And welcome back, team, to the Building Lifelong Out These podcast. Thanks so much for stopping by. I really appreciate it. My name is Jordan Rennicki. If we haven't had a chance to meet yet, I'm a dual board certified physician in family and sports medicine. And the goal of this podcast is to keep you active and healthy for life through actionable Edmonton form education. Today, we're talking about knee arthritis and running. So, a lot of times I look at comments on YouTube or whatever and they say, enjoy arthritis later to people who are running. And is that necessarily the case? As a sports doc, I never want to limit what someone can do, right? I'm not going to say, hey, you shouldn't run. A lot of times, your body will throttle what you can and can't do. But today, in this YouTube video, I talk specifically about. Running in away, and how it's not necessarily as simple as if you run, you're gonna get away. I hope you enjoy the video. You've heard it a thousand times: running destroys your knees. It's just common sense, right? You pound the pavement, you create load and friction, and eventually you wear down the cartilage on your knee until it's bone on bone. People even talk about the wear and tear of running. It's all over. That's what people talk about. And this makes perfect sense if your knees are car tires or ball bearings in a machine. But here's the problem: you aren't a machine, you're a biological organism, and biological tissue does not behave like rubber. The fear of wearing out our joints is actually one of the biggest barriers to keeping people active. I see it all the time in clinic. People stop doing what they love and what keeps them healthy because they are terrified. They're writing a check. That their knees can't cash later in life, right? They think that every mile is just ticking clock until they have to get a knee replacement. But what if I told you that when we actually look at the highest quality data, specifically a massive meta-analysis of over 114,000 participants? we actually find the opposite and that running might be protective. We found that recreational runners actually have a prevalence of nearthritis of just 3. 5%. Compare that to sedentary, non-running people, and their rate was 10. 2%. That means that sitting is still statistically three times more dangerous for you than going out for a run. And obviously, in previous videos, I've talked about how arthritis is not necessarily. Wear and tear, it's more metabolic, and so people who are more sedentary that may play a big factor, but it goes to show right away that running doesn't necessarily mean your knees are going to give away. But, and there's always a but, right? There may be a limit. There is a specific weekly mileage number where the risk actually does flip and starts to climb again. And today we're going to break down what exactly that number is. We're going to look at why impact might actually be beneficial and maybe saving your cartilage. And we'll give you the practical big rocks to keep running for life. And so, first and foremost, why is this wear and tear idea so sticky? Well, because intuitively it makes sense, right? If you think about your car tires, they have a finite lifespan. Friction plus load equals degradation. And for a long time, we viewed the human body through the exact same mechanical lens. But here's the thing: you are not a car, right? Inert materials like rubber or metal, those degrade to stress, but living tissue adapts to stress. That's a big thing. And we know this with muscle, right? We know this with bone. So, the question is: why would cartilage be the only tissue in the human body that doesn't play by these rules? And well, the answer is it isn't, but I don't want you to take my word for it. Let's look at the numbers. Let's dive into the evidence. And we're not looking at a really small study of like 10 people jogging on a treadmill, right? We're going to look at a big one today: a big systematic review and analysis published in the Journal of Orthopedic and Sport Physical Therapy. Pretty solid journal, and the study pulled data from over 114,000 participants. They split people into three groups: sedentary non-runners, people who don't run. Runners, amateurs like most of us here, and then also we had competitive or elite runners, people who are professionals or people competing at an international level. And here's what they found. So, first, just to tee this up, the sedentary group, the people doing nothing, had an arthritis prevalence of 10. 2%. Now, If the wear and tear theory was true, the recreational runner should be higher, right? Well, that's not necessarily the case. The recreational runners had an arthritis prevalence of just 3. 5%. So let that sink in for a second. The runners had a third of the rate of arthritis compared to the couch potatoes. So this suggests that recreational running isn't just safe, but it may actually be protective. But, and like I said, there's always a but, right? There's definitely some nuance here. When we looked at the third group, the elite runners, their numbers jumped up to actually 13. 