The Powertest

Björn: Hi, this is the Afasteryou Podcast with Sebastian Schlurke and Björn Kafka. Your podcast for aerodynamics and endurance training.

Sebastian: Hello, dear audience. Hello, fellow Afasteryou users and everyone who wants to become one. We have today... We're laughing, and we want everyone, right? Always. Yeah, we have a new podcast for you today. Today we want to focus on the Powertest, reveal some of its secrets, shed some light on the background, say a lot about how to run it, and quite a bit about our analysis and what you can actually do with it. Björn and I thought about how we could set this up nicely for you and developed a little structure and will try to present it reasonably well. But what was actually quite exciting — and we've already talked to Andreas Seewald about this — how he, as one of Björn's athletes who just raced the Cape Epic. I wanted to briefly ask Björn upfront: how was the Cape Epic for you? And maybe you can briefly explain what the Cape Epic even is.

Björn: Yeah, the Cape Epic is an eight-day stage race, a mountain bike stage race through South Africa. It's also commonly called the Tour de France of mountain bikers. It's extreme — a team race. You always ride as a pair, you always have to finish as a pair. And yeah, whoever wins it, especially over the last four or five years — whoever wins it, really has something going on. Nino Schurter has won it multiple times. In recent years Kulhavý — so really, really good guys. The level is just very high. And whoever wins it is really good. And Andi was there with his team partner Matthias Stossek. They were... in second place until the third stage, then even won the third stage and rode out a few seconds more. They were very, very close behind the leaders, but unfortunately didn't quite make it to the finish because Matthias Stossek got a stomach bug and they had to drop out, which is really a shame. On the other hand, the team that finished second was Martin Frey's team with his teammate Simon Stibian from Team Bulls. And they did fantastically well. They won a stage and then secured second place overall behind Saru and Berkins from Team Specialized Songo. And it was simply an incredible performance. Yeah, especially wrapping up a season like that with a stage win and second overall at the Epic is really, really good. And it shows that the work Martin did and also Simon... Simon isn't coached by me, he's coached by Tobias Blum. It all fit right, the parameters were set correctly. That's what's really satisfying when it all comes together — and even when the really big ones with Andreas didn't make it, but then the other team is so successful.

Sebastian: Yeah, what does all this have to do with the Powertest? It's obviously a tool you've been using for a long time for your athletes to do performance diagnostics. And it's another exclamation mark for what you can achieve over a long time when you apply it consistently. And we'll hear more about that now. Nevertheless — Cape Epic, awesome event. Super event. The coverage was a lot of fun. I watched a bit here and there, really cheered for the guys — descents, very technical, great event, fantastic. I was really into it, and when Andi Seewald's stage win came, I thought, wow, the really tough stages are still coming. And Andi had said the day before that he was slowly starting to have fun. I was looking forward to things really getting exciting. And it was exciting anyway, and for you as a coach it was another perspective, and then with the other team you partially support — quite a story. Okay, we owed that to everyone who listened to the podcast with Andi — just a quick update on what was going on. And yeah, as I said, great season, fantastic. And we're glad we could help. And you obviously had a lot more to do with it. But okay, let's get back to our main topic — the Powertest. And a quick question for you, Björn: can you explain the Powertest in one sentence?

Björn: Let me try. So the Powertest is a... fully automated test, a test model that maps metabolic performance — what your metabolism can do — based on power data we can upload, power data in terms of watts. Or also, if we have lab data, VO2max and lactate values — VLamax. That was a long sentence with lots of commas, wasn't it? All good.

Sebastian: I mean, the whole system is more complex in a certain way. Being able to explain it in one sentence is already challenging. You also always assume that a few things are known. What is a metabolic profile? You just used the word. What is metabolism, or what can I imagine metabolism to be as a lay athlete?

Björn: To put it really simply: our metabolism, or the energy we need — let's call it a metabolic profile — is made up of various parameters. Our body is essentially like a hybrid engine. And these individual hybrids, as I'll call them, we can simulate. And then we create a profile. How does your overall performance, your horsepower, come together? From which various modules? And we can calculate that via this simulation. So I know what you can do and how it comes together.

Sebastian: Yeah, that sounds really exciting. And fundamentally — we're all aware of this — we somehow convert energy, we have some kind of performance capability, we somehow produce power. And it's clear that how our own body works can be quite complicated. And that maybe it can't all be explained with just one value is also clear. And the Powertest delivers exactly that now. It definitely takes it one step better than what's been used so far. If you consider FTP, for example — with this simulation of the metabolic profile you can define much more precisely what type you are and how you have to train, if I understand this correctly.

Björn: Exactly, that's how it is. I have FTP, the threshold power, this infamous sustained power — I think there are almost 30 different interpretations or formulations. It's ultimately just a mixture of different systems. Take electric and gasoline, maybe add some nitrous. And that's somehow how this FTP, this threshold power, is composed. And we can differentiate out at least which two parts make up this FTP. Which is of course much nicer, because we can imagine that a threshold power can be composed in very, very different ways. A sprinter can have the same threshold power as a marathon rider. Does that mean they should train the same? Most likely not.

Sebastian: And if I do a Powertest as a layperson — or what does layperson mean? Ultimately, we're addressing a specific clientele who measures their power and has at least some clue, and who also knows they have a certain performance capability. What's my advantage? Or how does it help in my training if I do a Powertest? Or let's say, before we get too specific about what you have to do for it — how much more performance gain can I have over a few years?

Björn: That's always hard to say. Depends, of course. If I'm in pretty unfit shape, then obviously you can get a lot out of that. Performance can sometimes improve by 20, 30 percent in a short time. In elite sport, it's mainly about figuring out how to design your performance capability — let's say — to hit specific requirement profiles with the right mix of hybrid engine and combustion engine. But when I do a Powertest and I don't have super high performance yet, I immediately know with the Powertest which lever to pull. What are these low-hanging fruits I can grab so my performance improves as quickly as possible? And that's the huge advantage. I know exactly which lever I need to pull.

Sebastian: Okay. That's really a big deal and a cool thing. One more quick question about the Powertest. How does it differ from other performance diagnostics? Or what are the big advantages of a Powertest compared to, say, spirometry and a lactate step test?

Björn: So spirometry and lactate step tests always have their place. And they're important. The Powertest is super and brilliant in that I can reproduce it again and again. I ideally always have the same power meter. I maybe always have the same course. I can decide when I do it. If I have a day that's not so good, maybe two days later. Yeah, exactly. So I practically always have my lab with me. That's the huge advantage. Plus this test is automated. That means I upload the data and the program tells me immediately: these are your values. This is your maximum oxygen uptake and this is your VLamax. These are your training zones. We'll get into that in more detail. So I don't need a diagnostician. I save that intermediate step. And the interpretation is done by a system, not by people. Which is pretty nice, because sometimes a diagnostician wants... the athlete to improve, and this pure interpretation falls away. The system says: you got better or worse. Hard facts. Which is great — and which is always an important learning for me as a coach. Okay, we have this data, what went wrong or what went particularly well? Did the training work the way I thought? Yeah, I see it that way. So you can always do it at home. The difference is of course we're not measuring directly. We don't have a spiro, we don't measure oxygen, no real oxygen uptake — we extrapolate it, which we can do very well. And the lactate — we simulate the lactate based on the watts or the watt performance of the athlete. That also works well. And we simply save ourselves the trip to the diagnostician. And then we can see the proportionality afterwards — how this performance has developed and which different hybrid engines were actually worked on. And this long-term comparison is the beautiful thing we see. And if you can do it every eight weeks, that's realistic to do. You don't go to diagnostics every eight weeks. A) the trip is usually too far, and B) it's also a cost issue.

