View all show notes and timestamps on the KoopCast website.
Episode overview:
Diego Jaén-Carrillo PhD is a postdoctoral researcher at Universität Innsbruck. Weighted vests are a common intervention used by both coaches and athletes, yet the existing research on weighted vests is virtually nonexistent. In this episode we discuss his pioneering study on weighted vests and their potential training applications for running and hiking.
Episode highlights:
(16:41) Research design: incremental speed and gradient test, 5-10% body weight vests represent in-race loads
(21:26) Stride length and stride frequency: both increase with speed, both variables were unchanged with weighted vests, individual preferred stride frequency and stride length
(29:08) Weighted vests for running economy: example ways to train leg stiffness, weighted vests training leg stiffness with greater specificity to running, ~5% bw is reasonable, application across a range of running velocities
Additional resources:
Training Specificity in Trail Running: A Single-Arm Trial on the Influence of Weighted Vest on Power and Kinematics in Trained Trail Runners
SUBSCRIBE to Research Essentials for Ultrarunning
Buy Training Essentials for Ultrarunning on Amazon or Audible
Information on coaching-https://www.trainright.com
Koop’s Social Media
Twitter/Instagram- @jasonkoop
View all show notes and timestamps on the KoopCast website.
Episode overview:
Diego Jaén-Carrillo PhD is a postdoctoral researcher at Universität Innsbruck. Weighted vests are a common intervention used by both coaches and athletes, yet the existing research on weighted vests is virtually nonexistent. In this episode we discuss his pioneering study on weighted vests and their potential training applications for running and hiking.
Episode highlights:
(16:41) Research design: incremental speed and gradient test, 5-10% body weight vests represent in-race loads
(21:26) Stride length and stride frequency: both increase with speed, both variables were unchanged with weighted vests, individual preferred stride frequency and stride length
(29:08) Weighted vests for running economy: example ways to train leg stiffness, weighted vests training leg stiffness with greater specificity to running, ~5% bw is reasonable, application across a range of running velocities
Additional resources:
Training Specificity in Trail Running: A Single-Arm Trial on the Influence of Weighted Vest on Power and Kinematics in Trained Trail Runners
SUBSCRIBE to Research Essentials for Ultrarunning
Buy Training Essentials for Ultrarunning on Amazon or Audible
Information on coaching-https://www.trainright.com
Koop’s Social Media
Twitter/Instagram- @jasonkoop
Trail and Ultra Runners. What is going on? What's happening? Welcome to another episode of the Coupecast. As always, I am your humble host, Coach Jason Koop, and this episode of the podcast is going to be one of those that is immediately applicable to a lot of coaches and athletes out there, and that is because it has to do with a training intervention that I know a lot of you use and a training intervention that we have very little, if any, research on, despite the fact that we don't know a whole heck of a lot about it, and that is the use of weight vests in the sport of trail and ultra running. So y'all, welcome to the podcast today.
Speaker 1:Diego Hayan Carrillo out of the University of Innsbruck. He just happened to produce, with his group, one of the very first papers that looked at how weight vests actually affect biomechanics and different kinematic properties and how that is, in fact, applicable to you. I found this podcast and this conversation absolutely fascinating. I found the piece of research absolutely fascinating A link to that research will actually be in the show notes and the setup for this research was actually quite elegant. The design was actually quite elegant, where he took a group of runners and measured them without a weight vest at 5% of their body weight and at 10% of their body weight and looked at all these different biomechanical properties. Once again, I'm not going to spoil the outcome of this research, but I do think it's one where people are going to start to think about the use of weight vests a whole lot differently after they view this particular piece of research. All right, folks, with that as a backdrop, I am getting right out of the way.
Speaker 1:Here's my conversation with Diego Haiyan-Carrillo all about the use of weight vests in trail and ultrasonic. Welcome to the podcast. Appreciate you jumping on the horn with me. Interestingly enough, we're going to talk about a topic that for years, I've actually tried to find a lot of research on. You're already kind of like nodding your head because you know where I'm going to go with this question.
Speaker 1:There hasn't been a lot of exploring of this particular topic, despite the fact that using weighted vests as a training intervention is actually quite common, not just in trail running, but across a wide variety of sports. We use it in strength and power sports. They've used it in track running, but then also in trail running. So there's this discrepancy between what we see in practice and what we see a lot of athletes do and research, where there's kind of an absence of the research, I always get kind of quite curious about it and almost start to dig into the kind of biomechanical fundamentals and try to in this case the biomechanical fundamentals and really extrapolate from there. So I'm appreciative that you're doing some of the work that you're doing, but before we get into it too much, can you give the listeners a little bit of a background just on you and the lab that you work in and some of your previous work, just so they can kind of get to know you a little bit better?
