April 8, 2021

"BCAA Supplementation for Enhancing Muscular Strength and Hypertrophy" with Professor Kevin Tipton

"BCAA Supplementation for Enhancing Muscular Strength and Hypertrophy" with Professor Kevin Tipton

Episode 158 of the Institute of Performance Nutrition's "We Do Science" podcast! In this episode, I (Laurent Bannock) discuss "BCAA Supplementation for Enhancing Muscular Strength and Hypertrophy" with Professor Kevin Tipton (The Institute of Performance Nutrition, UK).

Discussion Topics Include:

  • Overview of Branched Chain Amino Acids (BCAA) as a popular supplement in sport and exercise nutrition
  • BCAA s integral importance for skeletal muscle protein metabolism
  • Physiological roles and characteristics of BCAAs, EAAs, and Leucine in enhancing muscular strength and hypertrophy
  • The data and evidence on BCAAs: the early rodent data vs human studies
  • The many important factors that may influence findings on this topic
  • From science to practice: summaries and conclusions

Podcast Episode Transcript: Download PDF Copy

Key Paper(s) Discussed / Referred to:

Related Podcast Episodes:

Check out our other podcasts, publications, events, and professional education programs for current and aspiring sports nutritionists at www.TheIOPN.com and follow our social media outputs via @TheIOPN



We Do Science Podcast


APRIL 09, 2021

"BCAA Supplementation for Enhancing Muscular Strength

and Hypertrophy"

with Professor Kevin Tipton PhD 

[00:04:57] LB: Hi and welcome back to the Institute Performance Nutrition's We Do Science Podcast, and today I am bringing back our resident expert, Prof Kev Tipton. Hi, Kev. How are you doing? 

[00:05:09] KT: Oh! Fine. Thanks, Laurent. Good to be here again. Good to do another pod. 

[00:05:13] LB: Well we're going to have some fun today I think. There's a number of topics that are constantly at the high-end of the hotly debated zone particularly on social media and gyms and so on and so forth and those because sports nutrition can be a very popular and hotly debated topic. And one topic that constantly seems to be at the top of that sort of pile of things that people like to get their knickers in a twist over, it is things like branched-chain amino acids. Whether or not we really need to supplement them? Do we see some people taking these supplements literally between sets at the gym? The concept of forgetting your protein shakes. It is well known that people can get really rather worried about the fact that they are not achieving or hitting their leucine triggers, they're losing thresholds and so on and so forth. And of course we get into these debates about do we go down the food first approach? Do we supplement? Whey is way better than casein or is better than animal protein? Hold on. Maybe it's not. Maybe all these sources of protein are perfectly adequate. It depends on the context. Aare you young? Are you old are you vegan? Are you under eating? Are you overeating? There're all sorts of stuff.  

But let's really get into this topic, because we were caught through on a recently published paper in the International Journal of Sports Nutrition and Exercise Metabolism which was titled Isolated Leucine and Branched-Chain Amino Acid Supplementation for Enhancing Muscular Strength and Hypertrophy, which of course was a narrative review and there are many other studies that exist out there. And you've done original research in this area. So I’m particularly lucky to have you here in front of me, Kev, to talk about this. 

But as a practitioner – In the old days, as a very much a consumer or an over-consumer of supplements, for example, I do find this fascinating. The fact that in this day we're still having these issues, these worries, these debates. And often very intelligent people are debating. It's not sort of bros in the gym. There is a genuine reason for confusion on this topic. So here you are Kev to help us understand this topic. So let me direct you a bit. Firstly, why did this review come about? Do you know? And it's 2021 and we're still having these hot debates about BCAAs. What's all this about?

[00:07:36] KT: So this particular review was led by Brad Schoenfeld. A couple of his students led the way on the writing of it. Brad invited me on board because of my previous work with branched-chain amino acids. And again it came up for what you were alluding to, is that it's still a really popular supplement. It's a really hot topic.  

This morning just to sort of get ready for this pod I had a quick look on Google and YouTube and there are still hundreds of videos telling me why I need to supplement branched-chain amino acids. So despite previous reviews and publications that we'll talk about sort of refuting that, it's still very popular, and for all different reasons it seems like I’ve seen webpages or YouTube videos saying that branched-chain amino acids make chocolate rivers flow. I mean, you name it, and branched-chain amino acids have been attributed to doing it.  

Now of course the main thing that I’ve been interested in is the anabolic effects of branched-chain amino acids, and we published a paper a few years ago on that. Actually we have one just about ready to be submitted. So yeah, that's been the major focus of it for me, but there are other things, other aspects that we can discuss of claims for the efficacy of branched-chain amino acids.  

[00:08:53] LB: And I think what's interesting about this is on this podcast we’re particularly talking to scientists about their research and how they conduct and perform their research. We often get into the topic of reductionism because that's important for certain kinds of scientific studies. You've got to isolate these things down to their sort of simplest parts so you can understand what's going on. But of course there's a difference between what you're isolating or what you're seeing in the lab because you've had to use a specific supplement because that's what you're testing in your study as opposed to the way in which we should actually interpret that or apply that in the real world. Maybe you could just bring us back to why are we even talking about branched-chain amino acids or leucine and these sorts of things as opposed to just eating chicken or fish? Why has that become the dominant word or words in our vocabulary on this topic? 

