All right, well, thanks, Ed, and as you mentioned, we're going to talk about their early sports specialization today. There are my disclosures. And I first want to start off by thanking Ed for the invite. I get to be a part of this rock star lineup. I have Lynn's not here, I don't think, but she's someone that I want to model my career after. And Ed's got this journal flying like this, Dr. Axe is one of the guys I used to read all of his papers when I was little, and then Tim, I was kind of a closet admirer from across the globe. So your work I love. So it's an amazing honor to be up here with everybody and Matt and Mark as well, and Lindsey. But I also want to mention Dr. Michele. He didn't tell all the stories about strength and resistance training and all in my career. He's set up a lot of the things that we know and what we do for training young athletes. And this is Avery Fagenbaum, when he was trying to train and do max testing and do resistance training with kids. That was a no-go 40 years ago, and Dr. Michele signed off on it. So it was a big deal, and that changed the trajectory of what we do and how we train kids now. So we owe him a big gratitude and thanks, and I couldn't attend his honor last month at ACSM, but I got these from Stacy. He hasn't even seen these pictures yet. His admin likes me better than him, I think. But I got these pictures from Stacy, but he was honored last week. But what I'm here to talk to you about is a sports specialization, and just so we get on the same page of what we're talking about, it's some form of one of these things with year-round training, participation on multiple teams of the same sport, choosing a single or main sport, and quitting all other sports to focus on one sport. So it can be some derivative. What we're primarily talking about, most athletes are going to specialize at some time in their career, but this is talking about athletes that specialize earlier in their career. So to get on the same page, who in here would say it's okay for all athletes to specialize early whenever they want? Who's kind of of that opinion? Does anybody like that? Anybody think it's okay part of the time? There's some cases where it makes sense. In general, pretty much against it, I want to keep multi-sport athletes. We'll talk about it and see what we think about that after we move through this. But primarily, there's a lot of talk on sports specialization and other factors from the burnout and other things. But I'm going to focus on two areas, underdeveloped neuromuscular coordination and impaired athletic development. These are the areas where I'm going to focus my talk on today. There are some empirical data out there that suggests that multiple sport athletes, they can maintain it. The longer they can maintain it, the better they can perform. This is some NBA data indicating that some of the players perform better and have less missed games from injury. Not a prospective study, but some evidence. This is my colleague, Dr. Neeru Jayanthi, he's probably one of the world leaders on sports specialization. He's been looking at this for many years. We found out that there's a lot of youth sports specialization models that are not really caring about the health effects for the young athletes. We have about 60 million kids playing sports now, and about a third of them are early specializers. I think the one thing that I'm not going to talk a lot about today, but a lot of kids don't know what their best sport is because we don't have a lot of sport in PE, they're not sampling. These kids choose early because their parents take them down that pathway. They've never tried the sport which may be their best sport. That's one of my biggest problems with early sports specialization beyond some of the other things we're going to talk about. To frame this up, we like to talk about the ACL injuries in the female athlete. I'm going to talk to you and frame a lot of the early sports specialization in this model. It can apply to many different models, but we're going to talk about a developmental model of ACL injury in the female athlete. We talked a little bit about this, Mark did, as far as the developmental aspects. This is a study where we looked at vertical jump height, so that raw power over different Tanner stages, from Tanner stage two through five. What you see on here is males, each successive Tanner stage, as they mature, they get more powerful. They jump higher. What do you see on the females? They jump as high as they're ever going to jump at puberty. They're not getting more powerful. What happens to females? Mark showed us everything that happens. They get taller, more mass. Basically what we're doing is, without any of this extra neuromuscular training or strength training, we're giving these females a bigger car, but not giving them a bigger engine. Is that a problem? How does that propagate? Here's one of our young athletes. We did a longitudinal study doing her jump landing test. You can see her knees, they look pretty good as she's doing her drop landing. There's her three years of testing. None of you guys have a biomechanics lab, but can anyone tell me if she's jumping or landing any different at post-puberty? See how her knees look like a hinge, like they're supposed to at pre-puberty? Now they look like a ball and socket. This is how it might propagate. Why is that a problem? In this same cohort, we followed these athletes and looked at their landing mechanics. We found that those frontal plane and transverse plane loading mechanics tended to identify an athlete that was going to go on to this type of an ACL injury. Why does that matter, and why do we care about that during development? From our perspective, we talked about that frontal plane loading, and Dr. Michele talked about that ham quadrature, so that posterior chain load. That's our ACL friend, so that's an important area. We also know that the lack of trunk and core control is a problem, and that asymmetry when landing I think is a big problem. Those all together multiply and put an athlete at high risk. Here's a young athlete, not highly skilled. She's demonstrating all