35 Isometrics

Hello and welcome to the High Performance Physiology Podcast. I'm Chris Beardsley. I'm here with my co-host Rob Mouseri. And we're going to talk about isometrics today. So basically, I'm going to give a quick intro into how isometrics work physiologically. And then I'm going to hand over to Rob and he's going to talk a little bit about how he programs isometrics for the purposes of increasing motor unit recruitment. And what kind of other training methods that can replace and then I'm going to ask him a little bit about how he uses them for other purposes, for example, increasing tendons stiffness or what have you. And then we'll talk a bit about the kind of misunderstandings that are common in the industry at the moment regarding how to use usometrics and what they do and kind of all that kind of thing. Now, before we get started, I'm going to apologise in advance. We've got some connection issues. So we are going to be probably talking over each other a little bit. So apologies if that is disturbing. But we're going to do the best we can. And hopefully to WU guys, interesting kind of insight into isometrics and how they work. So starting at the beginning, isometrics are very, very similar to heavy strength training in many respects. Physiologically, if you have a high level of effort and you haven't got that effort being caused by, you know, sort of discomforting sensations like, you know, the burning in the muscle or the cardiovascular discomfort of breathing hard. If you've got a high effort, then you can have a high recruitment. So if you're doing a niceometric and you've got a high level of effort while you're doing the high isometric, and generally speaking, you're going to have a reasonably high level of motine, you can have a lot of muscle fibres being activated. Now, as I say, if you got there by, if you got to that level of higher effort by, you know, feeling, you know, really out of breath or burning in the muscle or anything else like that, then you're going to have to kind of discount the level of recruitment you're really achieving for those negative sensations. But, you know, if you just go straight in, you know, ramp up over a couple of seconds to a high level of effort, then you really should be getting a high level of recruitment as a result of that. Similarly, if you are looking at their muscle, then obviously muscle fibres, mechanical tension is determined by the force velocity relationship. So obviously, isometrics are pretty static. So the zero velocity, which is very, very slow. So in that respect, they function very much like heavy strength training does. You've got a slow movement velocity the whole time. You are going to get a hypertrophic stimulus from isometrics. Now, I know that a lot of people kind of think that strength training is kind of magical and, you know, therefore, if it doesn't look like a dynamic heavy strength training exercise, then it won't do what a dynamic strength training exercise does. But the reality is that isometrics and heavy dynamics are pretty much the same thing as far as the muscle fibres are concerned. If they are moving or if they're not moving, it doesn't really matter. As long as the velocity is slow or in fact zero, then you're going to get a high level of mechanical tension. Okay. So broadly speaking, isometrics and heavy dynamics are very, very similar in many respects, both from the neural point of view and also from the peripheral point of view. Regarding the tendon, again, tendons really don't care as long as they're just recognized stress and strain. And you can get that from isometrics the same way as getting it for dynamics, very, very little difference. There are some subtle differences that I want to point out. In terms of fatigue, we get a little bit more spinal CNS fatigue with isometrics. I don't talk about spinal CNS fatigue very much with heavy strength training because generally speaking, it doesn't create much of an issue, but it does create an issue with isometrics if they go on too long. We'll pick up on that later on. Basically, spinal CNS fatigue just accumulates over time with the sustained contraction that we're doing. So if we do a contraction, it takes two or three seconds and then we do an eccentric and obviously bring the weight back to the beginning and then do another kind of concentric phase, then we're kind of getting a reset to a degree on our spinal CNS fatigue every single rep. Similarly, if we take a short moment of pause between repetitions, we get the same thing. With isometrics, we generally don't get any of that. And as a result, spinal CNS fatigue can build to quite high levels rather to quickly, and that can reduce recruitment at the muscular level, which is obviously going to reduce activation, reduce the number 5 as being exposed to hypertrophic stimulus. So there is a kind of a difference in terms of fatigue. There's also a difference in terms of the way that fatigue mechanisms develop because generally speaking isometrics are more efficient in terms of peripheral fatigue mechanisms. So you're going to get a lot less metabolite accumulation, a lot less calciumine accumulation, obviously, unless you're working in stretch position isometrics than you might get more. But generally speaking, an isometric isn't going to develop peripheral fatigue