Dr. Edward Coyle's Defining and Controversial Work on Endurance Athletes

Pick up any recent exercise physiology textbook and there’s going to be a nicely drawn graphic showing how we use carbohydrates and fat for fuel along with an equally detailed graphic showing the physiological attributes needed to perform as an endurance athlete.

But there was a time when this information wasn’t in the textbooks because researchers still had to figure it all out. How important is VO₂max? Can we improve efficiency? And how much do we rely on fat for fuel? These were all questions that hadn’t been fully answered when Dr. Edward Coyle began his career, but over several decades he became one of the seminal researchers answering these questions.

In this episode, hosts Rob Pickels and Trevor Connor review three of Dr. Coyle’s most well-known studies, including his most cited which dives into how our muscles use various sources of carbohydrates and fats for fuel. We all know that our muscles use a mix of these two nutrients, but what was truly novel about this study is how our muscles balance using the fuels already in the cells versus what’s supplied in our blood.

Next, our hosts will shift to a 1999 review where Dr. Coyle tries to take his decades of research and create a chart of all the factors that contribute to performance—including what he calls morphological components and functional abilities. In this study, Trevor and Rob point out how Dr. Coyle was thinking through these factors in real time and how it ultimately became a graphic (below) that laid the groundwork for the summary graphics found in most exercise physiology textbooks.

Finally, our hosts dive into a 2005 study that is perhaps Dr. Coyle’s most well-known and controversial, as it ended up at the center of the most famous doping scandal in professional cycling history. Dr. Coyle collected data on a many-time Tour de France champion, from when he was a U23 rider until after his first win, and offered his assessment of how this rider became the best in the world. Both the quality and ethics of his results have been challenged since. Our hosts finish the episode by exploring the science and controversy of this infamous study. It’s not one to miss!

Also, one quick correction. We got our dates mixed up in discussing the final study. The year it was published and the controversy at the center of it occurred in 2005, not 1999.

So get ready for a little controversy, and let’s make you fast!

From: Coyle, Edward F. 1999. “Physiological Determinants of Endurance Exercise Performance.” Journal of Science and Medicine in Sport 2 (3): 181–89. https://doi.org/10.1016/s1440-2440(99)80172-8.

References

Coyle, Edward F. 1999. “Physiological Determinants of Endurance Exercise Performance.” Journal of Science and Medicine in Sport 2 (3): 181–89. https://doi.org/10.1016/s1440-2440(99)80172-8.

Coyle, Edward F. 2005. “Improved Muscular Efficiency Displayed as Tour de France Champion Matures.” Journal of Applied Physiology 98 (6): 2191–96. https://doi.org/10.1152/japplphysiol.00216.2005.

Holloszy, J. O., and E. F. Coyle. 1984. “Adaptations of Skeletal Muscle to Endurance Exercise and Their Metabolic Consequences.” Journal of Applied Physiology 56 (4): 831–38. https://doi.org/10.1152/jappl.1984.56.4.831.

Hopker, James G., Damian A. Coleman, and Jonathan D. Wiles. 2007. “Differences in Efficiency between Trained and Recreational Cyclists.” Applied Physiology, Nutrition, and Metabolism 32 (6): 1036–42. https://doi.org/10.1139/h07-070.

Joyner, Michael J., and Edward F. Coyle. 2008. “Endurance Exercise Performance: The Physiology of Champions.” The Journal of Physiology 586 (1): 35–44. https://doi.org/10.1113/jphysiol.2007.143834.

Moseley, L., J. Achten, J. Martin, and A. Jeukendrup. 2004. “No Differences in Cycling Efficiency Between World-Class and Recreational Cyclists.” International Journal of Sports Medicine 25 (5): 374–79. https://doi.org/10.1055/s-2004-815848.

Pinot, Julien, and Frederic Grappe. 2014. “A Six-Year Monitoring Case Study of a Top-10 Cycling Grand Tour Finisher.” Journal of Sports Sciences 33 (9): 907–14. https://doi.org/10.1080/02640414.2014.969296.

Płoszczyca, Kamila, Jakub Foltyn, Jakub Goliniewski, Janusz Krȩżelok, Stanisław Poprzȩcki, Mariusz Ozimek, and Miłosz Czuba. 2019. “Seasonal Changes in Gross Efficiency and Aerobic Capacity in Well-Trained Road Cyclists.” Isokinetics and Exercise Science 27 (3): 193–202. https://doi.org/10.3233/ies-192115.

Romijn, J. A., E. F. Coyle, L. S. Sidossis, A. Gastaldelli, J. F. Horowitz, E. Endert, and R. R. Wolfe. 1993. “Regulation of Endogenous Fat and Carbohydrate Metabolism in Relation to Exercise Intensity and Duration.” American Journal of Physiology-Endocrinology and Metabolism 265 (3): E380–91. https://doi.org/10.1152/ajpendo.1993.265.3.e380.

Episode Transcript

Trevor Connor 00:00

Trevor, hello and welcome to fast talk. Your source for the science of endurance performance. I’m your host. Trevor Connor, here with Coach Rob pickles. Pick up any recent exercise physiology textbook, and there’s going to be a very nicely drawn graphic showing how we use carbohydrates and fat for fuel, and an equally detailed graphic showing all the physiological attributes needed to perform as an endurance athlete. But there was a time when this information wasn’t in the textbooks, simply because researchers still had to figure it all out. How important is VO two, Max, can we improve efficiency? And how much should we rely on fat for fuels? These were all questions. It hadn’t been fully answered when Dr Edward Coyle began his career, but over several decades, he became one of the seminal researchers answering these questions. In this episode, Rob and I review three of Dr Coyle’s most well known studies, including probably his most cited, which dives deep into how our muscles use the various sources of carbohydrates and fats for fuel. We all know that our muscles use a mix of fat and carbohydrates, but what’s truly novel about this study is how our muscles balance using the fuels already in the muscle cells versus what’s supplied in our blood. Dr Coyle came up with a very novel way of solving this question. Next we’ll shift to a 1999 review where Dr Coyle tries to take his decades of research and create a chart of all the factors that contribute to a performance, including what he calls morphological components and functional abilities. In this study, you can see him thinking through all these factors in real time and ultimately coming up with a graphic that laid the groundwork for the beautiful summary graphics found in most exercise physiology textbooks. Finally, we dive into a 2005 study as perhaps Dr Coyle’s most famous and controversial as it ended up at the center of probably the most famous doping scandal in professional cycling history. Dr Coyle was able to collect data on a many time winner of the Tour de France from when he was a U 23 rider until after his first win, and offer his assessment of how this rider became the best in the world. Both the quality and the ethics of his results have been challenged. Rob and I finished the episode diving into the science and controversy of this study. It’s not one to miss. Also, one quick correction we got our dates mixed up in discussing the final study. The study was published, and the controversy that was at the center of it occurred in 2005 not 1999 so get ready for a little controversy, and let’s make you fast. Well, Rob, we haven’t done a seminal episode in a while, so good to get back to one. Love doing the research. We picked Dr coyola For this one, and you were just looking him up. So what do you have to say about his background?

Rob Pickels 02:36

1982 that’s what I have to say. The year I was born was the year he started teaching at University of Texas in Austin, which makes him there for what am I? 42 years old? 42

Trevor Connor 02:48

years you were born in 82 Yeah, man, you’re younger than my brother. Okay,

Rob Pickels 02:53

good. I’m younger than a lot of people and some other ones. I don’t know where to go with that. I just, I want to talk about Dr Coyle and not but, yeah, you know, this guy has been around. He’s been, you know, supervising professor, involved with a lot of really well known researchers, meaning he’s sort of trained to the next crop of people that we’re hearing from today. And you know, his research has been foundational for a lot of what we understand. And oftentimes, though it is funny, sometimes I look at the dates of these research studies, and today I think we have one from 93 one from 99 one from mid 2000s Yeah, in some regard, it seems like so long ago, and in other regards, it seems like it really wasn’t that long ago. And so we’re making some pretty major discoveries and understanding of how the human body works, of how exercise, improvement and adaptation occurs. And really it was, it was in the last 20 years, right? That we’re learning some of this stuff. So pretty incredible, but really excited to talk about Dr Coyle today. I think it’s gonna be a good one. Yeah,

Trevor Connor 04:01

so Dr Coyle has pretty much spent his career at the University of Texas in Austin. And when you talk about kind of the meccas of exercise physiology, that is definitely one of them. You look at the names that have come out of there, Dr Andy Coggin works with Dr Coyle, Dr Seiler, went to school there. There’s a lot of big names that came out of that. University

Rob Pickels 04:26

sure is, and this isn’t really the first time, well, maybe it is the first time we’ve talked about Dr Coyle, but you talked with Dr Coyle back on Episode 146 when you discuss cardiac 46 146 far back. That feels like a long time ago, right? Yeah, no, it

Trevor Connor 04:44

felt like I just did that, like a year or two ago. I guess it was a while ago. You guys,

Rob Pickels 04:48

you talked about cardiovascular drift, and I wasn’t a part of that episode. And so I’m actually, I’m gonna go back and listen to it. I’m sure it’s a good one. Yeah?

