Boost Attention & Memory with Science-Based Tools | Dr. Wendy Suzuki

Andrew Huberman 0:00 (uptempo music) 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. Today, my guest is Dr. Wendy Suzuki. Dr. Suzuki is a professor of neuroscience and psychology at New York University and one of the leading researchers in the area of learning and memory. Her laboratory has contributed fundamental textbook understanding of how brain areas such as the hippocampus, which you will learn about today, how the hippocampus and related brain circuits allow us to take certain experiences and commit them to memory so that we can use that information in the future. Dr. Suzuki is also an expert public educator in the realm of science. A few years back, she had a TED Talk that essentially went viral, if you haven't seen it already, you should absolutely check it out, in which she describes her experience using exercise as a way to enhance learning and memory, and on the basis of that personal experience, she reshaped her laboratory to explore how things like meditation, exercise, and other things that we can do with our physiology and our psychology can allow us to learn faster, to commit things to memory longer, and indeed, to reshape our cognitive performance in a variety of settings. As such, I am delighted to announce that Dr. Suzuki is now not only running a laboratory at New York University, but she is the incoming Dean of Arts and Science at New York University, and, of course, she was selected for that role for her many talents, but one of the important aspects of her program, she tells me, is going to be to incorporate the incredible power of exercise, meditation, and other behavioral practices for enhancing learning, for improving stress management, and other things to optimize student performance. Today, you are going to get access to much of that information so that you can apply those tools in your daily life as well. Dr. Suzuki is also an author of several important books. The most recent one is entitled Good Anxiety: Harnessing the Power of the Most Misunderstood Emotion, and a previous book entitled Healthy Brain, Happy Life: A Personal Program to Activate Your Brain and Do Everything Better, and while that is admittedly a very pop science-type title, I will remind you that she is one of the preeminent memory researchers in the world and has been for quite a while. So, the information that you'll glean from those books is both rich in depth and breadth and is highly applicable. By the end of today's discussion, you will have learned from Dr. Suzuki a large amount of knowledge about how memories are formed, how they are lost, and you will have a much larger kit of tools to apply for your efforts to learn better, to remember better, and to apply that information in the ways that best serve you.

Andrew Huberman 2:50 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, I'd like to thank the sponsors of today's podcast. Our first sponsor is Athletic Greens. Athletic Greens is an all-in-one vitamin, mineral, probiotic drink. I've been taking Athletic Greens since 2012, so I'm delighted that they're sponsoring the podcast. The reason I started taking Athletic Greens and the reason I still take Athletic Greens once or twice a day is that it meets all my foundational vitamin, mineral, and probiotic needs. In fact, whenever people ask me if I were to only take one supplement, which supplement should I take, I tell them Athletic Greens for the simple reason that it covers your base of vitamins, minerals, and probiotics. 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So once again, if you go to athleticgreens.com/huberman, you can get a special offer of five free travel packs to make it easy to mix up Athletic Greens while you're in the car or otherwise traveling, plus they'll give you the year's supply of vitamin D3 K2. Today's episode is also brought to us by InsideTracker. InsideTracker is a personalized nutrition platform that analyzes data from your blood and DNA to help you better understand your body and help you reach your health goals. I've long been a believer in getting regular blood work done for the simple reason that many of the factors that impact your immediate and long-term health can only be analyzed from a quality blood test. And nowadays, with the advent of modern DNA tests, you can also get insight into, for instance, what your biological age is and compare that to your chronological age, and of course, your biological age is the, the number that really matters. 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I like the actual physical book, I'm sort of old-fashioned in that way, and I do also listen to audiobooks. It's very rare that I don't.... finish a book that I've started. Nonetheless, I like to revisit some of my favorite books. I also like to write down key takeaways from those books, sometimes even before I listen to the full-length book. So I don't mind spoiling the, the takeaways because when I read nonfiction, generally I'm trying to extract the most valuable knowledge from them. So I'll often listen to a Blinkist 15-minute version, then the full-length book, or sometimes the full-length book and then the Blinkist 15-minute version. Either way, Blinkist is a great way to get through any book and to extract the best from those books. I've used it for, for instance, Matt Walker's Why We Sleep, an excellent book on why we sleep, as well as Tim Ferriss' The 4-Hour Body, uh, Nassim Talle's The Black Swan, and so on and so on. 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Andrew Huberman 7:28 Wendy, great to see you again and to have you here. It's been a little while.

Dr. Wendy Suzuki 7:31 It's been a while. So great to be here, Andrew. Thank you so much for having me.

Andrew Huberman 7:35 Yeah, delighted. I'd like to start off by talking about memory generally, and then I'd love to chat about your incredible work discovering how exercise and memory interface and what people can do to improve their memory and brain function generally.

Dr. Wendy Suzuki 7:51 Yes.

Andrew Huberman 7:51 But for those that are not familiar, maybe you could just step us through the basic elements of memory, a few brain structures perhaps.

Dr. Wendy Suzuki 8:00 Sure.

Andrew Huberman 8:01 You know, what happens when I. For instance, this mug of, uh, tea, uh, it's pretty unremarkable.

Dr. Wendy Suzuki 8:06 Mm.

Andrew Huberman 8:07 But the fact that now I've talked about it-

Dr. Wendy Suzuki 8:09 Yeah.

Andrew Huberman 8:09 ... I don't know that I'll ever forget about it.

Dr. Wendy Suzuki 8:11 (laughs)

Andrew Huberman 8:11 Maybe I will, maybe I won't. So what happens when I look at this mug and decide that it's something special for whatever reason?

Dr. Wendy Suzuki 8:20 Yeah. Well, I like to say there are four things that make things memorable. Number one is novelty. If it's something new, the very first thing, uh, v- very first time we've seen something or experienced something, our brains are drawn to that, our attentional systems draw us to that. And when you are paying attention is something that's, that's part of what makes things memorable. Second is repetition. If you see that cup of tea every single day and every single time you do an interview you talk about your cup of tea, you're gonna remember it. That's just, uh, uh, how, how our brains work, repetition works. Third is association. So if you meet somebody new that knows lots of people that you know, so you and I share many, many, many, many people that we both know-

Andrew Huberman 9:11 Mm-hmm.

Dr. Wendy Suzuki 9:11 ... it's easy to rememb- it's easier to remember you, especially if you were somebody new that I hadn't met before, we have met before. Uh, so association. Um, and then the fourth one is emotional resonance. So we remember the happiest and the saddest moments of our lives, and that also includes, you know, funny, surprising things. Uh, that is the interaction between two key brain structures, uh, the amygdala, which is important for processing, uh, lots of emotional, particularly threatening kinds of situations, but, uh, those threatening, surprising kinds of situations, the amygdala takes that information and makes another key structure called the hippocampus work better to put new long-term memories in your brain. So that, in fact, is the key structure for long-term memory, the structure called the hippocampus.

Andrew Huberman 10:08 Fantastic, so novelty, repetition, association, and emotional resonance.

Dr. Wendy Suzuki 10:13 Yes.

Andrew Huberman 10:14 Could you tell us a bit more about the hippocampus?

Dr. Wendy Suzuki 10:16 Yeah.

Andrew Huberman 10:16 I think, um, at least for my generation, uh, well, I'm a neuroscientist, but for most people in my generation, I think they first heard about the hippocampus from the movie Memento.

Dr. Wendy Suzuki 10:24 Oh, yeah, yeah.

Andrew Huberman 10:25 Where the guy says hippocampus.

Dr. Wendy Suzuki 10:27 Yeah. (laughs)

Andrew Huberman 10:28 Um, and if, for those of you that haven't seen that movie, it's a bizarrely constructed movie, but an interesting one, nonetheless, um, about memory. But even as a neuroscientist, sometimes I'm perplexed at how, uh, the hippocampus works.

Dr. Wendy Suzuki 10:43 Mm.

Andrew Huberman 10:43 You know, maybe you could, if you w- wouldn't, if you would, you know, step us through kind of what this structure is, what it looks like-

Dr. Wendy Suzuki 10:49 Yeah.

Andrew Huberman 10:49 ... um, maybe a few of its subregions because-

Dr. Wendy Suzuki 10:51 Right.

Andrew Huberman 10:52 ... um, you know, unlike vision-

Dr. Wendy Suzuki 10:54 Mm-hmm.

Andrew Huberman 10:54 ... the topic that I've worked most of my career on-

Dr. Wendy Suzuki 10:57 Yeah.

Andrew Huberman 10:57 ... where we know, okay, the eye does this part, and the thalamus does this part, and the cortex does that part, I've always been a little perplexed about the hippocampus, frankly.

Dr. Wendy Suzuki 11:04 Hmm. Okay.

Andrew Huberman 11:04 So, um, and I've read the textbooks and I've heard the lectures, but-

Dr. Wendy Suzuki 11:07 Yeah.

Andrew Huberman 11:07 ... I'd love to get the update. You know, what are the general themes of the hippocampus as a structure-

Dr. Wendy Suzuki 11:12 Yeah.

Andrew Huberman 11:12 ... and its function?

Dr. Wendy Suzuki 11:13 Yeah.

Andrew Huberman 11:13 Um, what do you think everyone, including neuroscientists-

Dr. Wendy Suzuki 11:16 Mm-hmm.

Andrew Huberman 11:16 ... uh, should know about the hippocampus?

Dr. Wendy Suzuki 11:18 Absolutely. So let's start with the basics. The word hippocampus means seahorse. It is shaped, the structure is shaped like a kind of curlicue she- seahorse. That is accurate. Um, everybody, including neurosci- scientists should know it's a beautiful structure. It is visually anatomically beautiful with these kind of intertwining twirly subregions within it. And I think that's one of the reasons why early anatomists, who were the very first neuroscientists, got attracted to it, because it's this interesting kind of twirly structure deep in the heart of the brain. So that's anatomically. Functionally, what does it do? Well, it's easiest to understand what it does when you, uh, look at what happens when you don't have a hippocampus anymore. What if you, what if by some, you know, disease or, or you have your hippocampus removed by accident, um, what happens? Well, we know this from the most famous neurological pac- patient of all time. Uh, his, uh, initials were HM, so all psychology and neuroscientists, neuroscience students know him. Uh, he was operated in 1956.... four, and the paper was published in 1957. Um, they removed both his hippocampi because he had very terrible epilepsy. And, um, they knew that the hippocampus was the genesis of- of epilepsy, and this was experimental. His epilepsy was so bad that they decided not just to remove one hippocampus, but both. And what happened was immediate, um, immediate loss of all ability to form new memories for facts and events. Think about that for a second. All facts or events you're not able to remember, I can't remember this interaction between us, I can't remember any of the facts that we were just chatting about in our neuroscience lives. Um, none of that can move into our long-term memory. So this hippocampus does something with all of these perceptions that are coming at us every single day, every minute of the day, and not for all of them, but for some of them that have these features that we just talked about, maybe they're novel, maybe they have associations, maybe they're- they're emotionally relevant, maybe, uh- uh, maybe they've r- been repeated. Some of those things, uh, in the realm of facts or events get, uh- uh, encoded in our long-term memory. And, um, that's- that's the textbook of- of why the hippocampus is so important. I like to always add, and, I mean, this is why I studied it for so many years, the hippocampus and what it does really defines our own personal histories. It means it defines who we are because if we can't remember what we've done, the information we've learned, and- and the events of our lives, it- it changes us. That- that's what really defines us. That's why I wanted to study the hippocampus. And I think the exciting new- new ideas about the hippocampus was, um, is that it's- it's, you know, hippocampus is important for memory, so if you say that you'll be- impress all your people at your, uh, at your cocktail party. But what people have started to realize, that it's not just memory. It's not just putting together associations for what, where, and when of- of events that happened in our past, but it's putting together information that is in our long-term memory banks in interesting new ways. I'm talking about imagination. So without the hippocampus, yes, you can't remember things, but actually you're not able to imagine, uh, events or situations that you've never experienced before. So what that says is the hippocampus, eh, is important for memory is, uh, too simple a way to think about it. What the hippocampus is important for is what we've already talked about, associating things together writ large. Any time you need to associate something together either for your past, your present, or your future, you are using your hippocampus. And it takes on this much more important role in our cognitive lives when we think about it like that. That is kind of the new- the new hippocampus that- that neuroscientists are studying these days.

