HSOS #38: Move Your Body, Save Your Brain: How Exercise Protects Your Brain from Dementia (Part 2)

Your brain is literally begging you to move, and in this episode, Kim delivers the science behind why in the most compelling, relatable way possible. Picking up right where Episode 37 left off, she digs into the powerful research connecting exercise to a dramatically lower risk of dementia and Alzheimer's, and breaks down exactly what is happening inside your body when you sweat, lift, and even just take a walk around the block. From a little something called "Miracle-Gro for your brain" to why Alzheimer's is being called Type 3 Diabetes by some researchers, this episode will have you lacing up your sneakers before it's even over. Consider this your science-backed permission slip to move your body like your brain depends on it, because it actually does.

Let's talk.

Welcome to Her Season of Strength, where women over 40 reclaim their bodies, their energy, and their voices, without apologies. I'm Kim Duffy, registered dietitian, personal trainer, mom, and your biggest hype woman when it comes to aging like you mean it.

This show isn't about chasing skinny or counting wrinkles. It's about building real strength: physical, emotional, and hormonal. Each week, I'll share straight-talking nutrition tips, sustainable fitness strategies, and conversations that help you feel powerful in your skin once again.

Menopause is not an ending, it is only the beginning. This is your season of strength.

What I Cover in This Episode:

• Why physical inactivity is one of the top 12 modifiable risk factors for dementia and what that actually means for you
• The remarkable finding that aerobic exercise can reverse age-related brain shrinkage by one to two years
• What BDNF is and why researchers consider it to be "Miracle-Gro" for your brain
• The surprising reason some scientists are calling Alzheimer's "Type 3 Diabetes" and how exercise fights it
• How strength training releases brain-protective proteins from your muscles that travel directly to your brain
• Why the years between 40 and 65 are a critical window for building a "savings account" for your brain
• The one thing that even regular exercisers are doing that still independently raises their risk of cognitive decline
• What a realistic, brain-protective movement week actually looks like for women over 40
• How combining last week's episode (#Feed Your Brain: The MIND Diet and Menopause) with this week's exercise strategies creates the most powerful one-two punch against dementia
• Email me at info@strengthinnutrition.com with which program interests you: BRAIN, HEART or BONE (you can also say NONE or ALL 😉)

If you would like to read any of the reference I cited in this episode, please email me at info

Links & resources for this episode:

Fit After 50+ Program: 8-Week Nutrition Coaching & Strength Program for menopausal women.  Join the interest list today for the best discounts, bonuses and updates about the next program coming Fall of 2026!

Free cheat sheet: "20 Tips to Crushing Menopause"

Join my free weekly newsletter list and get a new high protein recipe sent to your inbox every Thursday. 

Find me on social media: Instagram I Facebook I Tiktok

Transcript

[00:00:00] Hi there, and welcome to Her Season of Strength, where women over 40 reclaim their bodies, their energy, and their voices, without apologies. I'm Kim Duffy, registered dietitian, personal trainer, mom, and your biggest hype woman. When it comes to aging like you mean it, this show isn't about chasing skinny or counting wrinkles.

[00:00:20] It's about building real strength, physical, emotional, and hormonal. Each week, I'll share straight talking, nutrition tips, sustainable fitness strategies. And conversations that help you feel powerful in your skin. Once again, menopause isn't an ending. It's only the beginning. This is your season of strength.

[00:00:39] Hey. Welcome back to Her Season of Strength. Thank you so much again for taking a second out of your day to listen in. So today's episode is one I've been looking forward to since I wrapped up last week's episode. So if you didn't catch last week's episode, it was number 37. I want you to go back and listen to that one first, because today is part two and we're [00:01:00] building on everything that we covered.

[00:01:01] So last week we talked about why brain fog and menopause is so real, so biological, and why women over 40 are disproportionately affected by Alzheimer's and dementia. And we went deep into the mind diet. That which is that specific eating pattern that research has shown can reduce the risk of Alzheimer's by up to 53%.

[00:01:22] So if you missed it, go back. It's worth your time, I promise. But today we're talking about movement. Specifically how exercise like strength training and cardio and everyday movement can literally change your brain. And I don't mean that in this fluffy feel good way. There's real compelling research showing that what you do with your body today has a direct impact on whether your brain stays sharp and clear and functioning well even decades from now.

[00:01:52] And here's what I love about this topic is exercise is something we actually have control over. It's free. It doesn't require a prescription [00:02:00] or a membership. It doesn't require perfection. And for those of us in our forties and fifties and beyond, the window we're in right now is one of the most important times to start or to stay consistent.

