Dr. Chris Kirk On How Body Type Affects MMA Performance & The Perfect MMA Training Week (SSOF Ep. 23)

Dr. Chris Kirk1:25

And that's even been linked to swimming performance as well, strangely. I don't know if that's just a bit of an artifact of certain limb lengths are good for swimming or if there is actually something to that.

Now, the big one in combat sports is the whole thing of height and reach. So before a boxing match or before an MMA fight, we always have the two photos of the fighters put up with their age, height, weight, and reach. And this kind of comes from, well, traditionally in boxing, because the thought process is if you've got longer arms or a longer wingspan, you'll be able to strike your opponent more often and they won't be able to come in and strike you.

Now, when did I first start looking at this? I think it might have been around 2014, 2015, when I read a, I can't remember the name of the book, but I know the name of the author's gone. I'll drop you a message to put in the notes. But essentially there was a chapter in this book where it was looking at the statistics from UFC matches and looking at the height and wingspan of MMA fighters.

And they found that the champions in each division at that point had longer wingspans and were slightly taller than the average in that weight class. So I think the champions at the time were Jon Jones, who's obviously known for having a very long wingspan, Anthony Pettis was lightweight champion, very long wingspan in comparison to also the lightweights. And the conclusion of this chapter was essentially, well, having a longer reach makes you a better MMA fighter, makes you more likely to win.

So I decided to, well, look at that, does it actually give a better chance of winning or not? So in order to do this first study, I was up every Saturday night watching the fights anyway. At the start of each fight, I just take a quick screenshot on my phone of the height and reach data and collect that over the course of a year. So by the end of that year, I had 400 individual height and reach measurements.

And we'll come on to, we'll come on to the caveats of these measurements in a moment, because there are a few woolly issues around these measurements. But essentially we found, I found, that there was no difference in the height and reach on average between the winners and losers of any MMA fight. And there was no difference in the heights and reach between champions and non-champions or people who fought for a title and those who hadn't fought for a title.

I found that there was no difference in if you took the top 100 fighters in each division and split them into three levels, upper, middle, and lower, there's no difference in the height and reach between those levels as well. So this led me to the conclusion that the idea of height and reach is greatly overstated in MMA.

Now, it seems there is an effect in boxing. A study by, I think it was, who I believe is an Eastern European researcher, they found that a longer reach does mean you're more likely to win in boxing. So what's the big difference between boxing and MMA? Well, it's the grappling.

As soon as you get close, as soon as you grapple someone, to get hold of them, the length of their arms is virtually irrelevant. And once you get onto the ground, again, the length of your arms and length of your legs in comparison to body, virtually irrelevant. So I think the idea of height and reach being important in MMA specifically is greatly overstated.

Now, could that be because we have such wide weight division categories in MMA and people do so much weight cutting that when you actually get into your division there's not that much difference in height and reach between the opponents anyway?

Now, the caveats around that is how has height and reach been measured in these athletes? The answer is we don't know. And there's, you see a couple of things online where people, I think it was, in fact it was Daniel Cormier, someone had the height and reach data of three Daniel Cormier fights, and his height changed by about four or five inches between those three fights.

James de Lacey6:20

Yeah, it's the same when you see stats of rugby players on the TV. I know they often over-inflate the weight and the height just on the stats, so I'm sure they do the same on from the UFC or whatever other organizations are printing the stats.

Dr. Chris Kirk6:20

Well, and I think that happens, well, it definitely does happen in basketball as well, because in rugby, basketball, if you're trying to get picked up by a pro club, you have much more chance of, in rugby, being picked up if you're 6'5" and 110 kilograms than if you're 6'2" and 90 kilograms. Same thing in basketball.

I grew up playing basketball, and at a basketball camp I met Steve Nash once. And at the time he was listed as, he was listed as 6'3". I'm 6'4", and he was around there on me. Steve, definitely not 6'3". But really, being a young Canadian lad, increasing your height a little bit gets you a bit more noticed by the coach. There might be a similar thing happening in combat sports and MMA, maybe.

James de Lacey7:18

Yeah, for sure. It's there. I guess, so why there's not much difference, maybe in terms of outcome of the fight based on your anthropometry, is there, I don't know if you cover, maybe like certain styles that may be better suited for different, I guess, limb length and body shape and things like that?

Dr. Chris Kirk7:46

Yeah, this is actually something that I do want to look at because I did do another paper in, I think I did it in 2018, but by the time it ended up in publication it was 2020. This was looking at the in-bout statistics of number of strikes thrown, number of distance strikes, number of clinch strikes, number of takedowns, so and so forth, and tried to find if there was any relation to any of these techniques and limb length, stature, the, what's called, the commonly called the AP ratio, which is the scale between a person's height and their wingspan.

And we found that really there's very few strong relationships between these things. But we did find that in some divisions, or the heavier divisions, heavyweight in particular, the longer your reach was, the more chance you have of scoring a knockdown. Whereas at featherweight, the longer you're, sorry, the greater height you were, I think it gave you a better chance of actually scoring a takedown.

