When you go and do a single bout of resistance exercise, you prompt the release of certain myokines that positively influence the rest of the body.

Knowing at least that there is magic going on behind the scenes because you worked out today is enough sometimes for some of these days, right? Welcome to the Strength Changes Everything podcast, where we introduce you to the information, latest research, and tools that will enable you to live a strong, healthy life. On this podcast, we will also answer your questions about strength, health, and well -being. I’m Amy Hudson. I own and operate three exercise coach studios. My co -hosts are Brian Sagan, co -founder and CEO of The Exercise Coach, and Dr. James Fisher, leading researcher in evidence -based strength training.

And now for today’s episode.

Hey, everyone.

Welcome back to the Strength Changes Everything podcast. I’m here with Dr. Fisher today. Today’s episode is all about Maia Kynes. You may have heard us talk about Maia Kynes in previous episodes and wondered a little bit about what these mean and what they are. So far in the context of our conversations, I’ve understood Maia Kynes to be these magic messengers or signals or things that are released into your body as a result of strength training and they’re doing wonderful things for you. That’s kind of a very basic understanding that I have gleaned so far in the context clues of how Dr. Fisher has used this term myokines, but we’re going to describe what these are.

We’re going to describe how they interplay within our endocrine system and, um, what they’re responsible for in our body, which is all kinds of wonderful, wonderful things. I hope that the conversation today reframes your appreciation for the the act of strength training itself and understand what is going on then in your body immediately following a strength training session. and why that’s so beneficial to you on so many levels. It’s not only about getting stronger, there’s so many other wonderful things going on and we hope to break those down for you today and give you that appreciation at a deeper level. How’s it going, Dr. Fisher?

I’m doing great, Amy. Thank you.

How are you?

I’m doing great. I am excited to dive in a little bit more on this with you. So where would you like to start this conversation today?

Yeah, well, first of all, what a wonderful description that you gave of myokines. We have used this term numerous times in the podcast, and we’ve never really got into a huge amount of detail about this. We can certainly kind of break this down a little bit in context today. The reality is that we could produce an entire series of podcasts discussing myokines in detail in their mechanisms and in the adaptations that they can stimulate. But Loosely, what you said at the start was completely true. So myokines are basically signaling messengers released by contracting skeletal muscle that positively go off and influence the rest of the body.

And they’re involved in anti -inflammatory, metabolic processes, immunological processes, then know that they can positively impact human health by, uh, you know, fighting things like cancer, neurological diseases, and numerous other non -communicable diseases. So to think about them as this kind of magic towel that’s released for muscle, it’s not completely untrue. And when we talk about this, we’re talking about the last 20 years of research. The term myokines was first coined in scientific literature in 2003. So we really are talking about a very contemporary topic here.

And so when when people discovered this concept, named it myokines it’s because they were seeing these things happening in the body as a result of muscle contractions and they dug a little bit deeper to understand what exactly was happening and the mechanism for that and they finally named it something and there are multiple kinds of myokines, correct?

Yeah, absolutely. So in a minute, we’re going to have to take a step back and kind of explain the myokine system and the muscular system in context of the endocrine system. But before we get to that, yes, absolutely. So for a number of years, probably a couple of decades through the 1980s and 1990s, it had been recognized that contracting skeletal muscle releases some cells that impact other areas of the body. So prior to this, and even through this time, skeletal muscle was thought to be hugely beneficial because it was metabolically active. So people placed it in context of other human tissue, e compared it to fat, and they said, hey, fat is not very metabolically active, muscle is very metabolically active. That means it burns more calories, and therefore, You don’t want fat, you want muscle. And that’s 100 % true. There’s no greater statement than that. But the reality is that’s not where the benefits end.

