Welcome to the Apparel for Cycling Podcast. I'm your host, Kolin Moore, joined as always by my co-host, Kyle Helson, and I want to thank everybody for listening as always, and I want to ask that you please subscribe to the podcast if you have yet already, and also recommend it to a friend. That is really the best way to get the podcast out there if you're enjoying it and get other people to enjoy it too. Please give us a good rating if you're enjoying the content on iTunes or wherever you are listening to your podcast. and also remember that we are an ad-free podcast so if you'd like to donate you can do so at empiricalcycling.com slash donate we have the show notes on the website we have some merch up at empiricalcyclingpodcast.threadless.com and if you have any coaching and consultation inquiries questions and comments you can please email empiricalcycling at gmail.com And if you want to follow me on Instagram at empiricalcycling, I am doing weekend AMAs in the Instagram stories. So if you want to participate in that, please give me a follow there. Last weekend's was on endurance training. We've got a lot of really good questions for that. So now, Kyle, tell me some thoughts you've had on how you think... The discussion of FTP testing may or may not have shifted over the last couple of years since my FTP testing article came out, which was early 2018, so almost three years now. Well, I think what's actually been nice is that I have noticed people... sharing the article who aren't you, which is good. And I think that more people are now beginning to realize that for a large chunk of the population, the standard cut and dried 20 minute test works, but then for another large chunk of the population, it doesn't. And therefore, there are other better testing methods that they could use that are more accurate. And then also I think people are beginning to also realize that there can be a difference in the results that you get, potentially very large differences in the results that you get from the different tests. And that's a probably extremely beneficial thing for the average person who might just be super confused about what all this stuff is. And maybe they've tried one of these other tests and they're feeling like, man, this makes... Intervals not really accomplishable. And then they think that they're doing something wrong or that there's something wrong with them. And that may not be the case at all. Yeah, I actually just, before we started recording this, was talking to somebody about, you know, his doing over-under intervals. And he said he had kind of gotten turned off of them because he was doing them according to his FTP by a ramp test. And he was like, yeah, they were basically impossible. because it was like it was like it wasn't like over under it was like really over and then kind of over so not really sustainable a death spiral of yeah yeah and you know one of the things that we talked about in the the last FTP testing episode which oh that was our first podcast so one of the things we talked about in that is you know if you want to do one of these other Tests, it's having some kind of historical context of, you know, when I've got this here, I've definitely got this FTP, you know, relating like a 20-minute test or a ramp test or whatever, you know, but now that we've, you know, looked at, you know, how ramp tests, which I believe was in Wattstock number 18 or 19, can be affected. by anaerobic capacity and the length of the ramp and everything like that. Your final ramp test value will be determined by those things and you can get very different numbers based on all that kind of stuff. And if you are looking to get a percentage of that and find your FTP, there's going to be a large amount of error in that. And so having historical context there, like for you personally, is really, really important. And I think that, you know, in that podcast, by memory, we alluded to the fact that if you want to do this kind of testing, it's fine. Honestly, it is. But you really need to know where you are actually at first. Like have a definitive, like personal, like this is the relationship between these two things before you like just going helter-skelter, like just, you know, testing FTP with, you know, all kinds of tests. This actually starts the discussion that I want to get into in this podcast, because over the last couple of years, there's been a lot of discussion on FTP testing that's just beyond the regular FTP test that I outlined in the article. So let's start talking about that kind of thing. But it's been that discussion, plus it's actually been... you know the quarantine of 2020 and no racing for a lot of people that has um that has really uh given me a lot more thoughts on FTP testing so the tests in the FTP article which is by the way linked in the show notes that's the one that came out in 2018 I only really use them with the people I coach uh initially um you know the progressions I mean the progression one two three I did did it go to four um no it's baseline then one two three So two or three of the people I've been coaching since then have actually just stuck with progression one, which is actually fine. But with just about everyone, we actually go straight to the very last version first. Interesting. Yeah. So the reason that we do this is because I'm coaching them. And with my feedback, You know, we can actually really hone in on what a good FTP test should look like and should feel like. And I've got access to all of their data, and I've got it in WKO5, and I can look at that and kind of get a ballpark of where their FTP is going to be. Ah, that makes sense. And so I have a good idea of where we should start. And I usually will, you know, the first time they do it, I'll probably ballpark it like 20 watts low for the first like 10 or 15 minutes. and then I'll have them ramp slowly until they find that sustainable pace, that edge of like, if I go a little harder than this, I'm not long for this world and if I stick it right here, I can go on for a lot longer. That's that edge that you're looking for and it's not like a one watt edge, it's