Decoding Olympic Weightlifting Biomechanics w/ Kristof Kipp (SSOF Ep 201)

Kristof Kipp1:09

Done in recent years, we've also done some similar testing at the Olympic Training Center in Colorado Springs. There we don't quite have the force plates, but again we have access to a pretty large weight room and we're able to set up our motion capture equipment to be able to record in pretty high fidelity data of the lifters doing their sort of full-on competition lifts.

James de Lacey1:13

Are you also part of the research group that does the same thing at the IWF Worlds where they have the platform with the force plates in them?

Kristof Kipp3:46

I would say, I think you're thinking of somebody different and I'll come back to this. So there is a, I'm trying to think of the order in which to describe this right. So yes, there is a group that collected force data at the Worlds in Bahrain and in Florida. So the last two World Championships and that I don't want to say if it's led by Marco Sorano out of Spain who's a friend and a colleague but he also works with Hawin Dynamics which is the force plate company that supplied I guess the force plates to do the testing.

And so in Bahrain, Marcos did jump testing with the lifters there. I don't know if they did, they may have done some isometric pole testing as well. But then last year at the World Championships in Norway, Hawin Dynamics also rolled out a prototype of a force plate analysis system that you can use to analyze actual lifts and different variations of the lifts.

So not directly part of that group. Marcos and I have collaborated and we've tried to work on a couple different analyses of some of the data. I'm not the one that's doing that testing, but that's that's him. And then I would just say I've collected some additional biomechanical data during the competition. Specifically at last year's Worlds and maybe that is coming back that the instrumented platform that Hawin Dynamics currently has as their sort of prototype model is not approved for competition. It was set up in the training hall.

James de Lacey5:37

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All right. I want to try to get down to the nitty-gritty, but I want to try to do so in a way that doesn't give you such broad questions, but it might end up being broad anyway. But I really want to go into what you're really seeing during these lifts and what the data you're pulling out from it and then how that actually changes anything.

Cuz obviously in the world of sport science, we can get caught up in data, collecting data for whatever reason, and then you just have data for the sake of having data. So, I'm interesting to kind of know, you know, what you're pulling out of this and what is meaningful to you in terms of maybe lifting performance?

Kristof Kipp7:08

Yeah. Meaningful to me or to the athletes and the coaches. And that's not always the same, which is sort of interesting. I definitely love to get nerdy about specific biomechanical variables, but I think we're very much aware that I mean the reason that we're able to do this work with USA Weightlifting and we briefly talked about this with throws as well, right, with some track and field throwers is that at the end of the day, we do try to make some of the data translatable for coaches and the athletes.

James de Lacey7:15

Well, that'd be interesting to go into as well.

Kristof Kipp7:17

Yeah. When we do for example generate reports on the training camps, the high performance staff is always very much focused on what are the ultimate takeaways from this. What do we see? So I mean I guess we could run through some of the testing that we do that we've done. And I know you mentioned an interest in some of the vertical jump testing that we've done.

And so the vertical jump testing we use as an idea of what's sort of a neuromuscular capacity, a test of neuromuscular capacity, doing a very dynamic task. A lot of research has shown that vertical jump capacity is related to weightlifting performance, which is not really that surprising. You're an explosive jumper or you can jump high, must mean you're quote unquote explosive, so you're probably a good weightlifter.

In some of the work that we've done, we've been able to tie some of the vertical jump measures to specific aspects of the ability to generate velocity during the pole phase of the snatch and the clean and jerk. So that's probably a little bit more getting into the detail there is that specifically sort of first pole velocity generation, second pole extension. So the velocity that somebody's able to add to the barbell during those phases seems to be related to their vertical jump ability.

Velocity during the transition phase, which is getting a little bit more technical to weightlifting technique, does not seem to be related to vertical jump performance. It does seem like that specific phase is more constrained by technique and maybe some other factors. And that's important in the sense that velocity loss during the transition phase. So the transition phase, lifters typically have an initial knee extension off the floor. They rebend their knees slightly, knees come forward, the torso gets more vertical and some lifters will exhibit a decrease in the velocity trace during that phase.

And so how the lifter was able to manage that seems like it's much more related to their coordinative ability rather than sort of maximal power output. We also have done some sort of max level capacity testing. So I mentioned the isometric pulling test. We typically measure the isometric pull during the start position. So you can think of the bar basically loaded with not quite 1,000 kilos, but it's super heavy and we say you try to pull it as much as you can and we measure the ground reaction forces.

So during that test, we're able to see how much force are you able to put into the ground in the starting position that the lifter is in. And we can then correlate that against the ground reaction forces the lifter produces during the actual lift. So it gives us a here's the ceiling. Here's how much you actually need. Does the lift-off actually constrain you based on your pulling style or your pulling technique.

And so what we see is that some lifters have a pulling profile where the initial acceleration or the initial force produced during lift-off is very much a characteristic of their style, their pulling style. Some might say it's, oh, you just grip and rip right from the floor. And if that's your pulling style, then looking at the capacity, how much capacity you have might be an important thing to say, this is part of your technique. You're really close to your maximum limit. So, increasing pulling strength off the floor might be, it might make sense to focus on that in the next training cycle.

