Ceci est A Faster You

Björn: So, yeah, welcome. This is our first podcast from Afasteryou. Sebastian and I figured it's about time we tell people a bit about who we are and what we do. So the first episode is all about: who are we, what do we do? Because in Germany especially, we have this phenomenon that apparently not that many people know us. So let's just start casually. Maybe simply — Sebastian, how we met.

Sebastian: Yeah, first of all I'm obviously really excited that we're starting our first podcast and I think we've got some pretty interesting stuff to share. And I think it's great that we start by maybe telling people how we actually met, who we are and what we've been up to. And then we'll quickly name a few people who've become very successful with us. And maybe that'll be interesting for one or two of you out there. And later we'll definitely talk more about how our technologies and software and capabilities actually work in practice. What was really interesting is — this was a few years ago now — I did one of the very first aero tests here in Schleswig-Holstein. That was with Kai Dobert. A really good, very good bike fitter. He also wrote a book about bike fitting. I got to know him. He always found aero testing really interesting. And I went out with him in Kiel to do aero testing and got to test right away with some really strong guys here in Schleswig-Holstein — Gregor Hubs, Jordan Davis, and Jan Oellerich. There are some real rockets up here in the north, you have to say. And of course at the beginning there was always a bit of skepticism about aero testing, especially back then. But when we saw really stable CdA values and could clearly show the differences, the ice was broken pretty quickly for the guys. And we tested a lot of things, tried out helmets and looked for ways the guys could get even faster. And it was already quite interesting to see that you really couldn't say one helmet made everyone faster — there were actually different solutions for different riders. And as it turned out, Jan Oellerich was so excited about it that he got his old coach involved — as far as I understood at that point. And told him about what was going on. Because his old coach turned out to be none other than Björn, who we're sitting here in the podcast with today. So that was roughly how we first got connected. Björn then reached out through Jan and contacted me. Jan had already told me. that Björn was quite special. And I got to confirm that later on. We then arranged to meet at the Eurobike and that's where we sat down together for the first time. We were there with our team, Björn was there with his team, and we exchanged ideas about the possibilities and how aero testing works and what the future could look like. Björn recognized pretty quickly that it would be a significant advantage for him and his riders if he tested aerodynamics. And what always stood out about him is that he didn't just see it as relevant for time trials, but especially for road racing too. And potentially for his mountain bike guys as well. And so when we were at Eurobike, I got to take Björn along and show him — we had no less than... Anja Berenek, who we actually tested with right there. She was my very first aero test subject the year before. She was sent by Fritz Buchstaller, who's also a fantastic bike fitter — I've been to him many times in my life, learned a ton from him. Great guy. And Anja was always with Fritz too, and I had already told Fritz about the software I'd developed, so that's how it all came together. We did things more professionally with aero testing then, and we tested with Anja, who went on to ride the second-fastest bike split at Hawaii, behind Daniela Ryf, and finished fourth. And on that day we tested with her again. That's how the ice gradually broke between Björn and me too. We exchanged ideas more and more. Björn even coached me for a while, which I thought was really great — I had no time but still wanted to do triathlon. Björn found ways to get me there, and I quickly realized that Björn really knows his stuff. He invested a huge amount of his time into really getting to the bottom of the metabolic profile theoretically and being able to apply it practically. And through our conversations, we came to the idea that it would be a great addition to Afasteryou if we integrated the metabolic profile. And after he'd been a coach and I'd seen his competence firsthand, we launched the Powertest last year. And since then we've been working together on Afasteryou — that's the story from my side of how I met Björn. And before I bore you all to death here and can't finish my monologue, maybe Björn can tell you how he experienced things from his side.

Björn: Coached is always charming. Did I give training tips? More like that, yeah. And honestly, we actually met much, much earlier. Not consciously, but rather unconsciously, because I think only the real die-hards know this. Sebastian and I come from the same area. Sebastian lives in Flensburg, I grew up in Husum, and there was always this club, the Domino, and you'd see each other there on Thursdays. So somehow we'd seen each other before. I was cycling back then, Sebastian wasn't riding yet, I think. And funny enough, Jan was the very first athlete I ever coached. He was still really young back then. And Jan Oellerich then rode for Stölting. That was THE development team. Riders like Politt, Schachmann, Silvio Herklotz came out of there. Those were real rockets. And yeah, I was involved with various teams and was a partner in some. And what really consumed me toward the end was the metabolic profile. Honestly, I have to say I did the calculations in my spare time. And I developed it, and Sebastian and I always talked about how you could combine things. And from that came — as you said — last year I was out of my old company, and Sebastian said, this is great, we need to program this. I said, I can't. And he said, no, you do it like this with Python. So I tried to piece something together in a fragmentary way. And Sebastian of course made the whole thing a hundred times better. But since then we have a system that allows you to simply upload data and it gets analyzed automatically, which is amazing because it's just incredibly fast. And above all, the costs are significantly lower than if you had to evaluate it manually. That option still exists, of course. If something didn't quite work during a test. But it should have high usability for the athlete, and then of course it should show you: I know the athlete's adjustment points, and that's what's exciting. And now we're combining that with an aerodynamic profile, and then it gets really fun. And that it's not just fun for us, but also for many other athletes — we just wanted to talk about that a bit. As I said, not that many people know us in Germany, or only the really dedicated ones. Abroad, the world looks completely different. Like the Endurance Innovation Podcast with Michael Liberzon. In the US and Canada, people know us much better. Or Michael Erickson with his Scientific Triathlon — we've been guests there two, three, four times. We're significantly better known there. And when it comes to coaches, even World Tour people use this system much more extensively and for much longer. And ultimately we thought, okay, it's really time we explain a bit in Germany who we actually are. And yeah, Sebastian, you have a better handle on the names — also the ones we're allowed to mention. Can you quickly say who they are?

