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Expand your running knowledge, identify running misconceptions and become a faster, healthier, SMARTER runner. Let Brodie Sharpe become your new running guide as he teaches you powerful injury insights from his many years as a physiotherapist while also interviewing the best running gurus in the world. This is ideal for injured runners & runners looking for injury prevention and elevated performance. So, take full advantage by starting at season 1 where Brodie teaches you THE TOP PRINCIPLES TO OVERCOME ANY RUNNING INJURY and letβs begin your run smarter journey.
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On today's episode, we are diving into the latest running research on super shoes. Welcome to the only podcast delivering and deciphering the latest running research to help you run smarter. My name is Brody. I'm an online physiotherapist treating runners all over the world, but I'm also an advert runner who just like you have been through vicious injury cycles and when searching for answers, struggled to decipher between common. myths and real evidence-based guidance. But this podcast is changing that. So join me as a run smarter scholar and raise your running IQ so we can break through the injury cycles and achieve running feats you never thought possible. Thank you for joining me on another episode of the Run Smarter podcast. As we do at the end of every month, we go through the latest running research and there was a few common themes that popped up in terms of what was released in the research over the past four weeks. And there were three significant papers talking about advanced footwear technology, which we have come to know as the super shoe, carbon plated. high tech foam shoes and I thought why not clump them all together and do a dedicated episode on that particular topic. We're going to talk about a large review that was done talking about running economy performance with advanced footwear technology and another interesting one that came out was titled the impact of advanced footwear technology on running economy at slower running speeds. So are these super shoes just for the elites trying to scrape off seconds or is there some sort of advantage to someone's running economy when they're just a recreational runner, not really running that fast? And so I thought I'd highlight a few of those pieces and kind of bring it all together to see what the up-to-date consensus is when it comes to running, running shoes and performance. As I mentioned in previous episodes, I'm not gonna cover the entire paper. If I just look at this first one, I'm going to discuss it's 28 pages long. I'm not going to read through all of that. I've just highlighted some things that you might find interesting, but if you do want to deeper dive and you are a part of the run smarter database where you get access to the Google sheets and all of these papers, m you can dive deeper because there is a ton that I did miss. So if you are interested, have a look at it. The title is called the mechanisms, economy and performance of advanced footwear technology in endurance runners, a review. uh In terms of the file name, I've just titled it performance in advanced footwear. So you can locate it a bit quicker if you have access to the Google drive. And I think like, as I'll go through this, I think I'll just use the term Super shoe may not be extremely accurate because they like to use the term advanced footwear technology, but It's a bit more of a mouthful. I'd like just to say Super shoe. And as I go through this, they use the term advanced footwear technology in almost every single sentence. So I think if I just say Super shoe and just move on, I think it's a bit more free flowing. So just a bit of a caveat there. Let's start with this paper and then we'll get into the other two papers I have included. Let's start with the introduction. In recent years, increasing attention has been paid to the carbon-plated shoes. running shoes with an embedded carbon fiber plate in the midsole combined with multiple layers of specialized foam structures. I should point out if you haven't listened to my podcast interview with Simon Barthold, you can just search ah run smarter podcast Simon and you'll find that he dives into the super shoes and talks about the materials at play the properties and the carbon fiber plate and the mechanisms behind it all. But essentially the Super Shoe would be just uh certain characteristics. One, yes, a carbon fiber plate or some sort of uh stiff plate embedded within the shoe itself uh amongst a whole bunch of other technologies, including high tech foam, usually a very high stack height, um usually prompted up quite high. The heel drop, usually quite excessive. there's a bit of a rocker feel to it. So if you just place the shoe on the ground, the toes tend to point up more so. And so when you land the shoe just, I guess naturally rocks forward, um teeter totter, seesaw, whatever you want to call it sort of mechanism. um Plus, yeah, a few other features which we'll soon discuss. Although a growing number of studies have analyzed different brands and models of super shoes. there is still no clear consensus on the mechanisms that explain their effectiveness. Overall questions remain about how these shoes can be optimally applied to the individual athlete. The purpose of this review is to summarize and critically evaluate the dominant factors determining the working mechanisms of super shoes, highlighting their role in shaping running economy and performance. Running economy, if you're not familiar, would be... how efficient you are at moving through space, how much oxygen you consume when running at a certain speed. Running economy is very tightly linked to