Barbell Shrugged - [Brain Health] How Exercise and Strength Training Impact Cognitive Function w/ Dr. Mike Zourdos, Anders Varner, Doug Larson and Coach Travis Mash #720

Episode Date: November 8, 2023

Dr. Mike Zourdos is a Full Professor of Exercise Physiology at Florida Atlantic University. He has contributed over 50 published research papers. He received his PHD in Exercise Physiology from Florida State University in 2012.  He is a regular contributor at MASS (Monthly Applications in Strength Sport).   Connect with Dr. Mike Zourdos Anders Varner on Instagram Doug Larson on Instagram Coach Travis Mash on Instagram

Shrug family, this week on Barbell Shrug, Dr. Mike Zordas is coming into the show, which is super cool because he is a full professor down at Florida Atlantic. And guess what? He is going to be talking to us about brain health, how exercise, nutrition, just kind of living this healthy life affects not only short-term brain health, we'll call that brain performance, but long-term brain health. And we all kind of know that we have gotten really, really good at understanding what are the right foods to be eating? What are the right training programs?

How do we build muscle? So we have this idea of like longevity and not having our bodies break down over time. But the brain is still a mystery. We're going to shed some light on overall what you can do to have not just the performance side of cognitive function in the short term, but what is the longevity side to brain health so we can stave off the scariest of brain diseases, dementia, things like that. It seems like that is really the big conversation these days is how do we keep our brains healthy so that our bodies are not just outlasting our brains. Almost impossible to say that without probably many, many people listening to this right

now going, oh yeah, I have somebody that deals with dot, dot, dot as they have aged. Many of our parents and grandparents specifically. As always, friends, you can head over to rapidhealthreport.com. That is where Dan Garner and Dr. Andy Galvin are doing a free lab lifestyle and performance analysis that everybody inside Rapid Health Optimization will receive. You can access that over at rapidhealthreport.com. Friends, let's get into the show. Welcome to Barbell Shrugged. I'm Anders Varner, Doug Larson, Coach Travis Mash. Thanks for hanging out, dude. Mike Zortos on the show today. He is a department chair down

at Florida Atlantic, and we're excited to have you here, man. And we were talking pre-show. This thing gets me fired up. You're 38. That brings you close to the big 4-0 number. We've all exceeded that line in the sand. But dude, we were joking, but it's a very real thing. There's no research that exists on being in the middle. And I want to dig into cognitive health and how exercise and brain health and all those things play together. But wouldn't now be a good time? Like studying people in their 40s to figure out where their brain is heading,

where their bodies are heading. What's the best plan to go handle if we're all going to live to 120 years the next two thirds of our life? I mean, maybe for you guys that are in your 40s, but those that are young and have their whole lives in front of them, like me, we I don't really see the reason for this yet. Yeah, no, there's no research needed for you in two years, for sure. No, you're right on the money. You know, there is there is one study

that I can think of that looked at young, middle aged and older folks in terms of the recovery from resistance exercise and recovery did tend to scale with age. So those around our age, fine, tended to recover maybe a little bit slower than the individuals that were younger, but not too much. The biggest disparity was between those that were younger and those that were much older, around 60 or so. So there is some, but it's very thin. It is not nearly to the degree. You see a lot of studies in younger individuals, 18 to 35. And the reason for that, as someone that conducts research, is you're mostly recruiting subjects from a college campus. And so you're going out, you're recruiting college-aged individuals, you're walking across campus, and you find those folks, and they come in. And then when we see studies in older individuals, a lot of times, these are really old individuals. Yeah. And, you know, not not just 60, we're talking 75, 80 and older

that are in these research studies. So in that middle ground, you're right, there's not a whole lot that's going on there. There is one study, and I think we're going to get into exercise and cognition a little bit. So we can go into this now. We can hold off. But there is one study that looked at kind of younger and more middle-aged individuals and the resting concentration, some biomarkers that are associated with cognition as well. But there is some. Yeah. Hold on.

I feel like all of it needs to be about us because when you're when you're in college there is no such thing as stress there is no such thing as not being able to sleep like if you have an 8 a.m class it's like you made the worst decision in the world it's like how did you get stuck with an 8 a.m you deserve it you're 40 and you have two kids and a job or a company to run and kindergarten. All of these things, that's all crazy amounts of stress. And if you want to go play the game when you're 80, when the next level of science comes in for the longevity stuff, all the damage is done in this stage. Yeah. What I'm hearing is that those at our age,

we are more important. Uh, everybody should recognize it. And, uh, hopefully after listening to this, people go out, they understand that, uh, and, uh, research picks up in this area. Yeah. It's just opened up a new bucket of funding. Yeah. R01 here at us. That's right. Take it away, Doug. Uh, yo, I saw this the other day. It coincidentally hits on many things that are interesting here. So, Michael, I understand that you have some knowledge in the velocity-based strength training world. Travis is also very interested in that world. I was actually just talking to Mike T. Nelson a minute ago about getting Mike, sorry, Dr. Brian Mann on the show so we can do a velocity-based episode. But Andy posted something the other day and that sent me

down a rabbit hole in PubMed. And one of the things that I came across was velocity-based strength training and its impact on cognitive function in older people, which I'd never really paired those two specifically together. I also did not read the whole paper. I just like saw the abstract quickly and then moved on with my life as one does with research. Isn't that what you're supposed to do? So actually I was going to ask you, Michael, more educated, less action. Yeah. But no, are you aware of that connection?

Do you, are you aware of that paper or other papers related to velocity-based strength training and cognitive function and or mental health and anything in that world? Tell me. I'm not aware of that paper specifically. So there is a comment, and I'm just taking some notes here as you're talking. And I have an overarching comment on velocity-based training, and then some thoughts on cognition. So what you just mentioned overarching comment on velocity-based training, and then some thoughts on cognition. But so what you just mentioned, looking at velocity-based training and cognition specifically are in those older individuals. So my first response to that is that when we think of something like velocity-based training, all that is, is a concept or a method to control for, let's say, proximity to

failure, which you could write, which you can do with RPE or RIR, or you can do in other ways or other methods and so forth. So they're just subjective though. I mean, do clarify there is quantifiable and subjective. One is quantifiable, one is subjective. One is quantifiable, one is subjective. Although I would submit to you that, and sometimes I think the subjective actually is a little bit better than the objective, not most of the time, but in some times. To give one example of that and so forth, let's say you have somebody's training and they're looking to train to a velocity that's associated with about two reps left. They have a technique breakdown.

That rep is a little bit slower. The objective is going to tell them they should stop the set. The subjective can tell them they know they still have two more and they can keep going if they want to, right? So there's just a very few circumstances there. But aside from that, just all of those things are ways to control for the proximity to failure for the effort level and so forth. So when we say like velocity based training can be positively associated with cognition. Sure. But it's, it's what they

actually did that is associated with it. So let's say for example, and again, I haven't seen this study, so I'm making stuff up. Let's say that those that were training to a 40% velocity loss. So they stopped this set when they've lost 40% of their velocity from the first rep. So to make the numbers easy, the first rep is 1.0 meters per second. They stopped the set when they fall below 0.6. Right. Exactly. 20% velocity loss group, they stopped the set when they fall below 0.6, right? Exactly. Well, 20% velocity loss group, they stopped the set in that same example when they're below 0.8. Okay. Let's say the 0.8 meters per second group had greater increases in a memory task following training. So somebody would say, Hey, velocity-based training is associated with cognition. Sure. But what that really means is that the group that