Sebastian: Okay, I can hear from that — every eight weeks you'd also run a Powertest to see.

Björn: Yeah, so every eight to twelve weeks I have Powertests run. Or I can read key numbers from races and say, okay, here's what's happening with VO2max. Then I ideally have a 12-minute or 20-minute test done and look at how VO2max has developed. You can do that in our tool too. So every twelve weeks there's some form of check.

Sebastian: Yeah, and fundamentally — if I understand correctly — we're already in testing mode. There are two things that come to mind. One is: doing a test every twelve weeks means you can also detect measurable differences every twelve weeks and correspondingly need an adaptation of your training zones. If we train by watts as laypeople, in certain zones, that can... have effects within twelve weeks if I've trained well. Then I could already adjust my training zones — maybe train at different wattages to get another stimulus and train accordingly.

Björn: Yeah, and that's something you have to decide for yourself — or the coach does. At the start of the season I actually have tests run even more closely. We know that with professional athletes, performance drops dramatically if they do nothing for two weeks. Then I have them train really easy for three weeks first. Then we do the first test. We've already had a slight adaptation, and then we run a test four weeks later, because they get fit so quickly that it doesn't make sense to have such long intervals. Later, when this curve flattens out, the tests become a bit less frequent, and then you really only look at the nuances — how has this athlete improved or deteriorated. You have to decide for yourself — if I notice, oh, everything feels so much easier now, I'll run a test again, then I definitely have an adaptation. So you can achieve an adaptation in two weeks. You can also train mega hard for two weeks, take a week off, and then do a test — I'll definitely have changed my performance capability in some way.

Sebastian: One aspect I also wanted to mention — what differentiates the Powertest — I come from the aero side and I see again and again how strong the influence of a power meter is, also regarding measurement accuracy and variation between test days. If you alone swap a power meter, that's obviously a significant component. When I do the test with my own power meter and also control my training with this power meter, I have a very clear advantage — using the same measurement instrument for both testing and training control. Whereas if I do a test somewhere else, I'm not always doing that test on my own power meter, and there can be quite some differences. So you always have to ask yourself: where do you buy yourself which error. That's a great thing. You mentioned two terms. I want to quickly pick those up because those are the core concepts of the Powertest: VO2max and VLamax. Can you maybe relate those to aerobic and anaerobic metabolism? Many know those. Aerobic and anaerobic — everyone's probably heard those. And now you mentioned two new terms: VO2max and VLamax. Can you quickly connect them? Is there a relationship?

Björn: Yeah, there is. Actually, I wouldn't combine them at first. VO2max — the listeners probably know that a bit more precisely. To break it down very simply: VO2max is the horsepower you have as an athlete. The higher your VO2max, the better you are as an athlete. It's also called the gross criterion of endurance performance. Then you get these ominous numbers like 90 or something. Then you know, okay, he's got a big engine. And VLamax is basically the economy of this engine, to put it simply — so how much fuel does this engine burn? VLamax basically represents this counterpart — I'll call it the anaerobic part — how much energy is produced via this part. To be a bit more precise: VLamax, the maximum lactate production rate — V as a flow rate, La for lactate, and max, so the maximum lactate flow — shows how much energy this athlete can gain from glucose, from carbohydrates. So our fastest fuel. And VO2max is basically this economical metabolism. The aerobic metabolism. And both together is this total engine, the total drive that makes the tires roll. And bluntly said, mixed together, you get to a threshold power at some point. And that's composed of these two things.

Sebastian: And when you mentioned these two terms — VO2max, VLamax — I can also have those measured in a spirometry test or lactate step test, for example. Can you compare the values with the Powertest? Are they at roughly the same level? Does that match?

Björn: VLamax I have to calculate. There are specific tests for that. Above all, you need a specific calculation method to figure it out — especially VLamax. That matches very well. So VLamax can be calculated beautifully with our system. And VO2max too, because there are proportionalities in watt production — how much oxygen does my body need to produce one watt? And we can reproduce that very, very well.

Sebastian: Okay, I got that. The metabolic profile — my metabolic systems, how I put power down on the pedals — I can describe through VO2max and VLamax. A mixed engine. One that has the VO2max — fundamentally the size of the engine. And VLamax, which also says something about how high my carbohydrate consumption is, for example. And VLamax, the way you describe it, initially has a negative character for me, because it says I'm burning carbs with it. Does it also have something positive if I have a high VLamax?

Björn: It definitely has many advantages. First, of course — if I'm doing an Ironman, low carbohydrate consumption is ideal as a goal. Whether the path there only goes through a low VLamax — this training path — is another question. But when I have races where I have to accelerate a lot — road racing, cross-country racing — I need this ability of high lactate buildup. High lactate production rate means I have a high anaerobic capacity that gives me relatively much pop. To briefly explain: we have different muscle fiber types. We have different muscle fibers in our body — fast and slow. And the slow ones produce significantly less lactate. And the fast ones significantly more, to put it bluntly. Whoever has many fast muscle fibers also produces more lactate. When a 400-meter sprinter crosses the finish, lactate is pouring out of his ears. And when a marathon runner runs 400 meters, not much happens, because he just doesn't have those fibers. And that's why a high VLamax can be positive when I have races with short accelerations, maybe also only short races — a 4,000-meter individual pursuit or something. There I need this high performance capability.

Sebastian: That also sometimes explains — I know various triathletes, especially long-distance triathletes, know this — when they're out with a road cyclist who has... a higher VLamax than the triathletes, and the cyclists start playing on the climbs, accelerating — as someone who's bred to not burn carbs anymore, you're pretty screwed, I'd almost say, because they wreck you. All these accelerations, it's impossible. But if you then manage to keep your power continuously very high, you notice that the others start suffering.

Björn: The question is always: how do I achieve the goal — delivering a fast race, ideally. What parameters do I need for that? And we had this at the beginning. How do I design my performance composition? Do I maybe need a high VO2max for my sport? If I race criteriums, I don't want to stand at the start with a low VO2max. Maybe unless I have a super high VO2max and just ride away alone and no one comes after me, and I'm also aerodynamically top-tuned, then it might work. But every sport has a certain range of VO2max and VLamax that are ideal.

Sebastian: We're talking this whole time about VO2max and VLamax. Would you quickly throw out some values for VO2max? What does a hobby athlete have for VO2max? Relative to body weight. We're talking this whole time about VO2max relative to body weight. What's a normal hobby athlete variant?