[00:09:49] KT: From the perspective of muscle anabolism?  

[00:09:52] LB: Yeah. Absolutely. Yeah.  

[00:09:54] KT: So historically if you go back, branched-chain amino acids in vitro in cell studies have an anabolic effect in the cells, and that's been known since the 70s, at least, and probably before that. And there have been some animal studies suggesting that branched-chain amino acids are important as well. Now people started doing some infusions with humans and stuff and then it wasn't quite as clear. So, infusing branched-chain amino acids.  

Now we should back up and say that of the branched-chain amino acids, which are isoleucine, valine and leucine, the major player is leucine. And of course, over the past sort of 20 years leucine has just really exploded as far as how much attention it's gotten starting with Josh Anthony's studies when he was working with Don Layman in Illinois in rats. Those are studies in rats, and again showing some anabolic potential for those studies. Now I can nitpick those studies because there're some issues with the way that they were designed. But nevertheless, between those studies and the studies of other folks that were doing more cell-based things, you see a lot of emphasis on branched-chain amino acids, especially leucine, as anabolic agents. And the thing about it is is that all the amino acids are substrates. They go into the polypeptide chain that makes a protein. So when your proteins are being synthesized, the amino acids in the appropriate order, based on the messenger RNA and transfer RNAs, come in and make sure you get the right amino acid in the right place, and leucine is part of that. It's part of the chain. But leucine especially, and to a lesser extent valine and isoleucine, are also signaling molecules. They hit the molecular cascades that turn on protein synthesis. And so that's why they've gotten all this extra attention. So they're not only the substrate, but they're signaling and they act as an anabolic agent that way, at least in cells. The thing is as you alluded to earlier, does that translate to humans in vivo? And that's where the discussion comes in.  

[00:11:59] LB: Yeah, and I find this interesting because we very much live in sort of proper pill type culture. I’ve got a headache. I’m going to take this pill to solve the problem. Or now we're talking about COVID. I’m just going to have my vaccine and that's going to solve my problems. And obviously there're differences in mechanisms of action and so on. But what I’m saying is there's a problem and therefore we feel there's a solution for it. It's a pill. It's a vaccine. So in the same way that people are going, “Right. Well, I want to enhance my strength. I want to get bigger, faster, stronger, therefore I’m just going to take these BCAAs. I’m going to pop my leucine threshold so that I’m going to get really big and strong.” But we don't often hear people talking about the importance of the exercise stimulus for example, or the problems that some of these studies have where a correlation has been made but it's a very basic study. They didn't do cell studies. They didn't do biopsies or whatever. Maybe you could just quickly explore that side of this because you pick up your textbooks and eloquently described and explained what amino acids are, essential amino acids, and branched-chain amino acids and leucine and you see how that structured into the sort of the very academic view of muscle hypertrophy or strength and power development and so on. But there's different context behind that, but also that body of knowledge has come from different places over time as you've alluded to. It's gone back some time. How much do we actually know in terms of what actually happens relative to that body of knowledge that exists? I’m not just talking about Twitter or Facebook or whatever, but there are all these published studies, but of course you've just mentioned that there were some issues with some of those studies. So I don't know if I’m over complicating the perspective here, but does that make sense? 

[00:13:59] KT: So you say what actually happened?  

[00:14:02] LB: Yeah. So, I knew I was over complicating this, Kev, and that's the problem. But that's the problem with this. It's very simplistic to go, “Right. I’m just going to take my BCAAs, and I’ve read this research. And, oh, well, I’m probably not eating enough protein so I’m going to bang a bit more of that in and it's problem solved.” But of course it's not quite as simple as that is it? Because you've got issues like the exercise stimulus, maybe the age of the individual, but also our decisions to influence our intake, our quantity, our dosages, etc., of protein or whatever is based on information they've heard from somewhere, right? That's quite a confusing state to be, and I’m not the only one I’m sure.  

[00:14:44] KT: Let me just start with the exercise stimulus. Anybody that's been listening to your podcast regularly will not be surprised to hear me say, because I know Stu says it all the time, and I say it too. The exercise stimulus is the main factor. I mean if you want to get bigger muscles, you can eat all the branched-chain amino acids in the world and it ain't going to help you if you're not lifting, if you're not working out. So that's the main thing.

As far as the way the effectiveness of some of these supplements and things interacting with the exercise stimulus, that might be something to think about. But let's start with – The first thing is if you're supplementing and not working out, then you're wasting your time, money, everything. So let's just assume that this is in an exercise situation and you have that exercise stimulus. So, let me just get to the chase here. Up until about 10 years ago no one had ever actually just given branched-chain amino acids to weightlifters, or of course we tend to use male weight lifters in our studies much to my shame. But nobody had ever done that in male weightlifters, i.e. given them branched-chain amino acids and then measured muscle protein synthesis. And we were sitting around going, “Why hasn't anybody done this?” And so we got some funding to do that study. And all we did was give one group branched-chain amino acids. They came in twice these guys and they exercised, and they got either branched-chain amino acids or a placebo. And so the first thing is we did get a stimulation of muscle protein synthesis. 

