Welcome to the Empirical Cycling Podcast. I'm your host, Kolie Moore, and today we are joined by Empirical Cycling Coach Fabiano, which everybody has heard a lot about. He's been on the podcast now and then, and it's time to bring him back for a full episode. So thank you, everybody, for listening, as always. and if you are new here, please consider subscribing to the podcast if you like what you're hearing and if you are a returning listener, thank you so much for coming back. We absolutely love having you. If you want to support the podcast because you're liking it so much, you can always give us a nice rating and a really glowing review wherever you listen to podcasts. We appreciate every one of those. You can also donate to the show at empiricalcycling.com slash donate because we are completely ad-free content to help you out with your cycling gains. and you can also hire us for coaching, empiricalcyclingatgmail.com or head to the website and go under the contact tab and got a little intake questionnaire over there if you want to fill that out and yeah, it's a good time of year, we're kind of late February, no, it's March already, we are early March and a lot of people are getting going so if you, even if you Don't want to work with a coach right now, we are happy to keep you on the right track if you are self-coaching, so that would be a consultation, and yeah, if you are interested in a coach, that's kind of our ultimate Patreon, so we love coaching people, and we always have open spots, and if you want to ask questions for the podcast, Empirical Cycling on Instagram, and I also do a weekend Q&A about training, so go give me a follow over there if you have any questions on training, and I was thinking about opening up an after-hours kind of question box for the podcast for when people have questions for us to answer here. And we may or may not get to some listener questions today because we actually have quite a bit on the menu because Fabiano has written a couple of really interesting articles that have been published on the Training Peaks blog in the last couple of months. And I think it's probably a good place to start by reminding people that Fabiano has a list of accomplishments longer than my arm. He is an MD, PhD in... What was your PhD in? Molecular? Molecular Medicine. Molecular? Yeah, with a major in genomics and proteomics. Right, okay. So he's exactly the kind of nerd that I am, except he's way, way more academically accomplished. And it's fascinating when you watch somebody with so much knowledge write an accessible Training Peaks article. Because I think by just reading the articles... People wouldn't know that you've got the level of knowledge that you have. And I think that that's actually a great compliment because, not to throw too much shade, because I certainly do this myself, I am absolutely a perpetrator here, is that sometimes people will try to be too technical in their popular articles like on the Training Peaks blog. But yours, I think, you've got the list of references, but they're so accessible for the most part. The third one we'll talk about. That's a little less accessible, a little more technical, but that's okay. I think it's well within the wheelhouse of most of our listeners. But the big one here is that your articles on RPE and feedback, I think that they're actually kind of two sides of the same coin, obviously. But I wanted to ask you about those. So what was the genesis of writing these articles on some pretty basic stuff? Yes, that's, if you look at my history, my second master in exercise physiology, it was in the Department of Education in the U.S. And there, I was always linked to the education. And I really believe that when you are working with athletes, you need to educate them, help them understand the tools so they can be better informed. When working with you as a coach, or even for self-coached athletes, to really understand how the tools work. And for RPE and even workout feedbacks, I always wonder, I always struggle to find something to share with my athletes that would explain it to them the way I would like them to understand. And that link goes with how I work as a coach. In 2017, when I started serving Training Peaks as a coach educator, I had this opportunity to write this article. So the first one I wrote was on the RPE. And it's interesting because the RPE, there are some misunderstanding on how these scales work. And they were created a long time ago. And most people don't take the time to understand the history of the... the tools that we use. And that's another aspect that I like to value in the science. People tend to believe that some articles, they have like an expiration date. And actually, I don't think they do because they really bring the evolution of the science behind all the exercise physiology concepts that we use today. So when you read the paper from 19... 1964 or even older papers. It's really a different experience to see how the scientists saw the knowledge at that time. Yeah, I mean, I'm sure you've heard about like reviewer feedback being like, like, hey, this article's from like the 90s. Can you get something more recent? It's like, no, this is the definitive article. It's like, I remember in a lab report in school once. I made a reference, my first reference was to Darwin, Origin of Species. And the feedback I got was like a big green checkmark, like a great reference, I remember was the note in the margin. I was like, hey, that's all right. Okay, cool. I'm on to something. And it's like, you know, if you're going to talk about evolution, you might as well go all the way back to the source because like, that's the genesis of the whole idea. I've had a couple discussions with people recently on the origin of RPE, and actually more broadly, even on the origin of the conventions that we have in science and exercise today, because I think understanding the historical path that we've taken here, a lot of the time, we're not looking at a state function. Like, why is this thing here? It's like, it's a path function. Like, there is very much historical context to this. So, what's the historical context to RPE? So, Gunnar Borg, that's his first name, when he was trying to... We'll link the original articles as we refer to them in the show notes, by the way. So, yeah. Good. So, he was trying to understand the relationship between some physiological functions, like heart rate. and the work that someone was doing during his studies. So the first one he did was trying to correlate in a young man the heart rate and the work. And as we know very well in cycling, you can measure work with a power meter. So he was studying the progress of intensity with more and more watts. The intensity increase, he noticed a very linear relationship between heart rate and the work being done. So based on that came the first scale, the RP, the rate of perceived exertion. And it's odd scale, because if you know well, it's a scale that goes from 6 to 20. And everybody, many people don't ask. Why is it 60 to 20? What's the sense behind that? If you ask someone that's in exercise and he says, oh, this is a 10, the perceived effort. And if you multiply that, especially if it's a young man by 10, then you have a value that's really close to the real heart rate, which might be around 100. So you go from resting around 60, Bits per Minute up to what's the expected maximum heart rate for a young man, which is around 200. And that's how the scale was developed and validated, as simple as that, but that also explains why it goes from 6 to 20. The problem is, after he used or he applied the scale to other age groups, he noticed that It didn't work as well as in young men. So for kids or elderly people, the linear relationship was a little bit different and the scale wasn't as accurate as it was before. So that's when he came with the second scale, which is the CR10, which is a category ratio scale, which is related to some other very interesting aspect of Perceived Exertion, which is your psychological makeup, but also some markers in your system that doesn't follow a linear relationship, for example, lactate or pain. So when you are doing exercise, we know that very well from VO2 max intervals or spring intervals or high-intensity intervals that They hurt a lot more. It's not linear compared to the pain that you feel when you're doing endurance or tempo workouts. But that's why if you look at the CR10 scale, especially if you don't see the modified versions of the scale, if you look at the original scales, the RP, the linear one, it has a distribution of values that's very... evenly spaced between each intensity because it follows a linear correlation. But if you look at the CR10 scale, it follows an explanation function. So it starts in the, even at the scale, the printed scale, if you look at that, you see the first values, values are very close to the other, but as you increase intensity, just like with an explanation function, They increase the space, and also at the scale, you can see the spacing increases. Yeah, so, well, to give you, I'll read this out, because people, you can just Google Borg CR10 and go to the images search in Google, and that'll give you kind of, but it's like zero is like nothing at all. Then it's 0.5. Yes. It says extremely weak. So, and one and two are also like very weak and weak. Three, four, five, you go moderate. somewhat strong and strong. Six, eight, and nine have nothing next to them. That's the spacing you're talking about. Six has nothing. Seven is very strong. Ten is extremely strong or almost max. And then there's a dot, just as maximal, because some scales just go to 11. That's just how they work. Yes. And many times, if you look at the same Google search, what they did is they made that scale that was supposed to be exponential linear. Now all the spaces are the same. And that's a mistake because that should not be how you read that scale. And then you go back to what that reminds us, lactate. If you look at lactate curves when you do exercise from resting to maximum efforts, they have very similar behavior. Pain. Pain, if the pain is small, it's tolerable, it's fine. But if you cross a certain threshold, Just like the lactate threshold, it really hurts the pain and you cannot tolerate that pain so you go and take maybe a medicine or go to the hospital to treat that pain. So when you bring that to the exercise physiology world, it's very interesting because especially for efforts that are above your threshold like FTP or even lactate threshold like VO2 max intervals or efforts, intervals, very high-intensity intervals. They really hurt like pain. So if you are trying to, let's say, calibrate your brain or have a better sense of how you should use that scale in order to improve the communication with your coach, you have two options in this case. You can use the vocabulary that Borg added to the scale. like very intense or maximum, things like that. Or you can use pain to decide that because even if it's pain from exercise, many times that pain is similar to other pains you felt from an injury or a disease, like a muscle injury. Like the day before you get your root canal. Exactly. So if you relate that pain to the pain that you feel during it. VL2 Max Interval, which by the way all of my clients hate, then you have a better measurement to say, okay, that really hurt and I could hold that. Because why is that important? Because let's say you have a 30-second Wingate test, which is classic in the literature for testing anaerobic capacity, or you have a five-minute VL2 Max Interval. The pain is going to be different. The 30-second interval. It will hurt more. It has to hurt more. It has to be more painful compared to a five-minute, which is still going to be... Yeah, it's almost like the same pain, just distributed in a smaller amount of time. Exactly. So it's a higher concentration of pain. And as a sprinter, I know all about this. Even though it's free, yeah. So you can gauge that pain, or if you prefer to use that, to say, okay, I can hold that pain for 30 seconds, or you can hold that pain for... 5 minutes. It's usually easier to decide how much you can hold that. And then you can move on to the lower levels, like sweet spot intervals or threshold intervals, and then tempo and endurance. So I think it's really, really valid scale. And actually, he found that using the CR10 scale was a really smart move to other aspects, like different ages and different conditions. that he was trying to predict the F word. One point he mentioned on his papers that is really important is that the perception of the F word of the pain, of course, it's going to be different for each person. So I like, for example, on every prescription that I do for my athletes to add what I expect as a CR 10 value. And that's also on my article on training pigs. Perceive that effort or that pain the same way. So is that wrong? No. It's just part of being a human being. But you got to understand, and what I like to say, calibrate your brain, your perception to be consistent over time for an easy ride, endurance, and up to a sprint, maximum sprint. And people, and that's why, that's probably the number one reason of the article. gave the rationale how the scale was developed so people understand how things were integrated to come up with a scale. But after this point, it's up to you that you are