And I do try to hedge these takeaways slightly. So you might hear me say it's, it might be helpful. You may want to look at this. And that's typically because we're dealing with obviously members of the national team, pretty high elite level lifters. And so they're all outliers in a sense on in their own right. They're obviously successful in what they do. They've made it to that level.

So, I think we often start these conversations with, here's what we see. Here's what the data sort of shows to me as a biomechanist. This is how I think about the movement. Does that pass the eyeball test from the coach? Does that sort of match with maybe their technical model, their technical style of lifting, the grip and rip. I think it's an easy way to sort of just say, oh, that's all you're doing. But I think some lifters genuinely prefer to just get the bar moving off the floor.

And we actually do see two different, I should say it's not two different pulling styles but it's definitely a continuum. Some, I mean ultimately what the lifter is trying to do is they're trying to impart enough momentum onto the barbell so it has enough velocity that it travels a certain height they can drop under it and support the barbell at shoulder level or overhead.

Some lifters will reach that sort of threshold velocity in a very small amount of time and they'll produce just a lot of average force. And so we would say quote unquote it's an explosive pulling style. A lot of force, short amount of time.

And on the other hand, we have some lifters that if you look at them, you're like that looked like it took forever. Even though it's only 1 second, but it's still almost a third longer than some of the other polar, than the other lifters. And so some lifters will have a rarely prolonged pull and they get away with using a low amount of average force.

And that's sort of this continuum that we've actually been able to sort of tease out even at the elite level at the World Championship level. We see it in most of the national level lifters as well. And maybe coming back to your point of how we talk to coaches then, we're able to characterize somebody's pulling style as an example and say, this is sort of your fingerprint.

This is where it matches up to what we see in other lifters in your category, accounting for body weight. Here's what the top three at Worlds did, our medalists. This is what top eight were sort of doing. And then this is where you would fall in terms of that pulling style if you will.

And yeah, I think sometimes that leads coaches to think, yeah, does that pass the eyeball test? Having data across three lifts in competition is sometimes helpful, is that if you see if somebody makes a 2 or 3 kilo jump we can see if their pulling solution gets constrained in the first pole or the second pole. So maybe they're fine during the first pole that they're able to break inertia off the floor by pulling just fine but they're not able to impart the same impulse onto the barbell during the second pole.

So that might be a focus then of, in training it might make sense to focus on that triple extension if that becomes a bottleneck to performance. Sometimes looking at makes versus misses can give you the same sort of insight as well. Here's two successful lifts, this is what changed and then all of a sudden during a miss lift we see an alteration here.

James de Lacey15:47

Nice. So if I was just going to put that bit into context, someone who doesn't have that same impulse in their second pull, they might be doing more hang work, block work, etc. Someone who maybe doesn't have it off the floor might be doing more kind of pulls from the floor.

And in terms of pulling styles, because you mentioned obviously you see it dramatically in competition, like guys, as you mentioned, they look like they're just deadlifting the weight and then suddenly they're under it versus the ones and you're like, how is that even possible? And then you obviously see the guys that are just like super fast off the floor and you're just like, "Holy, that guy, that way looked like nothing."

Does it potentially change the way that you maybe think they should train? Is there something like a different training style, system, whatever it is, that you would impart on those two different athletes versus maybe I'm not going to say one size fits all, but like a general weightlifting program?

Kristof Kipp16:44

Yeah. So I think there's like three things that came to my mind because they're great questions. Like one would be as we're collecting more and more data, people ask do you think we can actually quantify what's like the North Korean style of pulling? Like what does a certain country do if they have a centralized system? Within the U.S., you probably know it's quite different. There's no centralized training system. Everybody pretty much does something different, and by everybody I mean people on the national team, because everybody has their individual coach.

The other part to that was it's almost like a version of the strength coach question: do I train your strength or do I train your weakness? Again, if you have a quote unquote explosive puller, that might just be their superpower. And so we're going to try to feed that superpower without taking away anything from that, or while at the same time addressing some of the things that we would consider technical faults. It's a balancing act.

And maybe an example of that, that was my third thing, is that we would generally say if you are pulling the barbell off the floor with more than like 150% of force that's on the barbell or load that's on the barbell, so if you have 100 kilos and you're all of a sudden generating 150 kilos of force essentially, that's probably more than what you need, and a more measured pull might be better because it sets you up for better positions later on in the lift.

So if we have that sort of tracing of within the sort of path analysis model or within our technical model, and then we see when we do tests like say during a power variation and we say during a power variation that thing that you do that we are sort of little wary about actually gets accentuated, we're like we probably don't need to do more power variations. We need to spend our time on other things.

James de Lacey17:36

How, because you're not trying to rip it off, most people aren't trying to rip it off the floor, how are we then trying to quantify, as you mentioned, the velocity off the floor kind of correlates well with this kind of vertical jump, if I got that right? So because it's obviously not a maximum pull off the floor, is there something there that maybe you're looking at? I don't know what the question is here, but looking a little deeper or anything like that?

