Jared Powell:
Today's guest is Tim Gabit. Tim is a renowned sport scientist who has been working in elite sport for 30 plus years. Tim is a rare breed who has completed not one but two PhDs, which gives me severe trauma. Just thinking about it, Tim is known as the load management guy, having popularized the concept with his acute chronic workload ratio related work in the mid 2010s. These days, load management is everywhere, and everyone has an opinion on it, from coaches to players, to sports journalists, and even fans who may be a victim of load management.
Jared Powell:
Indirectly, when shelling out their hard earned cash to attend an expensive game, only to find their favorite player is being arrested. It's a polarizing concept and there are critics. I've brought Tim on the podcast to talk about load management, the acute chronic workload ratio, progressive overload in all that jazz, but also some common buzzwords associated with load management, such as resilience, robustness, and capacity, which get bandied around often these days. Tim has a common sense and practical approach to sport science, which makes his work so appealing to many, and he does a great job of distilling complicated ideas and theories into comprehensible and actionable strategies for coaches and clinicians to use to help their patients and athletes. Without any further delay, I bring to you my conversation with Tim Gabbett. Tim Gabbett, welcome to the show.
Tim Gabbett:
Thanks, Jared. Thanks for having me on.
Jared Powell:
No worries, mate. I've been wanting to talk to you for ages. I think we've been exchanging messages for years now trying to get this conversation happen, so I'm really pumped we can get a chance to do it. I've been reading your work really since I was a new grad, perhaps even a student, which is going back a long time. That ages me, Tim, it certainly ages, ages you, I'm afraid as well. But do you mind giving me Tim a a bit of an idea and also the listeners, a bit of an idea of your background professionally? I, I think I read that you've done not one PhD, but two PhDs, which makes me feel very inadequate, Tim. 'cause I'm struggling to finish my first one. Yeah, give us a, give us a brief background of your life story.
Tim Gabbett:
Y yeah. Well, I'm, I'm actually not that old, so when you say, you know, , what age is me? You know, I, I'm joking searching when I was 10, so I'm really only . Yeah. Look, I, you know, like most people involved in sport as a career, they, and they're involved in sport as an athlete, you know, so I, I was a pretty, pretty average sort of athlete. I, I anticipated in a lot, but I often, I often joked I would've done really well if I just had one fast twitch fiber . I had a real professional mindset and a real disciplined mindset to my training and, and competing. But I, you know, I just wasn't, wasn't fast enough, wasn't skillful enough. So I went into, into an area where I thought I could make a difference and, you know, I'm probably far better. I was far better off field than I ever was on it.
Tim Gabbett:
So when it came to working in sport, I just enjoyed helping coaches. I enjoy working with coaches and, and athletes and, and all of the, all the research I do just comes from questions. Sitting down with coaches and having a coffee with a coach and just actually listening to them when they're coaching and they throw questions at you all the time. Some of the time that they didn't realize they're throwing questions at you. But those questions just come from those conversations. That's really what's driven the research over the last 30 odd years basically, is what's a real world question that the coach is asking or the athlete's asking, and, and is there a way of trying to provide an answer to it or get closer to the answer?
Jared Powell:
Yeah, I think that's why your research has been really well received and popular, Tim, it's because it's seeking to answer practical, everyday questions. You know, it's not academically opaque, which some research can be. It's really, it's really practical. So I think it's interesting to hear that stems from real world everyday conversations with coaches who are on the front line. So that's cool. To
Tim Gabbett:
Me, that's probably the, the place where I'm most comfortable, to be honest. You know, I don't have, I don't have to dress up in a suit and tie. Very rarely do you, do I actually do that. If I have to go to a conference and I have to put a suit on, then I do it. I, I'm not particularly comfortable in that environment. I'm much, much more comfortable just getting out in my, in my football shorts and, and san shoes and just standing on a bit of grass or, or in a weight room and, and just, you know, the conversations are pretty cool because they can go anywhere and the good coaches, they know the right, they know the right questions to ask are, you know, the, the best coaches that I've work with, they'll just, they won't say much, but then occasionally they'll throw you a bone and they'll say, oh, see this right here, and they're pointing to something that's happening in practice. See this right here, that's important to us. And then, you know, okay, well that's something that I can really focus in on and see if I can provide an answer, you know, around why it's working or why it's not working. What are the things that make it successful? What are the things that make it break down under pressure? So they're the kind of, yeah, that's the, that's the stuff I really like doing.
Jared Powell:
And is your background sports science? Is that right? Yeah,
Tim Gabbett:
I started in strength and conditioning and then just as, as jobs evolved, I've moved more into, into sports science. I was, was kinda straddling science and strength and conditioning probably before either, either of them really were entrenched in sport, you know, so sports science was, was only really in the state institute and Academy of Sports in the Olympic sports. Professional sports didn't really have a sports scientist. And even then strength and conditioning coaches for professional sports, they weren't necessarily highly qualified. They were just, if you were the fittest former player, you ended up being the strength and conditioning coach of a professional team. So it was in those early days where you were kind of wearing a, a number of hats and certainly with the, the teams I worked with early on that we just never had the staff to be solely specialized in one particular area. So you, you'd go from strapping ankles to laying some cones out to run a run a warmup, and then you, you might be doing a little bit of skills coaching, you're doing some conditioning, you know, so there was, and then you're, you're doing some analysis of the session, whether it be just quantifying training loads with pen and paper, you know, and then doing some analysis after the session. So it was a different time, you know, everything was first principles, but it was pretty cool. Yeah,
Jared Powell:
Exposure to proper on the frontline as a trainer, as a physio, as a sports scientist, as an SNC guy, that's a cool apprenticeship. You know, these days hotshot sports scientists come out, dunno how to strap an ankle probably, you know, or they're, they're very good at data and Excel spreadsheets or whatever it may be. And perhaps that sort of basic first principle stuff, as you mentioned is lacking that it must be interesting for you to sort of watch that evolution over time.
