Why is Kyle so negative about eccentrics?

Summary

In this episode, Kyle, Johnny, Zach, and Ben dive into the nuances of eccentric exercise, BFR, and muscle physiology. They explore myths, mechanisms, and practical applications for training and rehab.


Keywords

eccentric exercise, BFR, muscle damage, hypertrophy, physiology, training, rehab, muscle fibers, ECM, repeated bout effect


Key  topics

Eccentric exercise and its effects on muscle damage and hypertrophy
The role of blood flow restriction in training and rehab
Myths and misconceptions about eccentric exercise
Muscle fiber recruitment and the skeleton crew theory
Repeated bout effect and muscle resilience


Chapters

00:00 Reunion and Introduction of Topics
02:35 Exploring Eccentric Exercises and BFR
07:03 Understanding Eccentric vs. Concentric Exercises
14:41 The Science Behind Muscle Damage and Eccentrics
20:18 Understanding Eccentric Muscle Damage
22:44 The Repeated Bout Effect in Exercise
27:35 Mechanisms Behind Muscle Resilience
32:33 Eccentric Exercise and Load Context
36:32 BFR and Eccentric Training Synergy
42:21 Crossover Effects in Eccentric Training


Resources

Eccentric Exercise and Muscle Damage - Proske, U., & Morgan, D. L. (2001). Muscle damage from eccentric exercise: mechanism, mechanical signs, adaptation and clinical applications. J Physiol, 537(Pt 2), 333-345. doi:10.1111/j.1469-7793.2001.00333.x

Nuzzo, J. L., Pinto, M. D., Nosaka, K., & Steele, J. (2023). The eccentric:Concentric strength ratio of human skeletal muscle in vivo: Meta-analysis of the influences of sex, age, joint action, and velocity. Sports Med, 53(6), 1125-1136. doi:10.1007/s40279-023-01851-y

Lovering, R. M., & De Deyne, P. G. (2004). Contractile function, sarcolemma integrity, and the loss of dystrophin after skeletal muscle eccentric contraction-induced injury. Am J Physiol Cell Physiol, 286(2), C230-8. doi:10.1152/ajpcell.00199.2003

Behringer et al. (2017) — high-load eccentric BFR to failure; the volume-confound cautionary tale.

Jones et al. (2022) — eccentric hamstring BFR vs. high-load eccentric; 6-week crossover.

Sudo et al. (2015) — eccentric BFR via electrical stimulation, rat model; S6K1 signaling

https://owensrecoveryscience.com/

Transcript

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SPEAKER_05 0:24

Welcome to the Owens Recovery Science Podcast, where we dive deep into all things blood flow restriction training. I'm your show host, Johnny Owens, and whether you're a clinician, researcher, or athlete, you've come to the right place. Each episode we break down the latest research, interview leading experts, and translate complex science into practical applications. We're here to bridge the gap between laboratory findings and real-world implementation. I've got uh a special crew. The old crew is back. It's been so long they didn't know how to get their mics and their headphones to work, but finally these newbies have figured it out. So we have Zach and Ben back on the podcast with us, and Kyle. And this is I kind of like this podcast, Kyle. Kyle's like, hey, I've got a podcast I want to do. You guys don't prepare, don't worry about it. No agenda. Like, this is a freaking setup. This is a setup. Kyle's gonna be in his bonnet. He's gonna try and trick us on something.

SPEAKER_07 1:56

It's a trap. It is a trap.

SPEAKER_05 1:58

Let's do it on Monday after Father's Day, because you know, Johnny never passes up a party, so I'm already hungover from last night, and my brain's not working. Dude, it's sad, like any celebration, like my birthday, Father's Day, whatever, all my presents look the same. They're all like a little bag about the shape of a bottle. You guys get a little more creative. There might be a UT shirt thrown in on every now and then, but it's awesome. So, Kyle, you you freaking cook, man. Let's let's see what you got. I'm ready to shoot some bullets.

SPEAKER_02 2:34

Well, yeah, so something that I've been experiencing recently is a lot of people asking me about using eccentric exercise with BFR. Um, and in some cases, even just sort of the assumption from people that it would actually be better to do it in that manner, like the eccentric portion of the contraction would provide a better stimulus for hypertrophy and things like that. So um I just figured that might be a good kind of topic for us to talk about. There's a few different studies that have looked at combining BFR with eccentric exercise. Um, but I but it really for me kind of started from a place of, well, what do we even know about eccentric exercise? Like how much of the information that we hear is accurate, how much of it is lacking context, that sort of thing. So I mean, I'm just kind of curious from you guys have y'all had people you get people asking you that question about eccentric ex eccentric exercise, and how do you usually answer it?

