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Expand your running knowledge, identify running misconceptions and become a faster, healthier, SMARTER runner. Let Brodie Sharpe become your new running guide as he teaches you powerful injury insights from his many years as a physiotherapist while also interviewing the best running gurus in the world. This is ideal for injured runners & runners looking for injury prevention and elevated performance. So, take full advantage by starting at season 1 where Brodie teaches you THE TOP PRINCIPLES TO OVERCOME ANY RUNNING INJURY and letβs begin your run smarter journey.
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On today's episode, searching for the perfect running form with Gustavo Leperase. Welcome to the only podcast delivering and deciphering the latest running research to help you run smarter. My name is Brody. I'm an online physiotherapist treating runners all over the world, but I'm also an advert runner who just like you have been through vicious injury cycles and when searching for answers, struggled to decipher between common run... myths and real evidence-based guidance. But this podcast is changing that. So join me as a run smarter scholar and raise your running IQ so we can break through the injury cycles and achieve running feats you never thought possible. Gustavo is a sports scientist. is the chief technology officer and coordinator of biomechanics research over in Brazil. He has just released a paper titled, the search for the holy grail of running biomechanics. Is there an ideal movement profile for minimizing mechanical overload? He has been grateful enough to provide the link to this paper alongside a YouTube video, which better explains these movement profiles. So you can go and check those out in the show notes. On the podcast today, we talk about the design of the paper. the exact findings, what surprised Gustavo and how recreational runners can better understand running technique if it needs to change what happens with mechanical load when we do change and overall general principles to help you minimize your risk of injury. You're going to love this one. Let's take it away. Gustavo. Thank you for joining me on the podcast. Thank you, Brody. Nice to be here. Thank you for the invitation. You're welcome. Your paper, the title, the search for the Holy grail of running biomechanics. Is there an ideal movement? profile for minimizing mechanical overload. How has this study come about? did this idea of the paper first start? you know, the science, scientists have long studied how biomechanic factors influence injury risk. However, figuring out how exactly which one matters and how they interact has been very tricky. Sometimes research findings even contradict themselves. So you have a lot of studies showing that one factor increases the risk factor, one biomechanical variable increases the risk factor, and the next year you have a second study showing it decreases the risk factor. So I'm a biomechanist for more than 15 years. I have more than 8,000 3D biomechanical analyses. So when you go to the practice and you have the numbers in front of you, you'll see that it's maybe... What we see in the research nowadays is too simple for what really happens in our body. So for the past decades, we have been doing single variables analysis, just like we look at the cadence, we look at the impact, we look at the foot strike. But the problem with this approach is that it does not take into account the complex interplay between all these variables. So that's how the idea raised. So if you apply some techniques that we can analyze the interplay among very different variables that are related during the running, how can we, how they interplay and they can show us the overload during running. Right. So like say cadence, if you manipulate your cadence, it might manipulate how Often your foot makes contact with the ground might manipulate how hard you impact the ground might manipulate how your foot strikes the ground. And so all of these things have a particular interplay. Exactly this, because you know, we treat our body just like a linear relationship. We, uh, there's some papers trying to propose that when you have a lower cadence and you have, uh, it's a lower cadence, it's a longer, uh, step length. So when you have a lower cadence, you spend more time on the ground. And, you know, when we started doing our biomechanical analysis, we didn't see this happening in all the subjects, in all the runners. So some runners just kind of have a lower cadence, but we don't know how. They have a shorter stance time. So what we try to do exactly, how can we join on these variables and see what happens with the forces? coming into the body. Okay. All right. So how was this study designed? How many runners did you recruit and what did you put them through? Nice. We recruited 79 health runners. They were injury free for one year. They have moderate to high volume of training. They had to train at least 30 kilometers per week. So all of them trained, were used to do marathons. they were recreational, They used to run properly. And we captured the kinematic data using the sensors, just like you have a lot of cameras in the lab, just like you see in these movies. And we will reconstruct the body of the subject in the computer. And we keep them running for some time. And then we extract some variables for this. OK. And based on how they were running, you were sort of trying to calculate the forces that are applied to the body at the same time? Exactly. Okay. How do you calculate the force? if you have all these reflectors on their body and capturing their movements, how does that eventually calculate force? Great question. We have many ways to calculate forces when we do biomechanical analysis. The most usual way is to use force plates. So we have some plates in the ground and then people just step over it. and then you can calculate it. But when you use trademills, it's more difficult to do this. So we have some algorithms, some equations that we can calculate the ground reaction