INSCYD and the Power of Testing Analysis, with Sebastian Weber

We compare and contrast various test methods based on three key aspects: 1) the protocol, 2) the data the test provides, and 3) the analysis you can perform with that data.

INSCYD testing Trevor Connor and Chris Case

If you’ve been an endurance athlete for any length of time, you’ve undoubtedly performed some type of test to gauge your form, be it a 20-minute on-the-road test or a VO2max test in a physiology lab.

There are many forms of testing, and each has its advantages and disadvantages. Today’s episode is all about comparing and contrasting the different test methods based on the three key aspects of any test:

  1. the protocol
  2. the data the test provides, and
  3. most importantly, the analysis you can perform with that data.

It turns out there are vast differences between the various methods, and before you choose the one you want to perform, it helps to know how much time and energy you need to invest to get the data you’re looking for, and then how to use that to inform your training and racing.

We’ll analyze each protocol based on its simplicity, the challenge of the workout, and its effectiveness. Then we’ll discuss each method’s outcome, the value of the metric, and its accuracy.

Finally, we’ll focus on the analysis of each test, why it is the most important thing to consider, and how you can use the data you generate from any given test.

Our guest today is Sebastian Weber, lead physiologist for INSCYD. You’ve heard him on Fast Talk several times before, and we’re happy to have him back this time as we forge our partnership with INSCYD.

It’s test time.

Let’s make you fast!

Episode Transcript

Chris Case  00:12

Everyone, welcome to Fast Talk your source for the science of endurance performance. I’m your host, Chris case.


Chris Case  00:20

If you’ve been an endurance athlete for any length of time, you’ve undoubtedly performed some type of test to gauge your form, be that a 20-minute on the road test, or VO2max tests in a physiology lab. There are many forms of testing, and each has its advantages and disadvantages. Today’s episode is all about comparing and contrasting the different test methods based on three key aspects, the protocol itself, the data the test provides, and most importantly, the analysis you can do with that data. It turns out there are vast differences between the various testing methods, before you choose the one you want to perform, it helps to know how much time and energy you need to invest to get the data you’re looking for, and then how to use that data to inform your training and racing. We’ll analyze each protocol based on its simplicity, how challenging it is to complete, and its effectiveness. Then we’ll discuss each methods outcome, the value of the metrics, and its accuracy. Finally, we’ll focus on the analysis of each test, what is the most important thing to consider, and how you use the data you’ll be able to generate from any given test. Our guest today is Sebastian Weber, lead physiologist for INSCYD, you’ve heard him on Fast Talk several times before, we’re happy to have him back. This time, as we forge our partnership with INSCYD. It’s test time, let’s make you fast.


Trevor Connor  01:58

Fast Talk listeners, we’re really excited to be building this partnership between INSCYD and Fast Talk Laboratories. We’ve already had a few members sign up, and take the INSCYD test, and this is what they had to say about it.


Fast Talk Member 1  02:09

I dig this. I enjoy the challenge of self-coaching, but what I’ve been looking for is someone to bounce ideas off and help me interpret my progress.


Fast Talk Member 2  02:20

I went through the analysis of my INSCYD test results with Coach Ryan, and I have to say that it’s totally worth it. I’m definitely planning a check-in mid-season.


Trevor Connor  02:29

Join these members, and learn how to fine tune your training to your body, your race, and your goals. Sign up today at


Chris Case  02:43

Welcome back to Fast Talk Sebastian Webber, it’s been a long time since we’ve had you on the program. It’s a pleasure to have you back.


Sebastian Weber  02:50

Yeah, thanks for having me once again.


Chris Case  02:52

And I must mention the fact that you are the lead scientist at INSCYD, and Fast Talk Labs and INSCYD now have a partnership. So, we’re really excited about that, we’re really excited to be working with you more closely.


Sebastian Weber  03:05

Yeah, we are also very, very much looking forward to that the whole team really is very excited, and we’re cheering about when they have heard about this new partnership with you guys.


Trevor Connor  03:15

That’s great to hear, and we feel the same. Our head coach Ryan Kohler, he actually comes from CU Sports, which was a top performance center here in Boulder, but the issue with a center like that it’s location based, we could really only serve as people here in Boulder. So we want to do something like that of that caliber, but make it available to everybody make it available to all our listeners, all our members and partnering with you at INSCYD really gives us that, because this is basically lab caliber testing, but it’s something you can do at home, it’s something you can do on Zwift, you don’t have to be here to do it. If any of you are interested, we’ve created a few videos about how to do INSCYD testing, what it’s like, what to expect from the experience, including Chris and I on Zwift, ripping each other apart on an INSCYD test. If you want to check those out, go to our website at


Chris Case  04:16

Great. Yeah, the previous episodes where we’ve spoken with you, Sebastian, we have touched upon the the power of physiological analysis, we really want to get into that today. Compare and contrast a lot of different methods when it comes to quote unquote, testing. What are those different methods? What are the protocols? What does each measure? And what do you get from it in terms of analysis? There’s a lot out there, and we want to walk you through step by step and compare and contrast these different methods. So that’s the emphasis of this show today.


Sebastian Weber  04:54

Perfect. Let’s do that.


Three Considerations When You’re Figuring Out How Do You Want To Test

Trevor Connor  04:56

Yeah, well, let’s so when I was doing my research for this, I was actually kinda surprised at all the different ways now that you can get a data and do testing. Certainly, when I started out my cycling career there were basically people thought there were there were two ways, one is do that 20-minute test, the other one is find a lab and get an metabolic cart. So, I kind of grouped it all. So, one category is just what we’d call threshold test, really, they’re just trying to get at what’s your threshold power, FTP, and that’s your 20-minute test, your 60-minute test, there’s your Maximal Lactate Steady State Test, MLSS, Critical Power Test. Another category of tests that you’ve seen more and more of is this power profiling, where you’re trying to get at different numbers, not just what’s your threshold power, but what’s your sprint power? What’s your one-minute power? Maybe what’s your five-minute power? And different tests will have different protocols, then there’s a whole new way of looking at it that’s becoming increasingly popular, which is through the software, using something like your power duration curve, which just accumulates all your data, over a given period of time creates this profile of you based on your peak numbers that you’ve put out, well, while riding and racing, and says here’s a profile of you, so you never actually have to do a test. And then finally, there’s what I would call your physiological test, which is getting a little more under the hood, and that’s your metabolic cart, and and what we’re going to talk to Sebastian about with INSCYD. Sebastian, you brought this up, and I thought this is a great way of looking at it, and this is how we’re going to talk about the rest of the show is there’s three considerations when you’re figuring out how do you want to test. One is, what’s the protocol? Second one is what is it measure? And the third and really most important is what analysis can you do?


Sebastian Weber  06:54

The analysis is the one that is most important, that’s really why you should do any kind of testing, to work with the data that you get out of it. In terms of efficiency, or usefulness, or value, you want to compare basically, how difficult is the protocol? What effort needs to go in there? What can I do with the analysis?  How can I leverage the data? And if you have more embedded data, you maybe accept a little bit more comprehensive protocol, or a little bit more logistics around it, and if you have not so much data, lots of good data then maybe it’s okay, if the protocol, not taking up too much time, right?


Trevor Connor  07:35

Yeah, I think that’s a really important point. Because I will frequently have athletes come to me and say, “Well, I did this test, no told me about this complicated protocol, and then they’ll give me numbers.” And they think this is about getting numbers, but the important question that I often throw back at them, “what does that number mean?” And sometimes I can answer those, “Great. You got some numbers,” you know, you can put out a really big hour for X number of minutes, but what does that tell you? How do you use that for your training? What does it tell you about where you’re at, about your physiology? And they can’t give you an answer.