SPEAKER_05 3:39

Dude, I submitted a whole freaking grant to the NFL with every Pac-12 team and every SEC team except for one on board. So maybe I'm one of those dumbasses that that's maybe why we didn't get the grant. But uh it was a thought. We made it to the finals, we were the last two. Oh, did you know, Kyle, that Dr. Feely was on the panel? Did I tell you that? No, I did not know that. He was on that panel. It was during you know COVID, so we had to do a Zoom panel, and he was one of the ones. I should have got on his ass on the podcast. We're rejecting. That's so funny. Yeah, they picked something new and novel instead to study eccentric exercise for hamstring injuries. Like, wow, no one's ever looked at that before. But yeah, anyways. So I mean, I've got thoughts. I look well like we know the Yesuda, you know, Jeremy's like a long time ago, concentric versus eccentric, concentric get better. But I don't get a ton of people asking. The Olympic team when I was out there for the runners we're talking about. That the runners really hate doing Nordics because it just makes their hamstrings feel tight for a long time. And you know, we can go into this. There is a potential for less muscle damage, maybe.

unknown 5:01

Yeah.

SPEAKER_05 5:01

If you do DFR, low load, eccentrics. So that was a thought. But I get more about BFR and isometrics. But what do I use that her band?

SPEAKER_00 5:10

Yeah, I mean, I I I would say it comes up maybe every now and then, not super frequent. Um, but I I think the the question or the answer to the question I'd always give is basically what are you looking to change or what do you what are you looking to target? And then that would be my kind of i is there benefit to it or or whatnot, and then what is the context of the individual you're working with? Um, and then that would also help to drive the answer.

SPEAKER_01 5:42

Yeah. I don't feel like I get the question all that often. You know, it comes up like Zach was saying every now and then. Uh, and it's I feel like it typically comes up around the idea of, you know, rehabbing tendon. You know, people will be like, oh, you know, I I know we're supposed to be doing eccentrics, so should I be doing eccentrics with my BFR? Is that better? And I tend to say I I think it really depends on how you're performing the exercise and how much weight you're able to actually load for the exercise as to, you know, is this something that we really need to have that much more focus on eccentric versus just performing an isotonic exercise and trying to get to fatigue? So um yeah. Limited conversations about it come up for me. So teach us up on eccentric sky.

SPEAKER_02 6:34

Yeah, so well that was kind of my next question is well, what do you guys I mean, what do you like think you know about them or what do you believe about them? Um because I suspect we all probably have learned a lot of the same shit um in school or heard it from people. Um, but like you know, when you think is eccentric exercise, um, you know, and you were asked to describe it to somebody, how would you how would you describe it?

SPEAKER_05 7:03

So I went to school in the 90s, bro, and we didn't learn physiology, we just learned modalities. Diathermy, ultrasound, this new thing called ESTEM. So but yeah. But the thing that was always with a BFR perspective is concentric, there's more metabolite accumulation. So you're probably getting a little more juice from the BFR side.

SPEAKER_02 7:34

Mm-hmm. When you're combining with concentric, you're saying.

SPEAKER_05 7:38

Mm-hmm.

unknown 7:38

Yeah.

SPEAKER_05 7:39

The metabolite accumulation, I mean, it's more mechanical tension on an eccentric lengthening, sarcomere damage versus concentric, we're getting a lot more of the metabolite accumulation, which is probably what why you sued us all they won. Even though maybe in that study were concentric speed eccentrics, they were underdosing the eccentrics.

SPEAKER_02 8:01

Yeah, I didn't remember.

SPEAKER_01 8:03

Main concepts that I remember are you know just the using it as an overload strategy, uh, being able to load heavier uh than you can typically control or manage concentrically. Definitely, you know, a lot of conversation around more muscle damage uh in that you know, eccentric form of exercise than just a traditional concentric or isotonic. Uh I know that I I don't like eccentrics from personal experience. That was always a common theme for me. It was uh a lot a lot of discomfort uh and typically some more soreness, likely because I'd hated to train it and didn't do it that often. So when I did it, it broke me off for a while. Um but yeah, a lot of the same things that Johnny mentioned.

unknown 8:54

Okay.

SPEAKER_04 8:55

Z? Yeah.

SPEAKER_05 8:57

Z is gonna be like, well, the possible relation of S6K.

SPEAKER_02 9:02

Cross-bridging is uh Yeah, I mean that's not what we're going for right now so much. So it's just like general beliefs, general thoughts that I have.

