Welcome to the Empirical Cycling Podcast. I'm your host, Kolie Moore, joined by my co-host, Kyle Helson. And as always, I want to thank everyone for listening. Please subscribe. We are also now on Google Play. So if that's how you listen to podcasts, you can find us there now too. For any questions, comments, or coaching inquiries, please send an email to empiricalcycling at gmail.com. And if you'd like to support the podcast, I'm actually doing something a little special because I am re-recording the intro because any donations made... from the release of this episode until July 6th are going to go to Kyle and Michelle as a wedding gift from you, the listeners. So if you'd like to give to that, it's going to be a little surprise because Kyle usually doesn't listen to the episodes after they're released. So here we go. And with that, I want to say that I'm very excited for this episode today because this is the first of... Nerd! I know. Okay, so it's the first of a lot of episodes. Where we're going to be talking about muscle physiology, which is one of the aspects of training that's really crucial to understand what's actually happening in the body when you assign training or when you do things like strength training like we're going to talk about today. And by the end of the episode, I hope you're going to see why. So one of the other cool things about this episode is that we're actually going to bring you right to the edge of our scientific understanding of how the body works. This one really goes into some cutting-edge research. We're not going to be talking about a lot of those papers at this moment. We're actually going to be reviewing one of the papers that I picked to talk about some of the common misconceptions about how strength training affects endurance training. So one of the things that we're going to be focusing on today is those strength training myths and stuff like that. So Kyle, what do you know about these common strength training myths and what do you see typically bandied about? Well, I think the first question that people usually have is, is strength training good for endurance athletes? We touched on this a little bit briefly in a different episode. And secondly, there is a certain camp of people out there who likes to think that Doing strength training and resistance training is actually going to improve your aerobic abilities and so there are programs built around the theory that oh if I get stronger in the gym I will see my FTP or VO2 max go up and that may or may not actually be the case. Yeah, it's a complicated matter. And one of the things that we're going to touch on today that we will, as always, get into in great depth in another episode is, you know, like what does power output really mean physiologically? So in terms of strength training, there's actually a lot of different studies that show a lot of different things about The Effects of Strength Training on Endurance Performance. And as always, these studies are conflicting. One of the common problems that we see in these studies is the test groups. And, you know, commonly they're untrained or just recreationally active. The test groups are very small, so we have small sample sizes. Individual results are not reported, so we might be able to see different effects with different people individually. Sometimes there are trained endurance participants who never strength trained and sometimes there are people who've never quite done enough of each to really improve beyond the new gains phase. And then also the protocols done in the methods of a lot of these studies don't really match what's commonly done. So some of these training protocols and some of the testing protocols that are used can also be highly questionable. And a lot of those things make sense if you consider that these are scientific studies. They're not necessarily studies put on by, say, coaches from a national team somewhere trying to actually figure out a good protocol for training athletes. All right. So one of the things that bugs me about a lot of the strength training methods out there for cyclists is that they are oftentimes not cycling specific. So like you said, like if there's a coach for a national team or something like that and somebody's trying to look at, you know, cutting down strength training to the bare bones of like what exactly do we need and what exactly does it do, like those are going to be great studies and protocols. Unfortunately, there are almost none of those out there. And so what we really have are people who come from traditions of Olympic lifting. Powerlifting, Bodybuilding, and Traditional Team Sports Strength and Conditioning, none of which are really too specific to cycling. However, a lot of the time when we see people undergo some of these strength training programs, they do see improvements in power output. So we're going to actually go through some of the mechanisms that are typically bandied about. in order to explain why lifting weights can make you a faster cyclist. But also we're going to go into some of the details about some of the trade-offs that are going to happen when you do lift weights and possibly if you do lift weights too much. All right, so to get to the study that we're going to look at in great depth today. I actually have a link to it up on the website empiricalcycling.com and under the podcast episodes we have the show notes for the show and this is going to be the first link. So this study looked at elite under 23 team members. So again as always one of the potential pitfalls with our training population is that these could possibly be natural talents that are not at full training maturity. and also one of the other problems with the study is that individual results are not reported. This study broke the participants up into two groups, endurance and strength and endurance. So they did 16 weeks of training and the