Now, we can't draw many conclusions from that at the moment because we do need to have a better understanding of, well, what is a fight style? How do we determine whether someone's predominantly striking, predominantly grappling, or a mixture of them? 15 years ago, that would have been fairly straightforward. A lot of people who were wrestlers who learned to box or kickbox who to stuff a takedown.

In the current era, you don't really get many people like that. Everyone seems to be a true mixed martial artist. So in order for us to do that kind of study, we need to figure out a reliable way of measuring

Someone's fight style. Now, Dr. Oliver Barley from Australia, he – one of him and one of his students – actually put out a paper where they asked the individual fighters to rate their own fight style on a 100-point scale. So 100% striker at one end, 100% grappler at the other end, and they asked them to literally write whereabouts on this scale do you think you are. They didn't necessarily validate it, but they showed that it could potentially be doable, it could be possible.

So I think that is something that does need looking at, because it might be a case of we have so many people focusing on strikes, just into a grapple, that skews the data. So if you went into a cage and thought, "My entire remit is just to stay on the feet, just stay striking, just stay at distance," then yeah, limb length might well make a difference there.

But if you're going in the fight thinking, "Okay, I'm going to set up a few jabs to get in close, get the clinch, get the takedown," then maybe – you might have a long limb length, and your long limb length on the jabs might be helping you gauge the distance to get the takedown, but it's not necessarily affecting any of the other statistics.

And this, I think, is a really good reflection of just how complex MMA is as a sport. So many different things going on and so many different determinants going on that really pinning down where that influence is or isn't, I think is going to be really tricky. But that is something I want to look at some point in the next couple of years.

James de Lacey11:03

Yeah, that'd be very, very interesting as well. And I wonder if – I don't want you to be like, "Yeah, you should guys, you should be in this weight class based on your height or whatever," but maybe if someone's struggling to figure out kind of what weight class they should be and if they should cut down or kind of bulk up to move up, is there maybe a way for someone to determine, "Hey, I'm this tall, I know generally that this weight class might be a better fit for my body type?"

Dr. Chris Kirk11:23

I think to a certain extent, coaches are already doing that. And I think to a certain extent, coaches tend to do that more based on height and actually how thick the person looks in terms of muscle.

So I think at the moment, if you're going into an MMA gym wanting to fight and you're 6'2", 6'3", I think the coaches are already looking at you thinking middleweight, because if you look at most of the middleweights at the elite levels, they're about 6'2", 6'3". If you're going in at 6'2", 6'3" but you're pretty much – your build, lots of muscle, typical rugby player body – then the coach is probably thinking, "We're not going to be able to cut that person down.

Let's make them even stronger and make them effective at heavyweight." So I think coaches are already doing that based on general body shapes and sizes anyway.

Whether someone could use it to think, "Well, what's going to be a better weight class for me? How much weight should I be cutting?" From a safety standpoint, I think that much more needs to be done from what is the person's energy availability, what is the resting metabolic rate, how much fat are they actually carrying at that point. I think that's going to be far more important and far more usable to determine someone's weight class rather than just how long do their bones happen to be.

James de Lacey12:52

No, fair enough. And you mentioned obviously you took pictures of all the height and reach of all those fights. Does that mean you were staying up to like 3:00 a.m. to watch these fights, because you're in the UK, right? Isn't the time zone not favorable?

Dr. Chris Kirk12:52

Yeah, unfortunately. My entire life I've been watching sports that don't happen in the country where I live. So like I mentioned, I grew up playing basketball, so the NBA finals every year I was staying up till 5:00 in the morning to watch Michael Jordan win another ring. And now, yeah, every Saturday – unfortunately – the main card actually starts around 3:00 a.m. here, finishes around about 6:00 a.m.

These days I'm only staying up for the big cards, so like the big title fights, and then everything else I'll watch the morning after. But yeah, that was a good 10-year period where every Saturday night I'd be up till 6:00 a.m. watching the fights and yeah, getting up bleary-eyed at 12:00 the following day wondering why I did that. But that's what happens when you're obsessed with something though, doesn't it?

James de Lacey13:46

Yeah, it's all information for the listeners on this podcast, so all comes to fruition in the end. But I wanted to go into one of your other papers as well. I guess we could call it periodization for the MMA fighter maybe. Essentially, so do you want to maybe dive into maybe some of your findings in that paper regarding, I guess, training structure for MMA fighters, maybe things you found, tips maybe that you can give to fighters looking to schedule their own training weeks, months, however it is? And I guess anything else on that topic.

Dr. Chris Kirk14:12

Yeah. So I suppose this really brings me on to talking about the PhD that I recently finished at Liverpool John Moores University under Professor James Morton. The aim of my entire thesis really was to try and quantify what MMA fighters are doing in their training. Because, I mentioned at the start of the podcast that I started research in 2012, that's when I became research active, and then at that point I was just about starting my Masters in Research at the University of Central Lancashire.