Tim Gabbett:
Yeah, well look, if I the one thing I am so glad that I had was that apprenticeship, the first ever job that I had was with a third grade rugby league competition. You know, what it allowed me to do is to make a lot of mistakes at a low level where the stakes weren't as high. And then, you know, I spent a lot of time in those lower levels wearing a number of different hats. And to me that was, that was the best apprenticeship I could have because, you know, the team were just happy to have someone who was committed to 'em. If you go straight from your degree into, into an elite level job, the reality is you, you don't really know a lot. You know, what you've been taught in a degree, but for the most part, the degree is just a ticket.
Tim Gabbett:
It's, it's not nine tenths of what you learn there is you have to kind of forget and relearn what's important in a, in a sport. Whereas, so when I've gone through that, that lower levels and made my mistakes, when I got to the higher levels, I felt like, okay, I've spent my time at these lower levels, I've earned the right to be here now. So when things inevitably go wrong, and they always do, you always, you lose two or three games in a row or you get a, a bad run of injuries, then you really, you learn some things about your apprenticeship and, and what you can fall back on and, but you also learn a lot about other people's apprenticeship and, and when they get a bit nervous and they start looking sideways, going, somebody say something, somebody, I dunno what to do now.
Tim Gabbett:
Whereas if you've been through that with your own team at a lower level or you know, you've just had a, a few more experiences to, to lean on, it's, there's a bit more calmness. You, you kind of, you go back to, okay, well let's, let's just focus on what's really important here. Let's focus on on the things that we know are gonna get us outta this, this patch. But if you haven't got that experience, yeah, I, that's one thing that I I think is a shame in the current system with people going out of uni straight into a high, high performance job. I, I really worry for 'em because it, you know, you need some good people around you to make sure it works. Mm-Hmm.
Jared Powell:
Yeah, for sure. What does your current professional life look like? Tim?
Tim Gabbett:
I work with, with different, different organizations, different high performance organizations. So it could be an institute or an academy of sport, or it could be a professional team or it could be a circus or a dance organization or the military. So I, I work with a number of different high performance organizations and the questions that they, they'll come with their own unique questions that they want answers to. You know, it, it could be, let's think for a, for an institute or academy of sports, how do we get as many, as many of our athletes onto the national team? And then once they're on the national team, how do we get as many of them on the podium? For a military organization, it could be, well, how do we deal with low entry standards? So we, we've got recruits coming in and the entry standards aren't as tough as they once were.
Tim Gabbett:
So, so they're breaking basic training and there's no way they're gonna cope with exercise when they have to go out for 10 days out in the, on exercise in the field or in dancers. How do they, how do we make sure that our dancers go from the show being darker or in off season, you know, the equivalent of an off season, they're coming in and coping with six hour, six hour days and multiple different shows, rehearsing for multiple different shows at the same time. How do we, how do we deal that, deal with that? How do we plan that out? How do we make sure that we don't break them? So there's, there's a whole heap of different questions. Essentially. It's all around performance though. It's, it's around how do we, how do we get the best performance for our particular athlete and dancers, they might call themselves artists, but they're, they do athletic tasks, soldiers or special ops. They're athletes in their own right. The performance is what we're after though. We want to try and maintain really high levels of performance and keep those athletes as healthy as possible getting
Jared Powell:
There. Do you work with athletes and coaches on an individual level or more at the sort of organizational level?
Tim Gabbett:
Yeah, yeah, both. So for example some of the work we've done is with the northern mystics in New Zealand, and there are, there are an elite level netball team. And so most, most of the work that I do with them will be with the head coach and then depending on, on her needs and what, where she sees some, some gaps in the program. It might, it might involve filtering down to work with different staff members as well. You know, at times it's, it's working with individual players within a team. So it might be different players who just have to learn how to win a session. You know, they're, they're in that elite program, but they just, it's, it's kind of bridging the gap between happy to be in the team and this willingness to, to win, you know, to be there to win. So there's, there's some, you know, even at an elite level of ice levels of sport, there's, there's people who are just happy to be in the team and then there's ones who just do not wanna lose.
Tim Gabbett:
Mm. So how do you make, how do you make those ones that are just happy to be in the team, the ones that you, that you can really depend on when the game's on the line. So helping them to win a session is, is a big thing for me is 'cause a lot of them, you know, even at the elite level, haven't learned how to train properly. They haven't learned how to control their brain in, in some of those hard moments. And, and some of them, some of them give into themselves a little bit, not intentionally, it just happens. So they've just gotta learn how to, how to recognize those moments and fight through those moments to, to get the result for them individually, which then impacts the team.
Jared Powell:
This is slightly off topic, but I wanna ask you, have you watched the recent Olympics much pay close attention to it and all the, there's a bit of talk about the training methods of certain athletes versus training methods of other athletes, specifically the Norwegian method, which is really popular amongst triathletes and some middle and long distance runners and their, their star athlete. Inger, Brison just got fourth in the 1500 lost to some of his nemesis, Josh Kerr specifically, and Cole Hocker who won it. Everyone's saying it's the death of the Norwegian method. Anyway, just wondering if you've got any opinions on all of these things and in track and field, given the, given that we've just finished a really good Olympics, I thoroughly enjoyed the, the Paris Olympics.
Tim Gabbett:
Yeah, I watched a, a lot of the Olympics and I, I probably, because of my background in, in running from a young age, I probably, I get into the track events a bit more and, and I like the distance events. Most people see it as just, you know, who's, who's got the most fitness or, and there's, there's no, it's not like a team sport where you have tactics, but it's such a tactical event when you know what you're, what you're looking for. There's, there's a lot of, lot of tactics in there. You don't wanna get boxed in, you've gotta make sure that, and the gap between making you run too early and too late is, is quite small. There's just this window where if you get boxed in, you could go from sitting comfortably at second or third spot on the inside rail to, to finish in eighth or ninth.
Tim Gabbett:
It's, it's that tight. I'd have to ask you what, what the Norwegian method is, because if your understanding of the Norwegian method might, might differ from what I understand it to be, but for me, I, I liked some of the, the mental aspect that, that athletes are more comfortable talking about now. You know, we've, in the last 10 years we're, we've talked a lot more. It's been encouraged, it's accepted that you can talk about mental health and you know, in the past it used to be, you know, you just never talked about it. It was never, never a thing, it was never acknowledged. I think most people now are, they're looking at mental health and say, well, if you are, if your athlete's not healthy, then they're not gonna have capacity to perform well. So, but I also like, you know, hearing about someone like Jess Fox when she's, when she's lining up, she knows, she knows that she's gotta, she's gotta put together a really good run.