Now in this particular study we did the most simplistic study design, and people have listened to the pod we did a few weeks ago on muscle protein synthesis that I talked about the different designs, and you’ve got to think about that. We chose to do the most simplistic one where we just measured it immediately. I mean they exercised. We got them into the metabolic lab and I did the biopsies within 15 minutes of the exercise. Then we waited four hours and they had the infusion going and we waited four hours and did the next biopsy. So, this was an FSR representing that four-hour period.  

So, in the branched-chain trial, the FSR was ~20% or so, a little bit more than 20%, about 22% above the placebo. So, there was a stimulation of muscle protein census by the branched-chain amino acids. But if you compare that to our previous study where we gave whey protein and we chose the amount of branched-chain amino acids that we gave in Sarah's – Sarah Jackman was the first author on that paper. In Sarah's study we gave the amount of branched-chain amino acids that they got in 20 grams of whey protein. And so it was meant to be representative of how much was there. But if you give 20 grams of whey protein after exercise, we were getting sort of a 45%, 50% increase in muscle protein synthesis. So the muscle protein synthesis response to those branched-chain amino acids after exercise was about half or less than half of what we'd see if you give whey protein. And that was consistent with a study a couple of years before that, from Stu's lab, from Tyler Churchward-Venne, and it's consistent with the concept that the branched-chain amino acids have indeed hit that system, hit that molecular pathway and turned it on the MTOR pathway mostly and turned on translation initiation, turned on protein synthesis if you want to think about it that way, or stimulated it more than the exercise.  

And so what happens is you get these amino acids being put into that chain. And so let me use one of these analogies. One analogy I used to use with my students was I’d say if you think about building proteins as like building a wall and the amino acids are the bricks that go into that wall. And so you got the little worker guy and he's building this wall and think about the leucine, especially, but branched-chain amino acids, are coffee, i.e. the caffeine. You hit that worker guy with that. All of a sudden he's working faster and harder and he's building that wall, right?  

So then if you have a complete protein, if you have whey protein, he builds the wall he's got all the bricks he needs and then you build this really nice big wall, right? But if he's only got the branched-chain amino acids, he's stimulated by that coffee and he's building that wall and he's putting those bricks in there, but the bricks that aren't coming from branched-chain amino acids that you ate are the amino acids that are endogenous already in the body and eventually those run low and you start running out of bricks. And so the wall can only get so big. That's what happens in this situation, is you run out of substrate because you're not providing it exogenously like you do with a full intact protein where you get all the essential amino acids.  

And so the other thing that happens too is with branched-chain amino acids, especially if you get higher doses, they compete for the transporters to get into the muscle. So like leucine and isoleucine will compete. And so you may not get as much one as the other in there because of that. And also what you see is – And we saw this in Sarah’s study, and this fits with that analogy. If you look at the arterial levels of the amino acids in the blood, in the arterial blood, which is where you're delivering those amino acids to the muscle with that arterial blood, you start seeing the essential amino acid levels drop, and that's because they're going into the muscle to be utilized and then you're just running out of them and you're not replenishing them with exogenous amino acids like you do if you take in the whey protein. So that's really the gist of why branched-chain amino acids are not effective on their own as an anabolic supplement for muscle building after exercise.  

There is some indication that maybe it's not as critical if you're not exercising. There is some evidence, and I’m not entirely convinced, but there's some evidence that branched-chain amino acids alone might do a little bit better without the exercise, and that's because the exercise also stimulates that wall building and so you run out of those substrates and you need more of those substrates to accomplish it, whereas if you're resting, then maybe you can get away with it a little bit more, but you still don't get as much as if you exercise. So what we're talking about is you need the exercise to build muscle. 

[00:20:35] LB: Sure. And I love those analogies.  You've got the guy building the wall or the girl building the wall, hitting the coffee, caffeine. But so it goes in the real world where it is the person building the wall, you're not paying them enough.  You're telling them to work too hard, etc., etc. And where I’m going with this is you talked about there's some competition that might occur between some of the amino acids there, but how about concurrent training? How about an energy deficit? How about other potential factors that may cause havoc with this, which is something that absolutely must be controlled for in these studies? But perhaps in order to understand those mechanisms, but in the real world there's a lot of complexity, a lot of chaos occurring in someone's average daily living set up. Are there any factors there that should be considered or you think are worth raising at this point? 

[00:21:31] KT: I mean I can't speak to direct evidence about some of those things with branched-chain amino acids, but I don't know why they would be different because the basic physiological concept is going to be there. Concurrent training, I think there's all kinds of controversy as to whether or not you're going to have interference effect and all that kind of stuff. And my take on that is basically it's a volume issue where if you tire out your muscles you can't lift as much. I mean people are trying to make more of it than they should, and I’ve been convinced ever since those studies started coming out in the late 80s. But as far as anabolism goes, I think it's really a matter of you just need to put the work in. And so, if you do, that would be what would be effective. But as far as branched-chain amino acids go, the general concept is going to be the same, that is, if you've stimulated the muscle, the anabolic pathways, the molecular pathways with the leucine, and to lesser extent the others, then you still need those substrates. So, if you're not getting a full protein, then you'd run out of essential amino acids and you can't have an effective muscle building, protein synthesis. So I don't know why that would be different. As far as weight loss goes or something like that – 

[00:22:35] LB: Energy deficit I was thinking more.  