Björn: What VO2max do they have? Varies a lot. So VO2max — we hadn't actually explained this yet. This isn't a flow rate, it's a volume. O2, clearly oxygen, and then the maximum uptake. A hobby athlete who does a cycling marathon and maybe a hobby triathlon has something like 50, maybe. And then correspondingly — that can also — and we come back to this — there are also people who have really low lactate production, who are totally economized. And they can get through a really good triathlon with a very low, with a really small engine. And quite reasonably, because they're totally economized. With a 0.2 lactate production. But I'd say, a 50 — you're reasonably fit and doing sport. At 60 it gets interesting. Then you have ambitious, really good athletes. And from 65 upward, you have athletes who are really good in competitions. 65, 70, 72 — there we have Bundesliga riders on the road, and everything at 75, 80 — there we really enter pro sport. At least in road cycling. In long distance, oxygen uptakes can be lower. You can achieve top results with a 68 and very low VLamax. What does a Tour de France winner have for VLamax? Definitely either a super high 70, like 79, and a very low VLamax. But tending toward an 80+ oxygen uptake and then a 0.3, 0.4, 0.35 lactate production rate.

Sebastian: Yeah, definitely. You've mentioned values that sound familiar to me because they also come from our website. You can read all that there — what we also say. And the example with a 50 oxygen uptake and a very low VLamax. That one has a threshold power of 300 watts. We calculated that to make it transparent. And we call that one the Marathoner, because he's very economized — 300 watts as threshold power. But we also have someone else, a Sprinter, who has a 60 oxygen uptake. You said that he's obviously already much better from the engine side, already entering amateur sport. But he has a very high lactate production rate — 0.8. And we're mentioning all these numbers so you can get a bit more familiar. So we try to mention the numbers more often so you get a better sense of them. And this one also has a threshold power of 300 watts. And that's really exciting because — if, for example, I train a ton and always have the feeling, man, I'm not progressing at all, and I have a 300-watt threshold power, and my training doesn't match anymore. This example really shows how differently performance — you called it hybrid engines or hybrid parts — can be composed. FTP is the same, but these individual components are completely different. And you can imagine: they probably have to train completely differently.

Björn: Yeah, definitely. Even if they have the same goal — let's not go too far from one doing different sports — they have the same goal, an Ironman, they have to train completely differently. For the Marathoner, you'd say, okay, to get a bit more happening at oxygen uptake, we might have to briefly un-economize you and train up your lactate production — which is a long path. I find that totally exciting.

Sebastian: I find that totally exciting, because I know that so many long-distance triathletes have probably over-economized their VLamax, and at a certain point you don't see further development. And maybe they're at the end of the line — VLamax dead end.

Björn: Yeah, exactly. And that's ultimately the limiter at the end of the day. Sport or training is also subject to trends. We chased the whole ketogenic diet, fasted training, and the like through all the media over the years. And that led to people definitely dialing down their VLamax a lot, because whoever goes without carbs... also loses the ability to produce proper energy. The body adapts — VLamax drops, but you might be robbing yourself of the ability to improve overall engine size. Then you only have a Lupo and you're making the Lupo even smaller. And the sprinter has the Porsche. And the Porsche you just tune a little and let it burn a little less fuel.

Sebastian: Okay, that makes the whole thing really exciting. So definitely consider becoming un-economized again so I can work on the size of my engine, and then economize myself in time before my main competitions to be more efficient again. I hope we've already gotten you a bit excited about the Powertest. And that's just a small excerpt of what you can look at. That's why we're now really moving to the exciting things. Added value — we've understood that. We can... train ourselves significantly better. Performance gains are significantly better. You also have the chance to check your performance state, also check your development, and then respond if needed. I mean — what's worse than training for a year and then realizing: okay, I haven't gotten better. It would've been nice to have realized a bit earlier that maybe that wasn't the right path for me and that I have to train differently. And you can't expect anyone out there to inherently know how someone should train if they don't have a metabolic profile. So it's really a great thing, top-notch. Then you simply have more levers to control your training and be successful. Because one of the things that's really fun in sport is getting better. And that motivates us all somehow. There are many ways to get better. But today we're talking about the metabolic profile. What do I need to do a Powertest, Björn?

Björn: The right motivation. That's right. We've already covered that. It's like an exam. You always have to give your best. You need a power meter. Calibrate it beforehand. You shouldn't have trained hard in the days before. You should have eaten enough carbs — really eaten well — so your performance reflects what you can do. And then it runs. You don't need more. And then these tests get done.

Sebastian: Okay, but by the way you describe it, if I fasted three days beforehand, that would have an effect on my body.

Björn: Yeah, definitely. But it does when you go to the spiro too. Sure. If I go to the spiro and I've eaten badly for three days, or too little, or lived low carb, then the spiro will reflect something that maybe isn't actually present if I were eating normally. Then my fat metabolism would suddenly have totally changed.

Sebastian: Yeah, and you have to understand — the model is developed so that someone arrives rested with full glycogen stores, and that's what the system is designed for. You can manipulate it, and you really shouldn't, because we want values that are reproducible, that we can work with long-term, and that provide added value. If I'm doing the Powertest — so you're saying I need a power meter, I shouldn't have trained hard, two or three days of preparation, eaten good carbs, and then the day comes, I want to do the Powertest, I have my power meter and let's say I want to do it outside. Now I get on my bike, have my power meter, I've eaten well, and I have a carb bottle with me. How do I run it now? Now I ride out on the bike and what do I do?

Björn: First I ride really, really easy to warm up. Really easy. So we have good saturation, oxygen saturation in the muscle. So warm up, plain and simple.

Sebastian: 30 to 45 minutes?

Björn: Yeah, exactly. Really easy. Then I stop briefly. Stop pedaling. Stand still for a moment. Then I do a sprint seated. All out, everything I've got. Seated though. For... 15 or 20 seconds, I don't have it in my head. Ten seconds. Only ten seconds, ah, very good. And then I coast a bit in between. I think 15 or 20 minutes or even 30.

Sebastian: We've got 'easy ride out' and 20 minutes. So you can hear from Björn's comment that it's not set in stone. One or two minutes more, that doesn't make a difference. I know you always want to do this very accurately — which I love — but there's some play possible. One to two minutes, 10% deviation — that doesn't do much.

Björn: Exactly, then I do this 4-minute test, ideally paced, at a speed I trust myself to hold for 4 minutes. You can always look — have I ridden something similar before? Check that, and then I ride. The first two and a half minutes I try to go a bit more conservatively, and then the last 90 seconds I really give everything I have. And then I've survived the first test day. Okay. And the next day I do the classic branch.

Sebastian: I have quick questions before you continue. Let me get my questions in. One question: why do I have to do this seated? Can't I do it standing? Standing I can put out much more power and would of course also have higher power values in my Powertest.