Trevor Connor 04:55

Well, we’ll put the link in the show notes. So yeah, going to your point about. And if you look at the dates, and it looks like a long time ago, but in other ways, it doesn’t feel like that long ago. The thing I found really interesting is, you buy an exercise physiology textbook nowadays, and like very basic exercise physiology is going to have all the you know, when you consume carbohydrates, here’s the whole process, here’s how they’re used. When you’re at intensity, you’re using glycogen, plus this much glucose. I mean, it’s all figured out. Same thing for fats. You can read all the very nicely laid out. Here’s what happens with fats when you consume here’s what happens at different intensities. Dr Coyle was doing some of his best research at the time when we didn’t know all this, right? And so you read this study, and these, some of these studies, in some ways, you go, Well, I knew all that, but you have to remember, at the time, they didn’t know, yeah, didn’t know all that back in 93 you’re basically reading the studies where they figured this out. And that kind of makes it fun. It kind of makes it neat to go back and read this, right? Yeah,

Rob Pickels 06:02

so Trevor, you know, let’s kick it off with this first one. And for full transparency, when, when we do parity, for full transmorphic occasion, yeah, for full coffee

Trevor Connor 06:14

is right there. You might drink a little more of

Rob Pickels 06:16

For full trans parity, that’s a word, right? Transparency. Holy,

Trevor Connor 06:23

there you go. Wow.

Rob Pickels 06:24

I honestly thought the transparency was a was a word. For a moment, I

Trevor Connor 06:29

want to look it up. It sounds like it should be a word. It should be, I bet you it is.

Rob Pickels 06:33

That’s, that’s, that’s, I am so smart. S, M, R T, sorry, Simpson’s reference for you people born in 1982

Trevor Connor 06:41

keep going. I’m looking this up. Okay,

Rob Pickels 06:43

you know, Trevor and I, we pick a researcher who has had great influence, and then we look back through their studies. We try to get maybe some research that represents different times of their career or different topics, or whatever else. And in this one, I just want to say, you know, Dr Coyle wasn’t necessarily the first or the last the supervising author. He was a second author on this paper, and it was a DR Roman, R, O, M, i, j n, that was the first author. But this was regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration. Again, something that seems, I don’t know, maybe it’s not well understood now, right? But it feels like a really simple topic, but they really dived into it. And they dived into it on Trevor by looking at the metabolism and by understanding a little bit deeper, not just using the indirect calorimetry that we normally use, right? That’s when people collect breath by breath, oxygen and CO two values. But they also use some some tracers, some stable isotopes,

Trevor Connor 07:43

yeah, and I think that’s really important, by the way. Before I go, there not a word, not a word, but transparity is a leader in Microsoft technologies. Well,

Rob Pickels 07:52

there you go. Don’t really like Microsoft or Microsoft products, although I use OneNote. Onenotes, great.

Trevor Connor 07:58

OneNote is great. That’s where I keep everything. So I actually found it really interesting. I’ve seen this with some of these older studies, where you have the elements that we all know, and you see again and again and again the research, but there were some elements in this study that we’ve just kind of forgotten about, that to me were some of the most interesting parts. And as you said, it was because they used the stable isotopes. Yeah. So when you do indirect telemetry, that’s where you see somebody on the bike with the mask, and they’re measuring vo two and VCO two, and they can figure out what’s the ratio of fat to carbohydrates. We all know that with increasing intensity, your body uses more and more and more glucose for fuel and becomes more reliant on it, where you have more of that parabola with fat, where, up to moderate intensities, you’re using more and more fat for fuel, hopefully, and then, yes, hopefully. And then as intensity gets fairly high, you actually start using less fat for fuel, and you’re pretty much relying on glucose. That’s established, and we’ve known that for about that for a while. But they wanted to get deeper into this. They wanted to say, Look, you have plasma. Your muscles can pull fat and glucose out of your blood, out of the plasma, but it also has intramuscular stores. You have glycogen, and you do actually have some stored fat in your muscle tissue. And so they wanted to see, how does that work? What’s the balance between those and either, I’ve saw that a long time ago when I was studying this and school and just forgot, but reading, I was like, man, you know, I just, I don’t remember ever seeing this, right? And it was kind of exciting, yeah.

Rob Pickels 09:42

And so these tracer isotopes, if, if I remember right, it’s kind of like, you know, there are radioactive materials that break down over time. This is an isotope of they used glycerol and palmitate that were stable. There’s no radioactivity there. But because. The molecule is different. They’re able to measure it at the end and say, well, here’s glycerol, but it’s the labeled glycerol, so we know that it came from the infusion, and it can help them sort of back, calculate exactly where we’re pulling from, and understand that metabolism a little bit deeper,

Trevor Connor 10:17

right? Which is kind of neat. So another example of that is you can label a glucose molecule. Actually, can you label a glucose molecule?

Rob Pickels 10:27

I’m sure that you can, but they did not use labeled glucose in this they were able to look at blood glucose.

Trevor Connor 10:32

But so, for example, you can, you can label a glucose molecule and then put it into the body, and then you start measuring the output. So the end products of oxidative metabolism are your CO two and water. And you can see, hey, you know, was it fully oxidized by looking for those markers right in the end products. So one important thing to point out here, and this is a big part of the paper, they had to make a lot of assumptions. So they’re using these stable isotopes, but then a lot of calculations are involved to try to figure out exactly how fuel is being used. So, you know, they label the glycerol, but they have to make the assumption that all glycerol that they then measure in the blood comes from triglyceride breakdown. So triglyceride is just three fatty acid molecules bound to a glycerol. So if you use those fatty acids to produce energy, you could just end up with a glycerol molecule that your body will then send back to liver or adipose tissue and produce another triglyceride. So they had to make the assumption that all that glycerol comes from the breakdown of triglycerides, and that there’s no breakdown of the actual glycerol molecules. You know, another assumption that they made was that all glucose was being used for fuel. And these are they admit big assumptions. And what they kind of say is, you know, that’s not 100% true, but there’s not enough of these other weird things going on to be physiologically significant. But the question is, can you really say that? Right? So I think really, the there were a lot of things that they discovered in this study. So let’s put those assumptions aside, and let’s say for the most part, you can buy those assumptions based on those there were a lot of interesting discoveries. But I think the biggest thing that they point out, where they start, is that with glucose, it’s fairly simple increasing intensity. You use more and more glucose for fuel. It’s just that simple. It’s not that simple with fatty acids, with fatty acid consumption. So they certainly saw the you don’t use much at low intensity. Use the most kind of that moderate, 65% intensity. And

Rob Pickels 12:49

just within perspective, we’re talking about sort of a base zone, one, one and a half, maybe two millimoles of lactate, yeah.

Trevor Connor 12:57

So six. So they have it. We should have mentioned this. There’s three intensities that they use, 25% of VO, two, Max, 65% and 85% right? So 65% is that solid. Zone two, ish type ride, maybe high. Zone 120, 5% is noodling. That’s a slow walk. It’s

Rob Pickels 13:16

not even active recovery, yeah, exactly

Trevor Connor 13:18

85% is anaerobic threshold, maybe

Rob Pickels 13:23

even higher. They said. They said that the subjects could only maintain it for 30 minutes, right? And they needed 20 minutes of of steady state so that they could do their measurements. So that seems like it was like the highest workload they could get someone to do, which is important, because they measured the 25% and the 65% vo two max for both 30 minutes and 120 minutes. So they also looked at a duration time, course, and obviously they weren’t able to do that at 85% because literally, nobody could ride that low, right? So,

Trevor Connor 13:57

you know, going back glucose was simple. As you went up the intensities you’re using more and more, barely touching it at the 25% you’re almost completely relying on fat. Fat. You saw the most usage of fat at the 65% less at the 85% but the other thing you saw with fatty acids is it gets a lot more complicated. Yeah.

