Evidence Strong
How to pull for great snatch and clean - with Tavor Ben-Zeev
So it's different, the pattern is also different. Female athletes had the highest correlation and much higher correlation from their style position. So that was something that was very interesting for us. So that was the result physically for peak force number, either meant to peak force. Could you explain why you think you found the difference? It's interesting because it's only my opinion. So it's not something that we really measure it. But I think also the female athletes are much more technique driven. So a lot of female athletes, an anecdotal observation for my both of the female athletes, much more really driven by their anxiety, perfect their technique. So they will really try to maintain the right position for the entire world. Hi Davor, it's my pleasure to have you here at Evidence Strong Show. If you could briefly introduce yourself, that would be awesome. Hi Alex Sefrist, I'm very excited and very honored with this conversation. And I just want to say thank you for everybody's platform. The evidence strong is really great. I'm using it as a way to coach, as an end scientist. So yeah, I am currently a PhD student to a side to geology and sports science program in a Yale University in Israel. And my PhD is divided into working on sports performance with athletes, trying to make them better from under a faster and also understanding the strategy behind training and animal experiments. I'm also a way to coach, friend coach, and I'm the transient condition controller for the Israel-made ethic. Most sounds super impressive. I invited you, because you have out of the paper, titled comparison of force measures between start position, transition phase, and mid-type pool with weightlifting performance during Israeli national competition. So we will be talking measuring performance in weightlifting or trying to guess it. And you're under this amazing study. So let's hear more about it and let's start with the why. So what was the aim of the study and why it was needed? Yes, so the aim of week started from understanding that there is kind of a gap in scientific literature. With most of the study, then make this type of topic, which is correlation between i-vometric force and weight performance. Mostly focus on the i-vometric meat cycle, which represents full position and the start of the second pool. But if we look at weightlifting movement, especially the pool, it's divided into three phases. We have the first pool, the transition phase, and the second pool. So right now, we can understand that there is a gap. But now we have very strong understanding on the population. From the mid-type pool, we will keep weightlifting performance. And it's very good correlation. It's about 0.75, 0.85, which is very strong, but it's not perfect. And we don't see the whole picture regarding the pooling movement. There is one study by Joffee and colleagues. And they were the first one to measure in the start position, the i-vometric pig force from the start position. And they got very, very much stronger correlation. Deval correlation was 0.95. Compared to what they found, the i-vometric meat cycle, which was 0.885. So right now, there is a big difference between one position to another. Our study also wanted to take a look on the transition phase. They had for our study, none of the scientific research really addressed. And the aim was to get a much more linguistic view on the pool movement to make us better understand weightlifting performance. And also, maybe we can get much more better monitoring tool to predict the fart. Okay, so this is how you went to the study, and now how you went about answering the question, is it possible? So all of them measure what's conducted on a first plate. So the athletes needed to stand on first plate. Then we took a far better pattern on mobile, which means if the athletes want to move, they cannot. That's how we measure i-vometric pig force. So the start position, the barrel was located top position, which we can measure with because the diameter of the weight, the weight of the weight is the same. Measuring the transition position, the barrel was located just below the knee at the center. And the i-vometric mid-side pool was located at the power position, which is the point of the contact, the contact, the barrel contact with the body. Those were the three positions that we analyzed. We measured, all of our measurement was on attack one week before and one week after the Israel nationals. And all of the participants had to be qualified for that competition, which means they had a certain and simple number to compete. And we had 30 participants, 18 from them were male and well were female. Also, okay, so we know what you have done, where you invited, so you tested a week before and a week after. So you did these measurements on i-vometric pools in three positions. And then you put it against the weight-lifting performance. Did you use total or some class? No, we used this total. We want to see exactly their weight-lifting performance. And their performance was measured at the Israel nationals. Because we want to really grasp their real and highest performance, which you all want to be in their competition. And Israel nationals, it's the highest competition in Israel. So that we're moved that will prepare their best. So yeah, we measured their snatch, clean and durable. And that's, and we collaborated, of course, indeed the correlation to three positions that we mentioned before. All right, to the result, what have you found? Okay, so let's begin. Our hypothesis was that we will find a much greater correlation from between the start position and the transition when we repair it, the i-vometric mid-fi pool. And that's really what we found. We found that the correlation between the i-vometric start position and the i-vometric revision phase was significantly higher than the one from the mid-fi pool. It was, I would just look at the number. So it was 0.95 and again 0.95 for the i-vometric start position and the transition position. And from the i-vometric mid-fi pool, it was 0.86. That was when we analyzed all of the participants. So right now you can see there is quite differences, large differences. So that was kind of reassuring our hypothesis. After that, we want to analyze and see what's the differences of the participants by gender. We want to look at the male and female separately. And what we saw that in the male participants, the result was very similar. The number was 0.91 and 0.91 again from the art position and position. And it was 0.81 for the i-vometric mid-fi pool. So it was very similar. The number are similar and