By Chris Case
July 30, 2020

122 // Mission impossible: determining your true threshold

What is it that is nearly universally included in every piece of correspondence we receive? It’s some indication of a listener’s “threshold.” Often that figure is stated as if it is an absolute or as if it’s 100-percent accurate. And that’s what we want to address today: How accurate are these numbers, really? It turns out, not very. And as an extension of that, we also discuss just how difficult it is to get an accurate figure, for myriad reasons. We’ll discuss several of the most common ways to determine your threshold, and the advantages and disadvantages of each.  

Coincidentally, we were already planning to record this episode when Trevor received an unpublished review by a team out of Auckland, New Zealand, led by researcher Ed Maunder at the Sports Performance Research Institute of the Auckland University of Technology. The review is a fantastic summary of this very concept, but since it isn’t yet published, we can’t discuss the findings just yet. That said, the group had a lot of great points that helped shape this episode, thus we do need to give them full credit for those ideas in this show. 

Once the review is published, we’ll do a second episode in which we’ll interview the researchers and discuss their review. One of the fascinating concepts we look forward to discussing with them is how “durability” factors into threshold measurements. Stay tuned.   

Now, let’s make you fast! 


  • Baron, B., Noakes, T. D., Dekerle, J., Moullan, F., Robin, S., Matran, R., & Pelayo, P. (2008). Why does exercise terminate at the maximal lactate steady state intensity? British Journal of Sports Medicine, 42(10), 828. Retrieved from 
  • CHIDNOK, W., DIMENNA, F. J., BAILEY, S. J., WILKERSON, D. P., VANHATALO, A., & JONES, A. M. (2013). Effects of Pacing Strategy on Work Done above Critical Power during High-Intensity Exercise. Medicine & Science in Sports & Exercise, 45(7), 1377–1385. Retrieved from 
  • Jamnick, N. A., Botella, J., Pyne, D. B., & Bishop, D. J. (2018). Manipulating graded exercise test variables affects the validity of the lactate threshold and [Formula: see text]. PloS One, 13(7), e0199794. Retrieved from 
  • JOHNSON, T. M., SEXTON, P. J., PLACEK, A. M., MURRAY, S. R., & PETTITT, R. W. (2011). Reliability Analysis of the 3-min All-Out Exercise Test for Cycle Ergometry. Medicine & Science in Sports & Exercise, 43(12), 2375–2380. Retrieved from 
  • Jones, A. M., Burnley, M., Black, M. I., Poole, D. C., & Vanhatalo, A. (2019). The maximal metabolic steady state: redefining the “gold standard”. Physiological Reports, 7(10), e14098. Retrieved from 
  • Jones, A. M., & Vanhatalo, A. (2017). The ‘Critical Power’ Concept: Applications to Sports Performance with a Focus on Intermittent High-Intensity Exercise. Sports Medicine, 47(S1), 65–78. Retrieved from 
  • Karsten, B., Jobson, S. A., Hopker, J., Stevens, L., & Beedie, C. (2015). Validity and reliability of critical power field testing. European Journal of Applied Physiology, 115(1), 197–204. Retrieved from 
  • Karsten, B., Jobson, S., Hopker, J., Jimenez, A., & Beedie, C. (2013). High Agreement between Laboratory and Field Estimates of Critical Power in Cycling. International Journal of Sports Medicine, 35(04), 298–303. Retrieved from 
  • Maturana, F. M., Fontana, F. Y., Pogliaghi, S., Passfield, L., & Murias, J. M. (2018). Critical power: How different protocols and models affect its determination. Journal of Science and Medicine in Sport, 21(7), 742–747. Retrieved from 
  • Puchowicz, M. J., Mizelman, E., Yogev, A., Koehle, M. S., Townsend, N. E., & Clarke, D. C. (2018). The Critical Power Model as a Potential Tool for Anti-doping. Frontiers in Physiology, 9, 643. Retrieved from 
  • Shrier, I. (2008). Determination of Critical Power Using a 3-min All-out Cycling Test. Yearbook of Sports Medicine, 2008, 82–83. Retrieved from 
  • SKIBA, P. F., CHIDNOK, W., VANHATALO, A., & JONES, A. M. (2012). Modeling the Expenditure and Reconstitution of Work Capacity above Critical Power. Medicine & Science in Sports & Exercise, 44(8), 1526–1532. Retrieved from 
  • Smith, J. C. (n.d.). Critical Power is related to cycling time tiral performance. 
  • Townsend, N. E., Nichols, D. S., Skiba, P. F., Racinais, S., & Périard, J. D. (2017). Prediction of Critical Power and W′ in Hypoxia: Application to Work-Balance Modelling. Frontiers in Physiology, 8, 180. Retrieved from 
  • Vanhatalo, A., Jones, A. M., & Burnley, M. (2011). Application of Critical Power in Sport. International Journal of Sports Physiology and Performance, 6(1), 128–136. Retrieved from   


    (Please excuse any typos as this transcript is generated automatically through A.I.)

    Chris Case  0:12  

    Everyone, welcome to Fast Talk your source for the science of cycling performance. I am your host Chris Case. Today Coach Connor and I discuss something that comes up nearly every time we receive an email from one of our devoted listeners from you. By the way, please, please keep sending us questions, voice memos, we love them. We appreciate them. And they do so much for us when it comes to creating new episodes. But what is it that is nearly universally included in every piece of correspondence we receive? Well, it’s some indication of a listeners, quote unquote threshold. Often that figure is stated as if it is an absolute, as if it’s 100% accurate and that’s what we want to address today. How accurate are these numbers Really? Turns out, not very. And as an extension of that, we also discussed just how difficult it is to get an accurate figure for myriad reasons. We’ll discuss several of the most common ways to determine your threshold, and the advantages and disadvantages of each. Coincidentally, we were already planning to record this episode when Trevor received an unpublished review by a team out of Auckland, New Zealand, led by researcher Ed Maunder at the sports performance Research Institute of the Auckland University of Technology. The review is a fantastic summary of this very concept, but it isn’t published yet and therefore we can’t discuss the findings. That said the group had a lot of great points that helped shape this episode. Thus, we give them full credit for those ideas in the show. Once the review is published, we’ll do a second episode in which we’ll interview The researchers discuss their review. One of the most fascinating concepts we look forward to discussing with them is how this concept of durability factors into threshold measurements. Stay tuned for that discussion coming soon. Now, let’s make you fast. Trevor, I know you’ve been wearing a Whoop strap for years and it sounds like the 3.0 is much improved product.


