Pete Wright:
Here’s something I catch myself thinking almost every session at the gym. I’ve got some sort of a heavy thing in my hands. I’m some number of reps in. And somewhere in the back of my head is this assumption that my brain has the hour off, that the body’s clocked in and the brain’s clocked out. But as I’m coming to learn, that’s backwards. Something is deciding which fibers to fire and in what order, and how hard to brace, and how much to tell the muscles on the other side to get out of the way. None of that’s happening in my hamstrings. Same body. What gets better is the wiring. So that’s today. We spend a lot of time on the show on what lifting does below the neck.

What about above it? There’s some research here connecting strength to memory and how sharp you are at 80. Some of it’s surprising, some of it’s maybe a little shaky. We’re going to talk about which is which. Srdjan brought the outline. I brought probably a healthy sense of doubt. We’ll see. This is Build for Health.

Hey, are you ready for this? This is really good. I said, what do you want to talk about?

Srdjan Injac:
Yes, it is.

Pete Wright:
You said we’re doing brain function and resistance training.

Srdjan Injac:
Yeah, I talk to my clients about that all the time.

Pete Wright:
All right, do tell. What do you talk about?

Srdjan Injac:
We don’t really talk about what exercise may be doing for the brain nearly as much as we probably should.

Pete Wright:
Yeah.

Srdjan Injac:
So every time you exercise, you’re not just asking your muscle to do the work. Your brain is involved in controlling those movements, and balance, coordination, concentration, decision making, learning how to do these things.

Pete Wright:
Yeah.

Srdjan Injac:
And over time, regular exercise can actually influence how well our brain functions and how it ages. And it’s important, because we spend a lot of time talking about protecting our heart and maintaining muscles and keeping our bones strong as we get older. But what good is having a strong body if you’re ignoring the health of the organ that’s controlling everything? Memory, attention, problem solving, all that stuff.

Pete Wright:
Yeah.

Srdjan Injac:
All of that depends on the brain. And one of the really exciting areas of exercise research is looking at whether physical activity, including resistance training, can help us maintain those abilities as we age. Your brain is involved in literally every repetition you do.

Pete Wright:
Yeah. It’s like crossword puzzles and Sudoku for your biceps.

Srdjan Injac:
Yeah. I mean, when you perform a squat, your muscles don’t simply decide to contract on their own. Your brain sends these electrical signals through your nervous system, telling specific muscles when to contract, how strongly to contract, and in what sequence. At the same time, information is constantly traveling back toward your brain, telling you where your body is positioned, how much force you’re producing, and whether you’re balanced. So that’s why lifting weights is actually a neurological activity as much as it is a muscular activity.

Think about learning a new exercise. The first time somebody performs a squat or a deadlift, it can look really awkward, even if they’re relatively strong. Several weeks later, the movement becomes smoother and more natural. Their muscles may have gotten stronger, but their nervous system also got better at performing the movement.

And this is why I always tell my clients, when I give them the exercise and they perform it, don’t think you’re going to get it right the first time. You’re not. It’s just not going to happen. This is a new movement for your body, for your brain, everything.

Pete Wright:
Yeah.

Srdjan Injac:
You’re trying to figure out and process all this information that I’m giving you, and you’re not going to get it right. I did it thousands of times, and every time I do it, I feel like I can perfect it more. And I keep thinking about the movement. That’s where I talk to people about the mind-body connection.

As long as you do it, and you do it again, and we repeat it over and over again, you get better.

Pete Wright:
Do it again.

Srdjan Injac:
It becomes like a muscle memory. You just do it. It’s like a reflex. So they’re like, well, I didn’t do it right. And I’m like, that’s okay. That’s fine. We’ll do it again. So it’s important for people to know: if they do something and they didn’t get it right, don’t stop.

Pete Wright:
So…

Srdjan Injac:
Do it again.

Pete Wright:
Yeah.