the pattern is similar. Like we saw combined participants, when we looked at the female athlete, what's kind of the female group. The correlation between the style position one was 0.94. The correlation from between the transition phase was 0.79 and the i-vometric mid-fi pool was 0.69. So it's different. The pattern is also different. Female athlete has the highest correlation and much higher correlation from their style position. So that was something that was very interesting for us. Because we didn't participate in it. So that was the result physically for peak force number, i-vometric peak force. Could you explain why you think you found the difference? And that's interesting. Peak force, did you say? Yeah, so it's interesting because it's only my opinion. So it's not something that we really measure it. But I think also the female athletes are much more technique driven. So a lot of female athletes, an anecdotal observation for my both of the female athletes, much more really driven by their anxiety, perfect technique. So they will really try to maintain the right position for the entire pool. And compared to the male, that someone, someone much more aggressive and they tend to focus more on the external results and choose the way it, rather than the peak. So sometimes female athletes will deliberately slowly think, will slow down their pool and compare it to the male athletes that will pull much more aggressively. I also think that we know that female athletes are weaker in terms of pure strength than the male. So maybe their style position is much more limiting factor to their overall performance. So we didn't want to just measure peak force. We also, as the weightlifting coaches and scientists, to understand that speed is very important factor in weight performance. The ability to use force in higher rates. We also analyzed the rate of oil development at 250 milliseconds. And what we found, it was also very easy to ask when we measure all of the participants. We found that the only position that we found at significant correlation was the style position, which is kind of different than the overall literature. Because we used previous studies mentioning that the rate of oil development will be correlated with performance at the isometric mid-type pool. And also, I believe a coaches will a lot of times say that the second pool is deposition that we need to accelerate the barrel. But we found that rated force development was correlated only in the style position. Now, when we separate this event, we found something even more interesting. Because in the male, there was none significant correlation at any of that position. So we didn't found any significant correlation in rate force development and weightlifting forms. When we looked at this female athletes, we saw similar results to the like the total participants. And we found again that the only position that was correlated significantly with weightlifting performance was the isometric style position. And it wasn't a strong correlation. It was moderate, and the number was 0.67, which is not perfect correlation. It's not very strong, but it is a significant correlation. And it's interesting because only in the female, we found that correlation. We didn't found a group. And I think it's somewhat going against a certain belief that maybe the first pool should be deliberately slower than the other faces. And I don't think it's the right approach that we can coach the first pool. And from our study, we can see that producing a lot of force in a higher rate from the start is correlated with weightlifting performance. Why do you think the correlation was present at first pool, but was not at the power position, even though the previous research had suggested that that should be the case? Great question. I think first, I think that people need to understand that the first pool, it's much more of a strength-oriented position of the athletes' needs to overcome the power of the inertia. Powerable is starting to see what we lost in. The transition position is much more technical. It sails because the athletes need to re-adjust their reposition to be able to locate them at much more favorable position to produce force vertically. And the power position, if we look at it just like not regarding the other position, just the power position. So yeah, it's much more speed and speed fixed because the velocity that the power will get from the power position is the velocity that will determine the power of height, like quantum moving jump. But if we think about it, it's again the power position. Second pool is the snaps. When you perform the either metric with a pool, you are in the perfect position. You are in the perfect position. You're both of your feats. The whole foot is on the ground. Your torso is vertically. But we know that if we take a video of a lifter, most of them will not be able to execute that type of power position because their previous position will determine how well they will execute the power position. So I believe when you're analyzing athletes, maybe they are not the elite of the elite, the first pool will be much more better indicator of their performance than the other than the either metric in the power position. So what was interesting is that I thought maybe the position plate will give us also the positive correlation. We didn't find it, but there is previous study that also indicate that a weak level athlete can generate high level forces and velocity from the start. So, specifically, I don't know why previous study that naturally be found in positive correlation for a rate of full development or from the either metric need by pool. But we have previously studied showing that high level elite level lifters can produce higher velocity from the start. So producing high high velocity from the start is some of the good thing that we wanted. The problem is that a lot of athletes will, when they will strike to it, they will, their position will be great. So they won't be able to maintain the proper position. So it's kind of a ball. You need to pull the barbell fast as you can, but also maintain maintaining the proper position that we know from the technique month. All right. So now let's move to the practical application of the study. What coaches can take out of the study and how to apply it in the coaching practice? Yeah. So first, it's very important to address that correlation is not equal causation. We measure isometric force. We didn't measure dynamic force. This is very important to address, but I believe our results can indicate some very important occasion. The first application is very easy. Coaches that have access to horse plate can monitor in a very