Different Protocols of Testing

Chris Case  08:08

Yeah, if you’re going to spend the time, energy, and investment in doing something what we’re hoping I think in part, to clarify today is there are some that give you a lot, and there are some that don’t give you as much. So where should you invest? All right, well, why don’t we talk about the different protocols for these tests, and we can start with that threshold test group.


Threshold Test Group

Trevor Connor  08:35

Yeah, we’re gonna pound through this really quickly, because we’ve talked about almost every single one of these protocols in past episodes. If you really want to dive into the 60-minute test, or an MLSS, test, look for those episodes, and we covered it pretty thoroughly. So, this is a fast, let’s get through this. And first of all, it’s really important to remember when you’re talking about test protocols, there’s a couple factors to look at. One is simplicity, how complicated or easy is it? How repeatable is it? If it is an absolutely killer test that you were able to get through once but generally don’t get through, that’s probably not a great test. And then later on, we’ll get into the effectiveness of those. So as Chris mentioned, there’s a bunch of threshold tests that really all they’re trying to do is get you one number, what is your FTP or threshold power? You have a 20-minute test, which is 20-minute time trial, and generally you multiply that by 95%. That’s the protocol created by Dr. Coggan and Hunter Allen. True FTP test is a 60-minute test, but that gets into the difficulty, 60-minutes is really hard, but it’s going to be more accurate, if you can do that. A couple others just give you that threshold number, your MLSS test. I’m just going to say that’s really difficult, that’s where you have to do multiple 30-minute time trials taking lactates, to figure out exactly what power you lactate levels level out at. So, it’s a fairly accurate test, it’s really good for lab testing. If this is something that you’re just using to figure out your own training zones or where you’re at, it’s not the sort of test you want to do. Critical power test, there’s different protocols for it, it requires shorter efforts, often a three-minute effort is used. Again, we covered that in depth, it gives you a threshold number, it also gives you what’s called your watt prime or your anaerobic capacity. So, check out we did a whole episode on MLSS and critical power, check out those if you really want to dive into those.


Multiple Metric Tests

Trevor Connor  10:43

The next type of test is these multiple metric tests. So, the classic example here, or one I really like is Neal Henderson’s 4DP test. So, this is like the 20-minute test, except you do more than just the 20-minute test, the 4DP, for example is a couple five-seconds sprint’s, a five-minute all-out effort, then you take a break, then you do a 20-minute all-out effort, then you take a break, and you do a one-minute effort. Chris has given me this strange look that basically says he thinks I like it because it really hurts, which it does. What it’s trying to get at is given you more than just that threshold number, it’s trying to get at your different energy systems, and give you a sense of their relative strengths. So, there are some benefits to do in a harder test like this.


Power Duration Curve

Trevor Connor  11:34

But moving down the list, there’s tests that really aren’t a test, probably the most common one is looking at your power duration curve. This is really hard to explain, so do a search for this, we’ve talked about this in previous episodes. But it’s basically a graph that shows all of your peak wattages, from one second all the way out to the longest ride you’ve done. So, it just takes all of your training data, all of your race data, and says here’s the best five-minute effort you’ve done, here’s the best ten-minute effort you done, it literally takes every single second, you know, and says, here’s the best wattage that we’ve seen, turns that into a graph and then normalizes it, so kind of rounds it out into a nice-looking graph. Benefit of that graph is technically you don’t need to do any testing, and that comes with a big Asterix, but it also shows you a profile as an athlete and the shape of that graph will really tell you a little bit about what you’re like. I give an Asterix to the testing, because it takes all your training data, but the thing is, if you’re not massaging that graph, you can get something weird. So, for example, I don’t do any sprinting in the winter, that affects the shape of the whole graph. So as a result, the longer duration parts of the graph where you get into that FTP power tends to be a little higher, because I’m not doing sprints. If I then do a sprint in the spring, I’ve seen this a few times, I do a single five second sprint, and the next thing you know my threshold power has dropped 20 watts, because it’s the first time it’s seen as sprint, that’s sprint has completely changed the shape of my graph. So, while power duration curve technically doesn’t need testing, to actually be able to use it, to make it beneficial, you need to massage that graph, you need to go out on fairly regular basis and do efforts of different lengths to make sure that that graph is accurate.


Lab Testing Type Tests

Trevor Connor  13:43

Another thing that we have covered very thoroughly in past episodes is your lab testing type test. So, this is we get you on a trainer in a lab, and there’s a whole bunch of different ways we can test you I’m just gonna break into two categories. One is we hook you up to what’s called a metabolic cart and do a VO2max test. So that’s we’re fairly rapidly raising your power and measuring your oxygen consumption, tell you what your VO2max is, and can also give you a lot of other information about your physiology. A different type of test is a lactate test, where you can use the full metabolic carts to measure that oxygen consumption, but you don’t have to. The key thing is you’re taking blood lactate at regular intervals. This sort of test you have stages, they can be anywhere from about three minutes, up to the typically three to five minutes I’ve seen them up to 10-minutes. So, every say five minutes, we’re increasing your wattage a certain amount, measuring your lactates, and then create a lactic curve and that will show you where your threshold is at, along with a whole lot of other information about your physiology. The key thing about these lab tests is they’re getting inside looking at your feet physiology as a rider.



Trevor Connor  15:02

And finally, that brings us to the INSCYD test, which actually, the focus here isn’t the protocol, the focus here is on the analysis. INSCYD is somewhat agnostic, so we could actually, if you did a lab test, a VO2max lab test, or a lactate test, that data can be used in the INSCYD platform. If you just have a bike and a power meter, then there’s protocols that you can do, and they again, can be somewhat agnostic. It’s similar to 4DP, where you need a sprint, you need efforts of varying length. So, the one that Chris and I did were a three-minute test, a six-minute test, and a 10-minute test. But you can do a variety here. So, Sebastian, do you want to talk more about that?


Sebastian Weber  15:50

Yeah, so sprint test is meant to it’s meant to measure your glycolytic power, your VO2max. So, how much energy over time, how much power you can produce in your anaerobic lactic systems, so called glycolysis. And then the three-minute power is used to you know, to get the value of your VO2max, which is actually using an already is a sprint, so it is a combination of both to get your VO2max. And then the six minute and to 12 minutes, combined with three minutes, pretty normal power duration relationship to get a good proxy of your threshold value. And then what is different in there, compared to just the normal power duration curve, we are looking at physiological numbers, you need to put in your gender, you need to put in your body weight, you need to have an approximate at least of your body fat, so that so that we can that we can get a rough idea of your body composition. This is all important because this is makes up those numbers especially when you talk about things like VO2max, and fat and carb combustion and so on. So, what it then does then, it cross validates the data against each other. So it’s, you know, it’s impossible that you have, for example, an extreme outlier in the spread, which does not fit to the other data, the software would flex it, right? So, there’s kind of a quality control built in there.


Trevor Connor  17:18

So, Sebastian, yeah, I think you brought up a really important point which you were just talking about the protocol in terms of what it measures, and that is the really the next really important consideration with all these protocols. What does it measure? And just as importantly, how accurately does it measure these things? So, when you’re looking at these protocols, you have to consider, what is it tell me? How well does it tell me that? And also, as we were talking about with the protocols, how easy or how difficult is it to get there? Doing 20-minute tests, and just multiplying by 95%? That’s pretty easy to do. But you look at the research, not overly accurate. MLSS really accurate, gives you one number, really hard to do.