mechanisms to the same rate at the same rate as a dynamic will do. So really, both of those things together or all of those things together tend to push us towards seeing spinal CNS fatigue as being a much more dominant fatigue mechanism in the context of isometrics, which what that means is that you'll still feel like you're putting in a lot of effort. It's just that the fibres aren't actually activating at the muscle end. So there's not really very much happening from a peripheral point of view. If you just keep the isometric in place. In terms of, as I say tendons, there's a small difference there because you get less kind of strain and recoil. You do get strain with isometrics on tendons. The tendons will kind of strain to a degree, but they won't strain them recoil and then strain them recoil and then strain them recoil. So you tend to end up with less tendon kind of micro damage with isometrics than you would do with dynamics. So there is a subtle difference there, and I think that's one of the reasons why they're so attractive from a tendon stiffness point of view. If you're using isometrics to develop tendon stiffness, you will get less damage to the tendon in that sort of scenario. As a result, you kind of come out ahead if you're using them as a protective mechanism to avoid tendon damage and kind of tendon pathologies. So really in practice, what I think that means is we've got a couple of interesting ways we can use isometrics. We can basically use them for enhancing recruitment because they instantaneously hit high levels of recruitment as soon as you kind of put a high effort in. And so that gives us the possibility of developing recruitment as an adaption, and I think that's probably one of the most interesting applications. Technically, you could use them for hypertrophy. I don't tend to do that very much. I think they're a little bit kind of fit for that, but absolutely, you know, physiologically it works. We've got a ton of data in exercise science showing that isometrics do produce hypertrophy in a number of different muscles and a number of different populations. So, you know, it's not like there's any kind of doubt on that particular score. Anybody saying that isometrics don't produce hypertrophy just hasn't looked at the studies that show that it does. So there's that, and then tendon stiffness obviously, as I say, it's a really nice data showing that that is a useful way for isometrics to include in the training program. So generally speaking, there's a lot we can do. What can't we do? We can't produce any high velocity related adaptions because obviously they're not really moving very quickly. So you don't get any of the firing frequency stuff or the, you know, kind of high velocity antagonist correctivation or anything like that. So generally speaking, if we want to develop speed, we can't really use isometrics. East-entry strength, I think, is tough as well to develop with isometrics. I think that probably doesn't kind of happen. Soch mode genesis is an interesting one, whether it actually happens with an isometric at long muscle length. I suspect it probably does, but that isn't really kind of predicted by our current models of how Titan works in the context of producing soch mode genesis. So it's an interesting area for future research, I think. We're broadly speaking, you know, generally speaking, the isometrics will do most of what heavy strength training will do. Obviously, the coordination of a heavy multi-joint lift, like a squat or a bench press or deadlift isn't going to happen from doing isometrics. So, you know, that's one of the things we talked about in our powerlifting podcasts when we talked about whether it's better to use isometrics and single joint or multi-joint in the context of improving powerlifting, kind of lift ability. So I've deliberately given quite a long intro there because of the connection issues that we're predicting to happen, but hopefully Rob is still there on the other end of the line, so I can hear you talking, so I think he probably is. So Rob, before the connection drops out, tell me about how you use isometrics for the purposes of increasing motine at a crewman. Give us the whole thing. Tell us where you put them in the workout, tell us, you know, kind of how many you do and what you do them for and all that kind of thing. Yes, so isometrics for the purpose of increasing recruitment has, you know, definitely got to be one of my favorite things to use over the last few years, and typically in a program, I'm going to place them at the start, but after the maximum speed work, so we'll do, you know, temperature-based warm-up, we'll do whatever jumps, throws, you know, et cetera, we might be doing for the day, and then any muscle that I'm interested in increasing recruitment and then after that, I'll place it right there, and then usually I'm just doing, you know, a few, like maybe one, two, three, the very most maximum intent isometrics for just a few seconds, usually anywhere from like three to five seconds, a lot of times using them for, you know, things like the hip flexors. One of the things we talked about in the sprinting podcast and in some others was using some isometrics in different positions, like a more extended versus a more flexed hip to target either the rectus femoris or some of the