[00:02:12] So here's what I wanna talk about today. I wanna dive a little bit into research. I promise I won't make it boring. I'll try to, I'll try to make it exciting, but specifically about exercise and dementia risk. Also, what is happening inside your body and your brain when you move? How strength training specifically protects your brain.

[00:02:34] What cardio does at that cellular and vascular level, and why even just walking matters more than you think, and what a realistic brain protective movement routine it can look like for women over 40. But before we jump into the meat of today's podcast, I wanna ask for just a little help. I've gotten some really great feedback and increased interest in my past few [00:03:00] podcast episodes, which is so exciting.

[00:03:02] So I'm working on building three different programs, one that focuses on heart health, another on brain health, and the final one on bone health. Because that's the kind of the three big topics that I've talked about in the last few episodes. And all three of these will have an exercise and a nutrition component.

[00:03:19] 'cause I've talked about the importance of both in each of these areas. But I wanna know which one interests you more. So I would really greatly appreciate it if you took literally 30 seconds to email me at info@strengthinnutrition.com. And I will drop that in the show notes as well with just one word about which of these three interests you.

[00:03:41] More so either put heart, brain, or bone. If none of them interests you, just put none. And let me know if there's another topic that you wanna know more about when it comes to nutrition and exercise or health and wellness. And if all of these three topics are interest, you put all. [00:04:00] This will also help me to know what my audience wants to hear more about on the podcast.

[00:04:05] Okay. Enough of that. Let's get into today's topic. So let's start with the research, because I want you to understand this is not just a fad or a wellness trend. This is really science. They've done a lot of research on this. The first one was a landmark study published in The Lancet. In 2020, and I'm gonna actually put the references in the show notes so that if there's anything you wanna read more about it identified physical inactivity as one of the top 12 modifiable risk factors for dementia, meaning it's something we can actually change.

[00:04:43] The next one was a study out of the University of British Columbia. I used to live up there and that found that regular aerobic exercise increased the size of the hippocampus. Do you remember that word, that big word that we talked about last? Last POD podcast [00:05:00] that is the memory center of the brain, and it's loaded with those estrogen receptors and it starts to shrink.

[00:05:06] During menopause, exercise was shown to increase the hippocampal volume by approximately 2%. I know it doesn't sound like a lot, but it actually can mean a lot it can effectively reverse that age related shrinkage by one to two years. Next is research that was published by the JAMA Neurology. So the Journal of the American Medical Association.

[00:05:29] Neurology showed that people who exercise regularly had significantly lower levels of those amyloid plaques in their brains. We talked about those last week. Those are those. Toxic proteins that are associated with Alzheimer's disease that they can see in your brain, and many times they're seeing it in a, an autopsy after your death.

[00:05:52] Next, there was a large meta analysis, and I promise there's only one more after this, so I'm almost finished talking about research, [00:06:00] but there was a large meta-analysis that looked over 163,000 participants. That found that regular physical activity was associated with a 35 to 40% reduction in the risk of developing dementia, and that's comparable to what we saw with the mind diet.

[00:06:18] Remember we talked about that last week? When we combine those two things with when the exercise as well as those increasing our intake of those 10 foods that we talked about last week, those numbers get even more powerful. And the last study I wanna talk about is the Women's Health Initiative study, which specifically found that women who were physically active in midlife had significantly better cognitive outcomes later in life.

[00:06:47] And that the risk reduction was especially pronounced for women who maintained activity during the perimenopausal and early postmenopausal years. So why does this window [00:07:00] matter for us? The years between 40 and 65 appear to be this critical window for building what researchers call cognitive reserve.

[00:07:10] So if you think of it like a savings account for your brain, the more you deposit now, the more you have to draw from later exercises. It's one of the most powerful deposits you can make. All right, so now let's move away for a second from research. 'cause I know that can be a little bit bland, but here's where it actually gets really interesting because it's not just that exercise is good for you.

[00:07:36] There's specific like biological mechanisms that explain exactly why movement protects the brain. Let's break these down a little bit. So there's something called BDNF. So every time you exercise, your brain releases a protein called Brain derived Neurotropic Factor, or BDNF, and I like to call it a little bit of miracle growth [00:08:00] for your brain.