those mechanics we just talked about, that knee abduction load, loss of trunk control, more weight on one leg, and it gives out. She's a young athlete. This is Cynthia Barbosa, so she's one of the top athletes, she's one of the top high school players we ever had in the United States. She's got a lot of those same mechanics. You see she comes with it, lands with it, jumps off with a nice valgus load, loses trunk control, lands on a single leg, so those mechanics. She survived, but those mechanics that propagate when she's specialized were a problem potentially. This is a study looking at the mechanics that are related to ACL injury. They're also related to some of the mechanics that we see in young athletes with patellar femoral pain. The difference is the relative load, that frontal plane load for anterior knee pain is much lower and it's in younger kids. Basically, it doesn't take as much of a threshold to incite that patellar femoral pain. My question to you, if you have that young athlete coming into you in the clinic and she's got anterior knee pain and she's raising her hand, hey, when I grow up, I'm going to be at risk for an ACL injury because she's going to get bigger and have more load and more mass and that knee abduction load will increase accordingly. From a sports specialization standpoint, we showed that the more specialized athletes have a higher propensity for this anterior knee pain and the incidence of injury. We have some epidemiological data out there. How does sports specialization relate to this and looking at the mechanics? This is a study, we had about a thousand kids, over a thousand kids looking at their sports specialization status. What we did is a cross-sectional study with this one. What we found is about 183 in each group that were either pre- to mid-pubertal that were highly specialized and then the same that were unspecialized and then we had two post-pubertal groups that were the same type of match. What we found, we were looking at joint coordination, so the ability to couple the hip and knee in an appropriate fashion when landing from a jump. We found that the highly specialized had an altered hip coordination, hip-knee coordination that we felt was related to unstable landings, like you see here, that lack of hip control is driving the inefficient force absorption on the landing and that was more evident in the highly specialized and the post-pubertal athletes. That same data set, we really wanted to focus on that transition from pre-pubertal to pubertal through to post-pubertal. We had a data set, took that data set and only looked at those athletes that transitioned that were highly specialized. The transition in that period, the transition from puberty to post-puberty and then we had a group of unspecialized athletes, so we compared two groups. In that cohort, what we found is that the highly specialized athletes, the girls naturally increase their knee abduction load as they mature, primarily a matter of increased mass, but we found that those that specialized had larger increases in that knee abduction moment and they started to move away from using that sagittal plane moment that we want, that nice frontal and quad and hip sagittal plane. That was what we found in that cohort. One of the biggest knocks on our research is we sit around in our laboratories and play with these athletes and they say, oh, that's a sterile environment, that has nothing to do with sports. What we did to overcome that is we developed a sports specific virtual reality environment, so where our athletes could be in the lab, we could test their biomechanics, but they compete against avatars and we can measure their biomechanics. This is one of our two tasks and we've shown that that VR scenario tends to increase those risk factors, so we can measure them with a potentially more sport relation. This is one of our header tasks, so what we have is a corner kick where the ball is going to fly to the athlete and they're going to compete against the goalie to get the ball in. Here's an example of the header task. What we did with this is we wanted to look at differences in gross body movement. This was just looking at center of gravity of the athlete, so we weren't looking at all of the individual biomechanics, but we were using a sample entropy approach where we wanted to see how that athlete performed and how they maintained their function with the sample entropy measures. What we found in this study, again, this was a very small data set, but the specialized athletes tend to demonstrate reduced movement complexity, so when they're competing against the avatar, the avatar has different variations in how it responds to it. The specialized athletes tend to perform in a very robust way, so when they're performing their skill, they were very repeatable, so we'll talk about what that means, but we felt like that could be reflective of they may have less ability to respond to a perturbation in those types of things, and we'll talk about that a little bit more. We also have a VR cutting task, and the way this task works is you run at a player with a ball, and once you get into close enough proximity, they'll randomly kick the ball one direction or the other, so you have to respond to the avatar and the kick to try to play defense on the ball. Again, we're using some fancy statistics, so don't question me on this cross-recurrence analysis, but basically, we wanted to see, we looked at two phases of the jump, the run-up phase and the cut, and it's deceleration phase, and looking at this cross-recurrence analysis, and basically what it means is looking in the cross-recurrence analysis, you're looking for mean diagonal line, which is basically the knees are always doing the same thing all the time, and the trapping time, meaning that the knee appears to be kind of stuck in that type of a movement as it goes, and what we found is, again, the highly specialized athletes tend to demonstrate greater coordination, so they were good at the task. The sports, the soccer athletes that we're specialized at, they had good coordination and they performed the task well, but they