forces based on the body kinematics, because force is nothing more than your mass and your acceleration, the second law of Newton. So we have the body mass, we have all the anthropometric parameters, and we have also the body movement, and we have some scientific reports showing how can we calculate indirectly the ground reaction forces. Yeah. So if you can accurately capture how they move, when they move, how fast they move and all that sort of stuff, you can then derive through various calculations, how much impact, how hard they're hitting the ground, how much loads going through their ankle, how much loads going through their knee and their hip and those sorts of things. Exactly this. Gotcha. Uh, and so I guess like in the paper, you mentioned the several variables that you were focusing on. Um, you mentioned cadence and like stiffness, vertical stiffness. You also mentioned duty factor as a variable, which has been something that I've come across in a couple of other papers. I haven't seen it that often. Um, so can you explain to people exactly what duty factor is and why? you decide to include as one of the variables that you're tracking? Yeah, sure. Duty factor is the ratio of the time your foot spends on the ground compared to the whole strides. So it's the ratio between the time you spend during the stance time and the flight time. So it's usually in the literature to describe if you are more terrestrial, just like you spend more time on the ground or more aerial. uh, moving, uh, running pattern. So it's, it's just a matter, a complimentary matter, uh, variable of the stance time itself. Right. I've seen that in some runners. I, I watched them like in slow mo on a treadmill viewing them from the side and you can almost see like they almost have very little flight time. Like flight time would be when both feet are in the air at the same time. And you can see like just as their back foot. comes off the ground, their other foot's just about to impact the ground. It's like you don't really see a lot of flight time. in that instance, the duty factor would be high or the duty factor would be low? The duty factor would be higher. These runners call the terrestrial runner because they spent a lot of time on the ground. So they usually don't use the flight time to spend. the movement forward, they spend more time on the ground. usually, have described in the literature, they have a higher cadence. Okay, so I'm glad. Thanks for explaining that, explain that very well. Any other meaningful data points or metrics that you wanted to particularly follow in this study? Yeah, I think one of the newest measures we included in this study, what we call the smoothness of the movements. Smoothness from a practical point of view is pretty easy to understand. It's kind of how fluid you move. Do you know sometimes you look at the runner, you can see he's doing a lot of effort to move forward. Just like, oh my God, he's doing a lot of force to move forward. He's gonna be tired really fast. And on the other hand, you have some runners that you see, it looks like he's flying, just like dancing ballet. And you know, it's pretty fluid movement. So it's movement, it's movement is a measure. It's used in the motor control area that is related to the ability of something. Just like you have some professional athletes, professional cyclists, they have a really smoother movement than non-professional athletes. When you have patients with Parkinson's disease, they have a movement less smooth than a subject without ParkSoul. So in a lot of areas, it has been used just like your ability to do a movement, how well you can do it in a fluid way. And we included this in the running. It was pretty interesting because it was pretty aligned with the amount of overload you have on your body. How fluid, the more fluid you are, the less overload you have. Right. So you call this vertical smoothness. This is movements of the movement. It's a 3D measure. It's made by your foot. Just try to figure it out. You are running. So you remove your foot from the ground, then you have to oscillate forward, and then you hit the ground. When you hit the ground, you have a change of velocity of your foot. And then if you keep the less variable You do it, the more fluid you do, the less energy you spent. Yeah. So that's what it matters. I was trying like, you can kind of pick them. You can like look at a runner and say, they look really efficient. They look like they're not expending a lot of energy, just mechanically sound, but you can, you can see it and not really work out why or work out what's actually different. You can just spot the differences, but you know, the mechanics behind it is, um, something that I couldn't really understand. So I'm glad that you've tried to analyze it and bring it into a data perspective. So that's really interesting. Okay, so any other variables that is worth mentioning? Well, the second new point of the paper of this manuscript is we use machine learning to analyze the complexity of this data. So machine learning is really popular nowadays because you have chat TPD and all these generative AIs. And you have a lot of things that people now, when you write an email, you have some AI fulfilling the sentence for you before you write it. And I have been working with this since my masters in 2010. And the nicest thing with the machine learning is because we don't pre-assume how many ways of running we have. We don't assume there is one way of running that's better than the other way. So they can calculate for you how the variables interact. And the nicest thing is they help us to identify relationships that our eyes can easily see. It's exactly what you said. Just like you look at it and say, wow, it seems soft. It seems beautiful. see these people, this guy running, but I don't know why. You don't know how, which variables are, you know, which variable matters. And with this machine learning, we could discover which variable is important for every single movement profile. So you've got these 79 runners, you've got all this data collection