Speaker 2:Yeah so, jason, first of all, thank you very much for the invite. It's a great honor to be here with you, and yeah, so where come my interest in this right? And what's my background? I studied sports science in Spain and after that, I completed my master in high performing in sport. And, yeah so, my master. The thesis of my master was about ACL injuries, but then, after that, I just took a gap in the academia yeah so, in the academic career and I was just working as a physical education teacher, not only in Spain, but also in Germany.
Speaker 2:And once I got back to Spain, it happened that I started working at the University of San Jorge in Faragosa, and something that happened to me is that I met one of the supervisors of my thesis, of my PhD thesis, and this was like love at first sight.
Speaker 2:So I found someone who was passionate about running by the mechanics, and I just knew that I wanted to do my PhD thesis with him, and if you go into my research, you're going to see many papers that we have worked together. So he's Luis Enrique Roche, and the other guy is Felipe García Pinedas. They, too, were my supervisors, and yeah, so they taught me quite a few things. Yeah, about running, about science, about life at the end, and we focused on lower limb stiffness in long distance running and we based lower limb stiffness on BrinksMask model that I assume that you are very familiarized with and, as you know, this BrinksMask model is very useful in order to describe how we behave when running right and in order to describe that you need spatio-temporal parameters and in order to calculate or estimate lower limb stiffness outside of the lab or without treadmill also implemented treadmill with force plates and so on.
Speaker 1:Really sophisticated equipment.
Speaker 2:Yeah, yeah, so not all the labs have that equipment right. And then, yeah, we wanted to do something applicable, so not only in the lab, but also outside. And then, yeah, so we went into basaltemporal parameters step frequency, contact time, flight time, udefactor, step length and lower limb stiffness so leg stiffness and vertically stiffness and it happened that I completed my PhD, then I started working as a system professor at uni I was working before, also as a lecturer, and yeah, so after five years, I got a job offer from the University of Innsbruck, when I'm working right now, and I thought that was high time for a change. But I'm still working with my group in Spain. Yeah, so I work very closely with Antonio Cartoniorente, with Alberto, with Luis, with Felipe. Yeah, I still consider that they are my group. Yeah, even though I'm joining. I joined another group here. Yeah, and I'm quite happy because I'm learning other ways of working and that was what I was looking for. And yeah, so this is my last seven, eight years, just summarized as much as I can.
Speaker 1:Well, it's always hard to summarize that length of time in just a few minutes, so I appreciate it.
Speaker 1:So we're gonna talk about a paper that this group just came out with, and the title of it is is Training, specificity and Trail Running a single arm trial of the influence of weighted vest on power and kinematics in trail runners. And these titles always tend to blur along, but basically you're putting weighted vest on trail runners and you're asking them to run at a variety of speeds and underneath a few different weighted conditions. We're gonna get into the paper proper. But first off, what's the origin of this? Right, because once again, it's not like there have been other studies here, but they're not all that prevalent within trail running specifically. So where did you guys come up with the idea that, hey, we're gonna strap weight vest on trail runners to have them run at a few different body percentage of body weight and a few different speeds and see what happens?
Speaker 2:I've been always a fan of trail running and I just started training people so training athletes and training myself as well and I heard from other coaches that they use these intervention and I started just doing some research on the literature review right.
Speaker 1:It sounds like the same thing I went through right. I saw some other coaches do this as an intervention, and then I tried to figure out why.
Speaker 2:Yeah, and I found nothing.
Speaker 1:Exactly that's exactly what I found out too. I found nothing.
Speaker 2:And if you like what they discussed, then I only discussed the results that we found with a couple of papers on sprinting.
Speaker 1:Right.
Speaker 2:Yeah, then we found nothing, nothing at all, and then I thought, yeah, so then many coaches are implementing these intervention, but they don't really know what's happened. Yeah, so we don't really know what's happened. Then we decided to do a very easy to do study. Easy to do study, so easy, an easy study with a great exercise test, with different percentages of body weight on the vest, and then let's see what happened. Yeah, so, and that was the origin actually you mentioned it's easy, but like you have to start somewhere right.
Speaker 1:That's what I always bring up when we start to evaluate research and people get into this nuance so, oh well, they should have done this condition or that condition or whatever.