had reduced ability to intentionally respond, so whenever the avatar was changing things, they didn't respond as well, and we'll talk about what that means, so from a perspective of what we talked about, the female athletes having that frontal plane load that we think is high risk that you see here, and this is what we see in general training, so an athlete having their generalized training, and consider those bar plots, that knee abduction load when they're training, so whenever I'm training athletes, this is how much I'm going to expose them to that high knee abduction load. We think that that black swan event up at the top right, that's when they tear their ACL, so that's taking them in loads that we can't train them in, and that's whenever they have that unexpected black swan event. Here's our theory, here's what we think what happens with sports specialization, so we're training them in that window, so they have better, they're very robust to a general training, they're robust in training, in accepting and decelerating that knee abduction load. When we specialize athletes, they become more robust, they become more coordinated and very strong in that particular movement and can handle those loads, but what we've done is we've shrunk the window to that outside area where the perturbations come, so those unknown loads that push them up, and so the idea is a specialized athlete may have a bigger window to have that black swan event or that perturbation that takes them over the top, and so the idea is we need to move away from training highly, overly specialized and optimized athletes where we want them to be able to handle those unpredictable loads and train and be able to efficiently move but absorb those unavoidable perturbations. So Tim, this wasn't even put in there, this was in my talks previously, so I'm not putting that in there, but the one thing I want to add to Tim's quote here is we use the injury prevention, he made a point that you don't sell to coaches based on injury prevention, I'm making the point that we can't do injury prevention where we're always trying to keep them out of that high risk position. We have to train them in those high risk position and be able to tolerate it, and I think that's where people have been missing the mark on training. So this takes us to some of our work, I worked with Adam Kiefer on this and the idea of creating an anti-fragile athlete, can we make an athlete that's beyond resiliency but actually anti-fragile which means they get stronger when exposed to the bad things. So again, we're going to keep framing this in the idea of that knee abduction being a bad thing. So does anybody know the story of King Maitre D's? So the story of that is his son, he was becoming very powerful and the father didn't like it so the mom told the son that his dad was going to kill him with poison. So to prepare for that he started taking small doses of the poison to protect himself for whenever his dad was going to give him the big dose and that protected him. So it's the idea of hormesis where you're taking some of the bad to get the good. And this is the basic principle of our vaccines, that we weaken them. There's a point where it can make sense. But I can tell you, just to give you a real life situation, I love drinking beer. So for me, from a hormesa standpoint, you would think that the more beer you drink, the better. So if you kind of lay it out, more beer, good. That's what Greg thinks. Well, here's kind of my Greg when I start drinking. I get to about that 0.07, 0.08, I start to get better looking. I mean, I get good looking. And then about 1%, this clicker, I start to get smarter, too. It's amazing. I become brilliant. And then about 1.2, I start to get stronger, too. And it's just amazing how well my beer drinking goes. But this is kind of my theory of how it is. But this is what the rest of the world sees. Here's my high school picture of what I actually look like and what people are seeing. But there is some limits to what you can do with hormesis for anti-fragility. So the concept that which does not kill us makes us stronger, that doesn't really apply in training. But you know me, I always think more is better. If a little bit is good, then I like more. So here I have my athlete jumping off a Bosu, landing on an Air X. And I go, man, I'm getting some great gains out. This is awesome. You know what I should do? I should use two Air Xs. So I get one of my lab guys. I say, try two Air Xs. That was not a good idea. So there are some limits to how you apply this. And again, it's the same idea with vaccine. We wouldn't give a strong dosage of the virus when we're trying to vaccinate. So there's some sort of a sweet spot when having exposure to the bad. So again, I'm going to keep framing it on this valgus load to give you a theoretical principle. How would we train our athletes? So is this a good dosage for my athlete? Because she earned the right to have a bar on her. I'm basically adding resistance and hardwiring her to do the bad mechanics that I want. So that's where I consider a harmful dose. What about this? So do some jump landing. This looks real good. I just took my dose even again. This is a bad dose. I'm not getting the effect that I want. Here I almost took the dose too far. She about tore ACL during training. And that's bad PR. You're doing your injury prevention training, and you send them home with a ACL injury. So that's, again, an even further harmful dose. And then we got too complicated here. And the guy tore his ACL during training. So there is limits to how we do this. But I do think that there's ways that you can expose the athlete to some of the bad. So here she's doing her RDLs. She's working on her control. She's not perfect, but she's stressing the system. So this is potentially a sweet spot for that athlete to be doing her training. What about this? And she's doing her heel touches. This could be OK. She's not terrible, but she's dropping that knee in way too far. And I think she's potentially doing more harm than good. So I think she's in a spot of diminishing return. She's getting stronger, but she's not