equipment, and then you put it all into the machine learning database, and then it sort of comes up with... some answers for you to try to answer some questions. So what did the results show in this study? First of all, there is no one holy grail. So I know that we human beings, we usually try to simplify everything and have some easy questions, easy responses for all these stuffs. It's like we have a lot of papers showing What happens if I increase 10 % my cadence? What I do if I change my foot strike? What happens if I change my foot strike? Well, the nicest thing we discovered that these variables can't act alone. They work together just like ingredients in a recipe. Changing one without adjusting the others can throw off the whole dish. So that's why just looking at just cadence or just stiffness is often misleading. So I think that the most important thing is there is no, instead of looking just for one risky variable, we have to look at an overall biomechanical pattern. like, it's like an injury risk has a biomechanical fingertip. You have your biomechanical fingertip that's not. composed only by your cadence or your stiffness. It's an interplay. And we found five different ways of running. We classify these ways of running based on the amount of load, not the amount of load, and the cumulative profile of this role. So we have one profile that's really nice to see. It's probably these guys that you see running really soft. It's called the low load. It has a low cumulative, low load, low peak load, call, just like has a low force impact and also has a low cumulative loading. And why cumulative loading is important? Because when you run a marathon, sometimes you don't have a really high impact force every single step. But when you have 40,000 steps, there is a huge amount of loading on your knee, on your ankle. So that's why a lot of people usually say, many of your listeners here are to identify themselves with this because there some people say, no, that's okay. If I run 10K, if I run just 10 kilometers, that's okay. When I run 15 kilometers, it starts hurting. when I run and there's the other kind of people say, I can run 40 kilometers if I run a pace of six minutes per kilometer. But if I put 530, I feel pain. So that's intensity, just like the amount of strike you do per step. And the other is the cumulative loading. So that's not so much force per step, but at the end of the day, when you do all these steps, it matters. So you have people that, depending on the biomechanical profile, they have more intensity matter and other has more volume importance. It's always been the argument against like increasing your cadence, which not sure what your take on this is, but like, if, if I was to say, if you increase your cadence by 10%, you reduce your like impact forces by, you know, 15 % and I can say, yeah, that's all well and good. Like I'm reducing my one impact per step, but if I'm increasing my cadence, I'm taking more steps per minute, which is more opportunities for me to accumulate load within that minute. And so I guess that's why you want to not only look at your impact force per step, but you also want to look at your accumulative load per kilometer or per minute or per mile. And so that's why those, those two things, those two variables can be important. Yeah, exactly. is. Look, look how cool is that? Yeah. The first profile, they have a low cadence. That's what usually people say, Hey, be aware because a lot of people with knee pain have low cadence and you have a lot of evidence in the literature showing that if you increase some of your 10 % of your cadence, you reduce 20 % of your impact. And that's true for most of the people. But this first profile, despite the low cadence, they have a high duty factor. They have longer ground contact. So they have more time to absorb the loading. So at the end of the day, despite the low cadence, they have lower, they are the group with the lower peak forces. So that was really interesting because we are used to say that low cadence are related to a high impact. And we found a lot of people, a lot of runners with a low cadence, and they didn't present just like a high impact. So my point is sometimes we... We try to simplify just like with basic rules. Sometimes in running, we say, have to have your cadence between 170, 180 steps per minute because it's the ideal. Some papers showed where you have the better running economy. That's okay. But it's interesting. We found that some runners run with a lower cadence, but still with a lower impact forces. And that's cool because maybe it... Maybe cadence for this group should not be the variable you select to change it. You mentioned five profiles that the machine learning sort of generated. So you mentioned that the first one is kind of like this smooth load cadence. They're not accumulating a high amount of load per step and they're not really accumulating a high amount of accumulative load. And then you mentioned the other one, which... is more about intensity, of higher impact per step. Is that right? Exactly. We have some opposite profiles, just like the first one you just said. The second one was the load step, low load per step. Is this guy with a high cadence, with low vertical oscillation. You'll see this, do you know this guy that you just look moving forward, not up and back, up and down. and a very smooth control. I will say these guys are kind of metronomists. They are quick, efficient, and they're precise. So they have good rhythm, they have good smoothness. The third profile, it's the moderate load per step. They have a low cadence and the moderate stiffness, a moderate impact. This group is the group that we usually suggest for a cadence increase. That's a group that biomechanically, and please don't say it's a rule, it's just a proposition based on the results. We didn't test it yet. That's one of our next studies. based on the biomechanical mindset, I would say this group would be the best group that would respond to a cadence retraining. The third group, the fourth group. is the high load per step. That's