And I went to the person who ended up being my supervisor, Dr. Howard Hurst, with an idea about looking at whether breathing restriction methods are useful for MMA during their training, because I'd seen a video of Wanderlei Silva with headgear on, his nose all taped down, and then breathing through a straw while completing a circuit. Just absolute madness. I looked at it and thought, "Well, maybe it does work. Maybe he's getting something from it."

So I went to Howard and said, "Is this something we could research? Could we do a study on this?" And he said, "Right, first we need to do – what information do we already know about MMA?" And he sent me away to find every paper that I could on MMA, and I could find five.

James de Lacey15:42

Studies? Well, even now there's only maybe – well, maybe a few dozen maybe. There's not too many. Or did you get more deep dive there?

Dr. Chris Kirk15:42

There's more now, but there's still not that many. I ended up having a very similar conversation with James when I started my PhD, and then we found 120 in total. So there has been a bit of a step up. But if you look at how many papers that are released on soccer, on association football, it's about 120 a year, not 120 in the entire existence of the sport.

But because it was only five papers in 2012, we had to come back to square one and find out, "Well, what is the sport? What are they doing? How can we measure the external load and the internal load?" So my Masters was essentially figuring out the reliability of accelerometry for measuring the external load and then measuring individual movements.

Now, the question I had after that was, "Well, what does an actual training session look like? How can we measure what the fighters are doing in a regular training session and quantify what they do on a day-to-day basis?" And it took me a bit of time. I was applying to a few different PhD scholarships, being unsuccessful at each stage because of just how competitive these things are. And eventually I was able to get a place at Liverpool John Moores. But I still had that question: what are they actually doing in their training sessions?

So that became the first study of my PhD, actually observing MMA fighters doing their regular training with no intervention for eight weeks. Eight weeks was just a solid block of time where we could get people consistently in every session. And we did that research at four different clubs, starting off with 25 participants. A few people got injured, a few people dropped out of the study, which happens in these kind of things, and we ended up being able to track 14 fighters for eight weeks.

Collecting their sessional rating of perceived exertion to get their internal load, we had two weeks at each club where they wore Catapult accelerometers to get their external load, and we measured their fatigue through fatigue questionnaires and reaction time. And what we found over the eight weeks – I personally was expecting to see some sort of undulation over the course of eight weeks, so there'd be some days where there'd be really intense, other days where there wouldn't be that intense, some weeks where there'd be really intense, other weeks where there weren't as intense.

But instead what we found across eight weeks was nothing changed. There was no change in the training load, there was no change in the intensity, there was no change in volume, and as such, there was no change in their fatigue levels. Now, we got lucky with this study as well for one part of it. It just so happened that of these 14 participants, seven had fights during the eight-week period, so half the group. Just dumb luck, we ended up with a nice experimental comparison between the seven people who fought and the seven people who didn't.

Even comparing these two groups, there was no difference in their training load, there was no difference in the intensity, no difference in the volume, up until the week of the fight where the guys who were fighting just didn't train. That's the weight cut week. So there was no two-week taper, there was no change in how they were training right up until the week of the fight.

There was no what we would recognize as periodization, there was no undulation, there was nothing that you would recognize from a physiological standpoint of this person's getting ready for athletic competition. Which part of me was surprised at that and part of me wasn't, because I've been around MMA gyms and combat sport gyms for over a decade. I've already seen how people train, but I was still expecting some kind of change to occur being the lead up to competition.

I actually thought it would go the other way. I thought that intensity would just increase, increase, increase and then drop off. The fact it just stays the same was what was surprising for me.

James de Lacey19:34

Okay, that's interesting. So I guess the questions from here would be then how would you, I guess how would you then like to see a week structure in terms of that undulation regarding the intensity, and then what the accelerometer, do I know in the paper you mentioned obviously it covers, I think it was it measures the movement but doesn't measure, I can't even remember now what it was saying, but there was something that it didn't measure within the training that was missing, but you're able to get some of the movement out of essentially out of measuring.

So is there maybe something that you believe should be manipulated or how it should be manipulated, especially within a class structure where it might be quite difficult where obviously you've got a lot of different fighters going at once, you may be going training different skills each day or even separate parts of the day? So maybe you need to do some kind of intensity within this skill and this skill. So is there maybe a way that you like, that you would see as a good way to represent a training week?

Dr. Chris Kirk20:36

Well, I think you've hit the nail on the head for the problem for most MMA gyms and MMA is a sport overall, the fact that you might have 40 people on the mats training at any one time. Of those 40, there might only be 10 who are active competitive fighters. And now I'm not talking about American Top Team, I'm not talking about American Kickboxing Academy, I'm not talking about the big ultra gyms and they're the 1%. I'm talking about the 99% of all other MMA fighters.

You could have 40 people on the mats, 10 people who are fighters, and three of those people are getting ready for fights. One person could be getting ready for a fight in two weeks' time, one person could be getting ready for a fight in a month's time, and one person might have only just booked their fight three months down the line.

