Physiological Testing with Renee Eastman | KoopCast Episode 163

Trail and ultra runners, what is going on? What's happening? Welcome to another episode of the KoopCast. As always, I am your humble host, Coach Jason Koop. And this episode of the podcast is all about physiological testing. I know that many of you have seen on social media some clips of elite athletes straining on a treadmill with the whole mask set up. Or you might have even read some research that compared athletes lactate thresholds in VO2 maxes before and after an intervention. Testing for lactate threshold and VO2 max by way of a graded exercise test can be a useful window to drive training decisions. However, many times the testing and interpretation is not as simple and straightforward as what you see in a test.

It takes a keen eye and years of experience to ascertain how we take testing from the lab into the field to the benefit of athletes. Make no mistake that this process is a valuable one. So much so that there was once a time where every single one of our CTS coaches were trained on how to administer, interpret, and apply a graded exercise test using oxygen consumption and lactate sampling. Every single one of them was trained on this. We believe that it was not only valuable to each athlete, but it was a valuable part of the coaching process. So enter into the field Renee Eastman, who is the head of our physiology lab at CTS. Renee has been working with athletes since 1996 when she was a sports science consultant for USA Cycling in advance of the Atlanta Olympics. And since that point in time, she has held nearly every single position at CTS from being our head, one of our head mentors running our lab. And we even traded turns being each other's bosses at certain points during our career. Whenever I have an athlete come into our physiology lab, which I've had many of my elite athletes and everyday athletes alike come in, I can always trust Renee at the helm of those controls. In addition, Renee is an excellent athlete, which is something that she is far too humble to mention, but I certainly will. She's a six time Masters national champion on the road and track and cycling. But more importantly, she is the quintessential example of a great athlete who makes an even better coach. What I wanted to do during this

podcast is to demystify the whole physiological testing process. Regardless of if you can get into a local lab, come into our lab in Colorado Springs, or even if you don't have one available, I hope you glean some insight into how to take metabolic data and turn it into better training decisions. All right, with that out of the way, we're going to get right into it. Here's my conversation with coach Renee Eastman. Thanks for coming by the house. You're welcome. That's not like it's not far from a truck for you, but I always appreciate it. Oh yeah, it's easier this way. I always appreciate recording in person versus having to do it over the zoom or whatever. Yeah, I did one this morning with somebody who's in Spain and the lag is actually kind of tangible. Sure. But anyway, neither here nor there. So we're going to talk about testing. Yes. We're talking a little bit off air about this is the time of year for testing because everybody wants to recalibrate everything. New year, new you.

I want to set my zones up. I just got into, you know, like XYZ race and we're going to go through all of it. But I think to kind of set the stage a little bit, we probably have somewhat of a naive audience in terms of what physiological testing actually is. And in order to set that context properly, we kind of need to know like why people are coming into the lab in the first place. Like what's the value proposition that they're initially seeking? And then from that, we can go through the protocol and the whys and all those other things. So when people are coming in, Renee, like, like what do they want? I think most people are naive. Even the people who come in to test, they're naive to what the test can tell them. But the two things that most often our runners want.

Yeah. What's my VO2 max? What's my LT1? Hasn't changed in 20 years. Right. Cyclists a little bit more savvy. They're, you know, a little bit more FTP oriented and things like that. But those are the things that people want to know to help establish where their training ranges are. And specifically people, the most of the most recent people I'm getting, they all want to know where their aerobic training zone is. Put in CTS terms, their aerobic endurance zone two. Yeah. Well, zone two has been taken off. It's hot right now. It seems like every time you turn around, somebody's talking about zone two and it's for good reason. I mean, it's a cornerstone of endurance development. It's not the end all be all of everything, especially for an endurance athlete.