Rob Pickels 14:19

Trevor, something that was interesting to me was that based on their glycerol, right? And you talked a little bit about some caveats there, but based on the glycerol, there appeared to be an increased call for free fatty acids that increased with each exercise intensity. So even though we have stated you’re not using much fat. At 85% the body was still trying to liberate it through a process called lipolysis, right, the cutting of fat, lipolysis. So that lipolysis was potentially occurring, but we weren’t getting it, perhaps, into the bloodstream. And they came to that conclusion because. So in the 25% in the 65% vo two Max conditions, as soon as somebody stopped exercise, the rate of appearance of these free fatty acids in the blood decreased. Okay, exercise is done. We don’t need much fat anymore to fuel that exercise. But in the 85% as soon as somebody stopped exercise, there was a big flood of free fatty acid into the bloodstream, and they hypothesized that there might have been lipolysis that was occurring, but for some reason, the free fatty acids weren’t able to get out of the adipocyte and into the bloodstream and to the working muscles.

Trevor Connor 15:38

Right? So it’s a fascinating graph to look at, like you look at the 85% intensity, you look at glucose usage, and just boring straight line. But at the 85% as you pointed out, in the first couple minutes, you actually see a drop in the available free fatty acids. And then at the end of the exercise, it just shoots the sky way back up, yep, and then slowly comes back down. And they also pointed out, as you said, that the lipolysis exceeded what was being used, yeah. So the body’s trying to keep up, but it just looks like it can’t get these free fatty acids to the working muscles. And you know, some of their explanations for that were, one, there’s less blood flow to the adipose tissue because you’re trying to get oxygen to the working muscles correct, which is more important. The other issue is free fatty acids can’t just be completely free. In the blood. There’s triglycerides. They need to be bound to something called albumin, and so there’s a question of albumin availability. So basically, what you’re just seeing is our body’s ability to get the fats to the working muscles just isn’t that good, correct? And

Rob Pickels 16:50

you know, hey, it might be worthwhile to put your body’s effort somewhere else, like you were pointing out. We don’t need blood flow to the adipocyte. We need blood flow to the skin for cooling. We need to get oxygen to working muscles. And so even though, you know, maybe it would be in more efficient in some aspects to liberate those fatty acids and the whole scheme of things, in the big picture, not beneficial.

Trevor Connor 17:12

Yep, it’s the good old we have enough blood in our system to do some things, just not to do all things, right? And so you have the the similar issue of, when you’re going really hard, blood flow to the gut shuts down, because your body’s assumption is, if you’re going that hard, you don’t care about eating right now, you’re probably trying to survive. Yeah,

Rob Pickels 17:32

it’s interesting, too. Nowadays, in 2024 all the rage is on multiple transportable carbohydrates. 90 120 or more grams a minute. And in this study, they’re still in that era of 30 to 60 grams a minute.

Trevor Connor 17:50

Was it was this study or the next study where he’s talking about trying to get 40 to 60 grams? I think it

Rob Pickels 17:55

was, I think it was that. It was the next one that we’re going to talk about, yeah, but, but they do talk about that a little bit in this one. And you know, Trevor, I think that we both thought some of the some of the glucose changes were interesting. You want to dive into that.

Trevor Connor 18:10

Yeah. So he has a really good graph in here that I think summarizes so much of what they try to talk about. And like I said, this is where it gets interesting. Is looking at the plasma sources of free fatty acids and glucose versus the what’s already in the muscle. So muscle source of glucose is glycogen, and you also have muscle triglycerides that you can break down. And what you see is at the low intensity, you are getting almost all of your energy from plasma sources. You’re just not dipping into the muscle sources at all. The other thing you’re seeing is primarily your fuel is just the free fatty acids that you’re pulling out of the blood, because you’re just not going very hard. So there isn’t a blood delivery issue. You can get what you need, and it just gets supplied. As you get to 65% what you start seeing is a greater reliance on the muscle sources of both glycogen and triglycerides, and that’s where you see the greatest usage of the muscle triglycerides. And you’re starting to see an increase in the plasma glucose usage. And then when you get to 85% you know your biggest fuel

Rob Pickels 19:25

source is glycogen, two thirds muscle glycogen. Yeah, yep. Now,

Trevor Connor 19:29

what’s really interesting, so this is based on calories, is you look at total calories coming from combined plasma, free fatty acids and glucose. It is the same across all three intensities you’re getting about, yeah, 80 calories per kilogram. Yeah, about that range, yeah, yeah, kilograms per minute. Knows that’s a small c, not the big K, yeah.

Rob Pickels 19:54

For what it’s worth, the the vertical axis on this is in increments of 100 so Trevor’s guess of 80 is. Is pretty close, I’d say,

Trevor Connor 20:01

but it is exactly the same. So no matter how hard you’re going, you’re getting about the same amount of calories from blood sources. Now at higher and higher intensities, is more and more plasma and glucose than free fatty acids, but combined, they’re about the same. So as you increase intensity, you’re getting those extra calories from muscle stores. Yep,

Rob Pickels 20:24

yeah. And I think that this is interesting, because our ability to transport energy in the form of both glucose and free fatty acids is somewhat limited through the body. And this is a concept that we’ve brought up before, but if people haven’t heard it. You know, essentially, carbohydrate, when it’s stored in muscle, it’s locked in the muscle. The carbohydrate in your thigh can’t go to your tricep. Doesn’t work that way. But carbohydrate that’s stored in the liver is able to actually leave the liver, hit the bloodstream, and go anywhere in the body that it’s needed. But we’re very limited in the amount of calories that we have in carbohydrate. It’s going to say that it’s around 400 it’s going to vary a little bit depending on, you know, the size of your body and how carbohydrate loaded you are, but that’s only 400 calories, and we know you can cruise through 400 calories very quickly. So if plasma glucose was your biggest source, you’d be running out of fuel immediately. So it’s almost like this dose metered relationship that’s occurring, yep. Now

Trevor Connor 21:32

I think the other interesting thing that they show, based on everything that we’re just talking to you about, is at those high intensities, you’re so reliant on what is inside your muscles that store isn’t very high. This is why you just can’t do those sorts of intensities for very long, you’re going to start depleting those energy stores. And that’s why they couldn’t do the two hours at that sort of intensity, because what you saw at 65% and 25% is they had them hold that for two hours because they wanted to see the effects over time. And what you saw over time was initially using a lot of the intramuscular stores, and then, because they’re depleting that, becoming more and more reliant on going back to the plasma source, becoming more reliant on that over time, correct? But that high intensity, you’re gonna deplete the intramuscular stores before you really have that option to replace that with the plasma stores. Exactly

Rob Pickels 22:27

right. So to recap, that when we talk about the contribution at 2565 85% initially, we’re talking about kind of at the onset, or 30 minutes into exercise, is when they measure it 30 minutes. But no matter what we say there as exercise length, duration increases. You run out of your stores, in your muscle, and you have to rely on plasma. Doesn’t matter what intensity you’re at, everything shifts to plasma over time.

Trevor Connor 22:59

Yep. So believe it or not, as complex a study as this is, I think we kind of hit the main points. Is there anything else that you can think of that we need to discuss? Oh, boy, I’m

Rob Pickels 23:09

sure there is.

Trevor Connor 23:11

I’m looking at my notes today. I have a ton of notes on this study. It’s a I love the studies from back in this time, where they would let them go four or 5000 words and just go deep into this

Rob Pickels 23:22

stuff. Yeah, duration did not have much of an effect at 25% that’s true, but it did at 65% so when you’re out there and you’re not really doing anything like literally, like meandering around the block, we don’t necessarily see the shifts that we talked about. But I will say, Trevor, I think that everything you just said holds true, because the vast majority of people are going to be working at that 65% and, you know, or higher. And so I do think that that relationship with duration holds true. So, yeah,

Trevor Connor 23:52

I just want to emphasize how slow 25% as like this had to be done on a trainer, because they sent you out on the road and said, Stay at 25% max. You might fall over.

Rob Pickels 24:04

I’m pretty sure it was on a Monarch bicycle pedaling at 80 rpm. Yep.

Trevor Connor 24:08

So you know, to me, the key message with this study, and this is one of the most referenced studies that Dr Coyle has been part of, is, this is at the time when we were, I shouldn’t say we I was a kid.