cell-as muscles. In the case of parylifters, I think we mentioned it in that podcast using some single joints. single and knee extension isometrics at the start for increasing recruitment in the quads, another case you can use for packs, like a single arm, pet fly isometric for increasing pet recruitment for bench press and things like that. So those are probably three of my top ways that I currently use them for a lot of the athletes I'm working with. Cool, awesome. So let me just expand on those points a little bit. So just to clear up any misunderstandings for people. We're talking about doing two or three maximum effort isometrics, lasting three to five seconds. Most of that what you described is single joint stuff, I'm guessing probably single limb as well. A stable, very stable context to maximize the ability to hit higher recruitment. In the context of the hip flexor example you gave, you gave two specific kind of muscles that were targeting wreck fem. So as you'd be hitting different joint tangles for that. So that's, I mean that's that's kind of really interesting one because you basically get two isometrics for the same kind of joint, but you're kind of targeting two different muscles according to the neuro mechanical matching telling us which muscle is working at which joint angle. Cool, awesome. So they're going between the high velocity section of the workout, which we need maximum kind of minimum fatigue and kind of maximum motivation for, but we still want the high motivation to be able to hit the higher recruitment levels in these kind of isometrics. So put them straight up to the high velocity section before we go into the heavy strength training section. Cool, awesome. So if you are doing then isometrics for the purpose of say for example, somebody's had a history of ten endopathy and they want to make sure a key is ten endopathy, let's say you've got a distance run out of course because most of them have got some history of or some experience with with with Achilles ten endopathy or they know someone who's had it and they're worried about it. So they've asked you to help them with their training program and you put some isometrics in there for calves. How would you approach doing that and how would it differ from the recruitment kind of focused approach? Yeah, so if I'm using them for tendent stiffness increases, you know, a lot of the times I'm not going to place them in the early portion of the workout because you don't need to be hitting, you know, maximum recruitment levels and that to be triggering tendent stiffness changes. So I'll definitely put them more towards the end, you know, probably towards the end of the heavy strength training section. And instead of doing, you know, just maybe like one or two or maybe three very brief contractions, you know, I might do, you know, three or four sets of a few contractions that are maybe like five seconds long max effort. And in the context of, you know, like increasing, say, the Achilles tendent stiffness for a runner like that, using like a bottom of the range of motion, you know, bottom half. So from a full stretch position and then come up, you know, just a bit and hold in that position for, you know, five seconds or so, trying to get as heavy a load as possible, you know, generally not going for things. If, you know, I'm trying to increase tendent stiffness, I'm not going to use something that's towards like a contracted position, you know, especially for the Achilles, I'm not going to use like a seated calf raise isometric or, you know, holding at the top of the range of motion because you just won't get nearly as much tendent stress you'll end on nearly as much load with something like that. Okay, awesome. So, so just to be clear, then you're doing a little bit more volume on those five, so the isometric's are longer, you're putting them later on in the workout. You're doing a little bit more volume, I guess. Yeah, I just a bit more volume. Like I said, it'll be a, you know, a few sets of a few contractions that are all, you know, each contractions about, you know, five seconds or so. Understood, cool. So, that obviously isn't, you know, so, so dramatically different as to be, kind of, you know, completely, completely apart from the maximum effort for the isometrics, but there is a subtle difference, I think, is worth pointing out. And I guess you would use them as well for kind of knee extension isometrics if you've got kind of volleyball players. Yeah, yeah, I have used them. I mean, I don't use them quite as often. Sometimes with the knee extension isometrics, I will go a little bit longer duration, but still not, you know, as we'll get into it in a minute. You know, I'm not going like typically 45, 60 seconds, anything like that. I do see a lot of talk about needing, you know, those very long durations for tendent stiffness. And like you said, you're going to get a lot of spinal CNS fatigue there. And you're going to feel like you're doing a lot and giving a high effort, but you're really not getting as much loading, especially if you do more than one, you know, one set or, you know, multiple reps of those things. Yeah, absolutely. I mean, in any isometric that goes, I mean, just to context, a strength training set, if we do it like a five rep max, then the concentric phase durations, if