endurance group did 10 to 18 hours of endurance riding per week. It wasn't anything harder than that as far as I can tell in the protocol of the study. It was just endurance riding and the strength and endurance group. did the same riding except two to three times a week. They went in and did very heavy weightlifting after a two or three week conditioning period and where they were doing five to six rep max as their load. So, you know, Kyle, doesn't that sound kind of like most of the strength plans we see for road cyclists? Yeah, I think even beyond just looking at your typical strength, maximum strength phase for a lot of team sports or even powerlifting, weightlifting, it's that sets of five to six are typically viewed as being the ones where you make the biggest gains in terms of strength. I think if you look at the Cyclist Training Bible by Friel, his like maximum strength phase in his lifting program for cyclists. does have this very similar sets of five to six. And if you look up a lot of intro bodybuilding, powerlifting, weightlifting programs, it's three sets of five, five sets of five, stuff like that. So it's really common. Yeah, exactly. And so that's one of the reasons that I kind of like the study to talk about today is that this is something that you would... pretty typically see a road cyclist do during their base period. It was just a lot of long miles in the saddle and some heavy lifting and, you know, probably one or two other things, but not like focused intensive training. Yeah, so I thought that this was a really cool study to look at because this actually does look like a lot of the training that people would typically do. All right, so here's a quick summary of the results and we're going to get into the hows and whys of all of these. So, during this test period, 16 weeks, VO2 max and FTP were unchanged. That is one of the most important things to remember about this study. Now, 5-minute power went up by 3-4% in both groups. 45-minute power, so they did an endurance test as a 45-minute time trial, went up 8% or about 15 watts. in the strength and endurance group, but not in the endurance group. So something to consider here is actually training specificity. So if you're doing heavy lifting sets of five, something like that, what are you specifically training that's going to make a 45-minute power go up? And part of it may be a little strange because you would think that's very aerobic power, and it is, but we're actually going to go through a lot of the plausible mechanisms, including a bunch that were done in the study, and then we're actually going to get to the real mechanism that was actually not talked about in the paper that only very recent science has begun to elucidate. So thinking about that, when we think about the 45-minute power test, I just want to point out really quick that this is Almost definitely over FTP for all of the test participants because once you're an elite cyclist, your FTP is pretty typically has a time to exhaustion between 60 and 80 minutes. So most people who go time trial for like 30, 45, 50 minutes who are elite cyclists are almost always time trialing over their FTP. I think that's a good point and something to keep in mind, especially when you look at this. Study done with elite athletes as opposed to studies done with weekend warrior, sedentary, more average looking people. Yeah, exactly. And as we discussed in all of our FTP episodes so far, is that as you become better and better trained, your time to exhaustion goes out and out and out. And especially once you become very well trained, that kind of thing does not go away very easily. Okay. And so now that we've kind of gone over the... Results of the study, we're now going to talk about several of the common theories as to why these results were seen for the strength plus endurance group compared to the endurance only group. The first one is not super common one, but it exists out there that this extra lifting, the extra resistance or strength training that they were doing, is actually going to improve their aerobic capacity. But I think if you look at the conclusions of the results that we said before, if their VO2 max and their FTP were unchanged, then the lifting did not have an impact on their aerobic abilities. Though there are studies that you can find out there where you do see aerobic increases, aerobic ability increases in populations. After they undergo strength training. But more often than not, those are going to be people who are very untrained or relatively untrained who have no sort of formal history within sports or training or working out. And so for them, they're still in the phase of this sort of quote-unquote noob gains where doing any type of training is going to make all of their physiological Markers go up. So they can lift a bunch of weights and their view to max will probably go up a little bit or their FTP will probably go up to a little bit. And this population is distinctly different from this well-trained endurance, elite endurance cyclist population. And so one of the things that is important to note is that oxygen uptake is limited. and Elite Athletes by central factors. So your heart, your lungs, your cardiovascular system. And the utilization is peripherally limited by metabolic rate and, hint, hint, muscular factors, which we're going to get into. And so it's not surprising to me that FTP didn't go up with the strength training group because strength training does not directly have a metabolic effect that is anything FTP-like. And, you know, it doesn't increase VO2 max because it's not stressing your cardiovascular system enough in order to make that, you know, in order to make it deliver more oxygen to your muscles. All right, so the next theory that you might see out there is that More muscle mass will lead to better power output. So did the strength and endurance group build