Sebastian: So what I find incredibly exciting about the whole story is the Powertest. That might still sound a bit abstract, but fundamentally — I mean, I know it now, but we're trying to present this in a playful way. It essentially replaces spirometry, which we don't necessarily have to do in a lab — that of course still provides additional information, no question. But we can take the spiro to the road. We don't need a lactate step test anymore and we have a complete metabolic profile. And this is something everyone should understand — we all talk about aerobic and anaerobic capacities, about aerobic and anaerobic metabolism all the time. Then we should all agree that there are two metabolic systems. And the question is: how can a single value describe two metabolic systems? When I say one value, I'm talking about threshold. And then there's the system with VO2max and VLamax, which describes both of those. That's where Björn put his brainpower in, and that's our Powertest. And it's really in demand. And it's being used especially — and this is crazy — really heavily in Spain. We have great people we get to work with there. For example Javier Sola, who's a professor and essentially has a huge clientele of bike fitters that he trains, with regular conferences to develop them further. He's a really sought-after guy in Spain, also the one who's done by far the most Powertests — really, really many. But we also have Jehu Corral, who's a cycling coach at Team UAE Emirates, who uses the Powertest and the Aerotest. From Australia we have Calvin Poulton, who uses our metabolic profile — both the Powertest and the Aerotest. And Kevin's rider — what did he just place? Third at the World Championships. Third at the Worlds, yeah. That's quite a benchmark. There's also Denis Chevreau, a really strong Frenchman who just won Ironman Austria. At the same time, Katharina Grohmann came second — a fantastic German athlete who, alongside her job, working 30 hours a week, can still finish second in the professional women's field. And we also have Laura Zimmermann, who just won Ironman Hamburg and is both an aero tester and power tester. So that's the whole clientele around Utz Brenner. So there's another German who knows our capabilities and works a lot with us. And I mentioned Anja Berenek already. And someone I also find absolutely great is Pierre-Yves Vancompernol. He's not a pro, although honestly he almost has pro-level numbers. He's the head developer at Look Cycle. And he does fantastic aerodynamic work. He's done so many aero tests that hardly anyone can catch up. And what I always find great is that he's tested with every system out there and remains a loyal Afasteryou tester, because he's recognized the advantages of our system. One advantage worth mentioning — when you test aerodynamics outdoors, also with real-time measurement devices, the thing is that real-time data includes altitude data among other things. And when you're out there with such a real-time measurement device testing 10 or 20 times, riding back and forth, testing different things against each other, there's unfortunately a measurement error in such a device. And every run has a different altitude profile. With our server-based solution, we have the ability to process all altitude data, to fit it. to remove measurement errors and then use the same altitude profile for every single test. That's a real advantage we have over Chung methods and other approaches where none of that exists. So that's really great. And yeah, those are a few names. We also have Alan Hofter, who won the Norseman and is an aero tester. We have Franz Löschke, also an aero tester, who finished third at Ironman Frankfurt last year after our aero test and also won a 70.3 right away. And we have Jens Petersen-Bach. who coaches the fast Danish guys right now, who aero-tested with us. So the list is really long — pros and especially coaches who compete and train at the international level. We have World Tour riders that they coach, and we keep growing. We have more and more ideas about what we can build into the platform and where the platform will go. It's an exciting time. And those were just a few names I mentioned. Now here come the real rockets, because Björn of course also has a few guys who — just recently, King of the Lake — tell us, who did you coach there, what place did he get? Second place, little Pepplinger.

Björn: Exactly, we did an aero test a few days before and fine-tuned him a bit. And our calculation was off by about seven seconds on the ride time. Calculated on the platform. I thought that was really awesome. It shows how accurate it is. I'm more known in the mountain bike world. Mountain bike marathon especially. Markus Kaufmann, Andreas Seewald — currently European champion — Martin Frey. The list is a bit longer. I work a lot with Team Rinkhoff, because it's actually a nice playground, I'd say. In a Continental team you can still really experiment. There's Rainer Kepplinger, who came second at King of the Lake. But there's also Jonas Rapp, who just won the Friuli tour — the stage race that I think Pogačar won three or four years earlier. Then someone who finished second at the German hill climb nationals, Timon Loderer, a great strong rider. A Gudrun Stock, the German champion on the hill and incredibly successful on the track, unfortunately couldn't make it to the Olympics. But yeah, just to give you a sense of what we do here. I hope it's not too boring that we're naming so many people, but just to give you an impression.

Sebastian: I think sometimes it's pretty interesting to just know who actually uses the software and how they're progressing. And what I'd also find interesting at this point is that we have this Powertest on our platform that works fully automatically — unlike other systems — where you just upload your data and get your values right away. Everything is fully automated. And what I'd find interesting is — how long have you actually been using this metabolic profile for your athletes? How long have you been working with it?