Rob Pickels 24:25

When they I was 11, yeah, there you go. 93 Yeah, I was 11. They

Trevor Connor 24:30

were still figuring all this out, like this. This was pretty groundbreaking stuff, of figuring out, how does our body use carbohydrates and fats at these different intensities? You know, how are we using plasma versus intramuscular stores? This would have been a very, very exciting study at the time. Yeah, you

Rob Pickels 24:49

know, Trevor, if we move on to the next one, which was a measly six years later, I’d say that this paper that Dr Coyle wrote, he wrote this by himself on. 99 it was in the Journal of Science and medicine and sport. I think he has a lot of things figured out at this point. You know where this paper titled physiological determinants of endurance exercise performance, is the culmination of a lot of these other earlier research studies that he’s done, and now he’s attempting to put together a model of endurance sports performance, and this is definitely one. I’m going to encourage everyone check out the show notes. Head over to fast talklabs.com you have to see the visual the chart that he has in here, because that chart is the entire reason that I propose this paper be part of the episode exactly because, you know, and we’ll talk more in depth here, but this chart ultimately lays out, hey, performance velocity is here, right? How fast you’re traveling over ground, how fast you’re riding your bike. These are all of the things that play into it, resistance to movement, your lactate threshold, power, what plays into that? Oh, your stroke volume plays into that. And it’s this big, large visual model. And for me, it emphasizes the fact that we oftentimes spend so much time on the minutia, right? You know we’re talking about P, P, A, R, and, you know, everything else, all of these agonists. And sometimes we need to step back from the minutia, and we need to look at the big picture and say, How does all of this stuff fit together? Why do we even care about muscle capillary density, right? Why do we care about mitochondrial density? All we do is talk about, how do we improve mitochondrial density, but so what? What does that affect? This paper lays out that big picture of how interconnected all of these measures and morphological considerations are.

Trevor Connor 26:48

Yeah, what I was surprised about by this review was a how short it was. I know it was a very short review, but as you said, the visual told a lot. All

Rob Pickels 26:59

you need is figure two. It could have just been the figure two and no words,

Trevor Connor 27:03

but you can really see in it that this is him taking probably a decade and a half of research that he had done before that. And it’s him trying to pull it all together into what does this mean? Yeah. And so you even see, in some ways, I thought it was written as a obviously, he probably went back through it multiple, multiple, multiple times. But you can see very much that it’s it’s him figuring things out, how to pull all this together and what are all the key pieces. It actually reminded me, we just did an episode with Dr Seiler, who did a review talking about everything that he’s learned about, about high intensity interval training. And you saw in his paper a lot of the thought process. You saw him go on these tangents, like breathing rate and then coming back to the main topic. And there was a bit of that here, where he starts the paper by talking about, you know, the two biggest things that impact you are heat and acidosis. And then, you know, starts to talk about those. But then goes, now, let’s talk about all the things that affect your performance, yeah, or factors in your performance. And then at the end, comes back to heat and acidosis and all right, yeah. So it’s kind of start here, but no, now we need to talk about this, and then let’s go back with the context.

Rob Pickels 28:23

Yeah, I will say, you know, my biggest caveat with this paper is, I think that this is very applicable to laboratory based endurance performance, meaning, if you’re measuring endurance performance in more of a steady state effort, a time trial, a time to exhaustion out on the road. Maybe that’s more of like your marathon in your 10k where you’re you’re leaving the starting line, you’re trying to run your best time and cross the finish line. I don’t know that this model explains all the variants when we say maybe talk about crit racing or road racing on the bike, or it’s a little bit more heads up, it’s a little bit more strategy, it’s a little bit more attacking and recovering. Then I think that this model is still probably explains a lot of endurance performance, but I do think that it leaves some things out.

Trevor Connor 29:15

I mean, he touches on but doesn’t really get into the neuromuscular side, correct? Yeah, a lot of those other things.

29:21

Another thing I always have to point this out. You can tell it was written in the 90s, because he talked about lactic acid. There is lactic acid, literally, it’s in one of the diagrams, yeah. Well, at the very least we know that there is an a hydrogen ion associated with the release of lactate from the cell. Yep. But

Trevor Connor 29:38

that figure two that you talked about. You know, this goes back to what we were saying at the beginning of this episode, that there’s some studies. You go back and go, Well, I already knew all that, but you have to remember at the time, this was groundbreaking, and that diagram every exercise physiology textbook has some version of. Of this diagram? Yep, but you have to understand that this is one of the key researchers who figured this diagram out, right?

Rob Pickels 30:07

And there have been other researchers that have taken this diagram in the subsequent years and expanded upon what it means. So you know, if we sort of describe this diagram a little bit. Close your eyes. Visualize this, for the people who are able to you know at the very top is performance velocity, meaning the speed that you’re holding for whatever the event is or the duration that you have to so

Trevor Connor 30:33

he defines performance as the speed at which you can do a certain amount of work. Okay, is that what it was in here? It was that or so? Yeah, let me. Let me read it, yeah. Performance can be evaluated by the amount of time required to complete a given amount of work. IE, power, there you go, or by the length of time that a given power output can be maintained, ie, capacity,

Rob Pickels 30:56

there you go. You know, playing into that performance velocity, he has resistance to movement, and that is a whole show on itself, right? That’s aerodynamics, rolling resistance. We’re cyclists, so we’ll think about it this way. You know, the resistance in your bearings, in your drivetrain, he doesn’t go into that. But the other thing that’s playing into this performance velocity is your performance power. Okay, great. That makes sense. As my power goes up, my speed will probably go up too. But playing into performance power is two things that are really important. The vo two, the amount of oxygen that you’re consuming and your economy of movement, how much work you’re getting out of that oxygen, those are the two biggest things that are playing into the workload that you’re able to sustain in your performance. Yep. So

Trevor Connor 31:46

continuing down that chart, so I’m actually going to take a step back and I will tell you I have reread an older paper of his before I realized I was reading the wrong paper. One to three that we picked okay, but there was a paper he wrote in 88 called determinants of endurance and well trained cyclists. And there’s several other researchers who did very similar studies. There’s another one by Michael Joy actually, here’s another one Michael Joyner and Edward Coyle. I was remember it was the Joyner paper, endurance exercise performance, the physiology of champions. Yep. So this is some of his that one’s actually 2000 neuter, yeah, newer, neuter, neuter, newer. We’re both having problems with Word today, but both of those studies talk about three key factors in performance, which is your VO two Max, your lactate threshold, and your efficiency slash economy. And saying those really are what separate a top endurance athlete from the rest of population, those kind of key three things. And if you look at this chart that you just described, the top of you go down. There’s a dotted line below what you just talked about, and then they talk about the functional abilities, and that’s where you have your maximum oxygen consumption, your lactate threshold, and your economy efficiency. So it’s those three key things, and that’s one of the things you’ve really seen with Dr Coyle, is he is hammered on those again and again and again in his research,

Rob Pickels 33:17

right? Yeah, I think that 1988 paper is awesome the determinants of endurance and well trained cyclists, but it doesn’t have the figure two chart.

Trevor Connor 33:25

No, it doesn’t. It doesn’t, because it’s way earlier. It’s 11 years later that he puts all this together. Yeah, and

Rob Pickels 33:32

that’s more of a research driven like, we’re gonna figure this out in cyclists. And this later one that we’re talking about is more of like, okay, what’s the model? How does this stuff fit together? And

Trevor Connor 33:42

part of the reason I just brought those three things up, and the importance of those, is because I’m giving a little teaser to the final Dr Coyle study, which we’re going to talk to he you’ve seen in his research, he’s been very interested in economy and efficiency. And in that third paper, when we get to it, it kind of bites him in the butt a little bit. Yeah,

Rob Pickels 34:05

so let’s talk about that economy and efficiency a little bit. So in this chart, he has the performance stuff on top in the middle category, it’s labeled functional abilities. And then at the very bottom is a row of morphological components. Right? This is factors within your body, your capillary density, your stroke volume, the thing that plays into the economy of movement the most is going to be your muscle fiber, type composition, right? And type one fiber composition explains, based on the numbers that he has here, 56% of the variance in economy, so that alone explains over half. And it’s disheartening for somebody like myself, who’s probably more type two dominant, sitting across the table from Trevor, who’s probably more type one dominant, and just say, God. God damn it, I will never be as economical as Trevor is. Yep. Sorry, but there’s, you know, you look at this, you look at this chart, it’s percent of type one muscle fibers and gross efficiency when cycling, our value of point seven, five, very, you know, positive relationship between the two. It’s pretty incredible how they found that alone. Okay, so what does that mean for us, if two people are riding at, say, the same oxygen consumption, two people going down the road at three liters of oxygen per minute, the one that’s more economical is getting more Watts from it, yep,

Trevor Connor 35:37

and by the way, nose, I haven’t cracked you at all about efficiency versus economy? Well, he

Rob Pickels 35:42

uses both in terms of mechanical efficiency and economy of movement, which would be watts per liter. I’m just

Trevor Connor 35:48

going to give another teaser. I said in a previous episode when you and I started arguing about the definition of efficiency and economy. Yeah, that we had done an episode on it. You had we hadn’t. Yeah, I’d written See, I had written an article, we never did an episode. So we’re can’t trust them. Can’t trust them. We’re doing that. Trust them. Rob and I are gonna debate it.