SPEAKER_00 9:11

I think my my opinion on eccentrics has changed recently or has evolved. Um I would say in uh in school and even early on since I was a PT, um people had this belief that eccentrics were superior, whether that be in terms of muscle or predominantly tendon. Um, but I think a lot of things have changed with that. Um I I think it was Johnny mentioned Nordics and and whatnot. And I think one of the things that we see with Nordics with eccentrics is that's really not the end-all be-all, and there's a lot of emerging evidence now that says that Nordics may not be as beneficial as we originally thought they were, um, largely as it relates to the specific muscles involved uh and and the action on the joint, um, the knee versus the hip. But yeah, I think things have changed with eccentrics and what really what I believe to be effective.

SPEAKER_04 10:16

Okay.

SPEAKER_02 10:18

Um let me see if these ring true with you. Just like I wrote down, I I've heard people say eccentrics prioritize like the recruitment of type two fibers. Have y'all heard that out there?

SPEAKER_05 10:34

Not until I read your agenda.

SPEAKER_00 10:37

Not till you not till you read my I mean I I think from a loading from yeah, i i if you look at it like you're you're going to basically be able to load the muscle more. So you would load an eccentric more. I would I would say that yeah, you would you could believe that. That can make some logical sense.

SPEAKER_02 10:58

Let me constrain that a little bit then, though. The the context of that statement, eccentrics recruit more type two, um, is irrespective of load. So it is saying, regardless of the load, you're gonna prioritize the recruitment of type two fibers. That's that's the context of that statement that's out there. If have y'all heard that, or do you go bullshit?

SPEAKER_07 11:25

I think bullshit.

SPEAKER_00 11:27

Okay. I I would because then you would just get yoked. Right. I mean, like if I just straighten my elbow, I I don't think I'm recruiting a ton of type two fibers, but yeah, right. Yeah. Drinking right.

SPEAKER_02 11:41

Right. Um, I've heard eccentric. So that's a myth, right? We missed that. No, I'm just saying, all I'm saying is these are the things that I have heard that I've heard out there in the ethos and talking to people and just like picking up stuff and looking at things. Like, this is what I or I read on Instagram when somebody provides some sort of an explanation, and I'm like, well, eccentric recruit more type 2 sure seems to lack a lot of context for me when I just think about it critically. But also, like, where the hell does that come from? Is sort of where my head goes too. Like, how why would people have that belief and that belief be repeated from multiple sources that are not, you know, related to one another in any way? So um, that's one that I have heard a number of times. I've also heard eccentrics cause more damage than concentric exercise, which you guys obviously context within load, but you know, it's you I I feel like you would echo that to a degree based on what you have said. Eccentrics are stronger, right? You're stronger eccentrically, right?

SPEAKER_07 12:58

Okay. 20 to 50 percent or something like that.

SPEAKER_02 13:02

Some somewhere in that neighborhood, yep. Those are the the main ones that I have heard, but I think it's I mean, you know, just I if there's anybody listening that doesn't know what an eccentric versus a concentric is, please stop listening. I know, yeah. Maybe maybe it's not the right podcast, but um it helps us sort of explain why there's potentially some thought behind you get a larger amount of exercise-induced muscle damage. You know, you have this sliding filament theory with with regard to how muscle contracts, the myosin head cross-bridges to the actin and pulls on it, and then that kind of kind of continues to happen. That's how you and basically when you do a concentric exercise, the muscle is shortening. Whereas when you perform an eccentric contraction, the muscle is lengthening. So those cross bridges are kind of breaking three free. But the thought is that um as that muscle is lengthening, those cross bridges are tearing off and damaging the muscle. And so that's where that muscle damage comes from. Um when I when I was kind of thinking about this, the one of the hard things that I had a really hard time reconciling for starters was well, how in the world could eccentric exercise cause more muscle damage, but I'm also 20 to 40 percent stronger with an eccentric exercise. Right? Because how does that how does that jive with a traditional isotonic exercise? That that proved created a problem for me logically. I'm like, that doesn't make sense. If I can lift this weight, why in the world would that same weight that I can lift concentrically cause damage eccentrically? So do you guys have you have you thought about it in that context, or do you understand why that happens, maybe?

SPEAKER_05 15:08

Well, the linking effect can play into it, but I've always thought it was the load. So you're gonna be doing more load eccentrically, and you're gonna get more muscle damage because the load would be higher than what you're able to the load, you just picked up the load.

SPEAKER_02 15:28

The load's the same as you picked up. It's an isotonic exercise. Is that true though?

SPEAKER_00 15:33

Well, I think the same load. I think what Johnny's saying is if you I think we're talking about maybe two different things, Kyle.

SPEAKER_02 15:43

You're you my context that I'm bringing up is the context of a one re prescribing exercise, as we traditionally do, based off of a one-repetition maximum. Right. And the eccentric portion of that exercise is what's causing the damage.

