continues to drift over time. If that ultimately sustains your brain health a bit longer, then the retirement age could keep getting pushed to the right.

Tommy: Not everybody would be happy about that. You can get those inputs and stimuli elsewhere. It doesn't have to come through your work. But it's just a reminder that remaining cognitively engaged is a really important part of maintaining function over time.

Charlie: You speak a lot about the importance of doing things you're not good at to build and maintain what you call headroom. For those who aren't aware, could you just explain what is headroom, and why is it good for a person's brain to do things they're not so good at?

Tommy: This is actually like seven questions in one. So please do interrupt me if I keep gathering on. The idea I've taken from an economist and former professional baseball player, Art De Vany, who was writing about physiological headroom decades ago. It's this idea that your headroom is the difference between the function you need on a day-to-day basis compared to what you are maximally capable of.

The strength of your legs you need on a day-to-day basis is like the strength to walk up stairs, or get out of a chair, or get off the toilet. But your headroom for your leg strength would be the difference between the strength it takes to get up out of a chair versus your maximum squat or leg press in the gym. That's your headroom. What's the difference between your baseline versus what you're truly capable of?

Charlie: Mm.

Tommy: We can think about a similar buffer for the brain. So it's the difference between what you need to just get around, remember things, remember people, versus what your brain is really capable of when you're deep in a complex skill or task, or something you're an expert in. The goal is to have as big a difference there as possible.

There are components of headroom that roll in some very formal concepts from neuroscience people might have heard of. The first is reserve. That's cognitive reserve or brain reserve, which are two related things. Brain reserve is essentially how much brain do you have inside your skull. Usually more brain is better, because you lose brain with cognitive decline and increased risk of dementia. We call this brain atrophy over time. So you want to maintain as much brain as possible. Something that contributes to brain reserve is energy and nutrient status. If you're low in certain nutrients, you tend to have lower brain reserve. If you are low in total calories, not getting enough energy, you have lower brain reserve.

Then the next thing is cognitive reserve. If brain reserve is your hardware, cognitive reserve is your software. Cognitive reserve is how much redundancy do you have in the system. Something really important for cognitive reserve is cognitive challenge, cognitive stimulus, educational status, hobbies, skills. Those kinds of things help build redundancy in the system. It makes your brain more efficient, gives you more capacity to do more complex tasks at once.

The next component of headroom is resilience. In neuroscience, cognitive resilience is your brain's ability to maintain function even if you accumulate some damage or pathology over time. One of the things people will probably have heard about when we're thinking about dementia or cognitive decline or Alzheimer's disease, is the accumulation of proteins in the brain like amyloid and tau. Resilience is your brain's ability to maintain function even if you do accumulate some of these proteins. One thing we know is really good for building resilience is exercise. People who exercise regularly, even if they have a buildup of some of these proteins in the brain, they get less inflammation and damage because of that protein buildup.

So we have reserve, we have resilience, and then I've come up with a third R of headroom. The third R is resolve. This is basically the idea that if we want more reserve and we want more resilience, we need the resolve to keep doing cognitively challenging things and still keep exercising regularly. Across those three Rs, that's how we can build capacity and maintain it over time. Now I've answered your question about headroom and I've forgotten what your second question was. If you could remind me.

Charlie: Why is it good for people to do things they're not so good at?

Tommy: Yes. When we think about trying to build capacity in the brain, we need to engage a process called neuroplasticity. Neuroplasticity is the process of new connections being made in different areas of the brain related to our experiences or the skills we're building. This is really what allows us to learn, get better at things, and improve our brain health and brain function even very late into life.

When we are trying to engage neuroplasticity, the main thing we need to do is tell our brains we need to change something. Because if you don't need to change something, then nothing changes. One of the strongest signals for driving this process is making mistakes and failing. Because what your brain is doing most of the time, and people may not realise this, is that you are not actually experiencing the world as it happens. You are experiencing the world on a slight delay, most of which is a prediction of what your brain thinks is going to happen next, because it takes some number of milliseconds for everything to get processed and then be spat out. But you still need to exist in the world as it happens.