reading the paper to, okay, that's how I see those levels of intensity and start to monitor them during the, again, VO2 intervals, sweet spot intervals. So you have a consistent because if that changed from one week to another, For the better or for the worse, now you have a very solid system. I like to say that there is no other sensor or computer more powerful than your brain to monitor those feelings. I've seen it in papers. It's called the master gland, which sounds grosser than it is. But it's also, you know... You actually brought up an interesting point, which I think goes under the heading of allostasis or allostatic load, which is, I guess, the easy way to put it is, if you anticipate stress, your body will prepare itself for stress. And so that's the basic concept of allostasis. But could you explain it in an easier way? way. I think I'm not good at this one. Maybe we should start with homeostasis. That's how you say it, right? Oh, yeah. Homeostasis. Yeah. I was like, homeostasis. Oh, yeah. Give me some hummus. That's like food, right? So the homeostasis is the state where your body is always searching for equilibrium. So whenever you complete a training session or workout or race, you had Stress, you generate inflammation, you've got to fix your body after that process. Inflammation being a positive here. Yeah. So you go back to your physiology state so you get ready for the next workout and that's homostasis. But at the same time, if your body is changing and adapting for bigger and bigger stressors, there's also this term, which is allostasis, where It's better prepared and it can be pathological or physiological. In our case, we expect it to be physiological and that's what happens as you train more and more and become with higher fitness levels. So physiological being a normal response to a normal load and pathological being like in response to a disease state, which actually I think it highlights something really fascinating about the body. because we kind of just hinted at it with inflammation is that a lot of the same processes that can be bad for us when we're sick are actually really, really good for us in response to like an exercise stressor because it's sort of like, you know, you can have, you've got 911 to rescue the kitten out of the tree but you've also got 911 if somebody like falls down the stairs and hurts themselves. Yes, and it's interesting because we have to keep balancing both processes over time. You've got to be in equilibrium, but also as a coach or as an athlete, you've got to give you enough training stress so you break that equilibrium enough that then allostasis happens and then you change your body, you improve your V2 max. You add more capillaries. You add more mitochondria to your muscle fibers. So that's allostasis because your body says, okay, this is stressful. I need to be better prepared. And you move on the scale. You become faster. You have a higher fitness level. And then you go back to allostasis. And that's really related to the third article that we will discuss later. Yeah. But I wanted to get somewhere else first with the RPE thing because Among subgroups, I think that there should be a subgroup that I'm a part of, which is middle-aged sprinters. And so, I think, because I remember, and this quite honestly keeps me up at night sometimes, and I'm like, fuck, I wish I hadn't have said that. Because way back in the day, when I did the podcast on how should you pace your endurance rides, I said, like, you should pace to a 4 to a 5 out of 10 RPE. Because at the time... That was how I was pacing my endurance rides. And not only that, I was telling people to pace theirs, and it seemed to work just fine. I have since learned that my RPE is actually a bit skewed. And I have a feeling it's because I'm a sprinter, and I'm extremely sensitive to my neural drive output. And so I feel like kind of at my LT1, I'm like, this is absolutely a four. but there's not a lot of space between like that and my threshold in terms of my RPE because it's not a lot of muscle mass increase and then like from there to sprinting I mean there's like there's a gulf of RPE in between and so I think that I what I'm getting at is that I had since learned I've said this on the podcast a couple times to try to correct the record because you know obviously If you are a scientifically minded person, as more evidence comes in, you're going to change your mind. This is absolutely something that I've learned a lot about, which is that everybody has a very different RPE scale. And so I think for some people, you know, their endurance pace is like a one. They're like, man, there's nothing here. I'm barely brushing the pedals. and it's like, you know, somebody with a 300-watt FTP, let's say, and their LT1's like around like 190 watts or something like that. At 200 watts, they're like, yeah, I'm doing something, I'm feeling this, all right, let's ride, this is great. And then at 180 watts, they're like, man, I am bored to shit. What is up with this? I'm barely brushing the pedals, like, where are they even? I can't even feel them, are they there? And so that's the kind of scale where I think that I've been flexible with and sort of meeting people where they are in terms of their RPE. And so that's just me. So where are you at in terms of, you know, like a coach or self-coached person needing to adjust their RPE scale in order to actually hit the same physiologic points? Because like if we take somebody's LT1, for some people it's going to be a one, and for me it's like a five. So the average might be a three, which would be cool. I mean, that's convenient, but like, not everybody's the average, right? True. And so there are several points, interesting points here that can be discussed. The first one is, I would say, again, doing the pain analogy, people may have a changing their perception of the pain over time. So there is also this aspect that are the CR 10 scale. or the perception of the scale may change over time. Myself, for example, I have noticed in the past few years that my pain tolerance is decreasing, which is not good, but it's what it is. And that may also apply for when you're using the CR-10 scale with someone that's 20, 30 years old compared to someone that's 40, 50, 60, may have a totally different threshold for pain. When you've got one foot in the grave, you're like, man, any more of this pain, I'm going to be lying in this box. Exactly. And that comes the second aspect, which is personality. You know, it's very common for cyclists, free athletes, and runners to have a really type A personality. And these people can overcome their perception of pain or the effort with something that says, okay, this is... Supposed to be helping me to be faster. So even if it's hurting two, I will go on a four or a five because it doesn't matter to me. I want to be faster. So you are tricking your brain to go on a higher intensity and then at the end, let's say you lie to yourself. Oh, I did a two and you know you are on a five. It's because you want to go faster. So we understand that. But then comes maybe the third point, which is testing. And that's why we do FTP tests every so, as it's recommended, every so 90 days at least. Yeah, 8, 12 weeks, something like that. Because maybe lactate testing or even the talk test. Because with those tests, you can cross-reference them. That's how I prefer to use the scales. I cross-reference the markers or the anchors from those tests, even a ramp test, if you prefer, whatever works better for you. But then you cross-test, cross-compare those results. And then there is a third aspect, a fourth aspect that you should take into consideration when using. the RP scale, the tests which then generate anchors, usually the first and the second thresholds, and then one that's very important that also leads to the third article, which is recovery from the workouts. So if you went on an endurance ride and it's taking longer than what's expected to recover from an endurance ride, something's wrong. It can be your diet. can be your sleep, but can also be the intensity of the workout, or it can be all together. Could be your children are coughing in your face, because it's that time of year, everybody's getting sick right now, everybody's actually been sick for like three months, so yeah. So that leads to communication. Why, how, so you reported RP of two or five, you have, we know we have this reference for intensity as anchors. And now we are looking at the recovery from that workout. If things are not matching as they are supposed to do, and that's my opinion when working with a coach can be really helpful because we have been seeing athletes and workouts recover for many years. So you learn how long it takes to recover from a VO2 session, from an endurance session. And if you know that's not matched to what it should be. Something's wrong. And then you go back to the athlete and say, hey, this is not right. Let's investigate. Let's discuss that. And hopefully with that discussion, you either improve your execution of the workout, be it intensity or perceived effort, or you improve sleep or whatever is making it not work as it should be. Yeah. That, we're now touching on your second article on feedback, right? And so, you know, you actually start out with the feedback loop. So with a coach, I think the feedback loop is pretty obvious. But why don't you take us through it just in case, you know, people are maybe not familiar with the feedback loop for coaching. Because I also know that some coaches out there, and I know it's a cost thing, so I'm not throwing shade, but like some coaches out there don't. Do as much contact with their clients as we do. And so, you know, if you are, you know, if you've got like a call with your coach like once a month or something like that, or like, you know, you got one email or something like that, like what should go in that? Or if you're working with us, like every single day, what's in your workout training peaks comments? And then let's talk about self-coach people. But first, let's go through that. Okay. So yeah, the feedback loop can be tackled. in the different ways. For example, I always tell my clients in the first intro call that every time they complete a workout, I ask them 24 to 48 work hours to go into TrainingPix and give them some feedback. Most of the time is 24 work hours, except the weekends when I am dedicating to my family and I will see on Monday. But if they have something urgent, I am available on the... My phone, so they can message me and ask for a change in the workout, for example. And besides that, every week we'll run an analysis of what went well in the previous seven days and what I think they should be done for the next seven, eight days. And so I usually send them like an audio note with that summary of the feedback from my perspective. I do not do this, by the way. Yeah, so I do that because, again, I'm trying to educate them to how I see their numbers, their workouts, and how I think it can be improved, but then I wait for their input. I always ask for their input. So how do you see it? What do you think was successful? What do you think could be better? And what's your availability for this week? And so with that information, a daily feedback. from each workout they complete. And also a summary on a weekly summary. We build that feedback loop in my case with my clients. And I wrote that article because many times when an athlete finishes a workout, they don't leave a, or maybe they just say, oh, it was good. What do you mean by that? It was good. I like to say I don't have a crystal ball. I need your input to help me make sense of the data. Data without context is many times meaningless. So we need that, what some people call in the computer science metadata, to add context to the power, heart rate. That's actually a great way to consider this because a lot of cycling people are complete data nerds. You need that metadata in order to have a full understanding of it because people are not algorithms. We are not just very simple bots where we see something on eBay and we click buy if it goes below a certain threshold. That's not what we do. And so I'm actually very much in the same boat. I just don't do the weekly summaries because I honestly wouldn't know how to summarize somebody's week. But, you know, I mean, all of us at Empirical Cycling, we do the same thing. It's like, you know, some of us do it more in text, some of us do it more in the training piece comments, which is where I usually live, like, a lot. And so, like, so my clients know that, you know, they read the next week, and they're like, hey, what's this about? What's that? They'll ask questions, like, you know, or they'll leave feedback in their, you know, the day, and it's like, this sucked, what do I do tomorrow? And I'll be like, ugh. Maybe you should rest tomorrow. Or it's like, oh, this looks good. You know, just, you know, is sleep okay? Did you eat everything today? You know, that kind of stuff. And like, that's, I think, probably undervalued in terms of when you get a coach. I mean, because like, you, you more than I do, but you work with a lot of, like a lot of C-suite people. You work with people who've... you know a lot of very stressed parents people with very busy jobs people with really demanding travel schedules and you do a great job working with them on making