Srdjan Injac:
Try it again. Focus each time on different things. I give so many cues on this one exercise, and they’re like, oh my God, which one should I think about? And then you think about one, and then the other one kind of breaks down, and the form breaks down, and you’re like, oh my God, I’ve got to think about this one. So one thing at a time, and you’ll get there.

Pete Wright:
That is, and we’ll talk about other stuff, not just me, I promise, but that is one of the things that I think I suffer from. There are exercises I hate, and I hate them because I’m not good at them. There are exercises that are really hard…

Srdjan Injac:
Yes.

Pete Wright:
…but I don’t mind them, because I can do them. It’s the ones where my brain actually gets in the way. Or I should say it’s probably not my brain getting in the way. It’s probably some ego or something that’s in the way, that has a mental image of what I look like doing the exercise and what’s going on inside. I’m probably hurting myself because I’m doing it wrong, and I just want to resist. The walls go up. It is hard to get over the hump of being able to get good at the exercise.

Srdjan Injac:
I mean, when you do that, your brain becomes better at recruiting these motor units, basically activating the muscle fibers needed to produce the force.

Pete Wright:
Yeah.

Srdjan Injac:
So coordination between different muscles improves. Your technique becomes better, and your brain learns those movements. That’s why I said strength isn’t simply determined by how much muscle somebody has. Strength is partly a skill. You’re teaching your nervous system how to produce force efficiently.

Pete Wright:
Yeah.

Srdjan Injac:
So it’s also brain, not just your muscles. And one of the other benefits is that exercise increases the blood flow to the brain.

During exercise, your cardiovascular system has to work harder to deliver oxygen and nutrients through the body. But blood flow changes not only in your working muscle but also in your brain. Your brain requires a tremendous amount of energy for its size, and healthy circulation is important for maintaining that brain function. So regular exercise improves cardiovascular health, things like blood pressure, blood vessel function, glucose regulation, and all of those things matter to brain health as well. The brain isn’t living separately from the rest of your body.

Pete Wright:
Yeah.

Srdjan Injac:
Conditions that damage your blood vessels can eventually affect the blood vessels supplying your brain. So exercise improves not just cardiovascular and metabolic health. Some of those benefits can indirectly help protect the brain too.

Pete Wright:
Lifting, I think, as a cognitive task. We’ve talked before about executive function. We’ve talked about the idea of metacognitive processes, thinking about thinking. And this is sort of metaphysical activity: thinking about the activity. Talk about lifting as a cognitive task.

Srdjan Injac:
Yeah, one area researchers are particularly interested in is executive function. That is basically your brain’s management system. It includes abilities like planning, focusing your attention, controlling impulses, switching between tasks, solving problems, holding information in your mind while you’re using it. So, for example, following a recipe while you’re cooking, maybe planning your day…

Pete Wright:
Yeah.

Srdjan Injac:
…concentrating during a meeting, remembering instructions while completing a task, or making a decision when several things are happening at once. All of those involve executive function. Those abilities become extremely important as we age, because losing them can interfere with independence long before somebody loses physical strength. But research suggests that regular exercise can support executive function, and resistance training has shown benefits in several studies involving older adults. Memory and learning as well.

Pete Wright:
Yeah, yeah, yeah.

Srdjan Injac:
It’s been studied for its effects on things like memory and learning.

The hippocampus, the area of the brain heavily involved in forming and retaining memories, is also one of the areas that researchers pay close attention to when studying aging and dementia. Physical activity appears capable of influencing processes that support…

Pete Wright:
Yeah.

Srdjan Injac:
…its health. And again, aerobic exercise has a particularly large body of research here, but resistance training is increasingly part of the conversation as well. So it’s very important.

Pete Wright:
That was an interesting thing. I found that too. It seems like runners wholly love this area of research.

Srdjan Injac:
Yeah, yes.

Pete Wright:
The runners are high on this research because of the effects of aerobic exercise.

Srdjan Injac:
Yeah.

