How to Exercise For Improved Cognitive Function | Dr. Tommy Wood & Dr. Andrew Huberman

Exercise & Cognitive Arousal

00:00Exercise in particular, we know very well that some period of exercise, it can be resistance training, aerobic exercise, very brief sprints, increase arousal, improve cognitive function across multiple domains, um improve learning um and retrieval, right?

00:13So, so you're definitely augmenting some of these processes of neuroplasticity. Some of that's going to be related to the catakolamines and other things that get released as you know as you as arousal increases. But we also know that different types of exercise have different effects on different parts of the brain.

00:31So yes, I think some of just like the general process of moving your body um and exerting effort definitely increases arousal. Um definitely improves cognitive function, improves learning as long as it's not truly exhaustive exercise. Like anybody who's done some terrible CrossFit WAD or you know I used to be a rower.

00:53We used to do a 2k test on the rowing machine, right? You do a 2k test on a rowing machine, your brain does not work afterwards. It's like a sixinute flat out like V2 max kind of level of exertion. Yeah, thanks. I'm going to interrupt briefly.

01:06Thank you for pointing that out because I think that people assume they have an infinite amount of energy and there's crossover and um I certainly have done, you know, extra sets to failure in a great morning workout and then the in the afternoon I'm dragging.

01:22If I hold back just a little bit in terms of volume, I find I get a real boost out of training. And I do low low volume high intensity, you know, usually two sets per exercise to, you know, two or three exercises per per muscle, like quadriceps being one muscle or something like that.

01:40If I do three, it's a small addition, right? The rest of the day, I'm kind of dragging. So, leaving something in the tank, yeah, does seem worthwhile. Not during the sets, but leaving something in the tank in terms of volume really seems to help, especially if you want your like to perform hard cognitive work directly afterwards.

01:58sometimes if you're trying to really push sure performance or adaptation right it's worth digging into that hole but it really just depends on what you want to be able to do directly afterwards I think student athletes especially in D1 schools they really um come to appreciate this I've had a few of them in my courses over the years and um they really understand when they're pushing very very being pushed very hard in their sport and um they know that they have to sit in the front of the classroom, sit upright, do ex take extra measures to make sure they're not dozing

02:33off, attention drifting, especially in the age of phones and iPads and and things like that. It's very very difficult. Um, yeah, thank you for for mentioning that because they're just an extreme case of the rest of us. You know, we're told we're all very busy like, "Oh, you need to exercise.

02:46It'll help your brain." And people like, "Well, I exercise and I'm exhausted." You know, that's not helping my brain. Let's get practical here. So, is there any way uh to it's got to be really subjective and uh depend dayto day. Is is there any way to kind of formalize that like should you train let's say resistance training or running?

03:07You know, should you cap it at an hour? Should you pull back on the intensity if you have harder cognitive work to do in the afternoon? We all want the maximum effect of exercise, but we don't want it to undercut our efforts. Yeah. I I think that a lot of it's going to be based on what your current capacity is, right?

03:22As as with

Optimal Workouts for Immediate Focus

03:24everything. So if you're you you want to do some you got some you know learning to do you got an exam you want to do some hard cognitive work at you know whatever it is writing a presentation analyzing data you uh reading you reading papers writing your book then [snorts] doing some kind of workout that's that's probably below your kind of typical or below what what you would do when you're really sort of pushing pushing the envelope.

03:49I think that when you look at meta analyses of exercise and then cognitive function immediately afterwards, the the protocol that has like the best evidence for it is like a 20 to 30 minute jog, right? So like that's the kind of um level of activity that that really seems to sort of like support all those general processes of plasticity and learning.

04:13What do you think is going on? Because it can't be that much arousal. I mean that the amount of catakolamines released from again catakolamines folks being the you know adrenaline norepinephrine and uh dopamine um generally increased levels arousal alertness uh propensity to move you just that's that I feel better people often think about the runner's high and endorphins the endorphins come from pretty long intense duration effort they're more of a you're floating kind of like you know I think the catakolamines are really the the cocktail of like all right I got a

04:43great workout in this morning showered got dressed I'm off to work. Let's go. That's the So 20 or 30 minute jog, I don't expect you'd get that much catakolamine release. I mean, you'll definitely get some, right? And like cortisol, too, right?