Andrew Huberman 15:52 Well, that's fantastic. So it sounds like it really sets context, but it can do that with elements from the past, the present-

Dr. Wendy Suzuki 15:58 Yeah.

Andrew Huberman 15:59 ... or the future.

Dr. Wendy Suzuki 15:59 Yes.

Andrew Huberman 16:00 And at the ti- uh, well, for neuroscientists, the- the phrase is domain, we say the time domain-

Dr. Wendy Suzuki 16:05 Yes.

Andrew Huberman 16:05 ... uh, meaning as opposed to just evaluating things in space, it sounds like the time domain of hippocampal functioning is incredibly interesting.

Dr. Wendy Suzuki 16:13 It is.

Andrew Huberman 16:13 And- and even the fact that we can have short-term, medium-term, and long-term memories. And we could go down any of these rabbit holes.

Dr. Wendy Suzuki 16:19 Yeah. (laughs)

Andrew Huberman 16:19 Um, I'll

Andrew Huberman 16:20 ask you a true or false mostly-

Dr. Wendy Suzuki 16:21 Okay.

Andrew Huberman 16:21 ... because I just really want to know the answer.

Dr. Wendy Suzuki 16:23 Okay.

Andrew Huberman 16:24 Uh, a few years ago, the theme in various high-profile reviews seemed to be that the hippocampus was involved in encoding and creating memories, but not in storing memories, and that the memory storage was in the neocortex or the other overlying areas of the brain. Is that too general a statement?

Dr. Wendy Suzuki 16:41 Um, that's a- that's a tricky statement because I think that ultimately yes, that long-term memories are stored in the cortex, but those memories are stored in the hippocampus sometimes for a very, very long time. So how long is too long where you say, "Oh, it's not the hippocampus anymore"? If it's four years, is that, (laughs) does that mean that it's, you know, it- it's not stored in the hippocampus? I think that's a- that's a tricky question. And yes, it was coming up a lot because people were debating it and- and some people did think that you shouldn't think about the hippocampus as a storage area, but I think it's a long, long, long-term kind of intermediate storage area, maybe not the long-term storage area. That's why it's hard to answer that question.

Andrew Huberman 17:30 Great. Uh, as I recall, (laughs) HM could remember facts from before his surgery.

Dr. Wendy Suzuki 17:37 Yes.

Andrew Huberman 17:37 He couldn't form new memories.

Dr. Wendy Suzuki 17:38 Correct.

Andrew Huberman 17:39 And given that he had no hippocampus, it would at least partially support the idea that some, uh, memories are retained outside the hippocampus.

Dr. Wendy Suzuki 17:47 However, he did have part of his posterior hippocampus intact.

Andrew Huberman 17:52 Ah.

Dr. Wendy Suzuki 17:52 So that's the tricky thing. I think initially, um, in fact, Scoville, the- the neurosurgeon, overestimated the number of millimeters he had want- he intended to remove of the hippocampus, and then when they did this, uh, the- the very historic MRI of HM later in his life, they showed that, in fact, he did have that posterior hippocampus, part of the posterior hippocampus, intact. So now it makes- makes it a little bit more complicated to interpret what's going on, not that it was never uncomplicated. Any interpretation of a lesion in- in a patient, as you know, is complicated, but, um, you know, HM had this mythical role in- in neuroscience and neurology, and now it was- it was- it was complicated because he- he does have more of the hippocampus intact.

Andrew Huberman 18:45 I did not know that. Uh,

Andrew Huberman 18:48 there are some memories that can be formed very quickly, so-called one trial learning.

Dr. Wendy Suzuki 18:54 Yeah.

Andrew Huberman 18:54 And I'm just looking at this list again, novelty, repetition, association, and emotional resonance. Uh, it seems like some experiences can bypass the need for multiple repetitions.

Dr. Wendy Suzuki 19:06 Yeah, absolutely.

Andrew Huberman 19:06 So, um, I, and unfortunately it seems that our nervous system is skewed toward creating one trial memories-

Dr. Wendy Suzuki 19:14 Yeah.

Andrew Huberman 19:15 ... for negative events-

Dr. Wendy Suzuki 19:16 Right.

Andrew Huberman 19:16 ... which has a survival adaptive mechanism.

Dr. Wendy Suzuki 19:18 Yeah.

Andrew Huberman 19:19 What is the neural connection that allows that to happen? Is it the amygdala to hippocampus connection? I mean, as you and I know, the, seems like every brain area ultimately is connected to everything else.

Dr. Wendy Suzuki 19:29 Right, right.

Andrew Huberman 19:29 It's just a question of, uh, through how many nodes.

Dr. Wendy Suzuki 19:31 Yeah.

Andrew Huberman 19:31 Just like every city is connected to another city.

Dr. Wendy Suzuki 19:33 Right.

Andrew Huberman 19:33 It's just a question of how many flights and roads-

Dr. Wendy Suzuki 19:35 Yeah.

Andrew Huberman 19:35 ... do you have to, uh, traverse before you-

Dr. Wendy Suzuki 19:39 Yeah.

Andrew Huberman 19:39 ... uh, get there. What is it about one trial learning? I mean, at, at a kind of top contour level, how do we, how can we learn certain things so fast-

Dr. Wendy Suzuki 19:49 Yeah.

Andrew Huberman 19:49 ... and other things are, are tricky? And now every time I look at this white mug, it's queuing up something special that-

Dr. Wendy Suzuki 19:54 (laughs)

Andrew Huberman 19:54 ... simply by virtue of saying it.

Dr. Wendy Suzuki 19:56 Yeah.

Andrew Huberman 19:56 So is that one trial memory? But, uh, you know, what is, what is it about very emotionally salient events that allow memories to get stamped in?

Dr. Wendy Suzuki 20:06 Yeah, I mean, I think you, you, you've already alluded to it. That is, there is this protective function, um, of our brains that has evolved over the last 2.5 million years, that you need to pay attention and remember certain things for your survival. So some things that get stamped in, um, you know, th- they're memories, but they're, they're fear memories. You know, if I get mugged on the s- subway or, you know, there are terrible things that could happen on the subway as we, as we just learned. Um, but if something terrible happens, if something very scary happens, um, you remember that, and that, that fear and that memory of all those things... I mean, I, I have one. Uh, when I lived in Washington, DC, I went to work at NIH on a Sunday afternoon, and I came back and when I rounded the corner to my door of my apartment, um, it was crowbarred in. Somebody had taken a crowbar, opened up my door, and stole all of my, all of my, the nicest things in my apartment, which wasn't that nice 'cause I wasn't making that much money. But ever since, um, ever since then, whenever I rounded that corner, I still had that memory. It was terrible because, you know, it put me in a terrible state w- when I was just coming home. And that, that's a survival mechanism. Do you want to, uh, be alert to possible danger? Absolutely, yes. So part of those one trial memories I think is often taking advantage of this evolutionarily developed system to tamp in things that could be potentially dangerous to you into your memory so you forever will remember this particular corner or this, this, uh, hallway because that is where something really bad happened to you.

Andrew Huberman 21:56 It seems like a location, we talk about conditioned place aversion-

Dr. Wendy Suzuki 22:00 Yes, yeah.

Andrew Huberman 22:00 ... which is just geek speak for wanting to avoid the place where something bad happened, or conditioned place preference, wanting to go back to a place where something positive happened, or even looking at a photograph of where you had a wonderful time with somebody and that can evoke all sorts of, um, positive sensations. It seems like at some level the, as complex as the brain is, the basic elements of, uh, feeling good or feeling lousy are, are states within the brain and body.

Dr. Wendy Suzuki 22:26 Mm-hmm.

Andrew Huberman 22:26 And linking those to places seems like it, it's a pretty straightforward formula, you know, s- link place to state-

Dr. Wendy Suzuki 22:32 Uh-huh.

Andrew Huberman 22:33 ... link state to place, et cetera-

Dr. Wendy Suzuki 22:34 Yeah.

Andrew Huberman 22:34 ... as your, uh, description just provided. When we learn more complex information-

Dr. Wendy Suzuki 22:39 Mm.

Andrew Huberman 22:39 ... you know, uh, a, a poem, um, a, a concept, or we have to ratchet through a set of ideas, uh, that also involves memory.

Dr. Wendy Suzuki 22:49 Yeah.

Andrew Huberman 22:51 I'm sure that we'll talk more about this, but is there any way that, uh, you, you are aware of that state, bodily state can be leveraged to enhance the speed or the, the quality of the r- of memories and memory formation? Because, you know, the, so t- to be clear about it, it seems there's something very important about this fourth, uh, you know, this emotional resonance-

Dr. Wendy Suzuki 23:17 Mm-hmm.

Andrew Huberman 23:17 ... component.

Dr. Wendy Suzuki 23:18 Yeah, yeah.

Andrew Huberman 23:18 Right? Um, novelty, the crowbar into the door is-

Dr. Wendy Suzuki 23:21 Mm-hmm.

Andrew Huberman 23:22 ... thank goodness is a f- sounds like it was novel, it wasn't a repeated theme, thank goodness.

Dr. Wendy Suzuki 23:26 Yes. You're right, right.

Andrew Huberman 23:26 So repetition is out, and the association is very, very strong.

Dr. Wendy Suzuki 23:29 Mm-hmm.

Andrew Huberman 23:30 But for people trying to learn information that they're not that excited about-

Dr. Wendy Suzuki 23:34 Right.

Andrew Huberman 23:35 ... or that, um, repetition is hard-

Dr. Wendy Suzuki 23:37 Mm-hmm.

Andrew Huberman 23:38 ... or the, the novelty is simply that it's painful.

Dr. Wendy Suzuki 23:42 (laughs) Yes. I've been there, absolutely.

Andrew Huberman 23:45 Yeah, yeah, uh, yeah, as, as have I. I- is there something that we can do to le- to leverage knowledge of how the memory system works naturally to, to make that a, a more straightforward process?

Dr. Wendy Suzuki 23:57 So I, I immediately turn to, um, the things that I've studied that you talk about so beautifully on your podcast, which are, uh, strategies generally to make your brain work better. I was just reminding myself of your podcast about cold, uh, um, because I use that every morning.

Andrew Huberman 24:22 Oh, oh, you do cold?

Dr. Wendy Suzuki 24:22 I do, I do.

Andrew Huberman 24:23 Just take a moment and, and just tell us, what is your cold exposure protocol?

Dr. Wendy Suzuki 24:26 So my cold-

Andrew Huberman 24:26 Then I'll take you back to what you're saying.

Dr. Wendy Suzuki 24:27 Okay, so my cold exposure protocol is, uh, at the end of every morning shower that I, that I take, um, you know, y- the shower is, is warm, but I give myself a big blast of cold at the, at the end of that, and-... it makes me feel so good, and because I've been doing it for several years, it's so much less painful. Okay, I admit, it was really painful at- at- at the beginning. Um, but it's much less painful. I could- I could handle the cold water and my pipes are give nice, really cold water, um, and it just, I could feel, I could feel the- the awakeness kind of come- come up in me after that. And so, um, and I miss it if I forget to do it. Sometimes I run back in and give myself that cold blast because it is- it is upping, you know, I think you talked about this on your podcast, what's happening in the brain?

Andrew Huberman 25:23 It basically, the cold stimulus, that shock-

Dr. Wendy Suzuki 25:26 Yeah.

Andrew Huberman 25:26 ... that, you know, catching your breath, et cetera, is adrenaline from the adrenals. But also, from what we understand now, some new neuroimaging, there's epinephrine and norepinephrine re- released from locus coeruleus-

Dr. Wendy Suzuki 25:38 Yeah.

Andrew Huberman 25:38 ... which, again, is a brain structure in the back of the brain, kind of sprinklers the- the rest of the brain with- with a kind of a wake-up chemical, and there's a long arc on dopamine release.

Dr. Wendy Suzuki 25:47 Mm-hmm.

Andrew Huberman 25:47 This paper back in 2000 showed that it's a steady increase up to about 2.5x of circulating dopamine.