[00:08:00] It helps us to grow new neurons. It strengthens existing neuro connections and it protects our brain cells from damage. Exercise is one of the most powerful ways to boost BD NF, and as we age, those levels naturally decline. So regular exercise, essentially, fights that decline. Next, something that we've talked about, oh my goodness, all the very frequently in all the podcasts because it is so important when it comes to hormone support, but we talk a lot about blood sugar and blood sugar regulation.

[00:08:36] We talked about this last week too, in the contest of the mind diet and whole grains. But here's the exercise connection. When you move your muscles. They pull glucose out of the bloodstream without even needing insulin to do it. And this improves our overall insulin sensitivity with, which is huge. Why does this matter for your brain?

[00:08:57] Because insulin resistance, meaning your cells, don't [00:09:00] respond as well to insulin is so strongly linked to Alzheimer's disease that some researchers have even started calling Alzheimer's Type three diabetes. When the brain becomes insulin resistant, it cannot efficiently use glucose for fuel, and brain function starts to break down.

[00:09:19] We know the brain. It, it loves glucose, right? That is, is its primary source of energy. Exercise is one of the most powerful tools that we have to improve insulin sensitivity, especially as our estrogen drops and our metabolic health becomes more vulnerable in menopause. Or post menopause exercise also in increases heart rate and blood flow, right?

[00:09:48] And that means that we have more oxygen and nutrients that are being delivered to our brain on a consistent basis. The brain is so incredibly metabolic active, metabolically [00:10:00] active. It consumes about 20% of our body's oxygen. So when our circulation isn't good, the brain is the first to feel it.

[00:10:09] Regular cardio in particular helps you know, to keep those blood vessels flexible and healthy. It can decrease that arterial stiffness and it improves cerebral or brain blood flow, and it literally feeds your brain better, fuel more consistently. That make sense? Next, let's talk a little bit about inflammation reduction.

[00:10:34] We talked last week about how chronic low grade inflammation can increase post menopause and can physically shrink that memory center or the hippocampus over time. Exercise is one of the most well-researched anti-inflammatory tools we have. It reduces some of those inflammatory markers in our blood.

[00:10:55] One is called CRP or the C reactive protein. [00:11:00] Or the IL six, interleukin six. And it does this in a dose dependent way, meaning that consistent, moderate exercise is consistently anti-inflammatory. We know there's so many things in life that increases inflammation, stress, poor diet, lack of movement.

[00:11:19] But exercise can help to just, keep counteracting that. So it's also one of the best regulators of cortisol over time. So acute exercise, it temporarily raises that cortisol level. And if you remember I talk about this a lot, but cortisol is that fight or flight hormone, right? And cortisol is very important in our body.

[00:11:43] If you haven't had a chance, I one of my last podcast episodes, I'm gonna find it for you. It. Was on cholesterol and it was called naturally balanced cortisol for better Sleep energy and hormone support. That was episode 33, and I will link that in the show notes. [00:12:00] If you wanna read more about cortisol.

[00:12:02] But super interesting. But cortisol is super important in our body and we need it. It's, some people talk about it like it's just this bad thing. No it's what helps higher levels help to wake us up in the morning, help us to be, awake and have energy and start our day off on the right foot, right?

[00:12:21] So we naturally see those cortisol levels are gonna be higher in the morning as the day progresses, they're gonna decrease or they're gonna slow, they're gonna become less so that we can wind down and get sleepy and go to bed at night and get a good night's sleep. But when those levels are. Are out of whack too low in the morning, we might notice that we're not hungry in the morning.

[00:12:42] We might notice that we're fatigued. We don't wake up with energy and if they're too high in the evening, we struggle to fall asleep, which can increase that fatigue, right? So exercise is one of the best regulators of our cortisol. We see that [00:13:00] acutely, or in the short term, it temporarily raises cortisol.

[00:13:03] But when we're doing exercise regularly and consistently, it actually lowers our baseline cortisol levels. So it can counteract maybe what what stress is doing by increasing our cholesterol levels. And it improves our stress response. Since we know that chronically elevated cortisol, it literally shrinks our hippocampus or our memory center, and this is a big deal for long-term brain health.

[00:13:32] So now let's chat just a minute about strength training. Because I think this is the one that surprises people the most. I often talk about strength training in terms of, body composition and metabolism and bone density, and all of these are. Real, they're important, especially for women post menopause, but the brain benefits of strength training are genuinely remarkable.

[00:13:55] So taking a step back and talking just a second about research, there was a [00:14:00] study out of University of Sydney that found that strength training even just twice a week, was associated with significant improvements in cognitive function. Specifically in our memory and our attention, and I'm sorry, but I don't know about you, but postmenopausal, that is one thing I've really noticed is I struggle with focus.