Björn: Basically, I learned about it through an old colleague who did a really good job in that area. I had no clue about the calculations, honestly. But I knew which lever I needed to pull to make things work. And I think that's actually the real art of it. Because having some VLamax value and some VO2max value and influencing one in a certain way — that's actually the much bigger and much more exciting lever to pull, because... Knowing how something is composed is one thing, but knowing how I influence something to make progress — that's the much more exciting question. And we're definitely interested in that too, and it's coming, that we... show a kind of stress score — how was something influenced — so people have even more guidance. We already show that in our Powertest, but we'll go into more detail on that at some point. So people know, okay, I have a low VLamax, what should I actually focus on more. But we'll do that in a separate episode. I'll also add — maybe it'll be recorded, that would be great — I've been invited by the Olympic Committee in Israel to give a fairly big lecture. And if it's recorded, we'll definitely put it online and then we'll really get into the nitty-gritty.

Sebastian: You've really been working with the Powertest for a long time.

Björn: Yeah, yeah. I think nice examples are... I always calculate the throughput, energy throughput that you should ideally have with the oxygen uptake, to understand how this athlete develops. My goal is always to build stable athletes. That takes time. When I talk about training, I'm not talking about one or two years. It's usually with the long-term athletes. Andi Seewald has been with me for seven years. Or a Piramides. Or a Markus Kaufmann, forever already. And you can see that incremental development, and I love seeing it with Andi Seewald now — he's at the absolute world top. In mountain bike marathon, he's maybe unbeatable right now. This season he's won everything in record times. And that's simply been years of work where we calculated energy throughput every year, fresh each time. And there were years where I said, okay, listen, we're not doing anything other than raising VO2max. We did that in annual cycles. And then there were times when we said, okay, now we'll focus more on VO2max and so on. And now we're where we are.

Sebastian: Maybe at this point you can briefly explain again — because I don't think everyone knows — I did mention aerobic capacity and anaerobic capacity, aerobic metabolism, anaerobic metabolism. But can you quickly say what VO2max stands for and what VLamax stands for? So our listeners who are enjoying this for the first time get a quick overview, since we're already using these terms so routinely.

Björn: Okay, I'll keep it really simple, because we'll do another episode on this where we go more into detail. Very simply: VO2max is the horsepower, the engine. How much power do you have? VLamax is simply how many liters of fuel this engine burns when you floor it. And the dream scenario is obviously a huge engine, 16 cylinders, whatever — Ford Mustang, you name it. Floor it, gone in 20. And a Lupo engine. Three liters, that kind of thing. That combination you almost never see, but those are usually the people who win a Grand Tour. The problem is — it's a bit like Yin and Yang. You can't just say, ha, I'll push VO2max way up and then slam VLamax down. It's like when you chip away at one, it shifts a bit into the other. So I push VLamax up, then VLamax — meaning my economy, my fuel consumption — will most likely increase. If I lower VLamax, if I want to become more economical in my fuel consumption, especially carbohydrates — because that's the limiting factor at some point when you have a really big engine. We can't eat more than we burn under load. Then my oxygen uptake drops. And the question is always: how hard do I turn, and especially how long do I turn one lever before the system tips. And the great thing — this is what I always love about the Powertest — we can see in relatively short test cycles how things are moving. Just recently I had an athlete coming out of a heavy training block. with incredibly high energy throughput, and we did two Powertests back to back just to quickly check recovery. And I just knew, okay, VLamax is in the basement right now, VO2max has also dropped a bit — he's simply not recovered yet. You can look at other parameters too, like HRV and all that — it was all visible. But it was a little test run. And then you could see, okay, now he's recovered. Everything went back up a bit. VO2max is up again. VLamax also went up a little. And you can test in relatively short intervals whether what I'm planning as a coach is actually working. Because often — and I see this all the time — the plan is to achieve X with Y training. But honestly, no coach in the world — I wouldn't even put my hand in the fire that, I don't know, 25 hours of base training with only Fatmax or Fatmax intervals for a highly trained athlete will definitely have a positive effect on VLamax or VO2max. That's sometimes not that predictable, because who knows what the athlete is eating. You can't track that — or we can't track it. I don't know how much they ate. Maybe it totally backfired. And that's why a Powertest is the insurance policy for the athlete and the coach that we're on the right track. And I can intervene quickly and say, hold on, something's going wrong here, we need to work differently. That's what I use it for.

Sebastian: Yeah, you can tell pretty quickly that you're immediately deep into it. I literally only asked you what these two building blocks basically are, and you can see right away — you're immediately thinking about how to also show how to train these two aspects, that they're interdependent, that it's not simple. It might be Plan A or Plan B, and over the years you've learned that sometimes you have to take completely different approaches. But what personally convinced me — and that's why I thought it was so great — is exactly what you just said. And of course it's always a bit redundant to repeat things from someone else, but it's just awesome that you can verify things. And at regular intervals. And personally — triathletes know this well — you train for a whole year toward one big event, and if you don't do any tests in between, you're basically in free fall. And then using competitions — like Olympic distance, shorter distances, earlier on — to compare yourself or use PBs doesn't necessarily tell you anything about how the long-distance race will go. And since I'm a natural scientist and ultimately an engineer, I always believe that if you truly want to improve something, you need to control it. And controlling means measuring. Doing a target-actual comparison and then being able to react accordingly. And I always wonder — sure, I can do aerodynamics without testing, just based on best knowledge and judgment. That'll also work if I was pretty bad before — I'll still be more aerodynamic. But at a certain point, I can only improve through targeted testing, because that's the only way to find out what works and what doesn't. And ultimately it's the same with the Powertest.