last minute adjustments or figuring out what's the right approach and like maybe this is the wrong approach let's try this next time and and I think that that more than the workouts themselves makes a bigger difference when you go get a coach I think I mean, not to try to sell us or anything like that. Just the concept of having a coach, I think, is like that kind of feedback and that experience is, I think, underrated versus like what the workouts are. Yeah. Another reason that was a strong force to write this article is, and I always share that on my intro calls too, is my most successful clients are the best communicators. The ones that really take the time to sit and write, or even, I mean, if you send me a note on... And you don't have to, it doesn't have to be like a... No. You don't have to write Don Quixote or anything every day. But if you don't take the time, and maybe you send me the note on my phone, for example, as a message, I said, that's not ideal. Ideally, that note should be, that metadata should be on TrainingPeaks where the... Objective data is. The file, yeah. Because then you are building history over time for objective data and qualitative data. So when you go back and look at it later. Exactly. You find gold because this information really helps us. And if you ask data scientists, probably the number one reason why most data science projects fail. is lack of context. So even if we were algorithms, even if you look at several attempts people did to use like AI for coaching, you know how often they fail because even if you have all the power, heart rate, all the objective data, if you don't have the subjective data, which is really hard to capture from even on site or remotely. that data, it's not enough to give you, to feed the algorithm and to give you the best next workout. So going back to the, to that best communicators story, I said, but what makes a best communicator? What are, what's the information that I need as a coach to have, to show my, my client or my athlete and say, please. That's one of the questions I actually had is because the first time I read this article, like you didn't send it to me beforehand, like they hit publish and I read it and I was like, and you know, I usually just kind of skip down to the bean and potatoes and stuff and I'm like, okay, you've got sections for nutrition and hydration, environment, equipment, and like, and this is, and I was, in a way, I was like, where's the part where you talk about like, where I say how hard this workout was. But I think that you are actually highlighting something which is even more important, which is the more holistic view of all the factors. that can affect performance and RPE on the day. Like everything that your master gland will integrate. True. And you don't have to write all of that workout feedback because it's going to be like a long test for everybody. 364 days of no equipment changes. But if you can maybe pinpoint three of those topics that changed or were significantly different for that day, That's really valid for us as a coach. For example, you know, I track the device's ID my athletes use on their workouts because you can get that information from a feed file. And then it's not uncommon to say, well, that's a different device, a different power meter. Did you get a new? Oh, I got a new bike. I said, oh, really? So now you have a new bike and new equipment and that may change how... the biomechanics, the adaptations, all that's related to the quality of that workout. Oh, I started having back pain a month ago. Oh, what happened a month ago? Oh, you changed your bike. Now we are tracking that. So maybe you need a bike fit. So let's check that. And that's some of the information. So I recommend checking out the article and look at, I know it's a lot. But as you said, well, all those aspects can affect RPE, which is the odd article, and also give your coach a lot of information on how things are changing. Or maybe another good example, I had a terrible night of sleep, and then it was what I like to call like a key workout, which may be high-intensity efforts or intervals. Is it wise to do that effort that day? Probably not. Better maybe go easy. recover, wait for another good sleep, and then go for the high-intensity workouts. But if you forget about that and you try to complete the workout and you fail because you are not fully recovered from a bad night of sleep or maybe a few bad nights of sleep, how do I know that what the problem is sleep or maybe not nutrition or too much workouts or too many workouts? All this has to be integrated. And this is not easy to capture just with power and heart rate, for example. Yeah, very true. And I think that keeping that context in mind, and also not only that, I think that's the other benefit of a coach is anticipating things being really stressful for people. So I think for my clients where I know if at a certain time of year, it's... probably going to be off the rails more often than it's on the rails. I'm more likely to be like, all right, let's bang some harder training earlier when you're feeling good. Like, even if it's like a weirdly early time in the season, like I've had so many people doing some fairly intense, not, you know, going gangbusters or anything like that, but some fairly intense workouts as early as like November or December sometimes, even if we just kind of start sneaking up into those kinds of ranges. And sometimes I'll get the comment, oh, this is pretty early for this stuff. And I'm like, well, I saw what happened. Last February. And if this year is going to be anything similar, we're going to need this training now, so that way we're not like scrambling once the warmer weather hits in March and everything starts to settle down for you. Yeah, I think winter, especially in the northern hemisphere, is really a good example where things change dramatically for being forced indoors, cold. And you've lived in Ohio, you know exactly what this is like. Exactly. And I was spoiled to live in Brazil because our winter here is like your fall. And then I like to say that here is like just warm and very hot. There's no other season. And so for me as a coach being from Brazil, but lived in Ohio, of course, it was the second time that to live there two times, but it's easier to understand the restrictions and how hard. a few hours per day with sunlight, all of that affecting your willingness to jump on a bike and go hard for an hour, two hours, and then five, six times per week, and then communication. We need to, me as a coach, especially, I think winter is very critical, that kind of communication, because then when you start racing, it's a different communication, but for training itself, winter is really sensitive in terms of recovery. It seems like, for example, the recovery rate's always low down, so you need more time to recover, less intensity. But everyone is different. Some tolerate well indoors. They do fine. They go indoor workouts four, five, six hours, and they're fine, even if it takes longer for them to recover compared to... I know that sounds insane for probably half of our listeners, but like... For real, like we've got clients who can do like, you know, four or five, six or even longer hours on a trainer and they're happy as a clam. You know, it works for them. So that's great. But if it's not, you know, if that's not you, it doesn't mean you have to do that. But, you know, again, that's like, you know, the whole individualizing thing. But yeah, sorry, continue. Yeah, that's what I was saying. Yeah, I still don't believe some people do that, but some do. And even for them, I noticed it's very frequent that they need more time to recover from that session. The strain is much higher, as they like to say. So you need more blood being diverted to the skin because the time of regulation, the ability to keep you cool down is harder on a trainer. So because of that, when you finish a workout. You are more tired. You need more time to go back to the homeostasis. And again, sometimes you learn that the hard time when the athletes get injured or get sick. And if we had better communication before, better workout feedback, we would have adapted the workouts, give more time in between sessions and avoided that for a successful winter training. Yeah, I've actually had a couple clients where in the winter, they actually go quiet. And a lot of the time, it's because, I'd say 50% of the time, it's because work stress ramps up in the winter. And half of the time, it's just straight up seasonal depression. Especially if people kind of live in New England, Minnesota, or even into Canada, the winter, the days are short. UK even. Days are short, not a lot of sunlight, a lot of rain or snow, cold. And when somebody goes quiet, especially if I'm expecting it, I'm like, oh, here we go again. And you can only needle somebody to give you workout feedback so much. And I've had clients where they'll just keep doing the workouts, but I read the subtext of, This person's not really in a good spot right now. We're going to avoid all the high-intensity training and when things start kind of getting back to normal in the spring, all right, then we're going to ramp things up, especially as we get closer to racing. But like, yeah, that's a whole other aspect of the context that I think really warrants like a good look and some honesty from people. Because I think especially if folks are self-coached and in the winter you feel that motivation starting to wane. You know, it's, I don't know, where would you go with that one? Like, what advice would you give to people in this context? My number one advice is consistency. I think at that, during that time of the year, it should be your number one priority, just jumping on the trainer and riding for consistency. There is, because we know long term, that's very important for performance. consistency on the bike, the intensity every so often, depending on, again, on how you are recovering. Keep it fun, I would say. Listen to a podcast, watch Netflix. Some people like to go into Zwift races. You've got to be careful. If you do it too much, it might become a problem. You don't want to do it every day. Yeah. And they are like... threshold races all the time. Yeah, well, it depends on where you're at versus the rest of the field, but yeah, sometimes it can be that. Sometimes for some people it's like, you know, a pretty normal looking race, a little more on the gas than usual, a lot less coasting, but other than that, like, yeah, oftentimes they're very, very hard. Yeah, and of course all people tend to go on the... upper level instead of going with their level. So it just makes it even harder. But we understand. No weight doping on Zwift, folks. It makes it harder. But that's how I tackle it. But I understand. It is depressing to be forced on trainer for so long, so many weeks. And of course, we're going to go faster and longer. But there are limits. And these limits are much stricter. when it's cold outside and you are forced indoors. So keep it fun, keep it consistent, and that should be enough for maybe not the desired adaptations we want at that time of the year, but it's better than not training at all or getting sick or getting an injury. Yeah, what's that phrase? It's the dream of a perfect plan is the enemy of a good plan. Yes. Yeah. Speaking of that, moving on to the third article, I wanted to ask you about RPE and adaptation. Because in, oh God, it was one or two podcasts ago, Rory and I did practical proxies for stimulus. And I think that part of that, or it was maybe an earlier podcast, God, I can't remember at this point, there's been so many damn podcasts. talked about how something can feel harder, but that doesn't make it more effective. So what's the balance point between RPE and actually getting a good stimulus? I mean, especially when we're considering the enemy of a blah, blah, blah. That's a really good question and complex answer because Well, that's why you're here. You're smarter than me. You take this. I may start with, it depends. But anyway, again, I like to go back to the basics. I like to go back to, for example, if you are using RPE for indoor on trainer sessions, ideally, you should do a round of testing for indoors, just train on the trainer, and get more Aligned Perceptions with Indoor Riding, and then use that to guide you, for example, through winter, because that's going to be the best or the more specific perception you can get for the kinds of workouts and intervals that you are going to be completing or executing while training on a trainer. Once you are, let's say it's spring, Time to go outdoors. The best thing you can do, again, is to recalibrate those. And then going back to the basics is complete another round of testing. Again, find out what works better for you, but you've got to make sure you've got some good short efforts and some good long efforts. Actually, you have a really good article on TrainingPeaks about FTP testing, and I follow that with my clients, although most people don't like because it's too long for a FTP test. But in my experience, it really works well to avoid overestimating the FTP. And, you know, both ways can go wrong when looking at RPE and the intensity, which is either under-training or over-training. You've got to be as much as accurate as possible to be training at the right intensity and get... I know there is no division, it's a continuum on the intensity domain. But there are some metabolic or muscle fiber adaptations that are expected to happen depending on the intensity and the duration and the frequency of the workouts you are doing. And because of that, if you every so often complete the testing to make sure that you are doing it at the right intensity for that expected adaptation, that's the best approach for it. Because if you do that, then when you go into a session and something does not align well with what's expected, it's the opportunity to, again, investigate what might be affecting you. Is it, again, a new bike or bad nutrition, bad nights of sleep or maybe too much training or not enough training? So these aspects must be always integrated. And when I say I like to go to the basics, because I think at least with the tools we have right now, we need max efforts to define those anchors in a more definitive way and also track how they are changing over time. Hopefully one day we will derive those from sub-max efforts, but right now we don't have really good tools. So you mean performance testing? Yeah, performance testing. And so for us using WKO5, I mean the model... doesn't extrapolate from submax efforts any kind of potential max efforts. And so it's like you've got to, you know, if you don't have the right data for the model, which is just max efforts, like what is your true capability, you know, the metrics that are built on the model aren't very useful. Exactly. I was trying to, not being too technical, but that's the technical. I think people understand. This is our audience, we get it. All right. Everybody knows. So that's exactly what I recommend. 