How To Optimize Your MMA Training Week To Perform Best w/ Dr. Chris Kirk (SSOF Ep 93)

Dr. Chris Kirk0:22

Now these things are fairly easy to measure in quite a few sports. So track and field, for instance—dead easy to measure external load. It's how far have you got the athletes to run, how many times have they thrown the javelin, how many times have they done a jump. And again, the internal response to those is fairly easy to measure. You can measure heart rate, you can measure lactate, you can measure muscle response. Really, really simple—great sports to work in if you want an easy life.

But measuring that in MMA or a combat sport, or any sport where the aim of the event isn't to be in a particular part of the playing field or a particular part of the track, that gets really, really difficult and really, really complicated. And last time I was on the podcast, we talked about the previous paper we did in this area where we were just looking at the internal load, just looking at how the athlete's physiology responded to what they were doing.

Now for that we used—to measure internal loading event—at this, we used rating of perceived exertion, or specifically Foster's sessional rating of perceived exertion. At the end of the session you ask the athletes, how intense was the session from a rating of zero to 10, with 10 being absolutely flat out, hardest thing you've ever done, and zero basically being asleep.

Now there's quite a lot of arguments about how robust RPE is for measuring internal load, especially the physiological internal load, particularly if you've not trained the participant up in using RPE correctly, if they've been influenced by the training partners or the friends around them. And there's a bit of a debate as well as to how much RPE is influenced by the last thing you did in the session.

So for instance, most combat sports sessions, the last thing you do is a bit of sparring. And especially if you've got a fight coming up in MMA, the last thing you've done is probably some MMA sparring, which as we all know is pretty damn difficult, pretty intense. So there's a bit of a debate as to how strong a measure RPE is for overall training load. But there are things you can put in place to make sure it is as robust as possible.

But the main reason why we use RPE is because it's simple to understand, it's easily applicable, and it doesn't require any equipment. Now because of the grappling aspects of the sport, because of the actions involved in the sport, getting a heart rate monitor to stay on is difficult. It can do it, you can make it work, but generally speaking you're going to have part of the session where the heart rate monitor slips off a little bit.

And at the same time, there's—because they have so many changes in position, going from standing to grounded, having someone's weight bearing on top of you or being in a top position or asymmetric position—there's only so much heart rate can really tell us about the individual sections as well. So we chose RPE as a good internal load metric.

Now for external load, we've got a whole other kettle of fish there. Like for rugby, football again, we can measure how fast they've run, we can measure how many sprints they did, how many tackles they did, or how long they spent in certain positions of the pitch or the field. But in MMA, none of that matters. It doesn't matter how quickly you do something, it doesn't matter how long you spend in a certain part of the cage or in a training session, any part of the mat. So we need to have some sort of way of measuring the physical actions that they did.

Now for—well actually, this year now it's 2024—I've now been research active for 10 years. This is my 10th year as a researcher, which I'm quite happy about. I never thought I'd get to a 10-year mark. Obviously, like, I'm still a baby in research terms, but it's just like a nice little tick in the box for me.

But the first research work I did was looking if we can use accelerometry in MMA to try and measure the movements and actions that we do. Now the accelerometer that we tended to use is the Catapult range of accelerometers. Originally we were using the MinimaxX accelerometer, but they've updated their units and their kit over the last 15 years. Now the unit we've used on this particular paper is the Catapult Optimi S5.

Now Catapult do have a new unit out called the Vector unit, and I've not had a chance to play around with those yet. I need to have a look at those and see if it is just a direct comparison.

So essentially the accelerometers, they're about the size of a small mobile phone. If you had a—if you're old enough to have had a Nokia 3310 back in the day—which you can tell by the color of my beard I definitely am old enough to have had one of those—it's about the same size as that. And it just sits in a harness in between the athlete's shoulder blades, pretty much around the T4-T5 vertebrae.

Now all this unit does is it just measures the rate of acceleration in the three cardinal planes whilst the athlete's training. So at the start of each training session we got the athletes to put the accelerometers in the harness, and they just cracked on doing their normal session, doing whatever training they were going to be doing. Then at the end of the session we asked them to rate each section of the training in terms of RPE intensity, to try and find out if there was any relationship between the external load as measured by the accelerometer and their internal load as estimated by sessional rating of perceived exertion.

The aim being to get a better understanding of what are the athletes actually doing, has the session gone the way the coaches actually intended it to be. If they wanted it to be a high intensity, high load session, was it? If they wanted it to be a low intensity, low load session, was it? And then trying to find out, can we differentiate between the different types of training that MMA fighters and athletes do? And that's essentially what we're trying to do with this paper.

James de Lacey8:31

No, I love it. I love it. And I read through it just before this too, just to stay fresh. And I know you touched up on it too, so you're fresh on it as well. So I actually wrote down a bunch of things too.

But I actually want to just jump straight into the findings you had, and then I can just ask some follow-up questions from that and some of the random thoughts that I had just from reading it. So I mean, obviously just for the listeners as well, this is in this specific cohort of fighters at their specific gyms. So obviously it's based on their training schedule, these results. So that would just be a just maybe a limitation up front that people should know.