So if we have an environment where everyone's doing completely different things, three quarters of the people there are paying customers who are keeping the lights on, and only a quarter of people are there to actually get better and become competitive fighters, the coach has a really, really difficult job to do there.

How do you bring in these changes and undulations in training load? It's not like working at a football club or rugby club where everyone's on the same timetable and need doing the same thing. So that's a really big problem.

Now, what we also found in the training load study was that we were able to differentiate which types of training were more and less intense. So we split it into jiu-jitsu style training, striking style training, and wrestling style training, just three basic elements of MMA. And then we had the same three things again but for sparring.

Now we found that the most intense type of training was obviously MMA sparring, wrestling sparring, and wrestling drills. The two least intense were striking drills and Brazilian, and the jiu-jitsu drills. But the jiu-jitsu drills were as intense as the striking drills, but the coaches and the people in the sport, and myself included before this study, the view is that the jiu-jitsu sessions are the least intense and that the jiu-jitsu sessions are about far and away the easiest sessions. But actually the jiu-jitsu sessions are as intense as striking drills and are not that less intense than wrestling drills.

So we use the RPE scale for to determine the intensity of the each individual drill, and I can't remember quite off the top of my head, but I think jiu-jitsu drills came in at around about a four on the RPE scale, wrestling drills were only a five. So there's only one AU above, but people view wrestling drills as being ultra intense, jiu-jitsu drills being the easiest thing we do.

So what we found in each session where there was jiu-jitsu drills, they do a longer, a long duration of jiu-jitsu drills and a really short duration of wrestling drills. But because of the way the sRPE method of measuring internal training load works, they were getting the same load for both of these things. So that's what I think was the core of this flat loading pattern across the week.

You'd have, for instance, Tuesday where they're very much focused on jiu-jitsu, and then Thursday they're very much focused on wrestling. They do short wrestling sessions, long jiu-jitsu sessions, but the load balances out. They're essentially getting the same training dose on each day.

So I think that in order to bring about those changes in training load, I think if coaches are given a better understanding of how intense each type of training is and how we can use the durations more effectively within the normal class structure, that could bring about that undulation. And if you've got, let's say, out to those five fighters who are getting ready for a fight, you've got two guys who are getting ready for a fight in the next couple of weeks, then maybe we could develop a system where we're able to say, okay, so you two guys are getting ready for a fight in three weeks, your intensity needs to be going up or your volume needs to be going up.

So you guys are going to do two more rounds of these wrestling drills whilst everyone else is stretching off, you guys do another 10 minutes of these wrestling drills to get that volume up a little bit more, to get that intensity up a little bit more. If you need to do your pre-fight taper intensity, get it up to a nine or a 10, okay, you're just going to do wrestling sparring, you're just going to do two rounds.

I want you to go as hard as you can in this wrestling sparring, try and keep it at a nine or a 10, and then you're done for the day. You guys just do the first hour and then go.

I think that is our starting point for figuring out how we can manipulate the technical tactical training to bring in those undulations that's just based off the data we have in the moment. Whether the system works in practice, we've got another 10 years of research to do on that yet.

James de Lacey25:20

I'm sure you can also, I guess, manipulate training partners as well, right? So if one's needing intensity, you bring in someone a similar skill level that they often train with that they like. For example, as people who maybe practice combat sports, you know there's certain guys you train with that you can get really good, I guess, rounds with, and there's other guys that aren't as good, you can almost just relax and chill. So you can almost manipulate intensity that way too, but obviously that takes more planning and being out, you know, having everyone there as well. So that's obviously another factor.

Dr. Chris Kirk26:09

And with that, and that would absolutely be a useful method as well, but then you've got, then you kind of restricted as to where the person is living in training. So if you're at a club or a gym in a big city where there's six or seven other MMA gyms, then you are going to be able to travel around quite easily and find those people who can push you around.

Where I live, it's a lot of small towns dotted around with only a couple of MMA gyms between us, so people have to travel long distances to get different partners who can really, really push them. But that's why when people turn pro and they start getting up to that point where they're getting noticed by Bellator, PFL, UFC, that's when they tend to actually move to the bigger gyms anyway, because they have to get those training partners who can push them and make them more intense both on the skill and fitness level.

James de Lacey26:58

Yeah, for sure. Now I love the idea of using accelerometry within combat sports. I believe that's almost the future of at least the research, because as you mentioned there's nothing there. Every other sport has a time motion or neat analysis on them, you know, they cover this much distance, this in blah blah blah. Combat sports just don't have it, and I think that's something that will come future.

But I think it was on the paper when you mentioned about the accelerometer, it doesn't measure strikes. So obviously you can move around, if you're throwing a punch it's not going to pick that up as essentially a load on the accelerometer. So I guess is there anything, I guess, being developed in that area to be able to really quantify what happens in training or in a cage or whatever?

Dr. Chris Kirk27:23

Yeah, so the accelerometry I think is a really interesting area for us to go down. And for the listeners who haven't seen the detectors we're talking about, the ones I use by a company called Catapult, and they're about...