Rob Pickels 36:14

Well, my type two fibers are gonna outhead. Lock your type one fibers. And

Trevor Connor 36:17

I will say that when we have that debate. We’re going to be referencing Dr Coyle studies a lot because he was big on this. There you go. But you know, I love evolutionary biology. There is a rational reason, or a good reason for this. Our type one fibers are, you know what you’re doing when you’re doing more endurance type activity. You look back at our ancestors, they would run for a long time, but they didn’t run fast. They weren’t trying to win a marathon, so it was kind of walk running. So those fibers didn’t need to be strong, they just need to be efficient. So you could go for a long time. Type two fibers, particularly your two A’s, are your really strong fibers. That’s when you know, if you’re a hunter, you’re going in for the kill, or you’re trying to lift something really heavy, you just need to be powerful. When you’re using those fibers, you don’t need to be efficient. You’re not trying to do that for a long time, right?

Rob Pickels 37:11

And when you talk about efficiency, I think it’s important, and he mentions it in here, and I want to point it out to people. The gross mechanical efficiency that they saw in cyclists was between 18 and 22% and that is significantly less efficient. Most people assume 25% and assuming 25%

Trevor Connor 37:32

past episodes so much higher

Rob Pickels 37:35

than we actually see in people, we produce a lot of heat, right? That’s, that’s where all of the extra energy is going. For the most part, let’s be honest, right? We’re only getting 18 to 22% of the energy that we’re burning is actually powering our legs going to the bike, and I’m tying that. This is, you’ll see how all of this comes full circle. The other thing that we adapted, really, and evolved with, is our ability to manage heat much better than those things that we were chasing down over time. Right? My dog pants out his mouth. His long, two foot long tongue is dragging on the ground because he can’t sweat, can’t do anything else, but we have done a great job of heat, and that is something that, interestingly, is only somewhat touched upon in this paper. Yeah,

Trevor Connor 38:26

so some researchers have said humans are the purest endurance animals on the planet for a couple reasons. One is we actually don’t have the type two a fibers. We have 2x all of our muscle fibers are able to work at least somewhat aerobically, where a lot of animals have the two ways which can’t do any aerobic work. So all of our fibers can work aerobically. But another reason is our skin is porous. We are much better at dissipating heat than a lot of other animals. As you said, your dog, only way it can get rid of heat is by panting. Horses can sweat, but they’re still not great at dissipating heat. So while they can kick our butts in a 10 mile race, they hit a certain point where they overheat and they have to stop. So they’ve actually tested this put a good endurance runner up against a horse in 100 mile race, and a human can give a horse a run for its money in 100

Rob Pickels 39:21

mile race, but I don’t think the horse cares about money. Trevor, that’s fair. Horse doesn’t have a lot of money, so run much of a bet. Run for its oats. The horse is worth a lot of money. So I guess there’s that. No, you’re entirely correct. And on this heat side of things, you know, I just want to say, I think that they do point out that pre cooling, better performance. Preheating, worse performance. You don’t hear about preheating very often, but this is an area that I don’t think that athletes emphasize enough. And a quick story. You know my daughter, my daughter, runs track very hot day over the summer, she was running like USATF region. Animals here in Colorado, you know. So I went to the Kona ice the slushy truck, you know, was parked outside, got her a slushie. Was like, here you go, sweetheart. This is gonna help you run faster. And she was like, I don’t know dad. And she was like, embarrassed to eat it, you know. But this is, like, a number one thing, pre cooling with things like slushies, but athletes almost seem like they’re avoiding improving their performance in the heat. Another case is that oftentimes people will train when it’s cool out, like, Oh, I’m gonna go ride at six o’clock in the morning because it’s cool out, even though the race they have coming up is gonna send them heat exactly through the heat of the day. And so I think that people ought to be spending more time focusing on this thermal regulation, because it can really improve your performance. At the very least, it’s going to improve your plasma volume, which improves stroke volume, cardiac output, improves your lactate threshold, improves your VO two Max, even if it doesn’t make you feel more comfortable, which it does in the heat you get, actually, performance exercise benefit from it, just because of the adaptation to the heat itself. Yep. No, I agree. Sorry, that was a rant. Was that ranty? No, that

Trevor Connor 41:13

was good. Okay, good. The thing I actually want to go back to, because I just want to give you credit for this. When you said people think we’re 25% efficient, and that’s not the case. It sounds like we’re splitting hairs here, but here’s how important it is. If you’re 25% efficient, unless you have the worst vo two Max in the world, go race the Tour de France, because you you have a good chance of winning it. Yeah, the difference between 21% and 25% is, you know, decent razor versus Tour de France champion. Yeah,

Rob Pickels 41:44

Trevor, to put that into perspective, they had subjects with the same performance, VO two. And this is just looking at the high percent type one versus, like the normal percent type one. And it was 342 versus 315 watts, or the difference in the two of those, a 30 watt difference, just based on sort of the economy of people, is crazy.

Trevor Connor 42:09

Yep. So I think the last part that we want to talk about with the chart, we just, you know, we have his three key things, which he has hammered on again and again and again. VO two Max, lactate threshold, efficiency, slash economy. But then the bottom of the chart is the physiological, or what he calls morphological, components that determine whether you have a good vo two, Max, whether you have a good lactate threshold, whether you have good efficiency. And we touched on one muscle fiber, type composition, more type one, the more efficient you are. That’s the only one that connects to efficiency. His others are capillary density, which improves your ability to both deliver oxygen and clear lactate,

Rob Pickels 42:52

which was really interesting to me. That’s something I don’t think about all the time. I can keep going if you want, please, please. You got me intrigued? Yeah. Well, no, just with the clearance of the lactate, right? They talked about like the diffusion distance and being able to get that lactate out of the cell by having the capillaries closer. Whenever I just think about muscle capillary density, I always think about the delivery and not the removal. Yep,

Trevor Connor 43:15

no, it’s important for both. You know, the next one in the list, which also improves oxygen consumption. Is hemoglobin concentration, right? And if you want to know how important that is, when you hear about all these athletes doping with EPO, they’re just trying to increase their hemoglobin concentration. Sure are

Rob Pickels 43:32

or doping with carbon monoxide, yep, the newest. You know, because xenon gas was apparently too hard and expensive to get so they just went

Trevor Connor 43:41

carbon dioxide,

Rob Pickels 43:42

monoxide,

Trevor Connor 43:44

monoxide. Let’s poison ourselves. Oh

Rob Pickels 43:46

no, yeah. Well, just poison yourself a little bit. Okay, not a lot of it good

Trevor Connor 43:53

things people will do just kills me. Next one is stroke volume, again, proves oxygen delivery because you’re you’re pumping more blood per beat of the heart aerobic enzyme activity, so now you’re getting into the mitochondria, which is where aerobic metabolism happens. And basically, the more mitochondrial density you have, the more enzymatic activity you have, the better ability you have to take that oxygen out of the blood and use it to produce energy, correct? And then the last one is distribution of power output and technique. So that gets a little into that neuromuscular side.

Rob Pickels 44:31

Yeah, the distribution of power output one was interesting as well, because he talked about distributing the force that you’re creating over a larger muscle area, and in some regard, this was backward from how I always thought about it, in that more muscle, more oxygen, more oxygen for a given workload, potentially bad, right? That means you’re less economical. You’re using more oxygen to produce the same amount of power. However, I think that he’s discussing. Us in sort of the vein of, okay, we can increase the mitochondrial density of a fiber, but we can also increase the fibers with high mitochondrial density. And by doing that, that’s the increase of the distribution, not necessarily, say, calling upon type two fibers to do the work, having more type one fibers with great mitochondria to share the workload.