    Trevor Connor  2:30  

    I am really impressed with the 3.0. Yeah, I used the 2.0 for a bit which was actually yours, but I lost it in airport. So I so I got the 3.0 and any niggling issues I have with the 2.0 have that worked out battery last longer. But what I’m really impressed by after I got it, I started downloading some workouts to compare it to a chest strap and I have now use multiple risk based heart rate monitors and this is the first one I personally seen where it is getting heart rate as good as a chest case, chest strap. So it is accurate the heart rate variability ever was about the 2.0. I got some wonky numbers. This just seems to give a more realistic, more accurate reading of my heart rate variability. They have worked out anything that I would think was a kink in the 2.0. sleep better, recover faster and train smarter. Optimize your performance with Whoop.


    we’ve been asked this a bunch of times actually wrote an article about it a while ago but this whole question of threshold which we just think is this really simple number easy to get at easy to determine what that no that I mean the the deeper you dive into the science, the deep you dive into this question, the more complicated it gets, and you realize the harder it is to actually determine this number. Or even just simply define it. So I’ve been looking forward to doing this episode, I was surprised to see that while I wrote an article about it, we actually hadn’t specifically done an episode about it. I also do need to give full credit here. While we were planning this episode, I actually coincidentally got an unpublished review from this team out of Auckland led by Ed Maunder addressing exactly this question, and it’s one of those things I can’t really unreal it. So I will give them full credit that they their review has influenced this show, but I’m not going to mention it through this episode it is unpublished, so just need to give them credit, but also show them the respect we don’t want to discuss a review until it is finished.


    Chris Case  5:08  

    Great. And yeah, we’ve spoken certainly about some of the things people will hear today, FDP, MLSS, we’ve defined some of these things, but we haven’t defined all of them. And we’ve never really dissected each in the way that we’re going to do today and try to get a sense for, you know, pros and cons of each why it’s so important to get this number, right how what implications it has for training, racing, declines in in some of the accuracy of metrics that you might rely quite heavily on. So all of that and more today.


    Trevor Connor  5:45  

    Yeah, I would say the theme for today. This is a visual that I for some reason, just came to my head that I kind of like is hitting threshold Figuring out your threshold number is kind of like trying to hit a bull’s eye on a dartboard from 100 feet away when that dartboard is moving. This is not an easy thing to do.


    Chris Case  6:14  

    Yeah, you might, you might actually hit the bullseye. But it’s very unlikely. Right for more than not, he might throw the dart and the Dart hits the wall instead of the dartboard.


    Trevor Connor  6:28  

    Right. And that’s really important, because I think there is a general belief that it is really easy to figure out your threshold power your FTP, or whatever you want to call it. And we’ll go into all this different terminology. That Yeah, no, I can figure that out. I’ve got this number on whatever software I’m using. That’s a pretty accurate number. And we know this because often we get emails from people asking us questions. And the first thing that goes, Well, my threshold powers this are my FTP is this. And whenever I read that, my response is always How do you know? Are you certain? And that’s what we’re going to get across in this episode, I hope, which is, Whoa, it’s actually really hard to get an accurate number and worse, as we’ll explain, you might get an accurate number on Tuesday. That doesn’t mean it’s going to be an accurate number on Wednesday. It’s that good old. You’ll hit the bull’s eye every once in a while, but it’s pretty rare.


    Chris Case  7:23  

    Yeah. And that’s, I think, really going to be interesting to talk about the how this shifts and what effects that has on so many other things, this cascade of issues that you might run into, and not not trying to be overly dramatic about it. But yeah, some people rely heavily on on this date, one data point to support a lot of other formulas and just good to know what impact that has.


    Trevor Connor  7:51  

    So shall we dive into this? 


    Chris Case  7:53  

    Let’s do it. Yeah. 

    What is threshold?

    Trevor Connor  7:55  

    So I guess since we never actually technically did an episode on this, but I wrote an article about I just want to start by saying when I wrote that article, I just had of interest when I’ve heard a bunch of different terms for describing your threshold. So I wanted to see how many are out there. And I came up with a list of over 30. And I’m actually looking at a study or a review right now discussing the topic and here’s just their shortlist. And they even say this isn’t comprehensive, sorry, starting in the middle of a sentence, but rest of it is on the next page, I’m just going to start in the middle of a sentence, or enable an accurate estimation of maximal metabolic steady state and include the lactate threshold gas exchange threshold Gt ventilatory threshold lactate turnpoint LTP anaerobic threshold, the onset of blood lactate accumulation, corresponding to an absolute blood lactate concentration, for millimoles, ob la individuel, anaerobic threshold lactate, minimum And respiratory compensation threshold. We’ve also talked a lot in the show about vt two and one of my favorites, I wrote a paper about this in college and increase in V over vo two without an increase in V over co2 and an increase in FBO to without a decrease in F e co2. Don’t ask me to explain that one. I wrote that paper A long time ago. That really is and you have to do gas exchange to get that one. It’s a tough one, but it’s actually pretty good. The important thing here is each one of those that I just read. It’s not just terminology. Each one comes with a different way of measuring and will produce a slightly different number. So this idea that there is one threshold here it is, it’s really easy to figure out is just not the case. And you’re gonna have different people That are going to stand behind different things I’ve said on the show many times that I really like the mlss, maximal lactate steady state. But this review that I just read from is actually a comparison of mlss. And what’s called critical power, which we’re gonna dive into those two in this episode. And actually, this review makes a very strong case for no mlss should not be the gold standard. Critical power should be.


    Chris Case  10:29  

    Is it worth defining, briefly, this term threshold then just as a construct, because you’re talking about how some people think it’s easy to determine my threshold, but we’re talking about 30, 40 different methods to determine quote unquote, your threshold. So what is briefly threshold? What are we trying to determine here,


    Trevor Connor  10:52  

    right, so I’ll give you the best that I can possibly give for a definition, but you’re getting at the key point here, which is, there isn’t even consensus and what’s the correct term? So your most common is probably just talking about your anaerobic threshold. But there are some researchers out there who when they hear that are gonna cringe because it’s not an anaerobic threshold. It’s actually a continuum. You’re still working aerobicly. So you can’t say that. We can’t even land on a here’s a set term. So you know, I just go with the cloak layer, which is everybody talks about threshold. And again, well, you have an anaerobic threshold, you also have an aerobic threshold, we’ve talked about vt one v2, so even that’s not accurate. So it’s really tough. Any term that you use any way that used to define it, there’s gonna be somebody who go well, no, that’s not quite right. So let’s just for the purpose of this episode, we’re talking about threshold. And we’ve talked about, there’s the two thresholds that that lower aerobic threshold that higher I’ll use the term anaerobic threshold. Today we’re just talking about the anaerobic threshold and if you go into the literature you’re gonna probably find 20 different ways of defining this though there is what seems to be, at least from what I’ve read a fairly consistent definition. This is certainly what I’ve subscribed to, which is this anaerobic threshold or whatever you want to call it is the highest intensity at which you can maintain metabolic sustainability. So let me explain what that means. And I’m sure there’s probably a little better word in that. But you have a variety of metabolic markers, lactate levels, your pH balance, a whole bunch of things you can look at, let’s just talk about lactate. Because that’s, that’s a simple one. when you are really low intensity, lactate is going to stay at baseline which is right around or just below one millimole per liter. As you increase intensity, you will hit a point where it will start to rise. So it might go up to two millimoles might go up to three millimoles. But even though it rises, if you stay at that intensity, it will level off. So you’ll go up to three millimoles, but then stay at that intensity and you’re going to stay right around three millimoles. So that is sustainable, higher, but sustainable. There is a certain point, and you look at some of the older literature. They thought it was four millimoles for everybody you had four millimoles lactate is no longer sustainable. It’s actually a huge amount of individual variability. But the point being, you hit a certain intensity where that will no longer level off, it will just keep arising. So there’s a bunch of marker or several markers that you can look at. But lactate threshold is that or sorry, anaerobic threshold is that point where you can no longer sustain levels where they’re just going to keep rising, it means that you’re going to reach fatigue very quickly.