Björn: I also think — and this is the key point — you have to sensitize athletes to things. Both for Powertests — like when I say, okay, we're riding 480 watts now because that's a VO2max effort. Sure, we know it takes a moment to kick in and all that, but that's already the first step. Or simply telling people: look, you should eat something during training, because the Powertest also always shows how many grams of carbohydrates you're consuming. Sure, there's some fluctuation. But as a first step — eat something. Yeah, because in many heads it's still: best to eat nothing at all. So sensitizing athletes to training — and they realize pretty quickly, look, when I ride at this throughput, it really works. Then I can still ride the next day and not completely blow myself up on one day so that the next day nothing works at all. And that sensitization. And the next thing — and this is what I find fascinating about the aero test — here too, you sensitize yourself to a position. And not just on the time trial bike, but also on the road bike. We've seen that World Tour teams don't just test on the time trial bike — they also test their regular bikes. And then you sometimes notice, wait, they're not riding disc brakes. Why? Well, it might have something to do with that. Or what position do I ride on my road bike? Ideally, when I'm at the front. How do I hold my hands? New UCI regulation. What should I do? What handlebar width do I ride? And so on. And the great thing about aero testing is I can constantly verify it. I know every time — okay, bottle here, bottle there. Hey, does riding with a saddle bag maybe make me faster? All these little details, and at the end of the day, that one percent more or one percent saved in power might be the one percent that brings you the win. And we know, in the World Tour or in the Continental or Pro Continental level — hey. Sure, you've got 5.8 watts per kilo at threshold or 6 watts. What good is that if you have a tire that doesn't roll? Or if you're an aerodynamic wardrobe?

Sebastian: Yeah, and ultimately the challenge for athletes who are just starting out is that the portfolio of things you can do is absolutely massive. You need to sit aerodynamically, you need to train perfectly, you should eat no carbs, you need to foam roll in the morning, do core stability, you need to do yoga on Wednesdays, and if you take the right supplements you'll be particularly fast, and if you do this training you'll be really good. And of course the challenge is to filter out what are actually the important aspects — especially, as you always like to say, the low-hanging fruit. And those exist in many ways — in training too. That's why it's so important to have good coaches if you want to reach a certain level of professionalism, so you can learn a lot. That's how I always see it — you can learn an incredible amount. And what we're also seeing — which that list of names has really shown — is that more and more coaches are simply not leaving it to chance. There are so many coaches now who use metabolic testing and implement it so they can train their athletes better, and who simply don't leave the aerodynamic aspect to chance anymore. And at the latest when they notice that their athletes — with whatever watts they're putting out — are doing an Olympic distance time trial and some other guys putting out maybe only 250 watts are just as fast, you have to wonder at that point: something doesn't add up. And those are exactly the people who come to aero testing. The differences are so huge and there's so much potential. But it goes beyond that too. Sometimes you have to train for a whole year to get what you can gain in a single day of aero testing. Yeah. And that's why we have a really awesome combination of capabilities on the platform. We've already found so many clients who can bring real added value to their athletic environment with this software. Absolutely. What I'd also like to do — let's go back to the Powertest for a moment. A lot of things get calculated there. Obviously what you said, but one important aspect you just mentioned that I'd like to pick up on — you train VO2max all this time, but you can also wreck yourself doing it. Plenty of people say that. But you've already found data points in the Powertest that users can actually use. It's a frequently asked question, and it's actually included in our reports — training zones. Can you talk about how doing a Powertest gives you real guidance for how to structure your training volume?

Björn: Exactly, so we calculate based on energy throughput — it's actually oxygen throughput if we're being honest — but we can only properly measure energy expenditure through the power meter. How much energy throughput I can maximally do per day while still getting a positive adaptation rather than a negative one. I see it with tons of pros — they're incredibly dedicated, but they always do a little too much. Always about one percent. And they don't get better, they tend to get one percent worse. So we provide the guideline: how much energy throughput should I ideally be doing per week for something positive to happen? What's the minimum, what's the maximum? Obviously for someone who trains very little, the minimum is very low. That's called utilization — even very low utilization works. But you pretty quickly see when it's too much. And I think the nice thing is you can also see — when I go to a training camp and blast through 25,000 kilojoules, which would be really high energy throughput.

Sebastian: Can you say what that would be in hours? 25,000 kilojoules? Does that mean 20, 30 hours on the bike?