Trevor Connor 45:24

I think this is what we were both struggling with it, because normally when we think of an increase correct muscle fiber, so you talk about the cross sectional area of the muscle, yeah, if that’s larger, it’s generally because you have more type two muscle fiber, you’re just one of those big, bulky guys who’s really strong, those fibers aren’t as efficient. They can’t really use oxygen, so that actually hurts you, yeah? But you’re right, if you increase the number of slow twitch muscle fibers, right, the cross sectional area of that, you’re going to be stronger on the pedal stroke. Yeah? So yeah, I agree. I might get us in trouble, but I will put this chart in the show notes. It’s a great chart, and please just understand you’re going to look at this and go, Well, yeah, I’ve seen that my exercise physiology textbooks. But again, this was the the OG. He was one of the the people originally creating this whole concept. Yeah,

Rob Pickels 46:18

you know some last caveats on this one, he does call out, hey, this stuff only occurs this way. In this model, if the athlete is well fed, they’re well hydrated, they’re motivated, and they’re not hyperthermic, and that any of those four things and maybe more, could really undermine this model, right? You run out of carbohydrate. The rest of this probably, you know, goes cattywampus a little bit fast.

Trevor Connor 46:45

Good point. Yeah, no, he does talk about the the areas of fatigue. So I think we need to leave some time for the big study,

Rob Pickels 46:53

the big study that I think this is the elephant in the room. Yes,

Trevor Connor 46:59

it is. Now. I’m going to start by saying it might not be the case anymore, but certainly, when I was doing my master’s, this was like, if you were an exercise physiology student, you’ve read this study probably multiple times in different classes. Yeah, it was just the study everybody talked about. And so there is a lot of backstory behind this. So maybe we start, we’ll talk about the study, but then we’re going to give you the whole story outside of the study. Do

Rob Pickels 47:30

we want to start with the title, or do we want to skip the title? Go right

Trevor Connor 47:34

ahead? Well, what I found really funny about the story is he’s trying to be a proper researcher and not say who He’s researching, but your two sentences ended like, frankly, in the title, you can figure out who he’s talking about. Did you? Did you

Rob Pickels 47:51

look at the references and look at what the first reference was? I was like, wow, that’s a dead giveaway, right?

Trevor Connor 48:00

So a lot of a lot of researchers will study famous endurance athletes or famous athletes, but I guess propriety dictates that you try to keep it anonymous. This one, not so much.

Rob Pickels 48:16

Yeah, Trevor, I think that there’s some researchers who have almost kind of made a career or a foundation of their career, like Dr Lucia, who have studied elite athletes, but oftentimes, I think that it’s a group of elite athletes, and this particular paper that we’re talking about, it’s a case study of one particularly elite Tour de France, multiple time champion. Yep, I’ll

Trevor Connor 48:39

give you another quick example before we dive into this, there was a great study by Dr Pino called a six year monitoring case study in a top 10 cycling Grand Tour finisher. And when I read it, I went, Oh, absolutely, that’s Quintana.

Rob Pickels 48:53

Interesting. I was wrong, really. I was wrong. Who was it? Was really? Was it getting Thibaut Pinot? No,

Trevor Connor 49:03

that would be interesting. No, it wasn’t, but it was. It was a French rider. I’m blanking on the name, but like I’m looking at my notes on it, and I just used quintana’s name, and then later found out, no, I had that wrong. So some researchers actually do this. They’ll do the case study of a top athlete and hide it well enough that you don’t know who they’re talking about. Sure, sure. Yeah. Okay, not this one.

Rob Pickels 49:25

Let’s talk about this athlete, Trevor. Yes, he got better over the years.

Trevor Connor 49:29

Yep, he was, at the time of the the writing of this study, a five time champion or six time champion of the Tour de France.

Rob Pickels 49:37

At the time of the writing of this study, yes, may or may not hold true today does not hold true today. Maybe he won more since this study came out. Maybe had them all

Trevor Connor 49:47

taken away from him. If you haven’t figured out who we’re talking about,

Rob Pickels 49:52

the first reference is a book titled it’s not about the bike by

49:56

Lance Armstrong. I. Yeah, so not well hidden, but yeah. I mean, it was fascinating that he, let’s give credit where credit is due. And I don’t think this was given by people that attacked the study. He started this research when Lance Armstrong was still basically U 23

Rob Pickels 50:15

Yeah. He was like, 18 or something. Yeah. Was it that young? Pretty young,

Trevor Connor 50:19

and just 2121 just appearing on the scene. He they had no idea when they started the study that he was going to be a multiple champion of the Tour de France, right? That’s important to point out. This was just a strong American cyclist. Remember, Dr Coyle is down in Texas. Armstrong was from Texas. There’s a certain rationale behind let’s, let’s study this guy. He’s young. He has a lot of potential. Let’s see if we can see what happens over his career, right? It was just kind of that, Oh, my God. We just now got all the data for a multiple time Tour de France champion. Yep, yep. So I’m not sure we need to go into the minutiae. I think really, we just need to cover the overall results, which was, you know, they they did test some so they did a lactate test, they did a vo two max test. They they measured gross mechanical efficiency and delta efficiency, yep, which we’ll talk about in a second. And they did this when he was 21 so let me look at the ages here, 21.1 and it looks like 21.4 so relatively close to one another when he was 22 then there was a big gap because he had cancer, yep, then when he was 25.9 and I don’t know why I’m giving the decimals when he was, when he was 28 I’m just, I’m just reading off here, very precise with these notice. So 28 that was november of 1999 that was the only one that was done after he had won any of the Tour de France. And

Rob Pickels 51:56

it was preseason, right? And they do call out training stage when he was 21 preseason, another preseason when he was 21 a racing season when he was 22 like you said, the reduced training at at age 26 because that was after the chemo and the cancer treatment. And then again, preseason at 28

Trevor Connor 52:16

none of these were done in season. None of these were done right around when he was on peak form, that’s correct.

Rob Pickels 52:23

The racing one when he was 22 was in September, so that would have been the very tail end of any racing that was happening. So

Trevor Connor 52:32

he ended up with all this great data on suddenly, one of the greatest tour riders of all time at the time. And you know, obviously you want to dive into this and go, okay, in 1992 this guy was not capable of winning the Tour de France. This guy wasn’t capable of a top 10, yeah, now he’s a champion. Let’s try to see what the difference is. And look, I’ll state here the obvious. We now all know that he doped. Yeah, we all know that was a factor at the time, and we’re actually going to get into this, he was fighting pretty hard against any claims that he was he was doping and saying he was doing this clean. Yeah, he had not admitted to it yet. So what they found in the study, there’s a lot of things, there’s a great chart in here that shows all the the different metrics, but the the key findings were, VO two Max did not change. It

Rob Pickels 53:23

did not change. Overall, it did fluctuate a little bit up or down preseason to race season, yep.

Trevor Connor 53:29

But overall, you didn’t see a giant jump in vo two Max,

Rob Pickels 53:34

yeah. To put that into perspective, right, January, 93 a preseason. VO two max test, 5.8 liters a pre season in 1999 six years later, 5.7 liters.

Trevor Connor 53:46

Now here’s another thing that actually really makes you scratch your head his lactate threshold as a percent of his vo two Max went down correct and you look at any studies looking at top cyclists, top endurance athletes, and one of the biggest adaptations you see is their lactate threshold gets closer and closer to their vo two Max. It becomes a higher percentage, not a lower he went from 85% down to 76% and

Rob Pickels 54:17

was very stable at those right and he dropped from 85% in November of 92 to 78% in January of 93 and then he stayed 7876 76 for the remaining measurements, I have that highlighted on mine because I found that really fascinating as well as

Trevor Connor 54:38

confusing. And note they didn’t measure that in 1999 so we don’t know what percentage it was when he was winning the Tour de France, yep,

Rob Pickels 54:48

yep, yep. So if we look at that as a percent, it drops, right? If we look at that in terms of lactate threshold, o2 uptake in liters per minute, it drops even more. There, but because his vo two Max isn’t necessarily going up either. That’s why the percents like his vo two Max is coming down, but the percents are staying the same because of that, yep. So

Trevor Connor 55:12

what they found was there were only two things that consistently changed in Lance Armstrong. One was an increase in both his gross and delta efficiency, very similar increases. So I’ll just give the gross went from 21.18% up to 23.05% not 25 not 2523 is extremely high. Yep. Yeah. And a what was it? An 8% drop in body weight,

Rob Pickels 55:44

something like that. Yeah, his body weight, body kilogram, was 79 essentially, for that first measurement, actually race season, he was down to 75 he was back. He looks like he’s about 79% when he’s not in race season, but he does lose like four kilo from pre to race season, yeah.