Dr. Wendy Suzuki 25:53 Yeah.

Andrew Huberman 25:54 So they weren't looking directly in the brain, admittedly, but it goes on for four or five hours.

Dr. Wendy Suzuki 25:58 Wow, yeah.

Andrew Huberman 25:59 So the improved mood and the feeling of alertness is a real thing.

Dr. Wendy Suzuki 26:02 Yeah, yeah.

Andrew Huberman 26:03 Yeah.

Dr. Wendy Suzuki 26:04 So- so I use tha- I mean, so basically, I use my morning routine, what is my morning routine? I get up. I do a, um, 45-minute tea meditation, so meditating over the brewing and drinking of tea that I learned from a monk, um, who has a institute in Taiwan, where he teaches tea meditation. Love it. I've learned all about tea, um, different kinds of tea, uh, and then I do a 30-minute cardio, uh, cardio weights workout. Um, then I take my shower with the- with the hot-cold contrast. Um, and, oh, and before that, key thing, if I want to learn something and- and I want to be able to, um, get over the- the- th- th- the difficulty of r- repeating things or just- just push myself to do stuff, sleep. So good, good sleep. I've learned that over the pandemic, um, I did sleep experiments on myself and I learned that I was sleeping an hour less than I really needed. So I really need seven and a half to eight hours of sleep, and I was getting six and a half. And so now, you know, I get- get that seven and a half to eight hours every single night, and guess what? I come to different difficult tasks and I am more willing to give it a try, to try longer, to try harder, and my brain works better. And so I think probably if you go back to all of your podcasts, you'll learn exactly why each one of those things that I do, which I would bet that you probably do too, is helping my brain.

Andrew Huberman 27:39 Uh, I guarantee they are, and I'm- I'm impressed that you do all these things, although not surprised. And I should say that the extra hour of sleep is really impressive, um, and extremely beneficial. I'm curious, do you get that, uh, in the early part of the night by going to bed earlier?

Dr. Wendy Suzuki 27:54 Yeah.

Andrew Huberman 27:54 Or are you...

Dr. Wendy Suzuki 27:55 Yeah.

Andrew Huberman 27:55 Terrific, and- and I should just mention, um, 'cause you're too humble to do it, but I'll say it again, that, yes, not only are you a full professor running a- a tenured full professor and running a laboratory, you teach undergraduates, you have a- an important role in public education, multiple books, and you're now dean of the- the- the College of Arts and Sciences at NYU. So the extra hour of sleep is benefiting you and in- and as a consequence, uh, benefiting everybody else as well.

Dr. Wendy Suzuki 28:22 Yes.

Andrew Huberman 28:22 Thanks for sharing with us your protocol. I took you off the trajectory of what one can do.

Dr. Wendy Suzuki 28:26 (laughs)

Andrew Huberman 28:26 But I- I think that people and- and I appreciate knowing, you know, kind of what the practical steps are.

Dr. Wendy Suzuki 28:32 Yeah, yeah.

Andrew Huberman 28:33 Because knowing the science is important, mechanism, I do believe, is- is important for embedding, uh, protocols in people's minds and why they might want to do them, but really hearing the- the- the mechanics of it is useful.

Dr. Wendy Suzuki 28:43 Right.

Andrew Huberman 28:43 It sounds like everything together takes about an hour, it's not an excessive amount of time, but it probably gives you an outsized, positive effect on- on your day.

Dr. Wendy Suzuki 28:51 Oh, yeah. Absolutely, I definitely notice it, um, if I'm not able to do it, uh, and- and when I don't, so I- I do this seven days a week. It's also not just, you know, five days, seven days a week, and, um, when I can't do it, it's usually early morning flights or things like that and- and, um, and I get over it, but it's, uh-

Andrew Huberman 29:13 Good.

Dr. Wendy Suzuki 29:13 ... critical, critical for the working of my brain.

Andrew Huberman 29:16 I love it, and I'll just highlight one thing that you said, uh, before we move on, which is that you said when sometimes w- if you get out of the shower before the cold, you'll get back in.

Dr. Wendy Suzuki 29:24 Yeah.

Andrew Huberman 29:24 That's, to me, a- a really beautiful example of conditioned place preference, you know?

Dr. Wendy Suzuki 29:28 (laughs) Exactly.

Andrew Huberman 29:28 There's some- now the cold shower has become something that you sort of look forward to. I should say that nobody is immune from the adrenaline increase of cold, no matter how cold it i- this is what's interesting about cold, it's one of the reasons why it's such an important part of the screening for special operations-

Dr. Wendy Suzuki 29:43 Mm-hmm.

Andrew Huberman 29:43 ... you know, so our SEAL teams-

Dr. Wendy Suzuki 29:44 Yeah.

Andrew Huberman 29:44 ... but other- other, uh, branches of military too, which is that there fair- very few stimuli that you can give anyone-

Dr. Wendy Suzuki 29:52 Uh-huh.

Andrew Huberman 29:52 ... and consistently get an adrenaline-

Dr. Wendy Suzuki 29:55 Oh, interesting.

Andrew Huberman 29:56 ... release from that without harming them.

Dr. Wendy Suzuki 29:58 Uh-huh.

Andrew Huberman 29:58 You know, with heat, eventually you need to use so much heat that you damage tissue-

Dr. Wendy Suzuki 30:01 Yeah. Yeah.

Andrew Huberman 30:02 ... or with exercise, you have to use so much exercise that you can damage joints and-

Dr. Wendy Suzuki 30:05 Yeah.

Andrew Huberman 30:05 ... you know? And it's this very kind of, um, uh, brilliant, I- I don't know if it was intentional or not, it's sort of unintentional genius that they, that special operations has figured out that by sending people back into the cold over and over, it never really gets easier.

Dr. Wendy Suzuki 30:20 Uh-huh. Uh-huh.

Andrew Huberman 30:21 But over time, people actually start to crave it.

Dr. Wendy Suzuki 30:23 Yeah.

Andrew Huberman 30:23 And it provides this reduction in inflammation, et cetera.

Dr. Wendy Suzuki 30:26 Yeah.

Andrew Huberman 30:26 So anyway, beautiful practice. Thank you. I want to learn more about your tea meditation later in the episode.

Dr. Wendy Suzuki 30:31 Yeah.

Andrew Huberman 30:31 But, um, in any event, returning to w- ways that- that we can improve memory formation.

Dr. Wendy Suzuki 30:39 Yeah.

Andrew Huberman 30:40 Maybe, if you would-Tell us your story around this. I know you've told it before.

Dr. Wendy Suzuki 30:44 Mm-hmm.

Andrew Huberman 30:45 But I think a lot of members of the audience, and I, would love to hear, you know, how you came to this.

Dr. Wendy Suzuki 30:49 Yeah.

Andrew Huberman 30:49 Because growing up in neuroscience, I knew you as one of the, I would say, one of the three or four, and they're all alongside one another, not, um, this isn't a hierarchical statement. Three or four top memory researchers in the world, right? Textbook material is Suzuki, uh, in the, my textbooks are filled with the word Suzuki, your last name, according to the information on memory and memory formation. So you were doing that.

Dr. Wendy Suzuki 31:16 Mm-hmm.

Andrew Huberman 31:17 And doing the things that academics do.

Dr. Wendy Suzuki 31:19 Yeah.

Andrew Huberman 31:19 And then you're still doing that, but-

Dr. Wendy Suzuki 31:21 Yes.

Andrew Huberman 31:22 ... and still at a very high level, but then things took a different direction.

Dr. Wendy Suzuki 31:26 Yeah.

Andrew Huberman 31:26 Maybe we could talk about your story and how, um, you came to the place you are at now.

Dr. Wendy Suzuki 31:32 Yeah.

Andrew Huberman 31:32 Because I think it provides a number of tools that people could, um, implement themselves.

Dr. Wendy Suzuki 31:36 Yeah, yeah. So this story happened, um, as I was working to get tenure at NYU, and, and as you know, it's a, it's a stress-filled process. They give you six years to, you know, show your stuff, and you are judged in front of all your colleagues, and either they say, "Okay, you can join the club." Or they say, "Sorry, you are, you know, humiliated in front of everybody." This was going through my-

Andrew Huberman 32:01 They actually tell people to leave.

Dr. Wendy Suzuki 32:03 Yeah.

Andrew Huberman 32:03 If you don't get tenure, you're gone.

Dr. Wendy Suzuki 32:04 You, you have to leave your institution. And so, um, so, you know, you work really, really hard. And so my strategy was, um, I'm just going to not do anything but work, and I'm just going to work, and I'm, I'm going to, uh, just work as hard as I can for the six years. And, um, what happens when you work and you don't have any sort of life outside of work, and, um, you live in New York, where there's all sorts of really good takeout, you gain 25 pounds, which is exactly what I did. And you get really, really stressed, and you start to ask yourself, "How come I'm living in New York City, and I love Broadway, and I've never, I haven't gone to a Broadway show in two years?" Um, and so I, I, so I, I, 25 pounds overweight. I, um, I decided to go on vacation, and, uh, I went by myself 'cause I had no friends, and I went to, um, I, I did a adventure, um, river rafting trip in Peru. And so I go by myself and, you know, meet other interesting people, and, um, I, I was the weakest person on this whole trip. Like, I was, I, they were so much in better shape, it was embarrassing. And they won't say this, they won't admit this to me, but it was true. And I came back and I said, "Okay, I cannot be the weakest person. I'm in my late 30s, I have to do something." So I went to the gym and, um, I said, "Oh my God, I'm 25 pounds overweight. Let's, let's try at least to, uh, um, lose this weight." And so I go to the gym, um, I notice how much better I feel when I go to just a single class. I remember the very first class I went to was a hip-hop dance class. I'm a terrible hip-hop dancer, but I still felt good after, after that class. And then fast-forward a year and a half, I've lost the 25 pounds. So proud of myself. So much happier. And I'm sitting in my office doing what you and I do a lot, which is writing an NIH grant, which is our lifeblood, right? And, um, writing, writing, writing, and this thought goes through my mind that had never gone through my mind before, which was during this six years of gran- of frantic grant writing when I was trying to get tenure, and that thought was, "Grant writing went well today." You know, that, that felt good. I was like, "I've never had that thought before. What- what's going on here? This is really weird."

Andrew Huberman 34:27 I don't know that anyone has had that thought before.

Dr. Wendy Suzuki 34:29 (laughs) No, I'm sure people have had that thought. But, um, I thought maybe I'm just having a good day. Um, but when I thought about it, I thought it's, it's not just today. My grant writing seems to have been getting smoother. Like, I'm able to focus longer. It, the, the sessions feel, feel better to me. And, you know, at that point, the only thing that I changed in my life, it was a huge thing, but I had become a gym rat rather than a workaholic. And that's when my, you know, spidey sense for neuroscientists popped up and I said, "What do we know about the effects of exercise on your brain?" Um, because if I think about it, what was better about my writing is I could focus longer and deeper, very important, and I could remember those little details that you try and pull together for your million-dollar NIH grant from, you know, 30 different articles that you have open on your screen all at the same time. That's the hippocampal memory. I was studying that. I was writing the grants on, on hippocampal memory. And, uh, so that's when I got really interested in the effects of exercise on both prefrontal focus and attention function and hippocampal function, because of my own observation and this kind of, I still remember where, where I was sitting, which office I was in when I had this revelation. But the thing that really sealed it for me, that made me think not just, oh, this is interesting, but, "I, I want to study this," is right around that time, um, I got a phone call from my mom, um, who said that my dad wasn't feeling well and that he had, um, told her that he got lost driving back from the 7-Eleven, which is literally seven blocks from our house that I grew up in, and, um, I knew that was, that was hippocampal function. I suspected dementia. I suspected, though I didn't want to admit Alzheimer's dementia, which he, which he had. And, um, it was funny because... I mean, it wasn't funny, but, um, my mom and dad are two sides of, uh, a very different coin. My dad is the, the, uh, the engineer, not so active all his life, but would love to sit, sit and read books all day. My mom was the athlete. She, she played tennis, team tennis into her 80s.And, uh, and it, it started to show at, at that point.

Andrew Huberman 36:58 Mm-hmm.