trained farther from failure was improving their acute memory or their long term measure or whatever that memory or whatever they studied. And you can train that way with velocity. You can train that way without velocity. You could take an arbitrary number like 70% of one around, you know, you can do 15 reps with that. And you say, I'm going to only do five reps. Now I'm super far from failure. Maybe I'll get this benefit or if failure is better, I can go, you know? So my first response is that when we think of something like velocity based training, I would look at it just as a concept conceptually, what is this trying to do? And then I can do that other ways because most practitioners don't have

access to velocity. Or if they do, they have a phone app and it may or may not be accurate in what they're getting. So there's other ways that they can control for that. They could create their own individualized percentage of 1RM chart, train to a certain number of reps. Obviously, that'll vary based upon how they're feeling. And then, trained to a certain number of reps. Obviously that'll vary based upon how they're feeling. And then they would be a certain proximity to failure about, uh, velocity, which certainly be better for that because it's objective. Um, but so in terms of the velocities relationship with, uh, um, cognition now, another way to look at that is that yes, maybe velocity does have, um, some sort of added benefit for cognition,

not because velocity is magic in and of itself, but because that allows that individual to adhere to training a little bit better. Their subjective nature just for them is not good. So they need that objective tool. Maybe the feedback, the external feedback of seeing the velocity or hearing somebody tell them the velocity is motivating for them. And so they train a little bit harder and that's allowing for that boost in cognition. So I don't know exactly what that specific paper showed, but what I would say about velocity based training is it's conceptually helpful to understand what it does. Shark family, I want to take a quick break. If you are enjoying today's conversation,

I want to invite you to come over to rapidhealthreport.com. When you get to rapidhealthreport.com, you will see an area for you to opt in, in which you can see Dan Garner read through my lab work. Now, you know that we've been working at Rapid Health Optimization on programs for optimizing health. Now, what does that actually mean? It means in three parts, we're going to be doing a ton of deep dive into your labs. That means the inside out approach. So we're not going to be guessing your macros. We're not going to be guessing the total calories that you need. We're actually going to be doing all the work to uncover everything that you have going on inside you. Nutrition, supplementation, sleep,

and then we're going to go through and analyze your lifestyle. Dr. Andy Galpin is going to build out a lifestyle protocol based on the severity of your concerns, and then we're going to also build out all the programs that go into that based on the most severe things first. This truly is a world-class program, and we invite you to see step one of this process by going over to rapidhealthreport.com. You can see Dan reading my labs, the nutrition and supplementation that he has recommended that has radically shifted the way that I sleep, the energy that I have during the day,

my total testosterone level, and my ability to trust and have confidence in my health going forward. I really, really hope that you're able to go over to rapidhealthreport.com, watch the video of my labs, and see what is possible. And if it is something that you are interested in, please schedule a call with me on that page. Once again, it's rapidhealthreport.com, and let's get back to the show. What I would say about velocity based training is it's a it's conceptually helpful to understand what it does. And so when we think of like a big sports team, obviously, if somebody has enough funds to get, you know, whatever piece of velocity equipment on all of the racks, that's more. Yeah,

yeah, if you have a gym, right, That's great. Right. You, you can, you can do that. Um, and, and that's going to allow those individuals to, uh, objectively control for that. Cause if you're leaving 30 athletes that are, um, just getting each other pumped up, yelling and screaming, you're like, Hey, just go based upon, uh, you know, auto regulation with RIR, they're going to overshoot it every time, right? So that's that's not a good idea. But anyways, long winded response for our first question. But I would say velocity based training, conceptually, that's kind of what it does. And so while yes, the paper could say velocity based training was beneficial for cognition, it was just the method that they chose to control whatever they were controlling for,

which you could do with something else. So you look at the outcomes. If it was that 40% versus 20% group, whichever group did better, the conclusion would be the training closer to or farther from failure or the more volume or the less volume was superior. And you could accomplish that in many different ways. Can I give you one more variable that to consider would be this is like, like compensatory accelerates, like true compensatory acceleration. Like the one thing that you'll notice, like if you have someone who can say squat 600 pounds and you say do 720, so 420, it's an easy five reps for them. So they can do it for five. You say, go do four by five with that. They could do it. Or you say, go do four by five,

maximizing each rep. And with getting that feedback each and every time their effort's going to be higher. And then you go look at like a lot of the studies would say a lot of not only exercise, um, it's the intensity of the exercise that you're performing that directs directly correlates more to the BDNF production. I mean, that's at least that's what Dr. Rady told us when he was on our show, but what are your thoughts there? Yeah, so this is something that I love talking about. Me too.

Yeah, this is awesome, man. So when we talk about BDNF, and for those that aren't familiar, that's brain, brain derived neurotrophic factor steroids for the cells of the brain. That's right. You know? And so when the easiest way to explain this, and then I, what I, but legal, but legal, sorry, what I want to do is then, then kind of explain this, of explain this physiology in a way, and then come back, circle back and get to Travis's question, which is around how to configure a session

to elicit this BDNF response. And so BDNF or brain-derived neurotrophic factor is a neurotrophin. Now, in the brain, obviously, as we age, we have a decline in cognitive function. And so right when you reach your forties, not at 38, but when you reach your forties, right? Why was it 50? You're just done. I can't even spell my name now. I didn't want to break it to you, but, but you know, and so we have this decline in cognitive function and neurons tend to die off or lose their some of their capabilities. Well, BDNF is associated with pathways with cell survival or neuronal survival. So we would call this neuro protection, the ability to sustain the function of those neurons more throughout a lifespan.

So the cool thing about BDNF is it is the neurotrophin that is most responsive to exercise. So exercise does a great job of stimulating BDNF. Specifically, aerobic exercise is excellent at this throughout a lifespan. Now, more recently, there's been literature in resistance training. And there's two ways to look at this, in which one of them is going to get back to Travis's point, which is that the acute response. So what we typically see is in resistance training studies, you look at an exercise session, and then transiently within the first 5-15 minutes, is there an increase in BDNF? And then there's long-term studies where we want to see the change in BDNF over time, the resting concentrations.

I'll get back to the chronic, the resting concentrations in a moment. But for the acute portion of it, Travis's question, we would think that acutely increasing BDNF is a good thing. Now, I caution everybody on that just a little bit and say that I think it's probably a good thing. But it is a little bit of a misnomer to extrapolate acute findings to chronic findings all of the time. But nonetheless, it would say an acute increase in BDNF is a good thing. Okay. So how do we do this to Travis's

point? You mentioned the intensity of exercise, and I think you nailed it. So not intensity necessarily in terms of percentage of one around, but in how hard somebody's working. So the early studies, which came out a little over a decade ago on resistance training and the acute BDNF response, they did not find that resistance training acutely increased BDNF. But when we look back at those studies, they were training farther from failure. They were training machine-based exercises, not a super difficult training session. More recently, there's a number of studies, two of them from our lab, that have looked at squat and bench press training to failure or close to it. And almost all of those

studies see a significant increase in brain-derived neurotrophic factor within that first 15 minutes after exercise. We carried out two studies. One of them was a longitudinal study that was six weeks long. And we had two training groups, a lower rep group that did six, four and two reps training three days throughout the week on squat and bench press, a lot of sets, high volume training protocol. And then another group, which did 12, 10, and eight reps. And obviously the load was lower to get more reps and the load was higher. What we noticed is we measured BDNF response in week one, pre and post exercise and week six, pre and post exercise. In week six, especially, we noticed that only the group that did the lower reps, not because they did the lower reps, but because they trained to failure a lot,

saw an increase in BDNF, whereas the other group didn't see that acute increase in BDNF. Now, this is not a commentary on training to failure for hypertrophy or strength or something like that. That's a different concept. This is only in the isolation of that BDNF change. We conducted another study. Now we wanted to see, okay, because for the general population that's interested in cognition and increasing BDNF, if you tell them they have to do, let's say that study just off the top of my head was roughly 15-ish sets a week of squat and bench press, all very close to failure. Most people aren't going to do that.