Speaker 1:You have to start somewhere and since there kind of is like literally nothing at this point, this is where you chose to start and it's honestly like it usually ends up being the most reasonable and practical. Of all the different permutations of these types of studies that can actually come out, as usually the original, few of them end up having the most practical like use case values. So you mentioned that you know you were training yourself. You're also advising athletes on different types of training interventions. You're observing coaches use weighted vests as a training intervention and you wanted to kind of like really peel it apart. We're gonna like go for the jugular first and like go straight to the results and then we'll kind of like back up into that with the actual study design and specifically what came out of the study. But looking at it through a coaching application and through a training application, what are the use cases, as you see right now, of using weighted vests as a training intervention for trail and ultra runners?
Speaker 2:Yeah, so what we found was that we decided first let me do a gap yeah, but we decided to use 5% and 10% of the body weight because, after talking with athletes, coaches and so on, we saw that the most common weight that they were carrying during their races was about two kilos, three kilos, maximum four kilos, then two kilos, 0.5, one kilo. Yeah, how can we get that? Okay, we're something that we can standardize.
Speaker 1:Yeah, so you're looking at a race situation and saying a mandatory kit which is more common in Europe than it is in the United States, that's gonna cost somebody about two kilograms worth, depending upon the type of kit. So you're looking at that as kind of the original basis. Is what you're saying.
Speaker 2:Yeah, yeah, yeah, that's what I'm saying. And then trying to standardize just in order to go. One is forward. The reviewers of the paper. We thought of the standardization of the weight Because it's not the same that female athlete 45 kilos carrying five kilos, then a male athlete 70 kilos carrying out five kilos, and then that's why we decided to use patient's basis of body weight just in order to normalize the or standardize the conditions. And, yeah, if we do a spoiler of the take home message, yeah, that's what we are aiming to do right now. So if your question goes in the direction of can you give practical intervention or practical advice of how many times do you need to do this or how many times in a block can you do that, that's a question that I cannot answer.
Speaker 1:Why.
Speaker 2:Because I haven't done any intervention. Right, our study was just a descriptive study, a sectional study. Then we looked at the acute effects. But we don't know what can happen if we implement these intervention for eight weeks, for example. Let's say eight weeks. A couple of times a week, yeah, for example Tuesdays and Fridays, yeah, we do, maybe easy runs, okay, or maybe we do interval training. I cannot say that, yeah, okay, because I don't know it. Yeah, because I haven't tested it, yeah. And then I'm a coach, but I'm also a scientist and I need evidence in order to give answers. And most of the answers are just hey, this works with my athletes, okay, or with me, or with these group of athletes with these characteristics, right. But I don't know if this is going to work with another, different population yeah.
Speaker 2:So with other characteristics athletes are aiming different distances? Yeah, so I can say that yeah, because I don't know it.
Speaker 1:Right. So you're taking the very stereotypical researcher response and trying to caveat the answer as much as possible. But if you look within the study itself, there's a. One of the things that kind of comes out very quickly is there's kind of a line of demarcation, so to speak, of which you can increase the weighted vest to a certain percent and that starts to change some of the kinematic variables that you're actually looking at. And I think from a training perspective that's actually quite impactful. Yeah, we can get into the how frequently you need to introduce the intervention and over what duration you need to introduce the intervention to kind of elicit some sort of adaptation. But if you're just looking at the biomechanical parameters, which is what you're looking at, there's a very clear they're the same here and they have a difference over here. That's what I'm initially trying to bring out, and then we can go into the research design. So what is that piece of counsel essentially for the athletes that are out there?
Speaker 2:Yeah, what we found is that, at a percentage of high percent body weight we get, running kinematics is not altered. So running kinematics is stable and is very, very comparable to running without loaded vest. So, and furthermore, what we found is that these light loads so 5% of the athletes body weight simulate leg spring stiffness and power output. Yeah, you can think, yeah, power, but not many athletes were using power. I disagree, yeah, so I think many athletes train with power and even though in trial running, pace is not so important as in road runners, yeah, because of the nature itself of trial running. Yeah, so, different profiles, different inclinations, uphill, downhill, flat, again uphill, so a gradient up to where most of us lead, that working instead of running. Then it makes sense that we need to aim at stimulating all the parameters that the patient, of course it's worth also working on.
Speaker 1:Yeah.
Speaker 2:I'm not saying that the patient is.
Speaker 1:Right, right, right, right, right. Okay, let's hold, let's pause really quick, because I think this is getting a little bit scattered. Let's walk through the research design that you deployed and then we can come back to this ultimate answer after we've narrowed it down. You took a group of runners, you applied a different percentage of body weight 0%, 5% and then 10% of body weight with a weighted vest and tested their kinematic variables over a range of speeds. Why don't you walk through the listeners, through just that specific design, and then why you chose the speeds that you chose and why you chose the weighted vest options that you chose?