a group with extremely high vertical oscillation. It's like, do know this guy that usually run bouncing? It looks like it's running upward instead of forward, and they don't have a lot of time on the ground. They have a low duct factor, a low stance time. So they do a lot of force to accelerate upwards instead of accelerate forwards. So they have a huge impact because they have a lot of vertical ground reaction force. These guys, usually the guys that I see that respond really very when you say, hey, try to run without doing a lot of noise. Try to, you know, calmly try to do with not so loud. So usually they adapt the running without jumping and bouncing so much. And the fifth profile is the high cumulative load. They have a moderate ground reaction force, but they very stiff. Stiffness is just like how your leg acts as a spring. So every time we hit the ground, we have to absorb load, and we use this elastic energy to do the propulsion forward. So when you are very stiff, you have a lot of elastic energy, but you have a lot of impact as well. And when you have a... a high cadence, you have a lot of steps, really stiff. So it's a high cumulative loading. So you mentioned high cumulative forces in this particular profile. they also have a high impact force like per step? They have moderate peak forces. Yeah. So not as much load per step as someone who's traveling up and down at like a greater amplitude. Exactly. But as they have high stiffness, they can, instead of have a high, really high impact, they use a lot of elastic energy. That's how they absorb the impact. But still, it's not a low impact, but it's not so high, it's kind of moderate impact, but with a lot of steps. Right. So it's, I think it's important to mention there is no wrong way of running. Remember, all of those subjects, they were injury free for one near, so they have a lower epidemiology of injuries that we usually see in the literature. and they have performance. So they were recreational but injury free. So our study showed that it's possible to run different ways, but still get injury free. So how do you usually do this? Prepare your body to your biomechanical fingertip. instead of a one size fits all training, just like we see many times, and that's my critics. for some of the literature, they just select people with patellofemoral pain, just like knee pain, and they say, okay, we're gonna retrain the cadence of all of those subjects. So they treat every single runner with knee pain, just like a homogeneous group, and they are not. So when you try to identify the movement profile, just have a scenario when you can see, this guy run like this. So maybe his body is not prepared to deal with this kind of overload. So that's what I usually say. There is just like some myths in running, like biomechanical analysis. I don't need to do a biomechanical analysis because I have a good running profile. No, come on guys. Biomechanical analysis is not for saying you run in a good way or bad way. It's to identify the kind of overload your body is dealing with. So when you have a specific running, uh, uh, by our workloads, we can propose specific training that your body gonna need to be prepared for. And I suppose it throws a little bit more complexity into this scenario when looking at someone who is injured and maybe it's changing how they're running based on that injury. Because like you say, these 79 runners were Healthy uninjured for, you know, a year up to a year and the way they're running is kind of their natural rhythm. And so you can easily slot these runners into certain profiles to be like, this is how you're naturally moving through space. But if someone is injured or has been managing an injury for quite some time, maybe they've slightly changed how they run to move some load away from their knee. However, it's a little bit less natural for them. So maybe there is some added complexities there for someone who is listening to this podcast and is currently running with an injury or managing an injury or with some pain, some symptoms. you agree with that? I think it's one possibility. just, every time I did my PhD developing a sensor to help people to have feedback during the retraining process. So how can we deal with all of these variables just like we develop something that you have in your cell phone. And that's nice because a lot of people do this. change their way voluntarily, involuntarily, just like to protect the joint that's hurting, that they have pain. So the only thing that I always try to remind people is there is no better way of running. Every time when you change your movement profile, you just change the places where you have the overload. Just like when you have a rear foot strike, when you land with your heel, usually the knee is the joint that's most responsible for load absorption. When you change for a forefoot strike, just like when you land with the forefoot, it's not better. You may decrease the impact, but impact is just part of the forces that come into the body. And then you increase a lot the impact on the foot bones, just like the metatarsals. And you increase a lot the overload on the Achilles tendon on your calf. So what I usually see, I remember in 2011 when this paper from Daniel Lieberman and Arine Davis came out and they showed the paper published on Nature. And it's pretty good paper, really nice paper. And they show that people that don't use, that has never used shows, they usually run a barefoot way. They run barefoot for the whole life. They usually strike with the forefoot. And they showed that these kind of people, have lower impactive forces. And what happened? A lot of people... translated this, showing this. So there is lower impactive forces, there is a lower injury. And if there is a lower injury, I'm gonna change my way of running. And a lot of people, mainly here in Brazil, we have just kind of boom of people changing from one day to the next day, the way they're running. And what happened? A lot of people with knee pain, decreased the knee pain. That's really nice. On the other hand, a lot of people