All of us in here will, but most people aren't going to do that. And so we wanted to see for make this more applicable, what is the more minimum amount of volume somebody could do and elicit this response? So we carried out a study, a crossover design study, one week squat, one week bench, one week deadlift, just four sets at 80% to failure. Four sets only of one of those exercises elicited acute increase in BDNF, but the intensity was higher and the training was at failure in that study. I'm not saying that you can't train shy of failure and still get it. You might need to add a little bit more volume. It might need to be a longer training session, um, as BDNF does seem to increase with a longer training session.

But the bottom line is what we do know, what we think we know about the acute change in BDNF in response to resistance exercises, the session has to be difficult enough to induce this response. So I think Travis's point is right on the money. Wait, how does the training for to failure concept pair with the cardiovascular response? Like if you're, say you're like a nurse or like a construction worker, like you're just moving a lot the entire day, you got eight hours on your feet or whatever it is, versus going for like a one hour jog five days a week versus doing like high intensity interval training where you're quote unquote training, training to failure, you're doing 400 meter sprints or whatever it is. how do all those play into BDNF production? Yeah, I think the more consistent way, to be fair, if somebody is training or just wants

to engage in exercise in general for the cognitive benefits, you know, certainly for general health benefits, you recommend both aerobic and resistance exercise, right? You would want to do both of them. You're missing out on something if you're not having both of those. But just from purely a cognitive benefit perspective, aerobic exercise does have more support and high intensity interval training has some support too. So they would lean into that direction. Now, we're certainly not looking at everything in a vacuum, because if all you're doing is that then you're missing out on the strength benefits and the muscle growth and quality benefits of resistance exercise. So if we're comparing those two, yes, I would say that the aerobic exercise or the high intensity normal training is probably the way to go. But I wouldn't necessarily want to make that binary comparison because that person is probably interested in more overall general health. The other component of it is, and to get to the question too, is that second component I mentioned earlier, which is the chronic or the resting concentration change. This to me is super, super interesting because there's, again, more support for aerobic

training over the longterm, but there's just simply more research. If you look at exercise science research, right, the plethora of resistance training research we've seen over the past decade is new. This is not the history of exercise science research. I know when I started out, you know, in 2008, as a PhD student, in 2012, as a professor, people like you want to do what? I'm like, I want to build a sweet powerlifting laboratory all right that's that's never going to work like okay thanks guys yeah appreciate it i'm gonna go do my thing now and uh um and so the chronic response so over time here's here's here's what's really interesting and i'll try to keep the physiology somewhat light, but I think this is interesting. What we're seeing is that the quintessential thought process would be since you see a transient increase in BDNF and BDNF promotes cell survival, promotes neuronal survival,

this that a resting concentration increase in BDNF is a good thing over time. But we don't always see that. Some studies actually show over time, those that are more trained have a lower resting concentration of BDNF. That sounds counterintuitive. But what we need to keep in mind with that is that when we're measuring BDNF in a laboratory, since we're using humans, we're not measuring it in the brain. We're measuring it in the periphery in circulation, right? I'm taking a blood sample and we're looking at it there. So if I see a lower resting concentration, I actually think there's more. What I think is happening is there's more BDNF bound to the receptor. The receptor sensitivity increases. And so more of it is over here, less of it is in circulation, but there's more total when you combine those.

In the brain, if you measured it, I think there would be a higher amount. And so the question is, can resistance training do this? I alluded to one study earlier when we were talking about our super awesome population of middle-aged individuals. And there's, I got you. I'm looping myself in. I can't fight it. I can't fight it anymore. As I said to you, uh, pre pre-show, um, in my classes, um, you know, the other day, somebody said something, they were, you know, they were struggling. I was like, Hey man, even Tommy Callahan got a D plus and just like the, stairs and so that's how i knew uh i was i was i'm losing it here a little bit i'm past my time and so that's sad that's sad yeah no it's it's it's

unfortunate you should have given your class an assignment to go watch that yeah yeah so my grad students i've i've given them so i have like a I've, I've given them, so I have like a box set. I've given them before Tommy boy, major league, uh, caddy shack, all these movies. And they, and I have to go watch them. I was, you're welcome. Get back to it. Sorry. And so that study it from De La Rosa at all, to get back to looking at the chronic changes. It was a cross-sectional study. And so what a cross-sectional study means is it's not training over time. It's comparing a group of trained individuals to a group of sedentary individuals. And this study used rugby players that had a good mix of resistance training and aerobic

training. And in the younger individuals versus the middle-aged individuals, the trained younger aged individuals had a lower resting concentration of BDNF as opposed to a higher resting concentration in the sedentary, more middle-aged individuals. Certainly, that higher resting concentration in the sedentary individuals is not a positive adaptation. So the question is, why is it lower? And I think it's lower because of the receptor sensitivity. They most certainly don't have less. Now,

I'm not a neuroscientist by trade, so I could be wrong on this, right? And I think that's always important in research and in science, which is I'm doing the best I can to interpret the data. We're doing the work that we do, and hey, could always be wrong on this. But I think that's probably what's happening in the De La Rosa study. So can resistance training induce this over time? And then how do you structure that program to get to it? But nonetheless, anyway, you want to look at it, the fact that exercise has this power to enact these changes and these neurotrophins and enact these changes to help promote survival of neurons and, and attenuate these processes with age is phenomenal. And so that's always the message I try to get across to people, and especially people that aren't us where exercise and lifting and so forth is just

part of their lifestyle. And they need a push to get into it and saying, Hey, I know you don't care about these performance benefits. I'm not sure why, but it's something that is an absolute essential part of your life when you realize what it can do for you and what it can do for you as you age. Yeah. What about the complication of the movement? Remember, I mean, when Dr. Brady was on a show, he went on to say that the more complicated the movement, the more activity of BDNF. So like even martial arts are gymnastics.

I want to add on to this when you're done. Yeah. My question is very similar to that in that you were talking about proximity to failure having a large impact, intensity or high intensity interval training. All of these things are kind of, or complexity of movement as Mastris mentioned. All of these things are kind of, or complexity of movement, as, as Mash has mentioned, all of these things are kind of like pushing the limits in multiple ways. Like one complexity, if you're, if you're high proximity or close to close to failure, you have to be more focused.

If you are, if you are lifting more weight or at higher intensities and interval training, your, you need more focus and intent to be able to perform those things correctly. This is a good question. And is the component that is important actually intent and focus where like mind muscle connection could also be a factor that plays into this? Is that really kind of the thing that unifies all this is that you can't go in, do three reps and act like you're going to get the same result. You actually have to try really hard and be focused and have the intent to develop the skill

in order to get the result of increased BDNF. So I think that's difficult to answer. I was writing down a few things here. So one, in terms of complexity, I think that's possible. And again, I don't know the individual you have on, he may know far better than me, right? So I'm not saying, hey, I don't know, I'm just going over the data that I'm aware of. And so I wonder if it's complexity or if I wonder if it's the amount of musculature that's involved. So there's a study from Alira that was a crossover design looking at the acute response of BDNF. And they had an upper body session, a lower body session, and then kind of a combined session.