So through the 80s and 90s, they’d realized that there was something released by skeletal muscle. And it’s one of the myokines that we’ll talk about briefly. And they had referred to it as a muscle contraction induced factor or an exercise factor. And it hadn’t really got its name yet. And it wasn’t until 2003 that somebody called Bengt Salten first used the phrase myokines, myo meaning muscle and kines meaning movement. And it’s basically

that the contracting skeletal muscle released these myokines or skeletal muscle cytokines, which are hormones or signaling cells which go off and impact the rest of the body. Now it’s worth at that stage clarifying one of the key authors on that first paper was somebody called Bente Pedersen, a phenomenal Danish researcher, and she really has been the leader in this area for the last two decades, uncovering new myokines and giving context to numerous other the Mayakines. And if you now go onto Google Scholar and start to put in, you know, Mayakines as a term, then you’ll see just the wealth of research that’s out there. You know, they’ve now uncovered, you know, six or seven hundred Mayakines and more are being discovered and that they’re estimating that a few hundred more will be discovered. So it’s just a phenomenally exciting and growing area of research with regards to contracting skeletal muscle in context specifically of resistance training actually.

Yeah. I don’t know if a lot of people out there conceptualize muscle as like a chemical messenger sender throughout the body. I think it’s easy to think of it as just a structural piece, a physical object within a body and that’s it. But in fact, it’s chemical in nature, right? Because it’s sending these chemical signals out to do all sorts of things.

So that’s pretty interesting. Yeah, that’s exactly right. And that’s where really we can take a step back and talk about the endocrine system. So many people may or may not have heard of the endocrine system, or as we kind of briefly touch on it now, they may be familiar with certain parts of it. So the endocrine system is a network of organs which receive and interpret chemical signals and then respond by releasing other signals or hormones to make changes in the body.

So for example one of the key things that we talk about is the hypothalamus. So the hypothalamus effectively interprets our core temperature and in response to that sends signaling messengers back around the body to say, well we’re too hot, core temperature is going up. So we need vasodilation that sends the blood to our periphery, to our skin, so we might get that red flushing effect. And then it might even prompt sweating. Or it might say we’re too cold, we need the blood that’s in our periphery to come away, and then we end up with kind of white fingers or toes. And it kind of warms our core, and it might even prompt shivering, which is our hair standing on end, and micro contractions in the muscle to try to prompt warmth.

And that’s all a response by the hypothalamus. We then have things like our pancreas, which again, people might be familiar with, and that interprets blood sugar levels, and it produces hormones like insulin or glucagon that basically send signals to store that blood sugar, or the sugar that’s in our blood, I should say, into our muscles or our liver to make sure that we have that sugar for later use, but also to make sure it’s not just traveling around within our blood. So there’s a number of organs within our endocrine system that serve multiple functions. You know, we could talk about it across a number of ways. People may have heard of things like the thyroid and they may have heard things like an underactive thyroid, which would be kind of an underactive metabolism and things like that. Or they may have heard of some of the syndromes associated like Cushing’s syndrome.

and things like that, which are associated with problems with metabolic, sorry, with endocrine function. So we have this endocrine system within our body that’s constantly doing this, regardless of what we do. So if I eat, my pancreas doesn’t need a prompt to do that. It simply interprets those messages. And so We’ve thought about muscle as this metabolically active organ, but now we can actually think of it in context as an endocrine organ.

And a direct quote, I’m going to read you a few direct quotes today, but a direct quote from a recent research paper said, it’s now well established that the muscular system is the largest endocrine organ in the body, producing a range of hormones and cytokines signaling all other tissues, organs, and systems.

So muscle, when we contract it, during exercise is working to release these hormones or these myokines to positively impact other areas of the body. Yeah, it’s like when you exercise and contract your muscles during a strength training session, you’re bathing your body in these positive chemicals that are going everywhere impacting how you feel, impacting how your body produces energy, and all these other factors that you just described a few of with the endocrine system.