[00:22:38] KT: Energy deficit, yeah. Again, I don't know why the general concept wouldn't apply. It might even be worse in that situation because now you need even more to make up for the decline in protein synthesis. So sure, you want to stimulate those pathways, but I don't see why if you're getting three or four grams of leucine within 25 or 30 grams of protein it's not better because you've got the other essential amino acids, and that's the key to all this is, is that you need those other essential amino acids to provide substrate to put those proteins together. And I don't understand why it would be any different why branched-chain amino acids would be better than a full protein than an intact protein in an energy deficit or following concurrent training or any other situation where you want to increase protein synthesis to the maximal level. 

[00:23:28] LB: Yeah, that's great. And the reason why I’m raising these points is quite simply that it's worth having that discussion when what you're trying to do potentially is manipulate someone's diet, their energy intake to bring about a change in body composition a favorable change in a quality shift in body composition where what we're trying to do is lose body fat, but not lose muscle mass. And in athletes, where we want them to be functional, not just aesthetic improvements in changes in body composition. We don't want to lose that muscular strength, that power, that functionality of course, which is where I guess the attraction of the supplement comes in when you're hopefully not under eating, but you're eating at that threshold where you're minimizing the risk of an increase in body fat, which is of great interest to a lot of people. But of course the other side of that is the risk, the consequences that you may not be achieving a sufficient intake of amino acids in order to achieve this adaptation to training that we're aiming for here. 

So that brings me to the relevance of dose, because you see this talked about a lot whether it's a daily intake of protein, whey, casein, or they talk about specific doses of amino acids or leucine itself. And bearing in mind that people come in all sorts of different shapes and sizes and, well, will as a result have a considerably more varied intake of some of these foods. At what point is the dose actually relevant and at what point do we then start to think, “Okay. Well, maybe there's a case potentially here for supplementation?” 


[00:25:19] KT: I think what we tell people – And again I saw Stu Phillips on Twitter I think it was yesterday, or the day before, saying this again, if you get up into the 1.6 grams per kilo range on a daily basis, and maybe you could argue in situations it could be higher, maybe up to two or so grams per kilo, that the type of protein really doesn't matter. And so those supplements aren't going to really make much difference really, or the type of supplement and all that kind of thing. And of course, I think he was talking about this in the terms of there're big emphasis now on plant proteins and all that kind of stuff. And so, I’ve seen him say this several times and the evidence seems clear to me. I agree, that once you get up into that range it doesn't matter whether you're eating plants or animals or both. 

Now as far as dose goes to get to that range, we generally argue that you want to spread it out through the day. So, then you're talking about getting – if you have four meals and you're trying to get to 1.6, then you want 0.4 grams per kilo for each meal, something like that. Again, I’m sure a lot of your regular listeners have heard this. Most people tend to, if they're not trying, they eat more protein at dinner and much less at breakfast. So, then you're not getting the potentially best response throughout the day if you do it that way. That would be the argument. Stu was involved in a study which showed this very clearly, but that study was proof of concept because it was a 12-hour infusion in a lab and all they ate was protein, 80 grams of protein, throughout that 12 hours. And there are other studies which kind of show data that maybe it's not so clear, although I have some problems with some of the interpretation of those data on those studies. So, I would still argue that for practical purposes to apply this, why not? I don't see any downside in trying to eat a little bit more protein at breakfast and perhaps a little bit less at dinner to get your 1.6. So that would be the kind of dose. 

Now, again, where does a branched-chain amino acid supplement fit in there? I don't see how it does. I don't see any evidence to suggest that you need a branched-chain amino acid supplement anyway for the reasons that we talked about earlier. And so, let me just back up. One of the main reasons that you want to sort of spread it out is this concept that Mike Rennie and Phil Atherton termed the ‘muscle full effect’. I remember back in the day bodybuilders used to tell me they wish they could just have a constant drip of protein in their muscles. This was 30 years ago. But, “Yeah, I just want to have protein coming in all the time.” But that won't work because what you can see happens is if you get amino acids and they stay high in your blood, protein synthesis goes up initially, but the amino acids will stay high and then protein synthesis will drop despite the fact that you still have this high-level of amino acids in there 

Now if you let the amino acid levels come back down and wait a bit and then go back up again, then you stimulate protein synthesis again and it goes up. So you get a better response that way. That square wave of high levels of amino acids in the blood becomes counterproductive. And so you want to have it go up and down. And so then that's why you want to have these meals spread out a little bit to allow the amino acid levels to come back down then you can hit the muscle again with more amino acids. You can get a maximal response that way if you spread it out over the day. That's the theory. Now that's based on supplement studies which a lot of these things that we're talking about are. I mean when I say supplementing, like intact protein throughout the day or something in that study I spoke of. That was Jose Areta’s study that Stu was involved in.  