The upper body session, which still had some complex movements, didn't elicit the same change in BDNF as the other sessions. But the other sessions had more musculature. Now it's just one data point, right? So I can't say that's what it is. But when I look back at the older studies, you could interpret that two different ways. Study from Go King specifically, I can think of off the top of my head, use more machine-based exercises. And so you could say those aren't complex, but it could also say those also don't use a lot of musculature. So maybe if there was a study comparing specifically, let's say the leg press, you know, to maybe a squat of some type, something like that, then you could maybe- Well, complexity is scalable. If you're going from couch potato to a leg press,

that increases complexity, which is going to have the same effect as somebody going from a leg press to a squat. It does, but if you have a trained individual that's familiar with both, one is going to have more complexity than the other. So we can make that comparison there as well. So anyways, that's a little bit different, but I wonder which one it is or if it's a combination of both. Right. I don't necessarily have the answer to that, but I think it's an interesting question that we would need to isolate out by just changing one thing in a research design.

So in terms of some of the other the other part of this, the kind of the mind muscle connection, you know, so what we're looking at there is kind of where somebody's focus is, is it an internal focus, um, on let's say the contraction of a muscle. So if I'm going to do a biceps curl, maybe I want to really have an internal focus. Um, I'm not so much worried about like, why are you doing this exercise? You know, you're not really interested in your biceps curl one or M you're interested in muscle growth, training, this assistance movement, getting more mass under the barbell, whatever it might be.

And so, all right, so I'm going to focus on that muscle focus on the contraction. There is some evidence to suggest that's a good thing. An external focus. I'm doing a bunch of reps on a bench press on a deadlift squat, whatever it is. I want to get that weight up, right? I want to, I want to focus on it. Um, not necessarily to really squeeze the muscle, um, a bodybuilder might, but I want to do as most reps as I can. I want to finish this one around. I want to get that weight up. So I'm not sure if the internal focus or external focus, how much that's going to matter for that BDNF response.

It could, I can see the argument for the internal focus, you know, mentally, or you're super focused on that. And that could have a greater improvement. I could see that, but I'm not 100% sure which way that would go. I would tend to say physiologically, if you are putting forth that effort and you're training close to failure or to failure on with a lot of musculature, it's going to have the effect regardless. I think that would be probably the more important component in my opinion. So it's possible that other could matter. I'd say, I don't know, but I would just say that the main point being training hard enough, training closer to failure, you know, having enough musculature there underneath the

barbell on the exercises you're choosing. There was one other note. It'd be a quick diversion on the complexity point that I can go into if that's okay for a moment. Please. Yes. That was, that was Masha's original, original question. Okay. I hijacked it. Way to go. It was a good question though. You made a. Yes. That was, that was Masha's original, original question. Okay. I hijacked it. Way to go. It was a good question though. You made a good question. That was good.

So for the complexity point, this goes into, and I'll tie this back into BDNF in a moment. This goes into the concept of exercise performance and mental fatigue. And so there's a plethora of evidence that shows also now in resistance training, as well as aerobic exercise, that when mental fatigue is high, before training performance tends to decrease. But specifically, the performance that tends to be impaired is performance of a long duration, or B complex tasks. Yeah. Yeah. And so if you have, let's say a, like some of the studies in resistance training on this induced mental fatigue, which is typically done through a computerized test. Sometimes it's done through playing on social media on your

smartphone for a while before you go into the gym. And so the early studies on this looked at, let's say a dynamometer, that's a fixed machine where somebody's strapped in and testing peak force or peak torque. And they saw that elevated mental fatigue didn't impair performance, but that performance is not of long duration and it's not complex. Studies now that look at reps to failure on a squat at 70% do show that acute mental fatigue impairs performance, right? So we're talking about a rep or so per sets. So maybe 15% performance impairment across three or four sets.

That is a little bit longer duration, although I wouldn't classify it as long duration exercise, but it is complex exercise. And so I think that's where the complexity component comes into it as well. And perhaps that is also the type of exercise that's going to have an increase in BDNF. So I think they go hand in hand there a little bit, but that's getting to that concept of mental fatigue as well and how that affects exercise performance. There's more to unpack here in a few different ways and looking at acute memory too. But I think that point on mental fatigue is important. And the literature on that is, is exploding quite a bit in recent years.

Yeah. That's what I did. My thesis on was fatigue and how it impacted performance. And it, it was pretty, it was pretty dramatic, you know, cause we looked at jumps every day compared to a front squat at 75 and 80% and, and a subjective questionnaire to get an idea of what they were going through on the day. And it was, it was quite obvious the more, you know, especially exam week, like performance plummeted, especially like, you know, we, uh, most of my guys do Olympic weightlifting. And so like that really took a hit and even the rate of injury started to increase. Wow. Yeah. I wonder, and with rate of injury, did, did you look into this true question? It's not, not necessarily anything that I'm aware of. So I think that's, that's super cool that you did that.

That was perhaps due to loss of focus due to maybe, um, just being so fatigued. They weren't able to perform losing technique, maybe not eating appropriately, all those other factors that come along with it. No, not sleeping. You know how it goes. Yeah, absolutely. Yeah. Mean professors like me giving those exams and then... That they had all semester to study for, but chose the night before to do it. Yeah. I get those emails. What's the mean professor's fault? I get those emails. Hey man, what's on the exam tomorrow? Sent from my iPhone. From the party with beer in hand.

I would just text him back, but it's too late. Keep partying. Keep going. Regarding BDNF, what other non-exercise means are there to affect that bar marker, increase that concentration, um, you know, sleep, stress supplements, et cetera. Yeah. All of those things, you know, so I'll say that first and foremost, outside of the effects of exercise on BDNF, it's really not fully my area since I'm not a neuroscientist, I've been kind of solely focused on extrapolating what I've done in the exercise realm to getting into this. But all of those things that you mentioned certainly can do that.

And then other ways to stimulate. So just continuing to be mentally active. So, you know, in what we do here, right, all of us here, we're always learning more about our field, and we're mentally active every day. And so I would just encourage everybody to keep learning to keep reading new things to keep striving to take on something else, you know, if we're just kind of, you know, going through the motions and not trying to continue to progress, you know, I would encourage everybody to continue to progress and whatever they're doing. Obviously, there's a whole host of other benefits with that. But everything you mentioned, the regular sleep, the appropriate nutrition, and then staying mentally

active with with those sorts of things. The other thing too, is about is about exercise. And so this this plays a role to get back into that question as well. Because the other thing exercise does, it has this increase acutely in catecholamines. So other things that we do that are going to have this increase in catecholamines, but also theoretically have a benefit for BDNF. And when we see that, when we exercise around a learning task, the increase in catecholamines is also associated with improved memory. And so there's a couple of recent studies that come out.

And I wrote an article about one of them recently. And they show that whether you increase before or whether you exercise before or after a memory task, within the next week or so, remembering what happened during that task tends to be improved as opposed to if you don't exercise. So in a recent study that came out, folks did aerobic exercise at a moderate intensity for 30 minutes and then had a memory task where they were shown a bunch of images. And a week later, they had to

determine if they saw that image previously or not. And then in another condition, individuals exercise for after that memory day at that memory task. And in both cases, if we see catecholamines tend to increase, something is committed to short-term and then long-term memory a little bit more readily. There's an increase in BDNF that tends to help with memory consolidation. And they remember what happened during those images or other studies have people read a paragraph and then recite that paragraph back. And so other activities too, or anything else that's going to cause that increase in noradrenergic activity or

catecholamines should theoretically have this benefit as well. So there's a lot going on there, but you know, in terms of exercise and cognition, talking about the acute effects of mental fatigue on exercise performance, talking about the ability of exercise to improve BDNF in the short and long term, and talking about the ability of exercise to improve acute memory, potentially with BDNF being a component in memory consolidation. Exercise is powerful, man. It's pretty cool what it can do all around. I'm interested, one of my favorite books of all time, if you're listening, go read it, The Talent Code, where it talks really about how Mylan impacts our ability to kind of learn, do the deep work, how you remember the skills.