Tim Gabbett:
And she said there's nothing better than when the pressure is really high that you are at your calmest and then you manage to pull it together. Everything's calm, everything's quiet when, when the pressure is really high. That to me is being able to control all those things that are swirling around in your brain and just, just pull it all together to, to come up with a, the physical output that she, she does, but there's such a big link between the physical and the brain. Simone Biles is another one for me. She's had such a, a challenging life from a, from a really early age, and then mm-hmm, , she went through, you know, that significant trauma in Tokyo. She's got the, the twisties
Jared Powell:
Got the twisties. Yeah.
Tim Gabbett:
I imagine, you know, doing that many spins, getting that high in the air and not knowing whether you are going to land on your feet or your head, and then to overcome that produce what she produced. Like to me, these are athletes that have got extreme, extreme resilience. They're just the mental strength that they've got to be able to come out and compete. That to me is what I really admire.
Jared Powell:
Yeah, and I'll throw Inga Britton into that as well. He came back from his fourth in the 1500 to win the 5,000 after the huge disappointment of, of that. And I thought that showed tremendous bravery and sort of mental fortitude as well. And all the Olympians, I mean, we can't even begin to relate to how formidable they are physically and psychologically often. And yeah, huge respect for the Olympians. I saw a ridiculous survey, Tim, that says that 25% of Britain's believe that they could become an Olympian if they started training today for a particular event. And even more ridiculously, I think it was like 20% of 18 to 24 year olds reckon they could compete at the 2028 Olympics in the a hundred meter sprint. If they started training today, they reckon they can just go out and start running nine to 10 seconds. It's mad. Being an Olympian, particularly in the track is crazy. Tim, I can run a 5K in about 23 minutes. They're doing it in 12 to 13. Could
Tim Gabbett:
We say that's an example of the Dunning Kruger effect? Yeah,
Jared Powell:
Like
Tim Gabbett:
To me that that is probably highlights how oblivious 25% of that population are because like, you know, it just takes so much, so much consistency. Yeah. There's a discipline that comes with it and then there's a consistency and, and the vast majority of people just don't have either, you know, like there's a single minded focus about it. Yeah. Like, and people talk about, oh, well the Olympics is once every four years. It's, it's not once every four years. It's every day for four years. And yeah, I, I mean I, it's funny we can laugh about it because we just know just through seeing the really good athletes, the way they, the way they train, the way they prepare. Yeah. Those 25% of people are kid themselves.
Jared Powell:
Yeah, well, especially if you do a sport that is in the Olympics, and I think running is a really good example. So I encourage every person who thinks they can to go out and run a 5K and see how hard it is. If you break 30 minutes and you haven't run much, you've done really, really well. These guys are doing it in, in 12 to 13 minutes, which is just exceptional. They're running well over 20 kilometers per hour. Marathon runners are running at 20 kilometers per hour for 40 2K, which is astonishing. Anyway, we could chat about sport all day. Tim, I want to talk to you about load management. All right, so inverted commas no one can see, but I'm doing inverted commas, load load management. You can talk about the history of the term in a bit. So you've got a reputation as being the load management guy. Certainly a lot of your work is focused on load management, and this inc includes the acute chronic workload ratio, which you published on a decade ago now and are still publishing on. What, what do you make of the rise in continued rise? It seems of load management. It's certainly entered the public consciousness now. Most people have an opinion on it, including sports fans, journalists, commentators, players themselves, coaches, scientists, it's everywhere. People know of it. It's, it's, it's in that cultural zeitgeist. It's not an obscure sports science term anymore. What do you make of the rise and rise and rise of it? Are you responsible for it, Tim? Is it all your fault? Give us a bit of a narrative on that.
Tim Gabbett:
Well, the, the term load management, I'd never used that term before I'd been to the states, but when I got to the states, people were using it. So as far as I can see, it has been used in different physiotherapy papers where load management was used to bring someone back from, from some sort of surgery. So that was part of the rehab load management. And essentially in, in that, in that es in, in that respect, it is about if, if we're going to load the athlete, which we know we're going to do to bring them back, we just have to manage the response to that. You know, if, can we manage, we, we need to make sure that we don't overload them by, by loading too quickly. But we, we need to make sure that we don't under load them either and leave them under prepared for when they do return to sport.
Tim Gabbett:
So that, that was where it's mostly been used in a research sense in physiotherapy papers and that then I went to the states, I guess it was most commonly used in, in the NBA sphere, and my understanding was that there was a team who strategically rested some players in the lead up to the playoffs to try and get them doing well in playoffs. And they might have, they might have done well in the playoffs, they might have, may have even won the NBA championship that year. And, and I think load management has probably been equated with rest in the NBA. If you, if you hear the NBA's comments on load management as, as far as I can see, reading, reading between the lines. I think what they're talking about is rest. I think what they're talking about is sitting players out. When I talk about load management, that's not what I'm talking, what I'm talking about is using training principles.
Tim Gabbett:
These are well-established training principles to get our, our athletes, whatever the sport, whatever the, the task that they're doing to get them achieving great performances, the, the best performance possible and getting them there as safely as possible. So we're, we're talking about progressive overload and progressive overload isn't rest, it's, it's the opposite of rest. It's, it's about doing a little bit more than what you currently can do. So that's a principle of training. We're talking about specificity, we're talking about individuality, that the load you can handle might be completely different from the load I can handle. If you take someone away from load long enough, then you're going to lose the ability to handle load. So reversibility, variation in training, having highs and lows within your training. And then, and then recovery is a principle of training, but you notice it's, it's not the whole puzzle.