training that away. So maybe we take her off of that box. And look how her hip alignment got a lot better when we took away some of the stability. And she's really working on stressing that. Another thing you can do is actually pull them into knee abduction. And they'll fire up their glute meat in their glutes to actually resist that. So that's another way where we're actually giving them a dosage of the bad to help them overcome what they need to do. So what are the strategies to prevent over-optimization? So we did a training study to see if there was a way that we could actually do this. And this is, again, some of Adam Kiefer and I's work looking on creating this anti-fragile athlete. And the idea is we want to see if we could increase that ability of the neuromuscular system to be responsive to that unexpected perturbation. So what we did is eight weeks of neuromuscular training versus the normal off-season activities. But what was different about this training is that we added progressively different perturbations and reaction. And it was really focused on, away from our normal training, it was focused on these unexpected perturbations that train the athlete throughout the time. And so we pre- and post-tested them with a drop vertical jump. And then we did EMG on the glute meat was our outcome measure. And again, as I mentioned, we can continue to ramp up on that unexpected nature and potentially giving them more exposure to the bad and the knee abduction load with the training to see if that would help with tolerating. So what we did was our outcome is we wanted to look at that EMG 100 milliseconds prior to the landing. So we're trying to see that muscle tonus. And by tonus, we mean that rapid activity that's anticipatory for the landing. Because after landing, we get a lot more different biomechanics, and it's driven by the load. But we want to see what the athlete would do in that preparation for that disruption. So we did an auto-recurrence analysis where we took that 100 milliseconds and plotted it out. And we're looking for percent laminarity and determinism. Again, some more fancy stats. But basically, laminarity means how stuck you are in that movement pattern. So how stuck we would think the EMG would be versus the percent determinism, where this set of EMG or this millisecond predicts the next millisecond. So both of these we consider bad or not responsive to the type of training. And what we found is the neuromuscular training with these unexpected perturbations, we had both reductions in the laminarity and determinism. So you tend to be less stuck in that movement pattern and not overly predictable. So how do you explain that in layman's terms? So the way I describe that is the no training group, if you think about water, and it's very calm, one drop goes into and it creates a huge disruption, just one little drop of water. Where if you have this tonus, this rapid muscle activity and an unpredictable muscle activity, if you had to have a perturbation or if it has that excitatory membrane, one drop doesn't disrupt it. Many drops doesn't change it much. So the idea is having that rapid and excitable muscular system. So we talked a little bit about this. It's a time when we've got to start these training programs again. When is it important so that we don't miss the opportunity for these key developmental growth phases with our athletes? So here's a young athlete where we're starting to teach him his kicking mechanics. And he's having some failures, but it's pretty low risk for us at this time. And it's a good learning opportunity. So I don't have a problem with the misses because I actually think he's learning motor skills and it's a good time for that. Now this, on the other hand, is a problem. I think we've already missed the opportunity. This is way too late. This looks funny, but that's pretty scary if that kid's motor control is that bad. And the question is, can youth even learn complex motor skills? Is it possible to teach them? Well, let's see if we can get to the next one. It'll come back one more, but watch this kid's play. So the answer is yes, you can train young kids and get pretty exciting adaptations. So I'm not going to talk about this, but Tim will talk about this. This is a paper we just published in Sports Health, so you can go read it. But he's going to talk about the different types of load response and whether an athlete is load naive or responsive to the training. So there's different types of load responses. And we're going to talk about that. Or responsive to the training. So there's different athletes and how you will measure that and assess that. But it's a great, great idea. But what I want to talk about a little bit related to that is the idea of increasing your training age. So we talk about what age do you start doing things with athletes. I don't base it on that. I base it on their training age. How many years has that kid been doing this type of training when they come into me? So if I have a 10-year-old that's been training with me for five years, they're going to be doing some high-load, high-demand activities and be able to do them well. If I have an 18-year-old that's never trained before, they're going to start where the 10-year-old did when they were five. So they have to build up that prerequisite skills. But this kind of builds back to the idea, if I train younger and have them where I can do high-load, high-demand activities at a younger age, then when they're getting all those things, all those androgens and those hormonal responses we see that Matt talked about, that that's the opportunity where we can really create good opportunities for these kids to grow and get stronger. This is another article in Sports Health. You can go read about it. But we talked about implementing these integrated neuromuscular training concepts. So we know that sports specialization is going to happen. We think that we can train these athletes and give them the tools that they're missing, that they are normally getting from other sports. And we think that's a good idea to do. But the big thing you have to think about and what we talked