Chris Case  18:04



Trevor Connor  18:04

Not a lot of fun. So that’s something you might just use it in a lab. When we look at all these tests that we were just talking about, Sebastian, you had mentioned this to us off mic before and I really liked this analogy of how much does it let you peek under the hood, in terms of what it’s measuring. So, we talked about all these different tests for threshold power, they are just giving you one number, what’s your threshold power? So, think of this, it’s just telling you how fast you go, that’s it, it’s not telling you anything about your physiology. When you get to some of the little more sophisticated like these 4DP, that power duration curve tell you a rider type. So, you look at my power duration curve, I’m in pure time trialist, it’s practically flat, if you look at a sprinter, their power duration curve, or if they did the 4DP test, or their sprint power is gonna be really high, but as you get to that 20-minute power, it’s gonna be really low. So, it gives you a little more information, but I would say it’s just letting a peek under the hood. The difference with these more physiologically based tests, so that’s your lab test, or the INSCYD test is this is letting you look at the engine. So, it’s telling you, it’ll tell you what your threshold power is give you a little more about your profile as a rider, that all these other tests give, but on top of that, it’s going to look at what’s your fuel usage? Are you relying more on carbohydrate? Are you relying more on fat? Ut’s going to tell you a little more about your oxygen consumption, about what’s going on with your lactates. So, it’s going to give you a lot more information that tells you not just how fast you can you go, what’s your particular number, but how is the engine generating that. So, it’s letting you look at the engine which I think is really important, and I loved your description of your protocol there, because your protocol does have some precision to it, so that you can get at these aspects of the engine.


Chris Case  20:02

Inexperienced hands, all of those numbers also don’t mean a whole lot, but if you have them and you put them in experienced hands, you can do a lot more with them, you can manipulate training more, you can be a little bit more sophisticated with training, a little more targeted with training, if you are able to look at the engine in this analogy, look under the hood, figure out how the rider is producing the numbers and then use that to inform training and sometimes racing. Whereas with the others, it’s a number, but you’re kind of using it in a blind way, if that makes sense? Well, let’s turn our attention to that most important part, the analysis. What does each of these and that analyze? Trevor?


What Do These Tests Analyze?

Trevor Connor  20:51

We said this at the beginning, I think this is the really important point to make. You can do these tests, and you can get these numbers, but what can you do with those numbers? So, this is where you get the value in the test, and as I said, I have frequently had athletes come to me and go, “I did this test and it really hurt, and here’s a number.” So, there’s just nothing after that so.


Threshold Test Group

Chris Case  21:15

Yeah, yeah.


Trevor Connor  21:15

It’s unfortunately, sometimes I have to tell him that go, “well, great, you have a number. But we really can’t do much with this.” So, it’s what you can do with that number, and that’s the analysis, and that’s really the most important part of the test. And this is one of my issues with these threshold tests is you do get that number, so people go well look at my FTP is this and you go, okay.


Chris Case  21:41

It’s one dimensional.


Trevor Connor  21:42

Right. So, if you’re doing a 20-minute time trial, tells me a lot.


Chris Case  21:46



Trevor Connor  21:47

And I can really help you there. If you’re doing a three-hour road race, with a sprint at the end, doesn’t really tell me how you’re going to do and that road race at all.


Sebastian Weber  21:57

Like for the 20-minutes time trial, it helps you to understand what would be approximately the power output.


Chris Case  22:04

Right, right.


Sebastian Weber  22:05

Because you have this 20-minute, and then what do you do is that, I mean, do you sit down and take the CDA and kind of project what you know what the time would be? I mean, don’t get me wrong, sorry, I’m a little bit provocative here. But for the 20-minute power itself, that’s, it is a benchmark, and don’t get me wrong, it is a great benchmark, it is maybe as good as a 10-minute benchmark or a 5-minute benchmark, as you said, depending on your race, right? If it’s a three-hour race as a sprint, then it’s maybe not so relevant for you, if it’s a 20-minute time trial, it’s maybe more relevant, because you could monitor if you do this test again, and again, you can monitor your progress for this 20-minute, right? And what this reminds me to a little bit is back in my school days, we will do Cooper tests, you know, Kenneth Cooper, from U.S. Air Force, 20-minutes running, and looking how far you get. That’s basically your 20-minutes test. It was meant to check, you know, what’s your performance? But it was not meant okay, then you can maybe there’s some, as you said, some limited accuracy, extrapolate to what your threshold is. But how much does it tell you about how you should train? So, it tells you your power, but it doesn’t necessarily tell you what you need to change in training, right? And that’s kind of the limitation. So, it’s easy to do, it’s fast, It’s doable, you can do it yourself in training, you don’t need many tools, software, hardware whatsoever, just look at the average power. But because it’s so easy, maybe it’s also has its limitations, right?


Multiple Metric Tests

Trevor Connor  23:44

So I’ll tell you that actually the most useful thing I find when somebody sends me a file and says, “here’s my 20-minute test,” is I need heart rate. And I like to look at their heart rate response to it. So, to give you an example, as I said, I’m a pure aerobic animal, I’m not sure there’s a fast switch muscle fiber anywhere in my body, so when I do a 20-minute test, you see my heart rate shoot up, and then it’s relatively flat across the test, and then it comes right down. So, I see that profound go kid, there’s an aerobic animal. Now, I have had athletes that put out the very similar power to me, for example, but you look at their heart rate, and it starts low, and you just see this very rapid rise over the whole 20-minute test. And that tells me this is an athlete that doesn’t have quite as well developed an aerobic system, and they’re actually relying a lot more on anaerobic power. So, it’s an indirect way to get out some information about the athlete, it’s not as good as some of these other tests, but if I do see that and see that very sharp heart rate, I go, “you’re actually riding above what your aerobic system can do.”


Trevor Connor  24:50

When we get into those more multi metrics, like the 4DP, or let’s even talk about the power duration curve where you’re seeing a little more of a profile to athletes. I think there’s some more analysis you can do there. So, for example, again, I’m a time trialer, you look at my power duration curve, or if I do the 4DP test, my short duration powers are really bad. But as you get longer duration, 20-minutes out to an hour or even longer, my power stays pretty consistent. So, you see that profile of a time trialer, versus, for example, Chris is a climber, so you see a pretty good five second power, really good power, and that kind of one-to-five minute range, and then decent power in that kind of 20-minute to an hour range. So having that sort of information, I think tells you a little more about what type of rider you are. But Sebastian, what are your thoughts on this?


Power Duration Curve

Sebastian Weber  25:47

You get, let’s say, not a quantitative but a qualitative analysis, or I can say what kind of rider you are, you obviously get a better understanding, so to speak, if you have data, you can compare yourself, right? If you say, my 20 seconds power, my 30 seconds power, is compared to my peers relatively low or high. It allows you to compare yourself better. I think, in terms of training zones, which is what obviously, most people use a simple FTP, 30-minutes, 60-minutes, whatever test for, it is, is not doing a much better job, and it doesn’t have to, I mean, it’s not really making a big difference in improving your performance if you’re training zoners to 2% higher or lower. But yeah, it does give you, you know, a good understanding on what kind of rider you are in a qualitative way, if that makes sense.


Trevor Connor  26:45

So, one of the advantages of something like the 4DP, or the power duration curve, as it allows a lot more individualize zones, the issue with zone, and this is how it used to be done, zones were all based on percentages of FTP. So, everybody’s, so if you look at the classic Coggan zones, everybody’s what was called the VO2max zone, I think that was zone five, was up to 120% of FTP power. That might be really good for one rider, might be completely offer another rider. So, the nice thing, when you look at his power duration curve is you can individualize it much more based on your profile.


Chris Case  27:25

what about are we moving to the physiological tests now and the analysis you can get from them?


Physiological Tests

Trevor Connor  27:32

Yeah, and this is where it gets fun, because again, this is where you get to look at the engine. So, you get those numbers, you’re going to get an estimate of your threshold power, you’re gonna get a lot of those numbers you get in the other tests, but this is where you really get to start peering inside, look at what’s going on. So, it’s not just what is your threshold power? But how are you generating that power?


Chris Case  27:55

And for those who haven’t picked up on it, yet, that’s probably why they named the company NSCYD, because you’re peering inside with a little with a little science twist.


Sebastian Weber  28:05

Part of it. Yes, that’s true.