But the way they were training would be pretty typical of an MMA gym, would you say that?

Dr. Chris Kirk9:15

I would say it was pretty typical of an MMA gym with the caveat of being an MMA gym in the United Kingdom. This research was done across four different gyms, so each of these four different gyms have different coaches, different athletes training in them, and on the surface a different approach to what they want from MMA fighters as well. So one gym really pictures themselves as a striking gym where the head coach, he comes from a kickboxing background, very successful kickboxer and MMA fighter. That was his style.

Another gym, very much submission wrestling based, that kind of theme. Another gym, kind of a blend of styles, but they were very much focused on the wrestling side of it. They wanted to use striking to enter a takedown and then dominate on top.

But what we found was that regardless of what style the coaches were trying to achieve, they all kind of ended up doing the same stuff. They all pretty much had the same training duration. They all kind of had the same distribution of the training categories that we were looking at. And just to let people know, those categories were striking drills, wrestling drills, BJJ drills, and then striking sparring, wrestling sparring, BJJ sparring, and MMA sparring. So those were the broad categories that we classified them in.

But regardless of what the coach was actually aiming to do, what they wanted their style to be, they're all kind of doing the same amount of stuff, which kind of tells me that for the United Kingdom, at least, this does represent a standard MMA gym and a standard MMA training style and training practice. We didn't necessarily expect that at the start of the study, but that's kind of what came through.

I would, before starting this study, I was kind of thinking we're going to get a lot of different results from the different gyms because each coach has their own approach and their own thing that they want to do. So yeah, I'm happy that this does represent broadly MMA training in the UK. Obviously we can't say anything for any other country at the minute.

James de Lacey11:12

Do you want to just run through there, because obviously it's similar between the gyms, how the week was structured in this study in terms of training? So like Monday was mainly focused on these certain, I guess, those categories that you had there, and then the results might be easier for someone to interpret who's listening to this.

Dr. Chris Kirk11:40

Absolutely. In fact, the paper itself has two sections, so there's the actual normal paper with all the data and results in, but then there's a supplementary file as well that's available on the International Journal of Sports Physiology and Performance website. And that actually breaks down each day of the week in terms of how many minutes of each category they trained and what they were doing on each day.

And broadly speaking, each gym was aiming to have three high-intensity days and two low-intensity days, with those low-intensity days seemingly trying to be aimed on the Tuesday and the Thursday of each week. Now the reason why we can say they were broadly trying to get their low-intensity days on those two days of the week is those tended to be the days that they did their BJJ drills and their BJJ sparring.

Now the reason why we think they were trying to put low-intensity sessions on those days is through conversation with the coaches and with conversations with the athletes and fighters, and being from an MMA background, we've all got this idea that BJJ training is the easiest part of training MMA. We all see the striking is fairly high-intensity, the wrestling is really high-intensity, and the Jiu-Jitsu, we treat that as an easy session, don't we, in our minds.

So they all tended to put their BJJ sessions or the submission focus sessions Tuesdays and Thursdays, and you could tell from where the sessions were running that they were aiming for those to be low intensities. Now they all, every gym seemed to put most their sparring towards the end of the week on the Friday. So every gym would have high-intensity sparring sessions, MMA sparring sessions, and striking sessions on the Friday sessions, a little bit of sparring on the Wednesday and a little bit of sparring on the Thursday. Mondays and Tuesdays generally didn't seem to have much sparring included in those sessions.

Now we know from the previous study that we did, where we were measuring internal load for 30 weeks, that the MMA sparring and the wrestling sparring are perceived, are found to be the highest intensity as far as RPE. The MMA and wrestling sparring were both up towards seven and eight on the RPE scale, with the other sparring and the wrestling drills categories being around a five to six, being around a moderate, with only really the BJJ drills and striking drills being down in the low-intensity zone, round about a four. And that pattern again repeated across all four gyms. That's the kind of thing that we found from the data.

Now what we saw overall though, was that regardless of where they placed the low-intensity and high-intensity sessions, or what they were hoping to be low-intensity and high sessions, the overall load of each day was the same across the week. So even though they wanted the Tuesdays and Thursdays to be low load, low intensity, they ended up with the exact same load, or statistically the same load, on Monday, Tuesday, Wednesday, Thursday, Friday, Saturday. Everything was just a flat line across the week and between the two weeks.

Now this finding occurred in this paper and in our previous paper, we got the same result twice. Now we think the reason for that is what we were alluding to before, that we all seem to assume that submission grappling or doing grappling drills, BJJ drills, is really low intensity. So in our minds, and in the coach's minds, we don't mind doing an hour of just BJJ drills because, look, it's low intensity, how bad can it be?

But it's a high enough intensity that if you do it for long enough, it ends up producing the same load as a very short duration MMA sparring session or a short duration wrestling session. Now the whole aim of tracking training load is to make sure that you are getting an undulation throughout the week of high load and low load days, because it's those low load days that you end up getting your recovery.