Speaker 2:The speed that we chose were based on the speeds that are more commonly used in long-distance running. So in ultra-distance, for example, we know that trial runners were running 7.4 km per hour and so on. Then we started at 8 km per hour. That means that most all of them in our case with the participants that we had, all of them needed to run at that speed Right Then. That was a very easy light intensity of running. Then we go to 10, we go to 12, and to 14. Then those velocities, those speeds are speed that are commonly seen in inclination, so in different gradients in elevation gain. Then with all our participants, we did a great decasarstite test. So we started at 8 km per hour until volicinal exhaustion.
Speaker 2:We wanted to focus on those speeds at the end of the protocol because when we were collecting data we were also collecting the answers or the feedback from the participants, according to the patient strategies. That's why at the end we decided to go for those speeds With three different conditions in body weight, just following all the information that we got about weight, the vest that they used during races what's the weight that those racing vest are? We were just asking around, asking athletes, not only recreational athletes that we had in our study, but also elite athletes. At the end, we saw that these range of percentages of body weight would be very close to the weight that most athletes carry during their competitions.
Speaker 1:I'm going to add a little bit of context here. 15 subjects, all males. You're measuring the kinematic variables with the stride power meter, which a lot of people are familiar with. It's just a little pod that gets attached to the foot but validated in terms of the variables that you're actually measuring across. You mentioned earlier that this is a device that we're seeing more and more in the running world. Not quite as applicable from a trail running perspective, because the surface of the trail obscures a lot of the values that you're getting. But if you're running on flat level surface, that doesn't really change in terms of its stiffness. It's a reasonable proxy for a lot of the traditionally captured kinematic variables that would take much more sophisticated equipment to actually procure.
Speaker 1:You had those 15 individuals go through a standard graded exercise test to get a baseline on their current capacity. They then went through the testing protocol, which consisted of either running with no weighted vest, a weighted vest at 5% of their body weight and a weighted vest at 10% of their body weight in a randomized format, which is really important because of the learning part of it. I thought that was a good study design. Within each one of those conditions they ran at 8 kilometers an hour, 10 kilometers an hour, 12 kilometers an hour and 14 kilometers an hour. What was the period of time again? Was the standard for five minutes or something?
Speaker 2:like that.
Speaker 1:One minute, one minute, so one minute for each of those, and then you're capturing the kinematic variables across each one of those and then comparing all of the different conditions. Okay, perfect.
Speaker 2:So now that we've got the generalized study design.
Speaker 1:Let's go into the meat of it, which we're there in any differences in any of the kinematics or any of the biomechanics. So let's first take, like, within the speed conditions of any one of those trials. So we know that as speed increases, stride length and stride frequency both increase to different proportions. But do you see that actually differently across the different weight conditions as well? And is that stride length and stride frequency increased different across those conditions?
Speaker 2:Interestingly enough, stride length was stable during all the conditions, and the step frequency as well. Why step frequency? Step frequency is very run-dependent, okay, so we all run with a very, very, very close step frequency to the optimal frequency for all of us. If we run at 170 steps per minute, for example, probably our optimal step frequency in order to have best running economy going to be 172, 178, so it's going to be very close to that preferred step frequency that we have naturally. Yeah, so, and it's the same with the stride length. Stride length is very dependent on architecture yeah, of bound architecture, masses architecture, so it's very difficult to change that. So just when that's the reason when I see on social networks that you need to give longer steps, you need to run on your forefoot or you need to do this in order to get a better technique.
Speaker 1:So please don't do that, okay so amongst the weighted conditions, though, stride length and stride frequency was remarkably stable. Right, we can compare a 10% body weight condition at the same speed to zero body weight condition, and stride length and stride frequency were actually quite stable, which kind of makes sense, right? Because that's the fundamental equation, right, velocity equals stride length times, stride frequency. So we wouldn't expect that to change. So what did change? Because everybody knows that when they put on their race pack, or maybe not even a weighted vest right, their mandatory kit or their kit that they're using for a big, like you know, backcountry expedition day, they know that they feel different running around. And if you're telling them that stride length and stride frequency doesn't change, they're going to, they're going to, you know, call BS on that, because they can feel something actually change. So what are, what are the differences?