muscle? The answer is no. Their weight stayed the same. Muscle size stayed the same. But to be fair, there are other studies that see an increase in muscle size and particularly an increase in type 2, that's fast twitch muscle fibers. And one of the reasons that this group may not have gained any muscle is that there's potentially an interference mechanism that we've discussed in previous episodes, the one on can you lift heavy while endurance training. And so what is probably happening here is since the aerobic pathway actually attenuates the strength pathway, That basically means that aerobic pathway takes precedence. And that if you're riding enough, as these cyclists obviously were, it's probably going to impede your body from creating muscle mass. So that's one of the takeaways that you can take from this is that, you know, we can actually use those pathways to our advantage if we want them to be conflicting. Like we don't always have to build muscle. And in fact, you know, a lot of road cyclists don't want to or don't need to. And so if you do want to do some strength training, this is one of the cool things that you can do. One of the interesting things that happened with the strength and endurance group in this study is that their maximal voluntary contraction force went up 12 to 20%. That was the range. And this was likely from an increase of neural drive. And we'll get to that in a little bit. So the reason that, okay, so maximal voluntary contraction, just to define it real quick, is the largest amount of force that you can produce by your muscles. under your own will. There are ways to actually check the muscle fibers to see what they can do maximally, but we're not going to get into that. One of the things you can look at is if anyone has ever had the unfortunate injury of tearing an ACL, one of the things they'll put you on to see if you're able to return to training as normal is this machine that looks kind of like a leg extension or a leg curl machine, but it Resists as hard as you can straightening your knee and then again resists as hard as you can bending your knee to measure how much force you're actually able to produce. And so they can rig up other machines like this to measure other joints and things like that, but maximum contractile force can be measured on various lab implements like that. Right, and so as you recover from the injury or say as you adapt to strength training, you are actually going to be able to produce more force. You're going to be able to contract your existing muscles harder. All right, so next I want to get into one of the more common and slightly more complex theories that I commonly see about how strength training can improve endurance performance. So this one is actually one of the ones that I see most commonly in the scientific literature. The theory is that if you are increasing the maximal amount of force you can produce, then you're making the force required at submaximal intensities easier and less costly. So, okay, so we actually have some numbers to get into. So, okay, so for example, let's say you're doing 400 watts at 100 RPM. Now this requires about 220 newtons of force applied to the pedals consistently. So we can, you know, estimate peak force during a pedal stroke because it does, you know, you are a little stronger on the front of the pedal stroke around, you know, two, three, four o'clock. So we can estimate that's around 275 newtons or so. So now if we want to relate this directly to the study, we can estimate the participants FTP somewhere around 280 to 300 watts. Since 315 watts is a little bit over FTP, it's probably a reasonable estimate. So in order to maintain 280 to 300 watts at a cadence of about 95 to 100 RPM, you are actually going to have to average about 170 newtons. on the pedals, on standard length cranks. It doesn't change that much with cranks getting longer or shorter. So if the participants increase their maximal force that they can produce on the bike, the numbers I have for an average roadie is about 1,000 newtons maximally. So if you increase the force that you can produce from 1,000 newtons to 1,100 newtons, you have now brought down the requirement the force requirement to maintain your FTP from 15%, I'm sorry, from 16% to a little under 15%, which is not much. And we see an 8% improvement in 45-minute time trial here. So, you know, it's pretty obviously not that the force of the pedaling got easier because Here's one of the things about specificity is that there are different limiters to pedaling a long time at FTP and it's not the amount of maximal force that you can produce on the bike. You know, if you increase your one rep max by like 10 kilos, 20 kilos, you know, you're barely making a dent into like lowering the percentage of force required. 200 and some odd newtons to a maximal force of well over a thousand newtons, you know, you're already so far down in terms of what one pedal stroke requires in terms of maximal percentage that even if you doubled the maximum amount of force you could produce, you're lowering it from, you know, oh, I can produce some... 8% of your one rep max down to like 4 or something like that. Exactly, yeah. Yeah, and you know, at like FTP or endurance pace, you know, it's going to be even lower than that. Okay, so one of the big problems with this theory is that strength, maximal force that can be produced by the muscles is not really that related to a sustained demand for ATP. There are different requirements to put out 200 watts for several hours than to lift a couple, you know, 100 kilos or something like that. Right. I think it's a poor extrapolation of the idea that, oh, if I can, if my one rep max squat is 100 kilos, well, then I can do 75 kilos for More Reps, and if my one rep max goes up to 150 kilos, well I can do that 75 kilos for more reps than I could when my max was 100. But now we're looking