about, you have to train for that primal level of strength. Strength is our building block for everything else. If I have a kid that doesn't have that basic level of strength, neuromuscular control doesn't matter, because they can't carry the load anyway. So it doesn't matter. So primal strength is key, building motor skill. And then we can start to do that injury risk reduction. But those are our basic building blocks. The other question I get so sick of tired about is I don't train with sports specificity. I train athletes. So I train a female like I train a male. I try to take that athlete and make the best product I can and the safest product, the best performer, and give it to the skill coach. I don't do sport-specific training. There are some considerations that we talked with a long distance runner versus sprinter. There's some considerations on how you do that. But ultimately, we're going to try to let the athlete tell us what we do and give that coach the best product we can. So I want to take you through a few videos. You think this guy's specializing too early. I think so. This is way too early to be so focused on ping pong. But this guy I love. Just think we made all of our kids do pull-ups to watch cartoons. We would have none of the problems we have. But again, he started early with an additive resistance. Little Tommy's doing his pull-ups with the dog going by. Then as Lynn showed as well, this is a time to get little Timmy. He started putting his toys up at the top of the climbing wall, and you can motivate him to start doing his resistance training and motor skill development. So he can progress to more demanding tasks when we're early. And Dr. McKaylee hit the nail on the head. We can start training kids. When they have the cognitive ability to take instruction and perform, we can start doing these types of activities with young kids. So this is, how do I back this up? I missed. So this is my colleague, Dr. Neeru Jayanthi. So a lot of you don't know that Neeru and I grew up together. And this is Neeru. He wasn't into playing multiple sports. He's big into it now. But when he was little, he used to sit around and dump water in his underwear and dump water on his head, get in fights. And so he was not what we'd call a high-risk athlete. He didn't have any of those diverse motor skills. And so if you look at Neeru, my mom sent me this video because you knew I was talking about him. Look at Neeru's jumping and landing mechanics. And he's exactly the type of athlete we're trying to help. And it's not going. Let's see. These clickers ruin all my jokes. Look at his landing mechanics. Oh. That's a mechanical problem. Yeah. And then again, he studied way too late and became a problem. So again, that's why I've really pushed Neeru to get into the sports diversification now to solve these problems. So I'm going to send you home with a few take-home points. So we know that early sports specialization is going to happen. So some of that early evidence suggests that it's going to limit sports performance capacity. We think that multi-sport, especially earlier, younger athletes, is going to benefit them both on the performance side, and it can increase injury risk. And I think the one thing where the injury risk occurs is you have athletes, they continue to expose themselves. So they have a lot of similar exposures where they're putting themselves in that high-risk position. And I think that's the one concept we think about. And then as we showed with our data, athletes aren't prepared for that black swan event. So they're not as resilient to those unexpected perturbations. And then sports specialization is going to happen. So that's why we think we need a third of athletes that are early specializers, we need to get them involved in these integrative neuromuscular training, increase their injury resilience, and potentially their sport performance, and reduce that black swan event that we're all worried about. The one thing I want to mention to you again as clinicians, and physicians, and practitioners, we can't be part of the problem. I think that over-training, and specialization, and over-competition is a problem. I think under-use is a far bigger problem. And if you don't agree with me, you can argue with Tim. This is his paper. But I think this is a big area where we, I think we talk a lot about it, and over-training. But under-training is a much bigger issue in our society right now. And ultimately, we want to take these athletes and do long-term athletic developments. We don't have time to get into these models. Tim will probably get into this a little bit. But basically, we want to create models where we can do long-term athletic developmental models. So I'm going to close this out. You guys, again, don't have a 3D biomechanics lab. But can anyone see the early specializer at high risk for ACL injury in this picture? So she started, can anyone see her? Right there. When she went on to high school, she went on tour, had three ACL injuries. So this is exactly the type of athlete that we want to target with both these targeted trainings, but opportunities to improve their motor performance and skills. And again, if you take anything away, you don't have to fear the black swan anymore. So again, I want to thank my team. I get the opportunity to talk to you about all these cool studies. But it's really, I'm the dumbest guy on my team. I have a great team of people doing all the great work at Emory. We have a lot of physicians and physical therapists that work with us, as well, to make the science go. And those are my acknowledgments. And I thank you all for the opportunity. And again, before I end, I want to thank, the clap should go for Ed, because I think this journal has really become one of my favorite journals. And then when we put an article in Sports Health, we get a lot of exposure. So thank you for all your work. I see George and the other editors. Thank you all for your work. Thanks.

early sports specialization

strength and resistance training

sports specialization

neuromuscular coordination

athletic development

ACL injuries

injury risk reduction