SPEAKER_01 16:06

Well, I think this is where the context is maybe lacking. Because I I know for me, when I thought of There's something missing.

SPEAKER_02 16:14

There has to be, right?

SPEAKER_01 16:16

When I thought of eccentrics causing more muscle damage, I was thinking of it in the context of how I was initially exposed to it, which is overloading an exercise to perform the eccentric portion of the movement with help for the concentric portion of the movement, because I couldn't do the concentric myself, right? Versus load matched or just, you know, doing an isotonic exercise that you can normally perform for a set number of reps and saying that the eccentric portion of that movement is somehow causing more damage than the concentric.

SPEAKER_02 16:51

So there, there, that's perfect. So you I mean yes, all of that. But the statement eccentrics cause more damage than concentric would be a statement that is made regardless of load. And I would argue that is believed, generally speaking. And what's interesting is has some physiologic foundation. So what I found was that like Johnny said earlier, metabolically, we see the cost of a concentric exercise being greater. Like there's more there's more work having to be done by the muscle. And we see you know things like um EMG being greater with uh the concentric portion versus the eccentric portion. And so what it looks like happens is once you begin to perform that eccentric exercise, and this is where that knowledge of like you heavily recruit type two, it looks like you use kind of a skeleton crew of muscle fiber to perform the eccentric action. So the amount of muscle you use to pick up the load then gets spread across less muscle fiber as you begin to lower it. And so that's where you might be performing a isotonic exercise, you know, let's say in accordance with ACSM guidelines, like we had for a long time, and we knew those loads caused increases in muscle size and muscle strength. And there's potential now for that load that you have been prescribed based off of an isotonic to actually cause more damage during the eccentric portion. So that's where that notion actually comes from. It's been shown to be accurate. So it's like this thing called the skeleton crew theory. And I think what's interesting is that kind of makes sense based on, you know, if we think about how we recruit muscle to perform an activity following Hinneman's size principle, we just recruit just enough, right? And it's type one first, and so and so and so on. But then we also know that type two fibers have a greater ability to produce force. And so now that once that load has been lifted, if all we have to do is set it down, it kind of makes sense from just like uh, you know, an evolutionary perspective, metabolic cost perspective, that it would behave in that manner that we might use less muscle to lower it down because we don't need to pick it up. Is that a concept that you guys had heard before?

SPEAKER_05 19:37

Well, yeah, and it's it's not just muscle. I mean it's the ECM and you know the the static structures.

SPEAKER_02 19:43

Well, but we're just talking about the the type of muscle contraction, though.

SPEAKER_05 19:46

Yeah, obviously there's gonna say 30 pounds, but 110 pound leg extensions. Single leg, yeah. Single leg.

SPEAKER_04 19:58

Mm-hmm.

SPEAKER_05 20:00

Concentrically, and then I work match it eccentrically, the muscle damage will be more just on the primarily on the eccentric side. Because I really always thought it was more load-based.

SPEAKER_02 20:15

We're we hold on.

SPEAKER_05 20:18

If it's the same load concentrically or eccentrically, there's studies that'll show you're gonna have more muscle damage with eccentrics. Correct. Up to up, but it has to be a threshold.

SPEAKER_02 20:29

I mean it below load is a good thing. And that's where that context piece comes in. Because at some point, that apps that makes zero sense, right? Like it doesn't make any sense at all that you could pick up a 30% load in the eccentric portion. To Zach's point earlier on, like we were just talking about extending his elbow or something like that. I'm obviously not causing a lot of muscle damage with that. But so at some point, the just the mechanical sort of structure of muscle, it has a threshold where that does not ring true. And it looks like that's probably around like that 50 to 65 percent load, which I think again kind of goes back to our sort of belief of how muscle used to adapt. We used to think you had to break it down, right? To and then repair it and build it back up. Um and you know, follows kind of along with our our ACSM guidelines, if you will. Right.

SPEAKER_07 21:26

Well, I'm glad ChatGPT taught you well, Kyle.

SPEAKER_04 21:29

Yeah.

SPEAKER_02 21:30

Chat GPT plus all the different papers that I have in my my paper pile and just asking it questions over and over and over. Because I'm just like, I don't understand how this how this really works, I don't think. Um, so then if we're talking muscle damage um and you know, exercise physiology, we obviously start thinking about DOMS. Um You know, just the delayed restoration of strength, those sorts of things. Um But we also have this thing called the repeated bounce effect, right? That sort of makes us more resilient to damage, if you will, or soreness at least, um after a even just like a second exposure to to exercise. So um I guess my question then would to you guys would be um how do you feel, like what's your understanding of how the like the repeated bounce effect sort of fits into you know this role with eccentric exercise. Like what have you learned, or you know, what do you what do you know? And we'll talk about maybe what what we think happens at least. Anyone? Zach?