at loads and forces that are so far away that the systems, the metabolic systems required to produce that one rep max back squat aren't really related to the systems required to pedal around your bike for four hours. Yeah, exactly. And also, just as a little teaser, is that a lot of people are capable of really defying the typical number of reps that people can produce at different percentages of their one rep max based on things like their fiber type and their metabolic fitness, like you might say their FTP or their VO2 max and stuff like that, because even once you get down to like eight rep max, 10 rep max, You know, you are starting to already get into some of these different metabolic systems that are capable of producing, you know, sustained ATP demands. So if we can see some of these aerobic ability, letting them do more reps at a high percentage of their one rep max, like 70%, 80%, then you would see expected in a lot of strength and conditioning books. We can tell that somebody's aerobic fitness is already having a very large part determining how many of these reps that you can do. And if you're aerobically better, you can do more reps because you can create more ATP aerobically and it's less to do with your maximal amount of force that you can produce. So if we're seeing this... at 8 or 10 or 12 reps and even as little as 2 or 3 reps, 95% of your 1 rep max, we can already see these effects. Imagine what it's going to be like when we're down at 4% of your 1 rep max or 10 or 12 or 15% of your 1 rep max. You are so more limited by your aerobic abilities than the amount of actual force that you can produce with your muscle fibers. That's going to be something else to delve into very deeply in a future podcast episode. We're just going to leave it right there for now. So the question is, did the strength and endurance group change any properties of their muscle fibers, like fast twitch, slow twitch? And the answer is, yes, they did. So one of the most obvious things that happened with them is that their Type IIx fibers, this is their very fast twitch, that have very low oxidative capacity turned into Type IIa fibers and almost a total interconversion. But there is a caveat to this that we'll get to in a little bit that has to do with neural drive and the main topic that we're getting to of the podcast today. Yes, so Type IIa fibers have better oxidative capacity than Type IIx, but don't go grabbing a barbell just yet. So I'm going to hint that there are other methods to achieve this type of fiber interconversion on a bike without hitting the weight room, and we'll probably hint at some in the future or even a little later in this episode, but they're kind of a trade secret, so we may or may not get into that in a future episode if I want to give away a secret like that. The other important thing that happened in this study is that Type I fiber percentage went down a little bit, but not to a point where it's statistically significant. Though this is something that we've talked about before in other studies on the podcast and something I see very commonly reading the literature is that when people start doing high-intensity training or strength training and the... The training protocol is like 8 to 16 or so weeks long. 16 is actually pretty long, but what typically happens is the Type I fibers actually start to convert a little bit into Type II. Not statistically significant, but it is a definite trend across a lot of studies. So this is something to consider is that in the long term, if you actually want less Type I fibers, Let's say you're a track racer or something like that and this might be a good thing for you. You need to sprint a lot. Yeah, then lifting a lot and not riding as much to convert your muscle fiber type, that would be beneficial for you. But for most endurance athletes, this is actually not beneficial. If you start strength training and you might have gained 1% or 2% slow twitch fibers, which If you're a highly trained athlete, those are very, very valuable, especially if you're like a road racer, you do any kind of long events, and you may not want to do too much strength training because every half a percent of Type I 5ers that you pick up is going to be hugely advantageous to you. So there are trade-offs, as we hinted, and this is one of the big ones, that if you do not enough endurance riding and too much strength training, and you don't want those fast twitch muscle fibers, you know, that is something to consider in your plan, but there's no right or wrong answer. So we'll get into why in just a minute, why the Type IIx to Type IIa conversion might look beneficial, but in reality, it may not actually have made a difference at all. And we're going to get to why about that in just a minute. The thing that people probably gravitate to the most when they see the, if they just read the title of the study and then skip to the conclusions is that the 45 minute test for the strength plus endurance group actually increased 8%. So they went from an average of about 315 watts to 340 watts and pretty much everyone out there is going to go Oh man, I could definitely use those 25 watts. Like, whoa, whoa, whoa. I'm going to sign up for my gym membership right away if that means that I gain 25 watts in my 45-minute test. Right. And so thinking about everything that we just talked about, along with thinking about that their lactate-tested FTP did not change, VO2Max did not change. So what was it that lifting trained specifically to get this result? Well, I'm going to tell you, and it has to do with something called the size principle, sometimes known as the Henneman size principle, but I know a lot of science is trying to get rid of, especially physiology, trying to get rid of the names of people, so, you know, Krebs cycle becomes tricarbic silk acid cycle and stuff like that. So, we're going to start talking