[00:14:21] I feel like I'm all over the place, but the effects were so pronounced when training intensity was higher. So this is another reason to challenge yourself. There was a research published in the Journal of the American Geriatric Society, and it found that resistance training or strength training was specifically beneficial for executive function.

[00:14:45] So that's just our ability to plan, to organize, to focus, and to make decisions, things that can really feel somewhat foggy during perimenopause and post menopause. So why you may ask like what is [00:15:00] strength training doing biologically or why does it matter? Muscle contractions. During resistance training, it actually triggers something called myokines or the release of the myokines.

[00:15:10] And what those are is they're proteins that are secreted by our muscles that actually travel to our brain and have neuroprotective effects. There's one in particular. It's called Irisy, and it's been shown to increase our BDNF. Remember, we talked about that levels and improve our brain function or our cognition.

[00:15:31] Strength training also improves that insulin sensitivity in a really unique and powerful way because muscle tissue is the body's primary site of glucose uptake. The more muscle that we have, the better. Better. Our body manages blood sugar. And as we just talked about, blood sugar management, it's directly linked to brain health.

[00:15:51] Resistance training also helps to maintain the integrity of the white matter in our brain, and those are specifically the communication [00:16:00] pathways between different areas or different regions of our brain, which naturally can decline with age. So a little practical guidance around strength training, you'd be like how often should I do it, and what do I need to do?

[00:16:13] So we're aiming. For two to three sessions a week, right? That's not bad, right? You do not need to lift incredibly heavy. What matters more is that you're challenging your muscles, you're progressing over time, and you're staying consistent. You've heard me talk about progressive overload, right?

[00:16:34] Compound movements that use muscle groups at once, like squats and dead lifts and rows and presses, they're gonna give us the most bang for our buck, both metabolically as well as neurologically. All right, so now moving on to cardio being that third main type of exercise and cardio has actually been the most studied form of exercise in [00:17:00] relation to brain health.

[00:17:01] And the evidence is really compelling. Aerobic exercise is the primary driver of that BDNF release. We see that higher intensity intervals appear to produce even greater spikes in the BDNF than steady state cardio. So a mix of both is ideal. Regular cardio promotes neurogenesis. And what that is that creation of new brain cells, specifically in that memory center in the hippocampus.

[00:17:31] And this, this is remarkable. We used to believe that the adult brain could not grow new neurons. We now know that's not true, and aerobic exercise is one of the most powerful triggers for that neurogenesis. And cardio improves our vascular health, which we know directly supports the brain.

[00:17:49] So because it reduces our blood pressure, it improves that arterial elasticity and ensures just that nice, strong cerebral blood flow, gosh, I can't talk [00:18:00] today. So that flow from our to and from our heart, and they've found that poor cardiovascular health, it's one of the biggest independent risk factors for dementia.

[00:18:11] So when we aren't getting that good circulation through the body of blood and oxygen through the body, current research and kind of general guidelines they point to about 150 minutes of moderate intensity aerobic exercise per week, or 75 minutes of vigorous intensity act activity. But here's the thing, even walking counts, even 20 to 30 minutes of brisk walking several times a week shows meaningful brain benefits.

[00:18:39] It's not about training for a marathon, it's about just getting your heart rate up consistently. So for women in menopause, I love a combination of brisk walking or hiking. Accessible low impact reduces cortisol and it connects us to nature, which is so important. Just getting that sunshine on our.

[00:18:59] [00:19:00] Next, like cycling, dancing, swimming, or any cardio that you actually enjoy, it's gonna be more therapeutic than doing something you absolutely hate. And then that HI training or interval training one to two times per week. If your body tolerates it, not everybody can do hi training. I personally with my clients, I like to do sprint interval training, which is, typically only about six to eight minutes.

[00:19:27] It's about 30 seconds of higher intensity, and then we relax for. The next 30 to 40 seconds, the evidence on those BDNF spikes from intervals is really cool. It's really awesome to see how that can benefit specifically women in post menopause. It's, and it's so easy to incorporate into your workouts even as a warmup to start off before you jump into strength training.

[00:19:55] So another thing is I wanna talk about is something that often gets overlooked in these [00:20:00] conversations, and that is just that, that everyday movement. You know what we call neat or non-exercise activity, thermogenesis it. Research is showing that just prolonged sitting, which so many of us are doing, working on the computer.