James de Lacey27:54

Yeah, I've got the shirt. I got the shirt yesterday, so there you go.

Dr. Chris Kirk27:54

Nice. Yeah, people from Catapult, if you're listening, I've done loads of promotion for you guys. I've not got any merch yet. Where's my tee?

So the accelerometer, it's about that big and it sits just in between the shoulder blades in a harness. Anyone who watches rugby union will have seen these.

Seen the lumps in between the players' shoulder blades. That's essentially what the players are wearing. What it allows us to measure is how much change and acceleration the person's body goes through while they're playing their sport, which is really useful for a sport where distance doesn't matter, such as combat sports, where time of movement doesn't necessarily matter, but actual movement does. So we've done three or four papers now using accelerometry and found it that it is reliable for measuring how much movement they do during a takedown, during a strike, and during submission movements on the ground.

We have a study that is currently—we're in the process of currently writing up another study where we try to compare the accelerometry data to the rating of perceived exertion data, so the internal load to the external load. And we're finding fairly solid relationships between the two, so anything from on a correlation scale anything from 0.9 down to about 0.6 is where they tend to be. The lowest ones, however, are in the grappling where it's around about 0.6.

Now, the reason we think for that is because the accelerometry—sorry, the accelerometer, the Catapult units—were designed for Aussie Rules Football and rugby. So two sports where the people are on their feet running around a lot, not a long amount of time spent on the ground. There is some time on the ground obviously, but as soon as a player can get up, they're back on their feet and they're running again.

So the actions on the ground, where you're grappling with someone, you got someone in your guard, avoiding punches, trying to control their arms, your torso is not moving that much. But you're working really hard. You've got a lot of asymmetric movement in your legs to try and hold guard. You've got a lot of asymmetric actions on your arms trying to pull their arms down.

You got a lot of head movement, a lot of hip movement, but your torso is not moving. So we find that the accelerometry is great for measuring large movements, but the asymmetric actions, the small limb actions that are vital and are really difficult in the jiu-jitsu side of it, they don't get picked up so much by the accelerometry.

So what I'd like to see if we can do is develop different algorithms to fit onto the accelerometry data that will allow us to match up if someone's spinning for an armbar, whereas someone's trying to get in position for a sweep, or someone's literally just moving their head trying to avoid getting struck in their guard—can we pick out those actions in the accelerometer trace to make it a bit more accurate? Whether it's possible, I don't know. I've seen a few different studies that they've done in discus throwing where they were able to pick out the accelerometry readings that will tell you whether a discus throw is correct or not.

But that took years of biomechanical studies using force plates, using motion capture cameras. And again, during a discus it's one movement. You'd have to do that same thing for someone getting up from guard, someone going for a sweep, someone's armbar, someone punching. Whether that's possible or not, I don't know.

I am aware that there is a company that has developed an accelerometer that would go under the hand wraps in the boxing glove. And apparently they've got fairly good reliability data that they can recognize when you're throwing an uppercut or whether you're throwing a series of crosses, whether you're throwing a hook to the body, whether you're just covering up.

But they're very much—I don't know if they're fully validated yet, but they have been shown to be reliable. But they're reliable only for stood-up boxing actions. You'll know a boxer stands like that, an MMA fighter stands like that. Two different movements. Are the accelerometers reading those actions differently?

So I agree. I think accelerometry is one of the key methods that we're going to have moving forward for combat sports. Is it ever going to be perfect? No. But is there anything else that we can do that's going to give us as much information, like the movement, as accelerometry? I don't think time-motion analysis gives it that accuracy. I don't think video analysis gives us that accuracy. I think accelerometry is the way to go, but there's quite a lot of work to do in that field as we currently stand.

James de Lacey32:15

For sure. Could you wear potentially the wrist-worn accelerometers plus the one on the back to potentially marry that data up? Because then you're getting the torso and arm movements. Maybe, I'm not too sure, but that could be something.

Dr. Chris Kirk32:43

Yeah, absolutely. And again, that would be work to try and marry up the actions that we do accelerometers to see what's the final output number. And I know there are also accelerometers designed for soccer now which fit—I think at the moment they have them set up so they fit around the boots, but I think they're trying to make them smaller so they can fit inside the boot. And for football, it's looking like those are more accurate than the torso-worn ones, determining how fast someone's moving and when someone's moving.

So these things have been developed all the time. They're getting better and smaller and more accurate all the time. It's just going to take a bit of work to figure out how they apply to what we want rather than what football, rugby, Aussie Rules, or what the—I guess—the cardio kickboxing people want. Because there's a million now, like, punch trackers out there. But yeah, I don't think they're good enough for this, unfortunately.

James de Lacey33:10

No, it's like the difference between your Apple Watch and your Garmin. They're two different things. They're two different markets.

You mentioned as well about the breath hold stuff. Did you ever go down the rabbit hole on there?