Dr. Wendy Suzuki 36:59 And, uh, so then I had, then I had even a, a more pressing reason to think about what the effects of exercise were, because I noticed that all the things that were improving in my brain suddenly went away in my, my dad's brain. Really, really smart guy, engineer in Sil- you know, Silicon Valley, helped, helped that push in Silicon Valley in the '70s happen. He had no more memory. He couldn't focus his attention. His mood was rock bottom. He's a very happy guy, and everything was the opposite in me. And I started thinking, "This isn't just something to help, you know, somebody who wants to get tenure. Um, this is something that could help millions and millions of people, most importantly, our aging population. What if, you know, what's happening?" And so the thing that makes me wake up in the morning is when I realized that every single time you move your body, um, you are, um, releasing a whole bunch of neurochemicals. And some of 'em we've talked about, the, the good mood comes from dopamine and serotonin and noradrenaline. But the thing that gets released also, particularly with aerobic exercise, is a growth factor called, um, brain-derived neurotrophic factor or BDNF. And that is so important because what it does is it goes directly to your hippocampus and it helps brand new brain cells grow in your hippocampus. We all have that. Even if you're a couch potato, you can get new brain cells in your hippocampus to grow. But it's like giving your hippocampus a, um, a boost with this regular BDNF if you are exercising, which means that we all have the capacity to grow a bigger, fatter, fluffier hippocampus. And so what I like to give people is this image of every single time you move your body, it's like giving your brain this wonderful bubble bath of neurochemicals. What's going on? I, I need my bubble bath of noradrenaline and dopamine and serotonin and growth factors. And with regular bubble baths, what am I doing? I'm growing a big fat fluffy hippocampus. And I'm not gonna cure my father's dementia, Alzheimer's dementia, but you know what? If I go into my 70s with a big fat fluffy hippocampus, even if I had that in my genes and it starts to, uh, kick in, it's gonna take longer for that disease to start to affect my ability to form and retain new long-term memories for facts and events, which is my motivation for getting up and doing my 30 to 45 minutes of, of aerobic

Dr. Wendy Suzuki 39:35 exercise every day.

Andrew Huberman 39:36 Fantastic. Um, quick question about your protocol.

Dr. Wendy Suzuki 39:41 Yeah.

Andrew Huberman 39:41 Just because, uh, and then, uh, we'll, uh, discuss a few mechanistic things related to what signals the body might be sending the brain.

Dr. Wendy Suzuki 39:48 Mm-hmm.

Andrew Huberman 39:49 And a little bit more, uh, detail on, uh, BDNF and some circuitry.

Dr. Wendy Suzuki 39:54 Yeah.

Andrew Huberman 39:55 So you, 30 to 45 minutes of, it sounds like cardiovascular exercise might be special.

Dr. Wendy Suzuki 40:01 Yes.

Andrew Huberman 40:02 But as I say that, I, and I think about the literature that I'm aware of-

Dr. Wendy Suzuki 40:06 Mm-hmm.

Andrew Huberman 40:06 ... in mice and some in monkeys and certainly in humans, looking at the effects of exercise on brain function and typically the outcome is improvement, almost always.

Dr. Wendy Suzuki 40:15 Mm-hmm. Yeah.

Andrew Huberman 40:15 I don't think I've ever seen a paper showing that when animals or humans exercise more that their brain gets worse.

Dr. Wendy Suzuki 40:21 No.

Andrew Huberman 40:21 Um, I just can't think of a single paper.

Dr. Wendy Suzuki 40:24 Yeah.

Andrew Huberman 40:24 It doesn't mean it doesn't exist. I'm sure someone will put one in the comment section. (laughs)

Dr. Wendy Suzuki 40:27 (laughs)

Andrew Huberman 40:27 They'll find that one, and, and thank you for, if you can find that. But, um, but it seems like it's always cardiovascular exercise. And experimentally in a lab, it's a lot easier to get a mouse to run on a treadmill-

Dr. Wendy Suzuki 40:37 Yeah.

Andrew Huberman 40:38 ... than it is to get a mouse to lift weights, although people have put-

Dr. Wendy Suzuki 40:40 (laughs) Right.

Andrew Huberman 40:40 ... little ankle weights on mice and done-

Dr. Wendy Suzuki 40:41 Yes, yes.

Andrew Huberman 40:42 And the ways of getting mice to do resistance work is actually a little bit barbaric.

Dr. Wendy Suzuki 40:46 A little stressful.

Andrew Huberman 40:46 Because oftentimes they'll, they'll incapacitate a limb to overload another limb.

Dr. Wendy Suzuki 40:50 Yeah.

Andrew Huberman 40:50 So it's an asymmetric thing. It's not the sa- same as sending them in to do squats.

Dr. Wendy Suzuki 40:54 Right, right.

Andrew Huberman 40:54 Or deadlifts or something.

Dr. Wendy Suzuki 40:56 Yeah.

Andrew Huberman 40:56 So, um, but cardiovascular exercise might be special.

Dr. Wendy Suzuki 41:00 Yeah, yeah.

Andrew Huberman 41:01 What are your thoughts on that? And please first though, tell us your routine. Your routine is 30 to 45 minutes of, are you a Peloton cycler?

Dr. Wendy Suzuki 41:11 Yeah.

Andrew Huberman 41:11 Are you, does it matter?

Dr. Wendy Suzuki 41:12 Um, I think that, uh, the data suggests that as long as your heart rate is getting up for these long-term effects on your hippocampus and prefrontal cortex, you also, uh, um, get better at shifting and focusing your attention. Um, for that, you need cardiovascular. And what I use is, uh, a video workout that I started even before the pandemic. It's called Daily Burn, and it's just, you know, thousands of different workouts. But I love, they are 30 minutes that I sometimes add on a 10 to 15 minute stretch at the beginning or at the end. But, um, I love the variety. Sometimes I do it with weights, sometimes I do it without weights. Uh, uh, I love kickboxing, so they have a lot of kickboxing in there. It just fits my, um, fits my, fits my routine and it's always there and I don't have to get all dressed up to go to the gym to, uh, (laughs) to, to work out. So that's, that's what I do.

Andrew Huberman 42:05 And that's a daily thing, seven days a week?

Dr. Wendy Suzuki 42:07 Yeah. Yeah.

Andrew Huberman 42:07 Seven days a week. Fantastic. Um, so in terms of the, the way that some of these changes are, are being conveyed fr- from the body to the brain-

Dr. Wendy Suzuki 42:16 Yeah.

Andrew Huberman 42:16 ... that, that fascinates me.

Dr. Wendy Suzuki 42:17 Yeah.

Andrew Huberman 42:17 And I mean, as you and I know, and I'm, I'm sort of a repeating record on the, uh, podcast always saying, you know, you, it, you got a brain but you also have a spinal cord and then your nervous system connects everything.

Dr. Wendy Suzuki 42:27 Mm-hmm. Yeah.

Andrew Huberman 42:27 Every organ in your body is-

Dr. Wendy Suzuki 42:28 Right.

Andrew Huberman 42:28 ... basically signaled to by the nervous system and back to the nervous system. Your spleen, everything. But so l- let's imagine your morning routine, you, you do your cardiovascular exercise. Okay, so you're pumping more blood.

Dr. Wendy Suzuki 42:41 Mm-hmm.

Andrew Huberman 42:41 That's the definition of a higher heart rate. Stroke volume of the, of the, of the heart goes up over time.

Dr. Wendy Suzuki 42:46 Yeah.

Andrew Huberman 42:46 You're getting fitter. So blood flow to the brain is increasing.

Dr. Wendy Suzuki 42:49 Mm-hmm.

Andrew Huberman 42:49 Do we know...... how that gets translated to a signal to release more BDNF.

Dr. Wendy Suzuki 42:54 Mm. Yeah.

Andrew Huberman 42:55 You know, and then it raises this other question which is, does it matter where your mind is when you exercise?

Dr. Wendy Suzuki 43:00 Mm. Yeah.

Andrew Huberman 43:01 Because ultimately the brain, of course, you can anchor your attention to the exercise-

Dr. Wendy Suzuki 43:05 Mm-hmm.

Andrew Huberman 43:05 ... or you can be listening to a podcast-

Dr. Wendy Suzuki 43:06 Right.

Andrew Huberman 43:07 ... or something else. I've always wondered about this.

Dr. Wendy Suzuki 43:08 Yeah, yeah.

Andrew Huberman 43:09 You know, c- can we enhance the effects of exercise by combining the enhanced blood flow-

Dr. Wendy Suzuki 43:13 Mm-hmm.

Andrew Huberman 43:13 ... with cognitive work during exercise?

Dr. Wendy Suzuki 43:16 Yeah, yeah.

Andrew Huberman 43:16 Or is it simply a matter of just getting more blood flow up to the-

Dr. Wendy Suzuki 43:19 Mm-hmm.

Andrew Huberman 43:19 ... hippocampus?

Dr. Wendy Suzuki 43:19 Yeah. I wish I had the answer to that question too. My instinct is yes it matters, partially because of the work of your colleague, Alia Crum, on, on mindset and the power of that to change how physiologically our body is responding. So how could it not work in her experiments and, or work in her experiments and not work for my, my morning, or our morning, exercise routine? So but, but are there studies, point to a study? I don't know of one. So exercise, uh, uh, neuroscientists out there, I'd love to see, you know, that, that, that study done. Um, so yes, it works. Um, before I go into the aerobic thing, I always like to start with the least amount of exercise to get something really useful, because I don't want people to say, "Oh God, I hate, you know, sweating, I don't want to listen anymore." So, so I always like to start with, um, studies have shown that just 10 minutes of walking outside can shift your mood. That is part of that neurochemical bubble bath that you're getting: dopamine, serotonin, noradrenaline. Um, and 10 min- and anybody can walk for 10 minutes. Um, and so that is, uh, for all of you thinking that out there, what is the minimum that I could get some of these brain effects, 10 minutes of walking, anybody can do it.

Andrew Huberman 44:43 Uh, is outside important? I'm a big believer in getting photons-

Dr. Wendy Suzuki 44:46 Yeah, yeah.

Andrew Huberman 44:46 ... into the eyes.

Dr. Wendy Suzuki 44:47 It, um, I think that that study was done indoors on a treadmill, so, and, and the comparison wasn't done. But moving your w- uh, which is great. I, you know, some, in the middle of the pandemic, I walked around my apartment for 30 minutes sometimes just for some variety. Uh, felt like a rat on a running wheel, but, but, um, uh, yes. So, so that, that minimum amount of movement in your body can get you th- those mood effects. But what about the big, fat, fluffy hippocampus? What about the better performing prefrontal cortex? That's where you start to need the, the cardio, cardio workout. And from my reading of the literature, there haven't been enough studies, you know, um, uh, directly comparing and contrasting kickboxing with running with, um, whatever, whatever other cardio that you need to do. But any cardio workout that is done has these positive effects. So I'm gonna say, my interpretation of that is that whatever way you get your heart rate up, including a power walk, a power walk can get your heart rate up, that, that is beneficial. And what is happening, there are two pathways that have been studied about how you go from moving your body to more BDNF, that, that neurotrophin that's, uh, that's, um, increasing the growth of new hippocampal brain cells. The two pathways are the following. One is a myokine, which is a protein released by the muscles. So, and not your heart. These are striated muscles, um, in your body. And so by running, this, these were studies done in rats on running wheels, they showed that the running rats had, um, more of this myokine released, the myokine passed the blood-brain barrier, so it got into the, the, uh, rarefied, very protected bloodstream of inside the brain, and that myokine stimulated the release of BDNF in the brain. That's pathway number one. Pathway number two comes through the liver, uh, because exercise is a stress on, generally. Uh, how do we know that? Well, cortisol is released whenever we exercise. It, we, we need, we need, uh, that sugar, uh, in our blood, and so, so that's how the physiological, um, mechanisms work. And so, um, there is a, uh, ketone, um, uh, beta-hydroxybutyrate that we've known for a very long time that gets released by the liver during exercise, and we also know that that particular ketone passes that blood-brain barrier and it's another stimulant for BDNF. So kind of the final common pathway seems to be, um, BDNF stimulation in the hippocampus. Is it the only one? Probably not, but that's the one that has been studied most, most clearly. So it's, you know, it comes from all of our physiological systems. Our muscles working, our liver, um, responding to the stress of, of exercise, and what is it doing? It is making our, uh, uh, you know, giving more BDNF precursors to get into our brain to cause the up spike of BDNF, um, which is part of your bubble bath that you're getting every time you move.