[00:20:16] Most jobs, are frequently sitting for long periods of time. Even if you're somebody who is exercising three days a week. It's independently associated with cognitive decline and a greater risk of dementia. So sitting for long and broken stretches, stretches, it's a brain health risk on its own.

[00:20:36] It matters so much when you have desk jobs and you're working from home, or you're spending a lot of time sitting in the car driving. So the goal is to break up that sedentary time throughout the day. You can do things like setting a timer, getting up and moving for five minutes every hour.

[00:20:53] You could take a 10 minute walk after your meals. This is also really positive for blood sugar [00:21:00] management after eating. And there is emergency res emerging research specifically on that post meal walking and cognitive health. You can choose the stairs, you can park farther away, you can do your phone calls or your meetings.

[00:21:16] Walking or standing, even things like gardening or playing with your grandkids or your dog or dancing in your kitchen. All these things count for that. Neat. The takeaways here that a one hour workout, three times a week does not fully undo a 10 hour day of sitting movement throughout our day is a separate but important layer of brain protection.

[00:21:42] So now I wanna take a second and make this practical. So here's what a Brain Protective Movement week looks like for a woman over 42 or three days of strength training. Challenging compound movements, maybe 30 to 45 minutes per sec per session if possible. But you know what, [00:22:00] if you're just starting out and all you can do is 15 minutes, then do 15 minutes.

[00:22:03] That's fantastic. 150 minutes of moderate cardio across the week. So this can be broken up into 20 or 30 minute sessions of brisk walking or cycling, dancing, swimming, or whatever you love to do, and then one to two days of that intentional higher intensity cardio if tolerated those intervals, could be like a fast hike or it could be, a little sprint interval training before your workout or a HIIT class.

[00:22:33] And then next is breaking up that sedentary time each day. So moving every hour, walking after meals, building more movement into your daily routine. I know my Apple Watch will tell me if I've been sitting a bit too long and to get up and move for a bit. And then at least one rest or active recovery day.

[00:22:51] You know where you can do like yoga or stretching or easy walks because recovery is part of this equation too. And you don't have to do this all at once. [00:23:00] Start where you are, add one layer at a time. 'cause this is about consistency over intensity every single time. So over the past two weeks, we've built, a really complete picture of what it takes to.

[00:23:15] Protect your brain through the years of perimenopause and menopause and beyond. Last week we covered kind of the biology of brain fog, why women are at higher risk of Alzheimer's and how that, what we're eating and specific foods can reduce that risk by up to 53%. So this week we layered on that exercise piece, and what I hope you heard today is that movement is not optional when it comes to your brain health.

[00:23:41] It's medicine. And here's what I want you to walk away with. You know your body and your brain are so deeply connected. So when we strengthen our muscles, you're also strengthening your mind. When you get your heart rate up, you're feeding your brain. When you improve your insulin [00:24:00] sensitivity through exercise, you are directly reducing one of the biggest drivers of cognitive decline.

[00:24:06] And when you keep moving throughout the day, you're protecting the very neural pathways that keep you sharp and present and fully, in your life. You don't need to overhaul everything at once. You pick one thing from today's episode and you start there, maybe it's committing to two strength training sessions this week.

[00:24:27] Maybe it's adding a 20 minute walk after dinner, three nights a week. Maybe it's just simply setting a timer to get up and move every hour. It's about the small, the consistent, intentional steps, and that's what this is about. So if you've been listening to both parts of this series, I want you to think about how the food piece and the movement piece work together.

[00:24:50] The mind diet feeds and protects your brain. Exercise grows new brain cells, improves blood flow, reduces inflammation, and builds insulin sensitivity. And [00:25:00] together they're giving us our brain, the most powerful combo of tools available to us. So if today's episode resonated with you, I'd love if you would subscribe to the podcast.

[00:25:15] It's totally free. So you never miss an episode, and I want you to think of one woman in your life who needs to hear this, like a girlfriend who's been joking about forgetting things, or a sister who is, in the thick of perimenopause or post menopause, or maybe even like your mom who's struggling with memory issues.

[00:25:31] Send her this episode. Send her both parts, because this information can genuinely change the trajectory of her health and that is worth sharing. And remember, if you could send me an email at info@strengthinnutrition.com with one of those three words, brain, bone, or heart, to let me know what most interests you when it comes to those three areas, I would greatly appreciate it.

[00:25:57] Remember, this is about progress over [00:26:00] perfection. We're in this for the long haul, and this is your season of strength. Have an amazing day.