Now I think, I can't remember who said it, but someone put it in one of their articles once asking, would you rather have a one kilogram stone dropped on your foot or a thousand one gram pebbles dropped on your foot? And I'm not sure the answer to the question. I think the one kilogram stone on your foot is going to be a lot of instant pain, it's going to hurt a lot when you first do it.

But if someone's dropping a thousand pebbles one by one onto your foot, how many hundreds do you have to have on your foot before, yeah, this is starting to hurt now, this is starting to cause me some pain? And which one is going to be worse? Which one are you going to recover from quicker? It's a tough one, isn't it?

So the idea of one session being short but intense, but another session being long and low intensity but really long, that's the argument we have for monitoring training load in this way. If we end up with the same load in both sessions, potentially we're going to get the same result in terms of athlete fatigue, in terms of athlete breakdown, and in terms of reduction in athlete's available energy, which requires greater recovery.

This particular study with the accelerometers, we measured them for two weeks, and both weeks essentially looked exactly the same in terms of training load. Every day looked exactly the same in terms of training load, both for internal load and for the external load. And I think it's due to us having pre, oh, before the study I definitely had these preconceptions, but I think the coaches do, the preconceptions as to which are the least intense and most intense sessions and how do we balance those out.

And I think at the moment the gyms are getting this a little bit wrong, not a lot, but just a little bit wrong at the moment.

James de Lacey17:30

I hope you're enjoying the chat so far. Before we get back to that, I just want to let you know that Sweet Science of Fighting is more than just a podcast. We have a full training app with strength conditioning programs for strikers, grapplers, and MMA athletes, so you don't have to think about what you're doing and you're getting access to the latest scientific methods to improve combat sports performance.

We have programs specifically for judo, for Jiu-Jitsu, for wrestling, MMA, boxing. Muay Thai is coming soon. All these things are going to be in the training app. We also have a private community where some of the coaches that have been on the podcast are in there to help you with any training questions and any performance questions you have, for example, Andrew Asher and Casper Darvit.

We also have some online courses within the training app. They cover strength conditioning, mental skills, and weight cutting. And finally, we now have Ryan Villalobos in the community, a second degree Jiu-Jitsu black belt who is there to break down any of your grappling matches that you want seen by a second eye. He's currently breaking down videos on a separate Sweet Science of Fighting YouTube channel, and he will break down your video within the community.

So if you have a match or a roll that you just recorded, you can upload that in there and Ryan will break that down for you. So what are you waiting for? Jump down the description, you can check out the Sweet Science of Fighting Underground, otherwise enjoy the podcast.

How would you change that then to have that undulation? Is it about doing the low intensity stuff just for less time on those lower days, or would you still be mixing in some high intensity work but still keeping the duration short? Is the duration the thing that matters the most in that instance?

Dr. Chris Kirk18:50

Potentially, yeah, potentially. Now, in terms of measuring internal load in this way using the RPE scale, we get the sessional rating of perceived exertion by taking the RPE and multiplying it by the duration of the session. Now that could have a big influence on how much the intensity matters and how much the duration matters.

Now there's a mathematical concept called mathematical coupling where if you're comparing two things but they've got a shared variable, then they're going to be very highly related. So if we're comparing training load as measured by RPE and we're measuring fatigue over time, both of those have a duration in them, so they're going to end up being kind of related. So we do have to take that into account, but that's one of the things that we looked at in the analyses in part of this paper.

So in this paper we tried to figure out which of these variables matter more for training: is it the intensity or is it the duration? Now we found that the internal load and external load both had very strong relations and correlations to each other. Now that could be because they both got duration involved.

But then we also compared the external intensity and internal intensity to each other, and we found that those two things weren't related. Now what do we mean by intensity? Intensity is a measurement expressed per unit of time. So when we measure RPE, that is the intensity of the session because that is our brains essentially have a way of thinking an average intensity across a session, and if we collect it correctly that gives us a good indication what the average intensity of the session was according to our body's feedback. All we do with training load is multiply that by how many minutes we were training.

Now for the accelerometry data, we get a metric called player load which is just the sum of all the accelerations in the three cardinal planes. Now if we divide that by the duration in minutes of the session, we get player load per minute. So you could have a session where the external load at the start is fairly low, a fairly low player load, and at the end it's a very high player load. Your player load per minute will be somewhere in the middle because that's the average intensity for the session.

Now we found that the sessional rate of perceived exertion, the internal intensity, and the external intensity, the player load per minute, they didn't have a shared relationship. So we know there's something different between these two measurements, and that's kind of what you would expect.

Now when we compared the internal intensity to duration, there was a very large correlation. When we compared the external intensity to duration, or sorry, the external load to duration, there wasn't that strong a correlation. So the external load itself isn't as dependent on the duration of training as much as the intensity, if that makes sense.