8 to 12 weeks. Make sure you have accurate metrics. If the environment is going to affect you a lot, maybe altitude, hot and human environment, or indoor training, if you can and if you prefer to be accurate, which I think you do, do the testing. Make sure you have a well-fed model if you are training with data to cross-check that with your RP, because you need that validation. And if you look at the human body, most of our systems, they have redundancy. They don't operate on a single master system. They always have redundancy, because if one fails, the other one can, okay, this is failing, let's adjust. And that's how I approach training. I think we should have several systems to cross-check. how the workouts are being completed. One is with data, power, heart rate, whatever you collect. The other one is RPE. Look at the scale, understand how the scale works, and make sure you apply that to make context, to give context to the data. And the third one is your perception. You have, again, the master gland. Make sure when you complete the workout, that if it's an easy workout, you feel like, oh, it was an easy workout. Oh, if it's supposed to be hard, it's hard. Also understand, am I recovering before that workout enough to be fresh for that key workout? So all of those redundancies really work well. And then you add maybe a fourth element, which is the coach, because the coach brings all long-term experience to the process to help you speed up. or maybe make it more accurate, even more accurate. Okay, this doesn't make sense. I remember, there's a funny story, when I was doing bike fit a long time ago, one of my clients arrived and I liked to use his FTP, if they knew what was his FTP, and that was like almost 15 years ago, to guide the effort on the... I see where this is going. ...on the bike fit. And then the guy says... tells me, oh, my FTP is 400 watts. So I look at the guy and said, no, you don't have 400 watts as a FTP, but I trust him. And then, okay, at the time we used Compu Trainers were really hard to calibrate. Many people didn't know how to do it properly. So I calibrated the Compu Trainer, the guy jumped on the bike. Okay, now we are going to do a threshold effort at 400 watts. You know what happened. He was not able to move the cranks because it was way too hard. So what happened is the other guy that did a physical performance testing on him, a VO2 max that's using gas analysis and a compo trainer to guide the work didn't know how to calibrate the compo trainer. So he got much higher numbers and he believed that he had a 400 watts FTP. So what's the moral? The moral is if the The other guy knew what he was doing enough. He knew that guy didn't have a 400-watt FTP. So how do we apply that to our day-to-day work? If you see that number coming from a power meter, you got to tell your client, your power meter is miscalibrated, it's not working. Or hopefully it is. Or maybe, yeah, you became Superman. Now you're ready to fall to the France. Actually, I just ran into this with one of our clients. One of our coaches and I were messaging the other day, and we were looking at one of their clients who had gained what is essentially like 80 watts over the course of like two months. And in some ways, I mean, in some ways it looked reasonable when you looked at some of the summary metrics. and then when you kind of look at, you dig into the files, you look at the timeline, it's like, oh, this didn't actually happen. Like this power meter got a little weird and then now it's like, you know, then you start training again and it's like, oh no, it's like you think you've lost a ton of watts when actually you haven't and things have actually been fine. It's, yeah, it's really weird. I mean, measurement error is one of the, I would say, more common issues that a lot of people face. I think as long as the like if that guy had kept using that other CompuTrainer and you know and figuring his FTP was 400 watts as long as that thing like was consistent with itself like okay yeah no problem but as soon as you go up against somebody with an actual 400 watt FTP it's like oh how come he's dropping me so hard we weigh the same we've got the same threshold it's like well you some of your assumptions were is unfortunately incorrect until when you get a really good comparison across. All right, now you can blah, blah, blah. Anyway, so I actually also remember one of... Nah, maybe we shouldn't talk about this on the podcast. You know exactly what I'm going to talk about. All right, so we'll just share that, you and me. But anyway, so when it comes to adaptation and... RPE. And because I'm looking at this article and it's like, I think probably the bottom of the article is a lot of the times where people should, I mean, it's sort of like reading the conclusion in a paper. You know what I mean? Yes. It's like you go to the bottom of it and you read, what does this person suggest I should do? Or what does this person conclude from the data? But without seeing the data yourself. So what's the data you shared in this article and how, and what were your conclusions based on the data? You meant the one on the muscle adaptations, right? Yeah. Yeah, that article is actually really interesting for... It's got great graphics on it, by the way. For practical purposes, because we always talk with our clients, you need to higher volumes, more endurance, more intensity. But how do we pick up which one is the best? And that paper, it's a systematic review, so it looks at many other papers that did a similar analysis and they try to summarize a bigger number of subjects doing similar stuff to have stronger evidence about what works and what doesn't work. And as we know and expected at the end, Everything works. Endurance riding, high-intense workouts, and they divide into endurance, high-intense work intervals or training, and sprint training for three categories. And what they found is we have evidence that all of them works. And we know that. So that's why we have sprinters, we have trim trellis, and we have several specializations in cycling. But then came... I think probably the biggest conclusion is when you are training to be a faster cyclist, what order or how should I do it? And how do I compare as maybe an average rider to pros, things like that, my training, my time available? And that's where it gets complex because With the current technology that we have for sensors, for example, you are not going to be doing muscle biopsies on your athletes to see how their muscle fibers are changing on a weekly basis. And also, you don't want unqualified people taking biopsies anyway. Exactly. Have you seen those pictures of necrosis over the muscle? It's gnarly. No, I haven't. You know the scar on the back of the hand from Fight Club? It looks like that, but worse. So, yeah, you don't want that with your clients. But we want to know how the muscle fibers, I mean, there are, of course, there are several systems in our body that adapt or overtraining, but let's say for this case, the muscle fibers are the most important and we need, how do we know how they are adapting or reacting or going back to the allostasis process, how they are changing so they can offer you more ATP, which is your energy? Currency when you are exercising. We have very limited. Right now we have the most powerful, the two most powerful ways to know that maybe three is your power output because that's the output of all the systems being integrated and then telling you how much power you can deliver to your bike and ride your bike faster or not. And then maybe your brain. It's really easy to know. When you are training over weeks, you perceive that you are going faster because you see the average speed increasing. And then maybe come the third one, which is Strava comms, when people, you know, if you are getting PRs, you are improving. I mean, at least you expect that your muscle is getting better at delivering that power. But that's just the output. And then when you think on the input, you need, again, you go back. to Endurance Training, Sweet Spot Training, Threshold, VO2s. Which one of those is the best for you? And how do the muscle fibers, the mitochondria, the capillaries adapt around that? We don't have a good tool to tell you the answer. So that's why when you think about coaching, we still have a lot of art and empirical training. because there is no way to measure that. The way we measure that is what we just discussed. You go every 8 to 12 weeks, do a new round of performance tests, or maybe you go try on a Strava segment, or you go into a race and compare that performance to the previous year, if you have data on the previous years. But that's still very limited on how you can judge. What kind of workout made you faster or didn't make you faster or made you slower? And then, so going back to the article, the article really shows, okay, everything makes you faster, but it doesn't answer the question, how much or how often? And especially, which is another limitation of most exercise physiology articles, most are short-term. Mostly are like 12, 8 weeks and lower. But you know, we have clients that we are working for years. And then when you are working for years, what's the best combination of VU2 blocks, threshold blocks, endurance block, base blocks? Or do they need a block at all? Exactly. Maybe they could be just like a linear progression forever. But we need that answer because that's what coaches are supposed to deliver. Of course, we have a really good experience over time working with several clients. So you know what works better over time for each kind of physiology. But you need, as I always like to say, there is a steep learning, especially as we... Start working with a new athlete, you have to understand how his physiology works, and that takes time, takes some rounds of testing, some rounds of block training, but then you are building that history, and that history helps you over time to fine-tune the training blocks or the prioritization even more for that athlete, and they keep progressing. And then comes the second part of the article, which is the plateaus. So it's well known for many people that if you do maybe, let's say, threshold blocks for four, eight, 12 weeks, at some point, they will not progress anymore. So how do you handle that? And that's another area where the article doesn't have like... I was about to say, are you asking me? I thought you wrote about this. So the article also doesn't provide the perfect answer or the best answer. Because if we had that answer, I'm sure AI systems would be dominating the coaching business. Well, I mean, they're only as good as the data that they're trained on, right? And I actually think that the, because by the way, the meta that you're referring to, well, like in the show notes, this is not the one that Jem did, that he was on the podcast last time. That found pretty much the same thing, but looking at training intensity distribution. in terms of VO2 max and time trial performance from like 5 to like 60 minutes. And this one was looking at more the specific physiological adaptations like mitochondrial density, like what is like citrate synthase activity probably as the mitochondrial content marker, and like capillary density information, things like that. So it took a very different tack approaching the same problem. Like what are the... physiologic adaptations that we see associated with endurance performance and adaptation, and what's the training that seems to elicit them best. And, you know, if I recall correctly, they had, just like in the meta that Jim was on, they had a subgroup analysis on highly trained people and sprint interval training. seemed to be