So the brain is a prediction machine, largely. If you try and do something and you fail at it, there's a difference between what your brain predicts is going to happen and what actually happens. Imagine I'm going to sing some Cher. I think I'm going to hit the high note, and I don't. There's a gap there. My brain's like, hang on a second, something happened. I'm going to have to improve my prediction. I'm going to have to improve my skills in order to hit that note next time I come for it.

Greg: Or we come in with a second round of support for you. We believe in you, Tommy. And that additional support you didn't anticipate then leads you to finally hit that high note right on cue.

Tommy: That could be part of it as well. Getting in the right frame of mind, the right arousal state, is also very important for executing complex skills.

The key point being that when you try and do something you're not good at or not yet an expert at, that signals processes in the brain to say, hey, we need to strengthen these connections. We need to improve our ability to do this specific task. That elicits these processes of neuroplasticity. One way you can feel that is that failing at something inherently feels a little stressful. It's a little uncomfortable. It's why most adults, when you ask me to sing and I refuse to do it, it's why we choose not to engage in things we're bad at, because we hate looking stupid. We hate other people seeing us fail. But when you do fail, that is a primary driver of these processes of neuroplasticity, which helps to build brain structure and brain function as well.

Charlie: Just on building capacity in your brain, though, how do you know when you're at capacity? In terms of, you want to push yourself and try and learn new things. Is there a point when your brain's like, we're at capacity now, this is enough?

Tommy: We've had enough. That's a really good question. If we step back a little bit, if we're trying to think about our brain health long term, and we're already dealing with a tonne of stuff, we have our work and our family and our other commitments, and we're trying to do other things when it comes to our health, and then I show up and I'm like, oh, hey, you should just spend your entire life doing stuff you're bad at because it's good for your brain. Certainly a balance of these things is important. I think all of us will always have the capacity to build additional skills. We may become a true expert in one area, and then you have to put in a lot of effort to get even slightly better.

But the other side is that in the short term, you'll definitely notice that there's only so much time you can spend doing this kind of activity. In reality, people who are trying to learn a complex skill might only be able to spend 30 to 60 minutes at a time. It's hard cognitive work. It requires a lot of focus and attention. There's only so much time we can spend really applying our brains in that way before we need a rest. It's kind of like doing heavy sets of lifting in the gym, or heavy sprints, but for our brain.

You'll notice that your ability to engage and focus will decrease at some point. In the moment, that's your brain probably saying, we've had enough right now. Let's go back, let's rest, to integrate the things you've exposed your brain to. One of the most efficient ways to learn complex skills is to do it every two or three days, because then you actually get the most out of each session. You've rested, recovered, slept in between, got everything you can out of the previous session, and then you can go back and learn again. But I don't really think there's a point where we're just like, oh, there's no space left in my brain.

Greg: You mentioned your three hours earlier, Tommy, and there are also three Ss we'd like to ask you about. We just really like three-letter acronyms here.

Tommy: This is what happens when you write a book. You have to make sort of pithy lists and construct things so people remember them, or so that I'll remember them. So yeah, three Rs and three Ss are probably the core parts of the book.

Greg: The three Ss are part of a framework you use for thinking about what the brain needs to thrive. These are stimulus, supply and support. We've spoken a bit about the stimulus side of things so far, but less about supply and support. Can you walk us through those two and give some examples?

Tommy: Absolutely. There's a whole laundry list of things we know are important for brain health. It's very common. You could go on Instagram and see very well-evidenced lists of 20, 25, 45 things to do for your brain health. But what those lists don't do is give you some idea of how these different pieces fit together. Where should I focus? Do I have to do everything? In biology, most things interact with each other and feed back on each other. It's not just a list of things you have to tackle. So this is the genesis of the three S model.

The first S is stimulus, like you said. This is applying some kind of challenge to the brain, social, cognitive skills, et cetera. When you stimulate an area of the brain, those areas require a supply. So this is our second S, of a variety of things to do the job you're asking them to do. The first thing that happens is the neurons and other cells in those areas of the brain stimulate the local blood vessels to dilate, to bring in more blood flow. For this to work, you need healthy blood vessels. So one important part of supply is good cardiovascular health. We know that cardiovascular disease is a significant contributor to the risk of cognitive decline and dementia.

The next thing we need a supply of is an energy substrate, something to run the cells. For most parts of the brain, for most of us, this is glucose. But there are other substrates you could use, like lactate or ketones. This requires good metabolic health to regulate energy status. We know that blood sugar control, blood pressure, other aspects of metabolic health are really important contributors to cognitive function.

