Nerd Lab: Dr. Véronique Billat – A Pioneer in Interval Training Research

In the early days of interval training research, it was hard not to come across the name of Dr. Véronique Billat who shaped much of our current understanding of interval training.

FT Podcast 297 Nerd Lab

Interval training is as fundamental to endurance sport training as putting on a pair of running shoes or clipping into a set of clipless pedals. Yet, many of us were born before the term “interval training” was even coined. It was only in the 1960s that Per-Olof Astrand started studying interval training extensively in the lab.  

Back in the 1990s and 2000s, French researcher Véronique Billat was one of the pioneers of interval research, and today, she’s still publishing and hosting YouTube channel. At a time when the field was completely dominated by men and research about male athletes, Dr. Billat, more than almost any other researcher, defined what interval training was and how we research it.  

Many concepts that we consider cutting-edge ideas like the importance of spending time at VO2max and the power of short intervals (like 30-30s) are concepts she helped pioneer or out-right invented. In the case of 30-30s, it is a workout that many top coaches today still consider one of their top routines.  

In this episode, our hosts Rob Pickels and Trevor Connor review a few key studies from Dr. Billat’s illustrious career, starting with her most cited review, Interval Training for Performance: A Scientific and Empirical Practice. In this 2001 review, Dr. Billat traced the history of interval work and then raised the question of whether long or short intervals were better for aerobic training. While a long-accepted notion now, in this review, Dr. Billat raised the question of the importance of spending time at VO2max but ultimately drew a surprising conclusion.  

Our hosts then jump to a 1997 study where Dr. Billat tested the impact of individualizing the length of intervals for each athlete – based on the length of time they could run at the velocity associated with their VO2max. Individualizing interval work to each athlete is considered a very recent concept, but Dr. Billat was testing it, with a lot of success, in the mid-1990s.  

Finally, our hosts discuss a 1996 review called Use of Blood Lactate Measurements for Prediction of Exercise Performance and for Control of Training. While the first review exploring VO2max set standards that are still in place over 20 years later, this review showed how early the research was on blood lactate physiology in the 1990s. It was a time when VO2max – and not FTP – reigned supreme.  

If you’ve wondered where many of our current beliefs about interval work came from, then this is not one to miss. 

So, get ready for some intensity, and let’s make you fast! 

RELATED: Episode 251: Time at VO2max: An Important Metric You Probably Haven’t Heard Of 

RELATED: Episode 227: How to Make VO2max Workouts and Threshold Workouts Work for You, with Hunter Allen 

RELATED: Episode 168: How Much High-Intensity Training Do You Need? 


​Billat, L. V. (1996). Use of Blood Lactate Measurements for Prediction of Exercise Performance and for Control of Training. Sports Medicine, 22(3), 157–175. Retrieved from 

​Billat, L. V. (2001). Interval Training for Performance: A Scientific and Empirical Practice. Sports Medicine, 31(1), 13–31. Retrieved from 

​Billat, L. V., & Koralsztein, J. P. (1996). Significance of the Velocity at V̇O2max and Time to Exhaustion at this Velocity. Sports Medicine, 22(2), 90–108. Retrieved from 

​Billat, L. V., Koralsztein, J. P., & Morton, R. H. (1999). Time in Human Endurance Models. Sports Medicine, 27(6), 359–379. Retrieved from 

​Billat, V L, Flechet, B., Petit, B., Muriaux, G., & Koralsztein, J. P. (1999). Interval training at VO2max: effects on aerobic performance and overtraining markers. Medicine and Science in Sports and Exercise, 31(1), 156–63. Retrieved from 

​Billat, V., Palacin, F., Poinsard, L., Edwards, J., & Maron, M. (2022). Heart Rate Does Not Reflect the %VO2max in Recreational Runners during the Marathon. International Journal of Environmental Research and Public Health, 19(19), 12451. Retrieved from 

​Billat, V., Petot, H., Karp, J. R., Sarre, G., Morton, R. H., & Mille-Hamard, L. (2013). The sustainability of VO2max: effect of decreasing the workload. European Journal of Applied Physiology, 113(2), 385–394. Retrieved from 

​Billat, Veronique L., Richard, R., Binsse, V. M., Koralsztein, J. P., & Haouzi, P. (1998). The V˙o 2 slow component for severe exercise depends on type of exercise and is not correlated with time to fatigue. Journal of Applied Physiology, 85(6), 2118–2124. Retrieved from 

​Billat, Véronique L., Sirvent, P., Py, G., Koralsztein, J.-P., & Mercier, J. (2003). The Concept of Maximal Lactate Steady State. Sports Medicine, 33(6), 407–426. Retrieved from 

​Billat, Véronique Louise, Palacin, F., Correa, M., & Pycke, J.-R. (2020). Pacing Strategy Affects the Sub-Elite Marathoner’s Cardiac Drift and Performance. Frontiers in Psychology, 10, 3026. Retrieved from 

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Episode Transcript

Trevor Connor  00:04

Well welcome everybody to another episode. It’s just Rob and I sitting here we’re doing another seminal episode and I picked the author. I thought this would be a really interesting one to look at, and I’m going to start with an apology that I’m the Canadian. I spent 13 years studying French. I’m probably going to mispronounce her name, but Rob’s gonna get it right. So it’s Véronique Billat.

Rob Pickels  00:27

Billat, I think the most important part.

Trevor Connor  00:30

There you go. Now we got it.

Rob Pickels  00:31

But she is French, and what I think is really interesting is she is one of really the few female physiologists throughout history. I think it’s important to call that out that in an otherwise male dominated profession, I will say in terms of research professor in a field that oftentimes tests male subjects, I think it’s really important that we highlight some of the female contribution that’s out there, because regardless, she did absolutely amazing work that is formative in the future. And

Trevor Connor  01:04

I think to take it a step further. Well, she is still doing research now. And we are picking her studies, I looked at a 2023 studies you pointed out she has a YouTube channel, though it’s in French, it

Rob Pickels  01:14

is in French, I tried to watch it. I didn’t didn’t make it very far. But she

Trevor Connor  01:18

was doing research back in the early 90s. And I think what’s really important to point out about her is not only how vast or body of research is, but how much she has really defined how we have looked at interval work. Yep.

Rob Pickels  01:36

And I think that what’s especially important about what she has done is she’s what I’ll call a coach’s physiologist, right, were reading her research. And we’re going to cover three studies, one from 96, one from 99, one from 2001. Reading her studies, there’s a lot of understandable practical information. It’s not theoretical, it’s not acronyms, it’s not biochemistry, and all of that it is there’s a lot of great take home messages that coaches can directly apply to the work that they’re doing with their athletes. Yep.

Trevor Connor  02:09

And even see her pointing some of this out in her studies and reviews. So the 2001 review, which we’ll get to in a minute, right at the very beginning of that she made two interesting points that really caught my attention. So she pointed out the fact that in the lab, remember this is 90s and 2000s. Most of the research was in running and so a big number was your velocity at VO two max. So when they did a test and you undetermined vo two Max, what was the velocity you were running at? So that was that key number but think of it is very similar to if you’re a cyclist powered view to exactly. And all the studies would calibrate based on either running at that velocity of vO two max or running out a percentage of it. But she pointed out, coaches tend to calibrate based on what speed you’re going to be running in a race. And she then made a statement that just kind of I went well, which was there hasn’t been a whole lot of big breakthroughs in the lab. Most of the big breakthroughs in training have been out in practice with coaches. Well,

Rob Pickels  03:12

Trevor, I do want to say because you bring up the lab, I want to kick this off with a funny story before we dive in too deeply. Earlier in her career, she worked I believe in Paris and then kind of through two of these studies. She was at the University of Lille in France. And funny story is this I was in Antwerp, Belgium for work one year, and I love cyclocross. And so there was the quantum cross legal race. And in my mind, because I was familiar with her and her work and her university. I assumed the race was in France. And so the day before the race I left after I finished up work, I drove from Antwerp, Belgium, about what two hours I think to Lille two and a half hours to Lille, and got there had dinner, woke up the next morning and said I should figure out where the course is, before I go to it. The course was actually in Lille, Belgium, which was another two and a half hours way I was in the total wrong country at this point. So I had to get back in my car, rush back to Belgium drive past Antwerp or I had started from the day before. And fortunately, I made it on time and life was grand. But you know, I got to see two wheels in a day. So there you go. I love

Trevor Connor  04:23

Europe where you can be like in France, and go oh crap, I need to be in Belgium.