Dr. Chris Kirk33:34

Not the breath restriction. Breath restriction on—the how you mentioned at the beginning of your master's how you was an AstraZeneca?

No, I just did a little bit more reading around what they were trying to do. And it's nonsense. It's not going to help, basically. So if—so the—you see a lot of these POWERbreathe. Yeah, there's a power train. I can't remember what it's called.

What those are able to do is essentially you're doing weightlifting for the muscles around your rib cage. So they allow you to strengthen the muscles around your rib cage, strengthen the muscles around your diaphragm. But it's not going to do anything to affect how well the lungs work or how well your body can utilize the oxygen it's bringing in or clear the carbon dioxide. It can't affect that in any way, shape, or form.

If someone's coming back from an injury where they've been sedentary for a long time, it can be a good starting point before they get back into full training. And I believe there are some modalities that swimmers use to reinforce them being able to hold breath and really expel. But it's very much a short-term thing. As far as improving VO2 max, improving high-intensity performance, unfortunately they do nothing.

James de Lacey34:59

Okay. So they're not going to help you breathe, I guess, better during hard sparring or whatever it is that people say. Or I don't know what else—I don't know what other claims they make on it. But I guess most people try and use it to—I don't think they use it when they're training now. I think they use it separately, right? It's like a separate training session on its own.

Dr. Chris Kirk35:27

Yeah. I think the way the manufacturers say to use it is on your own, sitting in front of the TV, doing 30 deep breaths on the machine. There are some modalities I've seen in swimming where in between their lengths, they will pop their head up out the water and have two really hard pulls on the POWERbreathe.

But again, that's very much training of the diaphragm muscles and the muscles around your intercostal muscles. But if they're already strong, if they're already able to get your lungs up to their maximum capacity, that's as much as you're going to need. You're not going to get any further benefit.

James de Lacey35:52

Okay. Now that's good to know. So essentially, if you're already training, if you're already reaching max heart rates or hard training, you're already getting—you've already developed that essentially that strength of those muscles around the rib cage.

Dr. Chris Kirk36:21

Yes. So if you've got—if you're already trained to a point where you can get as much air into the lungs as can possibly fit in your lungs, then yeah, you're already at the point you need to be.

James de Lacey36:21

Gotcha, gotcha. I want to come back to the training week stuff as well with the periodization. So just based on that research and maybe your own experience as well, what would you—let's say best-case scenario of how a training week you believe should look that would create that nice undulation? I guess for someone who has an unlimited, flexible schedule and can train whatever part of MMA they want to on any time of the day, how would that look to you?

Dr. Chris Kirk36:45

I believe that things should be as simple as possible, especially in a sport like MMA or any combat sport, where you are only preparing for one day that's three or four months in the future. So like in team sports, they've got to play two games a week and they've got to be ready to go every couple of days and train around those as well. Sorry, one moment.

So in team sports, you have to have quite complex periodization programs and have it very finely mapped out. In MMA, I don't think we need that complex periodization structure. I think generally speaking, there are four things that fighters in MMA are trying to train: their submission skills—

Their wrestling skills, the striking skills, and then how can they put it all together in sparring. I think we're really covering those four areas. So I personally think the easiest way to do it would be to pick two days of the week which are about the most intense days.

So one day where you're spending most of the session in some form of sparring—that could be MMA sparring, it could be wrestling sparring, it could be kickboxing sparring, it could be just jiu-jitsu sparring, because all are the most intense types of sessions. We could get into a conversation later on about how much MMA sparring and kickboxing sparring people should be doing for head impacts for wear and tear. But I think generally speaking you want one day where some form of sparring is being done, and then another day earlier on in the week where you're doing the more intense drill-based categories.

So wrestling drills and a mixture of BJJ and striking drills, but done to the upper limit of their intensity—so around about a six or a seven on the RPE scale is the upper limit for those types of categories. The rest of the week should be done around moderate to light intensity. So having, prescribing striking drills to the lower end of the RPE scale, around about a three. Grappling drills where it's to the lower end of the RPE scale for grappling, around about a two. And mixing up those lower intensity drills around the low intensity days.

And having two days a week really targeted on: this is where we're going to go hard, these are our intense sessions. There might only be an hour, but in those sessions we're going for it. I think if you get that simple week structure set up that fits the fighter's requirements and the gym's requirements in terms of when the coach is there, how many other people are going to be on the mats, then you can manipulate each of those days to bring the between-week undulation up.

And from there onwards I think it's simply a case of changing the volume. So if you start off on week one, the volume of grappling drills and the volume of sparring rounds is down here. Week two, just increase it a little bit. Week three, just increase it a little bit. And then the same on the next mesocycle. Rather than increasing the volume, we're going to go a little bit more intense. So rather than having the striking drills around a three, okay, the striking drills are around about a four on the 0 to 10 RPE scale.

I think having a simple, almost a linear block structure based around just manipulating how intense or how much work we're doing on each of these days, with two days a week where they go intense, I think that would be a really simple way of building periodization into the coach's technical tactical dream and the fighter's technical tactical dream. And that's even before thinking about the strength and conditioning work that they would do alongside that.