So this information kind of tells us that the internal load has a big effect of duration. If you reduce the duration of that training session, you're going to get less internal load from that session, but you might end up with the same external load.

Now there's quite a few reasons for that. So first of all, there's no reason why external load and internal load should match each other. So based on someone's fitness that day, how fatigued someone is, whether someone's feeling injured, whether they just can't be bothered training that day, they might have very different internal load responses to the same external load.

So if you do a session on Monday and the external load is 100 arbitrary units of player load, the next day might also be 100 arbitrary units of player load, but your RPE on the first day might be a nine and your RPE on the second day might be a five, just because you had a better night's sleep or just because you remembered to have some carbohydrate before you went in or just because on a Tuesday you're in the mood.

So essentially what I'm doing a very convoluted explanation here, but essentially the point I'm getting to is that I think it would be possible to base the training decisions around how much duration are you going to train each category based on the desired intensity you want from that category based on the external load. So if you want a low intensity BJJ session, then you can do it for a few minutes longer than you would a high intensity BJJ session.

So let's say you want a BJJ session of what's fairly high intensity for that training mode according to the data we've got. So let's say you want a BJJ session which is an RPE of six. Let's say that that will allow you to turn around and say, "Right, we're going to do a maximum of 30 minutes for the BJJ training tonight." However, if you want it to be a four, then, "Right, we've got 40 minutes of BJJ to play with."

Whereas I think what the current practice is, is the coach is thinking, "We've got a two-hour training block tonight. We'll do 45 minutes of BJJ drills, 10 minutes of rolling, and then we'll get into the striking stuff," and they seem to approach every session like that.

So we do have to consider both intensity and the duration, but I think the key variable that we would alter in our training planning will be the durations of the individual segments of training. That would be the easiest way of doing it, and I think because of the way training load works, it will be the most effective.

James de Lacey24:44

Gotcha. Yeah, that's definitely something I found in team sports as well, is playing with the duration as the easiest way to manipulate the training.

We have Andrew Usher in the chat here. He's asking a couple of questions, so I'll start with this first one. It's actually one I had down as well that I was going to get to, but he's asking about what about the subjective nature of RPE? And obviously you've talked about some of that there too.

But I was going to follow that up with, you know, what if a fighter has a strong background as a striker or a grappler, so his perceived exertion of doing Jiu-Jitsu or boxing, et cetera, is much lower than someone else? How does that affect the overall data? It's a very general question, but how does that affect the overall data and maybe how someone would plan their training? Would you have to just then rely more on external load?

Dr. Chris Kirk25:31

Not necessarily. And hi Andy, by the way. Good to hear from you. Met him.

I'll do with the first topic of RPE being a subjective measure. I don't actually classify it as a subjective measure, but I don't classify it as an objective measure either. I think it falls somewhere in between the two. I kind of call it a quasi-subjective measure.

So yeah, on the surface we are asking the athlete to rate how intense they felt the session was, but there's quite a lot of research going on at the minute, particularly from James Steele down at Solent University in Southampton, is trying to get a better understanding of what are we actually measuring when we measure RPE.

So there's two—I might get this a little bit mixed up, but I'm sure James Steele will let me know if I do get this wrong—there's two conflicting theories as to what RPE is actually telling us.

So the first theory is that when you exercise, when you train, you're having changes in homeostasis in the muscle, in the body, and those changes, whether they're chemical changes, whether they're mechanical strain changes, whether the temperature changes, those get fed back to the brain and the brain interprets that as an RPE score.

Now some recent work by James is kind of showing that that's probably not true, that it's probably not dependent on what the body is doing physiologically. It looks like there might be a small element of that, but only a very, very small one. And the way they determine that is by quite often using pharmacological methods to essentially cut off the feedback going back to the brain—not by literally cutting it off, but just by interrupting it using drugs.

Now the other theory is that we all have already, through our own experience, an idea of how difficult something's going to be, and this is called the corollary discharge theory. So essentially, before we start doing something, we've got a subconscious idea of how difficult it's going to be. And if you've been using RPE, then that will come up as an RPE score.

Subconsciously, you're expecting it to be, let's say, a five on the RPE score, and then you start doing it and your interpretation of how difficult it is then gets fed back to your brain and compared to that initial subconscious idea. And if it comes back that it is a five, then your RPE ends up being five, the RPE that you tell to the coach at the end.

If it ends up being a bit more difficult, then your RPE can jump up quite rapidly. So if you go in thinking it's a five and you actually find yourself struggling to complete the session, your RPE might go up to a seven or eight. If you find it's much easier, it might drop down to a two or a three. And that's—I might be getting a couple of things wrong on that. I'm sure James will let me know. He's good at picking people up on this kind of stuff when—

We get RPE wrong. So we got the corollary discharge measure there, but both of them are based on the actual physical intensity that you're going through and what the body's actually doing whilst you're training. So on the question you asked, James, about if someone comes from a striking background, are they going to find the striking easier? Well, yeah, they will do. But you get that same effect if we're measuring heart rate.