about the size principle by talking about the motor unit, which I believe I mentioned briefly earlier. So, the motor unit starts with the motor neuron. connects to a bunch of individual muscle fibers in a muscle. So the brain connects to this muscle and the motor neuron carries the signal to these different muscle fibers. The motor neuron attaches to different numbers of muscle fibers in a muscle. Small motor units can attach to, the numbers I have here from the literature are 10 to 180 muscle fibers and the largest motor units can attach to 300 to 800 muscle fibers. Now the muscle fibers that each attaches to are in a range of slow and fast twitch, but there's a pattern. The pattern is that your smaller motor units are going to be slower twitch, and your largest motor units are going to be very, very fast twitch. And which you are going to use actually depends on the force requirements. But just a quick note, splitting up muscle fibers into fast and slow twitch is actually a convenience that we're going to use right now, although it is a lot more complicated. We can divide up fiber types by the MADPAs, the Myosin Heavy Chain, or biochemically. So we're just going to think about it mechanically in terms of fast twitch or slow twitch, and that's just the rate at which they contract. and we're going to get into a lot more detail in muscle fibers in another episode so we don't want to spend too much time on it now but slow twitch is the muscle fibers that are really good at using oxygen and doing things with a lot of fatigue resistance and fast twitch muscle fibers fatigue a lot more quickly and they are not nearly as good with oxygen although they certainly do use oxygen so the other important thing to know about a motor unit is that When the signal to contract gets sent out, it has to hit a certain threshold. And when this threshold is hit, all of the individual muscle fibers attached to this motor unit all contract. And it's an all or nothing thing. And the way we get gradations of force is by recruiting more or less motor units. So, in other words, the highest Threshold Motor Units, the very largest motor units you have, the 800 muscle fiber motor units, the big fast twitch ones, those require a very large, very strong signal. I think an example for some people out there, if you ever tried to pick up something that was very heavy and close to the maximum amount of weight that you could pick up, say in like a trap bar deadlift, you'll notice that you first start pulling and you're thinking like really hard about it. and it doesn't actually move and it takes a minute for all of a sudden your brain to tell enough of your muscles to fire hard to pick up this very heavy one rep max drop bar deadlifter or move this car off of this trapped child who the car is on fire or whatever. You can actually see this sort of thing happening in real time if you look at versus You compare a very slow, maximum attempt like that to a very easy, oh, you don't have to think about picking up 10 pounds off the ground. Now, here's the size principle, is that motor units, and indirectly muscle fibers, are recruited in order from smallest to largest to meet force production demands. So if your brain figures we need more force, we need to be stronger right now doing this thing, You will recruit more muscle fibers as your brain sends these strongers and stronger signal. And the fibers are not recruited separately. They're recruited from the smallest ones all the way up to the largest ones. But when the largest ones are being used, all of the smaller ones below that are also being used. Now, that is right there is the size principle. about the size principle is that most people cannot actually access 100% of their motor units available because their brain can't send a signal. And we don't know why exactly. It might just be a protective mechanism because there's a high likelihood that you could tear your muscle off of the tendon and the bone. It doesn't matter because most people cannot access all of their muscle fibers. So this is actually one of the things that I wanted to point out about the Type IIx to Type IIa conversion before is that a lot of the Type IIx fibers were probably in their very largest motor units that these cyclists had that you are probably not accessing while you are on a bike because the force requirements are not quite that high. And one of the reasons that you can't access these large motor units is in neural drive. which can actually be trained. And in this study, because we don't see additional contractile elements being built, Type IIx fibers produce more force than Type IIa fibers. So on paper, just looking at the muscle, and that they didn't build any extra and that they were still getting stronger and that they had less strongly contracting muscle fiber types. We would not think that they got stronger, but they did because they were training their neural drive to access more motor units. Okay, and in the heavy lifting for strength, like in this study, the short reps means low fatigue and this means high neural drive to your motor units when you are lifting. and yes neural drive fatigues like if you don't get enough sleep it's going to it's going to fatigue you're not going to be able to recruit those big muscle fibers stuff like that and of course as you exercise it also fatigues and so one of the things that these cyclists in the study in the strength endurance group were training one of the big things here is more neural drive and more fatigue resistance of the neural drive But one of the things that goes into, yeah, being rested and tapered and things like that is this neural component. Yeah, precisely. And okay, so how does the size principle work when you're on a bike if, you know, because we've just been talking about it so far with maximal strength applications. So when you start riding a bike, you are initially