    Critical Power (CP)

    Chris Case  14:08  

    Very good. Well, now, do we want to address some of these methods like critical power and mlss? and define them even further? 


    Trevor Connor  14:19  

    Yes. So let’s just quickly give the big broad overview, we’re going to talk about a couple ways of defining threshold one is critical power. We’re going to talk about maximum lactate steady state. We’re going to talk about increment, incremental exercise assessment, which is just your in lab testing. And we’re going to talk about FTP. So we’re going to talk a bit about the pros and cons of each. We’re mostly going to talk today about using them to define threshold, but some of these tests define more than that. So other variables that might get measured by some of these tests or your vo 2 max your economy, your both your thresholds and then determine your training zones. And also some of them will show your substrate utilization. So how much fat you’re using versus how much carbohydrate. So with that, as you said, Chris, do we want to dive into critical power?


    Chris Case  15:20  

    Yeah, let’s do that one first. Okay, CP, as you’ll hear it referred to CP.


    Trevor Connor  15:26  

    So, I admit, before I did my research for this, I’d always been a big fan of maximal lactate steady state, but there are some good arguments for why critical power may be a better metric to use. So let’s talk first about how its measured. Which gets a little complicated. It’s not an easy test. It requires a series actually of tests that lasts between three and 15 minutes, and is basically you do each of these tests. to failure 


    Chris Case  16:01  

    must be done in a laboratory? 


    Trevor Connor  16:03  

    Preferably you want it to be controlled so preferably in a laboratory But yeah, I mean short of that finding a good hill where you can go and throttle yourself could probably work and then sending in the data so we won’t we won’t dive into that but generally testing with with CP when you read about it in the literature, yeah, they’re doing it in a lab and they’re keeping it pretty controlled. Three minutes is the minimum because you are trying to achieve vo two max and the belief is below about two minutes it’s impossible that you vo two max. So let’s take a quick step back. Critical power the whole concepts been around for a long time. I’ll explain why in a second. There seems to been a lot of research that was conducted on it in the 80s. This is back when two bado was coming up with with his protocol Part of it was because he was trying to study this concept of critical power. And you can’t talk about critical power without talking about what prime. So let me explain both. And this is going to be difficult to do without visualizing this, it might be good to go to a web browser and bring up a picture of this. But anybody who’s using modern software, you’ll be familiar with the power duration curve, which is this curve that shows your peak power from one second all the way to the longest ride you’ve ever done. So I’ll show the best one second power, you’ve had the best to second power you’ve hit the best three second battery keeps going out all the way to five hours or whatever it happens to be.


    Chris Case  17:44  

    It’s usually kind of like an L shaped in that it’s high at the short end and in lower at the at the tail end. Right and it goes it drops down,


    Trevor Connor  17:55  

    right. So before you had all this sophisticated software that could track All of your peak powers. This is when they came up with this test for critical power, which is the idea of, let’s do a three minute test, let’s do a five, five or six minute test, let’s do a test of these varying lengths, all of which are to failure all of what you need to achieve vo to max. And that’s then going to create the shape of the curve. So that that higher end that as you said, it starts very high, and then it drops quite precipitously, and then levels out. All these tests are designed to find the shape of that, that point where it levels out. And I cannot pronounce this good with terms like this 


    Chris Case  18:42  



    Trevor Connor  18:43  

    asymptote. Thank you. 


    Chris Case  18:44  

    Yeah, that’s a tough one. 


    Trevor Connor  18:45  

    So that leveling out point or stretch of the curve is what we would consider critical power. So if you just think about this rationally, if you look at that curve, and at five minutes here, say 250 watts, but at 30 minutes, your 245 watts, it’s holding pretty level, that means you’re sustaining that power. And member critical power is all about what is sustainable. So, and that’s how you estimate your critical power. Now, this part gets a little hard to explain without seeing the visual. I think Chris is going to post a critical power graph on the website. So you might want to look at this or just do a Google search. Well, I explain this, but you now have this power duration curve, which we just described, you then draw this horizontal line through the leveling out of that curve that represents your critical power. Now, the question is, how do you determine what prime well there’s something in science called the area under the curve, so easiest way to explain This is if you look at this power duration curve with a critical power line cutting through the more level part. When you get into those short durations, those curves are going to diverge if you took a marquee or highlighter and filled in that area between the critical power line and the power duration curve, and then you measured the area of that highlighted space, that area under the curve. That’s your watt prime. And that’s why it’s called a capacity. It’s not a rate. You’re not seeing how quickly you’re producing anaerobic power. It’s basically saying here’s how much power you have above critical power. And again, well it’s often referred to as anaerobic capacity. It’s not critical power is closer to your threshold. threshold is below vo to max vo to max is your highest point of your highest rate of aerobic metabolism. So a lot of that what prime is still produced aerobicly. But the idea here is you have this critical power, which is sustainable. Here is the quantity, let’s say, power that you have above that sustainable power.


    Chris Case  21:23  

    And that’s, yeah, it’s not filling it, you’re not filling in the huge spike of your sprint power. It’s a rectangle that goes on the lower edge from your critical power line up to but stays beneath that. The spike of your your power duration curve. Right,


    Trevor Connor  21:46  

    right. So again, I don’t want to get too scientific. I’m trying to describe this this graph, but just think of it as the volume between critical that critical power line And your power duration curve. That is your your watt prime. So the more you have there, the more anaerobic capacity you have, the closer those two lines are, the less anaerobic capacity I have. So a time trial or who would have a big critical power and not a big sprint or short duration power, they’re gonna have a small watt prime, a sprinter, who’s going to have a lower critical power, but have quite a high short duration power, they’re going to have a large watt prime. And the idea is when you do this test, each duration so from the three minute to the 15 minute, again, you you need to go to failure. And the belief is you hit failure simultaneously at the point that you hit both vo two Max and you completely deplete your watt prime Um, so like, completely lost you.


    Chris Case  23:04  

    It does make sense. You know, I pulled up a browser and took a look at what you were trying to describe. We’ll put an example of this power duration curve with white prime in its definition on our website. So check that out. So as you were describing it, I could, you know, I understand the struggle to describe it. It’s difficult, but it all makes sense. It does.