So, I think that's the argument, is on a dose basis you want to talk about 0.4 grams per kilo four times a day, or maybe if you want .3 four and a half times or whatever to get up to that sort of 1.6 range. But again if you look at all these studies and you look at the typical level that these guys are eating in the studies, well, it's typically around that level. Well, anyway, at least in Britain and the U.S. and Canada and Australia, these kinds of places. So most guys are there. Females tend to be less. Sorry about that. It's reminding me that England and Scotland are playing on Saturday, the women. 

[00:29:25] LB: There you go. So, as I was saying, people get their knickers in a twist and they really do. They get really hung up with the numbers. And like you said the training stimulus, the right type of training have the right and appropriate volume and frequency and all these sorts of things is overwhelmingly important in this consideration. But as I said, people do weird thing – Well, not weird things. People do different things in the real-world, and by that I mean for personal preference or religious purposes or just plain practical reasons they can't eat at certain times of the day. And we have the situation where that maybe they're only eating plant-based proteins or maybe they only eat once a day because that's just the way their lifestyle is or that's their preference.  

Because you've talked about the spreading it out throughout the day, I know we've had people on this podcast over the years talking about MTOR. We've talked about protein distribution. I mean there's all sorts of stuff that – An aging muscle — his original work — we've had that discussed here. But essentially, I guess where one argument people come in with this is they're going, “Well, okay. If I’m a vegan or much older, for one reason or other I might consider taking these supplements to rescue the problem.” What is that situation and what are they talking about when they're saying rescuing the effect? What actually does that mean, Kev? 

[00:30:50] KT: With older folks, of course, you’ve got this concept of anabolic resistance, which I know has been spoken of many times on the pod. And basically those are new. What we're talking about is as you get older the muscle tends to become resistant to the anabolic stimulation from exercise to some extent. I’m less convinced of that, but to protein ingestion. So it's a bang for your buck thing. For the same amount of protein when you're older, you don't get the same stimulation of muscle protein synthesis as you do when you're younger. And so you need more to maximize that response. And that becomes a double whammy because older folks tend to eat less, and I understand why as I get older. It's tougher.  

So then you say, “Okay. Well, you're not eating as much. So maybe we can just give branched-chain amino acids to rescue this.” So we know that you need at least 35-40 grams of protein to get a maximal stimulation because your anabolic resistance, whereas if you're younger 25 grams would do it. But 40 grams is very tough. That's a lot of protein. So older folks may say, “Oh, that's too much. I don't want that much.” So, you give 25 grams and then the branched-chain amino acids to rescue that to get the stimulation up to 40.  

There are some studies suggesting that that's effective in older people and particular with leucine and not necessarily all the branched-chain amino acids, but it's inconsistent. And so I’m not capable at this point of giving you a rundown of why I think it is, but it's inconsistent. It probably has to do with study design and things like that. So it is possible that in an older population that it might be more effective supplement, but I would argue that not a branched-chain amino acid supplement, but an essential amino acid supplement with all the essential amino acids for the reasons that I was talking about earlier. I don't really understand why you would take this.  

Now the argument could be I don't want to take more protein because, A, it's tough to get that in and, B, I don't want the calories. And so you go with the branched-chain amino acids. But you could also go with the essential amino acids and cut down on the calories. Again, with just the essential amino acids, if you have the same amount as in an intact protein, you can get the same stimulation. But you need all the essentials, not just the branched-chain amino acids. So I’m still going to argue that I would not recommend branched-chain amino acid supplements to older people to rescue their anabolic situation if you will. I would say take essential amino acids. And we were doing these studies back in Galveston. In fact one of my papers is one of the first ones to ever show that you get the same stimulation with the essential amino acids that you do with all the amino acids. Although Elena Volpi gets the credit most of the time, but my paper was first and she's just better at marketing than I am. 

[00:33:30] LB: Well, don't worry. We're shouting it loud on this podcast, Kev.  Yeah, and of course older people, they're less active typically. So their energy outputs are lower and that will have an impact on appetite of course, and taste changes and so on and so forth. 

[00:33:47] KT: There's a really good argument, and I’ve made this argument in presentations before that anabolic resistance that older people tend to have, I think a lot of that is because of reduced physical activity and that if you do the work, that the work will overcome a lot of that anabolic resistance, the physical activity, especially weightlifting. And so, I think there's really good evidence that it’s probably not everything. That there is probably some biological decline with age, but you can sure as heck slowdown that slope. I mean you can keep that slope from being so steep by being physically active. And so the first thing I would say, don't worry about your branched-amino acids if you're an older person. Worry about protein but worry about the working out and physical activity, whatever it is. And that's what like my father who's 80, I’ve got him doing tai chi now because he never was an active person throughout his whole life. So he does go to the gym, and I’ve been with him a couple times, really funny. But at least he's doing stuff. I just say keep doing something. That will help keep that slope of that decline less. You don't get to that critical place where you can't get off the toilet on your own.