recruiting small, slow-twitch Motor Units. And these, okay, and as they are used to pedal the bike, they start using fuel, which is to say glucose and glycogen and fat, of course. But... As the glycogen depletes, as you pedal longer or possibly pedaling harder, your glycogen stores start to diminish and now your smallest motor units cannot meet the forced demands anymore of pedaling a bike at, you know, like 150, 200 newtons or whatever it is. So what happens is you start recruiting larger motor units with fresh glycogen stores. And one of the things to note about this study is that these cyclists actually have a huge proportion of Type I fibers. So they're actually about 70% Type I. And one of the things to note about this is that like you can get into fairly large motor units and they are still very efficient with oxygen type motor units. So that is one of the things that gives a lot of cyclists really good endurance is this huge amount of Type I fibers. And so when you start training and as your smaller motor units fatigue and you start recruiting larger motor units, these will adapt to the endurance training. And the endurance training being a sustained demand for ATP because that's exactly what endurance is. One of the reasons that good endurance athletes have a lot of slow-twitch fibers is because the body would prefer to have well-trained slow-twitch fibers because they're more efficient at producing ATP and they can do it for longer. They are more fatigue resistant. We're getting a little ahead of ourselves in terms of fiber type, but it's so important to understand about. Good Endurance Cyclists. Also, one of the really cool things about well-trained endurance cyclists is that they actually use in like an FTP effort, for instance, they will actually use 20 to 25% more of their muscle fibers and muscle mass than untrained people, which is a, the first time I read it was a startling statistic until I remembered. All right, Size Principle. They're probably used to recruiting larger motor units and they have more, you know, they have better fatigue resistance of their neural drive to do so. I think the other comparison you could think like, you know, if you're, if you're a untrained person off the couch, you've never actually done enough work for your body to think, oh, I should like turn on those larger motor units that have this higher threshold for being Activated Mentally. Like, if you sit on the couch, you eat donuts all the time. It's stressful mentally sometimes as not getting donuts as it can be. It's just not actually forcing your body to dig that deep to look for these larger motor units. Here's the big question. This is the whole enchilada. So how does this explain the 45-minute time trial power going up? with all the other endurance-related factors, VO2 max and FTP and Type I fiber type staying the same. So what happened during the test was the neural drive of the strength-trained group was greater, giving them access to a larger number of motor units than the just endurance-trained group had access to. This also means that they had access to more glycogen stores. Literally, they had more energy available. So we actually see the same effects in a lot of other studies with similar training modalities are shown to increase the fatigue resistance of the neural drive during submaximal exercise. And this is especially common at intensities above FTP and also below VO2 max. So as mentioned, the 45-minute test for these athletes is between the VO2max and FTP. And so as your brain gets trained to put out a stronger signal for longer, and we know that this happened because of the reasons that we outlined above, like they didn't grow any more muscle mass, but they still got stronger, et cetera, et cetera. All right, so the new oxidative Type IIa fibers took the place of Type IIx fibers, which were probably in the very largest of motor units. So in the five-minute test, when these more oxidative motor units might have been accessed, we probably didn't see the five-minute test power go up because power output for a five-minute test is probably limited by VO2 max and a couple other things. And so that would probably limit... you know your ability to put out power despite your ability to access more muscle fibers like you've only got so much oxygen to go around at that point you know what I mean okay and so okay so with the five-minute test the last the last bit is that this and a couple other studies I've seen actually disprove a theory that I've seen in a couple places among strength and conditioning professionals you know papers and literature and whatnot is that They theorized that greater motor unit recruitment increases muscle tissue demand for oxygen and therefore will increase VO2 max by being able to create more demand for oxygen and therefore extract more oxygen out of the bloodstream. But at least in the elite population, you know, we'll probably not see an effect because, you know, As stated before, the heart and lungs and your ability to actually get oxygen in is probably going to be your limiting factor at something like that. Yeah. I think it's also, that one's always been a strange theory to me because then you'd think you would see really great VO2 max numbers from like elite IFBB pro bodybuilders or something. And you're like, well, no, they don't train the other components. Aerobic respiration. Yeah, yeah. Okay, actually, it's funny that you say IFBB Pro because one of the best examples that I can think of to illustrate what's going on, like in the 45-minute test here, is actually bodybuilder style weightlifting where you're doing, you know, 12 to 15 reps with short rests. and what happens is your first rep, you know, it's pretty quick and then your last rep, you are absolutely grinding it out and this is because you are recruiting larger motor units as the smaller ones fatigue and you are also limited as