Trevor Connor  28:08

When you’re trying to look inside, when you’re trying to peer into the engine, what are the things that you’re trying to look at? What are the things that are really important to see?


Sebastian Weber  28:19

The general concept has nothing to do with, you know, with NSCYD the software. The general concept is, and that is, you know, very familiar for everybody from other fields, from other expertise, is that when you try to optimize something, when you try to optimize a process, when you try to optimize a product, when you try to optimize or fix something, so to speak, because that’s definitely, you know, at the end what you’re trying to do with your training, right? You’re trying to fix your performance, you’re trying to optimize your power output, for a, b, c, different specific events. Then what you would do, and what you would expect an expert to do, like an expert like in this case, let’s say your coach to do is to sort of sit down for a moment, and analyze, you know, analyze the effort, understanding is the effort, and then go in and understand what are the limiting factors? What is limiting this athlete from you know, reaching a higher performance? Higher power output? Higher speed? Faster time, in a specific event? Find out about those, and then you are able to tweak those, and this is again, this is the whole concept like they always say when you when you bring your car to garage because it’s making a funny noise or something is broken, you expect the guys to investigate and research, what is you know, what is broken? And the same goes when you see a doctor or you know, any kind of consultancy, you would expect to first looking under the hood, looking at the engine, and understand okay, what can we do to improve? Do we need to make the chassis lighter? Do we need to change the gearing box? Do we need to, you know, have, you know, more reps or whatever? And that is, at the end, honestly, it’s independent of INSCYD, right? You could also go in a lab for one or two days to get the same amount of data, right? You could do a Wingate test or some kind of shorter sprint test to get to get a grip on your glycolytic anaerobic capacity, you could do ramp tests additionally, for your VO2max, an MLSS test for your threshold. And so, as a main benefit for you as an athlete is now what INSCYD is doing the typical, you know, scenario or typical case of digitalization, the very place the good portion of, of manual testing and labor by algorithms. So, you get this whole profile, you can look under the hood, you can look at the engine, and understand much, much better, what is limiting my performance? And which lever, so to speak, I have to I have to push, which knob to have to turn in terms of how do I have to design my training, in order to improve my performance further?


Importance of Looking at the Engine, Not Just the Numbers

Trevor Connor  31:18

So, I will actually want to give an example here of the importance of this analysis and getting into the sticking with this metaphor, taking a look at the engine versus just getting these numbers. So, I had an athlete that I’ve been working with for a few years, he lived in Washington, D.C., and there was actually nowhere that we could get him in to be tested. We were having this really strange issue, where about an hour and a half into races, he was getting popped. And so I had done the 4DP test with him, I knew his numbers, you know, what was his five minute power? What was his 20-minute power? His sprint power, his one-minute power? And he was getting popped at wattages, is that he does look at and go based on the testing, you should have no problems doing this wattage, so what’s going on here? And tried different types of intervals, nothing seemed to be working, finally got him to come out to Boulder, and we did the full battery of testing on him. So, we got him into the lab to take a look at him and discover two things. One is he had had a crash, right before I started working with him, he had a bad crash where he completely snapped his femur and did some muscle damage. So, we discovered that he wasn’t on his right leg. He was never fully restocking his glycogen. And then from the test, we discovered that he was a glycogen consuming animal, at very low levels he was starting to really rely on glycogen, and not really use fat for fuel. So, what we’re discovering is, you know, again, just looking at power numbers wasn’t telling us this. What was happening was in that race, even when it wasn’t going that hard, he was blowing through his glycogen. By the time the race got hard, about an hour and a half in, he didn’t really have in his one leg, he didn’t really have any glycogen left to rely on, and just couldn’t go hard and couldn’t put out the sort of what it is he could put out fresh. That was something that you could only figure out by doing this sort of testing, where you can actually look at what’s going on with this athlete.


Chris Case  33:30

Speaks to the point about using the right diagnostic tool for the issue. You were operating blind, you had four numbers that you were quite certain of, but they told you nothing about the problem.


Trevor Connor  33:44

Right. Well, if you just looked at his 20-minute FTP test, it was almost comical, he would do a 20-minute test, and he would average 350 watts. And then he would get popped in a race and it goes, so in the race, there’s a point I was going really hard, and that’s where I got popped, I just couldn’t hang on. You go you’ll see it in the data, and I’d have to contact and go, “I don’t see it in the data.” And he’d have to tell me where it is, and I look at and go, “you did four minutes at 300 watts and got popped.”


Chris Case  34:10

Right? Does not make sense.


Trevor Connor  34:13

Like you can do 50 watts higher than that for 20 minutes, and we could do all the FTP tests in the world. It was never going to tell us what was going on with him.


Chris Case  34:22

Yeah, because that four minutes happened to be an hour into the race,


Trevor Connor  34:26

hour, hour and a half.


Chris Case  34:27

Depleted the thing he needed to produce that energy at that point in the race.


Sebastian Weber  34:33

Yeah, it reminds me to a story I had about two years ago, I was coaching a guy, professional guy, he was riding in our top ten in World Time Trial Championships. And I’ve been coaching him for a long time, and we had a similar problem. We couldn’t get into the lab, or we didn’t have any any testing real testing opportunity, right? But of course, I have all the power data, I have all his power data, from racing, from training, like, you know, without any blind spots there. And we kind of stagnated in his training process like he was, he was okay, but he was not at his level, right? He couldn’t be in the final on the road race, he wouldn’t be in the final and, you know, the classics and struggle to do his job for the team and different things. And, and, you know, what I was, I looked at the power and analyzed it was, you know, like power duration curves and the efforts and so on, and I was absolutely sure what was going on. I was reassured I really honestly, I was sort of telling myself, you know, what, I’ve been doing this, this physiologic testing for 20 years at that time, approximately, and looking at power data, and you know, seeing it all so to speak, and I’m pretty sure what’s going on, I’m pretty sure his VLA Max is X, and the VO2max is Y, and this is this is the issue, and this is what we needed to work on. And he was, he was in a training camp with his national federation, and there was a physiologist, and they had the opportunity. At this time, we didn’t have this PPD technology, so inside testing would rely on lactate measurement, at least. And so, he was in a training camp, we had a physiologist with him from the from the former national federation, they were able to do a lactate test and tested him. And turns out that what I was reading from his training and race data was more or less the opposite of what was going on for real.


Trevor Connor  36:38



Sebastian Weber  36:39

Really. So, it was all it was all the sorry, experience and looking at the data and so on and so forth. I was just, you know, totally on the wrong track. And it shouldn’t be so surprising, because look, if you know if could be simple to just to just do this look at power data and figure it all out, then there would be no need to go into a lab, right? Then you wouldn’t have to take your athletes into a lab, and then they would not need any human performance labs beside for whatever scientific research. And then and then we are inside we would not need, I don’t know how many 1000 lines of code, and I don’t know what big kind of servers to crunch the numbers, right? Then if we could all as humans just figured out in our heads, adding up some numbers. If it would be that simple, then then people would not have to do it this effort. So, looking at from this perspective, it should not be so surprising that it can happen that we look at data, look at the raw data and think, “oh, yeah, I know what’s going on.” But yeah, you double check, and maybe a nine out of ten cases you were right, but the issue is that one guy is a 10th guy where you are wrong, he is very unhappy if he trains to the wrong direction. And turns out, this guy by the way turns out that we changed his training, and six weeks later, he was again where he has been before. So, we’re just some minor tweaks, and here you go again.


Trevor Connor  38:15

No, I completely get that. That’s the exact same example with my athlete, and I felt like a horrible coach because we were trying everything, and it just wasn’t working. We needed to look at that engine, we needed to see what was going on.


Sebastian Weber  38:29

Yeah, and it’s really bad for this one athlete, right? It’s really bad for this one amateur or recreational athlete who’s investing a lot of time and trying to, you know, squeeze out some extra training time. And it’s also bad for a professional who’s trying to make a living out of it, and you know, it’s fighting for his next contract. So, nobody wants to waste this time with the wrong training.