So because someone is from a striking background, they're going to find the striking drills a lot easier anyway because of exercise economy, because they're used to doing those skills, because they've got lower cognitive load when they're doing those skills. So everything's going to be reduced anyway. So RPE should reflect those changes anyway.

Now, in order to try and move it a little bit further away from being a subjective measure towards an objective measure, that very much comes into how you actually train the athletes to use the scale in the first place. So quite often what we tend to do, especially when we're teaching this to students—I've had a lab session this week with some of our undergrads—and because of time constraints, we're saying, right, we're going to collect RPE.

This is an RPE scale. What you do is you show them the sheet and get them to point at the number they're feeling at that point. That's the worst way of collecting RPE. That's where you get all your problems with RPE because it's not anchored or linked to anything that they experience or that they understand.

So essentially what we need to do in order to make sure that RPE is as close to being objective as possible—and we're never going to get it fully objective, it's always going to be halfway in between—is essentially spend a couple of weeks going to the training session, asking them to rate the training session in terms of intensity.

And the first time they do it, just let them record it, walk away. The next training session, get them to rate it again, and then asking them, okay, so you've done the same session twice. Yesterday you rated it as an eight. Today you rated it as a four. Why were those two sessions different?

And then you start getting the conversations to, well, in this one I was going through these kind of actions. I was training with this person. I was feeling this kind of pressure. Whereas today I weren't feeling those things. And then you start asking questions of, okay, so if that one was an eight, how does that compare to the hardest wrestling session you've ever done?

Like the time the Polish Olympic team were here and you wrestled against those guys. How does that compare to that? Oh, that was actually a lot easier than that session. Okay, so why is this session an eight then? I know when you put it that way, it's probably closer to a six.

Okay, so what I want you to do, and the next time we do this kind of session, I want you to anchor the most difficult session of 10 being the time against the Polish Olympic squad. Okay, got you. Brilliant. Now this session, we rated it as a four. What was the easiest wrestling session you've ever done? It was this one where we were just going through very low intensity, just dropping onto a single leg or not completing it.

Okay, so where would you rate that? Oh, I'd rate that as a one or a two. Okay, so this session today, would you mean that up or down based on that? No, I'd probably keep it the same way.

And you go through this process, this conversation, at least for two weeks of training sessions to get them to anchor the statements to what they are actually experiencing that day and how it compares to other sessions as well. Now, the problem with that, of course, is it's a massive pain in the backside. It takes a long time and you have to be working with athletes and participants who are willing to engage in that process and are willing to think back to their previous experiences and relate it to the scale.

So for everyone who's ever worked with athletes has a story about a player who, every single RPE, no matter the session, yet was a five. That, yet was a five. That, yet was a five. We've all worked with people like that. If that's the way the athlete is going to approach it, their data is no good. The RPE scale is no good for them and you're not going to be able to use it in research. You're not really going to be able to use that data to program the training load.

So that obviously is a big downside to using this method. And if you've got something like that, it's 100% subjective, which means it's kind of useless for you. So yeah, great question from Andy about the subjectiveness and great question from yourself, James, about what do we do if there is someone more skilled or from a different background.

If they're from a different background, those are the fluctuations we expect to see anyway. In terms of how that affects research, same answer to everything: you just got to get a sample size that's big enough so it blends in and becomes part of your data rather than skewing it.

James de Lacey33:15

Before I get into more of the practical stuff too, Andrew's got one more question here for you and it's around the player load algorithm with the Catapult GPS. So he's saying, was the tech changed for the difference in movement planes compared to other sports, or was it manually calculated from raw data?

Dr. Chris Kirk33:15

Great question again, Andy. No, so the tech wasn't changed from ambulatory movement scores and we didn't calculate the output from the raw data either. I understand where Andy's coming from there because there's been a couple of papers now where they found that the way the player load algorithm works and is designed, it's been designed very much for upright running and they kind of only really tested it to be truly representative of upright running.

Now, this is a bit weird. This is a bit weird for Catapult because it was designed originally with Aussie Rules Football in mind. And as you know, in Aussie Rules Football there's not a lot of straight line running and they don't get to spend a lot of time stood upright whilst running. It's pretty quick before they get hit. There's been a couple of studies where they've used a Vicon system to measure changes in body angle while you're running, using player load to put correction metrics onto those data to essentially give a better, a more accurate understanding of what they're doing.

In this situation, for these particular studies, we didn't have the time or resources to do that kind of work. And also the number of different movements we'd have to do that for just, it doesn't make it impossible, but it certainly makes it very, very difficult, particularly for someone like myself who's, when it comes to biomechanics, that's like witchcraft to me when I'm looking at biomechanical work. I'm not built for that stuff. So that work definitely needs doing.

Now, in terms of calculating the player load yourself from the raw data, technically that should be manageable from the raw data output that you get on the CSV sheet. But there's a paper by Brett—B-R-E-T-T, B-D-T—that they came out a couple years ago, and they compared the algorithm, the equation that Catapult provide in their manual, to the other reportings of the specific algorithm that have been reported in a few papers. And there's quite a lot of disparity between the way these different papers report the algorithm.