Tim Gabbett:
There's a whole heap of other principles in there as well. So recovery is just, or rest is just one small piece of loan management. It's important. Recovery is important, but in, in, in my experience, the teams, the practitioners within the teams, they do a great job of using these principles to get their players competing as much as possible. And rest is the last lever they pull. They're not looking to sit players out all the time. If, if a player needs a, needs to be set, set out or needs some extra recovery, then it's typically they've, they've looked at a lot of other levers before that and it's kind of the last resort. We need to sit this player out. So I think part of it being taken up by social media or part of it being taken up by commentators is, you know, I think it's just, it's easy to slap load management on that rest sitting players out in my, in my mind, I'd prefer him just to say he's sitting the player out, he's having a rest because it's, it's not actually load management, but yeah, I can't control what what, how people use the term.
Tim Gabbett:
It's, it's up to them how they use it.
Jared Powell:
Yeah. Load management sounds much more technical than he's having a rest. Tim, LeBron James is sitting out because he is tired versus LeBron James is sitting out because of load management. It makes like their sports science team seem far more, far more accomplished and scientifically rigorous versus is just a bit tired.
Tim Gabbett:
Yeah, it's, you know, there's, it's a sophisticated term. Mm-Hmm. Highly educated if you can use the term load management rather.
Jared Powell:
So let's go. So Tim, what's the acute chronic workload ratio? Can you talk me through what this term means and its history and its rise to prominence?
Tim Gabbett:
All the acute chronic workload ratio is an example of progressive overload and it's, it's a way to progress your loads relative to your capacity. And, and we know that progressive overload is one way to improve capacity. It's not the only way, but it's one way you can do it. We know that if you can load a little bit more than your current capacity, it causes your capacity to arise, which allows you to load a little bit more, which then allows your capacity to rise again. The trick with progressive overload is you want that load to be just slightly greater than your current capacity, not have massive increases in load relative to your capacity. So a little bit is good, but if you do too much, it increases the risk of the tissue breaking down. So, so the acute chronic workload ratio kind of tries to capture load and capacity.
Tim Gabbett:
So the chronic component, the denominator, chronic cap, chronic load is, is like your capacity score. It's the, the consistency of your loading, it's what you've been able to do on a, a regular basis. And the idea is that if you've been able to handle something on a regular basis, then a little bit more than that can be your acute load. It's the load that you apply to rise to, to cause your chronic, your chronic load and your capacity to rise. Acute load is, is just your short term load. What you've done in a session or a a week and chronic load is just the, the load that you've done over a longer period of time. And it might be three or four weeks, it could be longer for, for an endurance sport like a, a marathon runner. But essentially what we're trying to look at is what is the size of the acute load, the load that you're about to give your athlete relative to what they've been prepared for over a longer period of time. What's the size of acute load relative to the chronic load
Jared Powell:
And the ratio? What, what are the numbers? What's the sweet spot that you've published on
Tim Gabbett:
When you, when you calculate a ratio, all it, all it is is takes you take the, the acute load, the the most recent load and you divide that by the chronic load and that will give you a ratio. If you had a, a ratio of 2.0, what that would say is that the load that you've done today or this week is double what you've been prepared for over the last four weeks. If you're unloading your athlete, then you might have a ratio of 0.5. So what that means is the load that you've done this week is half of what you've been prepared for over a longer period of time. Now when we, when we took three Australian sports, we found a JS shaped relationship between the acute chronic ratio and injury risk. So there was low risk at low ratios around 0.8 to 1.3 as the risk of injury, as the, the ratio increased. So the higher the ratio, the faster we ramped up loads the risk of injury went up. Now keep in mind that's, that's three Australian sports. It's not every sport that's that's ever been known to man.
Jared Powell:
Was this a FL cricket rugby,
Tim Gabbett:
Right? Yeah, that's right. Three, yeah, Aussie rules, cricket, rugby league,
Jared Powell:
And sweet spot of those three sports in the data that you analyzed was 0.8 to 1.3, was it? That's
Tim Gabbett:
Right.
Jared Powell:
Yep. Cool. Again, cricket, rugby league, Australian rules, football. Cool. Any other sports where the acute chronic workload ratio has been analyzed now and and does it pretty injury as tightly as as it did in those?
Tim Gabbett:
Okay, well it's, it's been analyzed in a lot of different sports actually. So if you look at tennis and soccer and American football, basketball, I think there's about, you know, in a systematic review we did recently, I think there was, I don't know, 10 or 12 different sports where they'd looked at the acute chronic work workload ratio and injury risk. And as the acute chronic workload ratio increased, as load was ramped up faster risk of injury went up. And I think it was 90% of those papers at the time showed a consistent finding. You know, there was like, now when you say does it predict injury, that's something that I would say it doesn't do. And if you, even, if you go back a step to the, the three sports that, that we looked at the, the r squared between acute chronic workload ratio and injury risk.
Tim Gabbett:
So the explanation of how much does acute chronic workload ratio explain injury, it was only 54%, right? So there's a couple of ways you can look at that. You can say, okay, 54%, that's a big Rock q chronic workload ratio is pretty important. The other way you can look at it is you say, well if 54% is explained by the q chronic workload ratio, that means that 46% is explained by something else. You can only put into your model what you've measured. So we know there's gonna be other variables that are going to contribute to injury risk. We know that injury is multifactor or they occurred due to a whole heap of different risks. What it says is that the way you ramp up loads is pretty important, but there's also going to be other variables. The acute chronic workload ratio is not gonna explain everything that occurs in injury. But again, you can only put into a model, a statistical model, the things that you measure and, and some of these things you just, not all teams measure 'em, you know that they're there, you know, they exist, you know, they're probably important. That's about as far as you can speculated around what those potential risk factors are. Yeah,
Jared Powell:
Tim, does the acute chronic workload ratio mean that you can only increase your weekly load or weekly volume by 10%? Does it, I know you published on this, does it tightly constrain greater improvements than say 10 to 20% per week? Or is there more variation in that?