more effective in improving some of those metrics than others. Just kind of going back to the same point that, you know, when you talk about plateaus, this is what a study typically, like, what, four weeks is not going to show you. It's like, how do you go through the plateau? Because the context of all of these studies is like, a lot of the times these folks are just coming in from the off-season. You know, they've done kind of moderate intensity or they're not even controlling. all the writing or training that somebody's doing outside of the lab. And so there's a lot of, what would you call this, moderating factors that really could influence the potential interpretation. But when we put all of them together, we kind of wash those effects out and we're looking at what is the fundamental takeaway of all this. It's like, as you get more trained, you have to train harder. And this is a question I've gotten a couple times recently is, in various forms or other is basically like, the subtext is, I don't want to do VO2max training. It's too hard. Maybe I'm not up for it right now. Maybe there's some reason. I'm not judging anybody who doesn't want to do it. It's fucking hard work. And thankfully, I think past my days of doing it too. I'm grateful for that. But, you know, it's like, what? You know, in what way could I possibly increase my training stimulus to keep getting my threshold up? Or even sometimes the question is like, what evidence do we have that we need to raise VO2 max to raise threshold? You know, and this is, I think, one of the downsides of how reductionist the literature has to be put up by necessity. You know, like you, there's no, you know, like four-year longitudinal cohort study. that's looking at, you know, any kind of like, what's it called? Like intervention by time interaction, or sorry, treatment by time interaction. It's like, you know, you're not going to find that. And I did a calculation the other day where I was like, all right, if I'm working with somebody and let's say they're like development athlete, they've got a 300-wide FTP. And over the course of a half-year build, I'm going to want to see maybe 10, 15, up to 30 watts of FTP improvement. Over the course of a typical study of four weeks, if we break that out, we're going to be looking at five watts or something like that for a four-week study. And on a 300-watt FTP, that's like 2%. And that's right on the money where GemsMeta found Like, okay, you know, we estimate a 2% improvement for VO2max for highly trained people doing high-intensity training, basically, like polarized. And, you know, the fundamental point there is like, if you're well-trained, you got to go harder. But what's not in the article is what's the cost of that? What's the allostatic load that you are facing doing a ton of VO2max intervals in the course of like three, four weeks? And, you know, there's... I mean, there might be one like on the margin somewhere, but I haven't seen it. That's like, what's the fatigue after you do something like that? How long does it take to recover? And that's kind of where the art of coaching comes in. Sorry, that was a lot, but your thoughts, please. And that's true. It's very clear as the athlete becomes more well-trained, the harder and maybe the longer both they have to go. We tend to go more into the polarized training because as you go harder, you need more time to recover. But at the same time, you're going longer. So there is also less few hours to recover after each training session. And that's, as you said, well, that's when it becomes really tricky. That's also when I think metrics like that can also help HRV. Tracking can help you decide when to go hard again because it becomes less obvious when you are ready for the next big workout. And because when you are in the beginning or... Actually, yeah, dig into that a little bit because I've... I've been on record many times as being an HRV skeptic, but there are edge cases where I think it works really well. And I mean, I think that this is something that we've both seen in practice. And so, yeah, why don't you talk about one of these edge cases? Because I think a lot of people are like, HRV good, bad equals should I train today? And there have been several studies on that, and there's really not much there. in that kind of utilization. And not only that, I mean, you and I, we both worked with HRV as a metric before, and it's really noisy. Yes, and there are some interesting aspects about it. And for example, one of my clients last year, he completed a Vue 2 blog doing doubles, and we were tracking HRV, and it was beautiful. Because you could see... The drop in HRV, and you know, the lower HRV, the more fatigue. So we could see after a double day, a big drop in HRV. A recover day, he would recover a bit and then drop again, depending on the frequency of the doubles. But we did that for three weeks. And it was very clear from the beginning, he has a high HRV reading to the last, to the end of the third week. He was stressed. His body was struggling to recover. And by chance, we had to postpone the recover week by one week because he had a trip. So what we did instead... The trip was like a high-volume kind of cycling vacation thing, right? No, it was going to be like a low-volume for the recover week. And he's on average between 12... and 15 hours per week. So what we did, we just, we did just an endurance week. And then on that endurance week, there was like a linear relationship, the HRV was recovering. So he was going less intense, he was recovering, but not as fast as... So it was like 12 hours of like endurance riding that week? Yes. Okay. And then after that, he went on a trip and we switched to easy ride, really easy on hour rides, very low IF. and then the slope of the trend increased even more. So you see how people tend to think it's the same? It's different. Endurance, the slope is there, it's lower compared to VO2, but easy, the slope of recovery is even higher. So that was the example from last year, outdoors. Did you send me that with like highlighting like... VO2s, endurance, and recovery? Because I want to put that in the show notes. Yes, I will. So this year, we did the same. Again, because, you know, there is not a lot you can reinvent in terms of workouts, but it was a good time for a VO2 block. But this time, it was indoors. And after two weeks, he got a very strong viral infection, the gut. very bad diarrhea problems. Classic norovirus, right? Yes. It's going around, yeah. So why it was different? When we looked over the HRV analysis, for some reason, probably because of the longer recovery in the indoor rides, he was not having that small recovery in the HRV after each double day. when doing indoors. So the depression or the stress, although if we look at just the rides, they were very similar, including power, it was much harder for him to recover. And that's probably the reason why he got sick. And we had to stop the block at two weeks. Now he's well recovered, already going fast and strong after just a few days. But that's what I wanted to point out. That's when you get well-trained, he's well-trained, very consistent rider, you got to start pushing even harder. But when you start pushing even harder, that's when I think metrics like HRV make more sense because they become more sensitive. When you are just juggling around with one or two intense workouts here and there, It drops, of course, after the intense day, but you have enough day, enough time to recover and be ready for the next session. So that's when it becomes another, which is good. You become, you see that trend that you go for a strong workout, it drops, but then you rest, you recover, it goes up, you tackle again, you go hard again, and then drops. But that's the, let's say, the healthy situation for HRV. I've seen a couple instances of HRV doing actually the exact opposite, where the more somebody trains, the better their HRV gets. That's how it should be. But then when they do a recovery ride, their HRV tanks. It's like literally the mirror opposite of what you would expect for day-to-day HRV readings. And actually, this is one of the reasons that I think that... I've been an HRV skeptic is because for somebody like me, like if I started to train right now, like my HRV would improve rapidly with my training. But for people who are already really well trained, I think what you're highlighting here is that HRV is potentially very useful for reflecting off-bike stress that may actually be hard to detect because I've got a couple of clients who still love their HRV. and they mostly use it as an early warning system for their like oh my HRV is in the tank but I feel fine I think I might be getting sick and that usually happens you know in the context of like January, February, March up here in the northern hemisphere. Well in my experience so far of course I agree with what you said and I think at least my experience that HRV is more valid more useful when there are very high Loads of Stress. Be it on the bike, be it on the life, not just, or maybe both. Be it five glasses of wine. Yeah, that, you know, that's probably the number one reason why your HIV drops more than being sick is alcohol intake. And so, but again, you see there, but that's what you're trying to do when someone is well-trained. You are trying to push it even harder. So at that point, The stress from the training, as you said well, is really high. And then when that stress is really high and very frequent, that's when I think we've got to keep an eye on HRV, especially the trends, like a three-, four-day trend, a week trend. You can see that very clearly. The person is not recovering. You need to give a break for them. Otherwise, he will get sick. Where is the limit that we cannot answer? We don't have an answer from HRV. We know that it's going bad, but the threshold, let's say like this, it's still a work in progress. But when there is a lot of stress, training stress, life stressors, it really shows up on HRV in my experience. As you said, when it's a recovery week, maybe it's not so useful, except if the person is going through a lot of life stress, then it's a different case. But it's supposed to be maybe random. But when you really apply stress, it really responds with a high sympathetic activity. And that high sympathetic activity really neutralizes the parasympathetic. And then you see that drop very clearly. Sympathetic being fight or flight and the parasympathetic being the like, hey, let's rest and digest. Exactly. So maybe it's more sensitive to stress, not to recovery. Useful to give you a sense, but I, for example, it's not uncommon to have people that do like back-to-back workouts, even if it dropped the HRV, doesn't mean you are not ready for the next workout, but you got to keep an eye because if it drops and stays there, or if, like you said, if HRA, resting heart rate goes up and stays there for a while, then it's a trend and that's a problem. But that natural variation. Potentially, yeah. Actually, I, oh yeah, I think that's actually maybe one of the things that bugs me about HRV is that people over-index on it. Yes. It's, you know, unless it's like, and I think also considering the noise of the measurement that we mentioned earlier, because like your Apple watch, your Garmin watch is using infrared, Spectroscopy in your wrist to look at your pulse. And, you know, like looking at, was it total hemoglobin? I think it'll watch. And so like, that's a noisy measurement. This is not an EKG or ECG. So you've, so I think in that context, or even as you're saying, if somebody's, you know, if you've got like back-to-back days and your HRV is like not where you would like it to be, it's like, okay, maybe I'm not fully recovered, but like, Does that matter right now? So like if we're trying to increase training load, maybe that's kind of the point? And that's exactly what linked to what we are discussing. Many times, especially with well-trained athletes, you need that. You need to really punch the system so it hurts and then you give a break and then you recover and you get stronger. But as you get stronger and more well-trained, the punch is going to be harder and harder. Of course, without being sick or injured. Because if you don't do that, homeostasis wins and you don't progress as an athlete. You always be like on the plateau. No, dig into that. What do you mean homeostasis wins? Because I know what you mean, but I think that deserves some expansion. It means that the training stimulus or the training stress wasn't enough to disturb enough the homeostasis and get to allostasis. So, of course, you'll be tired, but the recovery process will not be enough to make you stronger or faster. And that's homeostasis. You just gave a stress and you recovered. Homeostasis means you adapt. You became different when you got recovered from that stress. That's very easy to happen when you are untrained in the first weeks of training if you are out of the couch. But as you get more well-trained, that becomes much harder. And then comes another problem, which is your ability to recover. It's very sharp, the difference. Some athletes do recover really faster. Others take more time. And that's, again, how you can link that to... Resting Heart Rate, or maybe HRV analysis, because then you can have a better sense, at least remotely, if your athlete's not giving