So there’s a lot more beyond the, again, the physical working of the muscles themselves going on, which is pretty cool. Yeah, absolutely. And you really nailed it when you said when you do a resistance exercise session. So it’s a single bout of resistance exercise. This is not a product of, oh, I’ve been strength training for six months. Now my muscle will start to release myokines.

When you go and do a single bout of resistance exercise, you prompt the release of certain myokines that positively influence the rest of the body. And I love this because we can put this in context of Hey, if you’re in doubt as to whether you should or shouldn’t train, this is probably the tipping point that says, just go do a workout. Just go do something, even if it’s not your best workout.

it just has to be the best that you can give on any given day and keep those workouts regular, keep sustaining them because they’re constantly, every single time you engage in it, they’re doing something positive to help the rest of your body. Yeah, even if you can’t immediately see or feel something, knowing at least that there is magic going on behind the scenes because you worked out today, is enough sometimes for some of these days, right?

You just know you’ve done something amazing for your body and your body thanks you for it. Yeah. Yeah, absolutely. And of course we get, you know, focused on the adaptations that we can see. So we might engage in resistance training because we’re interested in weight loss or strength gain or building muscle or maybe the cognitive benefits or cardiometabolic benefits or so forth. And of course, they exist.

We’ve talked about those extensively in the podcast. We’ve talked about diabetes, and we’ve talked about cholesterol, and we’ve talked about blood pressure. But the fact that myokines are being released, irrespective of whether those adaptations are occurring, is a really positive thing. And in fact, we’ve talked about myokines on the podcast because, in part, myokines are some of the positive things that are happening to stimulate those adaptations. So, for example, we’ve talked about chronic and systemic inflammation in the past.

We know that there are myokines that are released, which help to reduce that chronic inflammation, reduce something called C -reactive protein levels and visceral fat.

So, you know, the release of myokines is just such a phenomenon that is really worth talking about today in regards to our overall health. So you just said there’s a myokine that is responsible for reducing inflammation and reducing visceral fat? Yeah, absolutely. So if we start to get into a few of the myokines, But there’s a myocan called interleukin -15, and this is negatively correlated with visceral fat. And that’s to say that if this is elevated, visceral fat is reduced.

And one of the things that’s thought about is that mechanistically, interleukin -15 actually reduces or shrinks fat cells. So it effectively dehydrates them and makes them shrink down, so they just can’t store as much fat in and of themselves. And then it also works to support the recruitment and activation of what’s called natural killer T cells, which are lymphocytes acting in response to pathogens or tumors and autoimmune disorders.

So, you know, we’re contracting muscle, we’re releasing these myokines that travel off and they’re working to combat infection, autoimmune conditions, tumors, so on.

So, you know, from an inflammation and immune support, you know, They’re doing a phenomenal job and our strength training, which is something we might not think about in that context, is going to be a key part of that part of our health.

So my strength training workout is sending out interleukin -15 to shrink my fat cells and to make my immune system healthier and stronger.

100 percent. What a wonderful thing. I love it.

What else you got for us? Yeah. What are some others? Yeah, absolutely. So let’s talk a bit about metabolic regulation.

So this is where we typically think about the start of of myokines, the first one really that was coined was interleukin -6.

So we’ve just had interleukin -15, this is interleukin -6. And interleukin -6 is a really interesting myokine actually. It’s often put in context as an analogy to coffee. So if you have too much coffee, then you might feel jittery and burned out and it can have negative effects. But small spikes in caffeine can help you feel energized and focused.

And so when we do strength training, when we engage in strength training, we’re prompting the spike in interleukin -6. And that’s serving to combat kind of autoimmune diseases, to prompt our metabolism, to fight chronic inflammation and insulin resistance, and so forth. So it’s playing a key role across a number of kind of different variables.

So is interleukin -6 inflammatory for just a little bit of time post -workout, but then overall its effect is anti -inflammatory? Is that how it’s compared to coffee? Okay. Yeah, absolutely. And if people go away and read it, they will absolutely see that, oh, it’s both pro and anti -inflammatory. That kind of doesn’t make sense.