Tim Gabbett:
No, I, there's times, okay, firstly, there's times within a season, let's say you're going to a double, triple overtime game, chances are your loads are gonna spike. So it could be that your, your acute chronic workload ratio is well over 1.5, so what do I do there? Do I shut all my athletes down because they've all go gone over 1.5 or do I think a little deeper about it and say, well, you know, maybe some athletes can handle this better than others. Equally, there's gonna be times in a pre-season where I'm gonna intentionally, functionally overreach my athletes and that might take them over a value over acute chronic ratio, 1.5. Now, I, I don't do that on day one of preseason. I do it as part of a plan. You have to earn your right to go through one of those shock blocks. Of course there's gonna be occasions where I do that, so no, no point in time would I say you have to stick between 0.8 and 1.3.
Tim Gabbett:
In fact, that green and red zone, the sweet spot and danger zone, if we go back to why it was actually put in place in the first place, it was so, so we could make science a little bit more accessible to the average person. And for people who've never interpreted a graph before, here's a way that you can look at this graph. This is kind of a, a safe zone here, but when you ramp up loads really quickly, risk goes up. You'll notice I haven't said rate goes up, I'm saying risk goes up. So what I'm saying is on average, it's not a great way to train for the average of, you know, a team of 30 players, it's your risk of injury will go up. But it doesn't mean that I can definitely identify which athlete's gonna break and it doesn't mean that all athletes are going to break.
Tim Gabbett:
So this is where I go, well, okay, well if I'm, if I'm prepared to take some athletes over 1.5 or the game just throws at them a double or triple overtime game where loads of spike, then how do I, how do I manage that? And that's, that's where I start thinking about what we call moderators. Moderators are just background qualities, background characteristics. Some of them have been documented and we know about, but again, there's probably some that we don't know about. The ones that have been documented are predominantly around team sports. And I'd say they probably differ from sport to sport and they probably differ from position to position and they probably differ between individuals within the same position. But we know there's certain moderators like age injury, history, training, history, lower body strength and aerobic fitness. Those five are five moderators that we know if you have them in place.
Tim Gabbett:
If you not particularly old or young, you're in the middle of your career, you've got a short injury history and because of that, you've got a good training history and 'cause of that, you're strong in your aerobically fit. There's five moderators if you've got that in place versus someone who doesn't have that in place and you've spiked workloads in both of those players. The only thing that's similar about those two players is the spike in workload. Everything else is different. So the way I manage this guy who's got everything working against him versus the, the guy who's, who's fit and strong and has a, a short injury history and he's been able to train regularly, I'm gonna manage him completely differently. The guy who's got the, the moderators in his favor, I might just wrap my arm around and say, geez, you're doing a good job. Keep going. You know, like just keep training the way you're train, you're doing really well. The other guy, I, I might have to be a little bit more cautious with him. I might have to manage him a little bit differently. I might have to promote a bit of recovery, I might have to reduce his training load a little bit because his response isn't an advantageous or a favorable response to a spike in lung.
Jared Powell:
Yeah. So that speaks the individuality and the nuance and the context of applying the acute chronic workload ratio to an individual based on those moderators. And that's, that's a really good way of thinking about it, everybody. And it's the same in in physio. We know that everybody can respond differently to a certain treatment. You know, there's gonna be some who get far better with a certain treatment, some who are unmoved and some that may even get worse to a certain treatment based on moderating baseline variables that might predict or be associated with a certain outcome. And it sounds like it's the same thing with training. We certainly know it's the same thing with strength and conditioning. You can give a similar stimulus to two different athletes and there might be two different strength responses. It's the same thing with aerobic training as well. You can give a similar, similar training program and there might be different changes in heart rate, VO two, max lactate threshold, whatever you want to measure. It's individual. And I think you made that point quite well. I wanna ask you Tim, capacity, you've mentioned a few times load, you've mentioned a few time, I just wanna get some definitions on these so the audience can sort of understand what you are talking about. When you talk about capacity, how do you define operationally capacity?
Tim Gabbett:
Well it's probably easier to, to describe load when we talk about load. We can talk about it in terms of external and internal load. So external load is the number of times you jump or the number of the distance that you run or the weight that you lift. That's external load. Now with that comes an internal, an internal response and we call that internal load. So if we're running our 5K, it could be the heart rate. What is your heart rate over a 5K run or what is your, your perceived effort over a 5K run? And when we talk about adaptation, the idea is that you can either run the site the same 5K distance at the same speed, but you have a lower heart rate indicating that you're adapting, you are adapting positively if you haven't haven't trained for a while and you go out and do the same 5K, maybe you produce the same speed, but your heart rate and perceived effort is through the roof.
Tim Gabbett:
That gives you an indication of capacity as well. Capacity for me is just the ability to handle of the tissue or the system to handle the load that you're applying to tolerate the load that you're applying. And we have different capacity tests. There's a whole range of capacity tests that give us a, an indication of system capacity. It could be a multi-stage fitness test or it, it could be a strength test that gives us a, an indication of system capacity. But you would have capacity tests that you use for the shoulder work you do, or you know, when we, when we're bringing someone back from a, a calf injury, you know, one of the, one of the capacity tests is, well, how many single leg heel raises can you do? And if we get to 20 to 25, then then we think and they're controlled and they're through a full range, then we think, okay, now we're ready to progress. We've, we've got a reasonable capacity of the calf, we've got capacity and, and we've got load. And essentially what we're trying to do is get an indication of the capacity of the tissue, whatever the tissue is, could be any, any tissue within the body. But we also wanna have an indication of kind of system capacity as well. And then we try and apply a load that's appropriate for that particular capacity
Jared Powell:
To hopefully progressively increase that capacity.
Tim Gabbett:
Yeah, yeah, I mean, and as I said, that's, that's one way that you can improve capacity through progressive overload, just load a little bit more than your athlete's current capacity. Yep,
Jared Powell:
Yep. Manipulating load to if, if it's, if it's the goal of somebody to progressively increase their capacity to get better at some outcome that they want to get better at. What, what about things like robustness and resilience, which I hear a lot about now as well. Are there differences between a certain capacity and being resilient or being robust? Yeah,
Tim Gabbett:
For me, I dunno how other people would define robustness and resilience, but I, I just define robustness is as can you, the ability to withstand the initial insult can you withstand the insult of running a 5K. That could be the robustness component, the resilience component of it is, well, can you run a 5K every second day or, or have you got the ability to run two 5K efforts back to back Monday, Tuesday and then have Wednesday off and then go Thursday, friday. Robustness and resilience can be, you can think about it in terms of an individual sport, a straight line running sport like, like running where predominantly you are, you are getting the same cyclical insult over and over again. Or you can think about it in terms of a multi-directional, multiple system sport like, like rugby or soccer where you have to change directions.