Andrew Huberman 48:02 I love that description of a factor from muscle and a factor from liver, because any time we- we're thinking about movement of the body and translating that to the brain, uh, as you so clearly pointed out, that needs to be tr- it needs to traverse the blood-brain barrier.

Dr. Wendy Suzuki 48:18 Mm-hmm.

Andrew Huberman 48:18 Not everything that happens in the body is communicated to the brain.

Dr. Wendy Suzuki 48:21 Yeah.

Andrew Huberman 48:21 Uh, and these seem like really important signals. Um, beta-hydroxybutyrate, uh, you mentioned is a ketone. Uh, I just want to underscore, that doesn't mean, folks, that you need to be on a ketogenic diet. I think people hear ketone and they think it d- you know, I know some people are, most people are not, I imagine. Um, there are ketones that are released in your brain and body that can function even if you're, um, ingesting carbohydrates and not ketogenic-

Dr. Wendy Suzuki 48:46 (laughs)

Andrew Huberman 48:46 ... just for a point of clarification.

Andrew Huberman 48:48 Um-... this issue of new neurons.

Dr. Wendy Suzuki 48:51 Mm.

Andrew Huberman 48:52 Is one that you hear a lot.

Dr. Wendy Suzuki 48:53 Mm.

Andrew Huberman 48:53 You know, neurogenesis.

Dr. Wendy Suzuki 48:54 Yeah.

Andrew Huberman 48:54 You're going to grow more new neurons, new neurons, and, and my understanding is that the rodent literature is very clear.

Dr. Wendy Suzuki 49:01 Mm-hmm.

Andrew Huberman 49:01 That animals that run on wheels more often, um, it turns out rodents love to run on wheels.

Dr. Wendy Suzuki 49:05 Yes, yes.

Andrew Huberman 49:05 Do you know these studies by Hoppy Hofster which are pretty funny? Um, they're very cool-

Dr. Wendy Suzuki 49:09 (laughs)

Andrew Huberman 49:09 ... by the way, Hoppy, uh, Howard Hughes investigator.

Dr. Wendy Suzuki 49:11 (laughs)

Andrew Huberman 49:11 I'm, uh, not n- I'm not making light of them.

Dr. Wendy Suzuki 49:14 Yeah.

Andrew Huberman 49:14 If, they put running wheels in a field.

Dr. Wendy Suzuki 49:17 Uh-huh.

Andrew Huberman 49:17 And ro-

Dr. Wendy Suzuki 49:18 (laughs)

Andrew Huberman 49:18 Wild rodents will run to the running wheel and run on that running wheel.

Dr. Wendy Suzuki 49:22 Oh, that's great.

Andrew Huberman 49:22 So there's some, they really enjoy it.

Dr. Wendy Suzuki 49:24 Yeah, yeah.

Andrew Huberman 49:24 Which I find amusing-

Dr. Wendy Suzuki 49:25 Yeah.

Andrew Huberman 49:25 ... for reasons that probably only a neuroscientist-

Dr. Wendy Suzuki 49:27 L- right. (laughs)

Andrew Huberman 49:27 ... would find amusing. Um, in any case, in rodents, it seems that, uh, running more on a wheel can trigger neurogenesis.

Dr. Wendy Suzuki 49:36 Yes.

Andrew Huberman 49:36 Literally the, the, the birth of new neurons and the addition of new neurons to the hippocampus. In monkeys, this has been controversial. It seems it does happen in the hippocampus and in the olfactory bulb.

Dr. Wendy Suzuki 49:47 Mm-hmm. Yeah.

Andrew Huberman 49:48 Probably not in the neocortex.

Dr. Wendy Suzuki 49:49 Right.

Andrew Huberman 49:49 Thinking back to the decades or more-

Dr. Wendy Suzuki 49:52 Controversy, yeah.

Andrew Huberman 49:52 ... old controversy between Liz Gould and Pasko Rakic. I hope they settled their, their differences there, uh, neuroscientists love to argue.

Dr. Wendy Suzuki 49:59 (laughs) .

Andrew Huberman 49:59 Um, it's kind of what we do. Um, and in humans, I think it's been a bit controversial. Like some people say absolutely yes, other people say absolutely no there are new neurons added to the adult brain. I haven't followed that literature down-

Dr. Wendy Suzuki 50:15 Mm-hmm.

Andrew Huberman 50:15 ... to the detail.

Dr. Wendy Suzuki 50:16 Yeah.

Andrew Huberman 50:16 Um, but I do remember one study that I don't think is contested which is the work of Rusty Gage at the Salk Institute.

Dr. Wendy Suzuki 50:24 Mm-hmm.

Andrew Huberman 50:24 Where they actually injected a d- a sort of dye-type marker into the brains of terminally ill humans.

Dr. Wendy Suzuki 50:31 Yeah.

Andrew Huberman 50:31 Who very graciously offered to have their brains removed and dissected after death.

Dr. Wendy Suzuki 50:36 Mm-hmm. Yeah.

Andrew Huberman 50:37 And in these ver- in some cases very old-

Dr. Wendy Suzuki 50:40 Mm-hmm.

Andrew Huberman 50:40 ... terminally ill humans, they did see evidence for new neurons-

Dr. Wendy Suzuki 50:44 Yes.

Andrew Huberman 50:45 ... being born in the hippocampus.

Dr. Wendy Suzuki 50:46 Right.

Andrew Huberman 50:46 Can I s- trust that idea still? Is that, uh-

Dr. Wendy Suzuki 50:49 Uh-

Andrew Huberman 50:49 ... generally accepted?

Dr. Wendy Suzuki 50:50 Well, so after that study, which was quite a while ago, uh, there are more recent studies, still controversial, but, um, showing and demonstrating using even new and better techniques than were used in that, that original Rusty Gage study, which was groundbreaking at the time, that, um, that suggest and I think show that there are new neurons born in a a d- adult human brains into the ninth decade of life.

Andrew Huberman 51:19 Wow.

Dr. Wendy Suzuki 51:19 So they not only did this, I think those, those patients were in their 60s, then they, they died of cancer. Um, but, but these new studies, uh, looking across the timeline, can we see? Because the other thing was, yeah, maybe you have some when you're 20, but by the time you're older and you might need these new neurons, you have no new neuron growth. And so these studies seem to, uh, suggest that yes, yes you did, y- yes you do, and we all do, even into old age.

Andrew Huberman 51:48 Great.

Dr. Wendy Suzuki 51:48 So yeah.

Andrew Huberman 51:49 Great. And,

Andrew Huberman 51:50 um, I'll just take a moment to say that I am personally not aware of any studies looking at other forms of exercise besides cardiovascular exercise for sake of brain health. And this I think is an important, um, gap in the literature-

Dr. Wendy Suzuki 52:03 Mm-hmm.

Andrew Huberman 52:03 ... that ought to be filled, whether or not, for instance, high intensity interval training or whether or not weight training, um, which has other effects on the musculature. So you can imagine perhaps the myokine-

Dr. Wendy Suzuki 52:14 Right.

Andrew Huberman 52:14 ... to BDNF pathway, the pathway one that you mentioned might be signaled, but maybe not the liver pathway. Maybe, yes, I'm speculating here. Those studies need to be done.

Dr. Wendy Suzuki 52:22 Yeah.

Andrew Huberman 52:22 To my knowledge, they just haven't been done yet.

Dr. Wendy Suzuki 52:24 Yeah, yeah.

Andrew Huberman 52:24 Um, and but they should be done. If you would, could you tell us about some of the more specific effects of exercise on memory? You know, when memory's-

Dr. Wendy Suzuki 52:35 Yeah.

Andrew Huberman 52:35 ... a broad category of-

Dr. Wendy Suzuki 52:36 You're right.

Andrew Huberman 52:36 ... of, of effects-

Dr. Wendy Suzuki 52:37 Yeah.

Andrew Huberman 52:37 ... and phenomena. So things like, uh, what comes to mind is short-term, medium, and long-term memory, reaction time-

Dr. Wendy Suzuki 52:43 Mm-hmm.

Andrew Huberman 52:45 ... um, learning math, at least for me, is quite a bit different than, uh, learning history.

Dr. Wendy Suzuki 52:50 Mm-hmm.

Andrew Huberman 52:50 Um, although there's certainly overlap in the neural, neural underpinnings. Uh, what has been demonstrated in the laboratory-

Dr. Wendy Suzuki 52:57 Yeah.

Andrew Huberman 52:57 ... in animal models, but, but especially in humans?

Dr. Wendy Suzuki 52:59 Yeah, sure.

Andrew Huberman 53:00 And, and if you want to share with us any results from your-

Dr. Wendy Suzuki 53:03 Mm-hmm.

Andrew Huberman 53:03 ... your lab, uh, published or unpublished-

Dr. Wendy Suzuki 53:05 Yeah.

Andrew Huberman 53:05 ... I'm sure that the audience would be delighted to learn about them.

Dr. Wendy Suzuki 53:07 Absolutely. Let me start with, um, kind of the immediate effects, acute effects as they're called, of exercise on the brain. So this is asking, what does a one-off exercise session do for your brain? And there, um, uh, there are three major effects that have been reproduced. I've seen it in my lab. Many labs have reproduced this. So what do you get with a one-off... This is usually an aerobic type, type exercise session, 30, 30 to 45 minutes. What you get is that mood boost, very, very consistent. You get, um, uh, you get, uh, improved prefrontal function, typically, uh, tested with a Stroop, uh, test, which is a test that, uh, asks you to shift and focus your attention in specific ways. Um, it's a challenging task, and clearly dependent on the prefrontal cortex largely. And, um, significant improvements in reaction time, so your, your speed at responding, often a motor kind of, uh, but cognitive motor response is, is improved. Um, over the pandemic, one of the unpublished studies that I did looking at the effects of 30 minutes of age-appropriate workout, um, in subjects ranging in age from their 20s all the way up to their 90s. So what are the, um, the things that I saw most consistently? Irrespective of your age, everybody got a decreased anxiety and depression and a hostility score, which is very important, you know, so it's, it's not just decreasing your anxiety and depression, but decreasing your hostility levels-

Andrew Huberman 54:47 Making the world a better place.

Dr. Wendy Suzuki 54:48 ... in all this. Making the world a better, better place.... energy, the feeling of energy went up. And, um, what we found is in the older population, even more than in the younger population, we saw improved performance on both Stroop and, um, Erikson flanker task, which are, which is another task dependent on, um, really focusing in on different letters and paying attention to what letter is being shown. Um, so, so these are consistent e- effects. How long do they last? One of the studies that I did publish in my lab showed that the immediate effects of exercise lasted up to two hours. Unfortunately, that was the longest that we lasted, they were still there at two hours. Um, so that's, you know, that's, that's a pretty big bang for your buck.

Andrew Huberman 55:35 That is.

Dr. Wendy Suzuki 55:36 One 30-minute...

Andrew Huberman 55:37 Sorry to interrupt.

Dr. Wendy Suzuki 55:38 Yeah. Yeah.

Andrew Huberman 55:38 I just want to make sure I understand. So if when you say the effects lasted up to two hours, does that mean up to two hours after you finished exercise-

Dr. Wendy Suzuki 55:45 Yes.

Andrew Huberman 55:45 ... or up to two hours of memory-challenging, um, uh, work?

Dr. Wendy Suzuki 55:52 Ah.

Andrew Huberman 55:53 Y- yeah, just, just to be clear.

Dr. Wendy Suzuki 55:54 Yeah, that's a great question. So, um, my study looked at, uh, uh, two hours after you finish your workout, we gave you these cognitive tests. During that two-hour period, um, you were free to do anything except exercise or eat, and so th- there was no, no, uh, extra load on people. But two hours later, you did do significantly better on these, uh, focused attention tasks, um, compared to a, a group that, uh, watched videos for, for the exercise period. This was an hour of, um, cycling that they did. These were young, young subjects

Dr. Wendy Suzuki 56:31 in their 20s.