Is there a relationship between BDNF and Mylan in that our ability to perform that task and increase the skill and the complexity and the intensity at what we're able to do that needs to be kind of hardwired into our body, which I believe is why myelin is so important. But you're also bringing in like the BDNF side of it and the brain health. And I would assume through that, through that the cognitive side and the hard wiring of the movement patterns and your ability to improve at that skill. Is there a relationship between those two and how do they work together? If that's the case. So, so myelin is like, for those that aren't familiar, the sheath around nerve fibers, right? So it increases the speed at which impulses are

conducted. And so BDNF has been shown to increase the thickness of that myelin, right? Or to preserve that thickness with age. So I think that there's no doubt that if BDNF is responsible or beneficial in all these things, there's that relationship with myelin. Because as that myelin erodes, as we get older, that the impulses aren't going to be transmitted as quickly, you know, the synaptic connections aren't as good. And so part of that neuro protection and neurogenesis process that we talked about is preserving that, right and preserving that thickness around myelin there. So I think BDNF is absolutely involved in that because that

is the structural part of those nerve fibers and BDNF is acting on that through the pathways it works through. Yeah. Kind of mash this question really got me thinking about that and, and, and like the full scope of like why the complexity matters, why the intensity matters. Um, is, is there some sort of, uh, deeper like survival? Really? I, I mentioned this when we when we interviewed dr rady um kind of like when when i think i actually used crossfit as the example of like we see such fast results when it comes when people start doing crossfit because their body thinks that they're about to die every single day when they go into the gym. Are there like survival mechanisms and how fast we're able to

adapt based on intensity or skill complexity kind of with these two or not even these two, but specifically BDNF and the importance of how fast we're able to really use BDNF or produce it. Yeah. So BDNF can increase pretty quickly, right? So we see that during exercise. In terms of a survival mechanism, are you referring to like a flight or fight response type of deal? Yeah. And it kind of goes back to if you go into the gym and you do 50% times five reps, you don't really hit those levels of intensity, but why, um, kind of, it's kind of like, why does it matter getting so close to failure? Uh, why does the intensity level matter? Um, like what is, what is driving that adaptation? Because it's hard to say. So I have one theory. And again, always prefacing this with I'm not a neuroscientist. So the individual we had on before may have more insight than I do. And then somebody

else may know a bit more about the topic. But Dr. Rady, you should totally read. Have you ever read Spark? I haven't. Where is he? I'm going to look him up. I very much. San Diego, right? No, Harvard. He's a professor of psychiatry. So better than me. The San Diego part is there's a, this is what I actually follow on Twitter. There's a school in San Diego, it's a private school or maybe a charter school,

who built their curriculum around movement and play and increasing complexity and then running all the test scores that public school kids and they slaughter. Oh, there's something I want to tell you. I can't announce it because their entire curriculum is built around play and movement. Yes. They scatter in reading, writing, arithmetic into that, which is literally like the where I want my kids to go to

school, but they don't have one in Raleigh, North Carolina. Um, there might be one near Winston. Sounds like it might be moving too. Um, but go ahead. Sorry. No. Um, so the, the one thing I can add to this discussion is we've also looked at a, another biomarker called cathepsin B. And so this is a protease and skeletal muscle. It's a myokine. A myokine is a cytokine that's released from the muscle tissue. And cathepsin B crosses the blood-brain barrier to act on promoting BDNF. And so to tie into your question, cathepsin B tends to be increased when AMPK is activated. So AMP kinase or activated protein kinase. And so when AMPK is increased, that occurs when glycogen is low.

And so that's one of the reasons that aerobic exercise is good at activating these biomarkers. So training closer to failure or a long duration training session, right? Resistance training is not typically a glycogen depleting exercise, but a really longer duration training session, something that's especially intermittent. So you mentioned CrossFit, something more of that nature is more likely to have this effect of increasing AMPK. That could then facilitate an increase in kithepsin B, which could potentially have an additive effect on BDNF. So that's one reason why that interaction between those two markers, why BDNF, it could be important to train closer to failure to have this increase in BDNF.

And so the duration of exercise, I do think is a component in that, which is why aerobic exercise tends to be favored for these types of responses. So the one component I can add is perhaps that cathepsin B could be a part of this as well. Now, we have looked at Cthepsin B in our research too. We have not been able to see a response in Cthepsin B in those studies that we did training to failure. Cthepsin B was not acutely increased. It doesn't mean there wasn't still anything going on there. It doesn't mean resistance training can't facilitate an acute Cthepsin B response. I think that the protocol probably needs to be of longer duration than the 30 minutes we had individuals train for. Now, in the De La Rosa study I mentioned earlier, that was the cross-sectional study that compared the younger folks and the rugby players to the

more middle-aged individuals. Cathepsin B also had a reduced resting level, just like BDNF in the younger trained individuals. So there was a chronic change conferred in Catepsin B. Now, the way those individuals are training, they also included a lot of aerobic training. So they may have had acute changes in Catepsin B. But here's just another question, which is, and I don't know the answer to this, is an acute change in something a prerequisite always for a chronic change? I'm not so sure. Definitely not. Like we know one, like the hormonal response during weight training is not really related at all to chronic and hormonal response.

And therefore, it has nothing to do with muscular growth. So which they forever thought it would, which is why they were doing the 30 second rest and killing each other. But then they found out it didn't matter at all. So- Correct, yeah. So we're aware of that, right?

So, and that's the old school hormone hypothesis, right? Yeah, rest for 30 seconds, get these acidic conditions, get better binding of growth hormone, releasing hormone, GH goes up, testosterone goes up, you know, and it doesn't matter. Good job. Yeah, doesn't matter, right? Doesn't matter. You should probably take longer rest, complete some more volume, at least when sets are equated. If you want to train, take shorter rest and do some more sets to equate for volume, that's probably fine, but for sure.

But in this a little bit of a different question, which is that just in terms of the biomarkers themselves, independent of that adaptation, do you need to see an acute increase to see a long term change? Can you not can exercise not change cathepsin B acutely resistance exercise exercise and still have a chronic change in that biomarker, just the biomarker in isolation independent of performance outcomes. That I'm not so sure, because aerobic exercise does seem to change could have some be acutely and does have a chronic change resistance exercise so far hasn't the study that looked at cathepsin B acute changes was from moon et al, it was in mice, and it was just monster of a protocol. Good luck to those mice, where they were just super depleted. And so that's a question that I'm interested in. But any short diversion into reminding everyone

that the hormone hypothesis for resistance training for 30 second rest for hypertrophy isn't a thing anymore, I'm always on board. Right. When we start to dig into kind of like a long term game plan for this, you know, kind of bringing it back to the beginning, we're talking about how all these studies happen when you're in college, and then when you're in your 80s. If we were to really lay out a path for improved cognitive health late into your 40s, 50s, 60s, what is like a tactical plan that people can have a long range outlook for really what is the most terrifying thing that faces humans outside of international politics, but brain health, very timely comment, brain health, and really making

sure that we can, like, we figured the body out pretty pretty good but we haven't figured the brain out that well um so how do we how do we build a long-term approach to um making sure that we're able to keep our brain health so i have two things that would be the scariest thing um one would be waking up in the morning to train and realizing that i'm out of caffeine um that'd be just awful right yeah the second i got in trouble i dropped into my friend's gym this morning travis mash where you spoke the other a couple months ago yeah i walked right into the gym floor and got yelled at bring coffee onto the gym floor everybody looked at me like i was visiting and i walked in i was like good morning people and they go uh everybody

just looked at me like i was the dumb kid first time ever in a gym they're like coffee's gotta go buddy it's like how am i supposed to have energy it's 7 a.m yeah it's like come on come on new guy i know um i would say come on to them i'm going to the other gym but yeah the the other scariest thing is uh when when i'm coaching my son's soccer team and all like 15 kids are sprinting at me to tackle me after practice. I'm like, this is my nightmare. Would you rather fight 1,000-pound duck or 1,001-pound ducks? That's it.