Kristof Kipp19:37

I think it's a good point again, and I think there are different ways to think about that sort of style and technique and approach to liftoff. I guess one thing I would say is that when we throw out these numbers and when I say there's a high amount of force during liftoff, it's a single number oftentimes. And it's easy to hang your hat on a single number, and arguably for coaches and even I guess in research sometimes, having a single number simplifies things down.

But we do look typically at the force and velocity profile throughout the entire pull through the pull phase, through the turnover and into the catch phase, with the understanding that or the appreciation that it's very much a dynamic process. It's not just force at one specific point, but what happens in between there, like what is the dynamic pattern that we observe.

And so in the reports that we generate, we often look at what we call the time series data, so data over time, what is the fluctuations. And I think that's actually where we find much more insight into technical differences or individual differences between people.

James de Lacey21:43

I'm going to go further down that kind of fourth time series, because it relates really well to maybe Olympic weightlifting as a training modality for other sports, maybe other qualities. But before I come to that, I want to just quickly go down the road of how are coaches currently using the information then that you're giving them? Do you have any examples of anyone that's kind of implementing or making changes based on the data?

Kristof Kipp22:09

Not directly, I guess. Again, we typically will present the, we have training camps, we generate our reports, we try to provide those reports to coaches or have one-on-one meetings with coaches and or athletes. As I said, it's typically left at here are some thoughts and recommendations.

Somebody asked me that the other day, like, well, what is one success story that you've had? And to be honest, it's not like a major thing where we had this biomechanical variable that we're able to measure and change it with training and add 5 kilo onto somebody's snatch. I think the effect that the work has is a little bit more diffuse in the sense that it's tough to measure in any single variable.

Ultimately, we hope that their performance goes up over time. That's probably, and for most lifters it does. And as much as I would like to take credit for, yes, we did these biomechanical assessments and now you're winning a medal at the world championships, it's much more of a multifactorial problem and then solution.

So I think the effects are a little bit more diffuse, but something that I think I've come to appreciate a little bit more is that we provide this information, it might not be that coaches make an immediate change, but maybe it helps them think about, as they're in practice or they're observing something maybe three or four weeks down the road, this sort of matches with what we talked about in that. So maybe, and ultimately I think the coach still has to sort of then translate that into a coaching cue or into they have to communicate that to the athletes.

Not weightlifting related, but in some of our work with track and field throwers, we've done some work, some recent work on trying to do more what we call sort of co, biomechanics and cue mapping, right, where we talk to coaches and say what do you see here, what's part of your technical model, does that map onto specific biomechanical things that we see. And so we try to map and connect the dots essentially.

And the value there is that again, sometimes it's not a specific thing that you're pointing to, but you're able to uncover whether or not certain coaching cues have a mechanical basis or whether they encode biomechanical principles that we know are related to performance.

James de Lacey24:28

I don't know if you're able to share or if you have any data insight, but what makes someone like Olivia Reeves such a freak in weightlifting?

Kristof Kipp24:28

Great question. So I think if you look at, I mean everybody, anybody who's familiar with Olivia as a lifter probably knows that she can squat a house, quite literally. So I would say not neglecting the level of strength. I think strength is like the price of admission. Strength is necessary but not sufficient. So she's very strong.

I think her sort of pulling style has become more efficient over time in the sense that she's able to lift more and more weight with slightly lower average force. So sort of going back to the pulling style that I mentioned earlier is that you could think of this as if my pull time or my pulling mechanics stay the same, if I need on average 130% of the force that's loaded on the bar, that's maybe a starting number, but if I can get away with 129 or 128, I become more efficient. So that's something that we've definitely seen with her mechanics overall.

And some of the other interesting bits is that I think she is super efficient. And that's, I don't know if I'm going to be able to back that up scientifically, but the way that she gets under the bar, the way that she's able to turn over the barbell is quite remarkable in the sense that once she's done with her pull, the way that she's able to reverse directions fast enough that she's actually able to leverage, or we call it trapezing under the bar.

She's able to almost use the barbell that's floating upward as a point of resistance or as a lever that she's able to pull herself under so fast that she's able to actually inject an additional amount of work into the barbell so that it continues traveling up to whatever height she needs the bar to be. And that allows her then to get into position fast enough to get ready for the catch.

And I think the way that she's able to sort of do that quote unquote trapezing under the bar, the fact that she's able to be aggressive enough to get in that position quite a bit, I don't want to say faster, but it's more dynamic than what we see in some other lifters. It's been pretty

James de Lacey28:26

Remarkable to see. Would you say that's a relaxation mechanism then? Like she has that ability to contract and relax faster than others?

Kristof Kipp28:36

No, I think it's actually the opposite. I think in order to do that, you have to, that's almost like, no, it's a reversal of direction, right? So it's the ability to go from everything is moving up, pulling hard up as fast as possible to then reversing that direction.