The final supply of things you need is nutrients. Specific nutrients we know are really important for brain health. There are several that we know are associated with cognitive function over time. Things like B vitamins, B12, folate, B6 and riboflavin, which is B2. Then omega-3 fatty acids, vitamin D, iron, magnesium, zinc. There are some other nutrients that play a big role here too, that there's some very interesting research on, like polyphenols from berries and coffee and tea and chocolate, having an antioxidant-type effect. So that's the supply bucket: cardiovascular health, metabolic health, nutrient status.

So you've stimulated the brain, you've brought in all the things needed for that part of the brain to do its job. Like any other tissue in the body, like your muscles when you go to the gym, you don't get stronger in the gym. You get stronger when you recover afterwards. So the third S, support, is this bucket that supports adaptation of the brain to build its capacity. Sleep is obviously a critical part of this. There are other ways we can support our brain. Certain hormones can be really important. When we do things like exercise, we make other proteins that support neuroplasticity, things like brain-derived neurotrophic factor. So trophic support is the fancy word for that.

Then we want to avoid things that impair adaptation. Things like smoking, excessive alcohol, chronic stress, which can affect sleep and several other things. Air pollution, oral health. So dental or gum disease plays a role. These are all acting through things like inflammation, which can impair our brain's ability to adapt. Those are the three Ss, and you can see that they interact as well. When you stimulate the brain, those areas you stimulated actually have a greater sleep drive that night. I think some of the best papers I saw on this were papers that Dr P sent me a few years ago. So we know it's not just this list of stuff. All these different factors come together. What that means practically is that if you change one thing, actually the whole network starts to shift in your favour. This then allows us to think across all those different things I mentioned: what feels like something where I could start to make some movement, it feels doable, enjoyable and sustainable. Because of that, actually many things shift at the same time, and you can build from there.

Greg: The final question before we move to the nuts and bolts of things our listeners can do to keep their brains healthy throughout the lifespan. Tommy, you and I participated in communities online and in person in which evolutionary biology was often used by people to try and back up their ideas. Some of those ideas were sensible. Some of them were less reasonable. But one of the more reasonable concepts is that of mismatch. I wonder if you could explain what mismatch is, because I'm sure it'll come up subsequently in our conversation.

Tommy: In its most simple terms, mismatch is the idea that our bodies expect certain types of inputs, certain environments, certain interactions with the environment, in order to stimulate the biological processes that we might call health. The modern environment has engineered many of those out, so we now have to actively seek them. I think we're now at a stage of extending this mismatch idea. Our brains expect a cognitive challenge, skills, being useful for several decades, and as we get older, maybe becoming teachers, things like that, repositories of knowledge within our group. But because we're starting to engineer thinking out of the environment, we have to now actively seek out challenging things to do with our brains.

Charlie: I've never really thought about it like that.

Greg: So just to play back what you've covered so far, Tommy, before we move to the practice section: you spoke about the fact that cognitive decline isn't inevitable, and actually we can maintain high levels of brain function late into life if we continue to stimulate our minds on an ongoing basis. To support that, we need to do things we suck at, and that helps maintain headroom. Stimulation is metabolically demanding of the brain cells, and that requires an adequate supply of blood to deliver nutrients important for brain health. You touched on some of those. You also mentioned a few foods. I know in your book you speak about other foods too, such as oily fish, which really is a trifecta of goodness for the brain. Subsequently, adequate rest allows the brain to remodel itself, to replete the energy reserves depleted during the activity. Finally, when it comes to thinking about how to support brain health, the concept of mismatch can be helpful. Sometimes we might need to be slightly weird relative to our peers in order to maximise brain health. But it could also be that there are features of our modern lives that will actually let us go above and beyond what we would've been able to achieve in terms of brain health, were we living more traditional pre-industrial lifestyles.

Greg: Sorry for the interlude, but give us a moment to talk about Thriva, the company behind this podcast. Charlie, take it away.

Charlie: Oh, no pressure. So what we do on The Method is try to help you play the long game with health. You know, the whole longevity thing.

Greg: It's a very scientific view.