Some of them put the brackets in a different place, which obviously changes the equation. Some of them there's a squaring factor to the algorithm. Some of them put that inside the brackets or outside the brackets. There's a dividing line. Some of them put the brackets around the dividing line or just on top of the dividing line. So there's quite a lot of, basically everyone reports a different equation.

Now, this same paper also used the player load equation on the raw data and found that the player load data, the player load equation applied independently to the raw data, gave you different numbers to the one that the Catapult unit spits out. Now, that does bring a really good question: do they have other correction factors built into the Catapult unit? Is the number coming out from the Catapult unit, is that determined based on the software or whether it's been updated, or is it just malfunctions within the actual unit? We don't know. The questions that we don't know how to answer that question at the moment.

But because of all these things, we felt the safest way to go in the time and resources that we had for these particular studies was just to use the player load number that came out of the unit with the caveats built in that there might be some errors in there. But we're not actually, at this point, we're comparing it to any other output.

We're not comparing it to a different accelerometer unit. We're not comparing it to different sports. So for us, those limitations are manageable for the moment. If we do want to do comparisons in the future, we are going to have to do what Andy says and do some extra work around it.

James de Lacey37:07

It sounds like a lot of extra work too, so I don't blame you.

But to get this practical as well, I'd love for you to run through the different—so you had the categories: jiu-jitsu drills, striking drills, sparring, etc. Run through from lowest intensity to highest intensity with that, because I know I'd love to hear your take on it. Because within your paper you have, for example, jiu-jitsu drills, very high internal load but lower external load, and then vice versa for striking drills. So I'm wondering how you would, I guess, on a—

On a scale, rate them from low to high if someone was going to potentially create their own training program.

Dr. Chris Kirk38:00

So in terms of the low intensity work, it kind of depends on whether you want to base low intensity on the internal intensity or the external intensity. For the striking drills, for instance, we found that they had a relatively low internal load but a relatively high external load based on just the playload. And that external intensity based on playload per minute was also relatively high compared to the other factors.

Now I would recommend basing it on internal load, the internal intensity that you want, primarily mainly because it's the internal intensity and the internal load that causes the physiological adaptations that you want. The external load and external intensity, the only reason you need to understand that is so that you can get to the internal load and internal intensity that you want. This whole framework is just to allow us to make up for that discrepancy between what we do and how the body responds.

So even though we have fairly high playload for the striking drills but fairly low internal load for the striking drills, I would focus on the internal response first and foremost.

So if we're going to do that, then the lowest intensity or lowest load work in terms of the drills actually came through as the striking sparring, followed by the wrestling sparring. But that was largely due to the durations that they used it for.

So if we look at the previous paper we did in 2021 where we had the RPE, we had a figure showing the RPE for each category as you go up. And essentially it starts off with striking drills and BJJ drills being the lowest intensity, then striking sparring and wrestling drills being the next highest intensity with BJJ sparring in with those two, and then the highest intensity was wrestling sparring and MMA sparring. So looking at those three broad categories, to some extent it's kind of as expected, apart from striking sparring and wrestling drills being equal in intensity.

So if you want a low intensity day, BJJ drills and striking drills for a relatively moderate to short duration, that's where you want to go. If you want high intensity day, wrestling sparring, MMA sparring for short durations. If you want moderate intensity, it's everything else. So whether it's your BJJ sparring, your striking sparring, or your wrestling drills, that's where you're going to get your moderate intensity days from.

So I think that kind of works out well for MMA training in general, because I think if you want to be a well-rounded MMA fighter, those three moderate things in the middle, that's kind of the bulk of the things you want to be good at. Striking drills and BJJ drills on their own, they're going to help you, but you need to have that wrestling and striking sparring on top.

The MMA sparring, you got to put it all together at some point, but you don't want such a high load on your athletes all the time. And just the physical strain of sparring, you don't want to do too much of that anyway, alongside the excess brain trauma that you don't need as much of either.

James de Lacey41:10

Nice. That's a good way to put it. And hopefully the ones listening can do that, so want to implement or maybe just even track their own training load. How would you recommend they do that?

Dr. Chris Kirk41:10

Excellent question. Now there's two ways I think that we can go about doing this. The best way to go about doing it is to look at the methods using this paper and replicate that with your own athletes. So collect, set them up and train them up properly on the RPE scale, monitor that in every single session, ideally for each training category that you have.

Also attach them with an accelerometer, measure the playload in each session in each category, and then the relationships in this paper, work those out for your athletes independently. And then from there, after two weeks, three weeks, depending on how many athletes you do it with, you should be able to develop a good understanding of how much of each category do they need to train in terms of duration to get the internal intensity response and internal load response that you want.

Downsides of that: it takes a long time to do it, it takes a lot of work on your half, and it requires the athlete to really be engaged with it. Equally, these accelerometers are damned expensive. This is why they're only ever really used for research work or by Premier League football clubs or rugby clubs, because they are very expensive to get.