successful and very high for the capability, they're weight if they're performing. So if you have a foresight, you can locate or play at out position or the tradition position. And with a very accuracy, you can predict your athlete performance instead of just maxing, passing out the stature and the clean and jerk, and we know maxing out weight, you think before, a weight listening derivative. Sorry, it's very taxing on the body. But that's very useful way to their performance. Another thing that I believe is very important is that we found that athletes that can generate higher level or from the ground, from the start position are having higher performance. So I believe we can coach our athletes to be strong. We need to coach them to be stronger from the start. That means we made it program higher, higher percentage in the pooling movement, not just like the traditional 100, 110% from your 1D RAM. I believe we can't push them a little bit forward to work with higher percentages from the pooling exercise or in derivatives. That's one thing that I believe is very important. Second one is that I believe we need to program much more variation, addressing the position and faith at the technique position, which means we need to force our athletes to understand how the weight of their knee can be with derivatives that force them to move the barbell rapidly low and above the knee. It can be like something like floating snatch or cleans, but a lot of variation, I believe the transition faith is very important to the adults to understand the how to properly execute it. And I, after we finished our study, I changed a little bit to my programming style. I put much more variation in addressing the position face at the technique position and also I changed also higher program pools. I now am working, I program higher loads and I can also vary a program, a lot of variation that we force the athletes to understand the right position at the start position and also at the transition position. Would you have any comments how to distinguish between programming for female and male athletes? Because the results were slightly different from your study, how would you now apply it to the coaching practice? Yeah, so first again, like I mentioned before, if you have an access to a force plate, I believe that the only real and a good way to predict their performance with the fourth plate is with the start position, because we saw the correlation from the transition position at Andy, the either met with me, that was much less than the start position. That I also think that we can coach female athletes to pull the barbell with higher velocity from the start. I think we can see that maybe female athletes will pull deliberately slower, so we are coaching them to generate higher rate of force development from the start and to start at the first pool more rapidly. It will is a better approach to the overall performance. I think it's specifically to the female athlete, because like I said before, males tend to be more aggressive. I have one more question, so this is the question coming from a young coach who asked me for help in assessment of our athletes, and she wanted to know what is the relationship between the pools and the grip strength and trying to correlate it to performance. Do you have any thoughts on that? Yeah, I believe that a grip strength is not a limiting factor to weight addition performance and as specific to the pool. I think when you are training with the weight lifting derivatives, your grip will be strong enough. I can see some someone that have maybe weak grip, that very individualization approach to a specific person, and for that person, I will say first thing may be limiting their use of traps, so if someone has a weak grip and they are using traps all the time, so I will limiting the use of traps, especially in pools. So most of the athletes will use traps in the pooling derivatives, so if I have an athlete weak grip, I will tell them like I will limit their use of traps in the pooling derivatives, so you will feel the heavy barbells on the pooling derivatives. It may be, and also it can help with confidence. I use the confident booster, which means if I have an athlete that may be lack confident and he is working with the pools of the puppies in one rim, I will want him to work without a feel the barbell, feel the specific weight of the barbell to get more confident with that specific weight, if it's answered the question. Yeah, do you measure at all grip strength with your athlete? No. I mean, I measure it sometimes for readiness because there is, I mean, to see the fluctuation in readiness, but I'm not putting a lot of emphasis on it. I don't believe it's a strong indicator of performance, of performance, specifically weight strength. Do you use any jumping as a measurement of readiness or full-backing? Yeah, yeah, I will use the counter movement jump without the use of the hands, to see to predict readiness. Also, we did a pilot study on the correlation between counter movement jump, drop jump with the jerk, and we did see a sample and moderate correlation. So, I also will use it. I will use both jump height rather than peak force. If I'm measuring counter movement jump or any other jump derivatives, I'd rather to use the jump height. I believe the jump height is a better indicator than the peak force, but also it can be a little bit harder to coach because athletes can cheat on their jumps, they can use a greater counter movement, they can kind of use their hand. I mean, when you have a standardized approach to the counter movement jump, I think it can be very, very useful for both readiness and to predict jerk performance, not as much to the stature and the clea. Awesome, that's very interesting. Thank you. Bigger, a favorite color. Right. That was quick. Keep people want to contact you and ask some questions or just get in touch. Where should they look for you? Yeah, so first they can find me on Instagram. It said that the word would be a WBL and also on a research gate. So, if people want to get access to this research paper, please send me a message on research gate and I will be more than happy to share this paper with you. I mean, it was kind of my dream to publish a paper and induct a paper on weightlifting from like my undergrad degree. So, I'm very, I'm very happy and excited for this paper. So, for me to help coaches and this paper can help coaches to be better coaches and make better athletes amazing for me. So, yeah, just send me a message and I will send it right for you. Thank you so much for the work for today. We learned a lot and thank you for your research. Thank you, Alex. Thank you very much. [BLANK_AUDIO]