you the best communication from what's going on with his recovery, and then adapt for that. Yeah, and hopefully not over-indexing on it. I mean, it's just one piece of many. But actually, I wanted to, speaking of subgroups, because we were just kind of talking about well-trained people. which I think is probably the majority of the people listening to this. But also in the meta-analysis, there were additional subgroup analyses done. So I think it's interesting to note that mitochondrial content increases similarly with endurance training, high-intensity training, sprint interval training, but they're not significantly influenced by age, sex, menopause, or disease. And I think that a lot of people might find that a surprising result, but it actually kind of confirms everything else that I've ever seen in the literature, especially when done on a kind of whole-level analysis rather than just like a single study, because we can, you know, we don't have to talk about like sampling variants or anything like that, but, you know. Precisely. And it's actually very encouraging because you get all that years of research and years of subjects being volunteers, and then you have a really solid evidence that no matter your age, your disease status, if you exercise consistently, if you start training, the adaptations you get if you are looking for health, they will happen. And if you look at the article on Training Peaks, one of the references is a paper that I co-offered, and it was done in one of the biggest cardiac rehab hospitals in Brazil, and that we showed exactly that. We are able, through exercise, strength training, and endurance training, able to change the NEHA, New York Health Association. It's a classification for heart failure. patients from Level 2, which is still mild, but we moved them to Level 1, which is great, that improved their quality of life, their ability to complete activities, daily activities, and with a simple pill, exercise. Unfortunately, we don't have, yeah, there's no such thing as exercise and a pill. I still love that old, maybe it's not that old at this point, but that Glenn McConnell article titled Exercise is the Real Thing with an exclamation point. In a peer-reviewed journal article, there's an exclamation point in the title, which I just love so much. But I think that you're right that it's actually really encouraging because I think in a lot of ways, from first principles, it makes a ton of sense that a muscle is going to react like a muscle. Unless somebody has got a horrible kidney disease or cancer or something like that, their cardiometabolic adaptations like VO2max, it's going to react pretty much the same way as somebody else. And there's going to be a kind of diverse range of what's the rate and magnitude of adaptation. But it's actually, I think, really... encouraging to know that like the same stimulus applies for everybody. It's not like, you know, it's not like there's going to be somebody out there who's going to really, who's like at like a 95 VO2 max and they're going to get to like 105 by just tweaking this like little bit of training here and there or something like that or even if you're just kind of stuck at 40. Can you increase it to 50 or 60 by making one tiny little tweak? It's probably not going to happen. But by hammering away at the basics and making sure your recovery is in order, that, I think, is what we're saying is probably the much greater impact on subsequent adaptations to the training rather than you've got to find the silver bullet for you. Yes. One of the, you know, VO2 max is probably one of the best markers that you, that tells you how much you're going to live. So, health-wise. Depending on how you read the literature, like strength is also up there too, so. Yeah, both. Yeah, I think thighs do save lives. But what I mean is, if you can exercise and you can get those adaptations, it's, I mean, don't, don't think twice, just do it because it's, I mean. I remember one of my strongest riders ever, when he started with me, he was on the bike fit, and he was overweight, not trained at all, and because of the bike fit, he decided to start and try, and he got incredibly strong, because, as you said, adaptations are universal, and he was able to... have his genetic background work and get fast and he won several races and went really happy about it because he tried. So that's very solid evidence for that in this systematic review that they showed us. Yeah, and I think that that's probably one of the more fundamental learnings because I think a lot of the time people want a just what the fuck do I do? lesson out of the scientific literature. Kyle and Rory and I did a podcast on this, I think late last year, on what we can and cannot actually take away from the scientific literature. One of my overarching points that I tried to get across was that you're never going to get told this is what you should do. It's like this exact protocol, a lot of the time in I mean, you've done research. A lot of the protocols you do are for convenience, and it's not necessarily because they're ecologically valid. It's not like this is exactly how people train in the real world. But in some cases, if you're working with cardiac patients, maybe everybody should do just 30 minutes walking on the treadmill to start without having to get too... nitty-gritty about it. And I think that learning the fundamental principles of adaptation signaling and recovery is probably the bigger, more broad lesson to learn. And it's a harder lesson to learn, I think, too, when you read the literature, because I think that there's even some folks out there, and I certainly used to be one of them, where you want the literature to give you something that's actually not there. True. And even on that study that I mentioned on the cardiac rehab, we did intervals, high-intense intervals, which people are afraid. And these people were like, they had a past history of heart attacks or bypasses, and they can do it. So it doesn't have just... To be, of course, got to have a clear from your doctor to do it because there are several cases in different levels. I don't want to cause more problems than you already have. But if you, you can do like a ramp test and see where your heart may start to show like signs of ischemia or insufficient blood going to the heart in late terms. And with that, you You have a threshold. And what we also showed is that with endurance and interval training and strength training, we are able to increase that threshold so that person can now, even if they have a past history of a heart attack or bypass, coronary bypass, you can still train and increase your threshold so you can reach higher intensity without being deficient on the blood flow to your heart. And we should also note that despite that you are a doctor, this is not medical advice. Please talk to your doctor if you are one of these folks before you undertake any strenuous exercise program. And actually, that's one of the things I've done recently is I've started making sure that people have medical clearance for this kind of stuff because we have certainly worked with people who have had heart attacks and all that kind of stuff. Are you clear for exercise? Are you clear for intense exercise? What are the guidelines? What do we need to know from your doctor? I add to your fibrillation, which is also very common in endurance athletes. Yeah, unfortunately. And actually, speaking of which, I actually wanted to kind of go a little off script because we brought this up and we've never really talked about it on the podcast before, but in terms of like health and VO2 max and all that kind of stuff, like my reading of the health literature. I'm far from an expert. I am a dilettante at best with this stuff. But it seems to me, so please correct me if I'm wrong, that the way cyclists train is like above and beyond all recommendations for best health outcomes. Yeah, there's a classic J-curve that they mention that I don't know if you heard about it before, which is you are sedentary. You start to train and you relate the amount of training with the sickness you get. So morbidities. Yeah, morbidities. So what they see is you start training, you add more volume, more, let's say, hours per week and maybe some intensity. Strength training is also really important. And then you move on the J to the bottom of the J. And then there is the lowest level of morbidities and health problem. So it's the best bang for the buck. Exactly. So that's the sweet spot for health and exercise. And that's like five, six hours a week, maybe three, depending on the intensity, something like that? Yeah, we discussed the exercise medicine. There's actually the ACSM, American College of Sports Medicine. They have this exercise medicine campaign where they have... Really big studies, longitudinal studies, following people for years, doing exercise and diet, how they could control. Because the recommendation is at least 150 minutes per week of moderate activity, but you see more benefits if you do that for endurance training. 300 minutes, which is about an hour, five times. Per Week. Okay, so like, so yeah, so you do see a benefit going from two and a half to doubling that to like five hours, right? Yeah, the science showed that very clearly. They still are going to the, even better to the bottom of the chain. And so is, does this even count as like, kind of like moderate walking pace? Like, is that level of aerobic activity? So like, you gotta be, you have the talk test for that, right? If you, the ideal intensity, if you don't want to go a little bit more intense. Because they also have recommendations for higher intensity workouts. If you go at a higher intensity, you can cut the amount by half. So it's either 300 minutes for endurance or moderate. intensity, or 150 for higher intensity. So like tempo threshold, maybe a little... Threshold is usually more than that. You don't need to go above threshold. It's more than enough for health purposes. And if you do a mix of that, and on top of that, at least two sessions of strength training per week, that's the recommendation, general recommendation. But again, of course, each person is different. As you said, well... Ideally, once per year, get a medical clear C, because when you exercise, as we mentioned the allostasis, we are adapting. 99% of the people adapt physiologically, normal adaptations, they get healthier, they go to the bottom of the J-curve, but a small percentage may have an adaptation that's not physiological, it might be pathological, and then you may be a higher risk. when doing exercise. For example, one of my former clients, his father was active and he died while he was pedaling at 59 years old. He was healthy, he was active, but still he got a heart attack at 59 years old. So you don't expect that. That's not the normal for the majority of the population, but it can happen. So can you try to anticipate that? That's when the medical clearance really come in and should help pick up those cases. But again, and that's after the bottom of the curve, going back to your question, if you train more than 300, which is the majority of our clients, it's questionable. Most people, they do find, even if they train more for years, the science itself doesn't have all the answers It's probably for the first time ever in human history that we have people exercising for so many years, for so long, and doing those long endurance rides before it was common for people to die at 40, 50 years old. As medicine progressed, people are living longer, exercising for longer, and what are the risks related to that? I still believe... The risks are really low. I don't see a reason why to limit, even for health purposes, if you like to go longer. But again, do your medical checkups once per year to make sure you are not one of those poor guys that cannot exercise as many hours as you would like to. Yeah, I mean, even somebody who's perfectly healthy and with a calcium score of zero and stuff like that, The risk of heart attack is still non-zero. You can get a blood clot that can cause a heart attack or pulmonary embolism or something like that. The risks are definitely non-zero. One of the figures I've seen from one of those papers that's burned into my mind is the J-curve the error bars are actually somewhat small going on the, you know, zero activity level going down to like that kind of three to six hours a week. And then beyond that, those error bars get pretty wide. Because as you increase the duration intensity, like, you know, the acute risks seem to go up. You know, you're just out in traffic and there's risks associated with that. I wanted to ask... for people who want to maximize health. Because there seems to be this thing where VO2max is important, but it's also not important. And so how much for just pure health and decreasing of morbidities, where's the line between I need to be at my genetic maximum versus this is enough? you know so it's like if I'm if my VO2max right now is like let's say like 35 or 40 um and it could be 60 but if by if by exercising I increase it to 45 should I get to 60 is that better health outcomes it's it seems like the the answer is it's very much it depends on your your inherent risks factors uh so I don't know what do you think there's I I know that's not really a question but Yeah, yeah. Well, actually, I applied that to