like five to 10 watts, something like that. Just find that pace and then we'll look at it later. But one of the biggest mistakes that I've seen people make in doing this FTP test of this slow ramp is that they jump from the initial couple minutes under FTP to what they think their FTP is. And this has gone well maybe two out of 30 times. And every other time it's gone very badly. You know, in that article, you know, I knew that it was going to be for a general audience. And like in a lot of the other articles and podcasts that have come out, and in talking to a general audience and, you know, versus in my practice as a coach, I do things differently. because in coaching I'm there to guide somebody and with an article like that I'm not there to guide somebody. So that's why rarely do I actually use that kind of progression unless somebody's typically fairly bad at pacing themselves and we need to work on that for FTP tests which does happen certainly but most people are actually really good at that kind of thing. That makes sense. It's a useful skill generally that, yeah. It's good for athletes to have. Yeah. All right. So, well, speaking of pacing, though, let's talk about pacing and erg mode. Now, in the Instagram AMA stories, I actually get a lot of questions on it there, and there's also been a lot of discussions on if you can use erg mode for these tests on other forums. And, you know, can you actually have an erg mode test? And is it okay, actually, is probably the bigger question. and the answer is obviously it depends. So drink. Thanks for listening. Yeah. So in a way it's fine if you're just looking at your power curve to see how long you can hold watts and you know regardless of the test result you can look at that and go all right this is my FTP based on the power curve based on that inflection point that we're always looking for. If you do like erg mode at x watts and It may or may not really be your FTP. You know, you want to look at your power curve versus log time and you can actually see, you know, beyond FTP, where's that linear region? And then where it'd be, you know, before the FTP, where's that linear region? And like, look at that inflection point in between. That's what you're looking for, really. However, ERG mode defeats one of the big points that is embedded in my type of FTP testing. which is being able to feel that fatigue point over which you'll fatigue faster and under which you'll fatigue slower. If we want to take this to a ridiculous but logical extreme, here is a very long and dumb way to do FTP testing but may actually be the most accurate for a power-based. So you're going to set your ERG watts, well you're going to suspect your FTP first. Set your ERG to 10 watts below your FTP. Ride as long as you can at that wattage. then Rest, and then you set your ERG modes to 10 watts higher than your FTP, and you hold that as long as you can again. And you're going to repeat this process until you look at your power curve, you know, power versus log time, which, by the way, is the WK05 default, and you're going to see that the point of exhaustion beyond FTP is more or less linear, like I just mentioned, and when you get above FTP, that you know it's it's linear but it's like a different slope you know it's steeper yeah yeah exactly um note this is the least time efficient way I said it was a dumb way to do it it's not dumb it's just like the it's like the brute force method yeah uh what would you call it like a Markov chain or something Yeah, it's like a random search. I mean, it's kind of like a binary search. Like, you pick a number, and then you go halfway between this number and the next number, and then halfway between this, you know, yeah. Yeah, and yeah, it's a long way to do it. Don't do it this way. But let's take a concrete example for somebody off my roster. This person has a 200-watt FTP, and they can hold it for 40 minutes. So if they go 5% lower to 190 watts, They can do this for 60 minutes or 150% of FTP. If we go 10 watts lower, 180 watts, 200% of their TTE at FTP. At 170 watts for 225%, okay, right, so et cetera, et cetera, et cetera. Now let's look at 5% higher or 210 watts. They can hold this for 21 minutes or 50% their TTE at FTP. If we go to 220 watts, it can be held for 10 minutes or 25% of their TTE at FTP. So that's really that inflection point that you're looking for. Like over this power, I'm going to fatigue a lot more quickly. Under this power, I fatigue a lot more slowly. That's the definition of FTP. Like that is the definition of that threshold that everybody in the sciences is always looking for. like there it is that's it's that simple and that's um something that you can feel more or less uh we'll talk about that in a second um people have probably experienced this sort of sensation just riding around if you've ridden um you know if you you come up on a steep hill and you you try to you know Hall Ass up the hill and then you realize it's a little bit longer than you realize. If you started off, say for example, if you start off too far above your FTP, you will find that you die off pretty hard because you do fatigue so much faster whereas if you were maybe a little more conservative and you started off closer to your FTP or under it, you'll notice that you fatigue a lot slower. And I think... It's something that maybe people have experienced but never quite put their finger on like, oh, yeah, this kind of makes sense. This is the term to describe this sort of sensation that you feel. All right. And so let's actually move on to critical power and ramp tests. Like, we just touched on ramp tests and we did in that Wattstock episode, but I want to address this a little more directly. Actually, a new paper came out on critical power versus MLSS, maximum lactate steady state, which is just FTP, more or less. And they find that critical power versus MLSS, they find FTP is actually significantly lower. And there is in between what they call a quote-unquote gray zone between your critical power and your MLSS. which is kind of interesting to me because a lot of this stuff is based on exercise intensity