There you go. And so to answer your question, you know, the most important thing is start now. What does somebody always tell you that you wish you knew? When you're older and you wish you knew and you're getting your life together, they show you those sheets when you meet with your financial advisor and say, if you would have invested when you were 20, you would have had this. If you would have invested in your brain health when you were younger, you would have started that process. If you would have started resistance training when you were younger, you'd be on your way to

attenuating sarcopenia. Start now. Start as soon as you can. It's not too late, right? If you haven't begun this process yet, it's still beneficial to start, right? But start as soon as you can. Now, assuming we're past that, and everybody's all right, I'm exercising, I'm good to go, what can I do? Or, you know, I'm going to get into it, what should I do? So the biggest word that I wrote down here was sustainable. What is sustainable for somebody? So we think about those of us that have been in the lifting world, and what we've done. And I'm sure there's been times where there's been training blocks and you sit down and

you write out that training block and you calculate out the numbers. You're like, dude, in six weeks, I'm going to squat 800 for five at this. This is going to, I'm going to crush it. And then you get like to your second week or you get to your third set on your first day and you're like, oh, this is never going to work. Right. I think you just described a hundred percent of the training programs I've written for myself. Me too. Oh, if I, if I could go back and start, um, my super mediocre powerlifting journal journey all over again, I would 100% on day one, hire somebody to coach me. I was the absolute, yeah, I was the worst coach of myself. And so, you know,

it's got to be sustainable. So when we think of that, everybody's thinking of training, think about when you've written yourself a program and something like that has happened. And so there's a lot of different ways to make things sustainable. So we hear all the time, well, somebody has to enjoy training. And yes, that's true. But I wanna talk a little bit deeper than that because sometimes that's very esoteric, right?

You can't really put it together. And I don't say somebody just enjoy it. Well, what's not super helpful? And so to put a little more meat behind that, if we take somebody that is starting out, that is newer to this, and they just want to get into it, you know, there's a concept out there that's called exercise snacks. And exercise snacks are just as they might sound.

This research started just for general health and to looking at changes in blood glucose, you know, changes in sedentary individuals. And they would have individuals 10 times a day, walk one single flight of stairs. They're at work, they get up and walk a flight of stairs. So they walk for one minute or they sprint for one minute. That's it. They saw beneficial changes. Now, I'm not saying this is better than normal training.

That's compared to nothing, right? But it was a way, a method that was sustainable to ease them into it, right? Not saying, hey, I want you to go run for 30 minutes. I want you to go do a bunch of squats, right? Disaster for that person to sustain that exercise program. So again, that's conceptual. It doesn't have to be 10 sets of a one-minute walk or a sprint or something like that again, that's conceptual. It doesn't have to be 10 sets of a one minute walk or a sprint or something like that for somebody that's newer to it or somebody that wants to sustain it. But it's the concept that that's a way potentially for somebody to enjoy training, to adhere to it. And then once they start to see those quantifiable benefits, because we love quantifiable benefits, we say, oh, look at my numbers here. Look at that progression I'm seeing in my body

composition, whatever it might be, that I'm going to stick with it. Can also do this in strength, right? You can say, all right, you know, I have just this little bit of equipment here at home, or I have this a little bit of equipment here at this office or this workplace gym or whatever. I don't have an hour to go in. Fine. You have five minutes here, five minutes here, five minutes here, right? That's 15 minutes throughout the day for somebody who was doing nothing. You did nothing. Now you do something, right? Look how much better you're going to get. Now that has to progress over time, right? That's the progressive overload concept. But you do nothing, you do something, and that's what they're going to get. So the biggest advice or the biggest thought process is start now, find and that's what they're going to get. So the biggest advice or the biggest

thought process is start now, find something that's sustainable for you, which could be entirely different from what's sustainable for somebody else, right? The biggest kind of diatribe I've been on recently is research isn't there to tell you how to train. Research is there to give you concepts. And then you take those concepts and you apply them. So what's the concepts? Oh, exercise is good for brain health and BDNF. All of these different forms of exercise. Great.

This person, right? You go to that holiday party or whoever, and they see you. You're somebody in your family, your cousin, whoever. Like, hey, you're so-and-so. You're the, this is what they always do. Say, you're somebody in your family, your cousin, whoever, like, hey, you're so-and-so. You're the, this is what they always do. Say, you're the exercise guy, right? They do that arm movement, exactly. Yeah, yeah, yeah.

You do the training. It's always a quarter bicep curl. Yeah, yeah, always. Yeah, just like that. That's how I do it. That's me. I was going to get the half overhead dumbbell press. It's like this.

That's when they ask you. Mostly from my mother-in-law. That's when they ask you if you do power lifting they do they do the overhead presses i'm like close enough guys it's like a it's like a 45 degree angle press we're like is that a bench military i don't know i don't do that one though yeah whatever you want it to be and so research i get the weight of their arms and immediately followed by again from my mother-in-law what do you do again you ask me like every week for like the last 10 years it's it's no it's okay i have i have so much more to add on that it's like

it it reminds me of when i told my parents in 2003 that i was changing my major from communications to exercise science. And they were just very confused that this was the thing. And then it wasn't until the last year of my PhD in 2012. I mean, they're always the most best parents and so supportive. They're amazing, but it's not what they do and and uh they came to visit me in tallahassee florida state and i was in the in the lab uh doing some pipetting and like they they could kind of see and i was just kind of focused kind of like hold on okay i got it it is and um i could see it was like oh you do science you can have it you're gonna get a real job i thought you taught people how to do push-ups

yeah and i was like yeah and so it's it's amazing um but to go to that that that if we're back in that holiday party mode that person that gives you the universal lifting sign the research is giving you concepts that you can apply to that individual right because you know that individual you know what they enjoy right they know, what they enjoy, right? They enjoyed playing basketball, they enjoyed playing soccer, they enjoy playing hockey, whatever it might be. And then you find that thing that they might stick to. And that's what's sustainable for them. And it's completely different for somebody else. And now whatever that thing is, they need to keep doing it, they need to progress it, they need to stay with it. And it might not just be one thing, right? It might be do this year and then do this year. You know, I'm a big

proponent of you got to give people a lot of what they need while giving them some of what they want. Right? Somebody wants to do this in a program. And you're like, ah, you don't need to do any bicep curls for this. Well, they're going to go find a new coach, because trust me, they want to do bicep curls. Right? So for that person, research doesn't tell you how to train. Research gives you concepts, you understand them, and then you apply them. And when you apply them and you're good at applying them, you can find something that's sustainable for that individual. And I would encourage all the coaches and practitioners out there.

You are probably better at applying those concepts than the scientists. The scientists, I- This is a big admission right here. I'd be careful for the scientific community. They're coming after me. Dan and Andy are mad right now. Stop him from talking. He's right though.