Björn: Yeah, somewhere around 30, depending on where the base zone is. Something between 25 and 30. So really a lot. And trying to eat all that — roughly times four — 25,000 calories is of course... well, assuming about 23 to 25 percent efficiency on the bike. So then the next question is: how much should I be training in the other zones? Is VO2max training with someone who has very high lactate production the same as with someone who has very low lactate production? It's not. Someone with very high lactate production can stay in those high zones significantly longer, at least in terms of watts. You can see that too. Sometimes in a spiro — they take a bit longer to reach VO2max at the top. Whereas someone with a low VLamax — and you can see this in how threshold power and VO2max power are very close together — already gets a significant VO2max stimulus from 90% VO2max or slightly supra-threshold training. Or you can prime it by going in hard first. And then coming down to threshold or just above, and you get a good VO2max stimulus. These are all things we'll get into more detail on in the future. But based on their metabolic profile, we already give people a guideline — this is enough, this is too much. And when you train across different regimes — base, VO2max, threshold training, everything included — you should ideally ride at this target power or maximally at this target power. And that works, maybe a topic for another time — we could invite a nice guest — ideally in a form of block training. Where you say, we're working very specifically on one mechanism we want to influence. And then we do maybe six weeks of VO2max work, or three weeks, depending. And yeah, you can read that pretty well from the data. You've got a good guideline. And it's not a shotgun approach of doing everything at once. That also works to a certain extent. I always tell someone who isn't fit... they'll get fitter from anything, and it really doesn't matter that much what you do. As long as you do something, and enough, and eat enough — that'll definitely lead to a positive adaptation eventually. But when we're in the high-performance range, and there are quite a few of those on our platform, then you have to train smart. Not too much, not too little. The stimulus has to be targeted.

Sebastian: What I'm taking away from this, and what I find really fascinating, is — when you're out there as a layperson, an amateur, and you hear about training VO2max — if you ride at VO2max or go full gas in the VO2max zone — and you just described this — someone with a high VLamax, who can produce a lot of energy through carbohydrates, they can ride longer, shorter, more intensely. And maybe get higher stimulus. And someone whose VLamax is a bit lower doesn't need to ride as intensely at all. And maybe you can briefly say something about how intense I actually need to go... Obviously if we do a Powertest, you get the exact zones presented to you. What would you say — what does the average person out there do? Do they ride too intensely?

Björn: The average person feels like they're riding too intensely. The question is always: what is intense? Is it your own perception, or is it really what the power meter shows? Like if I ride three hours at GA2 sweet spot tempo — when I get home, which I don't do and couldn't even do — preferably without eating — then I arrive home and I'm dead. I'm wrecked. I feel like a galley slave. That was intense. Perceived. But was that the right stimulus? No. Intense — if we talk polarized training, which is on everyone's lips — means I hit the target zone in terms of watts that I want. I can still beautifully cross-check that with heart rate. Then I see, okay, if heart rate goes through the roof and I'm riding those watts, I've definitely already got a good VLamax stimulus going. Someone with a high VLamax — just as an example for those who know their stuff — let's say 0.7 lactate production, good VO2max — four times eight minutes at 30/30 isn't going to faze them. Even 40/20 is still doable, it hurts, but it's fine. If I had someone with a low VLamax ride that, they'd be completely wrecked and it would most likely be way too much.

Sebastian: Yeah, I'm also thinking about those people who don't know this great Powertest and don't know their VLamax, and then they get their training plan and ride VO2max intervals at power based on FTP. What happens for someone with a very low VLamax? If I tell them, for example, I'm just going to calculate their VO2max intervals from FTP.

Björn: That's exactly the problem. You put it really well. FTP as a melting pot of different systems — put simply — for someone with a low VLamax, VO2max power is much closer to FTP. And then they'd most likely completely blow themselves up. For someone with a brutally high VLamax, a real sprinter type — who knows how many percent, 120% of FTP — that probably wouldn't even scratch them. And we wouldn't get the stimulus we actually want. So you can train much more specifically rather than working from one single value. Which is ultimately just this melting pot of different systems.

Sebastian: And I think that's a really interesting point. Because I bet there are people out there who experience exactly that — who really break down from that FTP-based VO2max training because they have such a low VLamax. And then the other person wondering: nothing's happening here at all. When does the intensity actually start? And the Powertest reflects that really well.

Björn: There's always — I don't know — you buy some pre-built training plan, which is a nice thing because it's totally user-friendly for the athlete. Then you get intervals and whatnot, and it says something like, FTP something-or-other will make you faster. That works brutally well for some people, for others it doesn't work at all. It's just not individualized.

Sebastian: So it only actually works if your VLamax is in a certain corridor. If you're the classic average athlete, then FTP has its justification. But if you drift higher or lower, then it gets uncomfortable for you.

Björn: And ideally you also have a coach who adjusts things on the side. Maybe you notice during training, okay, somehow they're getting fitter. Maybe I need to tweak the intervals a bit. Or I notice, oh, that's a bit much. Let me dial it back. So ideally you have someone who intervenes. Which is also something for the future — we've been spinning ideas for a while — where you'd say, okay, red light, too much, let's take some out, otherwise we won't get the adaptation we want. You can of course cross-reference that with biometric data — heart rate, HRV, whatever — to simply track these trends.

Sebastian: And what I also find really exciting about the Powertest data is that it's not just these zones — how much time should I spend in these zones to get an adaptation in that value. VO2max is relatively simple to imagine — it has an effect on VO2max. But then you can ask other questions too. What do other training zones mean? Where do they have an effect? We can definitely talk about that more. What I really appreciated is that you're not just talking about training times and intensities, but also about a really important factor that's unfortunately often misunderstood. You've experienced this firsthand and clearly say: what about energy intake?