Rob Pickels  04:31

And maybe you could still get there you are. Exactly. Exactly.

Trevor Connor  04:34

I come from Canada like to cross provinces. That’s a major trip. Well,

Rob Pickels  04:39

it but it’s only on one road. Yes. Literally with cars with square tires. So

Trevor Connor  04:44

little Canadian flag for I used to live just off Yonge Street, which is the longest Street in the world and something like 5000 kilometers. It’s

Rob Pickels  04:53

perfect. I love it. If you’re an endurance athlete, the status of your GI systems reaches further than just your overall health. It directly impacts athletic performance tuned into fast Oxfam’s episode 123 To listen, as Dr. Allen Lim sheds light on groundbreaking gi information that every coach and athlete can benefit from to leverage and optimize their nutrition plan. Check it out at fast talk which one we started with today, Trevor,

Trevor Connor  05:24

I actually even though this is the last one, so two of these from the 90s. As you point out once from 2001, I would like to start with the 2001 review for two reasons. One is when you look at all of her research, and how often they’ve been cited, this is far and away her most cited study or review. The other reason I want to start with it is because she starts with a whole history of interval training. So it’s an interesting review that she first half is all this history, you know, how we got to where we’re at. And then the second half is saying, Here’s what we know so far about interval training. And bit of a spoiler alert, what I found really interesting there as the whole time, she’s talking about what we’ve seen with interval studies, she’s kind of heading in one direction. And then when she gets to the, here’s the long term adaptations that we see the kind of contradict where you think she’s going, which I found interesting. So we’ll get to that. But the name of this review is interval training for performance, a scientific and empirical practice. And then in the second part of the title is special recommendations for middle and long distance running. Part One aerobic interval training, this

Rob Pickels  06:37

is the easiest to read French I’ve ever seen. Yes.

Trevor Connor  06:42

Well, we just pointed this out before we on live that they were great reviews, sometimes it can be a little hard to read because she wrote them solo English as their second language. And there were times where you just read a paragraph, and what did you say it seemed really important, it seems really

Rob Pickels  06:57

important, but I couldn’t quite grasp what was being said. And there were certainly a few paragraphs where I had to re read and take my own notes as I was going through to piece things together. But I will say her English is absolutely incredible. It’s just that with some of the nuances when you’re discussing some of the finer points, I 100%, understood what she meant. It just wasn’t intuitive for me, full of amazing information. Agreed.

Trevor Connor  07:25

So do we want to start with the first part of this the history? Well, it’s

Rob Pickels  07:31

up to you, I, when I was reviewing this gift, the whole history part and just went straight to the empirical part. I

Trevor Connor  07:40

love the history part. So let me just quickly cover it what I found really fascinating. First off, she starts with the fact that the first time interval training was really described in the literature. And when it really became popularized was in the 50s. I found that really interesting, because you think this is something Oh, we’ve been doing for a long time. I read that Oh, my God, my parents were alive before anybody really heard the term interval work, right? It’s not that long ago that we really started thinking about this. Now she did point out that before that they had kind of naturally discovered like, they would use hills. You go hard up the hill, and then recover coming down, things like that. But it really isn’t that long ago that we’ve really started to describe interval training. Yeah.

Rob Pickels  08:27

And she points out in here EMALS, adipec, 1952 gold medalist she describes as the most famous athlete to use interval training, right, and kind of the initial way that it was being instituted. For me what was really interesting, as I glanced over the history section, there were so many names. Trevor, if you think back to craft of coaching, which just got wrapped up through fast talk labs, a lot of the names that Joe Friel discussed were names that were in this introduction in this history portion. And it’s just amazing to see how those are carrying over how the same influential people are influencing really until this day with the content that we’re creating today.

Trevor Connor  09:10

It is worth grabbing this review and looking at it just for there’s one table in it alone, where in the history part, she goes through very famous runners, you know, the Olympic champions, World Champions, through the various points in history and shows what interval work they were doing. And just think about how much work she actually had to do to find all that information. So it’s a fantastic table and you can just kind of look back through, you know, what were the top runners in the 50s doing what were the top runners in the 60s doing it was pretty interesting. But another thing that was really interesting to me in the History was they were measuring oxygen consumption and had figured out the concept of vO two Max back in the 1910s 1920s 1930s. They were doing a lot of this work. So as a A Dr. Hill that invented the whole concept of vO to Mac Archibald, AV Hill. Thank you. You skipped over the history, but you know it?

Rob Pickels  10:08

Well, I didn’t learn it at one point in my career

Trevor Connor  10:11

there was just 20 years ago. But what I found really interesting about that as well, we have known about this idea of oxygen consumption and VO two max for over a century. Now. It wasn’t until 1967. And this wasn’t for sport. This was for diagnostic purposes. Forgive me for mispronouncing that term, that they introduced the concept of an anaerobic threshold. And it really wasn’t until the 70s and 80s, that they’ve really started looking at lactate threshold, anaerobic threshold, MLSs, all these sorts of things. So we’ve talked about this before, when we’ve looked back at research that there’s this huge emphasis in the body of research, and you’re going to see this in the rest of our conversation of biller that vo two Max is central field to max is everything we just talked about. All the research was defined in terms of velocity of vO to max. But nowadays, what everybody talks about what everybody is training talks about is FTP, which is more that lactate threshold that equivalent to lactate threshold or anaerobic threshold. So we’ve kind of made a switch. But when you look at the history, VO two max and the concept of vO two Max dominated the research for a very, very long time.

Rob Pickels  11:31

Yeah, and I think that, especially as we’re discussing at this point, cyclists, right, when we talk about FTP, you know what the power meter was invented in the late 1980s. It was not necessarily in widespread use, I wouldn’t think in the mid 90s When this research and she’s reviewing research prior to the mid 90s. But as we’ve learned more, and we started to say what measures or what metrics are going to predict performance, the best than I think FTP is going to explain more of the variance in performance, it’s going to explain the difference in race results better than something like vo two Max alone. But I think that everybody recognizes and understands that vo T max is still a hugely important component in determining FTP, and not something that you can discount or discredit. Yep. But

Trevor Connor  12:17

you did raise another really important point. That is, even though Bill obviously didn’t talk about this, in this review, it’s really important to understand about the history, which was for the longest time when they were doing research on endurance sports, the focus was on running. And that was because you could put somebody on a treadmill, and you could control velocity. And since they knew what your velocity of vO two Max was, they could set percentages. So it made it easy to control studies. So in all these reviews, you’re gonna hear very little mention of cycling. It’s matter of fact, at the end of the final review that we talked about, she goes through the different endurance sports, she talks about swimming, she talks about rowing, she talks about running, she doesn’t even cover cycling, when

Rob Pickels  12:57

I was reading that I took notes on the running section, and then it was like swimming was next. And I’m like fast swimming. I’m going to skip that rowing, I’m gonna skip that. Where’s the weight, the papers done? Where’s the cycle?

Trevor Connor  13:08

It was not there at all, which is really important because with the invention of the power meter, researchers went, oh my god, here’s this great metric that we can really, really control. And you saw this switch over where now? I would say the majority of the research in endurance sports is done on a cycle ergometer.

Rob Pickels  13:28

And it’s not that you couldn’t quantify the workload that cyclists were doing prior to the power meter being invented. Right them. Monarch bicycle is absolutely classic. And, you know, I do think that initially with AV Hill and the VO to work, it was on cyclists as well. But Trevor, I think that you’re right, it wasn’t widespread use of cyclists, until really the power meter came into common place within cycling. And that was really pretty revolutionary for research. And unfortunately, we have to read about, Gosh, all these runners until we get to an era where cycling becomes more important.