domains and the descriptors of these domains but I gotta be honest that I never think about exercise this way. I don't because I think about what are the adaptations we're trying to make and I don't Yeah, I don't think about exercise intensity domains the way that a lot of other people might who came up through the more traditional exercise physiology education routes. You know, because I obviously come straight from biochem and systems phys. And, you know, to me, I think about what's going on underneath rather than thinking about, you know, what's happening with the VO2 kinetics. Person to Person. So I don't think we can actually define VO2 kinetics as determining exercise intensity zones in terms of moderate, heavy, severe, and extreme, which are the typical four that we see. You know, because the bounds between moderate and heavy might be, you know, the gas exchange threshold or LT1 or something like that. And the bound between heavy and severe might be critical power. And, you know, this introduces a lot of problems because, you know, if critical power is overestimating FTP or MLSS, for instance, you know, we'll get that, you know, the two very different, you know, fatigue responses like over FTP will... Fatigue a lot more quickly, and under it will fatigue a lot more slowly, but this is still in the heavy domain, but what's happening here, therefore, you know, but if it's in the heavy domain, we're just thinking about heavy exercise, then it doesn't matter because it's all in the heavy domain, right? And this is just one of those weird things, or then we get to define this as the gray zone between FTP and critical power as a, you know, and if we're really going to have, you know, FTP and critical power being... you know two distinct boundaries of different exercise intensities then you know if depending on how we measure critical power you know we'll get this uh you know Gray Zone between, or maybe we won't if critical power gets defined differently, you know. So Kyle, talk a little bit about the, you know, critical power modeling. We did cover this in Wattstock number eight, by the way, and I'm sorry for the math mistake that we left in there, if you heard that episode, but I honestly, I thought it was funny to leave in. So I left it in, and a lot of people did not think so. But anyway, sorry, Kyle, talk about critical power. Generally for critical power, like, I think it... This happens a lot in science, and especially if anyone has ever done any type of modeling, or if you've done, if you have experience with, you know, my background is in physics, so this happens all the time, people will take a model that is known to work well in one case, and then see if they can reuse it, and if it works well in other cases, and sometimes it works, and sometimes it doesn't. And part of the difficult part with any sort of modeling or predictive assessment is that you have to understand the limitations of the model that you're using and know when it is both when it is valid and when it's not valid. And so this is probably one of the problems with this. Sort of misuse of critical power to, oh, your CP60 or whatever, people say, oh, that's equal to your FTP. And for some people it is, and that's great, and for some people it isn't, and that's also fine. But it is kind of like a, you run a risk of extrapolating the conclusions of a model outside of the domain in which it is. Valid. So critical power is really useful, sort of above FTP, like you said, you said 3 minutes, 8 minutes, 10 minutes, these, you know, sort of roughly VO2 max type ranges, and then it gets worse and worse and worse if you keep extending it out and out and out and out and out. And so that is the risk that you run, that like, okay, so if it works at 10 minutes, maybe it works okay at 20 minutes, maybe it works okay at 25, but the farther you extend and extrapolate that curve out, the less accurate the results are going to be. Yeah, the less able you'll be to predict them, more or less. Yes. Because the human power curve doesn't actually resemble that perfect hyperbola. I mean, in a certain time domain, it will. But as you get longer and longer and longer, here's one of the things that makes a big difference, is in shorter time ranges, you're actually using more muscle mass. And as you fatigue, like we saw this in one of the VO2 Max episodes where somebody does a really hard initial sprint, like all out, like 1,100 watts, and then they fatigue, and in the last two minutes, they're at like 250, 300 watts, and they're at VO2 Max, the same effort, and they're just at VO2 Max the whole time, and you see the EMG actually, it peaks and then it fades. In the steady state, the three-minute steady state, you actually see the EMG growing. Like, it goes higher, but it never hits that first peak. Because even as you hit maximum fatigue, you know, there are mechanisms that are preventing you from actually recruiting more motor units. And, you know, you're not going to be able to get there. And so the difference in muscle mass and the work capacity of more muscle mass makes a big difference when you are looking at the critical power curve. you know the human power curve kind of look like it does as opposed to like you know people thinking that you know if you just eat enough and if you have enough electrolytes and everything you can actually sustain your critical power forever right which is the the key one of the fundamental assumptions in the critical power model is that you could theoretically work for an indefinite period of time which is just not true so that could kind of tell you that in that conclusion, like the closer you get towards very long, long, long time values, the worse and worse and worse the predictive power or predictive ability, power is kind of a confusing word to choose, the worse the predictive ability is going to get. Yeah, and that's, and so, you know, we do go into that in Wattstock number eight. Honestly, I don't remember much about that episode. but I knew I know that a lot of people are going to listen to this episode and not that one so I so I think that's why I wanted to