Tim Gabbett:
You have to, you have to accelerate, you have to decelerate, you have to, you have some body contact with different players. That insult comes in a lot of different directions comes at you from a, in a lot of different ways. So that's, that's a different type of resilience and robustness, but you're trying to, trying to bulletproof the body in either a single way or in multiple ways to handle the initial insult. That would be robustness for me and to be able to do it over and over again is resilience to be able to withstand the insult and then withstand it again.
Jared Powell:
No, I like that. Another word Tim, that's becoming more and more, I mean is anti-fragile, which is, which comes from economics and I think Naem Taleb, his book Anti-Fragile and it's, I think it's different in that colloquially, I think the best way to interpret it is there's an insult to your body or tissue or system. You sort of absorb that impact and perhaps, you know, things are diminished slightly. There might be some system wide inflammation or something which is normal in response to load you might need to recover, but then that stimulus increases capacity again. And now it's just progressive overload really when you think about it. Where you are, you're putting a controlled stimulus under the body and your body gets better for it and tale terms this anti-fragile, which is a different way to do it. It's kind of like when you think about vaccination, when you inject a little bit of the live virus into your system, your system responds to it and then you build up an immunity to it. Kind of the same sort of thing anyway. I don't think anti-fragile is gonna enter the, the public consciousness as capacity and all these terms have,
Tim Gabbett:
It might have already, but you know, that's, that's, to me that's, it sounds a lot like hand cello's general adaptation syndrome where I reduces stress and you might have a shock phase where initially you go backwards and you tolerate the stress and if you, if you continually expose yourself to that stress, then generally the positive adaptations turn to negatives. So that's why we introduced recovery into, into training programs. That's why over after a period of time you need to pull the stress away because the third, the third phase is in sease model is death. And we don't see death very often in, in exercise, but death in in that context is non-functional overreaching and, and over training. But it sounds like anti-fragile, the way you describe it sounds very much like general adaptation syndrome,
Jared Powell:
Agree alist stasis as well where you kind of, you you reach a new threshold of, of homeostasis, right? You, your body responds and then it changes in line with that stimulus. I think it's, it's an easy way to think about it. Anything else you want to talk about in regards to the acute chronic worth low ratio and how it's been interpreted or misinterpreted at large in society and sports science, et cetera, et cetera?
Tim Gabbett:
Look, I I think we've kind of covered, you know, like I, I think one is, I'd say that, you know, I think I've already said this, that it, it's, it's a variable that if you want to use it, you can use it and you don't wanna use it, then that's fine too. It, but it's, it's a way that you can progress load relative to capacity. But I've also said that it's only one variable, right? And both statistically it doesn't explain everything that occurs with injury. But if, if someone was to send me just raw acute chronic workload ratio value values and say, can you tell me what's happening here? Can you explain what I should do? The first thing I'd say is, well gimme some more information. What's the chronic load? Where are you in the season? Gimme some more context. I think if you just go on a graph and you say, well I'm gonna stick between 0.8 and 1.3 and never, never go outside those zones, then on average you'll probably keep your risk pretty low.
Tim Gabbett:
But on average you'll probably stay pretty ordinary as well. There's gonna be times where you have to push and there's gonna be times where you have to work a little harder and there's gonna be times where you're gonna need more information than just one variable, whatever that variable is. I, I just don't think, I don't think you could do it on one. You can't train effectively just using one variable. So yeah, if you, if you're loading your athlete, then you want to check the response to that load and if the, if the response is good. And you know, in general, if you, if you're loaded and you feel good in response to that load, it probably tells you that you're handling the load. Okay. And you can, you can load a little bit more and if you feel an excessive soreness or you're starting to your mood and, and you're starting to track down or you're starting to feel more stressed in response to training, then that might give you an indication that, that you're not tolerating the load as well as you'd like. And you might have to make some modifications to your training program
Jared Powell:
For sure. It's the acute chronic workload ratio is now, as you said, it's kind of taken on a life of its own. When theories get to this level, Tim criticisms tend to come at these theories. So it's kind of testament how popular your, your theory has become. Do you mind if we address a couple of criticisms and you can respond to Yeah,
Tim Gabbett:
Go ahead.
Jared Powell:
I think one criticism has been that there is a lack of evidence showing a causal relationship between training load and injury risk. How would you respond to this? Yeah,
Tim Gabbett:
I think, I don't think that's an acute chronic workload ratio issue. I, I think that's an issue with probably an issue with what we can actually measure and also how we can design projects. So let's, let's talk about the designer projects first. The vast majority of research that's been done on load and injury are observational and, and maybe there's been some associations between load and injury that have been found. But in order to, to know whether load training load is, is actually get a better indication of whether it's causing the injury, you would have to have a randomized control trial. And in my world that doesn't exist in elite sport. It's very rare that my coaches are going to say, yeah, yeah, go ahead, take half the group, they can train the way you think is, is appropriate. And then the other half of the group you wanna hold back and do an inappropriate training series.
Tim Gabbett:
It's, it's not gonna fly. That design is hard to do in sport. It's not, it's not impossible, but in elite sport it's just not something that, that I would consider, I would consider doing. 'cause We're just, the focus is on winning and if you think there's a better way to do it and there's a 50 50 chance that there's a better way of doing it, then the coach is gonna go down that path. The second challenge with that is around what we can measure. So in order for for us to know whether training load is definitely causing injury, we need to know what's happening at the tissue level. So at the moment we're kinda looking at a glo at a global measure of load and we're looking at, at injury and we're, we are making the assumption that the load that's been applied inappropriately has contributed injury risk.