Trevor Connor  14:07

Yep. So let me quickly finish up some of the key points of the history so that she goes through the different decades, and we get to the 1960s. And again, it just kind of blows my mind how recent all of this is in the 1960s. And she pays huge respect to Dr. Astron. You really start seeing the first research on interval training. Yep. And this is where I’m gonna kind of correct myself because she goes through all of astronaut’s research in the 1960s. And in previous study, I talked about short interval work 3030s 15 fifteens, that sort of thing as the current type of interval work. Where are the longer intervals were they the kind of the old school intervals? When she was talking about this first interval research? It was 3030s. It was 1515 Astron was looking at short intervals. I think the longest he looked at was two minutes by two minutes, she didn’t mention a whole lot of let’s study 15 minute intervals that study 20 mm intervals. So I think what you had at the time, and this, again goes to the difference between the lab and what was being done out on the road, was I think a lot of coaches were still having their athletes do the much longer work. But in the lab, right at the start of research on intervals, they were looking at short interval work. Yeah, sure. So quickly, getting into the 70s. And 80s. As I mentioned before, that’s where you see them starting to measure lactate threshold, try to get a grasp on this whole concept. This is also when they really started using velocities to dictate training. So this is, it was in the 80s, that they really defined this velocity of vO two Max and said, Let’s start using percentages of that. She also pointed out it was in the 80s, when we realized the importance of also using strength training, even in endurance athletes. So that’s where she gets to in the history, she didn’t really do a section on the 90s, even though this study is 2001. But I think from this point forward in the review, she’s talking a lot more about what is the current research say? And because it’s a 2001 review, I think she’s seen 1990s as current and this review. Sure, yep. So Rob, you want to take it from here?

Rob Pickels  16:20

Yeah, you know, I think that when we begin talking about the training aspect of this paper, it’s interesting, right? Because we’re looking at work that’s now 22 years old, essentially, it’s not as if there was something new and groundbreaking in here, there was a lot of little details, though, that I think are important that we review, because they really change the nature of what we’re doing today. It’s kind of like, we oftentimes, and we’ll talk about 3030s, we oftentimes discuss the big broad concept of 3030s. But there’s a lot of nuance that she talks about with 3030s, that really changed the nature of how that workout is effective for people or not. So this is why it’s important, we sometimes forget some of the things that we knew. That’s why it’s important that we always go back and re study reread re up our education, to make sure that we’re remembering all the important details, not just the details we want to remember or the convenient details,

Trevor Connor  17:19

I think that’s a really important point to emphasize here. We’ve done a few episodes in the past, and I’ll dig them out and put them in the show notes, where we talked about the focus in the research on training at 90% or higher a vo two Max and talked about that as the dogma. But is that really the where we should be going? We’ve talked about training as a percentage of vO two Max versus training based on lactate threshold, we’ve talked about all these things. But what’s important is we are talking about them as this is the dogma, this is what’s been around for a while, and essentially challenging the dogma. At the time of this review. These are new ideas. She was introducing a lot of this, this was not dogma, this was, hey, let’s look at what all the current research is showing. And this, these things would be interesting trends now. So

Rob Pickels  18:06

let’s talk a little bit more deeply about what was in this Training section, she broke the training section up into really three major sections, I’ll say the first was in discussing short intervals, these are intervals that are essentially 1515 3030s Things of that nature, then she discussed longer intervals at velocity at VO two max. So these are now intervals that are maybe in the five to eight minute range, kind of as long as you can possibly hold a workload that high. And then she discussed it’s just funny, very long intervals, which were at intensities between maximal lactate steady state, and the velocity of vO two Max. But ultimately, we’re still talking about relatively short intervals. All of these are super thresholds. So to say above four millimoles of lactate above LT to however you want to define that. And

Trevor Connor  18:58

everyone’s while she would compare it to continuous training. But the continuous training was the like to buy 20 minutes. Yep, exactly. Or steady for 40 minutes. So what a lot of coaches were actually doing at the time.

Rob Pickels  19:11

Yeah. So let’s dive in to the short interval side of things. And she opens this paper up basically by saying, making a really interesting comparison, I thought between training for four to six minutes at a time versus training in a 15 1515 seconds on 15 seconds off. And I believe it was for kind of a total duration of about 60 minutes. So a relatively long amount of time. That

Trevor Connor  19:36

blows my mind because I will tell you 1515 Or one of my go twos. Yeah, I do three sets of eight minutes. Yeah. With, like 10 minute rest in between, right. And I limp home from that workout. The idea of doing 15 fifteens for an hour now is just horrifying.

Rob Pickels  19:53

Yeah. And it’s interesting. This research really highlighted some differences between Those two workouts and what I thought was interesting was the level of lactate that the body experiences between the two of them. And in that longer interval, the four to six minute interval, the body was producing lactate of about 10 millimolar, which is very high in the whole scheme of things. When I was doing a lot of physiology testing, we would stop a test and assume that a person was kind of at a maximal lactate if they got to eight or above. And so we’re talking very high levels of lactate. Whereas those 1515 efforts were averaging about two millimoles of lactate. That is true millimoles of lactate is barely above base in the whole scheme of things, and solidly within kind of a zone three, between zone two and zone three, which is really, physiologically It’s unbelievable that there was so much difference, but repeatedly throughout this, she talks about different studies that are citing exactly the same results.

Trevor Connor  20:58

And this is what I was getting at where she seems to really be favoring the short intervals. And one reasons as she’s saying, it prevents as you said, glycogen depletion, you keep lactate accumulation low, but you spend significantly more time close to vo two Max Yeah,

Rob Pickels  21:16

the glycogen depletion side of things, I was really surprised and that those longer intervals really depleted glycogen in the type two fibers. And she proposed that the shorter intervals, the 15 fifteens, were much more taxing on the aerobic system and therefore probably better for training. Ultimately, I believe that she mentioned it was because you could recharge the oxygen that was on the myoglobin in the muscle, that you could regenerate some creatine phosphate a little bit better that you are ultimately avoiding the anaerobic contribution that the long intervals required because the long intervals burned through all your ATP, all your creatine phosphate, all of your oxygen, and ultimately were pushed into an anaerobic situation, I

Trevor Connor  22:05

actually found that really fascinating because she talked so much about these myoglobin stores. I have not read a study in the last 10 years that has mentioned that sense. And I’m interested in interested in why because it’s such an interesting concept. When we talk about anaerobic energy production, it’s constantly pointed out that you have in your muscle cells in ATP store. So you can work for several seconds, just on that store of ATP before you have to start producing ATP. This is kind of the aerobic equivalent, which is the myoglobin already has oxygen bound to it. So you have this availability of oxygen that you can use before you have to start delivering oxygen. And

Rob Pickels  22:49

for those who are unaware, I’m sure that people are familiar with the term hemoglobin, right. And that is a molecule floating in your bloodstream delivering oxygen to all of your tissues, not just your muscle. Whereas myoglobin, the Myo meaning muscle is essentially like a hemoglobin that is locked inside the muscle. And it is able to hold on to oxygen there. And I believe at one point she mentioned, the myoglobin was able to provide oxygen directly for about half of the 15 second interval just based on the stores in the muscle itself. And then it was able to be recharged in the very frequent rest periods that were occurring, right.

Trevor Connor  23:27

So the idea is if you do those longer, four minute intervals, you deplete the myoglobin and it’s just depleted gone, where you do the 1515 mins, and that myoglobin can keep at least partially restock, and it’s oxygen.