myself. My family history is not one of the best for cardiovascular and diabetes risk factors. But so I think a view to at least 40 is ideal. Yeah, 40. And I would, if you can get to 50, I would say for health purposes, that would be a really good number for in comparison to the... the average or the distribution of the population. And just looking at the central aspect of the adaptations, and people often tend, and I think that's, again, what we showed well with the cardiac rehab paper, they had the central adaptations hindered because of the heart problems they had. So when you look at where they adapted, It's probably under muscle fibers. So they increased their ability to exercise. And maybe, of course, VO2 increased a little bit. But simultaneously, they also improved their muscle fibers levels or their ability to contract and to do exercise, to move around. And that's also important, not just for your capacity to use. oxygen, but also to metabolize any other things like glucose and prevent diabetes that's related to exercise in this case and your health, of course, which are the top two preventable diseases, cardiovascular and metabolic, if you will. Yeah, and it also seems to me, again, as a health literature total dilettante, that one of the easy ways to actually improve your VO2 max is to lose fat mass. Because I think that, oh boy, I'm really going to get in trouble with this one. So again, very much correct me if I'm wrong. The healthy range of fat mass is actually, it's fairly wide for men, if I'm not mistaken. It's something like 10 to 20% roughly, or even higher, 25% maybe. But if you're looking to just improve your VO2 max to think about that aspect of health. If you're 25% body fat, getting down to like 15% is going to drastically improve your VO2 max, right? And so also like what are the health implications of just being leaner in general versus all the other potential health outcomes of like you can be healthy at 25%? Well, going back to the exercise medicine, you reminded me of... Big study that they did with overweight and obese subjects at the time. And what they showed is because we've got to make a distinction. When you think about VO2 max or VO2 peak, as some people prefer, you have the absolute, which is you don't divide that by your weight. And then let's say it's four. So just liters per minute. Yeah, liters per minute. Or you can be relative as that's when the body. Fat Mass can make an impact when you divide by the body mass, which takes into account the fat tissue. But what they found out is even if you, let's say you are overweight and you are sedentary and start to exercise, if you start to exercise, you are going to improve both VO2 max absolute and relative, but probably more important here is that you are improving the absolute VO2 max. And then, You are improving your health status, your chances decreasing the risk factor, but you are still maybe overweight, obese, because it's not easy to drop weight fast and probably not recommended. Yes, definitely not recommended. But over time, you might be able, if you continue, if you stay consistent, kept it fun, you might drop the weight and have... more if you add, especially if you add strength training and have proper diet, then you increase the fat-free mass and decrease the fat mass. So at the end, you are working both ways. You are improving your ability, the health of your heart and your lungs by exercising, and metabolically, you are decreasing the burden of carrying all that extra. Fat Mass, which is, you know, a well-known risk factor for cardiovascular diseases, inflammatory diseases, and metabolic diseases. Yeah. You want to give us a couple of listener questions? Yeah, why not? All right. So, again, go follow me at Empirical Cycling for any of these. So, what is your most interesting learning? over your years of coaching. Most interesting. So I guess personally to you, what's the thing where you've been most fascinated? The response to exercise, individual variability. I am still fascinated. I don't know if you ever looked at those studies, but we know from I think the 60s papers from twins, with twins, that about 50% of the variability in exercise performance comes from genetics, the other 50 from the environment, your training, whatever. And up to this day, we can only, and that's the reason why I did my PhD, to try to improve my tools with genomics, we can only explain 2% of that variability. So it's still like a huge black box on the genetic, the epigenetics, and the proteomics sides of things. When you exercise, how you adapt. I think there's a paper, it was done in Australia, where they showed that when you exercise, there are more than 400 markers that get released into the blood and could go around your body and maybe get, it's like kind of maybe some sort of communication between the system and the organs. So we have no idea how these things are talking to each other, the brain with the kidneys, the gut. the muscle fibers. But there is the answer to why someone that's like four watts per kilogram cannot get to five, six watts per kilogram. Why his muscle fibers don't adapt as someone doing a very similar training regimen and don't get there. And I think that's fascinating, so much variability between riders. very consistent training, doing their best to be fast and quick or faster, but we don't get the same answers, the same adaptations. Why is that? That still fascinates me that we can't answer that. I've seen a couple of papers to that effect where they're also looking at familial components. So like how heritable is your training response to exercise? And I think it was something like, oh God. It's way more than zero, but it's not 100%. I'd say like probably R-squared is like I think 50%. It might be as low as 40. It might be as high as 70 in my memory. Boy, this is going to be a really rough one. I do want to do a podcast on that one day because I think actually some of those studies are some of the few that have really looked at the individual variability of a training response. But yeah, I agree. That's actually a very fascinating one. Okay, other question. How much does position impact muscular development? So like road bike versus mountain bike versus TT? Because I think this is actually a very fascinating topic because as a former bike fitter, you are probably aware of even the individual variability of people to fold themselves into really weird positions on the bike. And some people can pedal fine. And for some people, like if you lower their saddle two millimeters, suddenly their quads are going to explode after like a week of training. Yeah, that's a really good question. And yeah, you're right. It was amazing when I was doing bike fits. I mean, the high-performance cyclists, when they jump on the bike, it seems like you're looking at, I mean, most of them, but it seems like you are looking at a machine. The balance between the muscle chains are very... They don't waste energy. And answering the question is what I believe and what I think is you are going to develop the muscles that you are using because that's the principle of specificity. So how can you change that? As you said, well, if you change your position on the bike depending on the bike fit and also the modality of cycling that you are doing, you're going to be changing a little bit. the activation of the muscles. So I think the big question is, what's your target event? What are you targeting that you want to be faster? If it's general cycling, just be a general faster cyclist, then we maybe have a broader, more general answer, just optimize for comfort, economy, and then you go. But if you are going to be a time trialist, then it's a different approach. You see on Tour de France how much they invest. to be so specific for that race, that time trial on that day, even that way different helmets to not say other things, and that we find, well, that's odd, but, you know, they want to win the race. The sandpaper on the saddle. Yes. A perennial classic, so to speak. But that also goes to the muscles. If you want to be a faster time trialist and you are not training. the position and the activation. I remember nearby when I was doing a bike fit, there was a lake, it's an 18 kilometer loop, and one of my clients came for a bike fit, and his handlebar was too far and too low, and just by making it more comfortable and more economical, he... stopped wasting a lot of energy that he was using to support his torso, and that energy or that blood was diverted to the legs, and without doing anything else, he was able to drop four minutes on the loop, just because the position was more economical and more comfortable. So I think that the overarching take-home here is that is that you're probably not going to gain anything by changing your modality. It's not like mountain bike position is best for VO2s and TT position is best for threshold work or anything like that. I absolutely think that you're correct about the principle of specificity here with the muscle recruitment. But I think there's also a point where the bike position can get bad. Yes. and somebody's particular biomechanics are not optimized for a position. And so like this has certainly happened with a bunch of my clients where their saddle will like slide down, not two millimeters, but we're talking like five to 10 millimeters. And after a couple of weeks, they're like, man, I feel like I'm overtraining. And I'm like, this is exactly the same thing we did last year. Like, why is it different this year? Like then we go over the nutrition, the sleep and everything. And then it's like, can you go check your saddle height? for me. Just humor me. It's like, oh yeah, I'm down like two centimeters. It's like, okay, well, that explains everything. And we're going to give you a little bit of rest, let your muscles recover. Because I think that a good position is fine, but I think a bad position on the bike is sort of like having bad nutrition. Like you can have... Nutrition is permissive for recovery, but having a good position on the bike is permissive for actually getting a good stimulus. That's not ridiculous. And that's when you go to the basics. The first one is anatomy, as you said. Depending on the proportions between your torso and the legs, you may be fine to fit stock options for bikes. But like my case, I have short torso to my legs. It's always very hard for me. Ideally, I should have a custom bike, but I cannot afford one at the moment. But ideally, I should have one with a top tube that's shorter than stock bikes for my recommended size for my leg length. And so that's one point you did it. I think it's very valid. I actually see your bike behind you. You've got a giant stack of spacers under your stem, yeah. But that's too long for me. Actually, that's the indoors is not too bad. The other one is worse. I mean, to make it right. It's impossible to get the right fit with a regular stock bike for me, usually. And the other thing is muscle physiology. When you look at the force, length and force charge for... Muscle Contraction. There is an ideal length of the muscle that when you start contracting, if you think about pedaling the bike, that if you are on a bike fit, let's say even too low or too high of the saddle, you are not on the ideal lengthening of the muscle fibers. And then you lose your ability to generate the force ideally as you should. And that's where... I mean, that's, yeah, that's, I was kind of hinting at that with my bad bike fit kind of thing, because I actually was thinking that maybe we shouldn't get too deep into that one, but like, no, it's okay, because what you're talking about basically is like cross-bridging. And so when, it's sort of like if you've got, like, I'm doing hand gestures on a freaking podcast. So like, let's say you lace your fingers together. and the tips of your fingers are in the webs of the fingers of your other hand, right? And so you've got full bridging between everything. And this is sort of like if you're doing like a bicep curl, like if your elbow is at like a 90-degree angle. So you've got a ton of cross-bridging. You can generate tons of force. And as you extend your elbow, you lengthen these muscles. And like now only your fingertips are on top of your other fingertips of your other hand. and so like now you've got 20% cross-bridging and so in order to create the same amount of force that you need suddenly you've got to dig into really really big motor units and they're not that well trained most of the time and this is not a hack to train them either this is actually very bad so yeah so personal biomechanics are a big factor and some people are great at this some people are not so much and I've certainly coached people both ways and you know this is also another really good thing about having an experienced coach is like we can kind of spot what is probably like a bike fit issue versus what's a nutrition or a sleep issue versus like what's a are you maybe getting sick kind of issue like you know these are kind of things that you know I think we're actually probably pretty decent at spotting a kind of ahead of time okay next question is when is it not a good idea to use RPE I actually really like this question yes it's a good question All right, I'll start. Yeah, yeah. I think RPE is, I think when, kind of like we said earlier, when the very Type A people or, you know, people