performance. If you run at a certain pace, and you're using less energy at that given pace, you're going to improve your performance. But if you run at a certain effort, and you say it's a five out of 10, and you can run faster at that effort compared to someone else, you're obviously going to improve performance. So that's what we're talking about when it comes to running economy. So the design of these super shoes, the construction of the carbon plated shoe can be conceptualized as a layered structure, often described as a sandwich consisting of multiple layers of varying types of thicknesses compressed together. Each of these elements, plate geometry, foam properties, longitudinal bending stiffness, the toe spring and the stack height has its role. and should be evaluated in the terms of a multifactorial interaction. So we're using like the toe spring, like I say, it's uh angled upwards. The foam, there's multiple layers of different densities of foam. There's the midsole sort of properties, so the mid portion of the shoe. The stack height would be like how high off the ground your foot is. And the plate in terms of like the type of plate, how much curvature it has, how rigid it is, all of these. mechanisms play an important role in it being different to a traditional shoe. So this is talking about the design. One of the subcategories within this paper is titled the plate geometry and the midsole materials. And so it says, usually defined as a key structural element of super shoes, the carbon fiber plate is either embedded within the shoe midsole or inserted directly into the shoe. These two placements differ significantly. Insertable carbon soles not surrounded by cushioning foam are stiffer and alter both the running feel and the perceived comfort. However, they tend to last longer and may be a more economical option than purchasing a new pair of carbon plated running shoes. Curved carbon plates are generally associated with greater improvements in running economy and performance compared to flat plates. not only looking at the plate itself, whether it's embedded or like inserted just within the shoe, but also does it have a curve to it? The curved plate seems to outperform. A distinctive feature of many Super shoe models is a rocker geometry characterized by a slight forefoot elevation or a toe spring that creates an S shaped sole design in which the heel sits slightly higher than the forefoot. in interaction with increased midsole longitudinal bending stiffness. So like if you take the shoe, uh you put one hand at the toe end, one hand at the heel end and you try and squeeze your hands together. uh That rigidity is what they call longitudinal bending stiffness. This configuration has been consistently associated with improvements in running economy. Recent studies indicate that the benefits may be runner specific. and an optimal shoe bending stiffness may exist for different individuals. The specific feature of the toe spring facilitates a faster and more efficient heel to toe transition, often described as a rollover or spring-like sensation, which helps to maintain a straighter alignment of the halux, we can just say like the big toe, reduced energy expenditure during push-off and shortened ground contact time. plate location is also an important factor, particularly in models with increased stiffness. The design of the forefoot plate, whether full length or segmented, can substantially alter running biomechanics and subsequently performance outcomes. In contrast, inappropriate plate curvature or stiffness may increase the risk of foot injuries. We'll have a talk about injuries a bit later. uh So that's just sort of looking at the midsole properties and the plate geometry for a bit of insight. Let's talk about the foam, the foam construction. So foam construction has been shown to play a particularly important role in interacting with the carbon fiber plates and may also influence the shoe durability during the foams microstructure. This is what Simon Bartol was talking about when I interviewed him on the podcast. He was saying that a lot of these uh records that have been broken and how fast these runners are may not be a lot to do with the plate. Maybe to do with this really high tech foam. He was saying that the foam technologies these days are just so advanced where they're so lightweight, yet quite stiff and can return a lot of energy. seeing his assumption is this is probably where a lot of people actually seeing benefits in their running economy. So the foam type that they use is really, really important. This paper continues to say that Amar et al. compared five commercial midsole foams derived from three of the most commonly used polymers in carbon fiber shoes. The three main foams that they used were EVA, PEBA and TPU. I don't really wanna try my best to pronounce all of the abbreviations, but just so you know, there are three main types of foam, high technology density foams used in these super shoes. Then under mechanical fatigue testing, it seems like the EVA foams reinforced with micro fillers demonstrated improved mechanical strength, reduced rebound properties and accelerated wear. In contrast, denser foams exhibited slower damage progression and enhanced durability. They'll get into the foams in a second, but it seemed like the EVA foams uh seem to be quite strong. superior to the others, but they degrade a lot quicker. Like I said, I'll talk about that a little bit more in a second. What about the stack height? So the stack height is how far your foot is off the ground. In these if you've ever wore like a super shoe, I will also say I don't have a lot of experience with super shoes. Definitely haven't used like any of the big like say Nike, Vaporfly or Alphalor or anything like that. I