Charlie: I am trying, Greg, I'm trying. Basically, Thriva is built to help you on that journey to long-term health too. They offer tests you can do at home that give you a picture of your blood markers. The goal is to see where you're starting from, make changes, and retest a few months after.

Greg: They also have a comprehensive app. You can sync your wearable devices like smartwatch or smart ring, information about your health, such as your goals, your exercise habits, how you eat, and collate all of that in one place. This way, over time, you can see relationships between things and identify what's actually working.

Charlie: It is a really simple tool to turn good resolutions into habits that really stick. So check them out at thriva.co. Links in the show notes below.

Greg: Sweet. Now back to today's episode.

Greg: Now that we've explored a few key concepts underlying how to have a healthy functional brain throughout life, let's get to how listeners can put these ideas into practice. You've noted that there's a huge range of stimulating activities, including singing, that people can implement to support their brain health, to maintain their headroom. Can you give us an idea of the scope of these, and what would you say to someone who isn't sure where to start?

Tommy: One of my favourite papers, that I think gives you a good idea of the kinds of activities we might be talking about, was published last year in Nature Communications. It was called Creative Experiences and Brain Clocks. What they did in this study was they took a wide range of people who were either amateurs or experts in creative experiences or creative skills. So it was musicians, tango dancers, visual artists, like painters and drawers. They had video gamers as well. This comes back to what you were saying earlier, Greg, the modern environment doesn't have to be all bad, because there were good things we could get from it.

What they did is they looked at patterns of activity in the brains of individuals who are experts versus amateurs in these complex skills. One of the most important networks they found was something called the fronto-parietal network, which is basically the connection between the front and the middle of the brain. For things like focus and attention and encoding or making memories. With these networks, they built what they called a brain clock, which is basically: if I look at how all the networks in your brain are connected and functioning, how old does your brain look? Because we know as brains get older, these networks become a little bit more unstable.

What they found was that, regardless of age, people who are experts in some kind of complex skill, and it was a variety of skills, music, dance, art, computer games. They even included some data from a randomised controlled trial where they had people learn how to play a computer game. It was StarCraft 2, in case anybody's interested. Although there's lots of great evidence for things like Super Mario 3D World, Minecraft.

Tommy: They've done studies in Minecraft. They've also done studies with action computer games, like Call of Duty even.

Greg: What about the Sega Mega Drive version of Super Mario? I think that was probably about the last computer game I ever played.

Tommy: Wait, Super Mario has to be Nintendo. It can't have been on Sega.

Greg: Lise, cut that.

Charlie: No, I mean, it was a travesty. Keep it in, Lise.

Greg: I'm trying to think when the last time I played a video game was.

Charlie: Game Boy. Tetris.

Greg: Nah, I didn't have a Game Boy. I think it was a Sega Mega Drive. It was probably about 1995.

Tommy: Like Sonic. It might have been Sonic. So what all those games have in common is usually a complex 3D world that you have to explore, problem-solving, rapidly responding to the environment. All these kinds of things help to build very specific and common cognitive skills. So essentially any complex skill seems to be something that can help make your brain act or look younger, maintain processing speed, aspects of executive function, things like decision making. So then somebody who's like, well, where do I start? In reality, you can pick any of those. What sounds interesting to you? There's similar evidence for language learning, music learning, video games. There's even some nice evidence for things like going out and volunteering, because of the social interaction and the novel environments you end up in.

In reality, it's just pick something that feels new but enjoyable, sustainable, where you think you'll suck at it a little bit and you'll get better at it over time.

Charlie: So the three of us are avid exercisers. I know you've just touched on a few there, but many types of exercise, endurance training, resistance training, balance training, coordination training. How many times can I say training in one question? So is there a brain health advantage to combining all these types of activities together?

Tommy: Yes.

Charlie: Next.

Tommy: Do you want me to do a longer answer? Yes, there is. I will now tell you why. Different types of training have different effects on different parts of the brain and different cognitive functions.

So cardio, from brisk walking up to high-intensity interval training, seems to particularly benefit the grey matter of the brain, which is the wrinkly outer part of your brain, as well as some stuff deeper inside your brain, like the hippocampus, which is really important for memory. In those who are sedentary to start with, don't move that much, there was a study where they had individuals do brisk walking three times a week for 40 minutes for a year, and they saw growth in the hippocampus and improvements in memory as people got fitter. This is people in their sixties, where you would normally expect the hippocampus to shrink over time. But there is also an intensity component. Higher intensity does seem to be better.