Björn: Does that make sense? No. I actually want to see what your leg muscles can do. And also, I want it weight-adjusted. I don't want you — I don't know, if you weigh 100 kilos — pushing your 100 kilos into it. Sure, your legs weigh something too. But I want it weight-adjusted. Ideally I ride the 4-minute test seated too, to be honest.

Sebastian: So ride the entire 4-minute test seated. Don't stand up. Okay, that's important because it reflects your performance much better than if you stood up. Rather do it seated, even if power values aren't as high, but the metabolic profile that's calculated matches much better with what we can actually do. And not with other things. Okay, understood. But the 4-minute test, I have another question. So 4 minutes means... I really beat myself up for those four minutes, I put out everything I can, and I try to do it as consistently as possible. You can get very theoretical about this, but basically. Let's say I've done a 4-minute test before. I know my power data roughly. Let's say I can ride 400 watts for four minutes. Purely hypothetically. Do I ride the first two and a half minutes a bit more than those 400 watts, if I know that number, or a bit less? I'd ride a bit less. 93%. 93%. And then, you said that's the first two and a half minutes, and if I can still do it, I'd try to mobilize everything I have left afterwards.

Björn: Yeah.

Sebastian: Okay, understood. And these four minutes are obviously a tough story. If I'm a triathlete, do I ride the four minutes in aero position?

Björn: Ideally yes, because if I ride my race in aero, then I should also know what my performance capability is in aero position. But if I train a lot on the road bike, then I should maybe do the test in my road bike position. That's when two tests on two different bikes make sense. So testing on both bikes to know on both bikes — okay, what's actually my capability on this bike and this bike.

Sebastian: Okay, and that's interesting because if I train a lot on the road bike, I could do the Powertest to check whether my training is working, how it's developing. On the other hand, I also need the Powertest because that's also one of the cool features. For example I can also do calculations — simulations — of what power I can ride a certain time. So it'd be interesting to make predictions for a race, what power I can take to the race. So also for that, the Powertest on the time trial bike would be interesting. Is there a measurable difference between road position and time trial bike?

Björn: We all know there is, yeah. Road racers know this much better than triathletes, because they're not on their time trial bike as often, and they think, oh, 400 watts threshold, I'll ride that on my time trial bike too. And then they end up with 360 watts at the end and suddenly notice — ah, it's a completely different position that I haven't trained much in. Maybe I need to check my performance there.

Sebastian: Okay, so we're talking 10% power drop between normal seating position and an aero position on the time trial bike.

Björn: Yeah, that can happen if I'm not adapted, and if the aero position is maybe too extreme that I restrict my biomechanical performance so strongly to get an aerodynamic advantage. I should absolutely know that.

Sebastian: Yeah, the cool thing is — theoretically with the Powertest and our Aerotest, you can calculate it. You can really consider: do a Powertest in an aero position, do an Aerotest along with it, and you could also switch and figure out what's actually the faster seating position in the race.

Björn: Yeah, where do I get the biggest... biggest bang for the buck? Where do I have the biggest added value? That's obviously a cool thing.

Sebastian: Okay, good. I understood that. So that's the first test day. I know — easy for three days beforehand, eat good carbs, go into the test rested. Then I have 30 to 45 minutes easy warm-up. Then I stop, do the 10-second sprint seated. After that I ride easy some more, and then I run the 4-minute all-out test. Do you have any hints? I've never done one before. Let's say I've never done a 4-minute test. I have no idea. But I know my threshold. Let's say I have this threshold of 300 watts. Would you have a tip for how I should start pacing it?

Björn: That's a bit trickier. I'd say: if I put down a good sprint — what does a good sprint mean, you have to ask yourself — then I'd tend to pace a bit higher. If I notice I'm barely moving, then I shouldn't ride much more than my threshold power, possibly. We also have a great calculation for this on our platform.

Sebastian: I have this Marathoner and we have the Sprinter, and they both have 300 watts threshold. Now the trick is: when they ride four minutes, the Marathoner can ride 355 watts, roughly. And the Sprinter can ride 435 watts. He can ride a solid 80 watts more. And you already see a big difference there. Makes it a bit trickier too. The idea would be to start somewhere in the middle. And if you do the test for the first time as a Marathoner and go in at 400 watts, you'll suffer.

Björn: But that's the learning curve you have the first time. Right, definitely. And the nice thing about the Powertest is that we can basically practice it for a month. So I buy my Powertest and if I see, okay, that test was really crap. I can do better. Or a car came by, something happened here, something happened there. Then I can do it again a few days later. Especially the 4-minute test doesn't have that huge impact on the body. You can do that again two days later. Yeah, okay. Okay, then we have... do you want to quickly say something? Sure, gladly. Where do I run the test? We have tons of athletes who say, hey, I ride this on the mountain. I can do it better there. I have some pressure on the pedals and I just notice, okay, I have to push. I ride more watts. But do I also ride this in the race? Again the question: what can I ride on the mountain, what can I ride on the flat?

Sebastian: Yeah, there's a difference. So try to orient it more toward where your race is. And if you're a time trialist with a flat profile or an Ironman athlete and you're not starting at Lanzarote, then a test on the flat might make more sense. If I'm a mountain bike pro who... spends a lot of time climbing the mountain, it might make sense to do it on the mountain. Exactly. Okay, good. Then we're through the first day. On the second day, what do I do?

Björn: There we have the classic 20-minute test. We ride easy, easy, easy to warm up.

Sebastian: We have 30 minutes here. Correct. Then we have a 5-minute test in there too, at 80% of the max step power from the Powertest on Day 1. What does that mean?

Björn: That means I ride 80% of the power I had in the 4-minute test. Ah yeah, okay. And step power — we'll come back to that, because we also have an indoor test variant.

Sebastian: Ah, yeah, okay, we'll explain that afterwards. So I ride another 5 minutes. Why do I do that? Is it important? Can I just leave it out? Or would it be bad to leave it out?

Björn: No, I'd definitely do it. First, it gives you a bit of a feel for... okay, how does this feel? Is it way too much? The muscle has already built up some lactate. As a result, the different muscle fibers that build lactate but also break down lactate come back into slight breakdown mode. And when you then do the test, your muscle is practically prepared for the test. Okay.

Sebastian: Then I should ride easy for another 15 minutes and then this 20-minute test comes. What do I do in those 20 minutes?

Björn: Exactly, so there too I'd start a bit more conservatively, similar to the 4-minute test. I ride the first 12 or maybe 15 minutes at a target power — a few watts less, 5 watts less than I actually want to ride. And then I ride the last five or eight minutes a bit more, so that we get faster toward the end — a negative split, pulling the speed up at the end. And please also ride it seated, ideally everything.