Andrew Huberman 56:31 Okay, so, um, if I finish my exercise at 9:00 AM-

Dr. Wendy Suzuki 56:36 Mm-hmm.

Andrew Huberman 56:37 ... even if I start this cognitive work, this mental work at 11:00, I'll still see benefits.

Dr. Wendy Suzuki 56:42 Yes.

Andrew Huberman 56:43 Right, so-

Dr. Wendy Suzuki 56:43 At least by 11:00, because I didn't go farther than two hours, so it could last even longer than that, but, but I have evidence that it lasts for two hours.

Andrew Huberman 56:51 And, and perhaps if I had started the cognitive work at 45 minutes after my exercise ended-

Dr. Wendy Suzuki 56:57 Mm-hmm.

Andrew Huberman 56:57 ... it would also be helpful?

Dr. Wendy Suzuki 56:58 Yes, I-

Andrew Huberman 56:59 So there's no reason to think-

Dr. Wendy Suzuki 57:00 ... yep.

Andrew Huberman 57:00 ... that there's a ch- that you have to wait before starting cognitive work.

Dr. Wendy Suzuki 57:02 Yeah, no reason at all.

Andrew Huberman 57:03 I'm asking questions of the sort that I get in the comments-

Dr. Wendy Suzuki 57:06 Okay, great.

Andrew Huberman 57:06 ... that we are going to get in the comment section.

Dr. Wendy Suzuki 57:07 Okay, great. (laughs)

Andrew Huberman 57:07 We always strive for clarity here. So what this tells me is that, um, exercising early in the day-

Dr. Wendy Suzuki 57:14 Mm-hmm.

Andrew Huberman 57:15 ... may have a special effect.

Dr. Wendy Suzuki 57:17 Right.

Andrew Huberman 57:17 Uh, I realize that some people cannot exercise until later in the evening.

Dr. Wendy Suzuki 57:21 Mm-hmm.

Andrew Huberman 57:21 But you mentioned something earlier that I want to cue people to, it's very, very important. I don't think I've ever mentioned this on the podcast, which is, any kind of physical activity will increase cortisol-

Dr. Wendy Suzuki 57:32 Mm-hmm.

Andrew Huberman 57:32 ... to varying degrees.

Dr. Wendy Suzuki 57:33 Yes.

Andrew Huberman 57:34 And so sometimes it's a healthy increase, sometimes it's an unhealthy increase. If you do two hours of really intense exercise and you're not prepared for it-

Dr. Wendy Suzuki 57:40 Yeah.

Andrew Huberman 57:40 ... that's a big spike in cortisol, probably not a good thing-

Dr. Wendy Suzuki 57:43 Yeah.

Andrew Huberman 57:44 ... for most people. But if you are going to do your cardiovascular or weight training later in the day-

Dr. Wendy Suzuki 57:49 Mm-hmm.

Andrew Huberman 57:50 ... that increase in cortisol can promote too much wakefulness for sleep, etc.

Dr. Wendy Suzuki 57:55 Yeah.

Andrew Huberman 57:55 Shifting that cortisol spike early in the day is associated with a number of important things related to mood, um, etc. But more and more what I'm thinking and hearing is that exercise early in the day is key. Our former dean of the medical school, Phil Pizzo-

Dr. Wendy Suzuki 58:09 Uh-huh.

Andrew Huberman 58:10 ... wa- was and is kind of famous still for, uh, jogging between the hours of, like, 4:00 and 5:00 AM-

Dr. Wendy Suzuki 58:16 Uh-huh.

Andrew Huberman 58:16 ... or 5:00 and 6:00, uh, and then running the medical school.

Dr. Wendy Suzuki 58:18 (laughs)

Andrew Huberman 58:19 So, um, and you're up early doing your exercise and cold shower-

Dr. Wendy Suzuki 58:23 Yeah.

Andrew Huberman 58:23 ... and meditation.

Dr. Wendy Suzuki 58:23 Yes.

Andrew Huberman 58:23 We'll talk about meditation.

Dr. Wendy Suzuki 58:25 Yeah.

Andrew Huberman 58:25 But this is more and more of a push, I, I feel like, or, or a, um, a stimulus for us to think about moving our exercise earlier in the day.

Dr. Wendy Suzuki 58:33 Yeah, I mean, I like to say that, you know, I, I know there, there are moms and dads out there and they just say, "Look, I have a kid that the kid's more important than my doing my exercise." So you will get benefits if you, if you do it whenever, whenever you can. So that's great. More power to you. But what all the neuroscience data suggests is the best time to do your exercise is right before you need to use your brain in the most important way that you need to use it every day. And so that is why the morning, for most of us, is beneficial. That's why I do it in the morning, and I'm lucky enough to be able to do that. Uh, um, but yeah, it, it, it makes sense with all, everything we know about how, how this works and how it benefits our brain.

Andrew Huberman 59:20 I think about our colleague, um, Eric Kandel-

Dr. Wendy Suzuki 59:23 Mm-hmm.

Andrew Huberman 59:23 ... who not incidentally has a Nobel Prize and studies memory and-

Dr. Wendy Suzuki 59:27 Yep.

Andrew Huberman 59:27 ... and, um, rumor has it that he's been a, uh, a swimmer for a lot of years-

Dr. Wendy Suzuki 59:32 Yeah.

Andrew Huberman 59:32 ... that he'll put in, I think nowadays he's in his 90s now, um, he'll put in half a mile, but he used to d- swim a mile a day or something of that sort.

Dr. Wendy Suzuki 59:41 Wow. I, I heard that too, that he was a swimmer and he does it very, very religiously.

Andrew Huberman 59:44 Okay, so there, there are a few other neuroscientists that do that. I can think of a lot of neuroscientists that probably should exercise more, and I don't say that to poke at them. I just would love to see them doing their incredible work for many more decades.

Dr. Wendy Suzuki 59:54 Yes.

Andrew Huberman 59:55 And everything that we're talking about today indicates that if one doesn't-

Dr. Wendy Suzuki 59:58 Yeah.

Andrew Huberman 59:59 ... unless you have incredible genetics-

Dr. Wendy Suzuki 1:00:01 Yeah.

Andrew Huberman 1:00:02 ... we all experience age-related dementia.

Dr. Wendy Suzuki 1:00:04 Mm-hmm.

Andrew Huberman 1:00:04 Right? I mean, the story of your father is a, is a, a salient one, um, and we should remember that as we go forward. But I also want to emphasize, I'd love to get your thoughts on just memory and memory loss in general.

Dr. Wendy Suzuki 1:00:17 Yeah.

Andrew Huberman 1:00:17 It seems we all get worse at-

Dr. Wendy Suzuki 1:00:19 Right.

Andrew Huberman 1:00:20 ... remembering and learning things.

Dr. Wendy Suzuki 1:00:21 Mm-hmm.

Andrew Huberman 1:00:22 Even if we don't get Alzheimer's-

Dr. Wendy Suzuki 1:00:23 Yeah.

Andrew Huberman 1:00:24 ... when does that typically start for, for humans?

Dr. Wendy Suzuki 1:00:27 You know, I think there's so much variability, um, n- not only because we are individuals, but because our stress levels are different and, um, well, everybody's anxiety level has gone up, uh, in the last, in the last couple of years, but that also has an effect. We, we don't remember as much in a highly stressful, highly anxious-... situation. So, so, you know, as you know, it's hard to answer that question. People say, "Okay, just tell me how much exercise I have to do." Okay, just-

Andrew Huberman 1:00:59 30 to 40 minutes a, a day.

Dr. Wendy Suzuki 1:01:00 Yeah. (laughs)

Andrew Huberman 1:01:00 But, but I love the per day. You know, I've been doing this whole thing of telling people, "Oh, the data say 150 to 200 minutes of zone two cardio," which is kind of, you know-

Dr. Wendy Suzuki 1:01:10 Yeah.

Andrew Huberman 1:01:10 ... moderately hard, but not-

Dr. Wendy Suzuki 1:01:11 Yeah.

Andrew Huberman 1:01:11 ... excessively hard. Um, but I love this everyday theme.

Dr. Wendy Suzuki 1:01:15 Yeah.

Andrew Huberman 1:01:16 Because what- whenever I do that, the questions that come back are, "Well, what if I take a long hike on the weekends?" And so people start negotiating.

Dr. Wendy Suzuki 1:01:22 (laughs) Right.

Andrew Huberman 1:01:22 There's something that's very powerful about non-negotiable everydays.

Dr. Wendy Suzuki 1:01:25 Yes.

Andrew Huberman 1:01:25 Sun in your eyes every day, even through cloud cover.

Dr. Wendy Suzuki 1:01:27 Right.

Andrew Huberman 1:01:27 Exercise for 30, 45 minutes.

Dr. Wendy Suzuki 1:01:29 Yeah.

Andrew Huberman 1:01:29 Cold shower every day.

Dr. Wendy Suzuki 1:01:30 Every day, yeah.

Andrew Huberman 1:01:33 You know, um, I, you know, my understanding of the literature is that somewhere in our 50s or 60s, we start noticing little hiccups in memory.

Dr. Wendy Suzuki 1:01:41 Mm-hmm, yeah.

Andrew Huberman 1:01:42 Um, for some people younger, for some people later.

Dr. Wendy Suzuki 1:01:45 Yeah.

Andrew Huberman 1:01:46 But I have to imagine that doing the exercise throughout one's entire life is going to help offset some of this, simply 'cause you're-

Dr. Wendy Suzuki 1:01:53 Absolutely.

Andrew Huberman 1:01:54 ... the BDNF and other-

Dr. Wendy Suzuki 1:01:55 Yeah.

Andrew Huberman 1:01:55 ... downstream effects.

Dr. Wendy Suzuki 1:01:56 Yeah, yeah, I mean, that's, that's what it suggests. One of my favorite studies, and then I want to get back to, um, you wanted, you invited me to share some of my unpublished data-

Andrew Huberman 1:02:06 Yes, absolutely.

Dr. Wendy Suzuki 1:02:06 ... on the effects of long-term exercise. But first I want to share, uh, one of my favorite studies, which is a longitudinal study, um, done in Swedish women, and this was published in 2018. And, uh, what they did was back in the 1960s, they found, um, Swedish women, 300 Swe- Swedish women in their 40s and they characterized them as low fit, mid fit, high fit, okay? And then 40 years later, they came back and found these women, they let them do, live their lives, and they asked what happened to these women as a function of whether they were low fit, mid fit, high fit in their 40s. They're now in their 80s. Um, and what they found was that, um, relative to the low fit or mid fit women, the women that were high fit gained nine more years of good cognition later in life. Now, this is not a randomized controlled study, um, this is a correlational study, but does it agree with everything that we've been talking about today? Yes. Does it agree with this idea that, you know, the women that were high fit were giving their brains this, this bubble bath, you know, maybe not every day, but very, very regularly for that entire 40 years, and that built up their big, fat, beautiful hippocampi? Yes, it does. So, um, that's one of my favorite studies.

Andrew Huberman 1:03:31 Yeah. Another, um, cause for getting the exercise in consistently.

Dr. Wendy Suzuki 1:03:37 Yes.

Andrew Huberman 1:03:37 Yeah, and there's no... I am impressed by this 10-minute walk and the improvements in mood-

Dr. Wendy Suzuki 1:03:43 Yes.

Andrew Huberman 1:03:44 ... from just a 10-minute walk.

Dr. Wendy Suzuki 1:03:45 Yeah.

Andrew Huberman 1:03:45 But again, I, I think that daily repetition also, I have to imagine, has effects on the very pathways that allow plasticity. This is something we, in the realm of neuroplasticity, we don't often hear about or think about, even as neuroscientists, which is that the pathways for engaging plasticity probably c- probably, I'm speculating here-

Dr. Wendy Suzuki 1:04:07 Mm-hmm.

Andrew Huberman 1:04:07 ... can be made better by engaging in the sorts of behavior this- that stimulate plasticity.

Dr. Wendy Suzuki 1:04:12 Yeah, yeah.