Speaker 2:Yeah, so the differences that we found, for example, between no external body weight or no loaded condition and 10% condition for a 10% body weight condition, for example, is that we found significant changes in flight time, so that is the time that we spend on the air while running Okay, and we also found a significant increase in ground contact time, so the time that we spend on the ground while running and, of course, duty factor. Why we found significant changes in duty factor? Because the duty factor is the ratio of contact time divided by two times contact time plus flight time. Then that's easy. If we found significant differences in flight time and in ground contact time, we are going to find significant differences in duty factor because it's duty factors are related to parameter.
Speaker 2:And if we look at the 5% body weight condition here, what we found was very interesting because we didn't find any significant changes in any of the running parameters that are now changing ground contact time, flight time, whatever, Okay, but as I mentioned before, we found significant changes in leg spring stiffness.
Speaker 2:So increase leg stiffness and it seems that these 5% additional body weight is an appropriate strategy to simulate leg spring stiffness.
Speaker 2:That, if you don't know, or if people are going to listen to us don't know, leg spring stiffness is one of the main muscle mechanisms in order to regulate, or in order to regulate the elastic energy we use when running. So when we do the initial contact while running, we absorb energy during the mid stance and then we release part of that energy when propulsion the body into the air again in order to keep running. So if we are able to stimulate leg spring stiffness, so probably, not probably but if we stimulate leg stiffness, we are going to be, or our running economy is going to be, slightly optimized. And we also found increasing power. So this is crystal clear because if we have more weight on us, we are going to generate more power at the same speed, at 8, 10, 12, and 14 kilometers per hour. That's clear. But we also found that at the 10 percent body weight condition, more power, but significant decrease in ground contact time. That is directly related to running performance. If we find those geoparticides sites or those handicaps, we are indeed impairing running performance Right.
Speaker 1:So when I look at this from a coaching lens, it almost seems like the right dose if you're going to use an assisted weighted vest has a U-shape curve to it to where, once you exceed the top of that U or N, depending upon how your X-axis is actually oriented To, once you exceed that external load, the use of that training intervention becomes a net negative as opposed to a net positive. And this is a dose response curve that is quite common in a lot of biomechanical and physiological properties, where you can apply a load to a certain extent and you can apply additional load to a certain extent and it ends up being a net positive. But after that certain extent, especially within biomechanics, it tends to change so much that it's not worth it. And interestingly enough, you're probably unaware of this, but we have a few of our coaches with a kind of a robust strength training background in, like team sports and things like that.
Speaker 1:And they all went through this phenomenon maybe a decade ago where all of the implements that all of the sports used so baseball bat, lacrosse stick, golf club and things like that they wanted to overweight the implement right and use it in a training session in order to kind of induce more resistance.
Speaker 1:What they ended up finding was is that in many of those applications, if they increased the resistance or the additional weight of that implement too much, it messed up the biomechanics and had a net negative effect with the athlete. We're kind of seeing this same phenomenon with weighted vest, where you can increase it to a certain extent and it affects the biomechanics. It affects the biomechanics to an extent to where the training piece of it or the functional outcome piece of it it's almost like a different sport or a different movement pattern that you're reinforcing. That then could have a net negative. Am I reading through the lines on this? At least initial piece of research on that piece is that there's probably a correct dose response relationship to how much external weight you can apply and there is probably a net negative to applying too much of it.
Speaker 2:Yeah, that's very interesting because we actually found that at dose response, right. So we found that if we increase the load until 5%, we are going to stimulate some parameters right, or some mechanisms that are traditionally trained in a different way. So, for example, let's speak about leg stiffness, right. Leg stiffness we know that if we do heavy lift things or jump in rope, so we stimulate a certain cycle in a very short time. Yeah, we are going to stimulate leg stiffness, right. But is that applicable to running? Yeah, it is, but it's that way of training, close to the natural movement, that our athletes are going to perform during a competition. No, it's not.
Speaker 1:Right, we're not jumping rope for competition is what you're saying. It's an adjunctive exercise versus a primary exercise, I guess.
Speaker 2:I use jumping rope with my athletes, okay, and heavy lift, of course, because we need to stimulate the hell of the tendons and the cross-sectional area and so on and all the adaptations that you get with heavy lift things. And we jump in rope, yeah, so arch stiffness is stimulated and leg stiffness and so on, but at the end of the day, this is not the way that runners run, right? And then we found a very applicable way to train, aiming at increasing or optimizing leg spring stiffness in our runners, right? So, and this is what we aim every single time that we carry out our research and study. So is it applicable, yes, or just another piece of paper?