Sebastian: You always phrase this very nicely — 'ideally.' Ride it seated. So don't stand up, that changes the values, changes the test, and that's not what you want to measure. It's simply the mirror — that's what you can do on that day. And I know some pro triathletes get really stressed by a test like that. Aside from doing it in a lab, a lactate step test, and you have to drive there, pay money, and have the hassle of getting there — that only increases the pressure. And with a pro athlete I can imagine — okay, the added value of having something checked in a lab is there. But as an amateur athlete, for example. To have such high pressure on top of all the challenges you usually have because you're not a pro — you also somehow earn money normally and are out and about — going into such high pressure, I know quite a few suffer from that. What's positive is you can always just postpone it. What about — so I do the 4-minute test on the first day, on the second day I don't feel so good. Can I do the 20-minute test on the third day?

Björn: Sure, it has to be reasonably close together. We sometimes have athletes — or I have athletes who say, hey, here, this is my best 4-minute value. And then I have a 20-minute test here that was ridden 4 months later. That's no longer meaningful. Maybe incredibly much happened in those 4 months. Lactate production went way down or VO2max changed somehow. So I want to have an image of the performance at that point in time. And I want to represent both engines. And it should be reasonably close together. In a week not much happens. In two weeks also not much happens. Should be reasonably close.

Sebastian: So ideally somehow... the two days back to back, you're organized and done and can dedicate yourself to other things. But if the shoe pinches and you really can't motivate yourself the next day, or something comes up, do it a day later.

Björn: I also have many athletes who say, listen, I can only ride the 20-minute test on the weekend, because that's when I have this stretch, and there's less traffic on Saturday, and the road is great. So we usually ride the 4-minute test on a Thursday. Wow. Friday off and then we ride the 20-minute on the weekend. And the advantage is I can ride long training after. I can do the 20-minute test and then still go train for three hours or four hours, depending.

Sebastian: Okay, good. I've got that so far. One more question. Indoor there's also the option to do it on the bike ergometer. How do I do that?

Björn: For that we created our nice protocol that you can read up on. Essentially you mount your bike on the trainer and we ride easy to warm up again. 20 minutes, I think. Yeah, 20, 30 minutes, but really easy. That's very, very important. Really, really easy. Then we have another 10-second seated sprint. Then we ride easy out again. 10 minutes, 12 minutes. Remember — you should always cool yourself, because body core temperature has a strong influence on such indoor tests. And then you start a step test, depending on body weight and performance. Maybe I start at 60 watts, maybe at 120 watts. And every minute I raise the power by 20 watts. And do that until I can't anymore. Then it's over. The nice thing about this value — to come back to the 4-minute test — the values I can ride at the end of this test, the last minute, maybe the last 2 minutes, those can be used as a rough benchmark for the outdoor test variant. For the 4 minutes I can ride outdoors, right? Yeah, exactly.

Sebastian: So they're roughly in range. Yeah. Okay, that's actually the only difference. The ramp is of course great because it guides you to your performance max. Whereas with the 4-minute test, you've already heard, I need a bit of know-how about my own performance and have to be able to pace it, whereas with this step test I get specifically blown up. Because at some point I can't anymore. And that has the nice advantage that I'm structured upward and don't have to think so much about my pacing. I have to with the 4-minute test. When I then, okay, only day 1 is actually different. On day 2 I now do the 20-minute test, which I also do on the bike ergometer. And important — as you said, if I understood correctly — cool yourself well, right?

Björn: Mega cooling, really, really important. And you can also leave a day between — the step test can be tough. And easy warm-up, cool, cool, cool, cool — really important. And it's like a test on the flat. You can't forget that. It's like a test on the flat. And there are some athletes who say, I always ride the 20 on the mountain and I always get higher values. Yeah, if they rode a similar test on the flat, they might get similar values. And it's also always a question of motivation. And one thing you can't forget — on the trainer, just due to heat buildup, we always have slight power losses. And there we come back to this area. Maybe I should use different power values on the trainer than the values I ride outside.

Sebastian: Okay, because my cooling is worse. Exactly. It can definitely be that I get different power data on the indoor trainer. But if you also want to train indoors — so I'd take a certain segment where I just do indoor training and indoor sport, and I test myself indoors. And when I go outside, I do an outdoor test right away to see where I stand outdoors. And then I test outdoors further and shift my training.

Björn: We see big differences especially with large, heavy athletes who generate significantly more heat. They always have a bit more problems indoors. And outdoors they ride really well.

Sebastian: The engine just overheats faster. That's partly related to the surface area.

Björn: Surface-to-mass ratio is a bit different, worse. Those who are small and light generally have it a bit easier indoors.

Sebastian: Okay. Good, now I've done the test. Now I go to the website afasteryou.com, I've bought a Powertest. A Power Month, I can upload Powertests for a month as I want. I can also use the Aerotest, just that too at this point. And upload the files, get fully automated analysis. And now I first see four key values. We've already talked about them. I see VO2max. I see VLamax. We're also planning a classification soon so you have a better picture to categorize these values a bit, so you have a better sense of whether you're at pro level etc. Now I see my threshold power — that's this theoretical value over one hour — and I see the Fatmax value. We haven't talked about that yet. What is Fatmax? For our Marathoner we talked about, he'd have a Fatmax of around 220 watts. What does he do with this Fatmax value? What's special about Fatmax?

Björn: So with Fatmax we have — now it gets complicated — no, I won't use that word. Okay, good, good, make it simple, as simple as possible. Yeah, Fatmax is basically the zone where the body uses lactate best. The maximum pyruvate deficit, sorry. You can forget that again. And that makes it a very, very exciting training zone. For a Sprinter, he can spend a very long time in this zone. For a fully trained Marathon rider with a high oxygen uptake, this can almost turn into intervals because it's quite a strenuous zone. But here we have an ideal training zone for base adaptation. Okay.

Sebastian: So this is the perfect zone for base training if I understood right. But if I'm really well trained, I can't ride in this Fatmax zone the whole time, because the power might be too high.

Björn: Yeah, exactly. So with — let's say — a well-trained good athlete, 75 oxygen uptake, 0.4 lactate production, they can — depending on weight — ride 280, 300 watts Fatmax. And that's already strenuous for them, but they ride that in intervals. For others that's threshold power. Exactly, they ride three times 45 minutes. And I mean, cruising 300 watts across the flat — they ride 38, 39 km/h the whole time. That's already heavy. And of course you have to eat. And those are road cyclists you just mentioned.

Sebastian: Because if those were time trialists — and we have some too — suddenly they're hammering 50 km/h around, somewhat, then it'd be really unpleasant.

Björn: Exactly. So base and Fatmax is that zone where we have the best adaptations for endurance capability of VO2max. And you can ride tons of that.

Sebastian: Yeah, that's a great... We'll come back to it, because we want to briefly talk about the training zones shortly. But those are the first four values. And classically you have threshold power. As I said, that's a theoretical value you can't necessarily control your training with. For that we have VO2max, VLamax, and threshold power — as orientation for where you — if you want to compare with others, what FTP is. Another nice value that can help represent your overall performance capability a bit — already a first approximation. VO2max, VLamax is then just much more precise. And the Fatmax value, I've understood, is a great zone to train my base endurance. I just have to be careful that if I'm already very well trained, the zone actually can't be ridden continuously anymore, but more specifically in intervals.