do have like a high rock specific shoe now which does have a plate in it. So I'm starting to do a couple of runs in those and get a feel for those. I don't think it would have as aggressive of a feel as something like a Nike Super shoe. But the one thing that I do realize is like the stack height is quite high and I do feel quite tall when I put them on compared to my usual minimalist shoes where I do feel very close to the ground. But the stack height is quite aggressive. So this paper says that functionally stack height acts like a compliant spring. A thicker midsole allows for greater elastic deformation during the foot strike. So if you have more foam underneath your foot, you have more ability for the foam to compress and release the subsequent energy release during push off and assisting in propulsion. This mechanism not only influences running economy, and biomechanics, but also affects comfort and the impact attenuation. Attenuation would be kind of like the rippling effect, like as you impact the ground, what happens to those shock waves as it sends through your body? It could attenuate if there is that foam, it could make it a bit more subtle, I guess you could say, but also comfort if there is more foam underneath your foot when you impact the ground. A recent study by Borman et al, confirmed that adding an additional 10 millimeters, of stack height to the current 40 millimeter limit improved running economy by 0.6 % during treadmill running and 0.7 % during overground running. So I think I don't know if it's changed, but in the elites running like they've put a cap or a limit or a restriction on super shoes saying that the stack height can will be no more than 40 millimeters. And so yeah, that's the rule that they've put in place, but there's a paper to say if you go to 50, if you put in an additional 10 millimeters to that limitation, then there is an additional improvement in running economy. Interestingly, though, this modification does not significantly affect perceived exertion rates or running kinematic variables such as cadence, flight time, contact time, duty factor, etc. Moreover, the shoe with the highest stack height, i.e. 50 millimeters, were rated the lowest in terms of subjective comfort. So people are just finding them way too foreign that the stack height is way too high. So the comfort level is low, but the running economy is actually high. Okay, let's look at the proposed working mechanisms. Why are these super shoes making people so fast? We've talked about the properties and the theory behind it. But let's dive a little bit deeper into the working mechanisms. One of it, one of them has to do with energy return. And the paper says, the store and release of elastic energy is recognized as one of the main factors for contributing to running economy in humans and animals. So when we impact the ground, we see that as storing energy, we have the potential to release that energy, or lose some of that energy, some of it is lost in sound or heat or attenuation or just like just not absorbing that energy quite well. But if we can take that stored energy of impact in the ground and contribute that or apply that to your forward momentum, i.e. store and release that energy, if you can do that really efficiently with not a lot of energy lost, then our running economy increases or improves. And so that's what we're talking about when we look at energy return mechanisms and we're talking about store and release and that sort of stuff. So the primary function of the energy return mechanisms in this footwear is to recover energy restored in the midsole during stance and return it to assist subsequent movement such as the swing phase. This process is associated with reduced oxygen consumption and improved running economy. It seems like the the like say the foam and the rocker and the plate all can have a contributing factor to returning this energy as efficiently as possible. But they also talk about the big toe, the metatarsophallangeal joint, which is just your big toe joint and the role the super shoes play on this. So the metatarsophallangeal joint plays a central role in running efficiency as its motion strongly influences mechanical energy transfer and potential energy loss during the push off phase. So carbon fiber plates are designed to limit excessive dorsiflexion or bending at this big toe joint, thereby reducing energy dissipation and enhancing effectiveness of energy transfer, which is generally associated with improved running economy. it's somewhat reducing excessive range at the big toe joint because if your big toe is excessively bending, you are losing energy or you're not transferring energy as efficiently. Thus the primary advantage of a super shoe lies in reducing energy dissipation rather than truly increasing energy return. not the shoe isn't generating energy and pushing you forward, it's just making it more efficient so that you're losing less energy in that potential energy gained when hitting the ground. Accordingly footwear development should prioritize strategies to minimize energy loss, rather than attempting to maximize energy return. Next up on this paper, they talk about the materials and the mechanical properties of the carbon plated chew. So we're looking at ah looking more into the carbon plate aspect of things. Recent studies indicate that the type of sole material and its mechanical properties may have a greater impact on running economy efficiency and fatigue resistance rather than the longitudinal bending stiffness. Running shoes with more resistant and compliant mid-soles can reduce ATP consumption during muscle contraction, producing the same force with lower oxygen cost at any running intensity. Remember we had those three type of foam that they use, the