I actually had this conversation with a, or this realization and a conversation with a grad student at a conference recently where we were sitting in this room where people were talking about change of direction tasks, right? So more broadly like agility or cutting biomechanics and they're talking about this speeding up and slowing down and then changing directions and it sort of dawned on me that I'm like I think weightlifting is actually like the ultimate change of direction sport because you have to give it everything you got going vertically up to vertically down in order to prepare for the bar, like to meet the bar as efficient as possible.

And when I say efficient there, right, we obviously want to minimize sort of the drop height and the what we call crash velocity of the barbell as it comes down on you.

James de Lacey29:46

It's a good answer. And regarding I don't know if you have any insight to this, but obviously she is stupid strong. Not everyone can be that strong and there are very few guys and girls that can be as strong as her. Is there any insight into maybe what underpins her specifically?

It might be a tough, I'm throwing it in there.

Kristof Kipp30:14

I mean, I'm not that familiar with her training history, but I do want to say like she started training at a pretty young age, right? So early practice, early exposure to lifting probably helps, right? There probably is some genetic component to trainability to how much strength you can actually increase over time with training.

I think back to there was some work on lifters at I don't know if it was world championships or pan-American championships where they did muscle biopsies and looked at different isoforms of muscle fiber types essentially right the contractile machinery of our muscle fibers essentially and it was interesting that they found in elite weightlifters that there's a really high proportion of these isoforms that are super fast muscle fibers.

So I think there is and the question is right is that something that you can change with training? Is that something you're born with? But there's probably this sort of component that's related to that.

But because you're in a sport that is sort of governed by weight classes, right, there's obviously something else that can't be explained by just muscle function because you're topping out at some point, right? Like you can't gain any more muscle mass. So we would then come back to it's either sort of a technical change or maybe it's related to neural control of movement or broadly maybe some people would say like motor control of motor units right some more physiological mechanisms.

And I want to say it's actually Marcos Sorano who I mentioned earlier mentioned to me that he's like maybe it's just that we haven't, we don't really have the tools yet to study that sort of neural control, right? We have EMG that we can use to look at muscle action potentials, firing of muscle fibers, but right that's a very sort of, it's a bad pun, but like surface level analysis, right, of muscle function. So maybe there's something deeper that we just don't, we're not able to quantify at this point.

James de Lacey33:00

Nice. And I wanted to go into a little bit of Olympic weightlifting for performance training and I'm sure this has come up a lot. It's the never ending debate within sport, you know, Olympic lifts versus jumps and plyometrics, all that kind of stuff.

So it'd be really cool to kind of go into because you have a ton of data on jumps and weightlifting to go into the actual differences between I don't know various Olympic lifts and then maybe just like vertical jumps or maybe short ground contact plyometrics and we can talk impulse velocity all of it.

And if if there are if it's maybe one can be replaced by the other or you're really getting different outcomes of potentially different adaptations from a limitless versus more ballistic actions or other ballistic actions, I should say.

Kristof Kipp33:48

So I will be the first to admit that we're so probably steering away from my area of expertise slightly. We did spend, I guess early in my career we did spend a lot of time relatively a lot of time looking at the mechanics of different types of resistance training exercises and trying to make those comparisons of like cross-sectionally.

I think that you're alluding to, if we have, right if you're designing a training program and you would like to fill that program with different exercises, we pick the exercises based on the adaptations that we're trying to elicit, right? So is it strength type adaptation, quote unquote power or speed strength?

Some of the early work, right, suggested that if you want to train power, right, so this combination of force production and speed production, it might make sense to pick exercises where you're actually during the execution of the exercise where you're trying to, where you're expressing the maximum amount of power output.

And so, right, we looked at different types of resistance training exercises. The interesting thing about weightlifting exercises has always been that you're right. The overall power outputs are much much higher than any other resistance training exercise that we have access to that you have in the toolbox.

Essentially the other interesting bit is that they're higher power outputs but the power outputs are also or maximum power outputs also reach at a respectively or a relatively higher percentage of your 1 RM whereas like a bench and a deadlift or sorry a bench and a squat right your maximum power output might be between 50 to 60% of 1 RM whereas for weightlifting type exercises it's 75 to 85, maybe even to 90% of 1 RM depending on the skill level.

So that's where I think right resistance or weightlifting exercises have, and then I guess I should say then at those sorts of levels right I think you're also optimizing for other things like probably a little bit more broadly strength adaptations rather than just strength speed or just power adaptations and I think that's why we see in part this carryover from training with weightlifting exercises and derivatives to things like vertical jump performance.

I know I mentioned power a lot. Some of my colleagues might get slightly annoyed that we're focusing on power because peak power might not be the best variable to look at quantifying sort of the mechanics of different exercises. But I would say the same holds for when we look at things like impulse momentum, average force, velocities that are generated, right?

Is that for weightlifting exercises, I would characterize them, right, as we're able to produce a lot of force in very short amounts of time and still generate a lot of impulse. And ultimately, right, impulse is what determines performance in a lot of different sports and tasks.