Björn: And as I said, there we have very high lactate metabolism. That's also a zone where I say, okay, I'm riding hard intervals now, if I'm doing interval training, and then I continue in the Fatmax zone to use lactate.

Sebastian: Okay, so that's an advanced mode you're mentioning here. We'll certainly do an episode where we might talk only about lactate. That might get a bit nerdy, but also to get to the bottom of things. But we want to try — in the time we have, we've been talking quite a while — to get more to the points you can see in the results. There's a representation of the moving average power over time. That's simply the moving average, sliding power over time displayed. You might also know this from Strava. And there I see my power again — just so you have an idea of what you've done. The next graph is my energy consumption over power. If you don't look at it more closely, it's first just pretty curves going along. The x-axis is basically power, and the y-axis is consumption displayed in grams per hour. And things like fats, carbohydrates, and proteins are shown. If I look at this purely mathematically — x-axis power, my output, and y-axis consumption, how much I'm burning — you can definitely see, if you're on the description page, that the carb consumption between the Marathoner and the Sprinter is really different. And — one thing — if you're in a training camp, you can think about how many carbs you're burning per day and whether it might make sense to refuel them. For example, how do you use this information, this curve? Do you use it in your training? Do you calculate things with it?

Björn: Yeah, this is a really decisive point, this curve. I use the curve to give athletes specific gram recommendations. We work with people, and we also work with many dogmas. We have to face these dogmas — that eating less is important, only that way will I get thin and become performant. That's nonsense. If I want adaptation, maybe I should also supply what I'm consuming. And you can specifically tell athletes, okay, this many grams of carbs — especially for long sessions — it makes sense to specifically tell them the carb intake. And also, when you hear the word Fatmax, you think, ha, I'm only burning fats. No, that's nonsense. Here too we always have an energy mix from different substances, especially carbs and fats. And well-trained athletes might already burn significant carbs even in Fatmax. In our example here we see the Marathoner already burns 60 grams in his Fatmax. So even if he's riding easy, he has to eat the whole time. No, the Sprinter — sorry, and the Marathoner burns less. And you see that often, as you mentioned at the beginning. When the triathlete is out with road cyclists and they're pushing the whole time, but the cyclists forget to eat, then the triathlete will eventually say, okay, two, two and a half, three more hours, let's ride 35 the whole time. And then they'll suffer quite a bit if they don't eat lots of Snickers along the way.

Sebastian: Yeah, so that gives a really super insight into how many carbs I'm actually consuming. And as a little hint for training control — and this is an advanced topic — but maybe you want to say something briefly about it. If I want to increase my VO2max — you've heard now, you should increase VO2max — does that work by, for example, supplying myself with fewer carbs? Do I manage to increase VO2max that way? If I do high-intensity intervals but just don't eat carbs and try to only do complex carbs during training — no carbs — does that have an effect?

Björn: If it's really, really, really short, maybe. I mean, if we're just talking about trainer training over a long time — no. VLamax will drop, and VO2max will most likely also go into a decline. So that won't work. Fundamentally, I wouldn't do it. And you also feel lousy, because this glycolytic performance that comes from carbs — if I don't feed it, if I don't push carbs, I simply lack them.

Sebastian: And if I want to work on this high-intensity zone to make this engine big, I need the carbs, right?

Björn: Yeah, definitely.

Sebastian: Okay, good. That means you get an insight into the carb consumption I have. And I can think — if I do a ride outside and I ride at 200 watts the whole time, check how much carb consumption you actually have. And depending on what you want — if I understand correctly, you deal neutrally with this carb consumption. So what you burn, you take in. And — or if I specifically want to lower VO2max, maybe I take in a bit less carbs. And if I want to be more in the zone of increasing my VO2max, then I eat maybe a bit more carbs than what I'm burning. just to be safe, because if I'm riding 200 watts, maybe I'm not always at 200, maybe I ride a bit more, and then the others come by and I have to show what I can do, and I don't want to look like an idiot. Okay, I got that. Then I've understood — this is my energy consumption, I get a really good insight, and I also have the opportunity to plan my races. And we'll keep developing the platform and want to offer you the best possible. Stay tuned. We'll offer you real added value in the future, but we'll tease that at another time. Next diagram: maximum power over time. There's a representation given, and here you can also see different values — if we go back to the description page, there are the Sprinter and Marathoner, and you see, as I mentioned before, over this short time the Sprinter can deliver significantly more power. I can — if I understand correctly — plan a bit what power I can ride over a certain distance, right?

Björn: Yeah, absolutely. I have to say, this graph is a model, a theoretical model limited to the fact that I only have a certain amount of carbs available, which I need to sustain these high powers. This fatigue, or maintaining performance so high, has tons of factors. Body core temperature, how much I've drunk, daily form, blood flow, motivation. We have a multi-factorial system.

Sebastian: Maybe also the stress I had just before. What I think is important to take away — and maybe you'll agree — is that I probably can't get more than this diagram, right?

Björn: No, absolutely not. No chance. It shows above all — and this is the beautiful part — if we now have this analysis as an individual athlete, I see that with higher carb intake I can also sustain my power longer. And that's what matters most to me. Sensitizing athletes that high intake also moves you forward. In the past they said 60 grams per hour. What the liver can practically release under load, I also supply. Then at some point we got to 90 grams. Jeukendrup's study. And now we're experimenting with significantly higher intakes. 110, 120 grams. The athletes, the pros I coach, we take in 120 grams of carbs per hour in the race. Especially in stage races. And that's still not the amount they actually burn in the race. We always work with a deficit. And that's hopefully covered by liver glycogen and what we stored in the muscle beforehand. That's the planning — the tricky part.

Sebastian: So how much do I want to deplete myself? If I only ride the road bike or only mountain bike, I can say I blow out everything. I need to road bike. I don't need anything more. For triathletes it's more demanding — they have to think about how to go into the run. Do I want to have my carbs completely depleted and then not again during the run? Or does it make more sense to save carbs, maybe not use everything on the bike, and then run a fantastic marathon? That can also be a perspective. We'll maybe do an episode on that too — what pacing strategies could be best practice. But that goes beyond the introduction to the Powertest. I just want to mention one number at this point. A Marathoner with a 0.2 VLamax and 50 oxygen uptake, if he doesn't take in carbs but uses all his stores, can ride roughly 200 watts for 5 hours — theoretically, as a maximum upper bound. But if he takes in 90 grams of carbs, he can already take in almost 270 watts. So almost 70 watts more, simply over 5 hours, because I strictly take in 90 grams of carbs per hour from the start. You see the enormous effect of carbs, and it's also worthwhile to think about... a carb you tolerate well — you can intensively engage with this, how do I take in my carbs, how do I manage to take in many carbs. And we can also do a whole episode on that — how to design your strategy — because you see there's tons of potential just from taking in your carbs.