    Trevor Connor  23:27  

    So I have to admit that I’ve been critical of this concept, because a it is highly theoretical. And also what prime everybody says, well, it’s anaerobic capacity, but it’s not because you’re generating a lot of that power, still aerobically, it’s just how much power you can generate above critical power, which is both anaerobic and aerobic. So I’d always had my issues with it, but at the end of the day, critical power is getting at that definition. We just gave Have an array of anaerobic threshold, which is the highest sustainable level. And you are using just simple power tests. Simple Yes, hard. Yes. But you’re using a series of power tests to figure out what is your highest sustainable level. Obviously, one of the issues here is doing all those tests is really, really hard. Particularly if you’re trying to train because you need to do each one fresh. There’s five tests. So you pretty much have to take a week, week and a half off training in order to do this. So they have come up with a single three minute test. Just for practical reasons. That seems to be fairly decent. There’s been a series of reviews of it and it it’s pretty close to doing the full five tassets some, some studies have said not not quite there.


    Chris Case  24:55  

    Oh, people are always looking for that shortcut, aren’t they? Yes. Sometimes Sometimes if you want accurate numbers, you just got to put in the work and carve out some time to do something like this,


    Trevor Connor  25:07  

    Agreed, you know, but there’s always that balance of you got to get decent numbers, but you also have to keep training. You remember we have, we had Steve Neal on the show a couple episodes ago, and he uses his three minute test. And I would say for practical purposes, it’s quite often good enough. 


    Chris Case  25:25  

    Did he refer to this as his map? test? map? 


    Trevor Connor  25:29  

    Yes, basically, well, map test. So map when you ever hear somebody use map, I mean, they go Aha, you’re Canadian, because that’s a term that we use a lot out there. A map test is just a way of getting at what what in the US they’d refer to as vo two max power. So max map stands for maximum aerobic power, which is just a pretty much a synonym for vo two max. 


    Chris Case  25:56  

    All right. 


    Trevor Connor  25:57  

    The one nice thing about this is not only does it Give you an estimate of your anaerobic threshold, but you also determine this watt prime this how much you can how much power you you can put out above your threshold. And that can be very informative when generating intervals because sometimes you want to do interval work where you completely deplete that lot prime. And you can design fairly good interval work where you can ensure that both watt prime is depleted. And then make sure the recovery is long enough that you can repeat what prime well


    Chris Case  26:36  

    well left to do some critical power testing at some point, Trevor and compare. Sure that


    Trevor Connor  26:42  

    Sure that sounds like a lot of fun.


    Chris Case  26:45  

    I’m assuming that my watt prime is going to be bigger than your watt prime just based on our phenotypes as riders.


    Trevor Connor  26:55  

    Yeah, I’m going to assume that if you looked at my graph, there, there is no watt prime, just Nothing.


    Chris Case  27:02  

    You might call it a sliver. It’s not a rectangle. It’s just a little tiny little sliver of gray. In between a curve and a dotted line.


    Trevor Connor  27:12  

    You’re gonna get some poor scientists in a lab grown cotton like just can’t measure it.


    Unknown Speaker  27:18  

    Was that your?


    Trevor Connor  27:19  

    It’s too small? Yeah, that’s my horrible Scotty I can’t do that. Again, even do a Canadian.


    Unknown Speaker  27:25  

    That’s very true. That’s very true. You are a man without a country or an accent at this point.

    Maximal Lactate Steady State (MSLL)

    Trevor Connor  27:31  

    Okay, well, let’s move on. Shall we talk about maximal lactate steady state. We should, we should. So you’ve heard me talk about this before and I’m a big fan of maximal lactate steady state and after reading that my this review that came out in 2019, that compared critical power to mlss. I’m going to adjust my opinion a little. 


    Chris Case  27:57  

    No man, 


    Trevor Connor  27:58  

    which is Think, as a theoretical concept, I still like maximal lactate steady state the best because it’s based purely on physiology. But I would say the practical application has serious issues, or has issues to make it difficult to truly determine mlss. So, based on that this, this 2019 Review made a good case of, we really probably should be using critical power.


    Chris Case  28:34  

    Well tell us why tell us more about this well,


    Trevor Connor  28:36  

    so again, let’s start by talking about how this is measured. And if you thought the critical power test sounded miserable, let’s talk about the maximal lactate steady state test.


    Chris Case  28:48  

    Maybe this is why you liked it too, because I know you’re a masochist.


    Trevor Connor  28:52  

    Oh, it is miserable. It is absolutely miserable. So now one good argument was made that It is somewhat arbitrary how the protocol was determined. It has adjusted over time, but where it has landed, is you need to do a 30 minute test and your maximal lactate steady state. So again, it’s you we want to see things leveling off, we want to see you hit a steady state as the name implies. So what they want to see is from the 10 minute point, to the 30 minute point of that test, we should not see your blood lactate rise more than one millimole per liter. So in other words, it’s steady. Sure. Here’s a question you’re asking of, well, how do you pick a power to do that 30 minute test that to figure that out? The answer is you do it a bunch of times. Yeah, you have to do a series of 30 minute tests. Each one fresh again. This is gonna have a big impact on your training. And you just keep going up until you do one test at one wattage, and you meet those criteria. And then you do a another test at a higher wattage and you no longer meet that criteria. So let’s say you do a test, I’m actually looking at a graph right now, which shows his athlete doing the test at 270 watts. And they met the criteria they leveled out. So between 10 and 30 minutes, they stayed within one millimole. Then they did the test at 280 and lactates kept going up. Hmm. So the way the protocol works is, you then say it’s 270 because you pick the last one that you accomplished. This is actually quite I, I would say a little bit at least a little bit unusual because it’s only 10 watt increments. Sometimes you’ll see athletes do higher like sometimes it’ll be 20 watt increases, or 30 watt increases, probably not 30 watt, but 15, 20 watt, you’ll see, the issue is you take the lower one. So let’s say you did want it to 70, you met the criteria, you did another one at 290, you did not meet the criteria. It could be your actual maximum lactate steady state is to 85. Right? But that doesn’t matter. You’re gonna take the 270. So by definition, mlss will always underestimate. Always because


    Chris Case  31:31  

    Unless Unless you did a third test and tried it at 280. And then you would you could, I suppose you could keep doing tests to refine this number. Correct, right,


    Trevor Connor  31:41  

    which would be absolutely miserable, but you could potentially do that. And let’s also go back to what we said at the beginning of this episode, which is you fluctuate day to day. So again, it’s like trying to hit a moving dartboard. And so you kind of go well, we’re close enough. Yeah, 270 Plus or so this is where you get into that plus or minus 5% or five watts. Mm hmm. So that is one issue is that it will always underestimate. Always, always, always because you always take the lower value. One of the criticisms of critical power is that it tends to estimate your threshold about 5% higher than mlss. But if mlss always underestimates, that’s actually an argument for critical power. Sure. So that is one issue. Now let’s we’re not going to dive deep into this. But taking lactates is tough. Some researchers, you know, Jared, who we’ve talked with many times, he’s really good at it. And he has the right equipment, but you’re going to go to a lot of labs where they don’t, where the researcher isn’t very good. I still remember a friend asking me to help him with his lactate test at his Coach wanted him to do. His coach mailed the equipment for us to use. And I’m sitting there going, Yeah, we’re not doing this in the lab, how he I don’t have a lactate analyzer here. How do you expect me to do all this? Well, he mailed all this stuff. He had a single finger pricker is a little thing that punches a hole in the tip of your finger so you can get the blood. Yep. So he wanted me to just keep reusing it. Which just gets into all sorts of pollution and corruption issues. Yeah, uh, and then I was to put a couple drops of blood into separate vials. Then not refrigerate them and mail them back to him. There were so many issues in this, you know, and he sent me the results later. It’s like, what’s your interpretation of this made his email back very nice. My interpretation was, this was a waste of time.