Rob Pickels  23:40

Exactly. And the thing that supports this that blew my mind was the fact that they said lipid oxidation was higher in the 15 fifteens, as opposed to the four to six minute intervals. Right? What I was so shocked to read that and I’m not in disbelief. It was just one of those things like these when I talk about the basics and the nuances that we need to go back and re understand. This is the detail that I’m talking about. Yeah,

Trevor Connor  24:06

and it is fascinating. So she is painting this picture. And I think where she really landed I mean the intervals she seemed to love with a 3030s with an asterix that if you do a complete rest in the 32nd rest, you never actually achieve vo two Max, so you need to have an act of rest in that 32nd rest. But she said as long as you’re doing that, you have this great scenario where you are spending significantly more time at or close to vo two Max, you’re not accumulating lactate. You’re burning more fat. What an amazing aerobic No,

Rob Pickels  24:42

no, it’s true in that you just mentioned the other caveat that I was thinking of when I gave that in the in the intro. We talk a lot about 3030s but we oftentimes don’t necessarily talk about the actual prescription of 3030s and it is overwhelmingly important that that recovery is an active recovery. And they found that that being at 50% of your peak or your hard workload was about the right place, that you can get enough recovery that you can continue doing these one after another. But that you’re also keeping that oxygen consumption high throughout the recovery period. And she pointed out that in the research, they were able, they studied up to 1830 30 efforts in a row. And it seems like subjects were hitting view to max at about the fifth interval. And then they were maintaining from the fifth to the 18th interval. So essentially, they said, 85% of the time, if I remember the percent rate was spent at VO to max, and that is about as high as you can possibly get. Yep,

Trevor Connor  25:49

no other than just a side point that I love. Because it was right about this point in the review. Again, we did a little study about this is this concept of training at 90%, or higher vo to max, an effective way to train but we were saying, you know, this is what the research is focused on forever. It was like page 23 or 24. In this review, she kind of presents it as this new concept. Yep. So you can see there, this is when they were thinking about these sorts of things.

Rob Pickels  26:16

Exactly, exactly. So I want to touch you know, at this point, we’re kind of blending the different sections as we have the conversation. But I want to keep going on this percent of time at VO to max, right, because to point out the opposite, when we talk about the longer intervals at say 100% of the velocity or the power at VO to max, an interval where you’re doing four to six minutes of work, it takes multiple minutes to get to a vo to max level. So you might be doing that for five minutes. But you might not hit vo two Max until three, three and a half minutes in, which means out of that five minute effort, you’re only getting a minute and a half or so of time at VO two Max. Whereas in those 3030s. If you’re able to continue boom, knocking them out, then you’re able to maintain that level. And because you’re not depleting all of the stores like you are in the long effort. You don’t need the long recovery like the long efforts require.

Trevor Connor  27:14

Yep. And I mean, she paints a pretty bleak picture of these long intervals. She’s like, Yeah, you don’t improve your time a vo to Max, you accumulate a ton of lactate. Yep. You know, just it’s not sounding too positive, right down to the fact that she spent pages on the short interval, she gets a long intervals. And I’m not even sure it was a full page. Yeah, the one thing that she does talk about in the long intervals, and probably will be short on this here, because we’re going to cover a whole study about this is she talks about, they would do tests with athletes, where they would have them run at their velocity at VO two Max and test how long they could sustain. So that would be your time limit at the velocity at VO two max. And she talks briefly about the benefits of doing intervals at half that length. And really customize it to the individuals because what you’ll see is some individuals can only go like two, three minutes. At that velocity other individuals can go 678 minutes at that velocity. So if you do kind of have that velocity, you’re going to achieve vo two Max, but it’s individualized to you. Yep,

Rob Pickels  28:25

definitely. So she also discussed and we haven’t brought it up at this point, there was very long intervals. And they termed it it was like what like the Delta 50 Exactly that. Excellent. I’m glad you had that on the tip of your tongue.

Trevor Connor  28:40

Thank you. I’m looking right at it.

Rob Pickels  28:41

Do you remember when that term also came up? Trevor in an episode that we did? No,

Trevor Connor  28:46

I don’t. When did we cover that? Oh,

Rob Pickels  28:49

if you remember back we talked about Ben Ron stad. And his variable workload vo to max intervals. The low part of the variable workload was at this sort of point right right halfway between your maximal lactate steady state and your VO two Max. I just found that interesting that that connection I wonder if he was in when he chose that workload for his research. I wonder if he was influenced by some of this research that she’s referencing here.

Trevor Connor  29:21

That’s a really good point and be interesting the other thing on that note that I’m interested in this review, which she didn’t fully answer even though she uses verse both terms, there’s another important number so you will hear about critical power in cycling. But there’s also critical velocity and that’s defined as the lowest velocity at which you can still obtain vo two Max correct yes. And it is in between your maximal lactate steady state and your VO two max. So the question I have is this v delta 50 which is right halfway in between and critical velocity How does They relate to one another and how close are they to one another.

Rob Pickels  30:02

And I’m answering this based off just of my general knowledge and nothing I’m not referencing any material. In my understanding, the 50% mark that we’re discussing now is a higher workload than critical power or critical velocity. And oftentimes, the critical power velocity is, is a few percent above, where maximal lactate steady state is. Whereas the 50% is going to be a bit higher than that,

Trevor Connor  30:29

which is fair. She does point out, though, that intervals at critical velocity are generally done at about anywhere from four minutes to six and a half minutes.

Rob Pickels  30:38

Oh, really? Yep, that’s much shorter than I would have expected. Well, part

Trevor Connor  30:42

of what she talks about here is if you just do continuous work at critical velocity, or V delta 50, she’s like, via just it just doesn’t do much for you don’t spend much more time with VO two, Max when he says, What happens if you do intervals at those intensities. And so she raised that as a time period for doing these intervals and said, that can actually double the time that you spend it via to max, when you do intervals at critical power.

Rob Pickels  31:09

Now, it’s interesting when she was discussing these really long intervals, she brought up the concept of the VO to slow component, and did mention that eliciting that slow component could actually be an efficient way of training your VO to max. But what was interesting, as she pointed out that elite athletes don’t necessarily exhibit a slow component until they’re at a relatively high percent of their view to max already.

Trevor Connor  31:36

Yep. So I point this out to athletes all the time. And you see this action and heart rate. And yes, she does say in the review that you have to measure vo to that you can’t measure heart rate for this. But I can argue slightly differently when I have an amateur athlete and I give them say, a five minute interval at these sort of intensities. What do you see with heart rate and this is explained to the slow component. First, it rises very rapidly up close to their threshold heart rate. But then over the course of the five minutes, you’re gonna see a gradual rise in that heart rate that’s never going to level

Rob Pickels  32:08

off. And for what it’s worth five minutes ought to be enough time for somebody to reach a steady state. So it’s not like it’s just climbing up to the value, it’s going to get to right already sort of plateaued. And now it’s ticking up one beat sort of at a time right.

Trevor Connor  32:22

Now, if I give the same intervals to an elite athlete, obviously, it’s going to be at a higher velocity if you’re a runner or a higher power if you’re a cyclist, but relatively, it’s the same intervals, what you see is the heart rate, you have that rapid rise in the heart rate, and then it just flattens. And for that five minutes. It is a flatline. Now you finish interval and then it drops down again. Yep. And that’s one of the ways you can see improvements in training is if you can just flatten out those intervals. And

Rob Pickels  32:51

for those who aren’t familiar with the slow component, Trevor previously talked about critical power or critical velocity being the lowest workload that will eventually elicit vo two Max, it eventually elicits vo two Max because of that slow component. Right? Let’s say you go out and you start pedaling at 300 Watts, and that takes 52 milliliters of oxygen per kg per minute. Normally, if that was below critical power, you could sit there for 510 minutes and it will just sit at 52 there about if that’s above your critical power, it goes 50 250-354-5556 And then eventually you hit 58. And that’s what your VO two Max is. Yep.

Trevor Connor  33:33

So she kind of hints at the fact that in amateurs you can use these longer intervals you can get them to vo two Max and get a good training effect. But I do feel that she was hinting at in those elites. You need to do those shorter, more severe intervals because that’s the only way you’re going to elicit vo two max. Now

Rob Pickels  33:49

certainly. Anyway, I have an interval workout today. You know, I’m doing 3030s

Trevor Connor  33:54

You love the shorts. So I do both. Yeah, so I do the longer stuff in the winter. I do the shorter stuff during the season.

Rob Pickels  34:03

I did a swift race the other day who first one and a year. Oh, did you knock my legs off?

Trevor Connor  34:08

I started one last night. I started while I was second last time the crossing the start line. I was like three minutes back. Awesome. Love it within 10 minutes. i Yeah, I’m not ready for

Rob Pickels  34:21

my God. All right, Trevor.