Björn: That's the biggest crux. I see it, and it's always fascinating and also difficult for some coaches. What does it actually mean for the athlete when they're in threshold training — how much energy are they burning? Roughly speaking. We don't always have a steady state. It fluctuates a bit here and there. Depends on the weather, whether they really ate enough, and so on. There are also those fun sensors you can stick on your arm — maybe we can do something with those too. Fundamentally: if I don't provide the energy I need at this power output, then the body will find ways to work around it or adapt. And then the adaptation might be a completely different one. What happens when I do higher-intensity intervals — sweet spot, threshold and so on — with too little energy intake over a longer period? Then most likely my lactate production will drop. Or — and this is the classic scenario I see — if that's intentional, fine, over a period of maybe four, five, six weeks, well-controlled. But if it's done long-term, let's say four, five months, then that athlete will train themselves into overtraining. Simple as that. And I observe that quite often. I get training data from athletes, I look at it, and I look at the training plan they followed. Sometimes — actually often — there's no nutrition guidance at all, or it's insufficient. Or the coach didn't even address the fact that the athlete — we're not training robots, we're training humans — that the athlete rode fast. They say: I had a great feeling, I was fast.

Sebastian: That's the emotional component of the athlete, who then maybe also...

Björn: Yeah, obviously. And the athlete gives in to it. It says so on the screen with nice colors and it's all written out and then everything always looks very correct because it already has a good format. But when it says something like three hours of sweet spot with 30 grams of carbs per hour, and the guy has, I don't know, an 80 VO2max, he'll most likely wreck himself.

Sebastian: That's also really interesting, I think. What you can generally see is — and as a coach you certainly have more information — that athletes often want to do things even better. And doing it even better means, for example... There's a VO2max zone — I'll do it even better — I'll just add another 20 watts on top. Or I'm supposed to eat 30 grams per hour — hey, I'll do it even better. And unfortunately, from what I understand, that's really a problem, because training stimuli are calculated very precisely. And when an athlete thinks they need to do better than prescribed, that's unfortunately not how it works. You're selecting a very specific range where you want a very specific adaptation from the athlete. And that certainly requires some education when working with your athlete.

Björn: Yeah, a lot of education. And that's a really interesting point you're making, because there are athletes who — if it doesn't hurt and they're not drenched in sweat in the corner, it wasn't training. It wasn't good. Threshold intervals are a great example. I once had an athlete who was supposed to ride twelve times five minutes at 350 watts. He rode 450 watts. He barely managed it. I saw the session — oh my God. Dude, that was way too much. Well, I didn't say 'dude.' I said, that was clearly too much, we need to reduce, and so on. Let's skip the next session, let's just see. And what does he do the next day? Gets on the bike, wants to do intervals again, suddenly realizes nothing's working anymore. The whole training was crap, he says. No — you just rode 100 watts too much. You have to disabuse people of the notion that every training session has to feel hard. That's nonsense. And what's much more exciting — and this is about consistency — training means having constancy over very long periods, over years. Building on top of each other. Having minimal training downtime. Because then we'll keep getting better and better long-term. You can see that with many pros too. They've simply been able to slowly raise their level over years. They have very few interruptions, very few illnesses. They take two weeks off per year and then slowly start again.

Sebastian: And that's exactly where the Powertest helps, because it provides volume guidelines, intensity guidelines based on your actual current metabolic performance, and it also provides reference values for energy intake depending on what you want to do. And now — you already mentioned that you'd dynamically decide with your athletes whether you need a Powertest. But assume we know your athletes, you've had them for a long time. How many Powertests would you do per year to be able to steer and adjust?

Björn: Typically I do about four to five Powertests per year. And sometimes just quickly — let's say end of season, I want to throw in a quick lactate shuttle for the guys. Where exactly do we need to target? Quick test. The nice thing is, they already know the test protocols, they have their routes and everything. We just know, okay, boom, here are the results. Okay, we'll ride in these zones for a bit and then we can quickly reach the adaptation again. Just briefly worked on one system, boom, already achieved it. It's like diagnostics. It's simply diagnostics that we can access permanently. And if I always use the same power meter — ideally — and calibrate it beforehand, I have reasonably valid data. That's the beauty of it. Sure, a power meter can read too high.

Sebastian: That could be its own topic.

Björn: We know ourselves — we recently talked about some funny spiro data that was sent in. There too, a lot can go wrong. And you really need good people running the spiro who can also interpret the results. If you put an untrained person there who's done it five, six, seven, eight times and the ergometer crashes because it's not properly regulating, or the nozzle is clogged on the spiro, then we're measuring garbage. I'm...