Well, no, pro -inflammatory is good. We want things, inflammation inherently is important for our body. If we have an infection or if we have an injury, inflammation is good. We need that.

What we don’t need is chronic inflammation.

So spikes, small spikes are great.

prolonged spikes or, it’s not a spike anymore, but prolonged elevation is bad. Gotcha. So interleukin -6 is doing us a favor in the inflammation department. So yeah, absolutely. And then another one, which we briefly spoke about before we started the podcast today is one called irisin. And to put irisin in context, we first have to talk a little bit about fat.

So there’s actually two types of fat, and we typically think about fat as being inherently a bad thing. And that’s okay. When we talk about it as a bad thing, we’re typically referring to white fat. So white fat is bad. But we also have something called brown fat. And brown fat is good from a thermogenic point of view.

It helps to maintain body temperature and it burns calories or certainly burns more calories than white fat. Now, brown fat’s been kind of prominent in literature in the last decade or so with the idea of getting in cold tubs and cold plunges, where some evidence suggests that there is a browning of white fat with this cold exposure. Well, irisin does exactly this. It has a browning effect on white fat. So, we may have this white fat, And that’s bad.

But when we do strength training, as well as reducing fat and shrinking fat cells, as we’ve just talked about, it also serves to release irisin.

And irisin serves to have a browning effect on white fat cells. So again, it serves to increase our metabolism in that way.

So it’s making our white fat cells behave more like brown fat cells, which are more metabolically active, kind of like muscle.

and increases energy expenditure and mitochondrial density and loads of positive things that are really too complicated for me to get into on this podcast. They’re too complicated for me to discuss rather than to discuss in this podcast. That’s saying a lot.

Yeah, the complexity of this area is phenomenal. But yeah, loosely, that’s exactly what it does. Whenever we talk about myokines, it almost makes me laugh because I think, It’s described as like this magic power and it’s not wrong to think of it in that way.

No, no. I picture like a glowing character in a video game that’s like alive with all these sparkling chemicals flowing all the way through it. Yeah.

You know, and experiencing all these fabulous things every single time you straight train.

I’m going to age myself now, but in my head, I think about when Popeye ate the spinach and all his muscles grew and he had that kind of big effect.

I almost think about you do a strength training workout and all your muscles just, like you said, glow or have this effect where they suddenly send off all these signaling proteins that make you so much healthier and so much better and impact your metabolism and your inflammatory system and your immune system and so forth.

So, yeah. Absolutely.

But there’s more. There’s more. But wait, there’s more. Exactly, exactly. So we haven’t talked about cognitive function and this is one of my favorite areas to talk about with regards to resistance training because it’s probably one of the most overlooked. We know about a lot of the physiological benefits of strength training and we’ve spoken briefly about some of the psychological and mental health and cognitive benefits of strength training.

But one of the key myokines that’s talked about is called BDNF, which stands for brain -derived neurotrophic factor. And this is linked to what’s called neuroplasticity. And that’s basically your brain’s way of kind of reorganizing itself and making new connections so that First of all, we can learn new skills and we can learn new things, but also it’s our ability to kind of recall information that we’ve already had. So if we can think of our brain through the day, as we take in all this information and it’s like this storeroom. where we just throw information and we just throw it all into this storeroom. But then actually neuroplasticity, and to some extent, this is where sleep is really important, helps our brain reorganize all that information.

So it kind of goes in with these filing cabinets and it says, okay, I’m going to put that, I’m going to file that there. And I’m going to file that there, but it makes all these connections in between. So that when we want to recall information, we can find it. But when we also want to recall skills, we can, we can find those and we can develop new skills and so forth.