SPEAKER_01 22:58

Let Zach take it this time. Well, you look like he was about to do that.

SPEAKER_00 23:01

With Nordics, it it's been shown that there's a repeated bout effect where uh initially there's a significant increase in whether it be muscle damage, however you measure that, assess that. It could, you know, you could use DOMs with that. Um, and then as that um your your protocol, your program that you're doing with Nordics, as that increases, there's less and less muscle soreness, muscle damage uh as the the deal goes on. Um and I always tell people this is really kind of where it ties in with uh your ACSM guidelines, where they're not just a load-dependent guideline, there's a duration-dependent guideline, and this is where we moved away from the idea that muscle damage is necessary to provoke a hypertrophy response because you're not you're not building muscle if you're constantly breaking muscle down, and then that protein synthetic response is directed towards repairing damaged muscle versus growing healthy muscle.

SPEAKER_05 24:05

So Yeah, and it's you know, with each exposure. That's why the first, you know, was it Stu Phillips stuff where it was like the muscle damage is just the cost. But eventually the the anabolic side starts to take over, and then you start to get hypertrophy and not just muscle fiber, but you know, you're getting collagen synthesis, which is working on the ECM and making those structures more resilient and strong over time. And in my mind, that's always what we got from the repeated bounce effect.

SPEAKER_00 24:37

Basically, it it be I think Kyle, you said it becomes more resilient. Um so you're able to tolerate.

SPEAKER_04 24:44

Yeah.

SPEAKER_02 24:45

Because just just literally one exposure can create a repeated bounce effect that lasts something like six months.

SPEAKER_01 24:55

I browsed over that exact paper that I'm pretty sure, you know, kind of kicked off this question, Kyle. Uh, they're talking about potentially up yeah, you lose it around nine months after the exposure.

SPEAKER_02 25:06

It's wild. It lasts for a very long time. How do they measure that? Yeah, that's all.

SPEAKER_01 25:13

That's uh good luck controlling that study.

SPEAKER_00 25:15

Yeah, I think it I think that would probably vary, you know. What are you looking at um individuals in that study, you know?

SPEAKER_01 25:27

I think they were primarily looking at indirect markers uh of damage after exposure to eccentrics. Yeah. That's the most common.

SPEAKER_02 25:35

But ultimately, the the point is that um just exposing one time really creates a very robust protective effect to a secondary exposure. Um now the and so the question then becomes well, what is it based on one paper? I mean, what is actually changed? No, I mean this is this is generally kind of accepted physiology that's out there. Um Steven Patterson repeated, spouted that very fact to me at CSM, what was it, six, seven years ago.

SPEAKER_01 26:04

He was like, Yeah, like you know, it's something crazy, like six months of protection you get from what I'm hearing there, Kyle, is that my current you know exposure that I'm giving myself to eccentrics of you know once or twice a year is 20, and I don't ever need to do more eccentrics than what I'm currently doing.

SPEAKER_02 26:26

Maybe I don't no, I don't think so. Um because we certainly know different things about well, it depends on what you're trying to accomplish.

SPEAKER_05 26:36

Man, like you would have done your one one bout. Your one your one bout. Okay, then what's the mechanism of that?

SPEAKER_02 26:45

Well, so uh I lost my train of thought.

SPEAKER_05 26:49

Dang it, I hate it when you're gonna know you weren't prepared for that. You gotta come back, no, just reading off.

SPEAKER_00 26:56

I've been working on this for we were talking about the repeated bout effect lasting six, nine months.

SPEAKER_02 27:01

Yeah, yeah, yeah, yeah. And I was like, why so okay, so this is where I was headed with that. Um, like mechanistically, the question then kind of becomes sort of like what happened? You know, what's going on there? Like, why would that be? And so for there were two general theories for a very long time. Um, and I would say that they're still kind of out there. Um, one is that you add longitudinally sarcomere to the sarcomere, the disruption of the Z-disc happens, and then you kind of add longitudinally there, and so the addition of sarcomerogenesis is what it's called, um, provides um protection. The second thought uh is that you get better at recruiting muscle, so there's some sort of neurophysiologic change that you recruit muscle in a different fashion. So that skeleton crew idea that I mentioned initially, where you're really just kind of going type two, now that shifts a little bit and you recruit a little bit more type one, and you're just a little bit better at doing that eccentric. And so now it just doesn't, it can't, the sheer effect of like pulling the mice and chain head off of the and ripping the cross bridges apart and damaging the muscle doesn't happen because you are spreading that out. The problem with that is you don't see increases in EMG through like a second, third exposure, whatever when you're performing the eccentric portion. Um and the idea that you would actually add like contractile elements after a single exposure, like when you think about that critically, doesn't make a whole lot of sense. And really, honestly, the recruitment of muscle, order you know, ordering that differently just through one exposure doesn't really seem to follow, I feel like what we see in physiology. It's like you've you've got to like repeatedly do things to convince the body to add muscle, to you, you know, to require more nutrients, et cetera, et cetera, to function. Um and so those things don't really follow, don't seem to add up. What'd you say? I said we're back to it's bullshit. Yeah, right. Well, I mean, I I think it's just important to me.