EVA, the TPU and the PEBAs. They say that the PEBAs, which is Polyether block amide is considered one of the most efficient materials for energy return. I think this is in the Nike Vaporfly and the Nike Alpha Fly. I this is the type of foam they use. Its low density allows for greater cushioning volume without significantly increasing shoe mass. So good properties of the foam, but we're not sacrificing weight. It's still very, very light. Despite these favorable mechanical properties, The PABAs low density results in faster wear compared with conventional materials. This compromises the durability and long-term impact on running economy. There was a paper from Rodrigo Carranza et al found that while new PABA shoes improved running economy more than the EVA shoes, after 450 kilometers of use, the materials were similar. So comparing to super shoe foams, the superior one became less superior after 450 kilometres. So preservation of the shoes can be important and is a pretty key takeaway from this paper. Another subcategory on here was talking about super shoes and running injuries. So what does this paper have to say? The changes in running biomechanics caused by super shoes can sometimes produce inadequate sensations for the athletes. Increased midsole cushioning common to nearly all super shoe models allow for a reduction in the flexion. So you are at contact when your foot impacts the ground. The leg is a little bit straighter, you could say. This encourages more rear foot striking without the running without the runner perceiving the same impact as a conventional shoe, or even more so barefoot running. However, the absence of immediate discomfort, like I say, they're not really appreciating that they're impacting the ground with a straighter leg, the absence of this immediate discomfort does not mean that the bones, joints and ligaments remain unaffected. A recent study by Borman et al. indicated a potential increase in lower limb loading when running in super shoes. Over time, the passive musculoskeletal system may struggle to tolerate and recover from altered loading, increasing the risk of overuse injuries. Increased heel striking could also elevate the risk of rear foot injuries, particularly when running on stiffer surfaces. Although direct evidence is limited, case reports describe stress reactions and stress fractures of the midfoot, in particular the navicular bone region, in athletes using carbon-plated shoes at the time of injury. So you may be impacting the ground with a straight toe leg, maybe with a little bit more heel contact, but not... on the conscious level. ah But that's still different loading to the body. And if done excessively and not allowing for that adaptation phase to occur, if it's too abrupt, that could definitely increase the risk of stress reactions, bone stress fractures, those sorts of things. ah I have done, I'm not sure the actual reference that they commented in here, but I have done an episode in the past of a uh Not it was kind of like a clinic clinical commentary paper, where the authors were commenting on case studies that they've seen when people have done an abrupt transition to super shoes, and this navicular stress fracture uh occurrence was happening, and encouraging the population while bringing awareness to the running community and encouraging them to have a slower transition in these shoes. Gradual integration of super shoes into training is required. This approach allows runners to adapt their musculoskeletal systems and gait patterns while reducing potential overuse injuries and optimizing the advances of footwear technology. So just a, they just mentioned slow transition, gradual transition is appropriate. Next on the agenda as the paper generally promotes is the effects of super shoes on running economy and performance. where do we lie in terms of its direct evidence? Despite extensive study, the findings on super shoes remain inconsistent. Reported outcomes range from significant improvements to no measurable effect or even negative effect on running economy and performance. Placebo effects may also be proposed and were recently demonstrated in recreational runners. Many studies have reported an improvement of running economy of around about 4%. for super shoes. Investigations on the Vaporfly and AlphaFly have demonstrated faster times in a controlled 3K and 5K trial. Hukama et al. reported an average 4 % improvement in running economy at 14 to 18 kilometers per hour when running with the Vaporfly prototype compared to a Nike Zoom Streak 6 despite equalized shoe mass. In contrast, Healy et al. cut the vapor flyers carbon plate and found no significant change in running economy, suggesting that the plate alone does not explain the performance benefits. I actually found this quite intriguing actually went diving a bit deeper into that actual paper and they have photos of it. They took the vapor fly and cut like literally sawed several different cross-sectional like from the the sole upwards, uh cut into the plate several times. and then just had people like not cut all the way through the shoe, only just partially so that it intersects the plate and then just had people run in it, see if there was any difference. And so it seems like the performance benefits are still carried over when they've cut through the plate. So the plate is no longer that effective. um And so maybe there are other mechanisms of place, i.e. like we've discussed before, the rocker, the foam, densities and all the other properties that come along with it. So Super Shoe Outcomes. appear to depend on multiple interacting factors. The internal influences include the individual response to the specific shoe models, the training level and genetics of the runner, the biomechanical, physiological