Trevor Connor  34:24

So here’s what I found interesting. She then gets into the long term effects. What are the adaptations we see to all this after she has painted a very clear picture that short intervals seem to be magical. These 3030s are incredible. long intervals a whole lot of pain, a whole lot of lactate accumulation. Don’t spend a lot of time at VO to max. So then she gets to what’s the adaptation that we see and I was expecting her to go man who was amazing what the 3030s and it wasn’t that. So this is on page 27 quote, the VO two Max improvement was significantly higher for the long interval training and the continuous running so about a 6% improvement, versus the short interval training about a 3.6% improvement. And I had to double read that. So I’m like, even go on this one way, and then you show this result. And it’s saying the exact opposite. And further on says the largest increase was seen in the continuous run group, when time to exhaustion increased by 94%, from 35 to 68 minutes, for long interval training increased by 67%. And for short, interval training time to exhaustion increased by 65%.

Rob Pickels  35:36

One thing I want to point out, though, Trevor, I think that’s important is the next sentence that was after the first part of what you said. And that was the rest this could be because of the fact that the rest more complete in the short interval. So I think that for that particular study that’s being referenced there, it shows the power of maybe the inappropriate 3030 workout prescription, and that if you do allow complete rest, you’re not taxing that vo two Max anymore, so

Trevor Connor  36:06

I’ve read that too. And okay, so now she’s gonna bring up other studies where she shows the opposite, and she doesn’t. So it might just be they hadn’t done those more effective research. And she’s the one pointing this out. But it was very interesting that this was a study she brought up to show the adaptations and it’s telling the exact opposite story.

Rob Pickels  36:23

Well, and I think that we have to understand right that both of these workout methods have shown to be effective over time. And it’s not as if you know, Dr. Seiler, right? has amazing research that shows eight minute intervals are the creme de la creme, he wouldn’t say that. But he actually hates when we say stuff like that. But it’s not as if they’re not effective. But what I do take away from this is perhaps if the 3030s are as effective, equally effective, but they are inducing, say the lower lactate and have these other positive things, does that make them potentially more useful in certain situations, if you’re going after a certain effect, or you’re trying to cause certain adaptations, where you’re trying to say, alleviate maybe the stress on the body? It’s shades of gray right when you’re making choices. So I

Trevor Connor  37:15

think where this all leads to, and I think we’re on the same page here and agree. Remember, this was a 2001 review. And she is pointing out stuff that’s now just accepted, but wasn’t really knowing than is really advancing our understanding of interval work. But there were certain conclusions she couldn’t draw. And she in the conclusions of the study, she says that she literally says, it is an important but unsolved question, which type of training is most effective to maintain a level representing 90% of vO to max for 40 minutes, or to tax 100% of the VO to capacity for about 16 minutes? Today? This is still an open question.

Rob Pickels  37:57

And I think that’s exactly where Dr. Randstad was when he was doing his time at 90% as being a very effective measure. And his conclusion based on that research was racking up as much time above 90% is the most important when you’re designing a vo to max level workout.

Trevor Connor  38:18

Hey, cycling coaches this is Trevor Connor, I’d like to invite you to ignite your spark at the 2024 endurance exchange. This year’s event is powered by USA Cycling and USA Triathlon. It offers new info and great networking opportunities mix it up with hundreds coaches from around the globe and soak up forward looking talks from renowned experts like keynote speaker Dr. And Hugo Samba lon I’ll also be there sharing my insights and how to choose reliable and trustworthy info in a world of information overload experience the endurance exchanges January in North Carolina for more information go to endurance Damn, Rob, we are 43 minutes. So I really dived into so we might have to fly through this study that she did in what was this 96

Rob Pickels  39:09

If you want to do the 99 Oh, you want to do the VO two? Yeah, cuz

Trevor Connor  39:13

it does relate very much to what we were just talking about. Yep. So I’ll give the the very quick methods on this. So she was really trying to look at two things in the study. One was this idea that I mentioned before, which was if we base interval work, so have runners run at the velocity of vO two Max, but base the intervals on half of the time to exhaustion at velocity to vo two max. So every runner is going to do a different length interval.

Rob Pickels  39:41

And I want to emphasize what you’re saying right now because oftentimes we would do something like you should do four by four minutes at 120% of FTP. That’s a great workout. It’s a universal workout. Now, take two different athletes and I bet me and you are maybe a little The difference in this regard, right 120% of FTP athlete, one might be able to hold that for four and a half minutes and athlete two might be able to hold that for eight minutes. Is that the same workout for both people when you use the same four by four minute prescription in her mind, it’s not. And that’s what this paper is upright.

Trevor Connor  40:18

And what she’s getting at is that if you prescribe the same interval and use the same length for two athletes, it might be perfect for one athlete, it might be burnout, material for the other athlete because one athlete let’s take the classic five by five minute vo two intervals. For one athlete, you know, their time limit of vO two Max might be four and a half minutes. So they’re going over their time, every single time exactly. And dime the other athlete, their time limit might be eight minutes. So they’re doing a hard workout, but they’re not going to their limit. And it’s going to have a very different effect. And I

Rob Pickels  40:51

think that this concept that people can hold that vo two max power for different lengths of time, I think that that’s lost. I think everybody assumes your view to max power is the power you can do for four minutes, or whatever the number is. And that’s not the case, when you’re testing people in the lab. Yep, everybody

Trevor Connor  41:07

is different. So that leads to the second part of this study, which was looking at if you individualize it, does it still push an athlete into overtraining? Yep. So the way she did this is they did four weeks where the athletes were doing one of these interval workouts at the velocity of vO two Max a week and then one interval at OBL is basically a threshold workout, then they took a rest. And then they did four weeks where they were doing three interval sessions at the velocity of vO two Max and still doing the one overall a workout. So this was a should be pushing overtraining block and doing that for four weeks.

Rob Pickels  41:49

Yeah. And to point out there was in the first in the normal training session, in addition to the two interval workouts Trevor described, there were four sessions of endurance. Those went down to two sessions of endurance in the overtraining when they added the two additional intensity days. And if I remember correctly, that overtraining had kind of been a validated overtraining method that had been used in previous research, kind of like, we know that doing this for this length of time causes these overtraining markers.

Trevor Connor  42:21

And basically the way to think of this is since you’ve mentioned Dr. Sylar, Dr. Sylar would look at the first four weeks here and go, What a nice prescription. And he will look at that second, four weeks and just go what what, what are you doing? That’s, that’s gonna kill the athlete. Yeah, but

Rob Pickels  42:36

Block Periodization might say that that overtraining week is exactly what it should be. Well,

Trevor Connor  42:41

but it’s four weeks, that’s okay. That’s only one week of that. That’s fine. I was like four weeks of that details. So let’s, let’s fly through, I’ll just kind of give the highlights of the results. So that first four weeks with just the one session was called the normal training, the other four weeks, I love the fact that like, you can see their bias they called it the overtraining period. So OT, the normal training block at the end of it, you saw improvements in their velocity at VO two Max, you saw improvements in the running economy, but their actual vo two Max did not change, right. And so it’s quite possible that the improved running economy is what allowed them to run faster

Rob Pickels  43:24

that the velocity of each mess. Exactly. They were doing more work for the same amount of oxygen. Yep.

Trevor Connor  43:29

So now let’s talk about the overtraining period. You did see an increase in norepinephrine after an exhaustive workout. So there were definitely some markers that they were they were going into an overtrained state, but ultimately, their subjective rating wasn’t high enough to say yes, this is overtraining though their subjective rating of soreness was very high. But the key thing here is there was no further improvement in their velocity at VO two Max. They maintain what they achieved during the normal training. They didn’t improve any further. But they you also didn’t see that decline in performance that you would expect from being overtrained? Yeah, I

Rob Pickels  44:09

think that there’s a couple takeaways here, right? Where training is good, normal training is good. You can get amazing improvements off the standard stuff that we prescribe and recommend every day. Additional training on top of that is not always better. They did you know what, three times or at least twice the high intensity work but they did not see commensurate improvements in vo two max or these other measures. But at the same time on the opposite side of that when answering the question or a question that she had set out to answer by individualizing this workout protocol in a known workout method that should have overtrained people. Granted there was some increase in norepinephrine but we didn’t see some other changes that you would expect to see in an acute sense with overtraining, maximal heart rate stayed essentially the same, maximal lactate stayed essentially the same. And I will say that from somebody who’s done a lot of physiology a lot of lactate testing, a decrease in maximal lactate is a very early indicator that somebody is heading off into the overtraining state. And so to see that those metrics haven’t necessarily come down, even though performance didn’t get better, to see those didn’t come down, is really saying, hey, this individualized method that she’s talking about might have something to it in terms of not just burying some people into the ground. Yeah.