Sebastian: a really big fan of field tests. And the reason I'm a fan of field tests is because I've had my experiences with my aerodynamics background. Because back then... I've been doing triathlon since 2002, and in 2007 I did my first long-distance race. I worked in the wind energy industry as a development engineer, designing and developing wind turbines. I learned a lot there — about wind, and especially about algorithms. That's also something I'm passionate about. I just like algorithms. Otherwise I have no problems, but those I like. That means you have no friends. Algorithms and — no, no, all good. But I've always had a soft spot for that. Anyway, what happened was that in the triathlon world back then it was already interesting to me. I wanted to know for my long-distance races — when everyone was writing about what's important — what are 10 watts actually worth? How much faster am I with 10 watts? And if I put on a different wheelset or have different rolling resistance, how much faster am I? Is it worth it? I wanted to have some actual facts in hand to ultimately make much better decisions. Not just gut feeling because someone says, hey, this is amazing, now we all do it. I've always been too analytical for that. And my challenge, living in Flensburg, is that we have a ton of wind here. Which also makes it obvious that wind makes a huge difference. That's actually why I ended up in the wind energy industry — because we have so much wind here and I was a bit of an eco-person, and maybe still am. But I wanted to test and there's no wind tunnel around here. So it was the velodrome. And so the first time it was the velodrome in Büttgen. And if I have to schlep to Büttgen to test aerodynamics — knowing that a test day can easily come to nothing because it depends on many parameters, like the power meter has to be accurate, the speed sensor data has to be there. With our system now, everything is fully automated. But it wasn't back then. When I first went to the velodrome — I think it was 2012 or 2011, I'm not even sure — at Büttgen. And everything wasn't fully automated yet. And you have to say at this point: things can go wrong quickly during an aero test. And when they do, I have to drive there again. And that was basically my idea back then — well, not really my idea. I just asked myself: how can you test aerodynamics at home? And that's how I ultimately tried to develop an algorithm that makes exactly that possible. And that's also what many pros and World Tour teams use today to test their aerodynamics outdoors in the field. Because from an aerodynamic standpoint, everything has its pros and cons — every measurement system has its pros and cons. They all have their justification and each has different aspects that can be tested particularly well. But it's fundamentally important to simply have that field test available on location. And that's the same with the Powertest — having the field test on location, not having that dependency where on Wednesday, like a sword of Damocles, the Powertest is coming and you have to perform. I know that athletes get stressed by that. And when the day is set in stone and everything has to be perfect, then the week before can also get really awful because you just don't feel like it at all. Being measured like that and really seeing what's inside you — everything has to be right. It puts people under pressure. And with the Powertest, you have the option to say, hey, today's not working, let's do it tomorrow. You don't have any dependency. The other advantages I sometimes see from a measurement perspective — of course lab diagnostics has its justification and you get other parameters that you can't get in the field. But when I test outdoors or do my training, I do it with my own equipment. And if I don't do a lab test with my own power meter, I have to ask: how is the error between the two systems corrected? It isn't, right? And those are the crutches that you lose on the other side despite the better measurement equipment, because you can't transfer the reproducibility to the road, to training. And that's why you can say, okay, what are the pros and cons? And there's certainly — and you're the expert on this — justification for going to the lab sometimes too.

Björn: Lab values are important. I have an expensive EKF here myself, which I use to take lactate values, to test: okay, what are we actually measuring in reality and what are we calculating? How close is it to reality? Which is always important when we're developing new things.

Sebastian: But I'm wondering — to jump in real quick — when I think about who our testers are: sure, it's the World Tour teams and the absolute crème de la crème, just like you, testing at a very, very high level. But for the ambitious athlete out there, the system is already sufficient as is. They don't need anything more. They already have everything they need with this. And the coach has everything they need too. And sure, if you say, hey, I'm training now and I want to become world champion, then you might need to say, okay, we need a bit more sensor background and even more precise values. Or if you're like you and me — we're ultimately software developers, and we really try to be at the cutting edge. We put a lot of time, work, and brainpower in, exploring new algorithms. We're working on our first ML implementation — machine learning. So there'll be completely new things coming from us in the future. And we're doing this to make high-end diagnostics accessible to everyone. Yeah, that's the future too.

Björn: I mean, we experienced a big impact with COVID when labs were rightfully closed. You're obviously not going to do a spiro during a pandemic. That was a real alternative — suddenly people could test. And I'm still a big fan of spirometry when it's done well, when the system is properly maintained, and when there are people there who know the software and the equipment. And ideally they also understand something about the sport. How does the athlete sit on the bike? That all has an influence. And sometimes something's off with the bike — I've seen everything. Or there are different chainrings on, so the power meter now reads differently. When we calibrate — let's take a cycle ergometer that regulates and you can put your own bike on it. Then you can see — and that's exactly what you mentioned — we can compare how accurate my power meter is versus the cycle ergometer, both calibrated beforehand. You can sometimes see deviations. Okay, maybe I need to do that differently. It's quite nice. But you really need people who understand these systems, and that's critically important. And if you can do it yourself — even if there's an error in there — you'll at least get good data from our system that you can train very well with. And that's enough for a lot of people. For people who finish third at the World Championships. Or European champion in mountain biking.

Sebastian: So 99 percent, I'd say. Obviously, that makes the whole thing incredibly sexy.

Björn: What we shouldn't forget — and I always find this fascinating — just because something is done in the field doesn't make it worse. And just because we put someone in a lab with a spiro doesn't make it better. Think about it: we have a phone, it's a high-tech computer. These devices are incredible. With a power meter recording data, we have massive amounts of data. We have a wealth of possibilities we haven't even begun to tap into. That's guaranteed. And we're already playing around with a lot of this. We can still interpret and calculate things. Heart rate and heart rate behavior. Now we're measuring glucose. We can measure body temperature while riding. What else can we extract from that? It's insane. And that's much more exciting — doing a test and then pulling all that data into a platform long-term to see what's actually happening. What are the trends? What does it all mean? Instead of always just having a point-in-time snapshot on day X, as you said — in a climate-controlled room, maybe on my own bike, maybe not even on my own bike. And everything has to be perfect that day. I was always terrible at lab tests. I always had awful LDs. And at the end of the day, I still rode well.

Sebastian: Yeah, not everyone might know this — you were actually quite athletic on the bike yourself.

Björn: Yeah. Not as good as the guys we test, but pretty okay.