I know my audience. I'm going on a science podcast after this, and I've got my other script, right? I just flipped this paper over and I read this, you know, and I tell you, you know, and, you know, so as someone that, that, that is in both worlds, probably mediocre at both, but that's in both worlds, you know, and that's really, it's a bigger question, but we need, and this is why what you guys are doing is so awesome. We need more interaction between both because both sides need each other. And, but that's what researchers that are doing. I think if we do that, we can get to the key point to get back to your original question is what do you tell somebody you get something that's sustainable for them. And that's how

they're going to manage it over the longterm. I have thoroughly enjoyed this today, sir. Where can people learn more? Is it too late to ask one more question? Oh, go do it. I was going to ask you earlier, you said, you know, proximity to failure when it comes to like muscle growth, you know, you know, so like, I would like, you know, maybe the short answer on that one. I'm not sure if I can give a short answer. So Travis, you just cut me off when the, the time is, you're good. There is no time unless you're up against something. I'm up against my my lunch that's waiting for me,

but I will persevere. I will. And so. All right. So proximity to failure and hypertrophy specifically. I'm sure as I get into this, I'll get back to strength, and we'll define proximity to failure first, which is, let's define, you could probably define it a few different ways, but we'll define it in terms of repetitions and reserve. How many reps are you from failure? Are you at zero? Are you past that, meaning you actually failed on a rep? Are you one rep shy, two rep shy, three rep shy, or so forth? You could come up with another definition, but just to kind of make this conversation what we're doing. Then also, when we say failure, we have to define what training to failure means. There is different definitions of this in the literature. There's momentary muscular failure, which is actually

failing. Then there could be volitional failure, which is somebody stopping on their own volition. Now, in a research study, that person could be at failure or could have zero repetitions in reserve, but they could also have three repetitions in reserve and just decided that they didn't want to do anymore. I think three is a bit far, but just to show the point, volitional is different from momentary. All right. So the conventional wisdom over the years, let's say, has been to abide by the principle of effective reps in that, in short, the closer you train to failure, you're going to get more muscle growth. So training at five repetitions in reserve won't get you as much muscle growth as four or three won't be as much as two, one or zero. And when we think about that

concept, it makes a lot of sense when we consider how muscle fibers or motor units are recruited. And so I am not going to talk about this as eloquently as someone like Andy, that's his area. He is the expert, but I'll do the best I can to my ability. And so if we have generally, not always, right? It's not this binary, but for the purposes of this argument, right? Higher and lower threshold motor units. So a motor unit being a motor neuron and all of the muscle fibers that it innervates. So throughout a set, historically, we think of motor units being recruited sequentially. And I'll get this to why this matters for proximity to failure in a moment. So lower threshold motor units are type one

fibers being recruited first, and then type two fibers as needed. Well, type two fibers, typically, we think of having a greater propensity to grow and change, although type one fibers, of course, grow as well. So if somebody's training far from failure, they somebody might say, Okay, well, you're not recruiting all of your high threshold motor units. And so logically, it makes sense. Yeah, we got to get closer to failure. Besides, it kind of feels awesome, especially on some certain movements when you train closer to failure anyways. So let's do that. Makes sense that you're working harder. You recruit those high threshold motor units and you'd get more growth.

The other component of that is that type one fibers, while they're exhausted, they have a long shelf life in that they're pretty resistant to fatigue, but they're not super powerful. So if you just do a one RM, yes, you need high threshold motor units. The type one fibers aren't strong enough to do that contraction alone, but they're not actually fully fatigued because they have to go through a long duration. So by going to failure on more moderate higher rep sets, those type one motor units are getting fatigued because they're going through the longer duration and you're recruiting the high threshold motor units. Thus, it makes a lot of sense to say, hey, the closer we train to failure, we're going to have a relationship with more

growth. All right. So is that the case or not? And I think that we could say, we still have some questions that are up in the air. But I'll start with the most recent, which is that our laboratory, led by the most amazing PhD student in the world, Zach Robinson, my student, who I'm so proud of, and it's just far exceeded my capabilities. I can't stress that enough, led this meta-analysis and did an absolutely amazing job on it. It's out as a pre-print. It's not published in a journal yet, but it's out in a pre-print, so it's free for everybody to read is what that means. And so we wanted to see what's the relationship between repetitions and reserve and muscle growth. Now, a few caveats before I get to the findings here, and some may be familiar. I'm not a huge internet guy,

but I do go on the line occasionally. And I hear that it's been making the rounds out there. And so we wanted to see when volume is equated, and that's a big component here, when volume is equated between training to failure, not training to failure, not what causes more muscle growth, failure or non-failure, but what's the relationship between RIR and muscle growth, meaning all the way from, you know, as far as studies train from failure, all the way up to then zero RIR and momentary muscular failure. So not just as failure better than non-failure or vice versa, but what's that relationship. And I've been of the opinion for

some years based upon looking at each individual study that you can train shy of failure and maximize muscle growth. And I've been a little bit out there on an Island. Um, although I'm not writing a lot of public articles, I write in the mass research review, which is which is behind a paywall, but those that have seen that, where I've been a little bit out on island saying, I think you can train a little bit farther from failure than most people think, provided you do enough volume and maximize muscle growth. Zach and I and other PhD students, we worked on this, we collated the data, Zach ran the analysis, he's wonderful with statistics, and found that the slope of the line between, if we look

at RAR and muscle growth, kind of went like this, right? Whereas that individuals, when they got closer to failure, they did grow more. And when they were at failure, they did grow more than a one RAR. And for me, I wasn't expecting this. And so he showed me this and I was like, no way. Are you telling me that, you know, that I was wrong? Because you're my student, as far as you know, I'm never wrong. And so we looked at it and findings weren't exactly what I expected. But hey, that's awesome, right? That's what science is. That's why you do these things and answer these questions. findings weren't exactly what i expected but hey that's awesome right that's what science is that's why you do these things and answer these questions you don't care what the

answer is you care that you find the answer and that you strive and you get better right that's important so important right who why would so and this is what's so interesting to me about this topic um and so what we found was and i'll'll break it down more, is that there tended to be a relationship when volume is equated between training closer to failure and muscle growth. And so those that would say, hey, you should train to failure based upon our results, it did tend to show that relationship. Okay. And so now take back up for a moment from a lens out. And I would say that a lot of people, for some reason, I don't know why, but for some reason, this topic is very polarizing.

People really hold to training to failure or not training to failure. For me, somebody say, well, you know, what do you, you know, which one? Or it's like, I don't really care. I just want to figure out what is best. Right. Yeah. This really is irrelevant to me. I had somebody send me an email one time. They read my dissertation. This was like a decade ago. And they were like, Hey, I saw that work you did on some, uh, periodization stuff. It looks really good, but, uh, I don't train like that and I don't want to. Okay. Cool. Good. That's fine. That's fine. I don't know why you sent me that email, but that's fine. And so I hope you feel better now. Yeah. Great. Congrats. All the, all the best to you, my friend. And so when we, when we look at

that, you know, I think when we, we step back and a lot of people have made a lot of progress by training to failure. A lot of people have made a lot of progress by not training to failure. And despite any results, those are both very valid. Because you can make progress both ways. So the one thing I would say is, even if there's a relationship, go ahead, Josh, you have a question? Oh, even there's a relationship between RAR and muscle growth. It's not like somebody trains to two RAR and they don't grow at all. Right. And so I think that's one of the misconceptions as well. Additionally, there is a such a high inter-individual variation in what people respond to. People do respond to different things. And I think different mechanisms such as mechanical tension and the metabolite mechanism of hypertrophy can manifest in different ways. So one of those mechanisms could have a little bit more importance for some people than for others. Oh, man. Yeah.

I haven't heard anyone else say this, the individualized approach to hypertrophy. So to me, this is the most pressing question that we can approach in resistance training. Because when you see so many people out there doing this and doing this and doing this and doing this, not all of the top powerlifters are doing the same training. Not at all. But they're still making really good progress and crushing it out there. Why is that the case? Just maybe somebody responds better to this than they do to this.