Charlie: So.

Tommy: I think one of the reasons for this is that many of the factors that get released during exercise, things we call myokines, many of which can have benefits in the brain, they are released in an intensity-dependent manner. Doing more intense exercise, you tend to release more of them. But if you're just starting out, you don't do much movement at all, brisk walking is a great place to start. If you're trying to build from there, then we know that adding some intensity can be beneficial.

Then next you asked about resistance training. A group of us actually wrote a review paper on this a couple of years ago, looking at all the different studies with resistance training, randomised controlled trials with resistance training. What they found is that resistance training once or twice a week for at least six months significantly improves the structure of the white matter and the function of the white matter, in particular executive function. So things like decision-making and rapidly being able to process information. This is probably due to other things that get released during exercise, like IGF-1.

The final thing I want to talk about is what Dr P would call open-skill exercise. This seems to be particularly beneficial for global cognition. This is things like ball sports, racket sports, team sports, martial arts. Dancing is high up on that list as well. They have, in addition to a physical component, a complex motor skill or social interaction, responding to the environment kind of component. So one way we can act on that is, if we're doing some kind of cardio exercise several times a week, say we're jogging or cycling, you could consider instead joining up to play five-a-side football, or badminton, or padel, or pickleball if you're in the US. You're still getting that aerobic cardio type training, but you're layering on some more complex motor skills.

Charlie: I was really hoping you were going to say, try the Macarena when you're running. Introduce some dancing too your running.

Tommy: Thoroughly, that is very much encouraged as well. Absolutely.

Charlie: Not been studied widely though, I'm.

Tommy: No, I don't think we have that in a randomised controlled trial yet.

Greg: I think if you search on clinicaltrials.gov, you'll find that that is actually in progress.

Charlie: It's my favourite website. I know you touched on it very briefly earlier, but when we talk about learning languages to support your brain health, does it matter how you learn? So Duolingo on an app on your phone, or in person with someone?

Tommy: Yes and no. We have evidence from randomised trials that something like Duolingo can improve aspects of executive function in older adults. So people in their sixties and seventies, later in life they're using an app, and they're seeing benefits in terms of their cognitive function. But if you are immersed in this, you're having to interact with another person, you're having to respond to what they're saying, rather than it being in this very formalised, I'm getting my 10-minute streak a day kind of stuff, you are certainly going to get more accelerated learning, and it's going to be more of a cognitive challenge. You are probably going to get more benefits on multiple levels by going to a class and doing this with other people.

Greg: I should probably add that learning to code is a bit like learning a language, and I wonder if there's some similarity in terms of how the brain responds to that versus learning a language.

Tommy: Yes. I actually have some good friends here at the University of Washington who have looked at code learning. Historically, people kind of thought that those who are good at maths would be really good at code. But actually, learning coding is a lot more similar to learning a language than it is to learning algebra or calculus. Those who are multilingual, they tend to be better at learning code, for that reason. That doesn't mean everybody can learn how to code, but it does have, it's not exactly the same, but many of the cognitive processes involved look very similar to learning a language. There's lots of, you're learning phrases and syntax and words, very similar.

Greg: And then final question before we hear from some listeners. Nowadays many of us are using large language models like ChatGPT and Claude on a daily basis for everything, from writing emails to planning holidays to writing code. But some people are also using them for other more questionable things, like online therapy of sorts. Not sure about that practice. In your book, there's a very helpful section about how to use large language models to actually support brain stimulation, rather than just providing a kind of cognitive crutch and crank out shoddy work, because I think a lot of people can see through that nowadays. How can we use forms of AI to actually produce better work while also continuing to stimulate our brains?

Tommy: It's a great question, and this will continue to be, or will become even more important over time. Also we don't know what AI is going to look like in six months, 12 months time. I think it's important to just have a framework for it, regardless of what those tools end up looking like. The way I like to think about it is: when you're using a tool, are you using it to augment a function or your abilities, or are you using it to allow your skills to atrophy?