So another option, and one that we've actually built into the paper as well, you can use these data in our paper along with the regression equations in our paper to estimate how much time you would need to spend on each training category to get the training load you want for each day.

So if you are a coach who wants a low intensity day on the Tuesday and Thursday with high intensity days on Monday, Wednesday, Friday, well you can split up the week in terms of your target training load and then work out what external load you would need in each category to meet that internal load need, and then what duration of training gets you to that external load. So the equations that we provided, the data we provided along with the equations in our paper allows you to do that.

Now that is only a starting point, because obviously these are not your athletes. These are different people, potentially training at different levels. But at least it gives you a starting point that you can fine-tune towards your needs. And in fact, there was a paper that came out just before Christmas from David Bosa, I think his name is, and the paper was essentially about, we got all these training load metrics, all this way of monitoring training, but the whole point is to allow the coach to fine-tune it to what they actually want to do.

So if you don't have the equipment or time available to measure all this yourself, then you can potentially use the equations in this paper to start to give you a starting point, and then over a few weeks of training and feedback from your athletes, fine-tune it to get it to exactly where you want it to be.

James de Lacey44:04

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But my personal favorite, this is my personal favorite, far we have this in black and white and it is the Taniwha, protector, guardian version of the Sweet Science of Fighting with the logo on the back. This was designed by a Maori designer back in New Zealand, so a bit of my heritage on this jersey. It represents the acknowledgement of battle and war.

It also represents strength and stability and also has the New Zealand silver fern. But even if you're not a Kiwi, cop this. This is an awesome design. It is a custom-made design, you will not find it anywhere else. So check that. That'll also be down in the description with a discount code. But back to the podcast.

For most people that probably want to have access to the external load stuff, so they'll be doing internal load tracking, so RPE multiplied by session duration. What would be like a typical training arbitrary unit week, like total training load, say, for MMA? And there may be a typical cool day, what that would look like. So if someone is going to account, I'm going to start tracking my own training load, at least I have an idea of kind of what would be typical.

Dr. Chris Kirk45:54

Yeah, that's again, that's a really, really good question. Now in terms of what's typical and what's ideal, that's a whole another debate there. We found a typical week in terms of arbitrary units from the sRPE was looking at anything between 4 to 5,000 in AU thereabouts. Whether that's good or not, we don't know.

It's a long way below what you would expect to see from a track and field athlete, for instance. It's a long way below what you'd expect to see from even an Olympic weightlifter. It's about the same as you'd expect to see from an association football player, a soccer player. But obviously these are all very different sports. We don't know really if that's good or bad.

There's a paper that came out a couple years ago, I'm sorry I can't remember the lead author's name, but he's Australian. He was working at the AIS CPI at the time, and he did some research with heart rate variability. And I think his suggestions, based on these data, were a high load day in terms of sRPE would be about 800 AU and a low load day would be about 500 AU. Which if you're looking at having two low intensity and three high intensity days per week, that kind of gets you around about 4,500 AU. So it could be around about there.

But again, we have no idea what the effects of any of these loading parameters are. We've no idea if that pattern would actually lead to optimum, oh sorry, minimum fatigue with optimum results. All of this work still needs to be done. And I keep saying every podcast I go on, we're barely at the starting line. We're just about passing

James de Lacey47:52

Go and collecting 200 pounds. We've got so much to learn about this sport.

Yeah, I actually have a follow-up question to the study there. Something that I saw in there that piqued my interest, because obviously the application is well used within other team sports like rugby and soccer, is the idea of game speed and manipulating game speed through that external data. And you had in there PlayerLoad per minute. So obviously PlayerLoad per minute, you can kind of look at as like a game speed or density metric for people listening.

And it would be interesting to know, like, maybe in the future if there would be a way to potentially look at designing training sessions around that PlayerLoad per minute to exceed maybe a certain threshold that is seen within a competition. Obviously, I don't think we have any data yet of actual competitive matches in terms of PlayerLoad. That might be something in the future. But if there is, or if there was, say for example 4.5 PlayerLoad per minute or whatever it is was an average—I think in a lot of those training sessions—but let's just say, I don't know, within a peak round there was, I don't know, 6 PlayerLoad per minute.

Maybe we could try and design training drills that exceed that to almost look at games. I don't know if that's something you've thought about, any random thoughts on that topic.

Dr. Chris Kirk48:46

I think that'd be a really good application of this data because at the end of the day with in our sparring sessions we're trying to replicate an actual fight, aren't we? It would make sense for us to be able to see, well, in this sparring bout, in these three rounds we've done today, are our fighters actually working at the pace to replicate competition? That would be, that's exactly where I want to go with it.

Now, we did do PlayerLoad from some sparring bouts in 2015, but that was only from six participants in three rounds of five. And I think it came out about—I think PlayerLoad came out about 14 AU per minute, I think, off the top of my head.