Trevor Connor  45:35

And what I love about this is, you know, we talk about training software. So you go back to the history of Wk, oh, and training peaks, and golden cheetah and all the software, when it first started coming out. I think this software was coming out in the late 90s, early 2000s, there was really no individualization like everybody had basically the same training zone just based on on one metric, interval prescription, a lot of the work that you saw athletes doing again, was not individualized it was, you know, five by fives, that’s great for improving that serve two by 20s. So this whole concept of individualizing to each athlete feels like this new thing, like, you know, now you you’ve heard Hunter Allen and Dr. Coggins, talk about the whole new training zones that really look at your profile. So your VO two Max relative to thresholds can be very different from another persons. And it also looks at this duration, you know how long you can sustain those that you think of that as a new concept. I’m sorry, I didn’t explain that very well. But I love his here you have a 9099 study where that concept of you got to individualize to the athlete is being introduced.

Rob Pickels  46:47

And again, it goes back to that we always have to be reviewing some of this old information to remember the things that we forgotten. You know, Trevor, I agree with you in that workout prescription right now is oftentimes not individualized. And I want to bring up I use a few different training platforms, especially throughout the winter when the weather isn’t so good outside. And years ago, Neil Henderson had created along with Matt Casson, this four DP sort of profile. And what’s unique about that is and if there are other platforms that have this, and I don’t know about it, my apologies, it’s just I don’t use that platform. And this was something that they had created and incorporated into suffer fast and then suffer Fest was bought by Oahu, and now it’s become Oahu, x or whatever. But in that there are individual sort of ranges for threshold efforts for Sprint efforts for vo two efforts. And it’s not like other platforms, where it’s just like, Oh, 120%, from me, who’s somebody who’s very strong above my FTP, my numbers are relatively high compared to other individuals. And I have always, as an individual had to say, when I do a 20 minute test, I multiply that number by point nine, two, not by point nine, five, because I know I’m stronger at 20 minutes than I should be based on what my FTP is. So this individualization, it doesn’t happen enough. And this is the only platform I know that’s doing it, and it’s not a promotion of of Wahoo is just to point out and say, Hey, I only know of one that’s doing this right now. But it’s been an important metric for a long, long time.

Trevor Connor  48:24

And you see the differences in people. So you point out, you’re like, I love to point out when I do that test. So you do the five minute vo two max test, then you take a break, and then you do the 20 minute threshold test. It looks like I’m just doing a 25 minute break in between.

Rob Pickels  48:39

It’s just not that different. Yeah, exactly. Right. It’s funny. So

Trevor Connor  48:42

the only issue I had with this study, and it’s a very minor issue. She points out in the introduction that a lot of coaches at the time, would do normal training for a while then they would do a four week overload with their athletes ahead of the season to get those last little gains, and then they would rest the athlete and take them into the race season. She did her tests after the four week overload only a week later. But even points out that the coaches do that much earlier relative to the season, the athletes get several weeks to rest. So would have been interesting if she had done the testing several weeks after the overload period, because I don’t think the athletes were fully rested a week later. And you might actually have seen some gains if he had waited a few weeks.

Rob Pickels  49:29

And so ultimately, this discusses the topic of super compensation, right? Where we know that when somebody does hard work, their performance immediately it goes down. You do a hard workout yesterday and then you do a maximal test today, you’re probably going to be worse for it. You do that for a couple weeks. And then you take that recovery, you let the body repair in the hope is that you come back above baseline. And so you’re sort of proposing that one week they might not have had that compensation. And they might still be on their way back up, and that we would eventually see better performance giving a little bit more time. Agreed?

Trevor Connor  50:05

Well, Rob, we’ve been covering a lot, we still got one giant review to cover here,

Rob Pickels  50:12

lactate lactate.

Trevor Connor  50:15

And what I love about this, as we just talked about that first review, where I was saying, you really see the focus on vo two, Max, that review was 2001. She doesn’t really talk that much about lactate in that review, correct. But here’s a review. That’s five years earlier. That’s about lactate. And here’s my hot take, I’m going to bring this up. Were in that first review, where she’s talking about intervals and velocity of vO two Max, she’s introducing concepts that are now considered really the, you know, at the forefront of the science of interval training. These are still relevant concepts in this review, where she’s talking about anaerobic threshold and lactate accumulation. And talking about the physiology behind it, you really see some outdated concepts if he hands me.

Rob Pickels  51:04

Yeah, I struggled with that a little bit. And I think that she was without explicitly saying it like she did in the 2001 paper, I think that she was kind of going through the history, not necessarily making statements about what she believed or what the current was, but just sort of talking about the different ways of thinking. And there was one point where I was reading and it highlights exactly what you’re saying, where I was like, this doesn’t square with what I know. And I had to double check dates. I was like, Was this before Brooks proposed lactate shuttle? And it wasn’t because he proposed I’ve mentioned Brooks a couple of times, eventually she does. But in the beginning she hadn’t when I was reading some of that. So that’s why I think it was little bit more of a historical thing, because Brooks’s lactate shuttle was 1985 was the first time I could see that term in this paper was in 96. And she did eventually get to talking about Brooke. So I do think it was a little bit more of a historical perspective. Yep.

Trevor Connor  52:00

The other thing though, that I really like about this is again, you see her love of vO two Max and velocity of vO two Max and that other review. This one, she starts out like first paragraph. There’s a lot of controversy around blood lactate. We don’t really know if it’s physiological. And this is where Dr. Sol Milan somewheres cringing because for him, it’s all about lactate. If he could create a lactate meter on the road, he would throw power he throw it heart rate, everything. But she’s like, Yeah, we question the physiological basis of this. It doesn’t really represent production. Like she basically bad mouse said right at the start. And that goes, but yeah, let’s go ahead and review this. You don’t see the love for lactate threshold that you saw for vo two Max. Yeah, certainly. So it all kind of starts she goes into this concept of anaerobic threshold and lactate accumulation. We’ve talked about this on the show. And you’ve heard some very current physiologists get very angry about this. But she starts by defining, there are two states, there’s the one state and again, I’m going to preface this by saying this is outdated. So I’m not stating this is just what’s in the review. She says there’s this sustainable low intensity, where lactate doesn’t accumulate, where you are producing your energy aerobic Li, and then you hit a certain point, which he calls the anaerobic threshold, and that above your anaerobic threshold, it’s no longer sustainable. You’re accumulating lactate, and that’s because you’re bringing in glycolysis to produce energy. Now, again, that’s very outdated. We know you’re using all these different energy systems all the time. It’s just ratios. So this is that older concept of your aerobic until you hit anaerobic threshold, then you’re bringing in all this anaerobic metabolism.

Rob Pickels  53:56

Yeah, it’s interesting to in that first area, the sustainable at a steady state. It says and I’m reading from the paper right now, exercise is limited by the increase of the internal temperature associated with dehydration prevented by supplementation of water and substrate. in some regard, those are limiting factors, but I’m not gonna say that they’re the only limiting factors and then it says, You go above that, and you’re in this nonsustainable, and there it says, exhaustion and fatigue through the disturbance of the internal biochemical environment of the working muscle and whole body caused by a high or maximal acidosis. And that might not be completely accurate. Yes,

Trevor Connor  54:34

there are a few inaccuracies. Here’s I’m glad you pointed that out. One thing she does point out that you know, absolutely makes intuitive sense, but it was just nice to read it that I had to kind of just think about for a minute because you’re going to start when you look at most training zones. There is a training zone that is between your VO two Max and your anaerobic threshold. Yep, so in a lot of systems, I think that zone five, but you have these two key points your VO two Max and your anaerobic threshold. She points out that lactate accumulation doesn’t correlate with VO two, that they’re two different things that you’re measuring. And they don’t really match up with one another. So when you think about that, we have this lactate threshold, we have this vo two Max, but you use two different systems to identify them. And those two systems don’t fully correlate. So it’s kind of to use a metaphor. You’re mashing apples and oranges together to come up with our training zones.