[00:34:51] LB: Well, speaking of getting off the toilet on your own, Kev, I can't believe you've let us down this path, but people go to the gym and let's say they're having a half decent to decent lifting session two, three times a week, they're still sitting around not doing much most of the time. So I guess the importance of doing something, as you say, doing some exercise as a priority over worrying about supplementing or, “Do I take BCAAs? Do I take essential amino acids?” and so on. If we can just quickly revisit that, because I think that's important because, people, they spend more time talking about this problem than they actually do training in the gym potentially. So it's kind of an interesting situation. Maybe how often – And this is a bit hypothetical. Well, how little a training do you need to be doing for this to be a completely moot point? And I guess flip it the other way is, is this something where you need to be training most days where this becomes more of a critical consideration or is just training two three times a week and eating roughly enough food? Like at what point does this become a conversation that actually has some relevance? 

[00:36:04] KT: I suppose it depends on your goals of course. I think there's plenty of evidence to suggest that regular training is probably the most important thing and that there seems to be – And, again, probably you want to have somebody like Brad Schoenfeld on to discuss this in greater detail because this is –

[00:36:20] LB: We’ve done a whole podcast on muscle hypertrophy. 

[00:36:22] KT: Yeah. So, volume and frequency are – I mean frequency, from what I can tell, seems to be slightly less important, and volume though really can change the response. The total mass that you're moving probably isn't that big a deal from – Especially, in fact, I think I saw Stu tweet a paper the other day. I didn't read it. I just saw the headline. But essentially the bottom line was if you get in there and do stuff, it seems to work, and that if you're lifting really, really heavy, then you're probably not going to be that much better than if you're lifting lighter and doing more. And that's good for older folks of course because you have less chance to get injured and things like that if you're not trying to lift 90% of your 1RM. So you can definitely get a good response. 

If you look at the data for protein synthesis, there was a study done, Mike Rennie's, before he passed away. One of his people did a study. His name was Kumar. He did several different intensities and showed that once you get up to sort of 60% of 1RM, that there's not much difference between that and 78% or 70%, 80%, 90% 1RM as far as the muscle protein synthesis response goes so. And Nick Burd did some work with volume as well and showed that it seems like lighter weights can give you the same kind of anabolic stimulation. So, I think it's more important to just get in there and do stuff. 

Now you probably have to do a little bit more volume if you're doing less weight, but that's okay. I mean it's not that big a deal. If you think about Jack LaLanne, he was famous back when I was a kid because he was this fitness guy well before anybody really thought about it. He used to do all these crazy things, like he swam, I want to say it was in New York –

[00:37:54] LB: Yeah, the Hudson. I remember the story. Yeah.

[00:37:56] KT: He pulled a big ship or something.

[00:37:58] LB: Yeah, it was a big boat, wasn't it? 

[00:38:00] KT: Yeah. All kinds of stuff. Like he had a regular show. Was one of the early shows. But he used to say exercise is king and nutrition is queen and together you get the –

[00:38:10] LB: The kingdom. Yeah.

[00:38:12] KT: And I think that's the way you want to think about it is that nutrition is there to support your workouts and your training. And if you don't do the workout and the training, then the nutrition is not going to rescue, if you will. 

[00:38:26] LB: That's why I get so obsessed with context. People constantly talk about these things without any context really, or they just get so hung up about certain numbers. It all depends, because, yes, it depends on the training that they're doing and it depends on other factors. But if we dial back to a couple of things, when we're talking about BCAAs, which is the sort of topic we're trying to get into here and wrestle with and ultimately arrive at how relevant are BCAAs particularly from a supplemental perspective when there's other things they can consume that contains BCAAs of course. We've done podcasts about muscle protein synthesis and protein balance and breakdown and various other things. If we're going to talk about BCAAs specifically and their potential roles in net muscle protein balance as opposed to, say, specifically muscle protein hypertrophy, would you be having a different conversation with me right now or no?

[00:39:23] KT: You mean whole body protein? 

[00:39:24] LB: Yeah.

[00:39:25] KT: Probably. There seems to be some evidence. Again, some of this evidence goes back to the 70s, that the BCAAs looked like they affect whole body protein breakdown. And in fact in our study, in Sarah's study, Sarah Jackman’s study from 2017, the one I described earlier, we saw evidence for that. So we used stable isotopic tracers and we used one parameter, which is called the rate of appearance, that we can measure with phenylalanine, the labeled phenylalanine, and that rate of appearance, those amino acids are appearing in the blood from protein breakdown, whole body breakdown. And we saw that go – That was lower in the branched-chain amino acid trial than in the placebo trial. We have data that we haven't published yet that the paper is about ready to be submitted. Again, similar thing, in the branched-chain amino acid trial it tended to be lower than the other. In this case it was carbohydrates. So, yeah, I think there is evidence that on a whole body basis that you're slowing down, i.e. ameliorating whole body protein breakdown. 