we add all of them up, we get to about sort of 12 to 15 seconds total. So, and that's kind of like an adventure press. You might get a little bit more, maybe 15 to 20 in a squat, but generally speaking, that's the kind of ballpark territory. So the reality is I think that any time we ever went over kind of 15 to 20 seconds for an isometric, you would be off the end of what is really kind of feasible to stimulate from a hypertrophic point of view. Attendance, you know, really are kind of agnostic about the way in which the muscle force is delivered. The tendon strain, I think repeating strain and recall is definitely something I would want to avoid. So, what I wouldn't want to do with 10, if I was trying to increase tendon stiffness, what I would not want to do is have, you know, kind of blipping on and off, like, one second on, one second off, one second off, one second off. I think that would probably be the opposite end of the scale, which wouldn't be very helpful, but I think a five second isometric is a great, is a great duration isometric. If somebody wanted to do 10 seconds, I'd be like, okay, I don't have a huge problem with that, but basically we can just batch them. I mean, we can do five seconds and take five seconds off or 10 seconds and take 10 seconds off. I think that kind of ballpark is probably okay for tendon stiffness changes. I wouldn't do anything not longer than five seconds for a motino recruitment increase because nothing's going to happen past that kind of four or five seconds point. But yeah, I mean, I think the idea that we'd want to go longer than that kind of 10 seconds, I mean, there's a difference between wanting a volume of time to reach the tendon and expose to that tension. I mean, fine, if you want to collect a minute's worth of, you know, tendon tension, you can do that in sort of, you know, six lots of 10 seconds or, you know, kind of 12 lots of five seconds. I mean, that's a lot. You don't need to do it in a, like, a minute sort of all in one go because the huge disadvantage of the, of the spinalcy has to be that you're accumulating, like you pointed out. Is that something that you're seeing a lot then? People talking about really long isometrics. Yeah. And I was in the combat sports world. Currently, there's a few guys that really push those. And like, you know, very, very, some of them are doing them for multiple minutes, which is just insane to me. And then some of the protocols I've seen are, you know, four reps of 60 seconds isometrics for, you know, multiple sets of those and things like that. And I, you know, from my perspective, those are not doing anything useful. I've never tried them myself, nor would I, you know, for myself, or for clients, I just don't really see the rationale when I hear people discuss them. You know, it's all kinds of things about shutting down your usual compensation patterns and then finally getting to a point where you're using the muscles you would like to use and all these kind of silly, you know, magical explanations. So things that really are just not happening. And then, you know, like we were just discussing, if you want, many useful tendon stiffness changes or things like that, you know, if you're doing a multiple minutes of an isometric, you're not getting any of that out of it. Yeah, wow. Okay. It's interesting, isn't it? How, when we talk about isometrics like we're doing today or when we talk about plyometrics like we've done in the past, our focus is always on quality and a high level of effort associated with the, with the high quality that we're trying to drive an adaption. So, you know, we're trying to achieve a particular goal and the way we do that is through quality and intensity. And when we talk about plyometrics, the kind of the, the prevailing kind of mode of doing plyometrics at the moment is to do an absolute ton of kind of low impact, low intensity bouncing around. And that's mirrored, really, by what you're telling me about these isometrics, people are kind of just doing a ton of long duration, relatively useless isometrics. So, we've got a lot of spinal CNSTG there, which again, you know, is going to have relatively minimal benefit in the same way that the low intensity plyometrics have relatively low benefit. So It comes back to this idea that a lot of the SNC community trends tend to be built around using volume and getting tired as a way to achieve a goal, but it doesn't achieve the goal. As a way to kind of, you know, I guess they believe that that somehow is going to achieve an adaption, and it kind of repeats. It's like the same thing that we see in bodybuilding where people do tons and tons of junk volume. Very strange. In terms of that coordination issue, really, when we are fatigued during exercise, the brain just carries on trying to do the same coordination pattern. It doesn't actually change it. What tends to happen in dynamic exercises is the output changes because the relative fatigue of different muscles is different, and as a result, you get a different output, but the actual inputs are the same. The brain really doesn't like changing stuff. If it has an idea of what a good movement pattern would look like, it would do that. And what the output then looks like can vary according to the relative fatigue at the muscular level. I don't think you