And so when I think of weightlifting exercises, sure those exercises are characterized by that, but it's also almost like baked in in the sense that you're training your neuromuscular capacity in a way that enhances that most, right, that focuses on that sort of, maybe slightly coming back to the grip and rip right it's like you have to, when I think of weightlifting exercises and I teach a class here at Marquette University where it's weightlifting, it's like weightlifting 101 essentially anybody can come and we start, we have some people who have never weightlifted before.

I think it's a big realization for them to to think like okay in order to lift this load this high, I have to focus all of my effort into this, right, into this force production in a very short amount of time. And it takes a lot of concentration and mental effort, focus and determination, Dane Miller from Garage Strength, he calls it technical aggression, right, which is a term that I quite like as well.

So there's a technical component you have to be somewhat aggressive. And so again, you're producing a lot of force, short amount of time, large range of motion, a lot of muscle groups that are active, and there's a coordination component, right? It's not just pure extension. There is some rebending of the knees, repositioning of the torso.

And so overall I think all those things sort of come together is why weightlifting exercises are just probably the best tool in that toolbox that you have.

James de Lacey39:21

You mentioned when we talk about impulse and and then kind of that change in velocity, I guess if we come back also the for the force time I guess curves and graphs that you're taking as well. I mean, we could look at the potentially the differences in weightlifting potentially having a I don't know, a longer force time, like a longer time through that pool versus maybe I don't know, quick contact jumps or maybe faster vertical jumps or things like that.

Does that change influence anything? And maybe prescription for maybe certain activities. I don't want to give you the it depends on the type of activities sort of question or answer.

Kristof Kipp40:05

One thing I'll throw out is that I think I mean when we often times when we think of weightlifting exercises, we default to like cleans and snatches or power.

James de Lacey40:18

Because we can shorten that force time, go high blocks as an example to go really like short time frames.

Kristof Kipp40:23

Yes. But I would almost say like the one that the one sort of weightlifting exercise we should not forget about is actually the jerk or different jerk variations. And that's actually so coming back to your question around vertical jumping is that

The force time curve for the jerk and for the counter movement jump look almost identical, right? That we have an unweighing phase, an eccentric phase, and then a concentric phase. And then you think that with a jerk you're obviously overloading that same force time pattern by, you know, the factor of one or two depending on how much load you're actually using. And so training your muscles' ability to tolerate high stretch loads during the dip and drive definitely has carry over to other sort of activities.

And so I think we see much greater sort of dynamical correspondence probably between force time curves during the jerk and different jumping tasks. And the time course then matches up a little bit more as well, right? Like I said, a 1 second pull, you probably don't have people taking 1 second for an entire counter movement jump, but like a drive phase during a jerk, right? Might be on the order of 300 milliseconds. And that is again quote unquote explosive, right? Very high forces, short amount of time, a lot of impulse that you're generating there.

James de Lacey41:54

How do you see jump strategies on weightlifters? This is an observational thing. Where when you often when you see clips of weightlifters jumping, you see them descend really deep so they have all the time in the world to reduce their impulse on the way up, whereas maybe more twitchy athletes might have a faster descent and not go as low. Is that something that you see as a characteristic of weightlifters?

Kristof Kipp42:21

We definitely see a range of jumping strategies. Yes. And I think there are different reasons why, right? I think one easy reason that those differences exist, I think it's based on their sports background. So we have some weightlifters that come to, or some athletes who come to weightlifting from gymnastics, right? And those athletes have a tremendous ability to jump, to produce a lot of, I'll just leave it there. They can jump and land really really well.

Some athletes who don't quite have that same broad sports background, they, like we've seen them struggle even, like elite level athletes, elite level lifters, we've seen them struggle coordinating arm swing and counter movement, right? And that's again if you're not a basketball, if you're not a basketball or volleyball player, you may never really have to think about like how large of an amplitude do I go through that motion.

I would say, and then it's interesting that, I think it's probably, okay so I can, I'll come back to Olivia. One thing I distinctly remember when we did one of her analyses and counter movement jumps very early on is that her sort of unweighing phase, like dropping into the squat, just seemed almost sort of slow and, I say lackadaisical, that it's not a very aggressive counter movement. But her ability to turn things on, right, to slow down and generate force during the concentric phase was very impressive. I'll just leave it there, right?

Is that, and so we do see that in some lifters where I think that the counter movement sort of strategies that they exhibit vary quite a bit. Some use a shallow jump, some use a very aggressive jump. And the more aggressive that counter movement is, the more eccentric force they have to generate to slow their body down. But ultimately, right, what's important for weightlifting is how much concentric force or concentric impulse they're able to generate.

And so yeah, so we do see some variation on the front end, if you will, of the jump, and that's okay. And I think that's just related to personal preference, their sporting background, but then what ultimately carries over is the back end, the concentric impulse side.

James de Lacey45:11

Is that something that you're talking to coaches about potentially improving in terms of that concentric impulse? I mean, I'm assuming that just kind of comes along with the training itself anyway, but is that maybe, I don't know, maybe jumping training, like if they're doing jump-applied training, is that potentially being modified to be more concentric only, like seated jumps instead of standing jumps kind of thing? Does it go that far?