Trevor Connor 56:05

And what this amounted to was a net 18% improvement in the power that he could put out at a given oxygen consumption per kilogram,

Rob Pickels 56:20

right? And so, you know, we just talked about how this mechanical efficiency is what they’re dubbing it in here. But when we look at power per liter, then we’re talking about economy at five liters of oxygen, which is quite a bit of oxygen. Most people don’t have a vo two Max, exactly at five liters of oxygen. Initially in 1992 the very first measurement, he was putting out 374 watts at that point, that was 21% efficiency, a 2% increase in efficiency from 21 to 23 the very last measurement, 28 years old, 23% efficient. We go from 374 watts to 404 watts, 30 watt improvement for a 2% gain in efficiency, right? That’s incredible,

Trevor Connor 57:08

yeah. And so the explanation here is that’s what took him from an impressive cyclist to the dominant person that people remember, right?

Rob Pickels 57:18

This is interesting to me for another reason. We assume these results are tainted because of the doping. However, the second to last measurement was at 26 years old. It was when he was just starting to ride a bike again, and it’s as described, believe this, if you want or not. As described, it basically says, like Lance hadn’t ridden in months prior after his treatment, but he did ride for about a week prior to coming into this measurement, right? And I think that that’s based sort of on Lance’s recollection in his book, or whatever else one would assume, in that case, he was not on any sort of doping products, right? That measurement after that was still 22.6% efficiency. It wasn’t as good as his best, but it was much better than his earlier years. He was still doing 399 watts at five liters. So I wonder, I have to just ask, is the increase in muscular efficiency, which is literally the title of this paper, is that still valid, even though they’re the doping sort of confounding factor here?

Trevor Connor 58:38

Well, that is the key question. And I think you’re shifting us to the broader conversation about this study. And yeah, I’m going to start by saying I agree. We now know that Armstrong was doping. Doping will enhance vo two Max, it enhances oxygen delivery. It does not help efficiency. So you know, there is an argument that the weird things we’re seeing in the lactate threshold and the not just seeing no change in his vo two Max, because, like you said, they don’t generally dope in the off season, you’re constantly being tested. You’re only going to take the risk when you really need to take the risks, and you don’t need to be taking the risk in November. Yeah. So that’s going to skew some of the results, and that’s why it would have been great to get some results from him in June or July, because I think you would have seen very different vo two Max and lactate threshold numbers.

Rob Pickels 59:26

Yeah, no, certainly, right. And his vo two max at that time, where he was presumably off everything, 5.3 liters, the one measurement they have three years prior, at the end of the race season, was 6.1 and we can probably assume at its peak it was higher than 6.1 maybe a little artificially inflated with that increased hemoglobin, like we talked about in the previous paper. Yep. But

Trevor Connor 59:51

now let’s get into the dark side of this paper, because he published it, and then it got, you know, it got challenged, and. Yeah, because it’s generally assumed, and we can talk about this too, but certainly at the time, the very strong belief in the science community is efficiency cannot be improved. We just talked about this in the previous paper. Really efficiency is about the percentage of type one muscle fibers, and he talks about this in the Armstrong paper. And the belief at the time was fibers don’t convert. You have what you have. You have the percentage of type one fibers you’ve got, and it’s never going to change. And Coyle’s explanation in this Armstrong paper was that Armstrong saw a substantial switching of fibers from type two to type one, his percentage of type one fibers went up substantially. And they can’t prove this, because the only way to do that would be with muscle biopsies. And Armstrong wasn’t willing to do biopsies correct, yep. So it’s, it’s a guess, and that was the conclusion of his paper. So it got challenged when it came out. A lot of scientists had issues with this. But then it got a little darker, because at the time, I forget the Do you remember the name of the insurance company? There was an insurance company that was suing Armstrong. So Armstrong, or I guess US postal, was using this insurance company, and there was an agreement that if Armstrong won his fifth tour, they would pay him $4 million Sure, and they didn’t want to pay the $4 million so they sued on the basis that they believed that what Armstrong did was not possible, yeah, and that he was doped, and that negated the contract, so they didn’t need to pay him, and they took him to court, Armstrong, and this is so that was in 1999 that this, course, case was happening. This paper was published in 1999 and Dr Coyle was paid by Armstrong’s legal team. I didn’t know any of this, to come and testify what? And this paper was the center of it. And he said that Armstrong couldn’t have been doping, because doping doesn’t affect efficiency, and what doping does affect, which is your VO, two, Max, your oxygen, deliver, your lactate threshold. We didn’t see improvements in that.

Rob Pickels 1:02:23

Hmm, I never knew any of that. Trevor

Trevor Connor 1:02:27

gets a little muddy, doesn’t it? Well,

Rob Pickels 1:02:30

it certainly does. So

Trevor Connor 1:02:32

that set a lot of researchers really off, and they then started to say, they claim, basically, you know, it’s one thing to make mistakes in research, it’s another thing to have unethical practice in research. And a group of researchers basically called unethical practice in this and said they they sued the university to get the raw data to see if there were any issues in how this was analyzed. And to this day, Coyle only released the results from the first test in what was it, 1992 Yeah, sounds about right. He only released that first test, and so a lot of researchers are very upset about that, saying, if you’re not trying to hide something, why wouldn’t you release all of the data? Sure they then did go into that data from the first test and discovered a flaw in the research. You’re

Rob Pickels 1:03:42

gonna let me know this stuff ahead of time so I can be prepared. Sorry, I

Trevor Connor 1:03:45

only read all this last night. What? No

Rob Pickels 1:03:49

more. Midnight text from you, Trevor, it’s like you don’t even love me anymore. Sorry about that, Rob. So Rob here, elucidate. Trevor, I need to.

Trevor Connor 1:03:56

I need more. I can elucidate. I’m gonna throw this back to you, because this, I know you understand better than me, explain the difference between gross efficiency and delta efficiency? Yeah, it’s

Rob Pickels 1:04:07

a great question. Gross efficiency, we’re basically looking at what energy does it take to produce a certain amount of energy, right? And this is why it’s an efficiency, and it’s why it’s a percent. Basically this much energy nets you this much energy.

Trevor Connor 1:04:20

So it’s energy used to energy out exactly, exactly.

Rob Pickels 1:04:24

Now, one of the major contributions to that is just the energy that it takes to, say, move your body through the range of motion. Right? Why that’s important is this, if you sit on a bike and it doesn’t have a chain on it, and you just start pedaling against no resistance at all. Guess what? Your oxygen cost goes up right the amount of energy exactly you’re expending energy. So the movement itself takes energy that has a larger contribution to low level at. Hertz right as a percent of how much it takes to pedal 25 watts, that’s a pretty big percent as a percent of how much it takes to pedal 250 watts, it’s relatively less Delta efficiency looks to remove that energy it just takes to do the movement out of the equation. So that we’re looking more purely at how much energy does it take to actually apply power in the movement that you’re doing, and that very simply, is the slope of the line when you graph out more than one point across a graph. So we can make a graph of like gross economy, but we can also make a graph of the Delta efficiency, and that removes that little bit of movement economy. I’ll say that gets put in there for all intents and purposes. I think that we can just rely on the gross efficiency, and that’s going to get us 99% of the way there.

Trevor Connor 1:05:58

That is interesting, because here’s the thing. So I just want to emphasize this is really important. So gross efficiency is factoring in all energy that your body’s using. So even when you’re sitting on the couch, yes, you are burning energy. Yes, that’s factored into the gross efficiency. So you’re measuring how much energy your body is burning, your muscles, all your cells are burning, and then you’re comparing that to how much is going into the bike, and saying, that’s your gross efficiency, right? But not all that energy is being used for the bike. So delta efficiency looks at changes as you increase intensity. So that allows you to eliminate energy that you would just be using anyway, if you were standing still, as you said, if you’re just peddling the bike with no chain correct, it eliminates that. So now you’re looking at what is going into the bike, and when they looked at the Delta efficiency, how he calculated it, what they discovered is so delta efficiency uses that line. As you increase work rate, you see oxygen and consumption going up, and you’re looking at the slope of that line. But if you take that line down to where work rate is zero, oxygen use is not going to be zero, because you’re not dead. You’re still breathing, the way he calculated it, the line goes to zero, correct? But that’s Delta efficiency. No. But Delta efficiency shouldn’t go to zero. It should no when you get work rate goes to zero, you are still consuming oxygen Correct. You’re still going to have some oxygen consumption. What Coyle did, the way he calculated, is when work rate goes to zero, oxygen consumption goes to zero. That’s how he did the slope of the line. And when you correct for that, taking just those first results, and you have the correct Delta efficiency line where it doesn’t go, where you don’t have zero oxygen consumption at zero work rate, and recalculate his efficiency in 1999 or when he was 21 it was still 23% it eliminates the improvement, the improvement into delta efficiency. Coyle has argued against this and said, Yes, I made that mistake in the calculation, but it’s a minor factor, and it doesn’t impact anything well,

Rob Pickels 1:08:14

you know, I think that it still leaves the improvement in his gross efficiency as well, which is a very simple calculation, and we do see, you know, changes over the years in that gross efficiency. Yep.