What does that mean? Well, I don't know, but it should not be automatically interpreted as a good thing, right? That protein breakdown is there for a reason. And if you're just getting branched-chain amino acids, you might be breaking down protein from other tissues to supply amino acids for the muscle because the synthesis is stimulated in the muscle. And so now you're breaking down other tissues to provide amino acids for that muscle. That leads to another aspect of claims for branched-chain amino acids, which is a lot of people have asked me about should I take branched-chain amino acids during exercise so I can stop protein breakdown during exercise? Again, the assumption there is that protein breakdown during exercise is bad, right? Now, maybe, but I doubt it. And how do you know that during endurance exercise that you're not breaking down protein to provide energy, because it does go up. It's only about – It goes from, say, one or two percent up to maybe four or five percent during exercise. The theory is if you provide the branched-chain amino acids and you won't break down as much protein. But maybe you need to break down that protein to remodel it and repair it. And maybe some of that protein is being broken down because you're working hard and you're damaging some proteins you need to break them down to rebuild them afterwards. So not convinced. And of course, you can read about that. And we talked about this what? Was that back in November, December on one of the pods on protein breakdown? That I think it's way, way over interpreted that protein breakdown is automatically bad and we want to stop it. Yeah, I think that's one of the other claims of branched-chain amino acids that I’m not convinced about I don't really see the evidence that it's actually beneficial. In theory it could be, but I don't see the evidence.

[00:41:58] LB: Yeah. Although some people apparently have an opinion on that, but based on what? 

[00:42:02] KT: Oh yeah.

[00:42:03] LB: So I’ve seen it explained in this paper amongst others that you can start to look at some of these things in terms of the sort of a hierarchy with whole food sources of proteins all the way down to leucine, go through the essential amino acids and then the BCAAs and down to leucine. Maybe you could talk about from your perspective, and this is from a practical, people who are genuinely concerned about this topic. For those that have up until now been ensuring that they are supplementing BCAAs. It's added to their whey protein shakes. It's something that they supplement with their regular meals. And by that, I mean BCAAs. There's a hierarchy there, but also there's a hierarchy of relevance as it relates to the impact that these collection of amino acids, these proteins sources will have on things like muscle protein synthesis preventing or ameliorating muscle protein breakdown and so on. As far as the evidence is concerned, and that is from the studies that you feel are the quality studies, not just very basic reviews necessarily, but what is that hierarchy? And it's skewed in which direction in terms of from a practical perspective what she would be doing, Kev?

[00:43:25] KT: Well, I mean in the paper, and I think Daniel put this hierarchy in there, and I pushed back a little bit against it because I don't know that it's clear. Of course, as you say, the hierarchy would be that whole foods are better than intact protein supplements, but intact protein supplements are better than essential amino acids, protein – Or essential amino acid supplements which are better than branched-chain amino acids, supplements which are better than leucine. Now I’m not sure that that's true. You could make an argument that you would want just leucine rather than all three branched-chain amino acids alone because you won't get the interference effect, but you still get the stimulation from leucine. So I’m not convinced about that. 

As far as the whole foods go, generally we tell practitioners and practitioners tell their athletes, “Hey, we want to do food first. That's absolutely true from the standpoint of how much things cost,” and it's a lot more pleasant to eat a nice piece of chicken than it is to – Oh, well, maybe some people don't think this, but to drink a protein shake or whatever. From a metabolic standpoint, yeah, there is some evidence now. It's emerging. And people are starting to do more studies with whole foods as far as muscle protein goes. And there's now some evidence, and I think we talked about this last time about this matrix, this food matrix, their interactions with other nutrients that might be happening so that you don't get that with an isolated protein. And so that would be the argument for whole foods. 

You mentioned leucine threshold a couple times. That's the concept that you need to hit this leucine threshold, i.e., a certain level of leucine in the blood, before you get the maximal stimulation of protein synthesis. The problem with that is there are ample studies showing that that's not true, that you get maximal stimulation without in a situation where the leucine doesn't go as high. Now maybe that's because leucine threshold is much lower than they think, but the higher the leucine goes doesn't necessarily translate into the greater the protein synthesis. So, leucine threshold seems to work if it's isolated proteins in liquid supplements. Then it tends to be pretty consistent. But as far as foods and other proteins go, it doesn't stick. 

So there seems to be something food, and more studies need to be done, and they are. They're being done. And of course, we talked about the milk study that we did back 15 years ago and then the egg study which was done a couple years ago in Nick Bird's lab, and both of those suggest that there's something to that whole food that's more than just the protein in that food. That would lend credence to the fact that the food is at the top of that hierarchy. And the reason the protein, isolated protein, full proteins are intact is because what we said right from the beginning which is they provide all essential amino acids and they provide the leucine. And then the same for the essential amino acids, they give you all essential amino acids and leucine. And you could make the argument that those are just as good as the protein, the intact proteins. I think that your context needs to be put in before we start talking about that hierarchy being absolute.

[00:46:15] LB: Completely agree. It's just that's what people do. That's the argument, isn't it? “Oh, this is better than that.” And the other side are going, “No. BCAAs are everything.” And I think when we position the supplement as some sort of ergogenic aid where I’m taking this because it's going to optimize the adaptations that I get from my training, for the purposes of enhancing strength and hypertrophy I guess is the ultimate question. Based on all the evidence, what we know, will supplementing BCAAs have any meaningful impact on strength and hypertrophy I guess is the basic question, isn't it? 