Speaker 1:Well, let me phrase it a different way, right? So if you wanted to improve leg spring stiffness for an athlete, if you think that that is a and I would agree with this if you think that that's a variable that you deliberately want to improve and you want to improve it across the and make it as specific as possible to a trail runner, you would load them up with three to five or 6% of their body weight in order to do that. So that's a reasonable, that's kind of a reasonable application. If you did much more than that, you're probably not accomplishing that goal of improving and probably in your according to your research at least, you're doing the athlete a disservice and not targeting that specific piece of their biomechanical physiology right In terms of improving leg spring stiffness, because all of these training interventions should have, and whether we talk about interval design and recovery length and interval length and the length of a session and all this other stuff, it needs to be targeted at something very specific that the ends need to, the means need to need to justify the ends, so to speak.
Speaker 1:And in this case, if you're thinking about something very specific, we want to keep the running biomechanics the same and improve leg spring stiffness and potentially improve running economy through that. If you think that that's a valid variable to improve, this is a good framework. Using a few to 5% of your body weight in order to do that, because it seems to be kind of in the sweet spot of additional load that doesn't compromise the rest of the biomechanics.
Speaker 2:Yeah, yeah. So from my point of view, when we found that it was of the effort you know, it was yes, we have found something that we had. No clue, yeah, or at least.
Speaker 1:Yeah, you don't know what the dose is right. You don't know what the right dose is. Is it 5%? Is it 10%? Is it no percent? Like you don't know what the right dose is. And now, we're starting to narrow it down If you want to give it a little bit of a range. Yeah, three to six percent or something like that is completely reasonable.
Speaker 2:Yeah, and interestingly enough, we saw that like bring stiffness, increase at all the velocities, okay, and increase more. It was higher for all the velocities, always at 5% of body weight. Yeah, yeah, so that's very interesting, and for me the first one, wow.
Speaker 1:I like it and it's applicable across a range of velocities, I think is the way to think about that. Okay, so before everybody goes out and buys a weight vest that's 5% of their body weight to do all their training on, let's kind of add some caveats to this a little bit so you can put your coaching hat on and your training hat on and kind of get out of the research a little bit, because it does seem like a Goldilocks situation to where you can train with this amount, you get a little bit of an extra resistance.
Speaker 1:Maybe it slows you down a little bit more, which is a common training problem that we have in trial and ultra running, as we tend to just train too fast over the entirety of the training spectrum. But what other points of like caution or clarification do you think you need to kind of like put on this initial piece of research, since it is new and novel and it's just kind of come out?
Speaker 2:Yeah, so from a coaching perspective, I wouldn't go straight away to 5%, right? Yeah, so please don't do it. We all know that small changes are sustainable in time. Yeah, so then if our athletes are used to train with no load, maybe just put 1%, 2% and so gradually. This follows the coaching perspective and the coaching reasoning.
Speaker 2:Progressive over the way yeah so don't go straight away for a new thing, so just get it into your training routine gradually, yeah, so if you want to start using low-dip running, then start gradually and I would advise not going over 5%, because we already know and this is likely enough, yeah, we already know that if we go over, then we are going to jeopardize running kinematics and, along with running kinematics, running efficiency and running performance. Perfect.
Speaker 1:OK, so now let's extrapolate a little bit more, and this is outside the scope of this particular piece of research. But if we're kind of coming at this from the more of the original orientation of how you came at this piece of research, from which is I observed these coaches and athletes in the field using this as a training intervention, let's actually test that training intervention and see if it's valid and see under what conditions it would actually be more appropriate. And I think you've got a reasonable answer to that 5% of body weight across these ranges of speech, so speeds can be remarkably effective and 10% of body weight is probably not effective or inappropriate. Right, I think both of those flavors of answers are really important because as ultra runners, we tend to think more is always better.
Speaker 1:And there's definitely too much in terms of external load, but let's kind of extrapolate this into all of trail and ultra running.
Speaker 1:There are also a lot of trail and ultra runners and ultra running coaches that I know of that will use weighted vests to induce a hiking modality Whenever you know they wouldn't normally run.
Speaker 1:So I mentioned earlier that one of the problems we consistently have in working and training athletes, particularly for the longer ultra distance events, is their training speed is always so much faster than their race speed and that can produce a little bit of a biomechanical mismatch come race day. In addition to that, they end up spending a lot more time running during training proportionally than they are during the race. There's a significant portion of hiking and walking in races. That in particular in North America, where our trails aren't nearly as hard as they are over in Europe, athletes just end up kind of running too much, and so a way that a lot of athletes and coaches get around that is to put on a weighted vest and go and hike around, and usually that weighted vest is actually quite heavy. So I'm wondering if you could kind of like read through the tea leaves a little bit. Maybe take your research hat off for a second.