that had not. ankle pain, achilles tendonopathy, they develop cough injuries. It's not because it's wrong, because just try to figure it out. You have been doing a movement during your whole life and then suddenly you change. every time when I give some lectures around the world about this, I use as an example the Michael Jordan app. You remember that Michael Jordan, the basketball player, when he retired for the first time, what he wanted to do? to be a baseball player. And he went to play baseball and he was a horrible baseball player in the beginning because he was very fit, but for basketball techniques. He didn't have the body prepared for the baseball skills. So despite his skill for the basketball issues, he didn't have the skills for the baseball, he had to train for it. It's the same when you say, when we... Translating to running is the same when you try to change your running profile, the running mechanic. That's not wrong. Just make sure you, you give time to your body to adapt and prepare your body to this new profile. So this way you don't just get recovered from one injury and get injured in the other part. Right. And so thanks for illustrating that point. The paper title when it. When it says, is there an ideal profile for minimizing mechanical overload? What would your answer be based on what this study found? We found that our research supports the idea that one size fits all approach to running biomechanics and injury prevention. Maybe it's not so effective. So there is no one best way of running. There is no best way of. You can run in many different ways. That's why we started doing with healthy people. Because we have now more than three, that's the next study we are ongoing. We have one study now with 3,000 runners. And from these 3,000 runners, we have most of them with some pain. Hip pain, knee pain, ankle pain, foot pain, low back pain. So... Okay, we're gonna find some different profiles and all gonna be the same as the injury-free subjects. But the point is, we start with injury-free subjects to show that it's possible to run in many different ways without getting injured. So maybe that's how we deal with injury. It's kind of scale. You have on one side, the demand imposed on your body and this demand is made by your volume and intensity of training, the mechanical overload of your running, your sleep quality, your nutrition, your many different ways that impact on your performance. And on the other side, you have the ability of your body to deal with this demand. So it's just like you have to balance this. So of course, what people usually do when they get injured, they reduce the amount of training. So your scale just balance to the quality of your capacity. But what usually people say, okay, now you don't have more pain because you stopped running and rehabilitate you. So go back running slowly. And then you go 5K, 7K, 10K, and then suddenly start hurting again. And then what do you do? You say, Oh my God, I have to stop it again. And then you do the process all over again. And I know a lot of people that at end of the day, they just heard from the doctors, from the physical therapists, on the coats, hey, maybe your body is not made for running. So come on, guys, there is no way. There is no way. That's just, we didn't have the ability to discover what caused the unbalancing of these things. Maybe your... Maybe your biomechanics is not wrong, but you don't have the physical and functional abilities to deal with these kind of loads. Maybe it's not about biomechanics, maybe your sleep quality, your nutrition, your anxiety, and many other factors. So biomechanics is kind of one piece of the puzzle, but it's the piece that gives you the mechanical overload you have on your body. So I can say, hey, brody, you have a biomechanical profile with a lot of stiffness. So you have to train your body to absorb the loading and to deal with this kind of elastic energy that you have to generate. And we know that the elastic energy, most of the elastic energy, it's related to the ankle, Achilles tendon. So I can prescribe you some specific exercises to make your body prepared for this kind of running. And then I think that's the ability to tailor the training without need to obligatorily change the profile of movement. You can change the profile. That's okay. I love doing this. I love doing the cadence retraining, impact retraining. I usually, that's the only me. It's not wrong, but I usually don't like to do a heel strike or foot strike retraining. But impact retraining, cadence retraining, usually do, it's an option, but it's not obligatory. Gotcha. So let's just say I have someone who has a long history of knee pain. Every time they return to running, they start developing symptoms. so step one, we would have to analyze, okay, how are you returning to running? What is that approach looking like? it, are they just jumping back into it too much? their volume increased too abrupt? Uh, we look at their sleep. We look at their nutrition. We look at their other rehab elements that they might be doing. Uh, then we've covered all those bases. They're being gradual with their reintroduction and they're still the injury itself is still being quite stubborn. Uh, it seems like the next step would be, okay, let's just analyze how this person is actually moving, what their biomechanics is doing, and maybe put them into one of these five profile. buckets, and then based on how they naturally move through space, we can then tailor some advice to them. So if they are, maybe it is adjusting their cadence, or maybe it is trying to give them a different cue as to, you know, let's just imagine you have a roof over your head and you're just trying not to jump up and down as high because that ceiling is very low or try to impact the ground softer or try to keep your chest up or like different cues based on how we would expect them to respond positively based on the profile that they have found themselves in. Would that be the next step? It's one of the possible steps indeed. It's like this, this profiling is just part of