3%. So we kind of have this U-shaped curve. Doing nothing is bad. Doing a moderate amount is protective. Doing an extreme amount also seems to be bad. So, the million-dollar question is: at what point do we cross from protective to destructive? In this data, the cutoff for that increased risk was pretty darn high. We're talking about a volume exceeding 57 miles per week, or that's 92 kilometers per week for people who don't use freedom units. Now, I know I'm a nerd, right? And so context matters, but 57 miles a week is a lot. That's like training for a marathon, right? People who do 50 plus miles a week, that is a serious, serious runner, right? So for the vast majority of people listening, The everyday athlete who are running 15, 20, maybe even 30 miles a week, you're squarely in that protective zone and you're miles away from getting in that danger zone. So, we're feeling pretty confident that for the average runner, volume isn't the problem, right? But I do want to take a step back. So, there's this analogy I've seen on the internet about a sponge, meaning, hey, The cartilage in your knee is like a sponge, and they're saying, What actually causes the breakdown of that? Like, what are the big components that lead to that? I want to go through those real quick. First things first is it's very complex, right? It's an interplay between mechanics, genetics, metabolic health, and something called mechanotransduction, right? So, cartilage cells sense impact and this. Can be advantageous, right? It can signal the tissue to get stronger, or if it's too much, then we may lead to that issue. But it can sense what's going on, and that's called mechano transduction. Then we have genetics, right? We know that there are specific genes like a GDF5 that regulate how well your joints maintain themselves. Sometimes you just get a bad deck. That's what happens. And third, and this is huge, is metabolic health. I've talked all about this in lots of different podcasts, but that plays a huge role. So, remember that sponge analogy? I want to expand on that a little bit, right? So, we think about Hey, the cartilage is a sponge. If it's really, really dry, that's not great, right? We don't want to have a brittle, dry sponge. We want to have a nice, robust, squishy sponge. But if you go too far in the other direction, Where it's just waterlogged down, it's you know, been in your sink for like years, it's just disgusting and degrading away. Like, we don't want either of those, we want a nice, healthy sponge. Obviously, this is very, very simplified, but I'm just giving you an example to kind of look at. And if you think about it, The water and the amount of water that we have is very, very beneficial. And so, what do you mean, Jordan? What do you mean, water? Well, I'm talking about let's pretend there. If in this area, this water is inflammatory, that's bad. If you have systemic inflammation, High blood sugar or metabolic dysfunction, the fluid bathing your knee may essentially be toxic to that. So, squishing that dirty water into the cartilage doesn't help, it may potentially hurt. So, yes. Running does provide the mechanical signal to build your joint. Your genetics definitely determine blueprint, but your metabolic health determines the overall environment. And so It's not just, hey, run more to fix your needs. That's going to be better. No, that's not the case. It's, hey, let's run optimally with an otherwise healthy body, eating well, doing all those right things to create the best environment for a needs to flourish. But before we move on, I want to address a common piece of advice. That can sometimes backfire, right? I've seen well-intentioned people say, Hey, you know, if your knees hurt, just slow down, it's going to save your knees. But biomechanically, it's not that simple, right? So when you slow down significantly, you'll often end up. Taking many more steps to cover the same distance, right? So you're taking a lot more steps. And research suggests that running really slowly can actually increase the cumulative load on the knee because you're spending way more time in touch with the ground. With every step. And so that's kind of the where we get the most force is when you're actually touching the ground. And however, though, the key is nuance, right? And you have to understand how you run. So if you overstride, Slamming your heel down, you may be putting a massive brake force through your knee as well. And so, biomechanically, there's a lot of things going on. I'm not going to say it's that simple, it's never like, hey, It's just the way you run, or the cadence you have, all those things are important, but it's just not as simple. Usually, hey, just slow down, it'll be better. And so, I did just mention the cadence, right? So, often a quick fix for people. Is changing your cadence to taking shorter, quicker steps regardless of your speed, right? So you can still go the same speed, but you're taking quicker steps. By increasing your step rate, you land closer to your center of mass. This may shift the load away from the stress you're feeling in your knee. It might distribute it a little easier. You may feel better. So, that's usually one of the first things I talk to people with if they're having knee pain running: hey, where are you striding? What does it look like? So, if running volume isn't the end-all-be-all when it comes to developing arthritis, what is? And the evidence kind of points towards three big culprits. First and foremost is previous trauma. If you tore your ACL or rector meniscus, Unfortunately, that can lead to arthritis. We call this post-traumatic arthritis, and a lot of times it just is what it is. You know, we think about we're disrupting kind of that. Perfect balance in the knee when we either degrade the cartilage, we have a big fracture in there, or we erect the miscuscus, something like that disrupts things and can lead to that post-traumatic arthritis. It's pretty unfortunate, but it kind of is what it is. Second is body composition and metabolic health, right? So adipose tissue releases inflammatory chemicals called cytokines. And then these chemicals, this kind of degrades the joint faster than just straight up mechanical pounding does. And then finally, genetics always play a role, right? Some people have knees that just anything you throw at them is going to be fine. Others have more delicate knees. Well, you know, kind of think about. Maybe a Toyota lasts forever versus a Ferrari, high-performing, but needs a lot of maintenance. And so it's never that simple, but all those things definitely play a role. And so, knowing all this, How do we actually run for life, right? So, I'm going to give the takeaway here: the 20,000-foot view of like what we actually need to do to run for life. All right, so action