James de Lacey40:50

Where would you put that in that kind of training week?

Dr. Chris Kirk40:50

So the two intense days we've already marked those out of—we got a sparring day, we've got a heavy wrestling day. So we would just have their more intense S&C sessions. Even if the fighters can only do two days of lifting per week, we just shuffle them 24 to 48 hours away from the most intense technical tactical days.

Again, I don't think it needs a complex strategy. I think it just needs to be very basic along the lines of how would you set up a dead basic strength and conditioning plan. If these are the most intense days, I don't think we need to go more intense than that.

I think the more difficult side of the S&C is: when are they going to be doing their conditioning? When are they going to be doing their cardio work? What is that going to look like? Which methods are going to be more appropriate for them?

And from what—well, just going back to the training load study that we did, I think we had 408 individual training sessions that we analyzed. Only 63 of those were strength and conditioning sessions, and of those 63, I think 70% of those strength and conditioning sessions were done by one person. What we found in this study was that MMA fighters don't really do strength and conditioning. They don't do the fitness work alongside it. And there were no sessions in the sample we had that could be described as cardiovascular training.

So I think where it will get more complex is figuring out what type of cardiovascular training is going to complement the work they're doing on the mats and how can we build that into that training week.

James de Lacey42:17

For sure. And you obviously mentioned as well about the taper, because obviously you talked about now increasing volume, increasing intensity. And then within your study you had fighters just literally just take the last week off and that was it, and everything else is the same. I guess you mentioned obviously having a two-week taper. Do you want to maybe run down how someone listening to this could implement the two-week taper going into a fight?

Dr. Chris Kirk42:43

Yeah, absolutely. So I think a caveat at this point is to say that the two-week taper is entirely based on the classic tapering literature that's out there, which—and all of that information is based almost entirely on heart rate and lactate readings taken from endurance runners. Okay, so when we talk about that two-week taper for most sports, it's very much a case of: well, it works for endurance runners, so we're going to kind of just trust that that's going to work for most of the sports.

With, again, the dark secret of sport science is that's kind of what a lot of sport science is based on. It works in that sport, so we're just going to kind of assume it crosses over to this sport.

So for combat sports, there's virtually no data on—virtually any data that shows that a two-week taper is appropriate. The only thing that I can think of that really does lend credence to the two-week taper being appropriate was a case study by Israel Halperin, who tracks a boxer—just one boxer—getting ready for a professional bout. And throughout the camp they did a series of measurements such as jumps, sprints—I think they did a punch speed test as well. That might have been with the Lyontrends, so I might be getting mixed up with another study there.

But they took a series of measurements and the fighter did their normal weight cut, got ready for the fight, had the fight. But their performance on each of these measures only peaked four days after the fight occurred. And the fighter did, I think, a seven-day taper. Just in the normal training they—Israel didn't manipulate their training anywhere, they just let the fighter do what they normally do.

So if we're talking about having a two-week taper and that boxer's performance, physical performance, peaked four days after the fight after a seven-day taper, that kind of fits in with a two-week taper. So if we're going to work on that two-week taper, what we normally tend to use is: keep the intensity of the work high, as high as we can, and then have an exponential rapid drop-off in the amount or volume of work that that fighter is doing.

So if we're looking at the technical tactical sessions, again, I think it's relatively straightforward. If we have those two intense days, then for that final two weeks those two intense days, right, we're going to have you working at a nine or a ten. So in your sparring, if you want to carry on sparring for those—well, again, we don't have to do MMA sparring, it could be just all-around wrestling, sparring. I want you to go at ten and you're going to do two four-minute rounds, and that's your entire session. So it's chopping off the volume, but keeping the intensity nice and high.

For the drill sessions, if we're doing striking drills, I want you to work at six, which is roughly the upper limit of what we saw for intensity of striking sessions. We're going to work you at six with these striking drills, but you're only going to do half an hour. That's your session done. So I don't think it requires a very complex method. Just work hard and just drop the amount of work you're doing. Just less time in each session.

And one of my supervisees, one PhD, Dr. Carl Langan-Evans, who does a lot of work with current UFC fighters from the Liverpool area, and that's the basic premise he's been working on for a few years. And he's been getting some really good results, both in terms of when the athlete's physical performance is peaking and how they're feeling approaching the fight as well. They're going into that final week weight cut not feeling drained, not feeling tired, not feeling like they've done too much.

They're, if anything, they're doing a ten-minute intense, ten out of ten intensity pad session and walking away going, 'I've got more in the tank. I've got more to give,' which is exactly where you want them. You want them going into a cage thinking, 'I've got so much more to give. I've got so much more to do,' rather than thinking, 'I just want to get this over and done with. I'm dead on my feet,' which is what we see from most fighters. So I don't think it requires a very complex model. We've got the basic model of intensity high, drop the volume. Let's just follow that.