    Chris Case  34:03  

    There wasn’t really anything done correctly in that incident, right?


    Trevor Connor  34:06  

    So you laugh at this, but there are a lot of you can go and get tests where it’s that bad. So when you’re talking about one millimole, increase over 10 to 30 minutes, from the 10 minute point to the 30 minute point. There’s a lot that can go wrong. There’s a lot of measurement error that can cause you to misinterpret or get bad results. So again, in concept, I love maximal lactate steady state. But the practical side of having to do a whole bunch of 30 minute hard tests of getting accurate lactates of the fact that you are always going to underestimate when you get into the application. It’s got issues


    Chris Case  34:58  

    Yeah, and Not to mention the fact that this has to be done in a lab to be able to frequently test someone’s lactate while they’re right while they continue to ride.


    Trevor Connor  35:12  

    Exactly. So it’s not an easy test to do at home. Actually, it’s not a possible test to do at home. So, yeah, I mean, both critical power and maximal lactate steady state testing suffer from, it’s not something you can do on your own. You generally need a lab or you need somebody there to test you, particularly with mlss. You have to sacrifice a fair amount of training, and you have to do a whole series of really tough testing. By the way, one other issue with mlss if you’re doing a whole series of 30 minute time trials to try to find it. If you have somebody who’s less trained, those tests are going to train them. So as you’re continuing to refine this their their MLS has might actually be changing.


    Chris Case  36:04  

    Yeah, there you go. That’s an interesting point. I hadn’t thought about that. But yeah, that’s that’s very true.


    Trevor Connor  36:10  

    Yep. So let’s move on to what’s next.

    Physiological testing/ incremental exercise (step) testing

    Chris Case  36:19  

    Yeah, so incremental exercise test. We really did dive pretty deep into physiological testing in Episode 89. You mentioned Jared Berg, former lead physiologist at the University of Colorado Sports Medicine and Performance Center. So refer back to that episode for a lot more detail here. But this is sort of what we generally refer to as physiological testing. But that is a pretty vague term.


    Trevor Connor  36:51  

    Right? And I would say if we’re gonna actually not spend a lot of time on this because we did do a whole episode on it and unlike mlss and CPP where there’s a fairly standardized protocol. There are probably 100 different protocols for the step tests. So really hard to in five minutes try to explain them all. Even to the point we talked about the fact that there’s two major types, there’s your vo two max tests where you’re, you’re increasing wattage fairly regularly. And then there’s the lactate step test, where you are having stages that are much longer. So the shortest I’ve seen is three minutes. The longest I’ve seen is dr saw Milan’s protocol which is 10 minutes stages, which takes a really long time to do. So. Standard might be what you typically see as a five minute stage with maybe 25 watt increases. You might start at 100 watts, do that for five minutes and you go up to 125. Do that for five minutes, etc, etc, etc. Until you can’t go anymore. And each stage, you’re taking lactates, what you end up with is a lactate curve that at these lower intensities, you’re going to see a very level lactate. And at a certain point, it starts to kick up, and then it starts to go up quite quickly. So, again, I’m giving the really quick summary listen to that episode if you want to learn a lot more about this. But the idea here is that point where it starts to go up corresponds with your lower threshold that we talked about is your aerobic threshold. And then there is a point higher up that indicates your anaerobic threshold and there are a whole bunch of ways of figuring out What that point is, so one of the simplest is to just say when you hit four millimoles, blood lactate, you’ve hit your anaerobic threshold. problem is there’s a huge amount of individual variability there. They have a whole bunch of different ways of looking at this graph and figuring out where does that threshold lie. One is you’re looking for the the deepest point in that curve. There’s another method called the d max method, which you just need a bunch of rulers and interesting tools. All right, I don’t want to fill in a pickaxe. I was about to describe this. I’m like, wait a minute, I couldn’t even describe the CP curve. I’m not gonna try to describe this without a visual.


    Chris Case  39:45  

    I think it’s fair to say that that with this test, there’s a fair amount that goes into the interpretation of the tests. And there’s different methods to do that. There’s also as we spoke about in Episode 89 with with Jared Done literally hundreds, if not thousands of these tests, there’s some art to knowing how to interpret it.


    Trevor Connor  40:08  

    Right? So the short version of this is all those issues that we talked about with collecting lactates collecting accurate lactates when we were talking about mlss apply here as well. So it’s quite possible to get pretty bad lactates it’s quite, you know, they’re they’re really good lactate analyzers, there’s not so good lactate analyzers. So that’s a whole issue. Now, let’s put that aside and just say, yes, somehow, we had an amazing test, all the right equipment was used, and we got incredibly accurate lactates. And we now had this curve that we just talked about. There was a study done by Yam Nick, that then took these different methods for analyzing or figuring out where the anaerobic threshold was, and they found depending on which method you used, So again, one single curve, one single test, they found the anaerobic threshold can be anywhere from 243 watts to 338.


    Chris Case  41:10  

    That’s a huge range. Huge.


    Trevor Connor  41:13  

    So you need somebody who’s really good at looking at these graphs and figuring out where your threshold is at. Jared was was excellent at this, in my opinion. But there’s a lot of people out there who will look at this curve and go, Oh, well, you’re 250 in other person looking to go well, you’re 310. That’s a big difference.


    Chris Case  41:35  

    Yes, so much so that, yeah, that that’s just massive and can really run you astray if you’re not having it done by a really experienced reputable source,


    Trevor Connor  41:50  

    right. Now, the one benefit to this test also we talked about, those are some of the disadvantages. The other disadvantage is you need to find a lab you have to go somewhere where they have all this gear. The one advantage of this testing method over all the others is we talked to the beginning about all the different variables that you can measure. So vo to max economy, substrate utilization, both thresholds. This is the one test that can give you if you as long as you use gas exchange, which means you wear a mask and it measures gas exchange. It is the one test that can give you all that information.