But it’s also, as if there needs to be more, it’s also linked to some mental health conditions, things like bipolar disorder, anxiety, depression, and even cognitive impairment and alcohol dependence. So where our brain can start to falter, almost as a natural process of kind of modern society, based on some of the things that I just mentioned, actually, BDNF, brain -derived neurotrophic factor, can help to combat those things. So where we’re suffering from depression as part of a cognitive condition or alcohol dependence or things like that, BDNF is linked to kind of combat some of those things, and exercise as a whole, and specifically strength training and the release of BDNF is shown to sort of combat those cognitive and psychological conditions. Oh my gosh, that’s so great. People care a lot about brain health and what their brain is doing and how sharp they feel and how mentally they feel, because again, we’ve talked about this before, that your mind basically dictates your entire human experience overall.

And you can tell when you’re not firing on all cylinders. And so people want to feel like they are firing on all cylinders.

And you’re saying this BDNF will help us help our brain stay as sharp as it can and avoid some of the pitfalls that it’s going to steer us in the wrong direction, which is fascinating and amazing as well.

Absolutely. Absolutely. And there’s more from a cognitive of view. We can also talk about another key myocline called IGF -1 or insulin -like growth factor 1. And this has been linked to neuroprotection and myelination and synaptic growth.

So our neural system has what’s called a myelin sheath around it. And that myelin sheath effectively protects the transference of the electrical impulse down our nervous system to perform things like muscle contraction or perform growth and fine motor skills, so large or very refined motor skills.

So IGF -1 is linked to myelination, so our ability to protect that nervous system with this myelin sheath.

And that, of course, is also linked to psychological elements like cognitive function in older adults and things like that. We have multiple myokines serving in all of these areas.

And, you know, I almost feel like I can’t do this justice by going into the depth that’s necessary, but hopefully it’s starting to give people an idea of, of some of the great benefits. Yeah. I mean, we’ve just mentioned multiple, so many different things, you know, so many different things that directly impact how we feel. So even understanding it at that basic of a level helps.

And then the last area we were going to talk about briefly today was muscle and bone growth.

So, you know, our musculoskeletal system. So one of the key things we should put in context here is we have something called myostatin. And we’ve briefly talked about this on the show in context of, I think we may have shown an image of a myostatin deficient bull, a Belgian blue cattle. Yeah, absolutely. It’s often referred to as a double muscle cow. So there’s this thing called myostatin, and myostatin inhibits muscle growth.

It kind of makes sure we don’t grow too much muscle. And of course, that’s really important, but anything that’s inhibiting muscle growth is also going of working against us because we want more muscle to some extent, or we want to grow while we can to give us that edge over our aging process when we will naturally start to lose muscle.

So two key myokines that are released are decorin and folistatin, and they both work to inhibit myostatin. So they effectively block myostatin from doing its job of inhibiting muscle growth. So we do a resistance training workout, and not only have we prompted growth hormone, we’ve prompted things that will help us to grow muscle, but we’ve also released myokines that inhibit myostatin, which would have prevented muscle growth. So we’ve got other myokines like that that are working effectively to support muscle growth. That’s pretty good.

I mean, I would be it would be a shame if if our body didn’t do that, because it’s like, you know, I’m working out and I’m trying to get stronger by strength training. And then if my body were to basically cancel that out by dumping too much of that myostat in my way and preventing me from gaining muscle, that would be a little discouraging. So I’m thankful to know that that’s not happening, that in fact, we’re sending signals to to stop that anti muscle building effect. because of the strength training session. Yeah. And then we’re going to take a step back to one of the myokines we’ve previously talked about, that’s IGF -1 or instant light growth factor 1.

And this is a myokine that we’ve talked about in context of cognitive function, but it’s actually also linked to muscle growth and satellite cell proliferation and protein synthesis. So in that way, it helps to increase muscle protein synthesis as a product of strength training and satellite cell proliferation, which is important in building new muscles. but is also linked to osteoblasts. are the building blocks of new bone. So one of the ways that I sort of think about IGF -1 is it’s very much an anabolic myokine. It’s certainly got anabolic properties.