include that here and also because of that paper coming out of like that gray zone and also there's another way to look at it in terms of like you know critical power and MLSS of you know if you ride to fatigue at FTP or just above or below you know some other thing like there you may or Some people actually will define it as a range at which you can actually exhaust yourself riding over a threshold but not hit VO2 max. And that is a range that is probably going to vary day to day and with fatigue levels and your trainedness and your trained state and how much glycogen you have in your muscles and stuff like that. So that should change day to day based on all that stuff. That's one of the things where I try not to think about that kind of thing because, you know, if you listen to the Via 2 Max series, you know that I have other ways of making sure somebody's working at their Via 2 Max. And, you know, so I don't try to think about things like that. I always try to think about what's happening, you know, at a very first principles level, which, honestly, I don't like saying because it sounds douchey, but that's really what it is. I try to think about what's happening. at the deepest possible level in terms of adaptation, and then I build everything up from there. So let's also address the RAM test very directly. We just sort of did, but RAM test versus critical power test, I think I'd actually rather take a critical power test than a RAM test. With a critical power test, I can sneak in a 30 to 40 minute effort. You know, as one of the test durations at the expense of the model fit. And, oh yeah, it was one stock number 18 for ramp tests and VO2 max and stuff like that. All right, so one more thing with being able to feel out your FTP that I have found extremely interesting this year specifically. You know, typically since we don't measure FTP day-to-day really, It can be difficult to assess how much it's going up during training, obviously. So I usually stick to one wattage and pushing it way, way, way out if possible. But there's a disadvantage here that I've really noticed. You know, I noticed it before this year, but this year has really, really made it apparent. That's happening with more people that I wouldn't have expected it to happen with. The disadvantage is that it can wear a rut in your perceived effort. Does that, do you kind of know what I mean, Kyle? Do you see where this is going? So, yeah, so that makes sense. That if you've done so much work at this one prescribed intensity, that this has become so second nature that working outside of this prescribed intensity is very foreign and actually makes you feel like you're working harder and it throws off your perceived exertion. Yeah, exactly. Yeah, you get used to that one pace and so when it comes time for your FTP test, and you're ramping and you find that pace like it's at that same power level that it was before even if your FTP has gone up. So I saw this a handful of times this year in a couple people whose FTPs had actually gone up by 15 to 20 watts after some hard training. And the FTP test was just about the same as before. But then instead when they went on a time trial or a long Strava KOM or something like that. They actually managed to go much, much harder. And then you look at the power curve and you go, that's that inflection point. It's gone up. Even if the TTE has gotten a little shorter, that inflection point is still equally valid. And I think that's interesting because you talk about adding in a climb and it gives you that external motivation to push a little bit harder. and it's a really interesting that you can just find this little bit extra motivation which I'm sure people have experienced like whether it's listening to music or finding yourself trying to beat your friends up a climb or for a KOM or for a timeline sprint or something just that little extra external factor can coax this extra performance out of you that you maybe weren't expecting on that day. Yeah exactly and especially this year when there's been no racing For a lot of people, I mean, racing's just starting to come back in some places, which is fantastic, and I hope everybody's doing it safely. But with all the extra training that's happened this year, you know, I had to, you know, work in new ways to look at people's FTP and to test and kind of like sneak tests on them because they're not doing time trials, they're not racing, they're not getting in these harder efforts. where we would normally see like, oh, this person's FTP went up and they set a new 40-minute power in this race. That's fantastic. So we set a new FTP. And that's the kind of thing where in a normal season, we would be able to account for this kind of thing happening. Because if you take a break from FTP training, you do some racing, you do a little maintenance work, you kind of ignore that intensity level. And then a couple of weeks after you kind of forget about it, you go back to it, and, you know, then it's like new again, and you go, oh, yeah, okay, I know this perceived effort, oh, I can do this harder than I could before, this is fantastic. And this season, that has just not happened to a lot of people, it's just been, you know, training, training, training, training, training, and you've really worn those ruts deep sometimes. I think, I think it also especially probably because people are thinking like, oh, the pandemic coronavirus time, it's a great time to just like, Get in way more volume than you've ever gotten in ever before because you don't have to worry about racing and maybe you're working from home so you can be more flexible with your ride schedule. So it makes sense. Like, you know, you try to make lemonade as best you can out of a strange situation. Yeah, definitely. Well, so what of my solutions to this besides, you know, getting people to go out and, you know, do shorter tests like they wouldn't usually before? Like, you know, 30 minutes or something. I'll just give them like, go as hard as you can for 30 minutes instead of just an open-ended FTP test, which is the final progression from the article, which is what I