The way you can use it to build your capacity is to do the work yourself first. An example: there was a study at MIT with students writing essays. What they found was that across multiple different groups and switching over tools and things like that, the highest-quality essays came from students who first wrote the essay themselves, just based on whatever they knew at the time, and then afterwards got access to a large language model and used that large language model almost to throw ideas against, to give feedback to. So you can say, what should I do better, what have I missed, what should I be thinking about? Then you integrate the feedback into the work yourself. You are still actually deploying the skill, you are learning the skill, and then you're using a large language model almost as a second opinion kind of thing. But you're still integrating the feedback yourself.

The alternative, which they showed in this study as well, is that if you use the large language model to start with, and they used ChatGPT in this study, the essay that comes out is more derivative, less unique. The person who quote-unquote wrote it, they remembered it less, they felt less ownership of it, and they didn't actually activate the networks of the brain associated with writing that essay, because they didn't do the work.

So if you are using these tools to do things for you with skills you yourself should have or want to have, you will lose function. You won't practise those skills, you won't activate those networks of the brain, and as a result it's kind of like when you stop training, you lose strength, you lose fitness. It's the same if you're not actually practising those skills, you won't maintain them.

If you can use it instead to extend your capabilities, build something better and learn more through the process of actually doing the work, but then getting input and integrate the input yourself, you could end up building your skills and ending up with a better product.

I can tell when somebody's used a large language model to write me an email. I think email communication is an important skill that we should all maintain. There are other better ways to communicate, in person, et cetera. But I think email communication is an important mode of communication. So I've never used AI to write an email. I didn't use AI when I was writing my book. But I do use AI to help me write statistical code in my work, because it's shortening a part of the work where that skill is less important to me. I don't need to be an expert coder, but I do need to be a good scientist, understand my data, analyse my data, and AI can help me do that and save time so I can do the bit that's actually important, which is analysing and understanding the data as a scientist. So that's how I would approach the use of AI.

Charlie: Yeah, it's really interesting. I write for a living. This isn't my day job. When people send you things that they're like, oh, I've just come up with this. I'm like.

Tommy: Have you?

Charlie: Have you? Because this sounds extremely generic. But it's also, when you talk about, I can remember things that I'm like, I know I've written about this somewhere before, and it'll be in some tender document from two years ago. But when you've written it yourself, you remember what you've written. Yeah.

Charlie: So now we're going to move on to the experience section. This is where we reflect on a couple of listener questions and get your input on those. The first actually relates to the discussion on AI, and is a voice note from Shannon, who lives in Spain.

Shannon: I really worry that technology is having an effect on my brain and my cognition, particularly as I get older, but possibly in general. I was reflecting on this the other day, saying that even just Google has changed things, because now, and this is even exacerbated more with AI, because now we tend to maybe not be clicking around and doing the research within those websites much when it's a simple thing, and so even less exploring. And then also the dopamine hit of social media and phones and immediate gratification. Some of those are definitely having an effect. Is there any research on this? I particularly hear talk about how it's affecting kids and mental health and things, but I'm really just curious if there's any research on how it's impacting our brains and learning pathways and long-term cognition.

Tommy: I think this is something that's on a lot of our minds right now, and understandably so. The AI technological stuff, we sort of touched on already. But one thing we have to acknowledge is that because of technology, the way we're using our brains has changed. But that doesn't necessarily have to be a bad thing.

One good example of this is a very classic study by a researcher called Betsy Sparrow, where they coined the term "the Google effect", which is that we don't have to remember stuff any more because we know we can just Google it. What they did in this study was, they had people learn facts. In one scenario, the computer, they saved these facts on a computer, so they knew they could get access to it later. In the other scenario, they didn't. They thought the computer had destroyed that information, but they would have to remember it later. What they found was that in the former scenario, which is kind of like the modern environment, people were less likely to remember the fact itself, but were more likely to remember where that information was stored. So they were still remembering something, they just changed slightly what they remembered. I would argue that because of the vast amount of information we have to deal with nowadays, that's potentially a useful shift in how we use our memory.

The other group in this study kind of proves that our memory isn't impaired by technology. Because if the group thought that the information had been destroyed, that they couldn't go back and find it, they were more likely to remember it, because they knew they wouldn't be able to go back and find it again. So our memories are still working. We've just shifted how we use them, and I think that's okay. That's going to be a normal part of modern technology.