Kristof Kipp45:21

We had some of these conversations very very early on and we very very quickly realized that sure we could talk about this but we're not training jumpers, we're training weightlifters, right? So we sort of just left it at like this is sort of the unique way that this person jumps. If the coach feels like that they would like to use jumps as part of their training protocol, right, then there might be a few nuggets of information for them to take away from that.

So, if part of the training actually uses some sort of like you said squat jumps or counter movement jumps or different jump variations, here might be a few things that you could think about of optimizing their performance if you want them to jump higher. And then presumably that sort of builds on throughout the training program, right? You're able to jump better, higher, more regularly. So, over time, you accumulate those positive influences, if you will. But it's not to say that like you're a poor jumper, you better fix that or you're not going to be able to clean and jerk 200 kg, right?

James de Lacey46:50

Do you, I don't, this is going to be poorly worded, but do you care much about what happened or do you care much about the eccentric qualities of weightlifters maybe during these tests since the sport is so highly concentric-based, like when you're pulling from the floor, et cetera?

Kristof Kipp46:50

I think that's a really interesting question and I would say, should we care, should like, we care about their eccentric capacity? Probably. Do we, as in like me? Like we typically don't do a lot of eccentric assessments, right? Or looking at eccentric muscle strength or capacity.

There's some research from the 80s that actually looked at the tolerance of stretch loads under loaded counter movement jumps across the loading spectrum in relation to weightlifting performance. And one thing that they found is that there seems to be a correlation with things like jerk performance, which again is much more eccentric concentric dominant, I guess, or is characterized by much more of an eccentric concentric stretch shortening cycle than the snatch and the clean and jerk. And that, excuse me, that for jerk performance, yeah, the ability to tolerate higher, to tolerate loads under greater demands seems like it's something that was important.

And so yeah, I do think in these conversations if there's a limitation with somebody's jerk work, right, looking at sort of what are the, what is their ability to tolerate quadricep stretch loads with higher loads, I think is something that should factor into assessment and training to some extent.

James de Lacey46:50

Nice. You talked a little bit about the force vector stuff in the beginning as well. It'd be interesting to hear your thoughts on force vectors and transfer to different areas of performance. So, for example, weightlifting, well, most exercise in the gym actually loaded, we're looking at kind of like this vertical movement. Obviously, sprinting more horizontal. We can do sleds that may be more horizontally loaded.

Is there a specific trend? I don't know if you can ask this or not, but is there a specific transfer where if I'm training a vertical movement that I'm not going to get the same transfer from that to a horizontal, horizontal-based movement or vice versa or any others?

Kristof Kipp46:50

So, I know that the sort of force vector theory exists in that strength and conditioning space, and I would just like to say I'm not going to touch that with a 10-foot pole because I know people get all worked up about different pros and cons or yes and no whether there is transfer to that.

I guess I'll give you some thoughts is that yes, I mean force is a vector, right? So we know that there's a magnitude and direction. The direction is probably really important based on the task. I also think oftentimes about this idea that your ability to produce force might be, right, is a capacity related issue, but producing the force in the right direction is probably equally important and that's sort of related to maybe your overall coordination pattern. So right, when we look at force vectors I think it brings together these ideas of like capacity and coordination.

In weightlifting, even though we think of it as it's very much vertical dominant, right, in terms of force production, the ground reaction force vectors when we've analyzed those, we do see very specific shifts in the force vectors as the lifters go through the first pull, transition, and second pull, right? And what is important there or what's important to appreciate is that the direction of that force vector coming out of the ground underneath your foot essentially, right?

So foot center of pressure moves back and forth and then the vector points in different directions. Is that that vector direction can actually have a very significant influence on the leverage that each of your joints has during the movement.

Right? So it can confer different mechanical leverage at the knee versus the hip. And sometimes I think about this, depending on how we think about that leverage, is almost like a gearing mechanism on a bicycle, right? You can shift into low gear, high gear. So that might be important at different phases. And so what we see is that lifters control that very very tightly.

And so, whether, right, we haven't been able to do this quite to the same depth that we would like to do this, but I think it could potentially answer some of those questions of like why somebody, again not picking on Olivia, right, or trying to pick a different example or different lifter, but if you have a lifter you say why are they so efficient, right? Might it be related to how they control that ground reaction force vector.

And so we have the pull phase, we have the sort of turnover, going into the turnover, right? You're controlling your body in addition to the barbell, right? The overall motion of that system is going to be dependent on how well you're controlling that ground reaction force. Same with the receiving phase for the snatch and for the clean. For the jerk, might be a little bit more vertical, right? Because if we have deviation away from the vertical probably means that the center of mass is drifting forward or back, like most likely forward a little bit more so than what we would like.

And so I would just say broadly, right, the ability to learn, learning how to control that force vector dynamically during a lift like a snatch or a clean, I would say probably also has a transfer effect to being able to control forces more dynamically during other tasks. So it's not maybe as simple as saying like oh I'm vertical in this position, I'm producing force downward.