Rob Pickels  55:39

Yeah, no, certainly. And we can’t necessarily define what we would otherwise call the VO two max by a lactate measure. Right? For some people that’s at six millimoles. For some, it’s at seven for eight. It’s not like we can identify something on a curve like we can on the on the lower part of the profile. And so you’re almost forced into doing that. But it is important to point out that yeah, we’re measuring two totally different systems.

Trevor Connor  56:04

Right, she points out vo two Max is based on oxygen delivery. Lactate accumulation. lactate threshold is based on glycolytic flux. One is aerobic one is anaerobic. No, no, I just found that very interesting. So where do we want to go to next? Yeah,

Rob Pickels  56:21

I think that she covered some great basics. And I’m just going to throw them out here. You know, lactate and performance, like I was talking about earlier, about 92% of the variance in performance is explained at this sort of lactate threshold, which is very high. What I found interesting, you know, lactate, in untrained individuals, that lactate threshold is improved within two to three weeks. And that ultimately, slow twitch muscle fiber count contributes very, very highly to how high your lactate threshold is. Now, what was super interesting to me, and I’m jumping around a little bit, children, pre puberty, children produce significantly less lactate than adults do. And I had always and maybe this was just me misunderstanding. So I’m gonna bring this up really nice. I had always, in my mind apparently assumed that children were more anaerobic than they potentially actually are with their low levels of lactate production.

Trevor Connor  57:17

So that is what I’ve been taught to, which is there’s no point in training pre pubescent kids in endurance sports, because they don’t really develop that system until after puberty. But she’s pointing out, they seem to be absolute aerobic animals. And after

Rob Pickels  57:32

they hit puberty, then lactate shoots through the roof,

Trevor Connor  57:35

right? What the heck. So yeah, I would love to dive deeper into I don’t have an answer for you. Because I have the same thing of weight. That’s the exact opposite of what I thought,

Rob Pickels  57:43

yeah, exactly. Now, I will say I don’t necessarily believe in training, quote, unquote, somebody prior to puberty. I love that kids run and my kids run, and they ride bikes, but oftentimes, it’s fun, it’s not intervals. And so I do think that we can apply a lot of our training principles to what I’ll call a junior athlete, somebody in that 1415 to 18 year old range. But when we are talking about somebody who hasn’t gone through puberty, yet, their physiology is very different. And maybe we don’t quite understand that as coaches. One

Trevor Connor  58:16

important thing she pointed out there is there, lactate levels are completely different. So this is an earlier review. And again, this is something that’s a little bit outdated, but for a long time. They basically said your lactate threshold is at four once your blood lactate levels are four millimoles per liter. And they kind of said that’s it for everybody. We now No, no, that’s different. Yes, some people are higher, some people are lower, you can’t use that. But she wrote this at a time when they that that was well believed. And she even brought that up. But she points out that you might not be able to use those numbers and children that actually in children. lactate threshold might be closer to 2.5.

Rob Pickels  58:55

Yeah, yeah, she directly said about two and a half millimoles and children equates to about four millimoles and an adult. And you know, Trevor, it’s interesting that you bring up this concept of the four millimole is a threshold, oftentimes that’s referred to as Old Blood, the onset of blood lactate acid. In this review, she points out another metric, maximal lactate steady state and Frank Overton when he had his physiology lab was a big proponent of MLSs. And MLSs is essentially, if you take serial lactate measurements over time at one workload, meaning let’s say you go out and you ride at 200 Watts, and you test it five minutes, 10 minutes, so on and so forth, that you stay at 2.2 millimoles the entire time, and then you bump that up to 220 Watts, and then you test and it’s two and a half 2.6 2.7 And it keeps on climbing, then you’re above that maximal lactate steady state. Something that she talks about in here is that that maximal lactate steady state can occur anywhere between two and seven millimoles of lactate when traditionally we Think about lactate threshold being ultimately in the three and a half to four millimolar range.

Trevor Connor  1:00:04

So it’s all over the place. By the way, one other thing I want to point out about the kids that couldn’t get out of my head, is, you know how difficult it is to get adults to follow a prescription. I am picturing a study where they have 10 year olds, and they’re like, We want you to run at this exact velocity. And then we’re going to prick your finger every three minutes, and take your blood. Like I want to find that study. Because I bet you in the study and the methods, it says, we started with 30 children, we lost 20 of the children because they started chasing butterflies.

Rob Pickels  1:00:37

No, Trevor kids are easy, just hold some candy in front of them, they’ll do anything you want. A maximal test for a child is just a pack of m&ms slightly out of reach.

Trevor Connor  1:00:50

So another interesting thing she brought up in this review, which is again, a very now a very established concept, but I think was very new when she wrote this review is his idea that one of the biggest training effects you see in endurance athletes is you see a rise in that lactate threshold relative to vo two max. So again, it’s well, it’s hard to improve your VO to max, in elite athletes, their lactate threshold gets very close

Rob Pickels  1:01:16

to it. Yeah. And ultimately, that ties to performance, right? Because it’s essentially indicating that you are oxidizing fuel at a higher rate relative to your maximum. And ultimately, that means that all of those higher workloads are more sustainable than if you’re in a glycolytic situation and producing a lot of lactate. And you’re not gonna be able to hold quite as long because of the changes in metabolism.

Trevor Connor  1:01:43

So here’s where I found the review. Interesting. And it goes. And again, I just point out, this is a 1996 review. Remember, when you’re talking about that 2001 review, and she was given the history, it was really only in the 80s that they started studying lactate threshold and how to measure it. So she has a whole section where she talks about incremental exercise of basically testing for lactate threshold. And you realize as you’re reading this, most of the research that’s been done in this was after this review, okay, yep. So what she’s covering doesn’t have the benefit of what we know now. And so she actually talks about individual anaerobic threshold IA T, which I haven’t heard uses in a long time. And she defines it as the maximal production of lactate, where you can still clear at the same rate, which to me is the definition of MLSs, maximal lactate steady state. But she does compare them and say they’re very close, but not quite the same thing. Interesting. So I’m not sure how they differ. But when she’s talking about testing, you don’t hear the usual you know, three minutes stages and how you measure them back. Tests, like we do know, yeah, she kind of touches on it, but you can just tell there isn’t the understanding that we have now. So the two things that she covers is one, the Borg scale, which is that how hard do you feel you’re going and points out that the Borg scale actually correlates really well with lactate levels? And

Rob Pickels  1:03:13

this is the original Borg scale this six to 20. Borg scale, I will point out,

Trevor Connor  1:03:18

Yep, great. And then the other interesting thing was, where she lands on is determined MLSs. And, you know, I was surprised how developed this was in the mid 90s, versus some of the other testing methods because the MLSs, it is one of the most brutal tests that you can do, because you have to basically exercise at certain velocities or powers for about 30 minutes. So you do a 30 minute test, and then you come back like two days later, you do another 30 minute tests, come back two days later, do another 30 minute test. They’re all right around where we think your LMS says. And then what we’re looking for is the one where your your lactates stay level.

Rob Pickels  1:04:01

Yeah, if I remember, right, for Frank’s protocol, it was day one was more of a normal incremental test to understand the ballpark. And then day two, you came back, let’s say they think the ballpark is 250 Watts, you would then come back and do 242 5260. And you would really do these longer efforts, dialing it in. But think about you’re doing all of these efforts right around your M L S. S, that’s really taxing to do sustained intervals.