our biomechanical assessment. Just like we do this profiling and we analyze all the coordination. That's one paper we just published in June of Biomechanics, the coordination of the body and how is different between men and women. And I think one nice thing for the listeners is we have to understand that knee pain, it's not just like, it might not be a knee problem. Sometimes you have a hip problem, sometimes you have an ankle problem and the knee is the joint that's hurting. Maybe you don't have to strengthen your knee or stretch your knee muscles. Maybe the hip is weak and your knee is just being overloaded. So what we usually do is discovering if we have some weakness and some specific biomechanics profiles, just like you have a lot of pelvic drop, you have a lot of full aversion, and how can we prepare the body for this. And after this, if we don't have good results, Or maybe you can do both. You can do both similar ways. My point is, both from my clinical experience and scientific experience, there's no right way of dealing with ninjas. I know a lot of people that they are really good at changing the biomechanical ways of running, just like you just said. And I love this. And I love this because it works. The only problem of changing biomechanics is that the runner has to cooperate. because you cannot keep the high volume intensity while you're training for the new movements. Because we know that for the first four to six weeks, you have, independently of the way you're changing, if you change the movement of some runner, you decrease the running economy. So they spend more energy for doing the same running. So if you keep your high volume and high intensity as usual training, maybe you can... even increasing the cadence, you can increase the risk of injury. So if you have a runner that cooperates, just like you say, hey man, you have to decrease your volume for three to four weeks for 50%, just one month down, and then you go up again. If you have someone who cooperates, that's perfect. But we know that not everybody just gonna do this. So for this one that I know that won't... would not be so cooperative. I usually prefer as a first option not to change the biomechanics. But usually I try to educate the runner. Say 50 % of the runners get injured every year. So you have one into two chances of getting injury. So if you try to do more than what we are saying, you increase your likelihood. If you don't, you still have a high likelihood. So you have to do it in a proper way. And if you'll tell me when your first pain starts, we can change some variables, then do not allow the pain to progress. So it's kind of just like we say now there's pain education and just like it's injury education. I try to explain to my runner what happens. Say, and every time you get injured, you increase the likelihood of a new injury by three times. So it's not about not getting injury. It's preventing future injuries, not getting injury now. So every time you respect your body, every time just like you respect your body, you respect your future during running. And I love saying this to subjects because it just let the impression that it's not our responsibility as professional or only our professional. It's a shared responsibility with the runner to do this and to prevent injuries and to avoid, uh, stop running. Yeah. Well said. think because it's such a common experience for someone to train for a marathon, get injured halfway through their training, go to see a health professional and the health professional says, okay, you got injured when you're running. Let's have a look at how you run. They have a look at them on the treadmill and say, Oh yeah, your cadence is too low. Um, impacting with your heel too hard, posture is slightly off. You need to make these changes and then you'll feel better. Um, and so they're sort of like jumping to changing their biomechanics is like the initial, um, intervention where it seems like the first point of call is, okay, let's look at your training volume. How are you building this up? How is your recovery to sort of match the buildup in training load? And the change in biomechanics should come later. Once we've covered all of our bases, like you said, you wouldn't change initially. It probably later on, once there's clinical justification for a few reasons. One, if you change how you run, you're spending a couple of weeks being mechanically inefficient because your body just isn't trained to move through space that way. You're overriding what might be your default way of running. And so that comes at a energy cost. And so you're becoming less efficient, but also to your point, we're not reducing the overall load on the body. We're just redirecting it somewhere else. So we might theoretically redirect load away from your injured site, but you're increasing a load somewhere else. Something's got to give. And we just want to be very careful that if we do end up making that clinical justification of changing someone's running pattern. Uh, that wherever that load goes, the structures can best handle it because then you're going to develop another injury. And I have seen people transition to barefoot shoes or to forefoot running way too quickly. develop foot stress fractures. They develop Achilles tendinopathies, calf strains, all of those things, um, because it has been too abrupt. maybe if we go back to that person training for the marathon, that example. Maybe it wasn't your biomechanics at all. Maybe a biomechanics is just fine. Uh, it was just the training load preparing for a marathon. Maybe just weren't prepared to get into that training cycle. Maybe just weren't strong enough, or maybe that jump was a bit too abrupt. And so it could be very easy for people to say, I got injured when running something must be off. Maybe I have, maybe I'm pronating too much, or maybe I'm, you know, favoring one side. And so people can easily go down that rabbit hole. But I think that's a pretty key takeaway that you're highlighting there. I thought it'd be good to reemphasize that. Yeah, that's exactly how I think. In