And the way that we can think of that is that our body, when we’re young, is in an anabolic state. While we’re in a growth state in our early years, teens or late teens, maybe even our early twenties, we’re building, we’re building bone density. We’re building muscle. We’re building our stature, our brain and so on and so forth. And in our later years, we’re back.

We’re kind of declined into a catabolic state. We’re losing all of those things. Well, we elevate our IGF one as a product of resistance training, and that effectively serves to reverse our, our. aging by returning us to an anabolic state, both in muscle building, in bone building, and of course, like we said, in cognitive function. So it’s hugely important in that context. I love to tell people that strength training is anti -aging.

I just love it. Don’t we all want to like look, feel and function younger than we are age? At least after we get to a certain age, I think we all do. And it’s like the best compliment you can ever receive.

But this explains exactly why strength training is anti -aging on multiple levels. It’s not just about muscle. It’s about cognitive and it’s about skin elasticity and it’s about bone strength. And all these other factors are at play here. And it is so, so exciting, you know. Well, you can see I’ve got my strength changes everything t -shirt on today.

And I was thinking about this before the podcast, because we can see aging without strength everywhere. We can look around us and we can identify aging without strength because it’s frailty. It’s a lack of dependence. It’s an independence on other people. It’s maybe a lack of socialization or a lack of engagement in tasks.

It’s a loss of functionality and so forth. But it’s almost harder to see aging with strength because it’s what we expect. It’s that independence It’s that functionality, it’s that cognitive performance that we’ve had all of our life. We’re just not having that same decline. So I love to think about how strength training itself has all of these positive adaptations that we’ve talked about on the podcast, but also this Myokine release that’s simply are muscle contracting to send these signaling messengers around the body to positively influence all of these other things that, like you say, serve to keep us young and either reverse the aging process or retain our biological youth. Yep.

And we’ve said this before, and I think everybody out there understands, you know, healthspan and lifespan. Lifespan, how many years I’m going to live. Healthspan, how many of the years I live are healthy years.

This is what we’re all about. We are all about promoting longer health span for people.

I don’t know anybody out there who would like to live 110 years, but for the last 40 of those, be sick, immobile, in pain, frail, unable to do anything, right?

We are looking to extend our health span as long as we can to make it as close to our total lifespan as possible so we can enjoy our life. And this is one way on many, many levels that this is going on. Dr. Fisher, do you have like a favorite myokine that you described today or one that you feel like is the maybe least known or most exciting? I don’t have a favorite myokine. Maybe I should.

You’d be a favorite. I’m still so old.

by the whole concept.

I love the idea that there are myokines fighting myostatin.

I love that there are myokines that are improving neuroplasticity as well as improving muscle growth and bone growth. I guess if I’m pushed, I’d have to pick IGF -1. Okay. Is that the one with the brown fat and the white fat? And IGF -1 was linked to our muscle growth and our bone growth and also our neuroprotection. Ah, yeah, yeah. I don’t have a favorite because I’m not the person who described the information today. They’re all my favorite, but I think that they’re all exciting as well in different ways.

I hope today’s conversation, if you’re listening to this, framed your perception of what you’re going to do at your next workout as this magic experience for your body.

It’s not just about strength building, it’s about everything else in your body and I hope it encourages you to know and to have a picture of what’s happening as a result of it. It is truly magic. Dr. Fisher, any closing remarks? I have nothing to add. I really hope that people have gained some insight into just how wonderful muscle and strength training can be. Yes, absolutely.

Well, thank you for being with us today. We will see you next week on the podcast. I hope you remember strength changes everything. Thanks for listening. If you enjoyed today’s episode, please share it with a friend. You can submit a question or connect with the show at strengthchangeseverything .

com. Join us next week for another episode and be sure to follow the show on Apple Podcasts, YouTube, or wherever you get your podcasts so that you never miss another episode. Here’s to you and your best health.