Trevor Connor 1:08:29

So here’s where we’re at with this. Dr Coyle has still refused to release all of the data when he’s been asked about it, since he’s gotten quite angry, and basically his statement is, don’t these people have jobs? Don’t they have better things to do? He’s admitted that he made the mistake in the calculation, but has said it wasn’t that important. It doesn’t make that big a factor. And said ultimately, what he was trying to do was take some very interesting data and try to explain something. He was not being paid to fabricate anything, and he still believes, yeah, there was an improvement in efficiency. I am going to point out since then, there has been a little more openness in the science that, yeah, there is improvement in efficiency. So I’m actually looking at a 2019 study seasonal changes in gross efficiency and aerobic capacity and well trained road cyclists. There have been studies since that say actually we are seeing fiber conversion, right? That you can see an increase in type one muscle fibers, yeah, so I think we’re more open to that. So I’m not sure this is a nefarious case, even though he was paid by Armstrong’s team of somebody trying to fabricate something to hide doping, I do personally feel open to the possibility that this was just a researcher with some very interesting data who might have made a few mistakes, but you look at his previous research and all the work he’s done on efficiency, which. Really believe that efficiency could improve, and since then, there’s been some signs to show, yeah, actually, fiber type can change,

Rob Pickels 1:10:07

right? And maybe there is an easier conversion between a two a and a 2x fiber. And I think that conversion between a type two and a type one fiber might be a little bit harder, but I think that we’re generally accepting it does happen. Now, you know, we do have to ask, you know, like I said, are these results still valid in light of the doping throughout the year? That’s the second question, you know. And I think that Dr Coyle, at the time, you know, a researcher that maybe had incomplete information and is just trying to connect the dots maybe, but maybe there was an extra.in there that needed to be connected, but it was invisible ink, so he couldn’t connect that one. You do have to wonder, because of the performance enhancing drugs, was the training better? Was he able to handle more volume at higher workloads? Did that increase the conversion to type one fibers? Did that help push this fiber type change, you know, a little bit faster, to a greater degree over the years. You know, I think that we may never know. You know, people do say the effects of doping last much longer than just sort of, maybe the transient increases. You know, once your hemoglobin goes back down, your VO two Max goes back down. It’s not as if all is forgotten in some regard, right? You can still be performance improved after that, even though you’re off the drugs at that point in time. And maybe a way that you’re better is through something like this, maybe it does push the efficiency a little bit better, because we’re able to get a little bit more fiber type conversion.

Trevor Connor 1:11:34

So I’m really glad you brought that up, because, like I said, there have been studies since that have shown improvements in efficiency. And some of those studies, including the one that I just mentioned, as I remember, bring up the fact that when you see athletes do hypoxia, go up to altitude, or train in a hypoxic chamber, or breathe carbon monoxide, yeah, that can actually improve efficiency a little bit Sure, and remember, Armstrong was on EPO. Basically, when you put yourself in a hypoxic state, that increases your natural EPO. So you’re doing the same thing as what hypoxia would do to you correct. You’re just you’re doping at a level higher than what your body would normally produce, but it would produce the same effects. So there actually is now research showing that doping could potentially, you know, there hasn’t been the direct study of Yes. Here we gave this person EPO their efficiency improved, yeah, but we know that hypoxia can affect efficiency, so there is evidence that the doping could have improved as efficiency a little bit,

Rob Pickels 1:12:38

right? And so we brought it up a couple times. We’re talking about hypoxia now. So I just want to bring this full circle. You know, athletes have been purported. There’s been rumors that people are using now carbon monoxide. Previously, it used to be xenon gas. The way that these things work is, instead of going to altitude, instead of injecting EPO, you can trick your body into thinking, actually, I guess you’re making your body hypoxic by breathing in either Xenon or carbon monoxide. And this kills you, right? Because the carbon monoxide binds to hemoglobin, and it sticks to the hemoglobin, it doesn’t fall off the hemoglobin, and that means oxygen can’t get to the hemoglobin, which means you can’t get oxygen to your tissue, which means you’re hypoxic, which means you do this too much and you die, right? So do not, if you are listening to my words, do not try to do this to improve your performance. The reason that people were using xenon gas is it has a little bit less affinity than carbon monoxide does. Carbon monoxide holds on pretty tight. Xenon holds on kind of tight, but it falls off sooner, which means you’re less likely to go fully hypoxic here. But this is a way that people are because it’s undetectable. You can’t find EPO in your body when you’re breathing in these gasses. This is a way that people are trying to dope and increase their hemoglobin mass now, but it seems, it seems pretty dangerous.

Trevor Connor 1:14:08

Yep, no, agreed. So I’m glad you said that. Please don’t do it.

Rob Pickels 1:14:12

Yeah, don’t. Don’t. It’s, it’s totally not worth it, yeah?

Trevor Connor 1:14:15

So where I’m at with this Lance Armstrong study, and I’m interested in where you’re at. Dr Coyle has done a ton of great work in the exercise physiology world. There is a lot that we now just, you know, it’s fundamental when you study exercise physiology that he discovered, and I think he has been a fantastic researcher through the years. So I hate seeing a study like this taint. I personally want to believe there was nothing nefarious here. I think he would just kind of locked onto the rider that he got. He got incomplete data in light of the fact that we now know Armstrong was doping. I think that kind of invalidates all the data. So I don’t think. It was a nefarious attempt to help Armstrong hide his doping. I think you just have to look back on and say it’s just not a great study, and you can’t draw any conclusions from it with what we know now, yeah, and I don’t

Rob Pickels 1:15:11

even think it’s you can’t draw conclusions because of anything. In regard to Dr Coyle, it’s that we don’t know enough to know how the doping affects the things that he measured. This paper could be 100% valid, or it could not be. We literally have no clue, which means that I don’t know that we can trust this and cite this or whatever for future work. But again, I think that Dr Coyle was doing the absolute best that he could at the time with the information that he had, and, you know, recorded some interesting information, was trying to get it out to the general public. And we just, we have another page in that book now that helps us see the bigger picture.

Trevor Connor 1:15:51

I have seen enough research to say there does appear to be some fiber type conversion. It takes a long time that you can improve efficiency. If people ask me for my evidence, I’m just not going to use this study, one of the pieces of evidence. There’s enough other good studies now.

Rob Pickels 1:16:08

I think that that’s probably worthwhile. Trevor, maybe we should do an episode on fiber type, on plasticity of fibers. I think we’ve talked about it a little bit when we did in a whole episode. We haven’t, but we did kind of like one of our physiology, one, oh, ones. I think we discussed it a little bit. It could be a mechanism. Could be an interesting thing.

Trevor Connor 1:16:27

I think that would be a really interesting study, because even Dr Coyle mentioned this at the time, that there had never been longitudinal studies done. They had done comparisons of elite endurance athletes to amateur showing, yes, those elite endurance athletes had higher percentages of type one. But the question was always, were they born with it, or did they develop it? And at the time that this, this study came out, they didn’t have an answer, yeah. It

Rob Pickels 1:16:54

looks like they did a cross sectional observational study in 91 Yeah. Okay, interesting. All right.

Trevor Connor 1:17:00

Do we leave it there any last thoughts?

Rob Pickels 1:17:03

No man, let’s close the chapter in this book. Move the heck on.

Trevor Connor 1:17:07

All right. Good conversation. Rob, thanks. Trevor, thank you. That was another episode of fast talk. The thoughts and opinions expressed in fast talk are those of the individual. Subscribe to fast talk wherever you prefer to find your favorite podcast, be sure to leave us a rating and a review. As always, we love your feedback. Tweet us at at fast talk labs, join the conversation at forums dot fast talklabs.com or learn from our experts@fasttalklabs.com Rob pickles and Dr Edward Coyle. I’m Trevor Connor. Thanks for listening. You.

Nerd Lab: Dr. Edward Coyle’s Defining and Controversial Work on Endurance Athletes

Dr. Edward Coyle was a pioneer in figuring out how endurance athletes adapt and defining what attributes—such as efficiency and fuel utilization—are most important to perform at the highest levels.

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