our running program here, when we rehabilitate and when we train, we have a lot of runners in our clinic. We have a program with three layers of intervention. We call the acute, subacute and chronic layer. The acute layer is the changing the training variables. So how can we train, change the volume, the intensity, the frequency? How can we adapt initially by controlling the training variables? Because it's acute. So sometimes you're even more tired one week and the amount of training was too much for your body this week. It was not about your biomechanics, it was not your shows that's not working anymore. It's not about your... Socks, know, there is only one single variable. No, sometimes just you're not up to running so much this week. So that's okay. Let's rest one week and then we come back this next week. It's not stop running, but maybe we try to reduce 20 % of the volume this week and then we go up. We'll have usually four months to train for a marathon, three to four months at least. So that's why we hope it. You know, that's, that's the first layer. The second layer is the neuromuscular training. I love strength training, but I do love as well, neuromuscular training because- Is this in the subacute section? Yeah, that's the subacute section. Exactly. So I love strength training. We know that strength training help reducing injuries, but usually what we know as well, that's the highest muscle forces during running. It's about 30 to 40 % of the maximum force. So you don't use the amount of force just like close to your maximum amount of force, just like when doing a squat with a maximum weight. You don't need to be a bodybuilder to run. So sometimes, of course, you have to be strong. But most important of all, you have to use this strength during the movement. You have to activate your muscles properly. You have to have good coordination of the muscles. So I love training the muscles coordination during the running. And that's our second strategy. And that's what we do. Sometimes you have a iliopisoas, that's the anterior tight muscles guys, the anterior tight muscles tight. And when you see someone running, you don't see he is doing a good propulsion. And then you say, okay. I can change the biomechanics, but why don't I do some stretching of the iliopsoas and then I train to activate the gluteus to help him, to give him the ability to do this propulsion. And when you increase the propulsion by the hip, you decrease the amount of load on the ankle. Because if you don't have a good hip strength, your ankle, your triceps, your calf, gonna compensate it. And we have a lot of subjects with ankle pain. not because of the ankle, they have really strong calves, they have really flexible tights, but at the end of the day, they don't have a good hip muscles. So they compensate down there. And that's the subacute layer. And then the third layer, the chronic layer, it's the mechanical head education. And the mechanical head education, that's what you said. You have to decrease the volume because... Otherwise, you're going to increase the risk of an injury instead of reduce it. I usually for beginners, when we are treating beginners, I love doing retraining just from the beginning. If you have a low cadence with a high impact force for beginners, for all of those, I do cadence retraining. Because we know that beginners have two, three times higher injury likelihood. than training the subjects. So, and as they don't have a high volume, that's okay, they can deal with this because it's not a mechanical failure they have. They have a respiratory failure, just like they cannot breathe anymore. So they stop running because they are tired, not because they have muscle weakness. So I feel very comfortable to change the mechanics of beginners. But when you're talking about someone that's running for three to four years, has five marathons, some experience, his body is adapted to, and then suddenly he starts to have injuries. So why this guy didn't have injuries for the past five years and then now it's now his mechanic? That's the mechanics, you know? I don't know. I don't know. I really don't believe in this kind of thing. Of course, when you say, know 20 years later, okay, you're getting old. So your way of running change when you get older. But when you say five years difference, you don't have a really great difference just like that might justify it. At least we don't have, for most of the people, we don't have data to prove this. So I usually don't use this movement retraining for this kind of runner, because this kind of runner usually You know, he has, he in Brazil, it's really usual now. Now we are in the middle of the year and next week we have the highest marathon of South America. It's the Rio de Janeiro marathon. have more than 70,000 subjects running. It's huge. It's huge. And you know, this guy that's going to run the marathon, three weeks later, he has another one and three months later, he has another test. So. Usually they don't want to stop running or reducing the volume. it's usually I only do movement retraining, but already when the guy cannot run anymore and say, okay, I'm giving up because I, as you said, I tried everything and nothing, nothing helped me. Okay. So come we can try this, this strategy now. What advice would you have for recreational runners who are listening to this? And now aware of the paper and the findings. Like, do you want them to learn where they fit in these movement profiles or is there any other practical takeaways you might suggest for them based on this paper? Yeah. The first one, the first one is don't chase a universal perfect form of running. So, uh, you don't need to force your body into someone else's running style. Instead. Run smarter by learning what your body is already trying to tell you. And that's what we call functional biomechanics. It's understanding how your biomechanics is telling you your body is working and prepare your body to do it. Of course, this paper we are presenting here is just the first attempt of looking at these variables. But in a few years, I can