Ryan Kohler  38:54

Hey, fellow coaches, we’re starting our new coaching community here at Fast Talk Labs. Join us at any level by April 30 for access to our new workshop on how our coaches are using INSCYD. Then, apply for access to our coaches only forum, where you can ask questions and get answers from other colleagues on a variety of topics, including INSCYD, athlete management, testing, new research, workout ideas, and the business side of coaching. Learn more at


INSCYD Allows People To Have a Lab Anywhere

Chris Case  39:25

So one thing I want to be sure we clarify is the power of the INSCYD PPD protocol, this power performance decoder protocol, which allows people to sort of have a lab anywhere. And in your the case of your athlete, Trevor, you were able to get them to come to Boulder, get them into a lab, but that’s you know, that’s kind of expensive. If you had been able to get him to do the INSCYD test protocol, and analyze the data with that software, you would have been able to sort of diagnose this problem much sooner and much more cheaply.


Trevor Connor  40:06

Well, I don’t think I’m gonna say anything to you you’re gonna disagree with here, Sebastian, metabolic carts are great, you get really good data off of them. As a matter of fact, your analysis software, if you have that metabolic data from a cart, you can bring it in to yourself or to be part of the the analysis. The issue always with a metabolic cart is access, and that was the issue my athlete had, I was telling him a year and a half before he finally came out to Boulder, we need to test you. But that’s a big expense he had to fly somewhere, he had to pay for the testing, and he wasn’t fully convinced, well, obviously afterwards, he was very convinced about the validate.


Chris Case  40:49



Trevor Connor  40:50

So this is a way of getting at the same data, but it’s a protocol you can do on your trainer, or it’s a protocol, you can go out in the road and do this and then send the data. That allows you to do this sort of analysis without having to travel to where you can find a metabolic cart. If we had INSCYD, we might have solved this a year and a half earlier with my athletes.


Sebastian Weber  41:14

Yeah, no, I mean, it’s perfectly right. And this is not only a problem in cycling, I mean, you know, I have been working for decades, in professional cycling teams, and I came from a lab background. So for me, it was, it was always a kind of a pain, it was always, you know, unsatisfying to have lab testing, you know, like once a year in the winter time, so to speak. The the benefits of value from having physiological data is really amplified if you if you have the data continuously, right? If you can retest, like you say, when you have a specific issue, or you or a suspicion that you know, something is going on, something has changed, and, and you as a coach, or that you think, well, it would be great to have that data. And yeah, that was really part of the main motivation, you know, creating INSCYD.


Trevor Connor  42:02

This was always a bit of a pet peeve of mine, is some labs you go into and they want to put you on this top of the line, really expensive Velotron bike or an SRM bike, and go, “well, we’re giving you the most accurate power numbers.” And whenever my athletes go and get that test, and they go, “Oh, that got great numbers, because it’s on an SRM bike.” I just go, “what if your power meters 20 watts off of that bike?”


Sebastian Weber  42:27

Yep. Yep.


Trevor Connor  42:28

So I actually I’m very big on test you on your bike, because that’s what you’re going to be training on. So the closer you can get it to reality, the better.


Artificial Lab Testing Scenarios

Sebastian Weber  42:39

And we have, we have professional cycling coaches now actually, spreading the day out the testing out over three, sometimes even four days, the effort. And the feedback is, yeah, you maybe have a little bit more noise in the data, right? But coaches feel that they have more applicable data, because you kind of get the average over a whole week, whole training week. And what often happens, especially when people try to prepare, especially for testing in the lab is that you have kind of this artificial scenario, right? Where you maybe have a week of unloading, and two days rest, and then a specific nutrition or something. And then you have to ask yourself, okay, how good do those numbers really reflect what’s going on and training? Right? When you want to use the data primarily to make an informed decision about your training? So yeah, what we have seen is that coaches really appreciate to, to not try to create this artificial lab testing scenario, but test as close to real life conditions as possible. Power Meter being one part of that.


Trevor Connor: INSCYD Data Analysis

Trevor Connor  43:53

So I think this really goes back to the importance of the analysis. And so, what we thought we would do today, that would be kind of fun, and thank you, Sebastian, for being willing to do this. Chris and I both did the test, so we want to give a few examples of the analysis. Sebastian hasn’t seen our data, so we’re going to just give him our data today and see what he comes up with. So, Sebastian, if you’re your game for this, why don’t we start with my data? So, my target event this year is a four-day stage race. So, I’ll be doing the hopefully the pro one field, possibly the one two field, so it’ll be kind of domestic, U.S., kind of Cat1.


Sebastian Weber  44:40

Right. Okay. So, you know, similar to what I tried to explain before, what you want to start with here is understanding the efforts that decides the race, right? I mean, in most cases, there are certain decisive moments, could be an attack, could be a sprint at the end, obviously, depending on the tactics, depending on the race, depending on whoever’s there. So, to understand what you’re aiming for in training, we want to understand what are the race demands here. I give you an example. Next weekend, I go to a ski race, cross country skiing, the race is approximately two hours, a little bit more than two hours, but the race the size of moment happens on a climb, just before the finish, which will take approximately four minutes, right? And so, the competitors in the last year have always been close together, before the on the climb, and then on that decline kind of separates and, and, and the entire race is decided. So, the first step here would be to understand which moments would decide the race? Or which moments did you have in the past, lose the race, right? Where did you get dropped? To understand which domain more like of two minute, or five minute, or whatever it is, which domain of power output you’re trying to improve, and hopefully, you know, we can construct a number here, on what would be the power output that would allow you to whatever is the is the demand, stay with the pack or actually win the race?


Desired Outcomes

Trevor Connor  46:24

With this particular race, I would say first day is a 10-minute hill climb time trial, I would like to not embarrass myself there. Ten years ago, I did well there but don’t think I’ll do that again. But would like to not embarrass myself, then it’s two road stages, I’m not going to be a guy for the GC, I’m not gonna be on the podium, I’m looking more at in one of those two road races, which are rolling, they have some hills in them, to hopefully get into a breakaway, that would be to me a huge success for the race.


Sebastian Weber  46:58

whatever do you need to go into the breakaway, to drive the breakaway?


Trevor Connor  47:02

Probably two minutes all out to get a separation, and then another five to 10 minutes of well above threshold to solidify it, and then after that, it’s probably going to be a long period at or close to threshold. So actually, 2011 I was in the all day breakaway and I was the virtual leader on the road for the whole day, or most of the days, so.


Sebastian Weber  47:23

Okay, so the numbers I do have here in race conditions is 71 kilograms, and for three minutes, an average power of 447. So, let’s approximately 450, right? The other effort I have is 10 minutes for 26. Okay, and if you just keep your performance of your last test was 62 VO2max, but you just drop the body weight, because of the drop in body weight your VO2max will go up to a notch below 66. If your VLA Max is approximately .25, which again equals to a little bit below 600 watts for 15 seconds here in your case. You could not do those efforts most likely to be honest, because basically the amount of glycolytic energy you would need to produce not really be able this this was that low VLA max. So, what you need to think about is when you when you race hard, you fatigue, and you accumulate a lot of lactate, and your creatine phosphate levels drop, and your pH level drops, the drop in pH level inhibits your glycolytic energy production. And for the stream effort was 0.25, you’re basically too far off, you know, your maximum glycolytic power is not is not high enough, then in a case when it would not be integrated, so like a clean sprint, right? From standing start from rest, there will be no problem to produce the amount of power you would need in this case. But for 43 minutes, we again all these, you know, fatigue metrics so to speak kicks in so a drop in the creatine phosphate, drop and pH levels, and basically what I’m saying is you’re inhibiting an already VLA Max, glycolytic energy release will not be enough to cover to cover what you need, because your VO2max was 66, you know, it’s approximately only 380 watts. So, you’re asking your glycolysis to produce another 75 watts, approximately, and that would not be possible. So, you would need you would need a VLA Max, I can tell you more in the range of .45 in order to do that, okay, for the three-minute effort. And for the 10-minute effort, because it’s longer and it’s you know, it’s obviously lower power, it’s not that far away from your VO2max, right? For that you could still have a VLA max with a little bit below 0.4, and still be able to do it.