Pete Wright:
But I think this is the point, that strength training, resistance training, can actually have the same impact. What I don’t know, and what I couldn’t find, and I don’t know if you have any experience with this in particular in the gym, but does it matter what kind…

Srdjan Injac:
Mm-hmm.

Pete Wright:
…of resistance training you’re doing? Is a well-programmed lifting session on machines, where you have fewer choices of what your body can do, more or less useful than doing everything on free weights, where you’re bringing to bear a lot of different structures around balance?

Srdjan Injac:
It doesn’t matter, as long as it’s resistance training. It can involve both of them.

Pete Wright:
Okay.

Srdjan Injac:
It’s not just particularly the free weights or the machines. I mean both.

Pete Wright:
You started talking about aging in particular, the aging brain, and how resistance training impacts the aging brain. Was there more to that that I interrupted?

Srdjan Injac:
Some changes in brain function are normal with aging. Processing speed can slow down. Learning something new may take longer. Certain types of memory may not be as sharp as they were when we were younger. But there’s also a difference between normal aging and disease. Just like we shouldn’t assume becoming physically weak is an unavoidable part of getting older, we shouldn’t assume there’s nothing we can do to support our brain health. Age is obviously something we can’t change, and genetics are something we definitely can’t change.

But physical activity, blood pressure, blood sugar, things like smoking, sleeping, social activity, and several other lifestyle factors are things that we can actually influence with exercise. So exercise just gives us one more tool…

Pete Wright:
Yeah, yeah.

Srdjan Injac:
…to help us as we age.

Pete Wright:
Yeah.

Srdjan Injac:
Of course, it’s not going to change everything. There are some things we don’t have control over and can’t change, but there’s a lot of stuff that we do have control over, and exercise will definitely help. It’s a really important part that people don’t really think about when it comes to their brain, and how big a role exercise can have in influencing their brain.

Pete Wright:
There’s an interesting study that I stumbled across that I wanted to share with you, because I think it’s really great for adults aged 55 and over.

Srdjan Injac:
Uh-huh.

Pete Wright:
It was the SMART trial. And this is important, because you’re leaning in toward this age group and I want you to be ready.

Srdjan Injac:
Okay.

Pete Wright:
A hundred adults aged 55 and over with mild cognitive impairment. Randomized, double-blind, double-sham trial. Six months of high-intensity progressive resistance training, with or without computerized brain training. And the resistance training significantly improved the primary cognitive outcome at 18 months. And this is what was most interesting to me. The resistance training group alone outperformed the group that did resistance training and computerized brain training for executive function. There were people who were doing bespoke brain training for executive function who did worse than the people who didn’t, but only did heavy resistance training, in that age group.

Srdjan Injac:
Interesting.

Pete Wright:
That’s interesting, right? I think that’s fascinating.

Srdjan Injac:
Yeah.

Pete Wright:
There was a follow-up analysis that found gains in strength, not gains in aerobic capacity (sorry, runners), statistically mediated the cognitive improvement. It is the single best support for this guidance about get in the gym, lift heavy things. The strength gains are not just muscle gains.

Srdjan Injac:
That’s true. That’s pretty good.

Pete Wright:
That’s pretty good. Somebody put that research on a poster. Put it outside the gym.

I’m sure people will be lining up. Tell me more about the 55-plus crowd.

Srdjan Injac:
I’m not there yet.

Pete Wright:
I’m not there yet.

Srdjan Injac:
That’s how we got…

Pete Wright:
All right. Let’s see. We also have some issues with strength, balance, and independence. This is obviously another one that deals with folks who are aging. And this is one where I think we already sort of led into this: the more you work out, the more you challenge your body to do hard things that involve new moves, the better your overall performance is going to be. And that includes in the gym and getting up out of bed in the morning.

Srdjan Injac:
Yeah. Imagine somebody in their seventies or eighties whose brain is relatively healthy, but whose body has become extremely weak. They can’t easily get out of a chair. They’re afraid of falling. They can’t carry groceries. Walking upstairs is difficult. It’s different. The world almost becomes smaller.