and anthropometric characteristics of the runner itself. But there's also external factors that may produce these differences that involves the surface stiffness. the running velocity, the race distance, and the shoe mass. All of these are different and can produce different outcomes, which is why we may be seeing different results in these studies. So the design features such as midsole, bending stiffness, the foam compliance and resilience, the plate type, the plate curvature, the stack height, could all manipulate these outcomes. However, collectively, these findings indicate that the Super shoe related improvements in running economy and performance arise from multiple interacting factors rather than a single feature such as the carbon plate. I would say all in all, there's definitely robust evidence to show that this does, super shoes do improve running economy and performance seems to be in the most rigorous studies around about three to 4 % improvement. I just thought I'd... go through a few quick mentions. I skipped a couple of these sections talking about uh race distance talking about surface and like the specific interactions around those. But wanted to have a quick comment on the fatigue resistance. So super shoes and fatigue resistance, they say a growing body of research has linked super shoes to improved neuromuscular fatigue resistance in long distance running. These effects suggest that super shoes may not only help maintain performance. but also the delay, the fatigue related declines in running economy, offering better potential or potential benefits to endurance athletes beyond immediate performance. So while they're fresh and running and improves the running economy, people may stay fresher for longer in these endurance races, which is, you know, obviously contributing to greater performance. Also a quick mention to the role of foot strike patterns. They say that foot strike related kinematics may positively, negatively or neutrally affect running economy. And they say that no single running style has been proven superior with these super shoes, although emerging evidence points to potential trends, warranting further investigation. And lastly, for this paper, before we move on to some others, what are the practical implications? They say these findings highlight the importance of a personalized approach, gradual integration and fair use boundaries in the application of super shoes. Progressive integration of super shoes into training is necessary to allow for the musculoskeletal system to adapt. And finally, running velocity should be carefully considered and strategically leveraged when selecting super shoes as it determines both performance outcomes and the ability to fully utilize the shoes potential. This next paper is quite similar in terms of topic, but was released at the same time and is a systematic review and meta-analysis. And so worth reviewing, seeing if there's anything different, but I'll try to not repeat myself too much with the topic being quite similar. So the title of this paper is the metabolic effects of carbon plated running shoes, a systematic review and meta analysis. They conducted this systematic review as to analyze crossover trials comparing plated versus don plated running shoes in healthy adults. They did their search criterion came up with 14 studies that met their uh inclusion criteria. The population that they chose was healthy adult runners between 18 and 60 years old. And the intervention was obviously a carbon plated shoe in comparison with the any sort of non carbon plated based shoe and their outcomes were looking at running economy and or metabolic cost and or oxygen consumption and or energetic cost of transport. And I think they're all just very similar terms to mean a very similar thing. So like I said, there was 14 papers that have been released that they wanted to all compare and see if there's uh general consensus with the findings. So I'm just going to skip ahead to everything that was discussed in the discussion. And then we'll move on to the third paper. So they say across all outcomes, Footwear containing a full length carbon plate demonstrated small to moderate improvements in metabolic surrogates of endurance performance compared with non-plated models. Reductions in running economy, metabolic cost, oxygen consumption and energetic cost were statistically significant in pooled analyses and directionally consistent with the concept that increased longitudinal bending stiffness can confer metabolic savings. A central challenge in interpreting these results lies in distinguishing the independent contribution of the plate from that of other co-occurring design elements such as higher return foam, rocker geometrics, increased stack height and variations in shoe mass. Meaning, surely try to attempt to see how effective is this carbon plate, but it's very hard to unravel, disentangle the Benefits of the plate without also considering all the other features that come along with these super shoes. Very hard to, yeah, separate them out because they're obviously going to be embedded in foams is obviously going to be the rocker style, the stack height and all those changes that you see. When midsole material and geometry were matched as in for prototype studies, plate inserted with the plate insertion generally favored lower metabolic demands suggesting that this longitudinal bending stiffness specific component was effective. When analyzed by outcome and pulled the mean difference in running economy, the benefits were approximately equal to 2.9%. This supports a plate related metabolic advantage. Some of the differences in findings likely are reflected based on the different testing speeds since the stiffer setups tend to perform better at higher