Trevor Connor  50:25

So, my issue is going to be the jumper in the field.


Sebastian Weber  50:28

Right. So, it’s a jump away, to jump away and to stay away, that’s the tough part, because your VO2max is only approximately 280 watts. This is what you can produce aerobically, and in two minutes or two, two and a half minutes effort, you will burn quickly through the you know, through decreasing your creatine phosphate stores and just what happens when you hit VO2max. And then the additional energy needed is not you know, you cannot cover that under these conditions with visitors at low VLA max. So, 0.4-0.45 is what you would need to see, or obviously, you could just increase your VO2max, right? So that’s, that’s the other part of the game. If you are saying you’re not able to increase your VLA max, you could, you could go with a VO2max in the ballpark of a little bit above 70, and then be able to do it.


Chris Case  51:31

Or you stick a frame pump in the spokes of the person sitting on the front of the field, cause a massive pile up right behind you as you go, Trevor, that’s the only way you’re gonna be able to pull this off.


Trevor Connor  51:45

I think might have done that at some point.


Chris Case  51:48

Were you in a movie once?


Trevor Connor  51:49

Quite possibly. Yeah, I mean, obviously you’re getting my February numbers, and I wasn’t in great shape. So my hope is that I’ll ride, but definitely that comically low VLA max is an issue. So, what would you be telling an athlete like me to do to get that to where it needs to be?


How To Get the VLA Max Where It Needs To Be

Sebastian Weber  52:09

Right, you know, difficult or the complex part of your training program is going to be to increase your VLA max a little bit by still maintaining or increasing your VO2max, right? This two-minute effort, it’s highly efficient because yeah, in two minutes you will max out your aerobic system. So more than 80% obviously energy and indeterminate effort is coming from aerobic system. So, you know, focusing on making sure that you don’t lose VO2max in training is of absolute highest priority, right? For the VLA max, in your case, because you are naturally low, right? It’s not like you are kind of average VLA Max, but because of the training and nutrition you have done, your now lower, that’s not the case, obviously, right? So, in your case, I would really focus on short sprint efforts, and I would definitely put you in the gym and really focus on, in the gym for example, focus on weight and the load that enables you to do approximately 15 repetitions in about 20 seconds. So, you would need to do it fast, and you are not allowed to rest in between, right? To really also say in the gym, have a high-power output, on an isolated form like an elect press or something. That’s one thing I would do, and I would try to keep it timewise away from your endurance training. So separated it, space it out as good as possible, instead of going to the gym and direct you do a three-hour ride or vice versa, right? That will be the most important pieces. And if you have seen a higher VO2max, and here we go back to why it is important, why it’s helpful to test regularly? If you see a higher VO2max, whatever last year, two years ago, then I would definitely look at the training you’ve done before to get kind of an idea. Maybe tweak it a little bit obviously and use this as a starting point to get your VO2max up a little bit. A low VLA max of .25, I would be very careful in your case, can be totally different than somebody who has a different VLA max, but would be very careful with to high intensity in terms of interval training, or if so, not long ones. So I would like for the high intense stuff, I would be very careful to apply anything in your case longer than 40 seconds, because the reliance on the glycolytic system will be very high and again, it’s not it’s not super strongly developed and it’s not going to be great fun for you, and I would totally avoid something like two minute all outs or three minute all out, I would either go like 30, like very high end but really short, or something up to a maximum of threshold, but everything in between so to speak, I would avoid in your case. And then definitely, of course, look at the total training hours to make sure that you get in enough hours to keep your VO2max high, because what is often overlooked is that a good high and especially stable VO2max comes from a good high stable training volume.


Trevor Connor  55:39

That’s really interesting, because when I look back on my best years, I’ve done this analysis to figure out what’s the work that really benefits me. One is I need to be in the weight room almost all year round and is exactly the sort of weight training that you’re describing. And that’s been an issue for me this year with COVID, because the weight rooms are all closed, so I haven’t been in the weight room. Number two, I used the to do the two minutes on, two minutes off intervals, and switch to more of a Tabata styles. I was doing 2010s, 1515s, 3030s, and was much more successful with those as my high intensity work, which is exactly what you’re describing. And then yeah, I always need to do big volume in order to be able to compete. So, you got me spot on, that’s pretty fascinating.


Sebastian Weber  56:28

Thank you.


Trevor Connor  56:30

Chris, are you ready to give Sebastian your data and let’s see what we discover.


Chris Case: INSCYD Data Analysis

Sebastian Weber  56:35

Give me your numbers.


Chris Case  56:36

Okay, what do you need here?


Sebastian Weber  56:38

Give me your body weight, body composition, approximately body fat.


Chris Case  56:44



Sebastian Weber  56:44

And VLA Max and VO2max off your INSCYD testing.


Chris Case  56:48

Okay, so body mass 62.7 kilos, body mass index 20.5.


Sebastian Weber  56:57

No, give me body fat.


Chris Case  56:59

Body fat of 6%.


Sebastian Weber  57:02

Really? Okay.


Chris Case  57:04

You said VO2max?


Sebastian Weber  57:06



Chris Case  57:07

65.1, or did you want the total?


Sebastian Weber  57:11

Doesn’t matter. I can.


Chris Case  57:12

Okay. And then VLA max .52.


Sebastian Weber  57:16

Okay. And you said 62 kilograms?


Chris Case  57:22

62.7, yeah.


Sebastian Weber  57:24

Okay. Okay, good.


Sebastian Weber  57:25

Okay, cool. And what do you aim for? Like, what is your goal?


Desired Outcomes

Chris Case  57:31

So the event that I’m doing this year, is a bike packing race across Ireland. It’s 2500 kilometers long.


Sebastian Weber  57:41



Chris Case  57:41



Trevor Connor  57:42

Yeah, that’s what we said.


Sebastian Weber  57:45

Is Ireland’s that big?


Chris Case  57:47

Well, if you ride on every road that touches the Atlantic coast, then yes, it’s kind of like riding through the holes of the brain, you know?


Sebastian Weber  57:57



Trevor Connor  57:58

It’s not a straight line from one part of Ireland to the other at all.


Sebastian Weber  58:02

This is where the 6% body fat came from?


Chris Case  58:04

I’m hoping to actually add weight by drinking Guinness and eating scones the whole time, but we’ll see. I’m probably gonna burn some calories too.


Sebastian Weber  58:14

Right. Yeah, how many hours do you train per week? Like 12 approximately? Or what is your approximately?


Chris Case  58:21

Yeah, you know, I would say probably 12-14, on average, a big week for me would probably be 20-24.


Sebastian Weber  58:35

Ouch. Okay.


Sebastian Weber  58:36

And how often do you do that?


Chris Case  58:38

Oh, once every three months.


Sebastian Weber  58:40

It is not straight in terms of there’s a lot of altitude, there’s a lot of vertical measures, you have to cover right?


Chris Case  58:47

They are not long sustained climbs there, but there are some punchy steep stuff.


Sebastian Weber  58:52



Chris Case  58:53

And it’ll add up over the days.