SPEAKER_05 29:20

Show me a mechanism, or I don't believe it.

SPEAKER_02 29:22

At least ask the question like, what the hell's going on here, you know? Um so that's where I think the this ECM seems to kind of make the most sense and kind of come into play. That likely, you know, over time you lose some of that the lateral force transmission components of the extracellular matrix. And, you know, now when you create that damage, that's the thing that you can kind of not only do you repair the damage to the muscle fiber, but you can sort of repair that extracellular matrix in a lot uh a lot quicker fashion. And what's wild is something like 80% of the load that you lift concentrically is spread laterally into the extracellular matrix. So I think that also, like when you think about it critically, that also sort of makes sense in terms of like how you're able to use less muscle and how you're able to be so much stronger eccentrically is because that muscle is already contracted, that force is already spread laterally, and now you start to load into an eccentric fashion, and and you've already kind of done all that work that typically you would do with a concentric exercise.

SPEAKER_05 30:34

Um the ECM's amazing. Like amazing. We worked with that a lot during the wars, and you can take the ECM and implant it into different tissues and it will grow those tissues. And this Marine who took a freaking RPG like explosion and took out his like almost his whole quad, he he couldn't generate any torque at all. And we were able to put the ECM into his muscle that was left, and it just created a giant collagen scar matrix. And the dude was able to generate like you know, almost 50% torque compared to his other limb after that collagen structure came back. So just some muscle, but a ton of ECM and and scar, let that guy be able to walk. Which is crazy. So when you're working out, you're not just working out muscle fiber, you're working out ECM as well. Yeah, all the movement.

SPEAKER_02 31:38

And I think that now I believe that theory starts to make it starts to make a little bit more sense in terms of like what we've learned and you know what you know people used to believe in sort of the context now of of where our knowledge is, um, things start to make a bit more sense. But I think, you know, we haven't really come outright and said it and talked about specifically, but you you cannot really just talk about eccentric exercise. You have to talk about eccentric exercise in the context of the load that's being lifted. We lost sack a bit there. Just let them log in. Um so you like Ben, when you talk eccentrics, you know, and you can clearly tell by the way you're talking about it that you are performing eccentric exercise with a load that you are unable to lift concentrically. It is an it is a load that we would have to base off of an eccentric maximum. Which is sort of where you know Johnny was kind of going with the NFL thing earlier. Like those loads were based off a super maximal physiologic load that they that they lifted in that study out of USC. They didn't lift a 30% of one repetition maximum load, they lifted a 30% load of the maximal amount of force they were able to produce eccentrically as measured with a Nordic exercise. Makes that context of that study understanding that really important. Because if you just look 30% one rep max load, which I think is how it's written, like when they're just kind of abbreviating in there, um, you think concentric, but it's actually not. It was probably more like a 60% load or something like that that they were actually doing each other.

SPEAKER_05 33:32

Todd got badass results too. Yeah.

SPEAKER_02 33:34

And they got great results. Yeah, they did.

SPEAKER_05 33:36

And he was on my panel, he was my co-author on this grant. Yeah.

SPEAKER_01 33:41

The thing that I I'd like to go back to that paper for, and it might be there, I'm not sure, is is what is the uh perceptual side of that, because the idea of the volume of reps that they did at that intensity, with that, you know, that's a lot of eccentric volume that they did. And at an 80% pressure, which that alone for hamstring isolated stuff is also pretty rough. I mean, I could see it being significantly effective, and especially compared to like Johnny brought up the Yasuda paper earlier, you know, 30% of a concentric max when done with an eccentric biased, you know, movement comparing to concentric, it's you know, didn't really do anything. It wasn't enough.

SPEAKER_05 34:28

And so there's the uh pseudo, what is it? The it's a mouse study, I think. The mouse study. Yep. Yeah. So a a high eccentric load without BFR, there's a lot of muscle damage. And when they put the cuff on, almost no muscle damage. So it it might suck when you're doing it, but what really sucks about eccentrics is day two, three, four. And that's what Todd was saying is like these guys were like they actually were preferring the BFR because they weren't as sore.