    Chris Case  42:28  

    Yeah, in that way. It’s robust. Obviously, you know, we’re trying to give an overview of these different tests. We’ve both been tested several times at the Performance Center, and you can be certain that the data you’re getting there and the interpretation you’re getting there is top notch and you’re getting all of these other components tested at the same time. So it’s a great way It’s a great tool. Yes, totally, it’s totally worth it. But caution being, not every facility, not every lab is as good as the Performance Center. So shop wisely when you’re looking for this,


    Trevor Connor  43:13  

    right. And even then you’re talking about looking for a good Performance Center. For a lot of people, it’s an issue of finding a Performance Center at all. I have an athlete in Washington, DC, this is a major city. This is a big city. There’s nobody in Washington DC, who does this, at least not that he could find,


    Chris Case  43:33  

    again, refer back to Episode 89, where we actually go much deeper into all the different components here, what you’re what gas exchange is, what that data tells you and so forth. Do we want to move on to one that I can almost guarantee every listener has heard of FTP?

    Functional Threshold Power (FTP)

    Trevor Connor  43:53  

    Absolutely. Let’s talk about FTP. This is a as you said, because everybody’s heard of it. This is a term that gets thrown around a lot. And I think it runs that risk, because it’s thrown around so much. People don’t really, or a lot of people don’t really understand what it means.


    Chris Case  44:13  

    If somebody had the trademark on FTP, they’d run the risk of having it be generic at this point. So what you’re saying?


    Trevor Connor  44:20  

    Yeah, and actually, I do think I think it is trademarked, isn’t it? Oh, maybe Dr. Coggan andHunter Allen are training peaks on the the trademark in this


    Chris Case  44:31  

    pop. You’re probably right. Actually, I didn’t even think of it like that. But yeah, they probably do. But it gets thrown around by so many people in so many circumstances, for so many different reasons. And I’m I you know, again, it’s popular for what, for certain reasons, and we’ll talk about that, but it’s also completely misunderstood. In a lot of ways, yes. For those for those same reasons.


    Trevor Connor  45:00  

    But let’s give our credit. This is a concept that was developed by Dr. Coggan and Hunter Allen A long time ago. And it had a real good purpose to it, which is what we were talking about. All these other methods generally require a lab are really hard to do. And for most people are just not practical or possible. So they needed some sort of out on the road test ability to come up with this number. And that was the origins of FTP. First of all really important thing to understand about it is it’s sort of physiological, but it’s really not is the way I think of it. It’s it’s based on a physiological concept that when we were talking about sustainability, remember I said sustainability always has a time component. So nothing is sustainable if you go long enough. So the Generally what you see is that critical power mlss. The the belief is there, those wattages are sustainable for about an hour. Now this has been put to the test. And it actually widely varies anywhere from read some studies where they found that mlss was sustainable or critical power sustainable for only 20 minutes. I’ve seen some that found 40 minutes some that go Yeah, this was sustainable for an hour. But in theory, your anaerobic threshold power is sustainable for about an hour. So hence FTP. To determine your true FTP requires an hour test. Gotta go as hard as you can for an hour. That doesn’t address how are you generating that power? Are you somebody that just has this amazing ability to go above threshold? Are you somebody who actually doesn’t have the ability to hurt very much That’s important because let’s say you’re not a very good time traveler, you don’t have the ability to hurt very much. You might go out your threshold true threshold that the highest sustainable power might be, say 250 watts, but you’re just not good and an hour time travel. So you might do 225 that’s gonna underestimate. So that’s why I say it’s sort of physiological, but it’s really not. Does that make sense?


    Chris Case  47:30  

    Yeah, it does. Absolutely. Yeah.


    Trevor Connor  47:32  

    So that’s, that’s my bias. The other thing is doing an hour test. It’s tough though. We had Dr. Siler come on the show and said, Look, I did an hour test right before this show. I think there was this second episode we had him on.


    Chris Case  47:47  

    Yeah, it was while ago, but I think he actually does this more often than every time he comes on our show. So you can, you know, 2,3, 4 times a year, I don’t know but he likes it. He’s a glutton for punishment.


    Trevor Connor  48:02  

    Here you have a test where, because of ability to perform this test, even just doing an hour test may or may not hit that true physiological threshold for you. Most people don’t like to do the hour test. So what’s becoming really popularized is the 20 minute test. And this again, Dr. Coggan and Hunter Allen put this in their original book popularized this concept of do a 20 minute test and then multiply it by 95%.


    Chris Case  48:35  

    This gets back to my comment about people people do like shortcuts, you know, you spoke about the the critical power test and it’s a series three minutes, six minutes up to up to 15 minutes, but there is now this quote unquote, substitute where you can just do the three minute and then run it through a formula and get your critical power number. This is the equivalent here and yeah, this is this is very popular. I would, I would take a gas that most people that throw around their FTP number haven’t done an hour test, they’ve probably done some 20 minutes or a series of tests where they take that 20 minute at the end of like we’ve spoken about before. Neil Henderson’s protocol, something like that. We recently spoke about that with Steve Neal, on Question and Answer episode. And they estimate this based on a shortened version of the hour.


    Trevor Connor  49:40  

    Right. So this is where we’re getting into fuzziness where you can end up with a number that doesn’t serve you because there’s already issues with the one hour now you’re doing a 20 minute test when you’re doing a 20 minute test. This is Where if you have that big anaerobic capacity, you can kind of physiologically cheat. We’re trying to get at what is your highest sustainable mostly aerobic effort. But if you bring in a whole lot of anaerobic metabolism, you can get a little higher than that. And I see that with some athletes. Other issues with this is they have started doing tests to say how accurate is this 20 minute test multiplied by 95%. And what they have found is that it tends to overestimate mlss by five to 7%. So they said let’s compare this FTP 20 minute test to both of those, and they found it overestimated mlss by about five to 7%. Now if you remember CP tends to be about 5% higher than mlss. So they also compared it to CP and found that what It averaged out to being basically the same, there was poor agreement. So from athlete to athlete, you just didn’t get them matching up always very well. So not the best metric always. And one study that I read basically said, better to multiple to get a true estimate of your 60 minute power, you really need to multiply your 20 minute power by by by about 90%. But huge athlete variants as well and particularly a higher level the athletes The closer to that 95% you get. So it’s a real rough estimate. And fortunately, I see a lot of athletes that go and do the 20 minute test go Alright, I love that number and they just plug that number into their FTP and then they’re really dramatically overestimating their FTP power.


    Chris Case  51:54  

    This does bring bring a very big question to my mind playing devil’s advocate here. We’ve walked through each of these tests, and we’ve been critical of each of these tests, none is perfect. Some are easier to perform than others, some take a lab to perform, and that might be out of the Range or out of possibility for a lot of people. But you, you do need something. So what is the harm in some of these estimates? And I know that’s a big question.