How To Attain Desired Outcome

Chris Case  58:54

Sort of your data, and what you’re aiming for is, from a physiological perspective, it’s relatively straightforward, right? Because it’s not a bike race, where you need to combine endurance with this sprinting effort at the end, or being able to jump into a group if you know what I mean, right? It’s not about repeated high intensity effort. So, so the event, your goal, which, you know, is much more straightforward, right? Now, your physiology therefore is also a bit more straightforward, because checking boxes here, okay, yeah, sure, you know, that checked. For the for the amount of training that you’re doing, like already discovered, the VO2max of 65 is very good, right? It is, it is a very good VO2max, per se. And what we see here is, you know, different from Trevor, is actually that, for what you’re trying to do your VLA max is relatively speaking high, or let’s put it this way offering the biggest room for improvement. This is not because point five something is per se, a super high VLA max, this is because the influence of severe, your substrate utilization, so on how much fat and carbohydrates you’re using, or the distribution of this, the influence of severe MX increases this of your VO2max. So, if your VO2max would be 40, then we would not have to, you know, to bother about the you know your VLA Max. But because your VO2max is 65, and most likely, we will not get it to 80 for your event. VLA Max is the, you know, is so to speak the biggest lever, or the biggest knob you have here, as you know, it offers the biggest room for improvement, especially, you know, with your, with your VO2max, and you can see it in the data I’m just looking at, for example, if you’re fat compassion curve, which is, you know, it’s it has says, you know, like, you know, this, this curve has an apex, right? It’s like a bell curve, and it is pretty symmetric, which means the bell is, yeah, more or less in the middle of the curve, and if you have your VLA max would be lower, it would be more asymmetric. So, you know, the apex is the highest, the fat max would be shifted closer to your, to your, to your threshold power. And that is especially because, yeah, you have to carry some weight with you, not your own weight, but from your bike and equipment, everything you’re taking with you, you know, increasing the combust rate to higher power, and, and having a fat max at higher power output, and sparing carbohydrates in this race, you know, 2500 kilometers that is the main goal. So, first conclusion here basically, is you need to get, you need to get your VLA max down. And this race couple of months out, the good news is that, you know, there is also there’s also enough time to do that, right?


Chris Case  1:02:36

So, interesting, because most of the time, people think, “oh, I want all my numbers to be higher,” you know, in a very simplistic way, people are just striving for more, whereas you’re saying the VLA max needs to come down or should come down, that’ll improve other things that will help me through a race like this. So the question becomes how does one reduce or lower their VLA max number?


Sebastian Weber  1:03:03

Yeah, which is actually has become a very, very popular question. Because people don’t understand that this brings up your FTP, and because everybody’s so focused on FTP. This is a very popular question. However, you just learned in Trevor’s example that it’s not all about FTP. So, there are many, many cases where you should bring VLA max up. But anyway, so.


Trevor Connor  1:03:27

I was going to say with me, everybody’s asking you how do you bring your VLA max down? My question is can I bring my VLA Max down?


Chris Case  1:03:34

No. You set the standard for low, and everybody’s relative to you.


Sebastian Weber  1:03:43

Yeah, yeah. So bringing it down, can be tricky. I would even say it can be sometimes be more tricky than actually bringing it up. Because look, there’s a little bit of an issue here is that, your VLA max comes a lot from the more fast twitch or obviously the more glycolytic fibers, because this is what VLA Max is, right? Glycolytic power. So, what you want, you want those fibers to adapt those muscle fibers, but those fibers you will only recruit either when you start with fibers that are already fatigued really a lot, or when you increase intensity, you start to recruit more of those fibers. The issue is when you increase intensity, you have more anaerobic, you know, energy release and therefore you are in the dangerous so to speak to to to apply a training stimulus which is actually has a positive influence in terms of increasing your glycolytic power performance. It is a little bit of a fine line here. The most classic approach and a little bit of a trick is to say, okay, we go to an intensity at approximately threshold. So for you somewhere in the ballpark of 260 watts, we go to approximately threshold. And then, which is where you really start to, you know, recruit a lot of those more fast twitch fibers, and then increasing the top by reducing the cadence, because, you know, increasing the torque, you know, potentially also recruits more source FT fibers. So, in your case, you would sit more at a threshold zone slightly below threshold, maybe even this would be one thing, you can ensure do regular on a regular basis. On top of that, I would, I would recommend to go too low to use intervals, which are approximately 20% above threshold, so in the ballpark of 300-310 watts for you. Because looking at your data, your utilization of your VLA max at this intensity is below 10%. So, it’s still relatively low, so the stimulus on your glycolytic system, you know, is not huge, you are only accumulating 1.11 millimolar of lactate, 1.2 millimolar of lactate at that intensity. So, you can, you can sustain it for several minutes, and I would actually combine that using this as kind of primary efforts. So, I would use those kind of intervals, for maybe like four to six minutes at 300 to 310 watts, I would use those as a primer to slightly decrease, slightly decrease your glycogen, and then either in the next session, or on the same day, use these more, you know, torque related effort to your recruit your FT fibers as well, but not producing that amount, that high amount of lactate. And then the certain really important piece of training for me here would be to make sure that you have a great consistency, you have a great consistency, you would repeat even a small dose of this kind of training. So, you don’t have to do this for two hours of one and a half hour or something per day, but have this kind of training included, more or less in a daily regime. And make sure that your training is not it’s not really so much of a weekend warrior style, that you really try to distribute training, training hours, relatively equal throughout the week, so that you, you know, more or less speaking, go and ride your bike every day and include some of these training methods more or less, not precisely every day, but on a on a very regular basis. So, it makes sense.


Trevor Connor  1:08:08

So interestingly, a few years ago, Chris and I worked together he was doing this race, DK.


Chris Case  1:08:15



Trevor Connor  1:08:16

Unbound now, that was a long gravel race, you’re talking 12-14 hours, depending on how quick you are.


Chris Case  1:08:23

200 miles. Yep.


Trevor Connor  1:08:24

We had similar very similar discussions about Chris, because we knew he was explosive, we knew in a 2-to-3-hour race, he had that, that big power to drop people to be the first at the top of the climb. But we also knew when he and I went out for a six-hour ride, by the end of that six-hour ride, I was able to hurt him, because that stamina was really my strength. So, when we are mapping it out, we are less concerned about the particulars of a lot of the interval work. One of the things we really focus on exactly what you’re talking about is mapping out the weeks and making sure that he was doing consistent bigger volume to fatigue him a bit and keep him pushing through that. We were having him do some big long rides on the weekends, because he couldn’t do them during the week, and often having him doing some efforts towards the end of those rides. And as I remember, the one interval workout that I gave him was hill repeats. Very similar what you’re describing, so they were a little over threshold, but the requirement was they need to be consistent. So, he would do four or five repeats, but you couldn’t be explosive. You couldn’t attack on them. And I wanted that fifth one to be just as fast as that first one, so the one thing that I didn’t think about it makes a lot of sense that you just brought up is getting some big torque work in there as well.


Sebastian Weber  1:09:49

Yeah, and by the way, that said you mentioned that what would need to happen here in your case, Chris, is that because we haven’t talked about how you get your VO2max value of 65.


Chris Case  1:10:04



Sebastian Weber  1:10:04

This whole, you know, this, this whole training like all other training where you try to work on your weakness, you have to make sure that you don’t lose your strength.


Chris Case  1:10:14



Sebastian Weber  1:10:15

Right? So, a VO2max can react in terms of an adaptation upwards and downwards. Within a couple of weeks, you could in a lab test already see a tendency within one to two months, you would have a strong tendency if it’s going in the direction you want or you don’t want. So that is something I would emphasize you’re doing in your case, when you change your training, you know to work on a weakness for example in your case, or work on a potential to say in a positive way, bring down your VLA Max, you want to make sure that, especially if that new training program differs significantly to what you have been doing before, you want to double check and relatively soon to make sure that you’re not hurting one of your strengths. In your case, you VO2max. So, this kind of goes back to the idea, you maybe need to test on a kind of a regular basis, maybe not regular, but you know, in a smart way, so to speak. So it doesn’t have to be static every three or four every three or four months, but in your case, I would suggest a retest, for example, six weeks after you change your training, to understand is that hurting my strength, and not only, you know, working on my weakness.