Björn: Okay, really decisive point. Really test, test, test. Everyone reacts a bit differently to carbs. We just saw that with some athletes. We measured glucose a bit and saw how athletes respond to different carb sources. That's always different. But we'll definitely do our own episode on that. There are carbs that are more tolerable. There are carbs that aren't more tolerable. So we'll do it calmly. But fundamentally, carbs are the fast fuel. Take in lots if I want high performance. Simple as that.

Sebastian: Okay, let's move to the next analysis the Powertest offers. Those are the training zones. Obviously, we all know training zones. We have very classically — let me see what training zones we have: Recovery, Base, Fatmax, Tempo, Sweet Spot — you know that often — threshold. We also offer Maximum Lactate Steady State. We'll maybe cover that separately. That goes beyond the scope since we've been going for a while. We have VO2max 90, VO2max. The zones are given to you. You have the power factors you can see there. We also displayed for you the carb consumption, so you have an idea of how many carbs you're burning, and also how your fats look. And again for the pros among you — also the torques. You can do a lot with that too. And maybe we'll do an episode on torque — what effects it has on muscles, and you mentioned it — muscle fiber types, we specifically address, can control that even more. When you train with your athletes, what are your favorites among these training zones? Sure, you probably use all of them sometimes, but can you say which training zones you use most often?

Björn: What's most practical — and that's usually Base and Fatmax. That's where the music is. There's this 80-20 or 90-10 rule, then polarized training as it's nicely called, but there's not full truth behind that either — but we should spend a lot of time in these zones. So we ride a lot of Base and a lot in VO2max or VO2max 90. And if we want economization, i.e. lower VLamax before a competition — so eight weeks beforehand — then I can work in other zones, like the Tempo zone or Sweet Spot zone, simply to... have high energy throughput, maybe not fully refuel, to stimulate lactate production rate.

Sebastian: Okay, so I'm an athlete with high VLamax for example, but I want to do a long-distance race or a very long race. Then I'd see that two or three months before my main competition I specifically start lowering my VLamax, right? If I understand correctly. Yeah. I'd also work with carbs — maybe supply a bit less than what I'm burning, but still handle it sensitively and not push myself into overtraining. But if I'm someone with a very low VLamax and my competitions are still relatively far away, then I start becoming less economical, do VO2max in the tub, supply myself well with carbs, and maybe also use Fatmax, right?

Björn: Which I always use, fundamentally. And for someone who's really economical, you also have to think outside the box. You have to do completely different things, like classic strength training, hypertrophy training, long breaks in between, to stimulate these FT2 glycolytic fibers that burn a lot of carbs.

Sebastian: You mean those who are already very economical?

Björn: Yeah, exactly. Who have a very low VLamax? Exactly. To have an effect on VO2max. You can go really deep here. There are studies by David Bishop on this. But that would blow the scope completely. Fundamentally, higher VLamax usually means a good stimulus on VO2max.

Sebastian: In the PDF report we provide, there are also some key facts about these individual training zones — how you can use them and what effect they have on VO2max, VLamax, and how you can handle it with carbs. We want — at this point we can do a whole episode just on training zones and how to use them cleverly to control your training. Usually your coaches know this, and otherwise look at the PDF document again and follow our podcast. We'll give more on this. Our platform will also keep developing and we'll progressively offer you more information and more help to control your training. Now we come to a graph that generates the most follow-up questions, but also displays the most know-how. And that's my training times per week. Can you briefly explain how to interpret this diagram?

Björn: Yeah, so fundamentally — we should've taken this step much earlier. Fundamentally: what does what we're doing here actually rest on? These metabolic simulations are based above all on the work of Professor Mader from the Sport University of Cologne. He provided the foundation, and we've refined everything. Thomas Hauser wrote his doctoral thesis on this. And now with these training zones, it's mainly about how much time I can ideally spend in a zone to get good training adaptation. That's what it says. Measured by energy consumption. Calculated from energy consumption. And Alois Mader also did a lot on this, though not everything is just Mader — there's also David Bishop and George Brooks. And that shows how much time I should ideally spend in various zones to achieve adaptation. And we see there: we have minimum and maximum. That's calculated based on the athlete's performance capability. Let's say we go into this Base zone. And we see a light blue and a dark blue bar, and the light blue bar shows me: okay, this athlete should spend 17 hours and then he already has a really good adaptation. But shouldn't do more than 21 hours. That's already really a lot — if he's doing a pure base block. Pure base block, yeah. But it also shows — when people go to a training camp and blast 30 hours or so, that can already be way too much. They forget, and come back saying, after three days I'll ride further. They ride themselves permanently into slight overtraining because they most likely can't supply enough energy anymore. We have this problem often in the pro realm. And then we come to the next zones. There we see again this light blue and dark blue bar, always saying the minimum base time and maximum base time. And next to it is the interval zone. Now we have a Fatmax zone here, and next to it says how long is the ideal time this athlete should ride in the Fatmax zone.

Sebastian: And that's meant per week, so that's not a single session — like I should ride seven hours Fatmax here — it's cumulative time, everything added up over a week, what I should train in that zone. Max too, right?

Björn: Right, exactly, absolutely. And it goes on like that. So the base time plus the interval time is the total time I should maximally spend in that zone. And then next week I can continue training, as long as I always eat enough. If I do more, I need more recovery.

Sebastian: Yeah, okay. I can also see, if I only do Base, I can do a lot of Base. But if I switch to Fatmax, my Base time becomes less. But I'm also doing more now — I get to specifically train Fatmax. And overall my training time will become a bit less than if I only did base endurance, because I also train a bit more intensely. Yeah, clearly. And then I can see — okay, Fatmax — if I want to train Speed Sport because, for example, I want to lower my VLamax, then I can specifically train less in this Speed Sport zone. So not as much time as in the Fatmax zone, because it gets more intense. Less time when going to Maximum Lactate Steady State, whatever that is, then even less time in that zone. Threshold I see — we all know it — training near threshold, lowering VLamax for example. The expert would say it depends, depends. How I handle my carbs. But you can lower threshold, if I understand correctly, if you also handle carb intake cleverly. I see time going down further there. And VO2max 90% goes down further. And VO2max — if I'm really doing this high-intensity zone — I have even less time. Now what's totally exciting about this — if I see the Marathoner versus Sprinter again — the Sprinter can simply train much more time in the VO2max zone. And that's another crux. Now I'm someone who possibly has a low VO2max. Low VO2max. And now I can train even less time in VO2max. That makes it even harder for me to get out of that.

Björn: Exactly right. That's why we created this 90% VO2max zone. You can also get creative there. Our body isn't such that we just ride at 360 watts to reach 90% — if we assume 400 watts — and then my muscle is immediately there and at 90%. No, we only have a power output that's now at 90%. But our body needs time to get there. You could also say, okay, I prime it — I go in super hard and then ride at 90%. We always see that nicely in heart rate. But we fundamentally see that the Marathoner has to deliver less power — or should deliver less power — to improve his oxygen uptake. That has a bit to do with FT2 fibers, fast muscle fibers under high loads, having better endurance adaptation. We can get into that at some point — AMPK and so on. And that's not quite as present in the Marathoners because they simply have a bit fewer of these fast phases. They get to train a bit slower. On the other hand, you can't forget — the Marathoner's threshold power is at 300 watts, and his VO2max — well, only at 360 or maybe even 340 — he's already very close. When he rides his threshold power, he's already very close to VO2max. He just has to do a bit more. And we generally say anything at 90% VO2max, we have a good adaptation. And the Sprinter is the crass opposite — he can spend really much time in these zones, especially in intervals, like 30-30, 30 seconds hard, 30 seconds easy.