SPEAKER_02 34:59

You know, that that pseudopaper, um for for listeners, the pseudopaper is uh is a rat study or a mouse? I think it's a rat study, um, where they induce a maximal contraction via neuromuscular stem. And then they had this dynamometer that just like broke these little rats off into like knee flexion or whatever it was. And so what's wild about the type of muscle damage that's caused there is it's like instead of where like normally in humans, if you biopsy, it's like little dents and chunks kind of taken out of the muscle. As I understand it and reading that paper, like the the muscle damage is like the length of the fiber.

SPEAKER_05 35:47

So it's it's like crazy worse than like the normal muscle damage a little rational like, damn man, I don't know what they did to me while I was asleep, but I can hardly walk right now. Yeah, exactly. Exactly. Well, so we need to get to then what are your thoughts? Well, I'm not trying to hijack your your podcast out, but then what are your thoughts on should you do BFR with eccentrics? Because our whole point, obviously, after Todd's work, and you know, we had all this other stuff in there, the pseudo paper, and you know, I forgot. Maybe it was the one where they did low load to failure and low load with BFR eccentrics, and it was again they similar results, but a third of the work. And so for an injured population, this all seemed really good.

SPEAKER_02 36:41

Yeah, I think, you know, that um I think the way you guys did eccentrics is just different than traditional BFR, you know, and you could even maybe look at it as like a progression potentially. Um, you know, maybe you start with a traditional isotonic where you're using a 30% concentric load with BFR, and then you maybe progress to this sort of supra physiologic load, um, or more or a load just more based off of an eccentric maximum than a concentric maximum.

SPEAKER_05 37:16

Well, what I thought we did, it was slick. Um, because it was with in a team setting and they were all going to be getting strength testing. We got pre-injury baseline eccentric one RM. And even though they might change during the season, we had a we had a ballpark of each player when they got because we we definitely couldn't test it after a hamstring injury, but we knew what it was, so we had a target to go after. Yeah. Not everyone can do that, but if you're in a team setting, that's one way. If you're like, well, for my guys that are gonna pull a hammy, I could do this BFR in the early phase and get basically what Todd showed, everything was equal to lifting heavy eccentrically, and less muscle damage.

unknown 37:59

Yeah.

SPEAKER_05 37:59

And maybe some some analgesia.

SPEAKER_01 38:02

Yeah, it this is one of those places where I tend to think it's you absolutely can do BFR with an eccentric focus, as long as, like we talked about, the context and the parameters are appropriate. You know, I tend to think what most people are doing with BFR is probably light enough that maybe the eccentric focus is not going to do what we intend it to. Uh, and that's where, you know, I tend to, you know, when the conversation comes up, that's one of the main points that I make is like, you know, are you really going to be doing enough that the eccentric focus is going to make a difference? Or should we just be doing our isotonic exercise to fatigue? And then as you can tolerate more load, let's let's go push some loading. And then again, you know, from an eccentric standpoint, are we talking about you know heavier load? Are we talking about something with some speed? What you know, what is the what is the goal and what's available uh to dictate if we should be doing it with BFR?

SPEAKER_05 39:05

Yeah. I think the key point out of all this was if you're doing eccentric with BFR, you're not in a 20, 30 percent 1 RM to probably move that needle. Yeah.

SPEAKER_02 39:17

Yeah, exactly. That's the problem. There's nothing. And if it's eccentrics, it needs to be a percentage of an eccentric one rep max. And just to kind of, you know, maybe further support that. I don't know if y'all saw the Behringer study, but um, I like that paper because it's a knee extension exercise at a 75% of one rep max with and without BFR. Um the BFR is like 20 millimeters of mercury below AOP, so it's a pretty high um pressure. But you can see the control group does could do like 142 repetitions at that load without BFR. You add BFR, and now 85 reps was the max. So you still see an acceleration of fatigue, but it's it's not as quick as if you were doing an isotonic exercise. Like a heavy load, like a 75% load, and they're still doing 85 reps at a 75% load with at least 80% pressure somewhere in there. So we see an acceleration.

SPEAKER_05 40:38

Did they measure I think that's what I was talking about? They got there in a third of the time or whatever, but did they measure muscle damage or DOMs or anything?

SPEAKER_02 40:47

Um let me see, I forget. Yeah, they just measure soreness, range of motion, that kind of thing, uh CK, and didn't see any differences between the groups. Not different.

SPEAKER_00 40:59

Yeah.