    Trevor Connor  52:29  

    There’s nothing as long as you understand that this is not when you get that number, that FTP that you see in your software, it is not gold. It is not a this is absolutely it. You know, the thing I was going to finish up with saying for FTP is that basically, it’s not a great correlate to your anaerobic threshold. But doing regular FTP tests is very good at showing improvements in your performance over time. So if you keep doing those 20 minute tests, it could be 2030 watts off of your actual true physiological anaerobic threshold. But over the course of the season, that number goes up 3040 watts, you’re stronger that that you can tell you can rely on. So that’s one of the benefits is you can see your improvements over time.


    Chris Case  53:35  

    This episode of fast Talk is brought to you by whoop.


    Trevor Connor  53:38  

    Whoop is offering 50% off at the code fast talk. That’s f a s t ta l k at checkout. Go to whoop. That’s w h o o And enter fast talk at checkout to save 15% sleep better, recover faster and train smarter. Optimize your performance with Whoop

    Other threshold models and the importance of feeling your way to better training

    Chris Case  54:03  

    Trevor, I know that the you know, there are some software out there that likes to estimate your threshold power. What? What do you think of those? What’s their value? And what are some of the shortcomings?


    Trevor Connor  54:17  

    Again, I think there is some value to this, interestingly, at least with training peaks and Wk Oh, so they call it their mfdp, which is this estimated FTP. I actually find it kind of funny that they use FTP because their method is much closer to critical power than actual FTP. So it’s not based on seeing what’s the best one hour power you’ve done in the last 42 days or 90 day whatever time period you’re using, they actually use that power duration curve. So all good software now can show your power duration curve, which we were talking about before, which is that peak, one second power, all the way Up to peak five hour power. These estimates that you see in the software does exactly what CP does, which is look for that. I’ve already forgotten how to pronounce that word. What’s the word again, Chris, 


    Chris Case  55:11  

    the asymtope. 


    Trevor Connor  55:12  

    Thank you, it looks for that, that point that leveling in the curve, and then draws that line through it and says that is your estimated threshold power. So it’s actually not too bad. It can be a really good guide, there’s just a couple things to be aware of is one in the software, your power duration curve is based on the best one second power you you have hit in that. So you always give a time period for this estimated FTP and by default in Wk o and training peaks is 42 days. So it is using your best one second, in the last 42 days. It’s using your best five minutes in the last 42 days. It’s taken all your best. So you might have had a race that was absolutely banner performance. That’s what’s being used. So be a little bit concerned about that. And actually, Tim did address that in the show and said they’ve made this a little more sophisticated where they avoid having this incredible day, really throw off your numbers. So that’s, that’s getting a little bit better. But also remember that if they just did the straight curve of the best one second best two second best, three second, and so forth, it’s actually not a very smooth looking curve, it can be all over the map. So they have to do a lot of smoothing of that curve. And when you smooth that’s going to affect to actually affect quite dramatically the shape of the curve. So to give you an example, I have an athlete I’m working with right now he’s not doing any racing because nobody’s racing right now. We’ve been doing a ton of threshold work as he’s decided that he wants to try and do a PR and a time trial course that’s something you can do by himself. So we were getting his estimated FTP up really high. But finally hit a point where I said we’re just doing nothing but threshold work you’re turning into just this tank with no top end so I said I want you to go out and do some sprint work. So he did a little bit of sprint work went out, did a couple Sprint’s It was the first time and months he broke, probably 500 watts. So that suddenly changed quite dramatically the shape of his curve. And in that one day, his estimated FTP dropped 30 watts.


    Chris Case  57:37  

    Hmm, interesting. Yep.


    Trevor Connor  57:40  

    So you got to take if you’re going to use that you got to take some responsibility to keep that curve accurately means you still have to go out and do a bunch of tests. Make sure you’re hitting some top end power, make sure you’re doing some good, longer range power to make sure the shape of that curve actually at accurately represents you.


    Chris Case  58:02  

    If you go to a race like the tour the healer, and on the you know, the first two stages are pretty big, pretty big days. And you might go into that race thinking, Oh, my FTP is 300 watts, you do find in the first day you do find them the second day, but they’re, you know, they’re big days. And then it comes to the critical time trial. And if you’re a writer that relies on that FTP number to understand your pacing for the time trial, you’re having to Well, some people, not knowing that it erodes or changes from the date from day to day might stick with that 300 FTP number. To to, to help with their pacing. But more than likely, if you’re an amateur writer, that FTP is going to be could be considerably lower on time trials. So you would want to revise your pacing strategy based on a different number. Is that what I’m hearing here? Is that correct?


    Trevor Connor  59:06  

    Well, that’s exactly it. And this is why I said at the beginning, trying to come up with this number is like trying to hit a dartboard from 100 feet away, and the dartboard is moving. This is the moving part of the dartboard your threshold. One day might be, say, 250 watts, the next day, it’s 240. The next day, it’s 260. And if you’re doing a stage race, it’s probably mostly just going down. But it’s going to change day to day today. And this is why you have to be we have been saying this throughout the show, particularly lately, and this is why we’re using this as a summary episode. We’re trying to find all these sophisticated metrics, but at the end of the day, the best cyclists use feel and this is part of it. Feel is taking responsibility for yourself instead of just relying on some number that A is really hard to figure out. And B is constantly changing. So if you just rely on that number and go, Well, my threshold is x. Therefore I’m going to time trial at that. I see athletes be unsuccessful doing that more than I see them being successful. were the best go out. They say, Okay, my thresholds typically 320. I’m going to target around there, see how I feel. And they might find out 10 minutes in or five minutes in am kind of tired today. So I’m going to bring it down, I’m going to go lower. Or they may go I’m feeling amazing. today. I’m going to bring it up. You have to trust that feel. One last thing I just want to bring up that review that compared CP to two mlss brought up this the importance of this fuzziness. And so I’m just going to read you one little bit out of it. Let me just quickly find it or find the starting points or not starting mid sentence again. There is therefore bandwidth are a gray area surrounding the model CPE estimate the size of which can be minimized to approximately plus or minus three to 5% with careful attention to the protocol. So notice they said if you do this right, you can have a three to 5% variance, for example, for a CT estimate of 300 watts and a standard error of 2%. So, on the low side, the real CP will lie between 294 and 306 watts. This means, however, that if this particular subject is exercised at exactly 300 watts, there is a 50% chance that he or she would be below CP and in the heavy intensity domain and a 50% chance that he or she would be above CP and in the severe intensity domain. This would have important implications for physiological responses, the nature and dynamics of fatigue development and exercise tolerance. This is what we’re up against, it’s really hard to come up with an accurate number. If you do come up with an accurate number. It’s kind of fuzzy, it varies day to day. And when you go out to do your interval work, if you just rely on that number, it could be one day, you’re training a little too easy. And another day, you’re training too hard. This is why when we have people say, Well, you know, five watts below my threshold, is that changing things we go? If somehow you actually knew your exact threshold and your 510 watts below it, yes, we can make statements about that. But we have no idea if you actually were 510 watts below on that regular day.