Other things that come up are different technologies we use at the same time. When we're receiving notifications, emails, things pop up on our phone. Now our watches are tied to our phones, so interruptions are beamed onto our body, which is completely insane. I actually don't have a smart watch for that reason, because I'd literally get nothing done, because my watch would be vibrating the whole time.

Charlie: I can't stand it. I've had to put my phone in work mode 8am to 6pm. Otherwise every time someone messages.

Tommy: If you have a smart watch, that's absolutely what you should do. So one of the reasons we feel fractured and distracted is because we are distracted, by notifications and all these things that pop up all the time. But we have control over that. A lot of this science is based on work by a psychologist called Gloria Mark. She wrote an excellent book called Attention Span, if anybody is interested in this. But basically what happens is we get so used to distractions and interruptions that even when we're not being interrupted by notifications, we go looking for it. We get used to this rhythm of, oh yeah, I can do a minute of work, and then an email's going to pop up and my phone's going to buzz. But you can also train it in the other direction. If you decrease notifications and interruptions, your brain will reset and get used to a different pattern. So part of us feeling distracted and unable to focus is because of this modern notification environment, which we do have control over. You actually probably don't need to know that you got an email right now. Most things in your email aren't urgent. So I would argue we can change our relationship there.

Another thing then is if we're constantly flicking back and forth between different tasks. Some people call it multitasking, but I would argue that the human brain cannot actually multitask. What we're doing is task switching. Every time you task switch, you have this drop in focus and attention as you recalibrate to what you're focusing on next. It's slightly stressful because you never truly feel like you've got a big grasp on what you're trying to do. So at the end of the day, you've had this higher level of chronic stress, you feel less productive. That may then impair your ability to sleep because you're worried about the stuff you didn't do, and it kind of has this feed-forward effect.

But if we can build and protect time to just focus on one thing, just do some high-quality work, and then separately do those emails and meetings and things that might require a little bit of task switching, we can chunk that out, and again maybe feel a little bit more productive and maintain our ability to focus. One reason we feel like we can't focus is because we just don't spend time being focused. If you spend time being focused, you can learn how to focus again. If you spend time doing things like mindfulness, which is essentially just focusing on one thing, like your breath or a body scan, you improve your ability to focus. So we can retrain it. The skill isn't lost.

Charlie: How long does it take, roughly?

Tommy: Within even two or three weeks you might start to see improvements. The final piece of good news is that there are some very recent studies that show that when you take people out of the modern, distracted, multimedia, notification-type environment, and you put them in a lab and just have them do one thing at a time, we are not more distractible and unfocused now than we were say 10 or 20 years ago. It's the environment and all this kind of stuff that's driving it. So our focus has not been lost. All of that to say that if we can restructure that a little bit, change or decrease our notifications and distractions, we are capable of focusing.

Charlie: We just have to be a little bit more mindful. Very interesting. So doom scrolling isn't that bad.

Charlie: Our final question is a written question from Harry, who is based in Somerset, and he has asked, "I'd like to know how deep into learning a new skill do you have to go to see the benefits for an ADHD brain like mine? I'm excited by a new sport or activity, but often move on to something new quite quickly. Is that constant challenge better, or worse? Or novelty versus mastery?"

Tommy: This is a great question, and I don't think there's a perfect answer here. What we do know is that the early part of the learning curve is where you get the most benefit. You're learning the most, you've gained the most, you build the initial networks required to do this specific task or skill. But most studies might look at skill learning or sport learning in two or three month blocks, and you can see significant benefits there. So if Harry is doing a new skill every week, that's probably not long enough to really start to benefit from it. But because that early part of the learning process is maybe where you get some of the biggest benefits, I think it's okay to rotate things you're doing.

But there does seem to be some true benefit from becoming a real expert in something. So there's going to be a bit of a balance between how long does it feel like something is engaging, interesting, enjoyable, because that's going to be really important, versus is it worth really investing a tonne of time in something just to get incrementally better gains if you feel drawn to do something else? I think investing in something for a few months is probably a great kind of target. Six to twelve months perhaps, if you're doing it once or twice a week, for example. And then maybe rotate.

Charlie: Amazing.