velocities. We'll talk about that soon. And because an increased shoe mass definitely affects metabolic cost or energy cost, uh part of the observed benefit may be confounded when the plated model is also lighter. Nonetheless, studies that tightly matched shoe mass also demonstrated a plate related advantage. So like I say, it's hard to disentangle. but when they did manage to somewhat disentangle the benefits, so like with prototype shoes when they just had a fiber plate inserted and all other geometry and material being identical, does seem that it still had some benefits and when matching for the weight of the shoe, also those with the plate tended to have some benefits as well. Mechanistically, the plate appears to act through several pathways by increasing the longitudinal bending stiffness and altering the metatarsophallangeal joint, which we've discussed before, and also ankle energetics by interacting with the midsole to promote the rocker lever mechanisms, that teeter-totter effect that may reduce distal work and by redistributing the work without necessarily increasing overall muscle activation. kind of coincides and links up with the previous paper. So good to see a common narrative there. Overall, the mean metabolic savings of approximately 2.75 % aligns with the prior modeling that links a two to 3 % reduction in energetic cost to an expected performance improvement of roughly 1 % in marathon times. So while it is a two to 3 % reduction in cost or efficiency, it roughly leads to a 1 % improvement in marathon time. So translating that way, if you want to take a look at the full paper, you can obviously go do that if you had access to it. But I want to shift gears a little bit because there is a slight different approach in this third paper that I want to discuss the title as I mentioned before was the impact of advanced footwear technology on running economy at slower running speeds, a randomized crossover investigation. And yeah, it's, it's an interesting debate as to how much advantage this would have like these types of shoes have on recreational runners. I know Simon Bartol when I interviewed him said these typically are for the best of the best, the elites that are looking to squeeze out some good, um like to take full advantage of the shoe. However, we did say that recreational runners do seem to get improvements in their running performance, but he seemed to think it was mainly placebo. ah I don't know, maybe after several years of research coming out, maybe you think it's differently, but anyway, ah this paper, as I'll skip through just what I've highlighted, they say that the goal of this study was to assess the effects of the Super Shoe at slower speeds in three different footwear conditions. including a traditional shoe, which they used a on cloud runner to they used a super shoe optimized for performance at high speeds. They use the on cloud boom echo three and a shoe with combined features. So it had the sort of combined features of a super shoe and also a traditional shoe. And they, it was, they labeled it as an on prototype. So maybe just not a commercially available shoe. They just mixed the two, but it's good to see they have a mixed shoe in there to study. so based on these results of the previous research, their hypothesis is that one, there would be benefits in oxygen cost at lower speeds, but they would diminish with decreasing velocities. So as it's clear in the evidence that there is an enhanced running economy with these super shoes, but maybe the difference or maybe that enhanced benefit becomes more and more diminished as the speeds come down. The general design of the study, ah had the participants visited a lab on three different occasions, each separated by three to seven days. And the same running protocol was followed on each occasion to ensure a robust set of data. They said that 16 recreational runners were initially recruited for the study. However, two male participants didn't get to the end, didn't complete. So that left us with six male participants and eight female participants. And so on visit one, they went through a questionnaire, they did some basic testing, they looked at their height, weight, leg length. They also did a incremental treadmill test to look at their uh peak aerobic capacity or their VO2 max. And like I said, there was three different occasions that they came into the lab for testing. And they went through this running protocol. The protocol began with a standardized incremental warmup. So two minutes at seven and a half case per hour on the treadmill, then one minute at nine case, one minute at 10 and a half case, one minute at 12 case. And so they aren't really fast speeds. But after a five minute break, The test protocol started which consisted of three 14 minute runs intersected by 20 minutes of rest. So 14 minutes on 20 minute rest 14 on 20 rest uh where each of the 14 minute runs were performed with one of the tested shoes. Like I said, there were three shoes that were tested the traditional the super shoe and the mixed each run started with a five minute stage of seven and a half case per hour followed by a three three minute stages at nine, 10, 10 and a half, sorry, at nine, 10 and a half and 12 Ks per hour respectively. 