usually assign. And so this summer, one of the other approaches I've had to FTP testing actually relies a lot more heavily on the WK05 model. which obviously means making sure you've got all your time ranges pretty well accounted for. You want to make sure you've got a good sprint, like 10, 15 seconds in there. You want to make sure you've got a good 30 to 60 seconds effort in there, a good like three to six minutes, and then a good, you know, maybe like 10 to 30 minutes, and then a good like, you know, hour to hour and a half, something like that. You want to make sure that the model is pretty well filled out. And the way I train people, the model is pretty well filled out for the most part. Sometimes we'll lose like a good 30-second or a minute effort here and there depending on how much anaerobic training we've been doing. You mean you don't like just to drop random one-minute all-out tests on people for funsies? Well, what I do now to maintain the model, I tell them that that's what it's for. I've discussed this with them a lot. Close your eyes and think of the model. Yeah, exactly. Well, think of England or the model or whatever you need to. And, you know, and a lot of the time, actually, their one-minute power has gone up and they're pretty happy. Like, hey, how's this happening? It's like, we'll talk about it later. We'll do a podcast episode on it. It's a long answer. I think that makes sense, though. Oh, no, sorry, go ahead. I think it makes sense, though. Like, I think a lot of people, you know, cycling is such a delayed gratification sport in so many ways that being able to go out just one afternoon, bust your ass, and see an improvement is really satisfying, especially if you don't have racing. Yeah, like I just mentioned, actually, one of the things that I've been doing is giving people, like, a time range to test without thinking about the pacing. or, you know, having it open-ended like a 15 to 25 minute test, which is mentally easier than a straight up 20 minute test because if you blow up early, so what? Like you are still going to, you know, have, your FTP is still going to come up in the model. It doesn't matter if you blow up at 17 minutes or 21 or whatever it is. And also like if you undercook it, then you can push longer. If you overcook it, then that's fine. And, you know, I also think that, Using the model a bit more for FTP testing helps because with all the extra training people have been doing, more than in normal years, because in normal years you get a lot more rest and then you race and you rest some more and you race some more. This year the racing usually dictates where the rests go, but this year it's been some people can just keep pushing and pushing and pushing. In this approach, with all the training, doing normal intervals. Can also lead to higher power values in the FTP range, like 30 to 60 minutes. Like one of my athletes, you know, he gained 20, 25 watts in his FTP, and we only did like his last FTP test in like April. But since then, we've seen that inflection point in his power curve go up and up and up. So in addition to doing... Kind of unstructured testing just to feed the model, you know, in the range of like 20, 30, 40 minutes or whatever. And, you know, an hour, 80 minutes, 90 minutes, something like that. You know, you can do this kind of thing with other types of intervals. You know, you can do over-unders for 90 minutes, you know, and even though it's not, you know. Strictly Steady State. You know, 30 seconds over every now and then is not going to actually affect your average all that much, maybe a handful of watts, depending on how often and how long you do them. But really, the point of something like that would be to, like, leave an open-ended interval. This is something that I give to people sometimes when I think that they've really, you know, gained a lot of power. And so I'll give them... you know over-unders or something like that or FTP with bursts or you know just a straight up FTP interval or just give them a wattage just like hold this as long as you can and there's no wrong answer to whatever they do and a lot of the time with something like that that's when we'll actually see some of those new FTP values come up and the other thing that we can do is Zwift racing but not something that you're comfortable with, something where you're a little outmatched so that you have to push hard the whole race. So instead of being able to like sit in, then you actually have to like hammer the whole time and it's got to be hard. So, you know, if you're at four watts per kilo in the races, I forget the race categories, but if the race is like 3.8 to 4.2 watts per kilo, you're going to be fine. you know but if you're at like 3.7 watts per kilo like that is a good race for you because you have to push really hard to stay in it um that's good I mean I think for a lot of people I think hiding things or keeping it black boxy is less less good but um also To bring this back, you know, in case you were racing, sometimes in actual races where people race really hard and have to hold on for dear life, it also works as an FTP test. So this is just like a, you know, pandemic-friendly 21st century version of that. Yeah, and that's the kind of thing that, you know, during a normal race season where we would be able to assess somebody's FTP increasing. And we're just not getting that this year with most people. So there's another question in here that I've gotten a couple times, which is on heart rate. You know, can we train to heart rate? Can you just ride at this one heart rate as, you know, an indicator of your FTP? Like, I know it's 173 beats per minute, so I'm just going to ride this heart rate for as long as I can, and then that's going to be my FTP. There's a lot of variation in heart rate at FTP. So you're at like 160, you're at 170, you're at 180. I mean like one person doing an FTP test can start at like 160 and end at 175. And it's still their FTP. I think this is also just a, you know, we've talked about this, about some of the pitfalls of using heart rate for things before, but, you know, it gets you, it's, it