Andrew Huberman 1:04:12 In other words, if one gets better at calming themselves down-

Dr. Wendy Suzuki 1:04:14 Mm-hmm.

Andrew Huberman 1:04:14 ... under stress, those circuits get better at doing that, right?

Dr. Wendy Suzuki 1:04:18 Yes, absolutely.

Andrew Huberman 1:04:18 Neural circuits gain proficiency.

Dr. Wendy Suzuki 1:04:20 Yeah.

Andrew Huberman 1:04:20 And so because blood vessels can grow, capillaries can grow in the brain, you can imagine that more pumping of blood to the brain, delivery of these, uh, various muscle and liver factors would also establish larger or more efficient portals to getting that stuff there.

Dr. Wendy Suzuki 1:04:39 Yeah, yeah.

Andrew Huberman 1:04:39 So you could imagine a kind of an amplifying effect of, of exercise.

Dr. Wendy Suzuki 1:04:43 Mm-hmm, absolutely.

Andrew Huberman 1:04:43 And again, I'm speculating here, but I- I've seen this over and over again in colleagues, the ones who exercise consistently-

Dr. Wendy Suzuki 1:04:49 Yeah.

Andrew Huberman 1:04:50 ... seem to be really, really smart and doing amazing work well into their 80s and 90s.

Dr. Wendy Suzuki 1:04:54 Uh-huh.

Andrew Huberman 1:04:55 And the ones who aren't, some of whom actually pride themselves on how little they exercise-

Dr. Wendy Suzuki 1:05:00 Yeah.

Andrew Huberman 1:05:01 ... um, they get worse over time.

Dr. Wendy Suzuki 1:05:02 Mm-hmm.

Andrew Huberman 1:05:03 You see them each meeting, each decade, and I'm not poking fun at them at all, it's actually quite, quite hard to see.

Dr. Wendy Suzuki 1:05:08 Yeah.

Andrew Huberman 1:05:08 And they're kind of a fading light, they're starting to flicker.

Dr. Wendy Suzuki 1:05:11 Mm-hmm, yeah.

Andrew Huberman 1:05:12 Um, so there is this incredible relationship between body vitality and brain vitality.

Dr. Wendy Suzuki 1:05:16 Yeah.

Andrew Huberman 1:05:16 Um, that is, of course, is not an excuse for spending all day in the gym.

Dr. Wendy Suzuki 1:05:20 Right.

Andrew Huberman 1:05:20 Right? The gym rats, uh, you know... (laughs)

Dr. Wendy Suzuki 1:05:23 (laughs)

Andrew Huberman 1:05:23 I enjoy working out, so I could imagine doing that, but, um, but that doesn't make us smarter, unfortunately. You actually have to do the cognitive work also, right?

Dr. Wendy Suzuki 1:05:31 Yes, yes, right.

Andrew Huberman 1:05:31 It's not just exercise.

Dr. Wendy Suzuki 1:05:32 Right, right.

Andrew Huberman 1:05:33 So I'd love to hear about some of these new unpublished data.

Dr. Wendy Suzuki 1:05:35 Yeah, yeah. Okay, so when I jumped into the exercise work, um, everybody was studying people 65 or older because that's when cognitive decline begins, and if the idea is exercise can help you with your cognition, then makes sense. However, I thought, well, you know, that it's great, there's lots of work there. I wanted to know what happens in people in their 40s and their 50s, maybe even their, their 30s and their 20s. Why? Because that's when we as humans are able, ready, wi- willing and able to increase our exercise and, um, gets us set, set up to, you know, build our brains as we go into our 60s. And so, um, the first study that I did looked at low fit participants from their 30s to mid 50s. And we wanted to ask this question, you know, how much exercise do you really need to start seeing benefits? Do you see benefits or maybe you have to wait until you start seeing cognitive decline to get benefits? That was one of the, the theories out there. And so that's what I wanted to do, and so what we did was three months of two to three times a week-... cardio. It was a spin, spin class, so, you know, spin classes are great for cardio. And the, the comparison group was two to three times a week of competitive video Scrabble. So no heart rate, uh, change, but, but they had to come into my lab and, and be in a group, just like they were in a group for the, uh, for the, um, um, spin class. Uh, we tested them cognitively, cognitively at the beginning and the end of the session. What we found was two to three times a week of cardio, in these people, they're a low fit, which means, specifically, that they were exercising less than 30 minutes a week for the three months previous to the experiment. So they went from that to two to three times a week of spin class. And what we found was, um, changes in baseline rates of their positive mood states went up relative to the video Scrabble group. Um, their, uh, body image got more positive because they were exercising, which is great, and really important, their motivation to exercise went up significantly compared to the video Scrabble group, which is, which is great. So the more you exercise, the more motivated you are to exercise. What about cognition? What changed in the cognitive circuits of their brain? Number one, we got improved performance on the Stroop task. But, uh, we're headed towards my favorite structure, which is the hippocampus. What we found was improved performance on both a recognition memory task, which was a, um, a memory encoding task. Um, and, uh, that is can you, uh, can you differentiate, uh, similar items that we're asking you to remember? And an spatial episodic memory task where we had them play one of those Doom-like games when they went into this spatial maze, and they had to do things in a virtual city. Their performance there got better, which is very, very classically dependent on the hippocampus. So, so this I... It was so satisfying to a- to do this study, because, um, uh, I've been wanting to answer this question. What is a minimum amount or doable amount of exercise that will get you these cognitive benefits? And now I can say, in 30 to 50 year olds that are low fit, two to three times a week. Is that doable? Absolutely. Will it be hard if you're low fit? Yeah, it's, it's gonna be challenging, but absolutely doable. And so, you know, that, that is, uh, it makes sense with all of the, all of the, um, mechanisms that we are... I didn't study the mechanisms, just to be clear, but with all the mechanisms we are imagining are playing a role here, that absolutely makes sense, and, and it is doable. This is not like you have to become marathon runner to get any of these benefits. This is you have to start moving your body on a regular basis, two to three times a week, and I, so I, I love that for its realness.

Andrew Huberman 1:09:54 Mm-hmm. How long are those sessions again?

Dr. Wendy Suzuki 1:09:56 45 minutes.

Andrew Huberman 1:09:57 45 minutes.

Dr. Wendy Suzuki 1:09:57 Yeah, 45 minutes. Uh, it, it's a typical spin, uh, spin kind of class. There's a warmup for five minutes and a cooldown for five minutes, so it's really, uh, 30 f- 35 minutes, 35 minutes of, you know, they, they're-

Andrew Huberman 1:10:11 Work.

Dr. Wendy Suzuki 1:10:11 ... really pushing you, yeah.

Andrew Huberman 1:10:12 So, and so they're breathing reasonably hard. Heart rate-

Dr. Wendy Suzuki 1:10:15 Yeah.

Andrew Huberman 1:10:15 Heart rate is up.

Dr. Wendy Suzuki 1:10:16 Heart rate is definitely-

Andrew Huberman 1:10:17 Heart rate is up.

Dr. Wendy Suzuki 1:10:18 ... up, yeah, yeah.

Andrew Huberman 1:10:18 Yeah. The, I find the, the, uh, all of those results are really interesting. The, the result showing improvement in motivation to exercise-

Dr. Wendy Suzuki 1:10:27 Yeah.

Andrew Huberman 1:10:28 ... is interesting 'cause it gets back to this issue of kind of a self-amplifying effect.

Dr. Wendy Suzuki 1:10:31 Yeah, right.

Andrew Huberman 1:10:32 And, um, the neuroscientist in me wants to, uh, think about kind of premotor circuits and the fact that-

Dr. Wendy Suzuki 1:10:38 Mm.

Andrew Huberman 1:10:39 ... you know, we have a motor system that can obviously do things like lift cups and walk and run if we want to or need to.

Dr. Wendy Suzuki 1:10:45 Mm-hmm.

Andrew Huberman 1:10:45 But that, um, it's possible to create a kind of anticipatory, uh, activity-

Dr. Wendy Suzuki 1:10:50 Yeah.

Andrew Huberman 1:10:51 ... in our nervous system, where-

Dr. Wendy Suzuki 1:10:52 Right.

Andrew Huberman 1:10:52 ... our body then craves a certain stimulus.

Dr. Wendy Suzuki 1:10:55 Mm-hmm.

Andrew Huberman 1:10:55 You mentioned the cold and how you-

Dr. Wendy Suzuki 1:10:56 Yes.

Andrew Huberman 1:10:56 ... crave the cold.

Dr. Wendy Suzuki 1:10:57 Yeah.

Andrew Huberman 1:10:57 Now whether or not that's the adrenaline and the dopamine-

Dr. Wendy Suzuki 1:11:00 Mm-hmm.

Andrew Huberman 1:11:00 ... et cetera, or whether or not, um, somebody who exercises started going from zero, less than 30 minutes per week to two to three times a week, four, th- 45 minutes, as you're, you described for this study.

Dr. Wendy Suzuki 1:11:11 Mm-hmm.

Andrew Huberman 1:11:12 Y- I've had that experience before of if I'm jo- the, the cardio that's I tend to battle the most, and I, my, I love lifting heavy objects-

Dr. Wendy Suzuki 1:11:21 Uh-huh. (laughs)

Andrew Huberman 1:11:22 ... um, at least heavy for me. I, I'm happy to go to the gym every other day-

Dr. Wendy Suzuki 1:11:25 Mm-hmm.

Andrew Huberman 1:11:26 ... and just lift heavy objects for an hour. It just makes me happy. I like the way it feels.

Dr. Wendy Suzuki 1:11:29 Yeah.

Andrew Huberman 1:11:29 And, um, I've been doing it since I was in my teens, so 30 years. Cardio's a little bit trickier. I like to run.

Dr. Wendy Suzuki 1:11:35 Mm-hmm.

Andrew Huberman 1:11:35 But if I stop running for a little while-

Dr. Wendy Suzuki 1:11:37 Mm.

Andrew Huberman 1:11:38 ... I find it very hard to get back into.

Dr. Wendy Suzuki 1:11:39 Yeah, yeah.

Andrew Huberman 1:11:40 But if I start running three times a week-

Dr. Wendy Suzuki 1:11:42 Uh-huh.

Andrew Huberman 1:11:42 ... for 30 to 45 minutes-

Dr. Wendy Suzuki 1:11:43 Yeah.

Andrew Huberman 1:11:43 ... and I do this pretty consistently on the days I don't weight train, I find that I start to crave it. It's almost as if my body needs that in order to, I always say clear out the cobwebs.

Dr. Wendy Suzuki 1:11:53 Mm.

Andrew Huberman 1:11:53 But it's like my mind doesn't function as well. Clearly now-

Dr. Wendy Suzuki 1:11:56 Yeah.

Andrew Huberman 1:11:56 ... I understand why, um, and why exercise helps. But also my, uh, physically, I almost feel like my body needs to engage in that movement.

Dr. Wendy Suzuki 1:12:04 Mm.

Andrew Huberman 1:12:04 Like the premotor circuits are-

Dr. Wendy Suzuki 1:12:05 Mm-hmm.

Andrew Huberman 1:12:05 ... are kinda revving.

Dr. Wendy Suzuki 1:12:06 Yeah.

Andrew Huberman 1:12:06 Kinda like revving the engine on your car while it's in park.

Dr. Wendy Suzuki 1:12:09 Yeah, yeah, yeah.

Andrew Huberman 1:12:10 Um, so the motivation to exercise obviously could be multifaceted. It could be purely psychological. But do you think there's

Andrew Huberman 1:12:17 any reason to speculate at least or believe that we can c- build an anticipatory resi- reverberatory activity-

Dr. Wendy Suzuki 1:12:25 Mm.

Andrew Huberman 1:12:25 ... into our nervous system?

Dr. Wendy Suzuki 1:12:26 Yeah, yeah. You know, I, I agree with that because I also have those same kinds of thoughts, and, and I do have anticipatory exercise when I, I can't do it. So I just got back from a week and week and a half in Paris where I got to do a book launch of, of my last book, Good Anxiety. And, um, I, I, I really, I walked around a lot, but I did not do my exercise for that whole week and a half, and, um-... but there was a lot of stress because I had to all these interviews in French, so I gave myself a break. Oh-

Andrew Huberman 1:13:03 Do you speak French?