SPEAKER_02 41:00

So despite the despite the volume differences, even. So that was one of the thoughts on that paper was well, maybe because the BFR group did less volume, uh, they didn't they didn't see that. Um, but you know, the the pseudo paper might suggest that, hey, there's actually protective effect of the addition of BFR here.

SPEAKER_01 41:21

So yet another case of BFR isn't magic and it doesn't fix exercise prescription. It doesn't fix your crappy exercise prescription.

SPEAKER_05 41:32

Yeah. But if you prescribe it right, there could be a play with these centrics. And by the way, if any funding mechanisms are listening to this podcast, we still have that grant proposal. We are happy to have it. Ready to go. Even though study the Pac-12 isn't really a thing anymore. We'd have to do some more teams, but yeah, it's really not.

SPEAKER_02 41:55

It's really not. Um I did want to like just kind of highlight one other study, not because it's a great uh it's a fine study. It's just not really gonna support one way or another what we discussed, but important again, context. So there's I don't know if y'all saw the Hill, Dr. Hill's paper, um, where they did they did a bicep curl, um, but then they measured the non-exercising side. So they did um a concentric one rep max. Um I'm sorry, no, it was isokinetic, but um eccentric versus concentric with BFR, and then looked to see was there like a crossover effect, and they only saw the crossover effect happen in their eccentric group. Um I I would say that my my the reason I say I wanted to discuss that was because that study shouldn't be used to support hey, BFR creates a crossover effect, because like when you look at let's just load this heavy for a crossover effect, you see a greater effect or at least the same magnitude of effect. So it there's no reason to do BFR, just load that heavy if you can to create that crossover effect.

SPEAKER_01 43:12

And that was always Steve Patterson's point that he made on you know cross-transfer, crossover. It's like we know a lot more about heavy load, so why not do the heavy versus trying to say BFR is the thing that's gonna give it to you? Stevie Boy getting multiple shout-outs on this.

SPEAKER_05 43:30

That means I learned everything about a day. It's been a minute. I guess we need to get them back on. Yeah. Well, and then I guess lastly, another way to just think about your eccentrics was talking about another Eurofriend Alex's eccentric IPC paper. And so do an IPC prior to heavy eccentrics, significantly less muscle damage and soreness. So if you hate and then maybe you should be IPC in before you do your once a year, you know. Protect you for nine months apparently. E-centric work. But yeah, IPC prior, if you're athletes hated, there is at least a study from Alex that showed significantly took down the muscle damage.

SPEAKER_02 44:12

And that just goes to show you that all of these things are so multifactorial, you know, like we oh, there's so many different theories as to why there's this protective effect. Um and then multiple reasons that we can either prove or disprove. And then you have something like that where it's like, well, that that could have nothing to do with the lateral force transmission, the protective effect that IPC might provide. So there's clearly more going on than you know just a simple.

SPEAKER_05 44:47

And there's just there's just such big variants sometimes, and when they're like, Well, we didn't see a change, like, well, forty percent might not be enough.

SPEAKER_02 44:55

All right. Appreciate y'all.

SPEAKER_05 44:59

I like this, man. I like this. I didn't have to prepare hardly at all. Yeah. Uh uh I think that's a good way to do it, you know. If anyone's gonna be a NATA, Ben will be out there. Um this podcast might come out right before he goes. We have courses all over the place. Focus, BFR with throwing, it's blowing up. So people check out our website and get some courses. And like our freaking podcast, man. We haven't got any likes in a long time.

SPEAKER_02 45:28

Is anybody actually listening?

SPEAKER_05 45:29

Is he still here? Yeah, he's still there. What helped if we actually keep them coming out regularly, which we're working on, we have a ton of badass guests coming out. So if you didn't learn, here are our last two podcasts that are really good. The one with Dr. Feely, man.

SPEAKER_07 45:42

Learned learned some cool shit last week. Two weeks ago, whatever. Good stuff. All right. Great guys. Kyle. Zach. See you later. Where wherever Zach is, yeah. He's out there.

SPEAKER_01 45:58

He just had to be disease centric sin.

SPEAKER_07 46:00

Yeah.

SPEAKER_01 46:00

Yeah. All right. Well, thanks for having me back on here, guys. Yeah, it's been a while. It's good to have you.

SPEAKER_06 46:05

See you on about a year. A lot of topics, yeah. All right. Later, guys. Later.

SPEAKER_05 46:35

Thanks for tuning in to the Owen Recovery Science Podcast. Before we go, a quick reminder that the information discussed on this show is for educational purposes only and is not intended as medical advice. Always consult with your healthcare provider before making any changes to your treatment or training regimen. For show notes and additional resources, be sure to check out OwensRecoverScience.com. And don't forget to like the show and subscribe for more evidence-based insights. Until next time, earn your D flight.