Tim Gabbett:
But firstly our measurement of load is gross. At best we can put GPS units on a, on a player and we can measure how much distance they cover in, in high speed running, but we don't know anything that's, that's occurring at the tissue level. We, we don't know whether with a particular high speed running stimulus or sprint stimulus, we don't really know what's happened to individual athletes at the tissue level. We make some assumptions, we make assumptions that there might be some damage over a period of time or there might be some anatomical changes in terms of pelvic control, but they're all assumptions. And so we are not, we're not able to measure what's happened at the tissue level. We're only kind of inferring that if something happens at, if an injury occurs at the tissue level, that potentially it was due to what was the changes that occurred at the tissue level through things that we are measuring at a system level or in a, a very gross level. So there's some, some influences there and some links that perhaps we see this as what's happening, but we can't say for sure that one is causing the other. And until we can measure some of these things in the lab, but we can't really measure them well in the field, not at the moment. And until we can measure them in the field, I I don't think that we're, we're going to get any closer to causal relationships between load and injury.
Jared Powell:
Well said. Does the, and you mentioned this a moment ago or earlier in this chat, does the acute chronic chronic workload ratio accommodate tapering weeks appropriately? Because, because obviously tapering will change the acute acute chronic workload ratio by reducing the chronic load denominator. Yeah,
Tim Gabbett:
I I I think it does, you can load or you can unload relative to capacity using the acute chronic workload ratio. I think the criticism there is is around that we know a taper improves performance and some of the early research showed that when you reduce, when you go through rapid troughs in load, so big reductions in the acute chronic workload ratio, risk of injury seemed like it was increasing as well. So there was, people were having trouble, how, how do I marry up this information that on the one hand we're improving performance, but on the other hand, with the same reduction in load, we're actually increasing injury risk. And the reality is it, it was shown in the, in the first, in a few early studies, but if we took another 20 studies, it hasn't really been shown. The spike in load increasing injury risk is a pretty consistent theme.
Tim Gabbett:
It's, it's not happening in every study, but it's, it's reasonably consistent. I'd say a or nine times outta 10. That's what you see. The reduction in load, the big trough in load isn't something that's a consistent finding. It's, it's probably been shown maybe four times outta 20 and it was in the earlier studies, it hasn't really been consistently shown since. So I think that's probably where that criticism has come from. But the best that we could explain those early findings was perhaps it wasn't the trough in load, the reduction load that was causing the problem. It was that when athletes were coming back after the trough in load, there was, it was usually followed by a big spike in load. So it wasn't actually the trough in load, the, the taper that caused the injury risk. It was the spiking load that followed it. But as, as I said that it's just not a consistent finding, I would say, you know, only 20% of studies have shown that a taper is associated with an increased risk.
Jared Powell:
Cool. You've, you've touched on this already. Is acute training load consistently associated with an increased injury risk? You said maybe eight or nine times out of 10 It is. When, isn't it, and in what sports is that and how do you explain that?
Tim Gabbett:
There's probably the, the key thing here is when we talk about risk, if you were to, to take your athlete into, into these higher acute current workload ratios, let's say we get to a ratio of 2.0, we're doubling what they're being prepared for. The risk of injury there is around 20%. So there's, there's two things you could do there. You could race to the coach and you could shut that athlete down because, you know, we've, we've spiked his loads, his risk of injury is 20%, or, or you could think twice before doing nothing because if it, if there's 20% chance that they're going to get injured, that means there's 80% chance that they won't get injured, right? So yes, the risk of injury has gone up, but there's still a much greater chance that they're gonna be fine. The, the real the interesting thing for me is more, yes, acute on average, when we spike loads on average risk of injury will go up.
Tim Gabbett:
But in some athletes, risk of injury doesn't change. And then in other athletes, the risk of injury is really high when they're theoretically in the sweet spot. You know. So for me it's, it's not so much defining that risk of injury goes up on average. That's, that's kind of what you'd expect when you ramp up loads much greater than someone's capacity. The thing that's more interesting for me is what is it that separates the robust from the fragile athlete? Why is it that we can spike this athlete's loads and his risk of injury stays really low? And what is it about this athlete who's theoretically in the sweet spot and his risk of injury is 10 times greater? And that, that comes back to the moderators. The moderators, if you've got them in place, if you've got these, these things that are like protective factors, it's like a dimmer switch on a light that when you spike loads, it turns the, the risk down.
Tim Gabbett:
But if you don't have those moderators in place, the dimmer switch turns the brightness up and it turns the risk up. So that's, that's how, you know, I think a lot of people go, well, I spiked loads and I didn't get injured. Well, that makes sense. That's not an unusual finding because the risk of injury is still only 20%. Right. There's 80% chance you're gonna get, you're gonna stay injury free. The reason why you might stay injury free is because of these extra moderators. You're either in the middle of your career, you've got a short injury history, you've got a good training history, you're strong and you're fit. Yes, we've spiked loads, but you've got all of these other things working in your favor to protect you.
Jared Powell:
Yeah. So do you think that's where it's been, perhaps misinterpreted where people have equated or conflated increased risk with guaranteed you're going to get injured?
Tim Gabbett:
I've had conversations with support staff in high level teams and them telling the coach, you know, when we go to this ratio, you are 20 times more likely to get injured. And then I've had to pull 'em up and say, actually no, no, it's not 20 times, it's the risk is 20%. And they, there's different things here, right? Because what we're talking about is absolute and relative risk. And the absolute risk is not 20 times. It's, it's about four times. The absolute risk is 20% and 20% is not the same as 20 times. There's little unique things like that, and I think, you know, for, for every person that digs into the research, they'll see the graph and they'll go, okay, this is where I've gotta stay. Right. But that's a, that's a snapshot in time as well. You know, like that graph is a, is kinda like at the end of the year when we've summarized all our data, this were how it looked.
Tim Gabbett:
But what happens when you, when you apply a training load in a sensible way, that curve shifts to the right. Right. So, so now you can, it might look the same, it might have the same J shape, but the risk comes at a, a higher ratio, same risk that you can, you hit it at a higher ratio or at the same ratio, your risk is even lower now if you don't train, the curve shifts the left. So the risk comes a lot earlier at a, at a lower ratio. So it's in a graph that's in a paper, it's stagnant, it's like this point in time. But when we train, we're constantly trying to shift that curve to the right to, to reduce risk at the same load or produce to handle more load before we get to that risk.