Chris Case  1:11:39

Sebastian, give us an example, outside of the sport of cycling, we tend to gravitate towards that sport, because we love it and we know it well, but you know, we’re speaking to non-cyclists out there, and I know INSCYD is a tool that’s valuable for other endurance athletes. So, give us an example.


INSCYD Testing Used in Other Endurance Sports

Sebastian Weber  1:11:57

Well, I think one of my most recent examples would be actually from cross country skiing. We have seen athletes trying very hard, you know, to increase endurance performance, so to speak, also in cross country skiing, right? Increasing their lactate profile curve in terms of right shift, which is similar to trying to increase your FTP, this is not a cycling specific thing. This is something in all different kinds of sports, we have efforts in swimming, we have efforts in speed skating, in canoeing, you know, almost everywhere. What we’ve seen, and what I’ve lately seen, again, in in the world of cross-country skiing is that athletes have tried to improve this metric over the years over, you know, several seasons, and have done so successfully. But the race performance didn’t go up. So, the lactate value at a certain speed is lower, or the speed as a certain lactate level is higher. They also do, by the way, sometimes something like 20-minutes test or 10-minutes test, and it’s improved, but the race performance didn’t. Then as I said, I was it his race, and just before that we did some testing on roller skis, where you covered what you use to kind of simulate cross country skiing. And what easily happened, and I had had, you know two guys have that what happened was if you look historically into their data, is that they increased their threshold performance, but by doing that, they actually decreased VLA Max, which could be okay, in some cases, as we have seen, right? But say if also decrease the VO2max. So, if both metrics go down in a certain relationship or certain proportion, then you can still increase your threshold power, right? But when it comes to the race, like in this cross-country race, like it was decided in an attack, I think approximately 15 minutes before the finish, and the attack was approximately three minutes long or two minutes long. So, in these situations, and this is by the way, very similar to canoeing is very similar to speed skating to swimming, right? So, there’s a guy who races maybe only three, four minutes. There’s also some cross-country skiing races, which are approximately that duration. So, the race was won in this attack, approximately, you know, 15 minutes before the finish, in about in a three-minute attack. And yes, the athlete I have in mind here would have been able to stay with the winner of the race after the attack, because the threshold power is high enough, but he didn’t have any chance to respond to that attack. Because in a three-minute effort, as you can imagine, you need a high VO2max, and you need a high VLA max, or a decent VLA Max, right? You have some anaerobic energy contribution as well, the threshold power there, the increasing threshold power didn’t really happen. This was very, you know, on a motivational level, it’s very difficult for an athlete to see, you know, the main number I’m aiming for in training, I’m monitoring is going up my threshold power, but my race performance is not going up. It’s not doing the same thing. So, I was I was lucky to see the race, and see how it happened. And then, you know, it kind of makes sense, okay, the race is two hours long, but it is decided in a three-minute effort. So, your threshold, your substrate utilization, you might think is important, because it’s two hours, but the races decided in a short effort, and just improving your threshold didn’t help in that case, because, unfortunately, the threshold was improved by decreasing both aerobic and glycolytic power simultaneously.


Dangers of Just Focusing on One Number

Trevor Connor  1:15:57

That was really good example of what we’ve been talking about the dangers of just focusing on one number. If this athlete was watching their threshold, they probably went into this race with a lot of confidence going, “well, that number is great,” not realizing that they didn’t have the right assets, the right profile to perform in the event.


Chris Case  1:16:19

Sebastian, you you’ve been with us before, you know how we like to close out every episode, it’s a tough task, but I know you’re up for the challenge. You’ve got one minute to encapsulate everything we’ve talked about here, give us a final message of the most important take home that people should leave us with.


Sebastian Weber Takeaway Message

Sebastian Weber  1:16:36

For me, the most important message of today hopefully was or for me, it should be at least that when you do any kind of testing, no matter what you want to think about how much value it brings for the event or for the goals that you really have. You can look at the example I just made from cross country skiing, you should look at the, you know, how often can you do the testing? How often can you benchmark your performance? How good can you monitor your progress? Because this is where the value comes from, so the testing that you’re doing has to be meaningful for what you’re aiming to do, right? If you know a threshold maybe is not what you need in a race, because you’re aiming for an Iron Man, or the races is decided in a three-minute effort on a sprint, then threshold is not important at all for you. So, think about which metrics are needed for your race? And think about how you can measure test monitor those, and how often you can monitor those so that you can really use it to make an informed decision of your training. This for me should be the takeaway.


Chris Case Takeaway Message

Chris Case  1:17:49

The phrase you get what you pay for is actually not appropriate here, because sometimes you pay a lot, quote unquote, pay a lot by putting in a huge effort in the testing, but you get very little out of it. So, keeping in mind the investment that you’ve put in, whether that’s financial investment in terms of paying for something or paying for a device that you need to do a certain task or, or whatever, or just probably more appropriately the amount of energy in the investment of time into a certain test. You want to make sure that you’re getting well rewarded for all of those efforts. So, keep that in mind when you select the test. And then yeah, the ability to repeat that often to benchmark yourself, to decipher the progress you’re making, things like that, that is also a very important factor in what you choose and how you choose. Trevor, what would you like to close with?


Trevor Connor Takeaway Message

Trevor Connor  1:18:55

I think I’ll close with a theme that we brought up in a few episodes, which is when you are doing testing, this is not racing, a lot of athletes go into testing, thinking this is about performance, and it’s all about getting that one big number and if you can just hit that biggest 20-minute or five minute or whatever, minute power bigger than anything you’ve ever put out, then that’s the purpose of the test and you’ve been successful, and now you’re gonna have a great season. Races are for racing, that’s where you want to perform. Testing is for figuring out you as an athlete, and you want to make sure you’re doing a test that reveals who you are, tells you about your physiology, tells you about your strengths and weaknesses, and allows you to make good decisions, or more importantly your coach to make good decisions about what sort of work you should be doing so that you can perform in the places where it counts.


Chris Case  1:19:52

Thank you as always Sebastian, it’s always a pleasure.


Sebastian Weber  1:19:55

Thanks for having me again.


Trevor Connor  1:19:57

Always enjoy having you, Sebastian.


Sebastian Weber  1:20:01

Do you hear the vacuumizer from next door?


Trevor Connor  1:20:04

No, good.


Chris Case  1:20:05



Sebastian Weber  1:20:06

I need to tell you that it’s crazy, we have neighbors that are vacuumizer their greens, their garden.


Chris Case  1:20:16

What does vacuumizer mean?


Sebastian Weber  1:20:19

A vacuumizer like normally you use to clean your carpet in the house.


Chris Case  1:20:23

Vacuum. yeah, yeah.


Sebastian Weber  1:20:25

Yeah. They are doing this with grass, yeah, we saw that there are no leaves on the grass, twice a day.


Chris Case  1:20:33

Wait a second.


Sebastian Weber  1:20:36

You want a picture?


Chris Case  1:20:37



Trevor Connor  1:20:38

Picking up dirt. They do realize their grass grows in dirt? That you want to leave that dirt there?


Chris Case  1:20:44

Are you in Switzerland or Germany?


Sebastian Weber  1:20:46

Yes, I am in Switzerland. Our neighbors are German.


Chris Case  1:20:49



Sebastian Weber  1:20:50

It’s because of the leaves, Chris. There’s not a leaf allowed or something else on the lawn.


Chris Case  1:20:56

Yeah, there’s probably a 1000 franc fine for having a leaf on your yard.


Trevor Connor  1:21:00

Pretty funny, twice a day.


Chris Case  1:21:02

Wow, that’s amazing.


Sebastian Weber  1:21:03

Sorry to get to detailed. I heard it very loud, I was wondering if you hear it. So.


Chris Case  1:21:13

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