Dr. Wendy Suzuki 1:13:04 I speak French, yes.

Andrew Huberman 1:13:04 I was going to say, otherwise, it would be really stressful.

Dr. Wendy Suzuki 1:13:05 Yeah, that- that would be really stressful. (laughs)

Andrew Huberman 1:13:07 I'm- Now- Then I'd be really impressed. Th- then I would definitely start exercising.

Dr. Wendy Suzuki 1:13:11 (laughs)

Andrew Huberman 1:13:11 I would- Actually, I would follow your m- morning routine to a T, but-

Dr. Wendy Suzuki 1:13:14 (laughs)

Andrew Huberman 1:13:14 Okay, very impressive, nonetheless.

Dr. Wendy Suzuki 1:13:16 S- So-

Andrew Huberman 1:13:16 Yeah.

Dr. Wendy Suzuki 1:13:16 But I got back and- and, you know, coming back this direction from- from Paris, I- I live in New York, is, um, is much easier and so I was able to get- get up at a normal time the next day, and that exercise session that first day is like, okay, I'm back in my home, I'm back in my environment, and it felt so good. It was like I wanted to come back. And, um, and I know it's because I- I worked up over years. Now, I could truthfully say seven days a week, but it was, you know, first it was four to five, then it was five to six, and, um, yeah, seven, i- but that includes a yoga day or sometimes I have to do it for 10 minutes instead of 30 because I have to leave. But- but that habit of you do that, even for five minutes, you do either the- the- the wait 10 minute thing or five minute thing or- or a stretch, um, that is a, uh, tiny habit. Wh- Is that somebody at Stanford that invented this idea of tiny habits?

Andrew Huberman 1:14:17 There are a couple of-

Dr. Wendy Suzuki 1:14:18 I thought it was.

Andrew Huberman 1:14:18 The- Well, we've got like a number of people there. There's, um, and I'm- I apologize in advance to all the people I neglect in this statement, um, but I'm happy to put it in the comments, folks. Um, BJ Fogg is there, has done-

Dr. Wendy Suzuki 1:14:30 Yes.

Andrew Huberman 1:14:30 And-

Dr. Wendy Suzuki 1:14:31 That's who I-

Andrew Huberman 1:14:31 Yeah.

Dr. Wendy Suzuki 1:14:32 I-

Andrew Huberman 1:14:32 Yeah, BJ's done really-

Dr. Wendy Suzuki 1:14:33 Yeah.

Andrew Huberman 1:14:33 ... uh, great work. And then, um, James Clear wrote a book-

Dr. Wendy Suzuki 1:14:37 Mm.

Andrew Huberman 1:14:37 ... about habits and, uh, has- has a very popular newsletter about habits.

Dr. Wendy Suzuki 1:14:40 Yeah.

Andrew Huberman 1:14:40 We've done an episode about habits that covers some of their, uh, work and- and some of the- the more laboratory-ish-

Dr. Wendy Suzuki 1:14:46 Yeah.

Andrew Huberman 1:14:47 ... not ish, laboratory science, peer-reviewed work on it.

Dr. Wendy Suzuki 1:14:49 Yes.

Andrew Huberman 1:14:50 Daily behaviors, also daily behaviors performed at roughly the same time of day.

Dr. Wendy Suzuki 1:14:55 Yes. Yeah,

Narrator 1:14:55 very powerful.

Andrew Huberman 1:14:55 I mean, one thing we know for sure is that s- the circadian system is part of our nervous system's way of anticipating when things will happen-

Dr. Wendy Suzuki 1:15:03 Yeah.

Andrew Huberman 1:15:04 ... not just what will happen. I'm telling you things you obviously-

Dr. Wendy Suzuki 1:15:06 Mm-hmm. Yeah.

Andrew Huberman 1:15:07 ... know already. But for the audience, performing-

Dr. Wendy Suzuki 1:15:10 Yeah.

Andrew Huberman 1:15:10 ... your exercise at roughly the same time each day-

Dr. Wendy Suzuki 1:15:12 Mm-hmm.

Andrew Huberman 1:15:12 ... will make it easier.

Dr. Wendy Suzuki 1:15:13 Yes, absolutely.

Andrew Huberman 1:15:14 As opposed to just saying I'm going to do it seven days a week sometime today.

Dr. Wendy Suzuki 1:15:16 Right, that is hard.

Andrew Huberman 1:15:17 But, of course, getting it done sometime is better than not getting it done.

Dr. Wendy Suzuki 1:15:20 Yes, absolutely.

Andrew Huberman 1:15:21 Yeah, yeah.

Dr. Wendy Suzuki 1:15:21 Absolutely.

Andrew Huberman 1:15:22 Well, th- those are impressive effects and I love that you're starting to look in populations that are a bit younger, not because-

Dr. Wendy Suzuki 1:15:28 Yeah.

Andrew Huberman 1:15:28 ... some of these, um, older populations aren't important, but I think that building good habits in- across one's entire life-

Dr. Wendy Suzuki 1:15:36 Right.

Andrew Huberman 1:15:36 ... is really what it's about.

Dr. Wendy Suzuki 1:15:37 Right.

Andrew Huberman 1:15:37 Y- As I always say, with anything related to longevity or offsetting an age-related decline-

Dr. Wendy Suzuki 1:15:44 Mm-hmm.

Andrew Huberman 1:15:45 ... we don't know- it's hard to know if things work because-

Dr. Wendy Suzuki 1:15:47 Right.

Andrew Huberman 1:15:48 ... there's no within subject control.

Dr. Wendy Suzuki 1:15:50 Mm-hmm.

Andrew Huberman 1:15:50 But what we also know for sure is that you don't want to be the control experiment.

Dr. Wendy Suzuki 1:15:54 Right. (laughs)

Andrew Huberman 1:15:54 (laughs)

Dr. Wendy Suzuki 1:15:55 Exactly.

Andrew Huberman 1:15:55 You absolutely don't want to be the control experiment, especially for something that's purely behavioral. I mean, you're not talking about ingesting a particular supplement, you're not talking about changing your diet in any way. But I am curious-

Dr. Wendy Suzuki 1:16:07 Mm-hmm.

Andrew Huberman 1:16:08 ... do you, you know, diet is a very barbed wire topic on the- on the internet, um, which diets, whether or not they work, et cetera. But in general, did- in any of these studies, do they evaluate whether or not people change their eating habits when they start to exercise more?

Dr. Wendy Suzuki 1:16:23 Yeah. Um, I think I've seen one study that- that controlled for that. But, (laughs) I feel for them because it's hard enough to get people to exercise at the level and- and at the time and, you know, that you- you need for your study. If you also ask them, "Okay, fill out this survey to tell us exactly what you ate all day," they're going to say, "Forget- (laughs) forget you. I'm not- (laughs) I'm not joining your study." So, um, it's a critical question and, um, um, again, there's only been one that I've seen, and- and the evidence was that- that diets got better when they, you know, less processed foods, when- when they did adhere to this exercise. But a lot more information needs to be gathered in that- in that realm. The second

Dr. Wendy Suzuki 1:17:09 study that I wanted to share, unpublished, we're- we're writing it up right now, is, um, part two of that study that I just described, which was the low fit people. Next, we moved to mid fit people, like, "What about us? You know, we're already exercising. Wh- how- how- am I going to benefit from increasing my exercise?" So here again, we collaborated with a great, um, spin studio that had a whole bunch of mid fit people that- that by our definition were exercising, um, two to three times a week on a regular basis. That's great. All you people out there that are doing that, you should know you're already benefiting your brain. But our question was, what if we invited them to exercise as much as they wanted at the spin studio for three months, from, you know, two to three times all the way up to seven times a week, and let's just see what happened? And the control group, um, we asked them not to change their exercise. Um, and so what we ended up with was a nice big array of starting with mid fit people that exercised between staying at two to three times a week all the way up to seven times a week, and the bottom line from that study is every drop of sweat counted. That is, the more you change and you increase your workout up to seven times a week, the better your mood was. You had lower, um, uh, lower amounts of depression and anxiety, higher amounts of good, um, uh, good affect, and the better your hippocampal memory was with the more you worked out. Again, this was for three months. So I love that too because it gives power to- to those of us that are, you know, regularly exercising and wondering, "Do I really need to? I mean, is it really going to help me?" And the answer is yes. I mean, not all of us can exercise, go- go to a spin class seven times a week. But, um, I love the message that-... our body is responsive to that. And, and you can get better hippocampal function, better overall baseline mood affect with, with a higher level. So it works for, uh, the MidFit, uh, people as well.

Andrew Huberman 1:19:20 Fantastic. The, the more I, I learn from you, the more I'm starting to conceptualize the brain as an organ that is privileged in so many ways. You know, it has this unique blood-brain barrier.

Dr. Wendy Suzuki 1:19:30 Yeah.

Andrew Huberman 1:19:30 Um, has this incredible quality of being able to predict things, and its job mainly is, of course, to predict things, a- among, among other functions, of course. But that our brain isn't necessarily going to stay stable or get better over time, that it needs a signal.

Dr. Wendy Suzuki 1:19:48 Mm-hmm. Yeah.

Andrew Huberman 1:19:49 It, that it isn't sufficient to just say that we can't take it for granted, that, that our brain is actually an organ that n- requires a signal-

Dr. Wendy Suzuki 1:19:58 Mm-hmm.

Andrew Huberman 1:19:58 ... in order to maintain its own function.

Dr. Wendy Suzuki 1:20:00 Yeah.

Andrew Huberman 1:20:01 And it sounds like enhanced blood flow in these pathways that you described earlier, these two pathways, um, are at least a- among the more critical signals. Um, I'm tempted now to move my frequency of cardiovascular exercise from, I confess it's about three days, 35 minutes lately, and it should be more, uh, to daily. There's something really, again, really special about daily.

Dr. Wendy Suzuki 1:20:24 Yeah.

Andrew Huberman 1:20:24 Because it's nonnegotiable.

Dr. Wendy Suzuki 1:20:25 Right.

Andrew Huberman 1:20:25 You just do it.

Dr. Wendy Suzuki 1:20:26 Right.

Andrew Huberman 1:20:26 Um, and it sounds like if one were to do higher intensity exercise-

Dr. Wendy Suzuki 1:20:31 Mm-hmm.

Andrew Huberman 1:20:31 ... you know, in a spin class, I've never taken a spin class, but I've seen there are times when they're standing up on the bike and pedaling very hard.

Dr. Wendy Suzuki 1:20:37 Yeah. Yeah.

Andrew Huberman 1:20:37 So th- that is included in these kinds of workouts, right?

Dr. Wendy Suzuki 1:20:39 Absolutely, yeah.

Andrew Huberman 1:20:40 Okay.

Dr. Wendy Suzuki 1:20:40 I mean, that's what the instructor is doing.

Andrew Huberman 1:20:43 (laughs)

Dr. Wendy Suzuki 1:20:43 I cannot control.

Andrew Huberman 1:20:45 Right.

Dr. Wendy Suzuki 1:20:45 Uh, we did m- monitor heart rate, uh, o- of all the subjects and it was clearly, you know, (laughs) compared to the video Scrabble, it was (laughs) highly significantly different.

Andrew Huberman 1:20:54 Yeah, I would hope so.

Dr. Wendy Suzuki 1:20:54 Yes.

Andrew Huberman 1:20:55 I guess it depends on how intense that game of Scrabble is, but.

Dr. Wendy Suzuki 1:20:57 (laughs)

Andrew Huberman 1:20:58 Um, could we just briefly talk about, uh, mindset and affirmations?

Dr. Wendy Suzuki 1:21:04 Yeah, sure.

Andrew Huberman 1:21:04 Uh, you've talked a bit, um, before about, uh, affirmations, and as you mentioned the, uh, the beautiful work of my colleague at Stanford, Alia Crum-

Dr. Wendy Suzuki 1:21:13 Mm-hmm.

Andrew Huberman 1:21:13 ... um, and who, uh, we can summarize her work pretty simply, although we won't