you do these reps by your neural drive because as you do these reps You're sending a signal, I need these muscle fibers for this force demand. I need more, I need more, I need more every single rep until you get to, you know, your neural drive has come down to such a limit where you can only get so many muscle fibers to recruit. And now you are at the very largest muscle fibers that you could possibly recruit and your smallest ones. are absolutely knackered. So that's why your last rep looks so slow. Even though it's much less than your one rep max, it still looks like that's the most force that you can produce because that's the most force you can produce. One of the things to think about here is what is limiting your ability to put out power at different effort levels. So, you know, sprinting is limited by certain factors, you know, one minute-ish power is limited by certain factors, five minute power is limited by certain factors like VO2max, you know, FTP is limited by certain factors, you know, there's a limit to different factors, and here between VO2max and FTP is a very unique range where your neural drive is actually a very large factor in how many muscle fibers that you can recruit and use. But, as always, this is not a blanket. You absolutely have to go into the gym and grab a barbell and start lifting heavy right now because that is absolutely not the case. I usually only have my roadies in the gym for one to three months in the winter and that's it. and they generally don't lift nearly as much as this group and we generally do it for other reasons because as I said before there are certainly ways to get this kind of adaptation of neural drive on the bike they're a bit of a trade secret so I'm not going to go into too much detail however I will say that this is neither a recommendation or anything like that What I really want to do with the podcast, as always, is show people how training works. And sometimes I'll talk about my experience in coaching people, but for the most part, I think that people having the tools and the understanding of why things work is the most crucial thing in developing proper training plans and understanding what's really going on in your body. And is that a... a phenomenon that we can expect to see in lots of people or almost everyone or your other potential cyclists who are interested in incorporating strength training into their season or their annual planning. In most individuals who are racing and doing hard efforts and stuff like that, I would probably say that the effect is going to be seen slightly but not as dramatically as in the study. And in very highly trained people I would say that this effect is not going to be found at all. And I would say it's certainly different individual to individual. because I've seen a lot of people who have done strength training and none of the power over threshold has gone up. But I've also seen people, including myself, who start doing strength training and suddenly your over threshold watts just explode. Yeah, so I think, and as you kind of mentioned before, if you have a history with strength training, you may already have access to some of that. Additional Neural Drive, and so you may actually see this less than if you have this, if you're a total noob to strength training and you've never picked up a barbell ever, then maybe you are going to actually find yourself being able to generate a little bit more neural drive. Yeah, and this is definitely something that I think about when I'm training people, especially when I'm developing athletes who I know I'm going to be working with for a long time who have lofty ambitions. When I train, Even during regular weekly training, I'm always thinking that long term, and this is actually one of the things that I do consider, and it does affect the day-to-day workouts. I guess one of the big take-homes from this is that you only train the muscle fibers that you recruit. That kind of sounds like it would be obvious, but I think it's probably something good to hear, maybe for the first time, or maybe Ad Nauseam, but yeah, if you're not actually going to use part of your muscle fibers, like you can think of this in the really dumb example is, well, if you never work your upper body because you're a climber and you don't need that extra mass weighing you down, well, you're not going to be training your arms. Well, I think that's a little bit of a A funny thing to some people is to think about, you know, anytime you flex a muscle, like, you know, you flex your quad, you know, it's like, are you using all of your muscle? And the answer is, it depends on how hard you flex it. That, you know, you can flex a muscle and not be using all of your muscle. Because it feels like you're using all of your muscle. Intuitively, you know, you are using all of your muscle, but in reality, you are really not. Well, your body is trying to, you know, be just as lazy as you are at heart and conserve as much energy and fuel as possible. So if you're only thinking like, ah, you know, flex what little bicep I have to try and, you know, pose for a bad Tinder photo or whatever, your body's not too worried about that. Yeah, and so also remember that your body only recruits muscle fibers to meet the force demands. Like at the end of a race and you're pedaling squares and you are, and you feel like you're pedaling as absolutely hard as you can, you know, you are, you are at the point where your body is trying to recruit larger motor units, but now you are, you are neurally too tired to send a signal strong enough to get to them. So now all you have is like, you know, three quarters or like four fifths or, you know, whatever it is. of your sad, empty muscle fibers left, just trying to push the pedals to the finish line. Alright, as always, I want to thank everybody for listening. 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