can be useful, but it is not a perfect substitute for other metrics. Yeah, for sure. There are really cool ways to use heart rate that we're actually going to be talking about in an upcoming episode. Let me try that again. Yeah, there are really cool ways to use heart rate that we'll be talking about in an upcoming episode. So it's obviously not like a useless metric, you know, because especially early season, like we talked about plasma volume and heart rate in one of the VO2Max episodes. You know, if you are just getting up off the couch or you haven't done a lot of... Endurance Training yet and you want to test your FTP, your heart rate's going to be jacked compared to where it will be in a couple months. And also, you know, you can have caffeine and stuff. So, you know, it generally tends to be a less reliable method of FTP testing. So, here's one of the other things I got as a question that I think is a really good one to address and I don't remember if we addressed it before. So, here it is. When to test. You know, the standard answer is every four to eight weeks, you know, sometimes less often than four to eight weeks when you're really pushing for just a couple percent more each year. The kind of thing where like, you know, five or 10 watt gain, you know, in six months or a year is worthy of celebration. Like you don't have to test that often because you know you're going to be pretty close to what you can do. Right. And I think that sort of goes hand in hand with either, you know, training history. You know if you're the type of person who has reached that sort of period in your athletic career where 10 watts is a huge deal or not. Yeah, and some people have asked, should we just add 5 or 10 watts to our FTP every 4 to 8 weeks? The answer is no. Your FTP may not have gone anywhere. So I think also with the can you add just 5 watts or whatever, maybe you could claim that if For every person, that slope of fatigue was the same, you know, as a function of time, but it isn't. So there is no hard and fast rule where you can say, oh yeah, if you've done this much, you know, you're definitely going to see a TTE go up this amount or the wattage that you can hold at this certain time is going to go up by this percentage or this number of watts. But again, that exact slope of that inflection of that. Inflection Point after your FTP and just before your FTP is not the same for everyone. So you can't really just say, oh yeah, five watts, everyone can just add five watts, blah, blah, blah. Yeah, exactly. I wish we could. Yeah. All right. So another good question is on precision. How precisely can we know FTP and should we define FTP? Because obviously if you look at... You know, a really complete power curve. It is not an actual point, which, you know, I think can kind of get lost on us. So it's sort of like saying where in this curve do we define FTP? So I think, you know, like you said that there's this region where above which you fatigue a lot faster and below which you fatigue a lot slower. And so you kind of want to pick a point. and then you just call this your FTP. But there's not like a specific spot that like, you know, oh, the literature, oh, the general consensus is it's this exact point on this curve and for everyone that curve is going to be shaped a little bit differently so you wouldn't necessarily even be able to say, oh, it's this amount to the left or right of whatever shape in this curve. Yeah, it's kind of imprecise and, you know, personally I try to If I've got that actual nice curve in the power data, which is really rare, but when it's there, I always try to pick a point that's kind of in the middle of it. So if you look at your power curve on a log time graph, I just kind of try to imagine two straight lines coming to a point in the middle and trying to find that point in the middle, which may actually be a little lower than WK05 will give it to you. if the model is really fitting well over there. But that's where I would rather go. Because a little less is always better than a little more. Because it's not a well-defined line. I mean, even due to the actual physiological reason of why FTP occurs is not a sharp point. It is a curve. And we'll talk about that in another episode, a very, very much later episode. I kind of want to keep that one under my hat for a little while. But yeah, I usually say within about five watts is fine. Probably better to go a little lower so you can, because you know, like if you're doing, you know, 45 minutes at 250 watts and you can do 50 minutes at, you know, five watts lower, that's not a big difference. And, you know, over-precision here is something that can, Drive People Nuts. And, you know, there's one other thing to think about, which is like, you know, how much does your FTP actually change, like day-to-day, week-to-week? Because I know a lot of people will say, you know, my FTP has changed a lot in the last week, or like even what you can hold for intervals. That's a big one. Somebody can hold 250 watts this week for a 3x20 and only 230 watts the next week for 3x20. Does that mean your FTP has gone down 20 watts? Physiologically, the answer is no, absolutely not. But the real answer is you need to rest and eat. Yeah, you're hurting. Yeah, it doesn't change that much. And people who try to micromanage their FTP every week or two, like changing it like, oh, this is about where it is this week. Physiologically, it's not going to change like that, that much. It's, you know, due to the reasons that FTP occurs, it's basically impossible to have that much change in your muscles, you know, that quickly. I also often come back to the fact that you're using a power meter, and the power meter has a prescribed error, like if you have maybe a less expensive one, it may be plus or minus. 