assure you, we can come back to this day and you can... You can tell me, say, you said that on this day that we now have a lot of gadgets. have a lot of, you know, we'll have a lot of wearables now that we're going to be able to collect this data while you are running. And they're going to tell you by your watch, are going to tell you by your phone, say, hey, you are now in an increased risk. Be aware, control your training, talk to your coach. So. The first, the most important thing that I would say is don't chase a perfect way of running. Respect your body. Probably if you run for a long time, your body has adapted and has a good mechanical profile for yourself. So just be aware to get yourself prepared for your own mechanical way of running. Right. And one other question I thought I'd throw at you just before we wrap things up. Why do you think I wrote down a couple of answers? Well, I think, but why do you think people do run differently? Why do you think there are these different movement profiles? Um, because I often, it's so funny, like I'll watch birds fly. I'll watch dogs run. I'll watch all these animals run and they, they all do the same thing. Then I go to the park and I see people running and everyone just runs so differently. And it's crazy how we as a species can't just run the same, like all the other animals out there, but I was thinking, okay, what are the variables? think maybe height. Like we know some research shows that taller runners have a more efficient with a lower cadence. So height might be one of it, flexibility, mobility, stiffness, strength, um, like certain genetic makeup makes certain people have stiffer tendons that make them more able to propel or be, be stiff. Um, maybe the shoes that people wear. like all the shoes that they gravitate towards might change them a little bit of how they prefer to run. Like, do you have anything on top of that? Anything to add or anything to disagree with in terms of why people run so differently? No, I think exactly you have my answer because it's, there's a lot of variables that can influence this previous experience in different sports, just like we know that three athletes. They run completely different from marathon athletes, mainly because they usually run after cycling on 180 K after an Ironman. So of course they have just like a curved posture when then you go running, you have to be more upright. So there are so many different variables and it's difficult to say, oh, that's the variables that matters. We don't know. To be honest, we don't know. If we did the answer, we wouldn't have so many injuries until now. So what we do, we try to control what we have discovered so far. So we know that, of course, your anthropometry, just like the size of your body influences. We know that shows influence the way of running. There is no good and bad shows. OK, that's not the issue here. But you have your strength, your... flexibility, your previous experiences, the terrain you were running, how tired you are. So many variables influence. That's why I always say, don't try to control every variable because you just get so obsessed for this that you just forget what you are running for. Having fun, healthy, just having fun and go running. Of course, prepare yourself. just like you're gonna do, I'm pretty sure. That's interesting because usually people do some cardiological tests if they feel some palpitation or if they have some, know, usually people just do some tests after they have the initial symptom. So what I usually say people is prevent, work on prevention. Do your biomechanical analysis. Look for your coach. If you don't have on your city or your country a good biomechanical lab that can help you with quantitative data, be sure that your coach has a lot of experience that can see you running, they can record you with his cell phone, and can just give a lot of tips for you what can he does for help you train better and have good performance and decrease the risk of injury. That's how I usually deal with these here with my runners. Yeah. And a good takeaway to wrap things up. Gustavo, thank you for conducting this study and bringing it to our attention. I know a lot of work goes into these things, but also thanks for sharing the paper. I know you also not only shared the paper with me, but also linked to a YouTube video that had these different profiles and that for people to check out. So I will include that in the show notes if people are interested in learning more. I will also include your Instagram handle if people want to learn more about you. You did say I was in Portuguese, but there is a translation to convert it to English. Any other key takeaways before we sign off? Well, no, I think it was pretty good. I'm pretty happy with the invitation. Thank you, Brada. Thank you for paying attention for our study. It's really nice to be here to talk with a lot of people that will come here, listen to you, for thousand people that come listen. I hope that my participation just put some more ingredients on your audience here so they start paying attention for some issues that maybe they are not paying attention. At least they don't get so obsessed for looking, chasing the perfect way of running and say, hey. No worry guys, you can run differently without getting injury. Just prepare yourself and have fun. Yeah. And it sounds like you have some very interesting studies coming up that you're looking to conduct and gather some information on that. So I'll be watching closely on your work. And like I say, thanks for all the work you do and thanks for coming onto the podcast. If you are looking for more resources to run smarter. or you'd like to jump on a free 20 minute injury chat with me, then click on the resources link in the show notes. There you'll find a link to schedule a call plus free resources like my very popular injury prevention five day course. You'll also find the Run Smarter book and ways you can access my ever growing treasure trove of running research papers. Thanks once again for joining me and well done on prioritizing your running wisdom.