30 seconds prior to each of the stages, participants were asked to rate their perceived effort out of 10. After completing each run, the participants were requested to fill out the questionnaire to assess their experience with that tested footwear, including their perceptions related to general comfort, energy return, springiness and the overall satisfaction. So that was the conduction of the study. What did they find? Let's look at the discussion. So while the super shoes provided the expected metabolic savings compared with a traditional shoe, in contrast to current literature and our own hypothesis, the differences in running economy persisted even when testing at seven and a half Ks per hour. Our second hypothesis was likewise not supported by our results. as there was no relevant difference in the tempurospatial variables between footwear conditions and could explain the differences in metabolic cost between the different shoes. So they didn't, the runners didn't move differently. They didn't change their cadence or step length or anything, but they were still seeing enhancements in their running efficiency. The difference in running economy between the super shoes and the traditional shoes reported in the present study is in line with our previous investigation of the same shoes at 16 kph with well-trained runners. In the present study, the oxygen cost improved between 2.3 to 3.1 % comparing the Super shoe and the traditional shoe over the tested speed range. These findings, are in stark contrast with previous suggestions that the benefits of Super shoes disappear at lower speeds. Both previous studies, however, used either single or two runs per speed and in shoe tested, which could have increased the result variability. In conclusion, super shoes can provide reduced reduction in oxygen cost of running over a large range of slower running speeds. So an interesting finding to uncover there. So overall, what can we take away from these three papers? I'd say one, the most... insightful revelations is that Super Shoes, the narrative around Super Shoes only helping fast runners is quite outdated. So they tested between 7.5 and 12 kilometers per hour. And this sort of kind of reflects your easy runs, your long runs, especially like most recreational marathon paces. uh And so that's good. We expect probably that same two to 3 % improvement in running economy across all speeds. Excellent insight. The other thing, sort of hard to know, but like the carbon plate itself doesn't matter too much on its own. It's seeming like it has this synergistic effect with different properties of the shoe. So the plate versus the foam, um you know, it seems like it has this super shoe kind of package effect where we're combining a whole bunch of those different features. The foam, the bending stiffness, the rocker geometry, the shoe mass as well, all of this. has a synergy effect to create the benefits. One thing I didn't really highlight in here, but like the comfort measured doesn't really predict running economy. So this was quite surprising. So even like in that slower speed paper, that third one we mentioned, they found that like comfort drives preference, but the economy drives performance. There wasn't necessarily a correlation. The comfort did not correlate with better running economy. Um, so just interesting to know there, the biomechanics that that whole narrative is a bit smaller than we initially thought. So you might expect that in these super shoes, you might have a shorter contact time, increased cadence, higher leg stiffness, sorts of things. But, um, this third study sort of found that people didn't really change how they moved. Leg stiffness didn't really change too much. um Whereas those previous studies that looked at kind of higher speeds showed that there might be a subtle change, slight stiffer landing, that sort of stuff. And, you know, these are meaningful differences like the metabolic saving is not that small, like across the meta-analyses, like all of these things, there seems to be a metabolic improvement of around about 2.75%. So to translate that, if we just roughly just round up and say a 3 % improvement in running economy, and around about a 1 % improvement in marathon times. For your standard four hour marathoner, it's improvement of three minutes, which isn't trivial. I guess that, you know, that's something that people want to be aware of if they're trying to qualify for certain times or beat their PBs. um This is at no change or no increase in effort. So yeah, it can be significant. I think for the elites, it was like a 20 something. 20 or 30 second difference, something like that. The last thing I'll say just as a takeaway is just to be mindful of injuries. Like these studies um do highlight the importance of ah transitioning into these shoes gradually, and just making sure that we're paying attention to symptoms. If you do notice any sort of foot pain with these, don't persist and run hard and run fast in them. um Surefire way of developing a stress fracture. ah But also, know shoe preservation might be something helpful as well if you want to continue seeing improvement in performance or taking advantage of this shoe does seem to especially if you're in this really high tech the PEBA style style foam can degrade over time and the benefits the enhancements that you get the advantage that you take with the shoe can slowly degrade over time so just bear that in mind as well. um So super shoe update hopefully you um learnt a few things. Hopefully you can take away some practical lessons from what we've uncovered in these recent papers. m You can go check out those papers now if you do have access to this database. If you want access to the database, check out the link in the show notes and we'll catch you in the next episode. If you are looking for more resources to run smarter or you'd like to jump on a free 20 minute injury chat with me, then click on the resources link in the show notes. There you'll find a link to schedule a call, plus free resources like my very popular Injury Prevention 5 Day Course. You'll also find the Run Smarter book and ways you can access my ever-growing treasure trove of running research papers. Thanks once again for joining me and well done on prioritising your running wisdom.