3%. And if you have a more expensive one, it may be plus or minus 1%. But that means that even the number that your power meter spits out after the end of the day is not necessarily the exact number to within a watt. Like if your FTP is 300 watts and you have a power meter that is plus minus 1% error, well, the error alone is going to blow out this like, oh, I know my FTP to 1 watt. Yeah, no, that's never ever going to happen. So now let's talk about one more thing that's been kind of bugging me. It's not that much related to FTP testing, but it is related to defining FTP, which is kind of an open debate to some people, and it's not to others. Now, you know, we've mentioned many times, and I know a lot of other people have talked to Andy Coggin. and confirmed it, that he meant FTP to be a substitute for work rate at maximal lactate steady state, which really just does manifest as that inflection point in the power curve. And we'll talk about the physiology behind that later. But a lot of the times in the literature, because of the way FTP was marketed by Hunter Allen and others probably, You know, even in that book, like, you can tell, like, what page did Andy write? What page did Hunter write? Yeah. So... They needed a more active editor. Yeah, a little bit. So it's defined a lot of the time in the scientific literature and the exercise phys literature as just 95% of your 20-minute power. I mean, we've been over this debate many, many, many times. And so, you know, so to some people, I think, they're... This is still a point of confusion about the definition of FTP. And there's another thing in here actually that should be addressed, which is critical power having been in the scientific literature and the exercise physics literature for so much longer than FTP or Maximal Lactate Steady State. You know, it leaves this question, did a poor PR campaign rolling out FTP initially doom it as a scientifically valid metric? the same way that if somebody uses one of my articles as a strict definition of a thing, if I've tried to generalize it for an audience, does that make it less valid? I think it doesn't necessarily make it less valid, but it certainly makes it seem less valid in the eyes of public perception, perhaps. I think that It can suffer from this sort of idea that if even an incorrect statement is repeated enough times, it becomes the truth. Illusory truth effect. Yeah, and so you run into this problem where, oh, well, now you have to spend, it's not that... different than trying to convince people that lactic acid is not why your muscles hurt after exercising, right? That like it has just become this part of the ethos and even well-trained scientists can make mistakes and it happens, you know? Well-trained scientists are still humans, still prone to error, still have all of the innate human biases and so is it Forever Doomed? I hope not. But does it have like a kind of a steep hill to climb in terms of sort of rectifying the actual definition? Kind of. Yeah. And actually, you know, to bring this back to earlier in the podcast, talking about exercise intensity domains and whatnot, you know, this is one of those things where, you know, Maybe I see everything differently because I'm not trained classically in exercise physiology. I'm trained in physiology and biochemistry. And so to me, when I look at the human power curve and what are we looking at? What are we training? How do we do this? How do we get better performances? That's where my understanding starts. And a lot of the times it seems like for some folks, the understanding starts at the definition, of a larger phenomenon. And then they have to maintain that definition of the phenomenon as they dig into the actual underlying physiology, which gets messy. The other thing you run into is that the dictionaries are not necessarily the same between the athletes and coaches and then the exercise physiologists in the lab. And this can also be a really big problem when you try to compare notes if you're working off different terms and definitions and the translation isn't good. If you talk to someone and they're convinced that FTP is defined as 95% of 20-minute power, then of course no one's going to, if a scientist talks to them and they want to talk about Maximal Lactate Steady State, or this or that, and they completely miss that association of FTP with Maximal Lactate Steady State, well then, it may not ever enter into their mind that, oh, this is actually what FTP is supposed to be and not this other thing. Yeah, it's really two interesting approaches to the same problem. And, you know, it seems like it's actually like a path function and not a state function of how you get there, you know, kind of influencing how you, you know, see the underlying physiology. Oh, for sure. And I think you run into this in lots of other fields where, and again, I'll speak from my background in physics, where luckily for the most part, for example, particle physicists and you can be an experimental particle physicist or a theoretical particle physicist and luckily they do communicate enough such that like you know the people running the LHC and taking the data are not like using completely different terminology than the people who are are coming up with the theories that are being tested and vice versa. Like, luckily, they have the same background. They all have the same training in physics. But in this situation, you don't have that. And very often, you have these people coming at it, like you said, from two very different paths. And therefore, just having their entire worldviews be different on this topic, even if they are looking at two sides of the same coin. Yeah. And, you know, it's funny because in physiology and threshold testing, in the literature specifically, everybody is really trying to find the same thing. We are all on the same page there. You know, it's just that I think some people think about, you know, the historical validity of something, you know, it's longevity being an indicator of, you know, infinite validity of, you know, this theory is great, like the critical power curve. Why wouldn't we be able to maintain exercise forever if we just eat enough? Like, if your FTP is like 80 watts, yeah, maybe, because you can actually eat enough carbohydrates to supply that kind of thing. Maybe. But there might be more reasons that we fatigue, you know? It's definitely not at 200 watts and really not at 300 or 400 watts. But