Speaker 1:Yeah read through the tea leaves and provide some commentary, based on this initial piece of research and also what you know about biomechanics, towards that specific piece as well, because I know a lot of people are going to have questions on that specifically.
Speaker 2:Yeah, so we know that the longer the distances, the longer the time are. Runners or ultra runners work Right. And we also know that, as a particular inclination, male and female athletes start working and then again and vice versa.
Speaker 1:Yeah, so they also start running at a particular inclination, they're going to start walking and then vice versa, like once that inclination comes down, they're going to start running again. Yeah.
Speaker 2:Yeah, yeah, yeah, yeah, that's it. And so, yeah, that's a very good question indeed. The thing is that we, as you mentioned before, we tend to or at least tend to think the more the better, right, yeah, right. And this can be extrapolated to the 10,000 hours of practice, right, yeah. So not the more the better, so it's the best the better, yeah, yeah. So what do I mean? What I mean is that you need to do things for a purpose. Yeah, and this is not only for running, this is for your whole life.
Speaker 1:Right yeah.
Speaker 2:So if you run every single day 60 kilometers, what are you going to get An injury? That's clear, Right? If you don't train hiking, what is going to happen to you when you start hiking? You are not adapted.
Speaker 1:Yeah.
Speaker 2:Right, then interestingly enough, you're going to be less efficient working than running, but there is a point where you cannot run, yeah.
Speaker 2:The hiking is as important as running for an ultra distance athlete, right, and I think you agree, right. And so, when we prepare our running or our training routines for athletes, we need to take all the things into account, yeah, and we need also to take or to consider not only the next race but the next race to come on the other and the other. And what are the aims of our athletes with those races? Is it an A goal? Is it a B? Is it a C race? What is it for athletes? At the end of the day, athletes need to be happy, right, because if not, we are not doing our job, right?
Speaker 1:OK, but hold on, hold on. As much as I appreciate the global perspective here and I take that as a coach right, we've always got to have athletes best interest in mind and we need to look at big long time frames and things like that. At the end of the day, I'm trying to make this a little bit more pragmatic, but the coaches and the athletes that are listening, and one of the big pieces of pragmatism that we constantly discuss and debate about is should we actually use weighted vests to hike? Right, you've kind of answered it within the running context. Right, we can run it a kilometer an hour, 10 kilometers an hour, within this range of body weight, and it's similar here and different here, and I think that that provides a good framework.
Speaker 2:Yeah.
Speaker 1:What I'm trying to really drill down into and pin you down on is is there a similar framework that you can at least theorize when you're going in a hiking or a walking modality, meaning this U shaped curve or N shaped curve, depending upon your X or Y axis orientation? Where would you theorize that that would be at least similar in a walking modality, or it doesn't matter. We can load people up with as much weight as possible, put a big rucksack on them 40 kilograms kind of whatever it is and they can kind of go out to their hearts content. I just want some a little bit of color commentary on that, since you know the space very well.
Speaker 2:Yeah, I would say so. Yeah, I would say so because what we try to do is to reflect what our athletes are going to face during competition. Right, and they are going to walk, they are going to run, so is it advisable to use weighted vest while hiking as much as while running? I think so. Yeah, I think we can. We can take that from a coach perspective. And taking my researcher head off Okay, also hot off, sorry.
Speaker 1:Yeah, and then what else can you say about the load? Essentially because one of the things that your paper very elegantly did on the running side was kind of figure out what the appropriate load was. Is there any learning lessons with that? And that would be applicable on a hiking perspective as well. Like, is there a load that's too much? Is there a load that's too light? Would there likely be a sweet spot? And because once again people are gonna go out and say how much, if I wanna use this hiking versus running, how much weight should I put in it? And I know that it's hard to provide exact answers, but can we at least get some framework for it?
Speaker 2:I think I would stick to the conditions that athletes are going to face during the competition. So if athletes are going to carry four kilos in the vest, let's use four kilos. It doesn't make sense if you use eight, why? What's the point?
Speaker 1:Yeah, yeah, I mean, and that's what I'm trying to get at is more from your practical point of view I know we don't have the research on this when are the parameters? Would be, because certainly there's some contingent of athletes and coaches out there that'll your four kilogram example will go five or 10, x of that, 20 kilograms or 40 kilograms, and include that as a deliberate, as a kind of a deliberate mode or deliberate training intervention to either induce hiking or to just add additional resistance to hiking. And I've always looked at that as something, at least personally, I've always looked at something that is something that kind of defies the law of specificity you mentioned it's not something that an athlete is going to contend with on race day.