Pete Wright:
Yeah.

Srdjan Injac:
They stop going places, seeing people, doing activities they enjoy. So physical weakness can indirectly affect emotional health, because it reduces independence and engagement with life. But maintaining that strength helps people continue interacting with their environment. That’s why strength is important. But resistance training can also improve, when appropriately programmed, balance and coordination, and a lot of that comes from the brain.

So falls become increasingly important as we age. A fall in your twenties might not leave you completely out, but a serious fall in your seventies or eighties can completely change your life. You recover from a fall when you’re in your twenties. Later, it’s a little bit harder.

Pete Wright:
Yeah.

Srdjan Injac:
Your nervous system plays a huge role in balance. Your brain is constantly receiving information from your eyes, your muscles, and your joints, and makes these tiny corrections to keep you upright.

Pete Wright:
Yeah, yeah.

Srdjan Injac:
So exercises that challenge appropriate levels of strength, stability, and coordination can help maintain those abilities.

So again, we’re training the nervous system and muscles together. You need both.

Pete Wright:
Yeah. Let me ask you a practical training question. By extension, what is doing more to keep you upright if you’re about to fall? Raw leg strength, or leg strength in combination with the speed of the correction you’re making in your brain when you stumble?

Srdjan Injac:
Exactly.

Pete Wright:
It is everything.

Srdjan Injac:
Yeah, it’s everything together.

Pete Wright:
So how do you train toward that correction? What does training look like for somebody who’s 65 years old and has a worry about being a fall risk? Do you train toward that?

Srdjan Injac:
Well, yeah. I have to not just train the muscles to become stronger, which of course is important, but I have to look at all his stabilizer muscles and…

Pete Wright:
Yeah.

Srdjan Injac:
…kind of test his reflexes and his concentration and focus, and how he balances, and challenge that. So he’s training his nervous system at the same time. I try to teach him that mind-body connection.

Because like I said, it’s not always in the strength of the muscle, but the nervous system as well.

Pete Wright:
Yeah.

Srdjan Injac:
There are different kinds of training that we do, depending on what level you come in with. But you will have to work on both. Not just that, but also strengthen the muscle, and then also work on flexibility.

So you have to work on everything. You can’t just focus on one thing.

Pete Wright:
Yeah, yeah.

Srdjan Injac:
But yeah, there are different things that are still safe, and I make sure that I challenge the balance. Sometimes they’ll get off balance and try to fall, and they’ll catch themselves, and stuff like that. But if you constantly keep doing that, like I said, repeating something over and over and over again, I’ve seen people get so much better at it. There was one guy I remember at the gym. We were just doing lunges, I think, and he tried, and he just could not stop. He lost his balance and just fell down on the ground. So he was kind of embarrassed. And I’m like, oops.

Pete Wright:
I feel like you’re talking about me.

Srdjan Injac:
It was a slow fall.

It was like, almost there, and then to go up and straight down.

Pete Wright:
Yeah.

Srdjan Injac:
So he was kind of embarrassed. I’m like, all right, we’ll work on it. And after about three months or something like that, I got him to do that same exact thing, and he did it with no problem.

Pete Wright:
Yeah.

Srdjan Injac:
Like he’d been doing it for years. And he was like, oh my God, I did not fall this time.

Pete Wright:
Yeah.

Srdjan Injac:
I’m like, no, because we did all this stuff to help you get to that point. And there was a lot of stuff that we would repeat. We’d do it over and over and over again.

Pete Wright:
Oh.

Srdjan Injac:
And then he would catch himself even when he was doing it wrong.

It was like a reflex. I wouldn’t even have to say anything. He would just correct himself right away, fix it. He can feel it.

Pete Wright:
Fix it, yeah.

Srdjan Injac:
And he knows. It’s almost like a reflex. The brain was telling him right away, sending the message, like, hey. And he was able to get way better, and then we were able to do so much other stuff, so many other things.