Now, we're currently working on a paper. We're currently in the writing stage of it where we've done 10 participants going through 3x5 sparring rounds. And the aim of this study actually is actually to compare PlayerLoad to their aerobic metric collected in the lab.

Now, the PlayerLoad per minute in these matches has come out, I think, around 11 AU per minute. So that suggests to me that an average MMA sparring match, at least, is about 11 to 14, 11 to 15 AU. So that could be a potential threshold for people to target for working in the actual sparring matches. But we don't have it from competition, from official competition anyway, because in MMA you're not allowed to wear anything on your upper body apart from obviously women are allowed to wear the sports bras.

A potential way around that could be in IMMAF competition. Now, in IMMAF competitions every fighter wears a rash guard, so if some work could be done with one of the IMMAF competitions where one of the teams or some of the fighters are allowed to wear a Catapult unit under the rash guard, or if it's built into the rash guard, that'd be an amazing opportunity to collect these data in an actual live competition. Because we know it, as in every sport, match simulation always has been different to real life competition, where you can never fully replicate it.

James de Lacey51:04

That would be interesting. I actually completely forgot about, yeah, you can't wear anything on the body, but the IMMAF, that could definitely be something interesting. You probably would need a rash guard that has the thing on it. Do you have any pushback from fighters that don't want to wear the vest?

Dr. Chris Kirk51:04

No, to be honest, I always let them try it on first and just go through a few positions and movements first. And to be honest, because of the way, because it was designed for use in Aussie rules and in rugby, it is designed to sit just into that gap in between shoulder blades. So the only time really that people notice it, it tends to be the jiu-jitsu guys who I put it on, because in jiu-jitsu you get sat on your shoulder blades quite a lot. It doesn't tend to happen in MMA.

So to be honest, most of the time they forget they're wearing it. And they say the only time they remember they're wearing it is if they're pushed up against the cage and the unit just falls in between the gaps in the cage, or if they're in a scramble and their thumb just happens to slip behind the harness at some point. But other than that, the feedback is that they forget they're wearing it as soon as they start the sparring or start the training. So it is, it's definitely usable in the real world.

James de Lacey52:13

Perfect. Andrew's commented here saying that they have a discussion about putting units into rash guards and they have a full of prototypes at the moment. So I think you guys need to link up and, Andrew, you need to collab, Sweet Science of Fighting, we need to sell those rash guards for sure. So that would be a very interesting, very interesting thing for future research too. But I think that covers everything I wanted to ask you. Anything we wanted to add on about that research just to finish off?

Dr. Chris Kirk52:40

Well, at the moment, based on, one thing I am working on, not research-wise but application-wise, is I am at the moment trying to figure out the best way of using these regression equations that would come up and using these data that would come up to actually build a training framework that a coach will be able to plug their own requirements into and get the durations, the suggested durations out of.

I've got a couple of coaches who, once I've got a working prototype set up, that they'll trial it in their clubs. So if any MMA coaches or athletes are listening who want, who are interested in having a look at this prototype and testing it with their fighters, please give me a shout. I'll be happy to, I'll be very happy to share it with you and get that word rolling out.

James de Lacey53:33

Awesome. I'm going to hit you up about it just to take a little look and see what's going on. But where can people find you and keep up with what you're doing, Chris? I know you're pretty active on, I think, Facebook and a little bit on Twitter.

Dr. Chris Kirk53:33

So if you want to contact me by email, then the best email to reach me on would be c.kirk, which is k-i-r-k, @shu.ac.uk. I'm on Twitter. I always get this wrong, Chris_Kirk_RSP, you can find me. You can find all my papers on ResearchGate, which is researchgate.net, I believe. I'm just Christopher Kirk on there. And if you don't have access to ResearchGate, just drop me an email. I'll happily share all my papers with you, whether I'm really allowed to or not.

I am on Instagram, but I don't use it, so you can follow me on there if you want. You won't see anything. And other than that, just all the usual places, LinkedIn, Facebook, all of that.

James de Lacey54:28

Perfect. Now, thanks for coming on, Chris, and sharing, I guess, sharing your take on the research paper that you just recently published. And hearing it straight from the researcher's mouth is always good. And it's nice to kind of expand on some of the findings there for the listeners to kind of get a practical take on it all. So appreciate you coming on. We'll for sure have you on again as you keep publishing and having new findings.

Dr. Chris Kirk54:50

Excellent. Thanks for having me on, James. And, yeah, thanks for inviting me to talk to the combat sports community. We're too spread out. We need to do more of this.

James de Lacey54:50

Perfect. For sure. I'm bringing back guests for all the new research. I'm cycling through everyone again and trying to get all the new research out, because obviously the research doesn't reach a lot of the, I guess, the average combat sports coach, etc. So it's good to be able to do some of this and get it out there so it's more well known.

Dr. Chris Kirk55:13

Yep, 100%. The more communication we can get done with the coaches and the athletes, the better it'll all be in the end.

James de Lacey55:13

Exactly. Perfect, Chris, for coming on. Thank you very much. Have a good one.