Trevor Connor  1:04:29

You’re doing five, six, basically threshold time trials. Yep, exactly. So it’s hard. It takes a lot of time that interferes with your training, you’re gonna get a very accurate number, but then training of that number might not be accurate in a month or two.

Rob Pickels  1:04:41

Yeah. You know, something that she brought up in this paper that really carries through today are some of the absolute values and these apply to running and race distances, but pointed out that marathon has often completed between two and three millimoles of lactate, men at Boulder Center for Sports Medicine. We oftentimes use a two and a half millimole. As a corollary for this is about your marathon pace. And I will say I do a lot of lactate testing on my wife, Melissa, and it correlates pretty well to her marathon paces. So that carries through today. And she pointed out that a four millimole measure is oftentimes around what people can hold for a 10 to a 16k.

Trevor Connor  1:05:21

So you already talked about children? She also talks about are there differences in women. And what again, I found a dress in here, she didn’t really even though there’s a whole review about lactate, she doesn’t talk that much about lactate. So she does point out, you don’t really see differences in women in terms of that percent of vO two Max and mitochondrial density, but women actually have a superior running economy and higher aerobic reliance. So when they’re training those, you know, subfield two paces or sub threshold pesos they they’re using a lot more fat than than men are

Rob Pickels  1:05:59

in it is interesting, because I feel like today we are talking about the fact that women have better economy, again, as if it’s a new concept, right. And it’s something that she had brought up many years ago that women have better economy than men is it is how it is physiologically speaking. But yeah, at this time, and I’m failing to think of any more recent research, so I’m just going to reply based on what she’s saying. That threshold is occurring at about the same percent of vO two max for men and women.

Trevor Connor  1:06:28

The other interesting thing again, this was just one study, they looked for metrics that would predict performance and male runners, and found four that pretty much predicted 96% of performance. And in that same study, they basically said, We found nothing that correlated with performance in women. But she does cite other studies that say that onset of blood lactate accumulation. So that’s another way of finding round that threshold is a predictor in women. Listeners, this is a great time of year to expand your training knowledge join fast talk laboratories now for the best knowledge base of training signs and topics like polarized training, intervals, data analysis, sports, nutrition, physiology, and more. Join fast talk labs today and push your thinking and your training to all new heights. See more at fast talk.

Rob Pickels  1:07:25

Let’s talk about masters. Yeah, this, this applies to you. It’s starting to apply to me. Yeah, welcome

Trevor Connor  1:07:31

to my God, it’s

Rob Pickels  1:07:32

getting there too quick. It was interesting that lactate we just talked about lactate as a percent of vO two max for men and women. For Masters athletes lactate as a percent of vO two Max can actually increase. And it’s not necessarily for good reason. It’s because we’re able to maintain our lactate threshold better than we can maintain our vo two max. And so as we age that vo two Max is coming down. lactate threshold is coming down less. And the percent looks better. But I don’t know I think I’m going to keep working on my vo two Max and try to make sure it doesn’t come down much now.

Trevor Connor  1:08:10

And she points that out that this is why you can see athletes in their 40s where they can’t match younger competitors in a two three minute effort. Put them in a 30 minute time trial and they can still do world class performance. Sure.

Rob Pickels  1:08:23

Yep. I mean, I was never world class for 30 minutes, but whatever.

Trevor Connor  1:08:27

World class for 15 seconds.

Rob Pickels  1:08:30

Maybe not world class, but certainly better. I still love the

Trevor Connor  1:08:33

fact that half the videos that we use for fast talk labs, share that video of you and I sprinting together me Do you absolutely destroy me.

Rob Pickels  1:08:45

There was what we were doing that I remember looking back at one point like Did he break his bike? Like where is he? My

Trevor Connor  1:08:50

favorite part is when you watch it from overhead. It looks like I just quit the fact of matter that I know. I didn’t quit. It just looks like

Rob Pickels  1:09:01

yeah, because you can go that speed forever. So you didn’t stop? Nope. Yeah,

Trevor Connor  1:09:06

it was it was sad. It was very, very sad. So I think let’s just cover a couple of minutes. We already addressed the fact that again, going back to 1996. She goes through the different endurance sports so she has a whole section on runners. A whole section on swimmers a whole section on rowing, nothing on side, nothing on cyclists. And you know, there were a few interesting points, but I think we can jump through this. Actually I found when she was covering runners there wasn’t that much that was new because the previous review and this review so much of the research was always on runners. It was just kind of a summary of everything we just talked about swimmers what I found interesting is because of the drag that you get through water, they’re MLSs their pace and MLSs is very, very close to their pace at VO two Max.

Rob Pickels  1:09:55

Well, yeah, I mean because the hydrodynamics of that array All right, think about an i don’t know I’m pulling this out of thin air aerodynamics, it’s cubed power is cubed with velocity. So every

Trevor Connor  1:10:08

kilometer an hour faster. The power required is cube. Exactly.

Rob Pickels  1:10:12

In swimming. It’s got to be some ungodly high thing, because you’re going through such a thick medium, right? Yeah. And

Trevor Connor  1:10:19

sorry, I just want to correct some people might misinterpret me it’s not. Let’s say you’re going at 20 kilometers an hour, and you’re doing 200 watts. It’s not that to go to 21 kilometers an hour, you have to put out 600 watts. It’s if you take the increase in wattage you had to use to go from 19 to 20 kilometers an hour. Correct. You cube that and that’s the increase you need to go from 20 to 20 squadrons great call out just to make sure people don’t quote me on that and go oh my god, I

Rob Pickels  1:10:49

must be writing 6000 watts.

Trevor Connor  1:10:53

Finally, she brought up Rowan and I think the important thing that she pointed out and again, just going back to her love of vO two Max is most rowing events are 567 minutes in length. So rowing race is basically a vo two, Max. Yes. Anything else you want to point out about this review? Rob, I have one last thing. But anything you want to point out now

Rob Pickels  1:11:12

I think that we satisfied everything that I was interested in here, Trevor, while me with your last point. So

Trevor Connor  1:11:19

I love this. And remember, this is 1996 Robeson at all attempted to quantify training by the use of objective longitudinal training data, they showed that the mean intensity of steady state running for the participants in this study is considerably lower than the optimal training intensities suggested by some authors quoted above. So here’s my interpretation of that. This was the big realization that led to the whole idea of polarized training, which was we had been focusing in the research so much on interval work, we were really focused on high intensity working in those higher exercise domains. But the top endurance athletes had already discovered that spending most of their time and low intensity and just a little bit of time, at very high intensity is how they achieved the top levels. And what you kind of see here and sorry, bilum view here this and yell at me, I understand, is her kind of scratching her head at why are these runners going so slow? As because we really hadn’t. That whole concept really hadn’t come out in the literature yet. Sure. It was just so focused on intensity and intervals at the time. Interesting. Shall we wrap this one up, Rob?

Rob Pickels  1:12:35

Man, this was a great conversation. I really love talking about these researchers that have been formative, the funny stories, the interesting things, it’s always eye opening to not necessarily just look at what’s new, but to go back and reread, and I’m sure that I had read these studies, but I certainly forgot about them. In the meantime, it

Trevor Connor  1:12:56

gives such a context to what we read now. So for example, again, I was pointing out you see this huge focus in her research on vo two max velocity of vO two max. And you still see that really impacting the research now even though you have so many athletes and so many coaches that are training based on FTP, that you still see the importance of this historical context and how it’s helped to shape where we are now.

Rob Pickels  1:13:23

Well, this afternoon I am 100% doing some 3030s with a recovery at 50% of my high intensity workload. Just saying yeah,

Trevor Connor  1:13:32

well that has been another seminal episode. That was a lot of fun. That

Rob Pickels  1:13:36

That was another episode of Fast Talk. Subscribe toFast Talk wherever prefer to find your favorite podcast, be sure to leave us a rating and a review. The thoughts and opinions expressed on Fast Talk are those of the individual. And as always, we’d love your feedback to join the conversation at to discuss each and every episode. Become a member of Fast Talk Laboratories at To become a part of our education and coaching community. For Trevor Connor. I’m Rob Pickels. Thanks for listening!