Look what happens when I lean forward and I produce force backward, right? That is a horizontal force. So it might be more nuanced than that but in the sense that it might help you better understand like how to create leverage or how to produce forces against the ground and accelerate your center of mass or to create rotation in those different situations.

James de Lacey54:24

Nice. You mentioned as well you guys do some force velocity profiling through your testing as well. You able to run through that?

Kristof Kipp54:32

Yeah. So technically more load velocity profiling. So we, again, different iterations of training camps. What we'll do is have lifters perform things like snatch pulls or clean pulls across a loading spectrum. So we might start at 70%, 80%, then work up to 110%, 120% of 1RM with our competition maximum, and that's really based off of this, we just called the German pulling protocol. There's a research group out of Germany that has done this load velocity profiling, and they've shown that if we look at the sort of slope of that load velocity profile, right, so I guess the horizontal axis is typically our load.

As we increase load, right, we go 80%, 90%, 100%, 110%, and the nice thing is that we actually go through whatever maximum performance is. So we are pretty close to, or we're getting estimates that include maximal performance. It's not just a submaximal test to predict maximal performance.

And so load on the horizontal axis, and on the vertical axis is typically things like what is your, what's the average velocity during the pull. We can connect those dots, right? And then we get a regression line and from that line we can quantify different things like, for one, what is that slope, like how steep is it, how shallow is it. And sort of what that German group has shown is that that's a very stable association between load and velocity. It can help us predict things like threshold velocity during the actual lift.

Over the course of two-year training cycles, there are changes in that load velocity profile that seem to overlay with changes in training volume. So it might be a good proxy to give us an idea of what's going on during training. And yeah, so we've used that same protocol primarily just in a cross-sectional setting with a thought that let's just do that load velocity profiling protocol.

We can establish maybe some normative data for team USA athletes and say on average the load velocity slope is X. So if there's a lifter that veers one direction, right, maybe they could benefit from doing some more pulling exercises that are more on the force side or some that are more on the speed side.

James de Lacey54:32

Is there, I'm assuming the slope is different, I assume there's a lot of factors that influence that slope, as you mentioned, like the training kind of leading into it, maybe their pulling style, I don't know, or maybe their loading style. Is there like a slope that you're kind of, I mean you mentioned obviously you're kind of trying to find it through normative data, but is there like a slope that you're looking at that would scream to you like this is something that could be hindering performance versus not?

Kristof Kipp58:06

Yeah, I don't know if it's necessarily hindering performance, but I'm trying to think about this. So we have the slope, right? From the slope, we're also able to then project out and say at a theoretical zero velocity, what would be your isometric pulling max? So it's a different way to get similar to like an isometric mid-pull or isometric pull in the start position. And there is some shared variation in that, in those tests. So we've looked at that as well. So it's a proxy for somebody's overall quote unquote strength.

Yeah, I mean we've done this with some team USA athletes and some of them, right, there are some males who are able to pull, you know, with an estimated, sort of projected max of I don't remember the exact value, but let's say like 500 or 600 kg of force. And you're like, that's a lot compared to what you're

James de Lacey59:15

What you're actually lifting in practice, right? So, or what you're lifting in competition. And so strength, pulling strength might not be the factor here. So what's the rest of the profile say? Is it a slope thing? Where are we at with the velocity?

Kristof Kipp59:30

But we can definitely rule out strength, pulling strength as a variable that we sort of need to focus on.

James de Lacey59:37

Whether that hinders your performance, I guess, is a different question, but it's certainly not hurting your performance. So are you going down the road from JB Morin and Pierre Samozino's kind of power force velocity profiling and diving deep into like that theoretical optimal profile as well?

Kristof Kipp59:54

Yeah, I mean that was the idea and I think that's where that German group adapted that profile. It's essentially the same sort of

James de Lacey1:00:02

Framework that you're, that you just described from JB Morin and Pierre Samozino. And so yeah, you could broadly break this out into sort of strength dominant or speed dominant. It's not quite as, those two categories aren't quite as clean as some of the like jumping and sprinting because it's weightlifting is a little bit more technical in that sense.

Kristof Kipp1:00:27

But that's the, I think that's the underlying framework that we use so that we have in the back of our mind when we apply that

James de Lacey1:00:35

With weightlifting being a quote unquote strength sport, would you expect people to have more of a force dominant profile then? And are you trying to potentially steer them that way? Or are you looking at that and being like, hey, you're way force dominant, we need to bring you down more to this kind of theoretical optimum profile there? What's your thought process around that with weightlifting?

Kristof Kipp1:00:35

Yeah, good question. I mean, if we're only ever testing weightlifters, right, the average of that slope or the average of our data will be the average weightlifter. So

James de Lacey1:01:09

I think it's slightly different than like in general if we look at jumpers across different sports or different experience levels. I mean the, so Ingo Sandau was one of the authors of some of this work that came from the German group. He also has a sort of extension of that theoretical model of trying to apply this then to training implications of like, do we need to, essentially just like you describe, do we need to spend more time strength training, or do we need to remediate that velocity deficit if somebody's more strength geared? Trying to optimally balance their protocol, their profile.