Sebastian: So that's also your passion. Cycling was it too.

Björn: Of course. And it was especially exciting when I had Jan as an athlete. Jan was very young, 15 years old. And when you bring someone to a very high level, have them ride for a team where later the elite are — Tour de France stage winners — that's obviously awesome. That's really fun. And the experience I started building from the mid-90s, when the first power meters came out — PowerTap wired with a cable and all that. There was also Ergomo. SRM of course, but absolutely unaffordable — no one could afford it. PowerTap hub, yeah. I bought a PowerTap hub in London back when I lived there sometimes and my friends were studying there. I think I bought a wired PowerTap hub on eBay in London for — I don't know — 400 pounds. It was great. When was that? What year? Must have been 2002 or so. So a long time ago too. Yeah, a really long time ago. And I know the first guys had SRM. I mean, Telekom was riding around with those. That was just mind-blowing stuff. And we had absolutely no idea what you could do with it. You had this number and you didn't really know what it meant. And then came things like aero testing. Brilliant. I mean, it's a power meter. You can do so much with it. How much you can derive from it.

Sebastian: When you think about it — with our platform, de facto you can do an aerodynamic test if you have a power meter, and you can do a metabolic test if you have a power meter. So the power meter has really evolved into an incredibly important measurement tool that offers so many possibilities. And the best part is... And that's one of the reasons you can say: maybe don't go with the cheapest option, maybe invest a bit more in this precision instrument. Because you simply have all the options for the future. You can do high-end metabolic tests and you can do high-end aero tests — all with a power meter. And that kind of makes it the most important measurement device on the bike.

Björn: Yeah, many people don't even realize that. At least when I talk to them. Power training is super important and all that. But there's also this thing of — what can we actually extract from it? How much? People aren't even aware that with a power meter we can do amazing aero tests and create metabolic profiles. And then... I'm also a huge fan of heart rate, because it's that direct feedback tool. What is your body doing right now? And it's also incredibly well researched. And then seeing everything in relation. And that's what we do — we simulate. Unfortunately some programs or the analysis programs we have don't offer that. So we're currently building our own tools, and sometimes really surprising things come out — like how heart rate, cadence and so on behave when people fatigue. And those are exciting things. How can I work around that? And when we have data — and this is the fascinating part — data from world-class athletes who all raced the same race. Where is one better than the other? Do we already have indicators for why one gets dropped and the other doesn't? And we already have the Powertests. Is there something there? Did one ride smarter? Did the other waste too much energy somewhere? When we overlay data and run our various algorithms over it, we suddenly see: hey, why was this one faster? Wait — he was on a different chainring. Let's say oval, just to throw something out there. These are the fascinating things.

Sebastian: When you say 'tinkering,' that's a bit of an understatement. We invest quite a lot of time into developing proper statistics, finding the right algorithms, building models that we create ourselves, testing them against hard statistics, and iterating. And in the future we'll certainly use more machine learning to also find — from a computational perspective or from the models — machine learning models that can perhaps describe reality even better. And what's special is that we've received such a massive flood of Powertest data. We have over 20,000 aerodynamic tests on the platform. And honestly, that gives you significantly more possibilities to develop things further. When we develop new aerodynamics algorithms or try to improve our overall algorithm, we can always run it against the current one and see how the improvement plays out, and whether it makes sense to put a new algorithm live. And that's obviously an advantage of data. Which you don't have if your system doesn't collect data. You can always discuss pros and cons, and data privacy and the problems that come with it. But for developing technical solutions, algorithms and models that describe human performance, data is incredibly important. And our goal is of course to bring this know-how back to people in an affordable way. And we don't sell any data, nothing at all. And we don't have advertising on our platform either. We're really clean about that and try to let people focus on what actually matters. And I'm super happy that we found this path. Björn, man, that was quite a rollercoaster, that's how I felt. We just blasted through everything.

Björn: Paraded every pillar through the village that we have. And we could honestly keep talking for several more hours.

Sebastian: Exactly. I think at a certain point, we've used a lot of buzzwords and thrown them around and talked about how great everything is. I think it might have given one or two of you a preview of what's on our platform, who we are, and what we're developing. In future podcasts, we can certainly — and that's our ambition — present certain topics in more detail. Explain how to do proper aero testing, how to improve, what to watch out for with measurement accuracy. And the same for the Powertest. What's important in a Powertest? How do I interpret the results? How can I use it to design my own training? How do I properly integrate it? We really have a broad portfolio that we can offer users out there as genuine added value. And then always the ongoing development of our software solution.

Björn: Yeah, so everyone is of course warmly invited — everyone's invited to write to us about what interests them. We asked on Instagram a few weeks ago what you're interested in. Some really funny suggestions came in. We'll do those in the pre-Christmas special, which questions were asked. But always feel free to send them in. We'll invite people. You know — or some of our listeners know — who we work with, who we coach. We've given a bit of a preview now. Maybe there are also requests for us to invite specific people. That's the plan. But maybe there are also requests from listeners saying, hey, could you invite so-and-so? That would interest us. And we can definitely go deeper into that. Exactly.

Sebastian: Awesome, Björn. That was fun.

Björn: Good, yeah. Considering we hear and see each other every day anyway, we did pretty well. Cool. Let's wrap this up. You'll hear from us again and we appreciate it. Thanks everyone. Ciao.