Because the whole time it was like, I can’t do those. I just can’t do those. I’ll probably never be able to do those, and I’m okay with that.

And I’m like, no, don’t accept that. I’m like, no, you can do that.

Pete Wright:
Yeah.

Srdjan Injac:
Like I always say, aging is inevitable, but weakness is not.

Pete Wright:
Yeah, yeah.

Srdjan Injac:
So I refuse to take that for an answer. He’s like, I can’t do that.

Pete Wright:
I can do that one.

Srdjan Injac:
I’m like, yes, you can.

Pete Wright:
Yeah.

Srdjan Injac:
Let’s work on it. And then, yeah.

Pete Wright:
I’ll tell you, man, Medicare data reported, this is a few years ago, that among 2.45 million older adults with a traumatic injury, 10.6 percent of those who fell were diagnosed with dementia within a year. Falls were associated with a 21 percent increased risk of a subsequent dementia diagnosis compared with other injury mechanisms. And the authors of this JAMA article explicitly describe falls and dementia as a two-way street. Dementia leads to falls, falls lead to dementia. And all of this is stuff that resistance training impacts. It makes you more agile, more responsive, more able to correct and save yourself from falls. And that’s really at any age. Any age.

Srdjan Injac:
Yeah.

Pete Wright:
Yeah.

Srdjan Injac:
Yeah, I mean, this is the thing. You have to be careful with…

Pete Wright:
Yeah.

Srdjan Injac:
…the way we say it, because resistance training won’t guarantee that someone won’t develop dementia.

Pete Wright:
Right, for sure.

Srdjan Injac:
And we shouldn’t tell people that lifting weights prevents Alzheimer’s disease.

Pete Wright:
No.

Srdjan Injac:
But what we can say is that regular physical activity is associated with better cognitive health and a lower risk of cognitive decline and dementia. So researchers are also studying resistance training specifically as a way to support cognitive function in older adults.

Pete Wright:
So why might it help?

Srdjan Injac:
Why might it help? There probably isn’t one single reason, but exercise improves cardiovascular health. It can improve blood pressure and blood sugar control. It can reduce physical inactivity. It can influence inflammation and growth factors, and it challenges the nervous system. It helps preserve muscle and physical independence. So all those things may contribute to maintaining a healthier brain. But like I said, it does not guarantee that someone won’t develop dementia.

Pete Wright:
Right, right. But if there’s a checklist of things you can do that are good for you…

Srdjan Injac:
Exactly.

Pete Wright:
Right.

Srdjan Injac:
Yeah. That would be one of them.

Pete Wright:
This is on it.

Srdjan Injac:
Exactly. Definitely. I definitely do it.

Pete Wright:
Yeah.

Srdjan Injac:
I’m noticing kind of that thing with my parents, so I’m trying to get them into the gym.

Pete Wright:
Yeah.

Srdjan Injac:
This is one thing that I do have control over…

Pete Wright:
Yeah.

Srdjan Injac:
…and there’s something that you can actually do about it.

Pete Wright:
Right.

Srdjan Injac:
This is like the medicine that you don’t need a prescription for.

Pete Wright:
Yeah. Yeah. All right. Well, I’ll tell you, I think about this stuff all the time, especially this week as we’re recording this episode. I think about all the exercises in the gym I say I hate and don’t want to do. Maybe I should just be a little bit more open, because it’s good for my brain. It’s good for my wiring. It’s good for the whole thing. Okay.

I hear it. I hear it. Thanks as always, Srdjan. Thank you for hanging out. Thank you, everybody, for downloading and listening to this show. We sure appreciate your time and attention. Don’t forget, send us your questions for the coach. We’ll answer them in an upcoming Q&A episode. And don’t forget to subscribe and share.

This is how we grow stronger together. Thanks for listening to Build for Health. We’ll catch you next week in the gym.