    Chris Case  1:02:38  

    Right? Yeah, we don’t know the accuracy of the test itself. We don’t know how that corresponds with your number on the day. We don’t know a lot of things we would need to answer that question and it in and again, it comes right back to your suggestion that when you’re riding, Racing training or otherwise, you do have to rely more on just a number. There’s more to it than that you have to use your brain you have to use the feelings that you have to assess, go through the checklist and take stock of all of the things that are coming at you numbers, feeling heart rate, power numbers, etc. to to figure out Yeah, this is this feels good right now or this is too hard or this is not hard enough. And you know, feeling isn’t 100% accurate either. But it helps add to the, the the tools, if you will to make more accurate assessments.


    Trevor Connor  1:03:51  

    The best athletes, the ones who’ve been training a long time and have been very successful, they they go out they often go out to do They’re training with a number in mind. But as soon as they get out there, they listen to the feel. And then they adjust. So we had Sep coos talk about that in the show that he’ll go out with a target power range. He taught he trains by power, he’ll do one interval and then go, Okay, how do I feel today, and then he adjusts his numbers. And that’s what we’re getting at is this number is really hazy. So it’s a guide, but you have to take responsibility.


    Chris Case  1:04:32  

    And hopefully, you go out and you have a number in mind and you ride at that. That number and you actually feel like it’s spot on and you do that, but, you know, every once in a while you have to adjust. But the hope is that if you’ve done everything correctly, and you’ve taken stock of all these things you use you get to know yourself as an athlete, you set those numbers. You set the objective for the day at the number that’s appropriate. it in, in that works out on the road, it feels feels like that’s right where you should be, but it’s not always the case. As Jim as Jim Miller, I think it was Jim Miller said in a recent episode, you know, some days you go out and you just don’t feel very good. But you get past that, for the next, the next training ride you you do things differently and you feel differently and you assess that ride as a, you know, as its own thing and try to forget the bad day that you have, because you’re inevitably going to have the bad days even though even world champions have bad days.


    Trevor Connor  1:05:39  

    Right? And then you get into the whole art form of of, sometimes you go out and just go Yeah, today, my anaerobic thresholds a little lower a couple days ago, it was 290. Today, it’s 275. So you’re just differentiating that from, I’m cooked. I shouldn’t be trying to do anything. Today, I’m going to turn around go home.


    Chris Case  1:06:03  

    Yep. Perhaps we’ve already said this in so many ways. But going back to my my big question about what’s, what’s the harm here and using these estimates? Well, we talked about this in the past, I think it’s worth reiterating. And that is that the numbers that we’re speaking about here today are often used to plug into other formulas that have been created that have become popular, and that people are starting to rely heavily on to help them design their training. So if the threshold power number that you plug into these formulas, it’s an estimate. But if it’s a bad estimate, then you’re going to put bad data into a formula and you’re going to consequently get bad data out of that formula and then that runs the risk. of throwing your training off completely. Right. Are there any What of it? What do I have that right, Trevor? And what are some other problems? Is that is that the big one?


    Trevor Connor  1:07:10  

    No, I think you are spot on is that if you’re using a number, that’s an estimate that varies as the basis for everything else, and everything’s built on top of that, you get more and more error as you move up. So you have to look at all this stuff. Look at I use Wk o analyze my athletes constantly. But you always have to do with a grain of salt and not believe that this is so specific and accurate, as a lot of people want to believe it is and that’s, you know, Tim came on the show. He’s the guy creating the software saying, No, you can’t see this as gospel. It is a guide it helps but it’s not perfect and nor can it ever be perfect because of how hard it is to come up with these numbers. And how much of these numbers fluctuate you know, I’ll give you an example. We are Talking with Tim about TSS. I went yesterday and did a six and a half hour ride with 12,000 feet of climbing. I started with a hard climb I finished with a hard climb. According to my TSS, the hard climb that I started with generated more training stress, I can tell you from feel I was killing myself on that final climb, I was not killing myself on that first climb because that durability, I was tired by the end of this ride, my numbers had all declined, but TSS doesn’t factor that in, it treats you like you’re fresh throughout. So according to it, that second climb, or that final climb, just didn’t generate as much training stress. So that’s where one of the places people can get themselves in trouble is not factoring that in thinking every TSS number that you generate is equal, which is not the case and that’s where you can start overtraining.

    Final Thoughts on Threshold Testing

    Chris Case  1:08:58  

    So another big Question for you, Trevor, we’ve pointed out again, generally speaking, we’ve pointed out four or five different methods here, and all of them have their flaws. But people need this number two to help guide zones and in training and so forth. So what do you suggest here? Is it a matter of testing not too frequently, but frequently enough that you can fine tune these numbers over time is it you know, if you have access to a reputable lab, getting in there and getting tested to get some baseline data and then and then use that number to say you get a CP number or an MLS NUMBER or a threshold number from an incremental step test in a lab? Do you use that to guide your FTP testing in the future to sort of check it to make sure it all works out correctly. What? No long winded way of saying? How can people best find their threshold without making mistakes or having it be so rough of an estimate that it hurts them and rather than helps them?


    Trevor Connor  1:10:19  

    I’m gonna go with thee. I think any of these are fine. As long as you recognize that again, this is not dogma, that number can be a little bit off. There’s still value to doing them, you know, even the FTP test the 20 minute test, not highly accurate, but it can show improvements over time. So as long as you get that number and take it with a grain of salt, I think it can be incredibly valuable but to show your progress and to guide your training. I think as I said before, I think you need to learn feel But the number of particularly for a very novice, cyclists can be very helpful. So I’ve worked with athletes who are brand new, I tell them to go out and do threshold intervals. And let’s say they’re their true threshold was 250. They go on throttle themselves at 400 watts and don’t complete the intervals because they have no sense of field. So for those athletes, let’s go do a test, we might come up with 240 watts or 260 watts as opposed to their actual 250 say, so it’s not quite accurate, but it’s still better having them go out and attempted at 260 watts, then their gut impulse of I’m going to start a 400 watts and blow up at least give some guidance, but you need to learn that feel over time. And what you see in the best athletes is, let’s say again, their their actual threshold is 300. They measure it at three 20 they’re really good athletes are going to go out and do intervals and go Yeah, 328 right. They’ll they’ll use it as starting point, but they’ll do their intervals at the 300. My personal bias is the numbers of guide it’ll help you it’ll show progress. You can get other information as well, such as substrate utilization, etc. But at the end of the day, know that that number is a ballpark and it’s feel that’s going to give you the rest of the way. That was


    Chris Case  1:12:29  

    another episode of fast off. As always, we love your feedback. Email us at fast dog at fast labs calm or record, voice memo on your phone, send it our way, and hopefully, we’ll play it in an upcoming q&a episode. Subscribe to fast talk wherever you prefer to find your favorite podcasts. Be sure to leave us a rating and review. The thoughts and opinions expressed on fast talk are those of the individual for Coach Trevor Connor. I’m Chris case. Thanks for listening.


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