Jared Powell:
Do you view injury as a complex phenomenon? Meaning it's kind of unpredictable in who's going to get injured and, and who's not. I know you've got your moderating baseline variables that may help predict, but at its essence, is it complex sort of unpredictable phenomenon where anything can happen on the day because there's so many interacting forces which can emerge and result in this, this outcome of becoming injured or developing pain, whatever that means?
Tim Gabbett:
Absolutely. Yeah. And my, my views on that haven't changed at all. I would say, I would say training load is in the mix, and that's probably something that we can manage pretty well. That's, let's say two hours, two to four hours of our athletes a day. And then we've got another 20 to 22 hours where the athlete is away from us living their own life, dealing with their own stresses, recovering the way they decide they're gonna recover, eat and sleep and drink the way they wanna fuel themselves. So there's a whole heap of uncontrollable stuff in there as well. So ab absolutely, there's, if you ask me or can predict an injury before it happens, I can say hand on heart with 100% accuracy that I cannot predict an injury before it happens.
Jared Powell:
Yeah. You, you can have hypotheses, right? That, you know, this person perhaps is more likely, but we're, we're not gonna take the next step and go, if you train this person today at this intensity, that person is going to get injured. But that's, that's, that's beyond the realms of what we can do with the scientific approach to injury. Yeah,
Tim Gabbett:
Well look, there's some people who, who believe that you can predict injuries now and there's some people who believe that we'll be able to predict injuries with, you know, artificial intelligence in the future. I don't think we'll be able to do it in my lifetime. And if I'm wrong, I'm wrong. I don't really, I don't really mind either way, but it's, it's just predicting an injury before it happened. It doesn't take a lot up. A lot of my time. I'm kind of more focused on, well, what do I need to do to put a good program in place? What are the demands of this athlete's sports? What are the physical qualities that this athlete needs to have in place in order to perform those demands? And then on an individual basis, what is it that, that Jared needs? You know, he's, he's got all of these physical qualities, but this is one that's letting him down. Alright, so we need to target this a little bit. We need to strengthen area. I, I've got a lot more faith in my ability to put a good program in place to develop a robust and resilient athlete with a good mindset towards attacking the work and, and getting after the work than I do at predicting an injury before they happen. It's not, it's not something I worry about. Yep.
Jared Powell:
Cool. What I need as an athlete, Tim is a, a VO two max of 70 please. And that I'll be, I'll be happy , because right now, mate, I'm getting way too gassed with these little five to 10 K runs that I'm doing and I'm seeing your runs that you put up on Strava and it, it's unbelievable mate. I don't know how you're doing all this mileage.
Tim Gabbett:
Yeah, it's it's consistency and it's just hard work, you know, that like covid was, was really kind to me. 'cause I, I actually had a lot more time to train. So I, I took my 5K time down from mid twenties. I've hit 18 minutes now. Whether I can do it again, whether I've got the resilience to do it, to back it up with another one. I don't know, it's just a little challenge for me to, to try and put a good program in place to, to get as much outta myself as possible.
Jared Powell:
So how do you train? Are you doing, do you do long runs? You dispersed with sort of threshold sessions or high intensity sessions? What's your principle with getting your 5K down, just getting fitter and doing it over a long period of time? No,
Tim Gabbett:
I mean, I, it's one thing to be fit enough to run a 5K, but then it's another thing to, to run those individual ks fast enough. Yeah.
Jared Powell:
You've gotta be fast. Yeah.
Tim Gabbett:
So, you know, in order to, in order to be fast, you, you've gotta do some speed work. So, and speed work for a 5K runner is, is different from a, from a team sport or a, you know, a hundred meter runner of course. But on the fast days, generally there's short efforts with longer rest. And then I'll, I'll do a VO two day, which, which is longer efforts with shorter rest, but then that might make up five to 10% of my overall running volume. The rest is kinda low intensity work. Cool.
Jared Powell:
I think you could talk for another hour on that, Tim, but I'm conscious of your time. I might let you let you go. Final thoughts on load management, acute chronic work workload ratio. Where do we, where do we go in the future? Are you working on anything interesting at the moment?
Tim Gabbett:
Oh look, there's always, there's always projects out there and when they when they come to the fruition, I'll, I'll release 'em. There's different projects for, for different sports. You know, the, the best questions come from the sports that I work with that far more great questions come from there than, and you'll find this yourself. Far better questions come from your patients and working with patients than they do from, from a lot of the research articles. I'm not a, the kind of guy who's super, you know, has to be planning everything in advance as well, you know, so I, I can pivot a little bit when it comes to if something new comes along or something interesting comes along, I'll, I'll delve into that for a while. So I'm just happy to keep working away at what I'm doing and help the coaches and athletes I'm working with and then see what comes from there.
Jared Powell:
Cool. Mate, are you on, you're on Instagram, are you on the, what other, where can people find you on the socials?
Tim Gabbett:
Yeah, it's a bit of a mess at the moment, isn't it? With social media? Yeah. Look at Insta. I normally put either training tips or, or different papers on, on Instagram or, you know, we have a Facebook page and, and LinkedIn. So they're probably the three places. But, you know, if people are interested in getting in touch, it's prob probably the website's the easiest one. Just go to gat performance.com and we'll get back in touch with 'em if they've they've got any specific questions.
Jared Powell:
Cool. Tim Gabit, thank you very much.
Tim Gabbett:
Thanks Jared.
Jared Powell:
Thank you for listening to this episode of the Shoulder Physio podcast with Tim Gabbett. If you want more information about today's episode, check out our show [email protected]. If you liked what you heard today, don't forget to follow and subscribe on your podcast player of choice and leave a rating or review. It really helps the show reach more people. Thanks for listening. I'll chat to you soon. The Shoulder Physio podcast would like to acknowledge that this episode was recorded from the lands of the Ang people. I also acknowledge the traditional custodians of the lands on which each of you are living, learning, and working from every day. I pay my respects to elders past, present, and emerging, and celebrate the diversity of Aboriginal and Torres Strait Islander peoples and their ongoing cultures and connections to the lands and waters of Australia.