Speaker 1:They're not going to have it, in most cases a 20 kilogram or 40 kilogram pack on. So why would you do it in training? But I was wondering from your perspective, from a biomechanical perspective, does that still defy that law of specificity or would there be a use case for it?
Speaker 2:Well, I can say that you just gave me an idea for a new study there, you go.
Speaker 1:I thought we could give people a sign up for it. Yeah, please do that. By the way, I'll bring it back on, and after you do that study, so please do it. Once you do it, we'll bring it back on and we'll talk about that one.
Speaker 2:Yeah, yeah, yeah, I'll try If you design that study.
Speaker 1:What would you think, though? What would you think would happen?
Speaker 2:I don't know. I don't know because we were analyzing gate yeah, instead of walking gate, instead of running gate, and there are some differences, okay, and we humans are extremely stand by walking more than while running, yeah, and then I don't know. I just feel I don't have an hypothesis right now, sorry All right, we're gonna work on that way.
Speaker 1:You give back to you.
Speaker 2:Yeah, and I don't really know. It's interesting and I think I'll do it. At least I'll try my best to do that study and that way I can come back.
Speaker 1:Okay, well, we'll leave your contact information to the show notes and whenever you need a subject pool, I'm sure we can help you find one, because once again, like I said, I've appreciated this from a running perspective. It's an intervention that I have personally seen a lot. I see it and we see it in the US a little bit more commonly in a walking modality. So I wanted to kind of know if we could read between the lines a little bit and take any learning lessons from this into the walking sphere. I didn't get the question. What's the question? Oh, there wasn't a question there, it was just more of a statement.
Speaker 2:Ah, just a comment, right, yeah, it's all good, all good.
Speaker 1:Okay, perfect, Ben Well, this has been fascinating. I really appreciated this conversation and I appreciated this piece of work when I originally saw it, because I think it's something that's directly applicable to a lot of people that are using this type of training intervention. Where can people get to know you a little bit better and find more out about the research that you do and follow you on any of your social handles?
Speaker 2:Yeah, so if they want to follow me on, they can find me on Instagram and in X from my Twitter they type at d-a-d-j-i-e-n-d. Also, my name is Diero Chain. Yeah, and there I said it would be at d-j-a-e-n-d.
Speaker 1:And I'll leave a link to that in the show notes.
Speaker 2:Yeah, if they need to contact me, I'm always open for discussion and I'm always happy to answer questions and hear new ideas, perspectives. So if you need to contact me, please feel free to do it.
Speaker 1:Well, I appreciate it, diego. I'll leave links to that, as well as links to the paper, in the show notes. It is a free, open access paper, so anybody can dive in and read it and keep up the good work over there, man. I can't wait to see the hiking study that's gonna come out in a couple of years, apparently.
Speaker 2:Yeah, jason, so thank you very much for putting in the invite again, I really enjoy the conversation and, of course, you gave me new ideas, so thank you very much and I really appreciate your time. Awesome, appreciate it. All right, folks. There you have it. There you go.
Speaker 1:Much thanks to Diego for first-top producing this piece of research. That is sorely needed, and I hope that we've inspired him to do a follow-up piece of research where we look at a weight vest intervention in a hiking modality. Links will be in the show notes to everything that we talked about, as well as all of the social media, and I hope that you'll be able to see them in the next video. So that's everything that we talked about, as well as all of the social handles that Diego has. I encourage you guys to go and check it out.
Speaker 1:If you found this podcast fascinating, go ahead and check out my new research newsletter, research Essentials for Ultrarunning. This is going to be a paper that we review in depth and we put in a future edition of that particular e-magazine, because I think it is one that is so incredibly relevant to trail and ultrarunners nowadays. It's a training intervention that I see used all too often and, as I said during the intro of this podcast, it's one that we really don't know a whole heck of a lot about in terms of how much weight to put on, what speeds are relevant and what is actually going on underneath the hood when we use these types of interventions. Link will be in the show notes to sign up for that particular newsletter, and I would expect it to come out in maybe the December or the January edition if we have all of our stuff together.
Speaker 1:I appreciate the heck out of each and every one of you listeners out there. If you like this podcast, please share it with your friends and your training partners. If you think the information contained in this podcast is valuable to them, go ahead and share it with them. That is the best way to spread the love and to spread the info, and I'm so incredibly grateful for whenever I hear this podcast going to get proliferated across the space of trail and ultramarathon runners and coaches. That is it for today, folks, and as always, we will see you out on the trails.