Greg: We'll bring things to a close now, and I'll end by pointing people in the direction of your excellent book, The Stimulated Mind. Congratulations, Tommy. Well done, mate. There are lots of things in the book that we didn't get to, and that's all the more reason for people to go and buy a copy. They include the likes of nutrition and sleep concepts, the importance of relationships, which you've alluded to but we didn't really explore, and also how to structure your work day for productivity. So there's a lot more to glean from the book. But to close, what's one thing that you'd like our listeners to take away from this episode?

Tommy: Can I, I'm going to give you two. But if it's going to be one, then the one thing to take away is the knowledge that our brains don't automatically decline over time, and we have a lot of agency in that process. It's important for that to be number one, because if you don't realise or know that, you won't do any of the other stuff because you don't think it's worthwhile doing. Then number two, my cheeky number two, is going to be: anything we've talked about today that feels doable, enjoyable, worthwhile, just one thing, that's the place to start. Because when you do one thing, you're actually doing many things at once.

Greg: Crumpet, what are your key takeaways from today?

Charlie: That Tommy was in multiple choirs. Shouldn't be the key takeaway though. Cognitive decline aged 50 to 80, you can avoid it, actually. Which is really interesting, because I do think a lot of people assume as soon as you hit 50, 60, that's it, it's a downward spiral from there. So very interesting to hear that, actually, not all is lost. I was actually quite interested with the fact that on the creative skills, gaming was in there. Because I do think a lot of people have a misconception with gaming, don't they? With, you're just sitting in front of a screen. But it's actually really impressive.

Greg: And there is a little bit of transfer to some other skills too. So it's not all bad. I think some people have the impression that it is. Parents often feel that way. But used judiciously, it can actually be good for the brain.

Charlie: Yeah. Maybe not 12 hours a day. Not moving, not walking.

Greg: Maybe not.

Charlie: What are your key takeaways?

Greg: It reminds me of the episode with Vish. In that episode, Vish emphasised the importance of starting somewhere. I know Tommy thinks about these issues through a similar lens. Going back to a metaphor we've used, if you pull one lever, like changing your physical activity, you could possibly affect a huge range of different health outcomes, because of the fact that everything in the system is related. So if you want a healthy brain, when your motivation is waning, just doing something is what matters. Simple things like brushing your teeth while standing on one leg, eating some oily fish to supply nutrients for your brain, doing very simple things to support your sleep health, for example, having a hot bath or hot shower an hour before we go to bed. The support can all be helpful. So just start somewhere. Think about what you can do when you are at your worst. And if there is a more complex skill you're interested in picking up, then you can do your brain a huge amount of good by practising that on a regular basis.

Charlie: You've been listening to The Method: Health in the Real World, a podcast brought to you by Thriva.

Greg: If you don't know about Thriva, it's a health tracking platform that helps you see where your health is heading and what to work on, as well as how to do it. They use painless at-home blood testing to look inside your body and see what's going on. Your tests are analysed by accredited labs, and based on the results, which are reviewed by doctors, you get personalised guidance from real people. People use Thriva like compass testing every few months to help steer their health to where they'd like it to be. It's a great tool to start feeling more empowered about your health, and to get information you need to make progress even when life is chaotic.

Charlie: Thriva also has some great content out there that can help you get to grips with complex health questions, exactly like what we're trying to do on this podcast. All of that is free to access. So if you want to learn more, head over to thriva.co. That's thriva.co.

Greg: And if you want to listen to Charlie sing really, really well, subscribe to the show. Come back every week for more tunes. You won't be disappointed.

Charlie: Well, unless you beg me to stop. But even then, probably not.

Greg: You can find us by email at themethod@thriva.co.

Charlie: Seriously, we'd love to hear all of your questions, and your voice. We love a voice note.

Greg: Special thanks to the Thriva team and to Lower Street for helping us bring the show to life. Content direction by Rich Cousins, Hamish Grierson, Tamar Loach, Vishal Shah and Katie Yockey. Production by our resident yogi Lise Lovati, as well as Ryan Sutton and Sam Datta-Paulin. Sound design by Alex Rose.

Charlie: We are your hosts, Charlie Edmondson and Greg Potter, and we will see you next time.

Greg: Thanks, and bye.

Disclaimer: This information is for general educational purposes only and isn't a substitute for professional medical advice, diagnosis, or treatment. Always speak with a qualified healthcare professional first if you have concerns about your health.

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