[00:46:58] KT: If you think about the word supplement, what you're saying is supplement is you're taking this on top of what you're already doing. It's adding to it. It's supplementing. It's not substituting.

[00:47:10] LB: Yeah, it's not substituting.

[00:47:11] KT: I really don't see any evidence that you need supplements at all as far as metabolism and that goes. Practically, maybe, because then it becomes a substitute. As a substitute I think it could be important for certain populations. If you're you know an NCAA athlete in the United States, you're a collegiate athlete and you’ve got training in the morning and then you’ve got classes and then you’ve got training in the afternoon. And so, you're struggling to go and eat a proper meal. Then maybe a protein shake or protein bar or whatever might be a good way to sort of supplement, a substitute for what you're not eating. But if you can eat, I would argue that you're better off doing that. I think a lot of practitioners anyway tend to want to do that, right? They want to do food-first all the time.

[00:47:55] LB: Yeah.

[00:47:56] KT: I agree for lots of reasons. Yeah, but I still think that it's not branched-chain amino acids, which is the answer. I think it's overwhelming the evidence that you're better off with an intact protein, which is cheaper. Maybe they're better now, but I’ve never tasted a branched-chain amino acid supplement that you didn't have to just sort of hold your nose and get down despite whatever they're trying to mask the taste with. 

Yeah, I don't get it. I don't I really, really don't see any reason to recommend branched-chain amino acid supplements to anybody. There might be an argument for in certain situations in an older population you might think about leucine. That would be if you don't want to add in lots of calories with protein or they can't tolerate lots of protein, but you can give them a little bit of leucine. Again, it tastes terrible, but there could be an argument for that. I think there still needs to be more work done because the evidence is inconsistent. But no. If you don't get anything else out of this pod. The message is -  branched-chain amino acids are just a waste of your money. And there are other rationales and suggested uses of branched-chain amino acids. We haven't touched on central fatigue. Or we did a study with muscle soreness one time. It looks like branched-chain amino acids might actually ameliorate muscle soreness after exercise. We did it and a couple other people have done. It looks like there's something there. What does it mean? I don't know. But I’m still not convinced in a practical setting that that's worthwhile, because when you do these muscle soreness studies they're so artificial that you don't know where they're going to come in in a real life situation. You take people and you just really kill them and they can barely walk, and it's just not something people do very often if ever. 

[00:49:34] LB: Well, that’s it. Isn’t it, Kev? The thing is, is that the mindset of the consumer is, “Look, I want to be stronger and I want to have bigger muscles and/or I’m going to diet down and I don't want to lose all my muscle because I want to look good on the beach whenever we're allowed to go onto a beach that is,” or for the physique athletes out there who are a bit more serious about all of this. That's where the desire to do whatever it takes to not have their muscles drop off so to speak is where a lot of this comes from. And sort of the purveyors of the myth tend to be the people that market this are the people that are selling the supplements. And I think it's quite clear that maybe you should be buying potentially some of their other products that has evidence behind them like whey protein or whatever, but not BCAAs particularly in the context of things like strength and increasing muscle mass. 

Listen, Kev, we were thinking this might not be more than a five-minute conversation, but I’ve managed to try and sort of act for what I feel is the people that don't quite get it. So I’ve deliberately taken that perspective in this conversation because I think it's fascinating that we can have an hour or so discussion about this topic when so many people think it's a fact, BCAAs are great, or you've got the other camp who say no, but you know you don't get this depth of conversation in a tweet. So that's why I think there's some value behind this. 

Listen, Kev, I think we'll wrap up the conversation. Is there anything you wanted to leave the listeners with on this whole topic just by way of, I guess –

[00:51:12] KT: I’m going to use my American football analogy that I heard Bob Wolfe use one time, and it was with leucine. It was similar to the one I use, but I know some of your listeners might not be terribly familiar with American football, but the quarterback is critical position and much more critical than in proper football and/or rugby in any particular position. It's just an outsized influence on that game, on that sport. And so, leucine is the quarterback, and sort of runs the show, and the other essential amino acids are the other positions and you need those other people because the quarterback on his own can't score a touchdown. 

[00:51:48] LB: It’s team effort, Kev. That's what you're saying.

[00:51:49] KT: Right. And I was looking for a place to stick that analogy in there so I have to artificially put it in at the end.

[00:51:56] LB: There you go. Well, thank you, Kev. I always enjoy having these conversations with you and I’m sure our listeners will have gained a lot from that chat and we'll bring back many more of these podcasts where we're going to tackle very specific topic areas that you have this huge depth of knowledge and experience with. So if the listeners want to contact us via the IOPN website, then feel free to prompt us with some topics you feel that we could have a good conversation about that you feel would be of value to the listeners of this podcast. But we'll call it a day. Thank you very much for your time, Kev, and we'll catch up again very soon. 

[00:52:38] KT: My pleasure. Look forward to it.

[00:52:40] LB: Take care everyone. Bye-bye.