plan number one. You're saying, hey, all right, I want to run for life. What's the first thing I should do? Well, the first thing is just kind of go easy into it, right? So we don't go too much too fast. I call it the 10% rule. But essentially, I want you to respect doing too much too soon. So, the number one cause of injury that I see is spiking your running. When I mean spiking, I mean people are sitting on the couch saying, And I don't do anything. And then all of a sudden, they're hate. I want to run a marathon. And then all of a sudden they're running five miles four days in a row. And then their knee hurts and they stop running altogether. So I want to avoid that. That's not what I'm going for. When it comes to your cartilage, if we're trying to build up your cartilage, it takes time. It adapts slowly, slower than other things like your muscles. So if you double your mileage in a month, you're just asking your cartilage to kind of catch up. And once again, I don't mean that spiking your workload is necessarily dangerous for your cartilage. I'm not saying that by any means. You know, if you have otherwise healthy cartilage, like it can probably handle it. But if we want to build up that robust cartilage and protect our knees, then taking a little slower might be better. And I generally think about increasing your volume in terms of how much you run about 10% per week max. That is essentially made up from the literature, but it seems relatively good advice to give, meaning, hey, Just little by little. So, if we're going 10 miles a week, right, in the next week, it's 11 miles. So, if it's not going from 10 to 15 to 20, you know, can some people handle that? Absolutely, but that's just a general rule. So, you can kind of follow that. So, hopefully, we're going a little bit slower. Action step number two is that strength is a non-negotiable. So, if you know me, you know that I'm going to talk about resistance training. I love resistance training. And I think even all my Endurance people who love running can benefit from having resistance training, right? You can't just run, you need to build strength. And why you're saying, Jordan, why do I do that? Well, There's many, many reasons. We'll go not into all those in this lecture, but your quads act as the primary braking system for your knees. So, strong quads may help distribute your force. And help you just keep running longer, not have injuries, right? So, if you want to run until you're 80, you need to be squatting, lunging, loading those legs at least twice a week, And I think it's not optional. It's like insurance. Like, if you want to have the best bet of continuing to be active and run, having strong lengths is going to be very beneficial for you. And now, step number three, I call the cadence check, right? So, if you are having knee pain, try out this one technical tweak before you quit and give up to it, right? So, increase your cadence by just five to ten percent. So, five to ten percent. You don't need to run faster, just step a little bit quicker. Research shows that this single change can reduce the load on the patellifemoral joint, the joint behind the kneecap, by up to 14 percent. And it's free, immediate, and works for a lot of people. And finally, I want to give you permission to not be perfect, right? So you're going to try running if you want to run, you're going to have good days and bad days and flares, and that's okay. Right, pain kind of goes up and down, and that's totally normal. But I kind of use this 24-hour rule to help guide that. So if you go for a run and your knee hurts a little bit, that's okay. Like maybe a three out of 10, I'm okay with that. That's not a big deal, especially if you say, Hey, I have some ongoing condition. I'm okay with that. But If that pain persists for more than 24 hours after the run, or if you wake up the next morning and you've got like swelling, like swelling is never normal unless you've had it previously and you're like, yep, this is just more normal knee. That is meaning we're doing too much. So, if you're having an exacerbation in your pain, your pain's flared up after a run, you may have done a little too much. You may need to pull back, kind of let it settle down, and try at a lower volume or at a slower pace or something like that. But overall, pain is information, not a stop sign. So, I don't encourage people to continue to run through, like, oh, this is terrible pain. No, but if you have a little bit of pain, that can sometimes guide you saying, okay, maybe I'm not ready for that yet. I need to pull back the mileage I'm doing or go a little slower, something like that. But listen to it, adjust what you need to, but don't let it paralyze you with fear. That's what I do not want. So, if you've learned one thing from this talk today, hopefully, it's that your knees are robust and it can handle a lot. And that running doesn't necessarily mean you're going to get arthritis. All right, that's going to do it for the podcast today. Thank you so much for stopping by. I really appreciate it. If you did enjoy this, it would mean the world to me if you either share this with a friend, liked it on YouTube, or left a five-star rating on your podcast platform of choice. That'd be really helpful. But that is going to be it for today. Hope you have a great rest of your day. Now, get off your phone, get outside, and we'll see you next time. This podcast is for entertainment, education, and informational purposes only. The topics discussed should not solely be used to diagnose, treat, or prevent any condition. The information presented here was created with an evidence-based approach, but please keep in mind that science is always changing, and at the time of listening to this, there may be some new data that makes this information incomplete or inaccurate. Always seek the advice of your personal physician or qualified healthcare provider for questions regarding any medical condition.