The question is why? Once we can find out why, then we can really target some of our training programs to specific individuals. So there are within subjects design studies that are looking at, and then I'll tie it back into proximity failure, but there's so much to talk about. Within subjects design studies that are looking at the responses to different training programs like rest pause sets and drop sets and traditional sets. And what we're seeing is that some people legitimately respond better to rest pause sets and other people respond much better to traditional set trends. I'm going to go down a rabbit hole now for sure. I'm doing this thanks to you,

but I'm so excited. This is great. Yeah. And it's so cool to look at and it's all about finding what's the best answer and why is this happening for that person? And, you know, cause if you, somebody's like, oh, well, you know, I love, um, if you love doing a certain type of training for yourself, that's awesome. But it's like, well, I love, and I think everybody should do this type of training. Everybody, um, you know, there's, there's, you know, that's a, that's a, that's a big, that's a big jump. There's, there's baseline principles that are true, right? Like I say this all the time

and that there are so many different ways to do things right. You can be wrong, right? There is something that is just, you shouldn't, don't do that. But there's these 500 other things that you could probably do and which one works. So when we go back to the hypertrophy example, there's people that have made progress on both sides of this, right? And why is that the

case? I think they can both be effective. So getting back to the meta-analysis, the important component I mentioned is that volume was equated. So now the question then becomes, all right, if you don't equate for volume, can you, if we go for the sake of argument that training to failure is better than not training to failure, training to one RAR is better than training to a two RAR and so forth. And I'm not completely sold on that based on our findings, but let's go with that for the moment. Can you add more volume to non-failure training to then raise your growth to meet what you would get with failure training? And if so, how many more sets or how much more volume load? If we use sets because it's easily quantifiable here, if three sets of training to failure on a leg extension gets you this much muscle growth. Does four sets or five sets of training to a one RIR equalize that growth? If five sets does, does seven sets of training to a two RIR get you that muscle growth, right? So what's the slope of the relationship between the

change in RIR, or excuse me, the change in sets and the change in RIR? Is it linear? Is it every RIR you need two more sets? Is it a half a set? Is it not linear? I don't know. And I also don't know if you can then actually equate for growth if you do more sets. I'm not saying that that's a thing, but I'm saying we don't know the answer to that question yet. And I think it's an important- It's a good question. Yeah. Yeah, right. It's an important question because there's pluses and minuses to that. One, that's a lot more time for somebody in the gym, let's say. Yeah. So maybe they don't want to do that. On the other side of it, this individual, we always have to think of the downstream effects, in my opinion, of doing something,

the indirect effects. If somebody is constantly, constantly training to failure, that's mentally exhausting. That's also the fatigue that manifests is a little bit longer acute studies. And there's a caveat to this too, but acute studies that look at muscle damage in the following days from failure training, muscle damage and fatigue lasts longer than non-failure training. So perhaps you could argue not training to failure. They'd be recovered a little bit more quickly. They could do a little bit more volume and perhaps that's the way to go over a very long term in that case. I don't think it's that simple because- I would say it's very individualized. Just anecdotally, like I have people who can go super heavy, like Nathan Dameron. He can go heavy every day, but if you do high volume, moderate, it kills him. You know, me too. Exactly. Exactly. And, and if you go, I also think that the repeated

bout effect kicks in, which is the attenuation of muscle damage when you repeat a bout of exercise. And that's related to volume and intensity. So somebody is always training to failure over time. Does that fatigue that lasts for the next few days kind of go away? It's not as, as bad each time. And then you could probably get away with it. And so there's real quick, is it, wasn't your boy, Andy Fry, the one who did the study about how high intensity, low volume created less fatigue overall especially you know internal stress then like high volume low intensity of course it's kind of a different question but you don't remember the exact that exact so he did a lot on overtraining yeah they would they would they would hit one rms like 21 rms a day every day for two weeks and that type of stuff but i don't

remember specifically the studies i've read the paper it's just been it's been a couple years but one rms like 21 rms a day every day for two weeks and that type of stuff but i don't remember specifically the studies i've read the paper it's just been it's been a couple years but yeah so dr fry's the man um legend in our field um we've met once i wouldn't expect him to remember me uh but uh what what a what a great guy and that so that, this is again, but that paper you're talking about, that was inspiration for me. So 2015 ish, I did, um, a daily one RM training study where I did a case series, had individuals max squat for 37 consecutive days. Um, and looking at the results, this meant I, I, I had done this on my own. Um, so I max squatted for about 150 consecutive days at one point and started doing it twice a day.

Exactly. And, yeah, yeah. And so Dr. Fry's paper, though, while wasn't the exact same thing, I was like, Oh, all right, so I won't, I'm not the only idiot that is interested in something like this. This guy sounds awesome. Like, you know, and so we did that case series on that. But to your point, Travis, yeah, so so higher volumes is going to be associated with more muscle damage. And so that's going to manifest. And so there's a lot of caveats to making a decision to train failure or not to failure, then we have to consider two other components, the exercise selection, right? If somebody is going to train to failure all the time on biceps curls, probably fine.

If somebody is going to train to, to, um, failure all the time, um, on squats and deadlifts, you know, probably not sustainable. Um, and, uh, some other things to take into account there. So when we consider the exercise selection, maybe they open themselves up to injury, just because their technique breaks down, they're trying to ground that last rep, that sort of thing. So I don't think it's it's quite that binary decision all the time. The last quick point to make on this is that when we consider failure or non failure, how many if if failure is better, which again, I'm not sure it is, but if failure is better for muscle growth, how many sets need to be taken to failure?

Is it really every single set or can you do three or four sets, not to failure, take that last set to failure in each session? We got to do a follow-up call on this, but yeah, we're doing it. Get them the zoom link, get them the Calendly for sure. Yeah. We got to talk hypertrophy, man. This is awesome. Um, where can people find you? People can find me. Uh, if you're interested in research, go to Google scholar, pub med, you can find me and my students, all of our research that's out there. Um, it's honored to work at FAU with so many great students, uh, Zach Robinson, Josh Pelland, and Jake Roman, my PhD students also, uh, mass research review, uh, Roman, my PhD students. Also, Mass Research Review,

massresearchreview.com. I put it out with Eric Trexler, Eric Helms, Lauren Colenzo-Semple, other scientists in the field. Every single month, we break down studies specifically related to strength sport. And we're branching out a little bit into kind of health, fitness, and other exercise modalities in general at massresearchreview.com. Check out, we have some free content. If you want to subscribe, cool. If not, it's an honor to work with those people. And thanks, guys.

There you go. Coach Travis Bash. Go to mashalead.com. You can go to Instagram at mashaleadperformance or Twitter if you want to talk to me. That's at mashalead. There you go. Douglas E. Larson.

That's one right there. Here's that. Instagram, Douglas E. Larson. That's one right there. Here's that Instagram, Douglas E. Larson. Michael, appreciate you coming on the show. We've had Lauren on here recently, and we also are going to have the rest of the mass research review team on here very shortly. So we'll get the rest of your crew out here for the world to hear their advice and suggestions.

Thank you for coming on the show. Yeah, man, this is great. I appreciate you coming on. I'm Anders Varner at Anders Varner. We are Barbell Shrugged to Barbell underscore Shrugged. Make sure you get over to rapidhealthreport.com. That's where Dr. Andy Galpin and Dan Garner are doing a free lab lifestyle and performance analysis that everybody inside Rapid Health Optimization will receive.

You can access that over at rapidhealthreport.com. Friends, I'll see you guys next week.