we are looking all for that same point, and that's why, you know, to me, the real... Long way to test threshold is to like pick a power level, see how long you can ride at that, add 5% or even 2%, subtract 5% or 2% or like within, you know, make sure that you're not within the power meter error of your original estimate and then, you know, look at, you know, is it, you know, can we add 50% and subtract 50% if we go lower and higher from this power value? Like that's really that threshold. and other definitions of threshold like even VT2 and stuff like that. All of these other things that are usually correlated in people who may not be well-trained actually tend to decouple in people who are well-trained. You can hit VT2 before you hit MLSS, before you hit whatever else. It kind of depends on the person and how you are actually looking at defining your terms. And having rigid definitions of these things I think actually does a disservice. Which is why, you know, my definition of FTP has always been like, look at that inflection point. It doesn't matter what we call it. We're looking for that, you know, fatigue inflection point, regardless of everything else. Yeah. I think another thing is, you know, there's a lot of inertia in science to stick with terms or theories or labels, nomenclature, whatever. And it can be... basically impossible to overturn despite people's best efforts to change it. So that may be a losing battle for some people. Yeah, so that's really where I'm coming from with everything. And, you know, once in a while, I have jumped into a debate on Twitter about like FTP versus critical power and whatnot. And, you know, honestly, I do regret it every single time. I'm not going to do that so much anymore because we are all on the same page and, you know, we are arguing over minutia when we are all really looking at the same point of fatigue, however we define it. I have a rant that I will save that about... Nomenclature of Things in Science and how it's always terrible and like you want name like critical power. Seriously, do it now. There will be very few chances for this in the future. So like for name critical power, like critical? What does that even mean? Like I and it gets worse when we name things after people because like what is the claziest claperon relation? Like that tells me nothing about what it actually does. I'm just. I can go on and on about those things. But critical power is not a particularly descriptive name for a model. And so if you're someone coming at this from complete naivety and you read something critical power, it's going to take you N pages of reading just to figure out what they mean by critical. What is critical about it? Who knows? And same thing with functional threshold power. Even that's not... Great, right? Like functional. So does that functional kind of to me has one definition, but to other people it has other definitions and connotations. Threshold, well. Actually, well, you're funny about functional because that's always bugged me about that name too because I hear that and I think it's functional, which means it's good enough for now to use, but it's not really what we're after. Exactly. I have the same feeling that it's like a proxy for something that We're kind of sweeping under the rug or like this is our approximation. And then threshold, obviously there are like 18 different thresholds that people want to define in exercise science and so calling this one threshold isn't really illuminating. Power, okay, power is fairly well defined. Yeah, and I just wish that in general people in science were way better and physics is... by far no exception to this. Physicists may be the worst at this actually. You should read more exercise physiology papers. So I think in general this is something you run into whenever you try to communicate scientific topics to lay people is that Some scientists picked this terrible, terrible name and now you just got to spend half your time explaining what this name means and why this name may or may not make sense given what it actually describes. Neil deGrasse Tyson has done a great job of campaigning for the changing of the name of Dark Matter to Fred. Yeah, I mean, it's just as accurate. Well, maybe not just as accurate, but... I could go on. But yeah, I think this is one of the other reasons, like you said, is like, is it a poor PR campaign? Yes, but it also goes hand in hand with just bad nomenclature in science being like the theme. Yeah. Yeah, anyway, so I hope that this has been a little more informative as to where I'm coming from with threshold and testing and my personal methods and how I really do things. Um, because, you know, even in that first, uh, first podcast episode, you know, I didn't know how to express myself, you know, to the point that I do now, you know, what was this like a year and a half later or more. Um, and, um, yeah, I hope this answers a lot of questions that people have had. So if any listeners want to, uh, ask me more questions about threshold and threshold testing, uh, check out the Instagram AMAs on the weekends. Especially when Kyle throws a curveball question. Always there to keep you on your toes. Keeping you on your toes. The most DMs I get are always like laugh reacts to me answering your questions. That's what I'm here for. That's what I'm here for. Kyle, would you like to tell the people what your last question was on endurance training? I think I have to leave it up to the listeners to figure that out. Alright, anyway, thank you everybody for listening. Again, please subscribe to the podcast and share it if you have enjoyed the content. Give us an iTunes rating or a rating wherever you are listening to podcasts. Remember, we're an ad-free podcast, so if you want to donate to the show, you can do so at empiricalcycling.com slash donate. We have the show notes up on the website. We have merch at empiricalcyclingpodcast.com. And if you have any coaching and consultation inquiries, questions, and comments, you can please email empiricalcycling.gmail.com. And with that, we will see you all in the next episode. Yeah, thanks a lot.