Sebastian: To classify this quickly — I'm a Sprinter with VLamax greater than 0.6. So 0.7, 0.8, then I'm a Sprinter, I can train this high-intensity, and can also stimulate my VO2max super well. If I'm more the long-distance triathlete, with a VLamax maybe under 0.4, I'd more use this VO2max 90%, because I can invest more time there and work more specifically.

Björn: A bit above threshold.

Sebastian: A bit above threshold. And the one who's more the Sprinter with high VLamax — he can also do the full 100% VO2max, which is even higher — he can set a really crass stimulus there and has the chance to develop his VO2max better and faster than the long-distance athlete.

Björn: Yeah, definitely. And there we see again the pure proportionality. 300 watts threshold for the Sprinter, say, but maybe 400 watts VO2max. We see, that's a 100-watt difference. If he trains briefly above threshold, not much happens at VO2max because the stimulus just isn't given. These proportionalities alone show: the Marathoner needs a bit more than threshold to have stimulus on VO2max. The Sprinter needs significantly more to have a good stimulus.

Sebastian: But overall has a bigger stimulus on VO2max and can also develop it faster.

Björn: And it doesn't hurt them. They can ride really, really many hard intervals.

Sebastian: Okay, we haven't solved the mystery yet of how to design training weeks before your race. We've given some hints, and fundamentally I understand this diagram: this is the min-max of what I'm allowed to train in the various zones. If I train the minimum listed there, will I get better or worse? Or is that enough? Or am I preserving my state?

Björn: That depends a bit on the athlete's starting point. If I'm a highly trained athlete, I preserve it. If I do minimum base, I preserve it. Or maintain it somewhat. If I'm not that good anyway, something will already happen. Then I definitely have an adaptation.

Sebastian: Okay, so fundamentally I have an idea now of what I can train per week. Min-max zones. You just said — in the min zone, preservation; in high-performance and amateur zones, I already get an adaptation. If I do the maximum time there, I most likely get a performance increase. Do I run the risk of overtraining?

Björn: If I eat enough, no. And if my baseline stress level in my life is in normal range, then yes. Also not. Then it fits. It's always designed so I can cope with it well. It's a lot, but if all other stressors are under control — screaming kids, stress at work and so on — then... If I'm a triathlete, this is an analysis that applies to cycling.

Sebastian: Can I also use these hours for my running? Can I say these volumes fit approximately? Or can I train more or less then?

Björn: Less. Less training. Just from the impact on the whole musculoskeletal system, I can't run 21 hours.

Sebastian: Okay, so if you do this test on the bike, and you say — I'll spend 15 hours in Fatmax — that only applies to cycling. You have to deduct something if you convert part of this training time to running.

Björn: That's our project we'll tackle soon — developing a new test that also works for running. And there we'll also provide the times that can be run. Exactly, great. Yeah, that'd be a good thing. Looking forward to it. Fundamentally — to sensitize athletes again, I find this really important — we're talking about watts the whole time. I'm a big watts fan, but that's always just the input we're putting on the pedals. And the output — what happens to our body — the only measurement instrument we have for that right now is heart rate. So always look at that. If I — as I just mentioned — go into an interval very hard, and then maybe drop back to my threshold power, my heart rate is still strongly elevated. That means I still have a high stimulus on VO2max. Always keep that in mind. Look at your heart rate. If you see it's super high in some zones, we definitely also have some stimulus on VO2max.

Sebastian: Those are the intervals we also specify in the VO2max zone: 30-30 and 60-60. That's high intensity for one minute, one minute easy. Heart rate doesn't drop at all in that time. So I have — Tabata also did studies on that — there's still an effect. But there we're already going deeper.

Björn: But what I want to say — always look at what your body says, very important. And if I see heart rate goes through the roof, I definitely already have some adaptation on VO2max.

Sebastian: We want to help with that in the future and will also analyze relationships better and display them. So stay tuned.

Björn: Which intervals are ideal for my rider type? How long should the pause be? How long should the individual interval be? It'll all come. Okay, we have that.

Sebastian: And now it's on the website, and there's a PDF document, and I have a representation of my current state. With the Powertests — if I now understand correctly — I really have the chance to get my metabolic profile, my stamp. How is my performance composed? For example, how are my training zones, how much time can I spend in these training zones — I have a real chance to improve my training, improve my performance, prevent overtraining, understand how many carbs I'm burning, and steer my performance long-term and really see that I develop long-term. Often it's a bit underestimated what's possible in three, four, five years. And sometimes what you see within a year is too little. And what's possible within five years is significantly more than you think.

Björn: Continuity is the key. We don't learn stochastics in first grade — that builds up over twelve years.

Sebastian: Yeah, so we hope — with this somewhat longer podcast, but there are lots of exciting topics we find super exciting ourselves, where we've invested a lot of time and effort to build these algorithms and models — we've used science to build this. Björn has collected tons of experience in various performance diagnostics labs and built a lot. So there's really a lot going on, many possibilities you have with this. We hope we could bring this whole topic closer to you, explain the added value. And also for us — from the conversation many topics came up that still need to be addressed, which we can certainly explain in a podcast. But we mainly want to display the core values on the platform so you can steer your training with as few values, as few parameters as possible. And for low-budget training — having high-end training — yeah, that's our goal, and we have that with the Aerotest and with the Powertest, and we'll definitely do a podcast — which I personally find totally exciting right now — on how to use the training zones and times to prepare for my race or season. What should I do? How do I progress?

Björn: Yeah, we'll definitely do that. We've kept it really basic now — and it's already almost an hour and a half, I see — rode through it once. If we also covered the background on the studies and individual calculations, which still contain so, so much, it would blow the scope completely. Maybe we'll do a real geek episode. We'll certainly invite guests who have more to say on that. But ultimately we've lifted scientific models onto a platform that give you the option to calculate these things. There's a lot of research behind this that we've taken and brought together. And with it, you can design world-class training, at least for some.

Sebastian: And maybe to close — for questions that may have come up from this podcast, or where you want detailed explanations or want a podcast on something, for suggestions and criticism — always happy to hear. We live for it. We try to make it better. And this is now our third podcast.

Björn: No, fourth.

Sebastian: Fourth podcast. Yeah, we try to make it better. So tell us what we can do better and we'll practice. So. Super. Cool. Thanks Björn.

Björn: Thanks Sebastian.

Sebastian: Had fun.

Björn: And then let's think about what to do next time.

Sebastian: Let's do that. And on that note, till next time. I hope you had fun. Bye. See you. Ciao, ciao.