just want to ride harder, you can rickroll yourself into thinking that riding hard is actually riding easy. and part of it's because if that's all you do and that's the easiest you ride, that's your baseline expectation and any less than that is like, well, this must be too easy or it just could also be a thing where like somebody's bored. I totally get that. Some of my favorite rides I've ever done have been on my cross bike on a mountain bike loop, just smashing as hard as I can and because there's, it's never not stimulating. You know what I mean? And so I think when you are trying to not trust your RPE, it's like if you've got, there's a bad metaphor for it, but if you've got eyes bigger than your stomach, that's when to not trust your RPE. Or if you know, we don't have a ton of people who do this, we have a couple where you know what your coach is going to give you if you say this was really fucking hard. and you don't want to rest. You're going to be like, ah, easy peasy. Ain't nothing but a peanut. Like that kind of stuff is going to get you more hard work. And then when you fail those workouts, you're like, ah, yeah, I, you know what I mean? Well, yeah. So that's a good example. When you, I, I putting it in different words is when you don't know how to use the scale, don't use it. Or if you, if it was not cross-checked against other. Variables, like maybe the power thresholds or power rate thresholds. Talk test. Yeah, talk test. So that's when I think it's usually if you are, you said, well, if you're trying to cheat, say that was easy, it was not. Game the system. Yeah, game the system. Don't use it. It's going to be, not going to be helpful for you. Yeah. And I think also, Some people think they shouldn't trust it when they should. Because thinking about the concept of the master gland, if it's really humid all of a sudden, that's going to affect your RPE. Environmental conditions have a huge effect on this. And pretty much everything you listen to in the article has a huge effect. Off-bike stress has a huge effect. It's not like you get on the bike and suddenly that's all gone. Like your body does not just reset because you've now swung a leg over the saddle. Like it's, if it feels harder, it does not get you more adaptation, first of all, but it's telling you something. And that's something where I think, you know, it's like if you're trying to do a threshold workout and suddenly today it feels like, like way, way, way harder than usual. You feel like you've got to dig super, super deep to get. get the watts done. That's a sign that it's not like you shouldn't trust your RPE. It's like, at this point, you should note that your RPE is very different from usual. And, you know, it's, that's one of those situations where it's, even if it's not your usual, it's like, oh, I shouldn't trust my RPE. I just, I skipped lunch and I had no sleep last night. I should ignore my RPE. That's not the right way to do it. Yeah, when changing environments, as you said, well, it's really good that maybe in the first few days, wait for the system to reset, and then you may have a valid RPE again, altitude, hot and humid, things like that, indoors. Yeah. Oh, here's a good question. Asking for my dad, heart rate and watts are lower when he rides his e-bike, but the RPE is higher. Why? That's a funny one. And I have an e-bike because my girlfriend's a lot faster than me. And if I want to ride with her at all, I usually have to get on that one. And I got to be honest, I kind of hate my e-bike in some ways. And part of it's because the Q factor is so wide. And so I think that bike fit plus... depending on the way that it delivers power. If it's one of those e-bikes that will push harder with you as you push harder, that can maybe be part of it. But also, if it's just going to give you 80 watts or 160 watts or whatever as you go through the modes, that's a little different. But I think that part of it's probably bike fit, but also part of it's probably maybe there's something about the... Speed that you're going in relation to the output, that's unusual, and that kind of disorientation can affect your RPE, and I've actually worked with quite a few people who, when they get off-road on their mountain bike or cross bike or whatever, where suddenly they just, they literally can no longer push hard, and it's, a lot of the time comes down to the fact that they don't trust their grip, and so they're Their brain is like pulling timing, as it were. And so I think that might be part of it, but there's a lot here potentially that I think we just don't know. So I don't know. What do you think? Yeah, you said you made a good point about the biomechanic difference, but I was also thinking about his perception of speed at the different power level. More pacing training that some people are really scared of. So that might be because of the higher speed, although power is the same. And of course, it's more dangerous. So that might, I would say, it may explain why he's perceiving the effort differently. That's a great thought. Actually, yeah, I almost forgot about that, the inertia. Yes. So some people like myself, like Coach Megan, we are great. The more speed, we get, the more comfortable we are. And the lower speed we get, the less comfortable we are. And it requires some practice to get us being able to climb well. And we talked about this in the last Coach Roundtable podcast. And so that may be a big factor too, where your father is just not comfortable pushing at higher speeds. And this is something that I actually had in my notes to talk with Jim about, and we didn't really get there. because obviously Gemini could talk forever about anything like us here. We're about to be another two-hour podcast. But there's a lot that goes into cadence and how the brain is or isn't comfortable with certain situations about motor unit recruitment and rate of force development, things like that, and self-selected cadence. I mean, we barely understand that, I think. 10% of what goes into all these factors. Yeah, it might be an extreme example, but just like driving a car. When you are driving, you can go really fast, but if you are on the passenger seat and the person is driving really fast, stress goes high because something is different. I know in this case it's a different situation, but I was thinking even like roller coasters. when some people have fun, so others almost die, like myself, because of the accelerations and the unpredictable things that may happen. So that might be, again, I think might be related to his motion perception, that might be. But that's one idea on the hypothesis. Yeah, very interesting. Yeah, so it's fortunate that we don't have a real answer for this, but I hope you enjoyed us speculating wildly. Here's one I get very commonly actually, especially when I start working with a client who's never really used RPE before. When thinking about RPE, is it about the session as a whole or do you think about your peak RPE? So like if you've got intervals, let's say you've got four by five minute VO2s on a four hour ride. Do you think about your RPE for the VO2s or do you think about it for the other three hours where you're just kind of noodling? Yeah, when you have intervals, During a session, if you want to be really comprehensive, I would have like one RPE for the general session, the overall feeling, and I would add in the comments or as a workout feedback, I would say the RPE for the first and the last interval if you want to be economical on the text or the RPE for each interval because it will be helpful to understand. the effect of fatigue over time, how that changed your perception of the effort, although power, let's say, is the same for the workout. And then if it's, let's say, endurance or a tempo ride, it might make sense to use. I prefer to see just the average for the session. You can go deeper in the comments again, but because depending on the terrain or the course, you may... Like a long hill, it's going to be harder, although the average was three, but the hill was five. So you can add that, but that will be similar to intervals. Yeah, I usually also tell my clients to whatever they decide they're going to use, be consistent. Yes. And I'll meet them where they are with this. And so like, if you do, and my kind of general way to sum up the whole thing is like, When you get home, look back on your ride and be like, how hard was that? Like right as you hit the door, look back and what RPE was that? So four hours with VO2s plus like three hours of endurance, that might be like a six or a seven, right? Or if, you know, if they were like sub max VO2s, you might put like a four or five, not sub max VO2. That's ironic. Yeah, that's an oxymoron. You know what I mean? Like sub-max, like hard efforts. So I think that that's also where like fueling and hydration, like as your article notes, would be very important because like if your hydration has sucked for the last couple hours, like it's one of my very strong contentions that the entire world is dehydrated at all times. And so drinking a little more doesn't hurt. Yeah, that kind of stuff always has an influence on your RPE. And so this is why, you know, the kind of the comments utilizing those really well is great for us as coaches because we understand the context a lot better. And especially when somebody proffers something like, oh, this felt harder than usual, but I also dropped half my food out of my pocket and I couldn't go back and get it. Maybe that's why this was harder. Probably. For sure. Let's fix that next time. Let's zip your pocket up a little better. And next time, hopefully, that's not going to be an issue. Yeah. Yeah, I agree. And people, I don't know if you ever discussed this in the podcast, but as you dehydrate, the viscosity or the thickness of the blood increases. makes it harder. I mean, that's one perspective. Makes it harder to pump that blood that's thicker now. So, because one thing that we- You can see this when you get your blood drawn. Yes. I've been very dehydrated getting my blood drawn versus like being you hydrated and well slept and like, for one, your blood comes out like syrup and the other, it looks like you're just filling a water bottle. And there is a point that we didn't discuss that it was also related to the original work is some Scientists and even subjects, they can rate the RPE or the CR10 for the legs and the overall feeling, which sometimes it's different. Most of the time they go together, but there might be days when you feel like, oh, it was easy on the legs, but it was hard on the cardiovascular system. So in theory, you could use RPE for separate in this case to make it even more clear what was the problem that day. Yeah, well, TrainingPeaks only has one RPE input box. So yeah, that's again where the comments come in and are extremely helpful. So before we really wrap this up, any other thoughts that you had on the way that we didn't quite get to dig into that you wanted to share? Well, I think we covered a lot. It was a nice discussion on how training should be distributed or periodized, follow a periodization. How hard it is to tackle everything and how, but I think the most important aspect is the role of the client or the athlete. Many times I think they, and it goes back to the matter of education that us as coaches should always be helping them or you is to, you gotta be part of the process. The more you become part of the process. the more effective our work will be because then we can relate more and more our experience to what you are going through and improve the prescription so we get to the point where the training is really effective it's done at the right intensity and the adaptations happen as we expect and even with all of that it's still a lot of art really hard to predict how things will adapt, how you will respond to each difference in training, like how to do training, heat training, but that's the fun part of it, the process, and we need you to be part of the process to make all of that science that we discussed really helpful. Yeah, and I also know a couple people who I think can get caught up in their heads a lot of the time with thinking about like, Oh God, was this a five or a six? It doesn't matter. Just put down a number and yeah, it's really don't overthink it. And it's like, you know, this is also what your coach is here to help you do. Or if you're self-coaching, I mean, this is another reason. We did a podcast forever ago on like why you should leave feedback for yourself, even if you are self-coached. We went into a lot of that. And so I think, yeah, even though like Having a coach takes a lot of the burden off of what should happen when, and like, you know, we've dug through all the literature so you don't have to. It's not like, you know, it's not like your burden has gone from 100% of planning your own training and like doing the whole feedback loop and everything. It doesn't go down to zero when you hire a coach. It goes down to like 10 to 20%. You know, it's like, and, you know, it... We don't require novels in our training piece comments, but we like to know the context and it's so, so incredibly helpful. And we have a lot of really excellent clients who give us great feedback. And if you want to be one of those clients, yeah, that was a good transition, right? 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