James de Lacey46:38

That's such a great place to be, psychologically as well. There's some good research as well around fatigue. Obviously fatigue is multifactorial, but that psychology component is one of them, where you're basically comparing the perception of the effort you're doing now compared to previously. So if you've previously—if

That used to be really hard, you're out on your feet, you're like that's tough. And then you come in close to fight week and you're doing a similar session but you're stopping it and you're feeling like man, I can keep going. That's a huge psychological win for yourself as the fighter going into whatever, knowing that hey, I can give these efforts and I've still got a lot more to give as well. So obviously that taper helps keep that energy there so you're not feeling drained after everything you do.

Dr. Chris Kirk47:28

Yeah, absolutely. That psychological burden, you speak to so many fighters and so many of them will say they went into most of their fights thinking I don't want to be here, I just want to get this over and done with and finish it and then just go out with the lads or whatever. And that continuous psychological burn of oh I've got to do this fight, I've got to do this fight, I've got to do this fight, that's going to add up more and more over time.

Whereas just for their mental health, if they're going into the fight thinking yes, now this is what I'm here for, this is the bit I love, that is only going to help them with their mental health over the course of their careers as well. So we do have to think about that alongside it.

James de Lacey47:56

Yeah. How, I guess during the taper then, say the final week, obviously maybe the acute weight loss strategy starts coming in, I don't know, three days before or something like that. I guess would you stop the intense short sessions then, or is there some kind of other manipulation you're doing then regarding the volume and intensity as you get to maybe acute weight loss strategies?

Dr. Chris Kirk48:19

Generally speaking, what we see from MMA fighters is that the worst part of the weight cut is that 36 hours before their final weigh-in, that's when the dehydration methods really start to kick in. And in my opinion, so long as you do a very short but high intensity workout the day before they start in that final dehydration to really drain themselves down, I think that's as close as you want to get.

But again, it could just be a case of 10 minutes all out on the pads. It could be a case of 10 minutes all out in the gym doing trap bar jumps with a heavy load, two sets of one, it could be something as simple and straightforward as that. But yeah, you definitely want to avoid any work once they start in the dehydration phase because that's a horrible couple of days for the fighter anyway. You don't want them worrying about doing extra work alongside that.

And if you look at the work of Carl Langen-Evans, he did a paper last year with the Taekwondo fighter, that's an approach he took and got great results. And he gets great results in practice with that particular strategy as well.

James de Lacey49:43

Oh awesome, I'm going to have to go look at those papers. I'll get you to send me some of those papers, link to those papers, and I'll definitely go check them out.

Dr. Chris Kirk49:43

Absolutely, yeah, perfect.

James de Lacey49:43

I think we've actually covered everything I had questions-wise about. Is there anything else you wanted to add to the conversation, maybe for anyone listening? And then if not, where can people look to follow, I guess, what you're doing, your research and everything else?

Dr. Chris Kirk50:09

Just on the weight cutting side of things, I would like people to understand exactly what's happening to the fighters when they are doing their weight cut. We always, and this is from a fan standpoint, we always tend to get into conversation of a fighter misses weight or they're unprofessional, they've not tried, they've not done this, they've not done that.

MMA fighters take weight cutting to the absolute extreme. A rule of thumb, they're cutting their body mass by 8 to 14%. Boxers are doing about 5%, wrestlers are doing about 3 to 4%. The physiological toll that fighters are experiencing through this weight cutting practice is huge and it is life-threatening.

So I think from a research standpoint, we've got a lot of work to do in order to bring about safer methods, both in the short and long-term safety, and to help their performance. From a fan standpoint, I think we just need to look at what these fighters are doing and give them a bit of slack when they do miss weight by half a kilogram or a kilogram, because they are literally taking their bodies to the absolute limits of what is safe and healthy. And in fact, for most, is beyond the point of safety and healthy.

So from a fan standpoint, if you see a fighter struggling to make weight, just have a bit of compassion for what they're doing and what's happening to them at that point.

James de Lacey51:14

In terms of, if people want to contact you.

Dr. Chris Kirk51:41

Yeah, if people want to contact me, I am on Twitter, which is ChrisKirk_ASP. That's also my name on Instagram, but I can't figure Instagram out, so you'd be better off contacting me on Twitter. Instagram does not work for me.

In terms of contacting me by email, please feel free to contact me on my email address, which is c.kirk@shu.ac.uk. And if you're a fighter looking for advice or looking to work with me, contact me on that email. If you're someone who wants to get into research in combat sports, if you're interested in doing a PhD or a master's studying combat sports, contact me. We'll see what we can get set up for you at Sheffield Hallam. I'd very much like to chat with anyone who's interested.

James de Lacey52:07

Awesome, that's a lot of good stuff for anyone listening who wants to maybe get involved or contact Chris. Well, you got his direct email there. I'll put everything in the description too, so you can go in there and see it too. But I appreciate your time, Chris, and thank you for coming on.

Dr. Chris Kirk52:35

No worries, thanks for having me, James. Very much enjoyed it. Cheers.