would see much of that happening with an isometric to be honest. I think it would probably not really alter that much, but I certainly don't think it would see very much of a change. So I don't really understand where those kind of, as you say, magical ideas are coming from. But yeah, there we go. Anything else that's weird that you'll see? I mean, I'd just say one of the other ideas that I'd seen recently was that if you're using, you know, these longer durations, in fact, the protocol that I'd seen was the first week doing, you know, multiple reps of 40 second isometrics. The next week was multiple reps of 60 second isometrics in the time kept going up a little bit. And the coach explain it was trying to say that if you did those kinds of isometrics in the end range of motion, and actually, he was using like a deep split squat, unloaded as an example. He said you would also be getting sarcomyrogenesis and eccentric tolerance because of a long muscle length. And I'm just, you know, I see these things from, you know, fairly well-known coaches. And I'm, you know, I'm like, you're, you're just kind of making things up here. Like none of that is really going to happen from sitting in a bodyweight split squat for multiple reps of 60 to 70 seconds. Yeah. No, no, it's very, very strange. I mean, again, statements like eccentric tolerance. I mean, that's one of those kind of red flags for me when people start making stuff up. You know, it's not really a thing. Give me the name of the adaption and I'm listening. You can't tell me what the adaption is then, you know, the conversation comes to an end. Sarcomyrogenesis. I mean, I'm kind of, I mean, as you say, in a bodyweight scenario, sarcomyrogenesis is not really going to happen from a split squat position. I mean, honestly, at that point, you know, you would be saying, well, why don't you just do a static stretch and then you will get some sarcomyrogenesis and it'll happen across the entire team. You can hit on your engine motion. Of the muscle. Yeah. So it's kind of like people trying to change things into what they're not. I mean, you know, strength training is strength training, static stretching is static stretching. You know, don't try and blend them, you know, you can get something really interesting from both. You know, so, so do that. This whole kind of obsession with trying to turn strength training into, into stretching but loaded. I mean, it doesn't really work that well. You know, the two, the two things don't blend that easily. And eccentric are doing something different, really, and we've, you know, talked about those before. Cool. Okay. Well, I think we've probably done quite well given that we've got these really quite annoying connection issues. Did you have anything else that you wanted to address before we kind of cut and run today? You know, I think that's probably it. I'm hopeful you got most of what I said. I think I got most of what you said as well. So, you know, as a whole, hopefully the episode comes together. Okay. Yeah. I shall listen back to it and see how it went but fingers crossed, we, you know, kind of by blocking it, we probably got the messages across. So, yeah, hopefully that answers the questions that we've both been getting regarding how to use isometrics in the context of the strength training workout, kind of method that we've been describing, essentially putting them into the workout just after the high velocity section before they have a strength training. If we're focusing on increasing recruitment or putting it after the kind of strength training workout, strength training section before the plyometrics or ecentrics, if we're aiming for tendons, stiffness improvements. In terms of, I guess, some very, very brief, final comment, this really, I think isometrics can really do a lot to replace the power training that we tend to see being enormously common in essence. So, a lot of people are really, really still insisting on having power training as part of their workout plans, sometimes spending weeks and weeks and weeks on, you know, kind of Olympic weight lifting derivatives. And while those will improve motunit recruitment, there's not really a lot else they're actually going to do that transferable to sport. One of the really cool things about isometrics and Rob said this right at the beginning, you know, his favorite way is using them for increasing recruitment. Well, that's doing really what power training is doing, except it's doing it better because you've got very minimal coordination requirements. You can use much smaller amounts, a muscle mass, so you can get much higher recruitment levels, and you can really target precisely which muscle you want to create the recruitment gains in. So, I really just wanted to kind of close with that thought that I think we could use isometrics for a lot more than they're currently being used for and a lot more context. So, if you guys are listening to this, have ideas and you try it and you kind of feel that it's working for you, please do get in touch and let us know. We always like to hear feedback about how isometrics or anything else that we talk about can be used in practice, and obviously gives us more material that we can share with everybody else. So, that's everything from us today, we will be back next week with another topic.