04:57Which obviously increases alertness and arousal and can can in the short term make you feel good. It's a good thing. Um, you you see similar effects of, you know, short resistance training workouts. Um, I think of it, it's it's probably a little bit of like an area under the curve thing because you see some similar effects of like you go out and you do six-second really hard sprints like max effort sprints.

05:18You do that a few times with a long break in between, right? That seems to have a similar effect, but you're only working for very short periods with very long rest periods. So, it's some it's something in that in that sphere. And I think it that's probably just it.

05:32It's just enough to you just kind of boost catamines a little bit, a little bit of cortisol. That's enough to kind of move you up the arousal curve to the point where you're then able to focus and engage a little bit better. I think yeah you don't need a huge dump of that um in order to achieve that increase in arousal particularly as it pertains to like learning and then you know cognitive performance in like formal cognitive tests when which is where this is usually done.

05:56If you're then thinking about the type of exercise that changes cognitive function or brain structure long term, effort uh and intensity do seem to matter a lot more. But those studies have looked less of well how did that how do they feel directly afterwards?

06:13Right now you're

Driving Long-Term Brain Growth

06:15thinking about what's the kind of stimulus that drives change over time and then intensity matters a lot as well. So um the the best example um is with aerobic exercise on the kind of uh zone 2 up to kind of zone 4 five sprint spectrum. So most people who listen to your show have probably familiar with a study where in older adults they had them do uh brisk walking three times a week 40 minutes.

06:43Um, and when you kind of read the study and and the heart rate uh levels they were trying to attain, it was basically zone 2 work. 40 minutes brisk walking three times a week for a year. And they saw significant increases in the volume of the hippocampus uh increases in V2 max fitness, increases in circulating BDNF levels, though circulating BDNF doesn't actually get into the brain, but it's kind of telling you something about probably BDNF that's being produced in the brain.

07:10um and improvements in memory. With all of that, however, there's a much more recent study that took again older adults and randomized them across three different groups. One was like a low inensity group. Another group basically did kind of zone 2 type work on a treadmill three times a week, very sim similar to that previous study that I mentioned.

07:32And the

Norwegian 4x4 Protocol

07:34third group did um a high-intensity interval training intervention, which is the Norwegian 4x4 protocol. So 4 minutes at 85 to 95% of maximum heart rate, they had a 3minut rest in their protocol. They did that four times over. That's really hard.

07:48Anybody who's done the Norwegian 4x4, if I then say, well, hey, do that three times a week for 6 months. Like that's that's three times a week. Three times a week for 6 months. That's that's pretty intense. But what they showed was that that high-intensity interval training group, they improved their fitness just as well as the zone 2 group, interestingly, but they had much better improvements in hypocample function and maintenance of hypocample structural and MRI scan.

08:13And they maintained that benefit for 5 years after the six-month intervention. So they worked really hard um for 6 months, but that that benefit was maintained for for a really long period of time. And in several analyses within that study, they basically show that the harder people worked um and the more cortisol they released, the better the benefit.

08:36And so this is important because nowadays there's or you know there's several people out there saying, "Oh, don't do high intensity exercise. It releases cortisol. That's stressful. Your body can't handle it." Right? This study directly shows that working really hard, releasing a lot of cortisol in high-intensity interval training actually improves hippocample structure and function um over over time.

08:55So yes, I imagine after they did their workouts, their brain wasn't maybe working at its best cuz that's a hard workout. But over time, this was this really strong stimulus that then resulted in significant improvements. Forgive me if you said it and I missed it.

09:12Uh what was the form of exercise? Was it rowing or biking or It was on a treadmill. Treadmill. Yeah. Uh really interesting. Um and you said it about 85% of max heart rate. Yeah. So that's that's a typical Norwegian 4x4 protocol, but I don't think that's the protocol you have to

How Lactate Supports Neuroplasticity

09:28do. I think it's just this process of highintensity exercise that you releases a whole bunch of myines and lactate in particular. We know that lactate very easily gets into the brain, generate, you know, stimulates BDNF production as as kind of part of that support of neuroplasticity or augmenting recent neuroplastic processes.

09:47I think there's something about that just that high intensity work that drives some of those factors that then support structure and function. [music]