Because in weightlifting, right, the, I mean ultimately the goal is just to lift more weight. It's not necessarily to move the barbell faster.

Kristof Kipp1:02:02

It's not like a takeoff velocity thing as much as jumping.

James de Lacey1:02:05

Right. So there's a little bit more of a constraint on the velocity side in that if we have a specific pulling test, the threshold velocity that we're trying to predict doesn't, shouldn't really change, right? So if you have a threshold velocity, let's say for a snatch, that the minimum you need to hit is 1.7 meters per second or 1.8 meters per second, then there's no reason that we need to extend that out to 1.9 meters per second.

So if the role of, in that sort of Morin's model, right, if we want to increase power, essentially it makes sense to almost exclusively do that through increasing the strength side of things and keep the threshold velocity bit the same. Again, that's probably a little bit simplistic,

Kristof Kipp1:02:59

But that's where I think the model comparison breaks down slightly.

James de Lacey1:03:05

Yeah. No, I love this topic. I published my master's thesis paper with JB and Pierre.

Yeah, looking at power force velocity profiling as part of a taper, kind of like trying to pair together this idea of this overshoot muscle fiber type overshoot with the taper, and then see if we could see the outcomes from a power force velocity standpoint, which is pretty, and it was done in professional sport during a preseason leading into a season. So it was like a proper, I guess you could say real world setup versus kind of like an intervention. Yeah, so it's like a, I love that topic. I don't know why. It's just, it's just something so interesting to go into.

Kristof Kipp1:03:48

I mean, I'm totally there with you. We've done it with some track and field athletes here at Marquette University. We've done it with our men's basketball team. When some of that work first started coming out, right, because I think it was, it's a simple method. And like some of the things, like, or I should say, like some, what you've pressed me on a little bit is like, what are the coaching

James de Lacey1:03:59

Takeaways, right? I think is that from that model, the coaching takeaways are really clear. It's like you're strength dominant, you're speed dominant.

Kristof Kipp1:04:24

And then there was that paper that they published where is in one of the Frontiers journals, I think, where it's like based on the percentage, here's a ratio of what your exercises should be in training, right?

James de Lacey1:04:36

Was it Pedro Jimenez?

Kristof Kipp1:04:39

I think so. Should it be like a 70/30 split of speed and strength? Should it be a 60/40? And so the simplicity of that, I quite liked it as well. And that's, I think, the same thought process that we carry, that we carry with us when we try to apply it to weightlifting.

And that's what Ingo did with that. And it was a case study where they did that with some members of the German national team. Because in their system, they basically do snatch pulls, I think, every Monday or Tuesday, like early in the week it's always snatch pulls.

James de Lacey1:05:20

And so he was able to convince several of their national team members, it's like, can you just record these like every single week? Send me them. And he would analyze them and do that same sort of profiling.

Kristof Kipp1:05:33

Yeah. It's, as you mentioned, like the hard thing is how well does it translate to non-takeoff activities? Like can you apply it to, I guess, traditional weightlifting, or even traditional lifting? I guess traditional lifting is probably even harder because you have that deceleration component.

James de Lacey1:05:51

Whereas you don't have the kind of ballistic movement. But yeah, it's a cool area of research. Christof, I don't want to take too much of your time because it's already past an hour. But where can people find and follow you and keep up with what you're doing?

Kristof Kipp1:05:51

Yeah, I try to be somewhat active on social media. I have an Instagram account. That's just my name, christoff.kip. I guess I have a research gate account where you can find some of the research. Otherwise, email me.

I've been trying to think about doing some substack writing where I can share some ideas and a little bit more long form writing with analyses that, you know, that stuff gets lost on Instagram pretty easily. If I post something and I'm never quite sure how people will respond to it and then I look and see the click-through rate is pretty high and people look at it for three seconds I'm like, wait, I just wrote all this stuff. But it's like I know it's for different things.

But yeah, so that might be, that's something that I'm sort of mulling over and I think it'll be a better way to share some more like these types of conversations where it's like information a little bit more in depth.

James de Lacey1:07:05

Yeah, how we used to learn, how we used to learn through blogs and papers and talking to people versus a 30-second clip that doesn't tell you anything except for whatever is surface level and it has to have something crazy at the beginning for people to actually watch it.

Kristof Kipp1:07:19

Well, that's what I'm learning, too. And it can only be three words or something, right? If you put anything longer than that, that doesn't...

James de Lacey1:07:28

You need to do one that says something like, this is why Olivia Reeves lifts wrong or something like that.

Kristof Kipp1:07:34

Well, so I again, I have friends who are pretty active on social media and they tell me it's like, you need a better hook and it needs to be more controversial and like, are we just creating clickbait? I don't know. I struggle with that a little bit.

James de Lacey1:07:49

Yeah, it's... No, but I appreciate you coming on, Christof, and sharing everything. This was awesome.

Kristof Kipp1:07:55

Okay, I'm glad you found it useful and yeah, likewise, it was fun chatting and getting some of these ideas and thoughts out there. So, appreciate it.