But I can definitely see like you happen to pick up a lot of that just because it is in the popular literature and across podcasts and Twitter and things like that pretty much weekly. Absolutely. And, you know, having gone through all the trends over the last 20 years, I've been working for CTS for 20 years. I've been in the industry for a little longer than that, where base training was in vogue back in the early aughts. And now it, you know, then we went to time crunch. Yeah. High intensity all the time. High intensity training. And now we're back to zone two training. And I think in particular for the ultra distance, both in cycling and running that kind of that wave of recent, I think that that is one reason that the aerobic base training is, is all in vogue.

And we'll probably go through another cycle by the time you and I are finished with our coaching careers. We'll see it. We'll see another cycle of high intensity for sure. So, so the athletes are coming in with some sort of preconceived notion, right? I want my VO two max. I want my zone two range or the top of my zone two range or LVT one, LT one, whatever you want to call it. Yeah. But as a practitioner who sees a ton of these tests, what should the athletes be coming to the table with? Like what should they want to actually get out of it? That's a great question. And I think the purpose of testing is to help an individual or coach make better training decisions. You know, the, what should, where's my strengths? Where's my limiters? What's my like limit of potential and kind of a follow-up, am I doing what I think I'm doing in training? I think that that latter part is probably one of the most important parts is because a lot of people think they're doing, let's say, aerobic base and getting better mitochondrial efficiency and in better ability to run on fat as a fuel source and all those kinds of things. And they may or may not be.

Yeah. Um, and the testing that we do can bring out that data. You know, number one, what we get is what's the limit of their performance. That's VO2 max, the upper limit of their, you know, VO2 max, uh, or aerobic, uh, capacity. Then the back in our olden days, all we were identifying is what we would call LT2 now, commonly referred to lactate threshold or in the cycling world, FTP, you know, they're all kind of about the same thing, that break point of splitting it between aerobic and anaerobic. Um, and over the last few years, what we've, you know, further identified is the aerobic threshold or LT1, that first inflection point of the threshold. Um, but back to the, what do we get upper limit of performance threshold? What is, what percent of that maximum capacity? Can I sustain? Um, the understanding if somebody is at 70%, their lactate threshold is 70% of their VO2 max, they have a huge capacity to lift that up.

If somebody comes in and their threshold is 92% of their maximum, then they're kind of limited more by their VO2 max. Yeah. Going back to the bet, make better training decisions. There's kind of, I've always viewed it as there's two construction points around that. The first one is, is just how you mentioned, what is the athlete coming to the table with initially? What physiological traits or genetic traits or combination of those two does is the athlete currently presenting as, and how can we more effectively design both long and short term training architecture to either accentuate their strengths or cover up their weaknesses, whatever the goal within the framework of the event actually is. That's the first part. And then the second part, we're going to get into kind of both of these at some point.

The second part is more of a chronic piece, meaning after we have done training, have we pushed and pulled on those physiological variables to the extent that we think we have. And a lot of times that, that, you know, it's very hard to actually tease that data out because of the sensitivity or lack thereof of, of the test, or maybe the athlete is already so good that we're not quite pushing on things as much as we, as much as we thought we did. But that's the way I've always divided it into initially we want to see the strengths and weaknesses, set up some sort of zone or range construction. And then long-term we see how the training is actually taking an effect. Exactly. Exactly. So before we get into too much of that, let's set up a test, like just as you were to describe it as you've done hundreds of times. So an athlete coming in the lab, they've never experienced a test before. What is an athlete going to experience when they go through some sort of physiological test and more specifically the ones that we do?

Right. So I'll describe a lactate threshold VO2 max test. Yeah. It's a graded exercise test. And that indicates that we start easy and get progressively harder. And the time durations that we use currently, I'm using four minute stages where they get on the running test. We started a relatively slow speed and increase 0.3 miles an hour or about 40 seconds on the, on the per minute on the mile faster. And we are measuring, and this is actually, I should back up for a second. In our running test, we actually, the LT and VO2 max tests are separated into two separate portions of one test. We do the lactate threshold portion first, and then we do the VO2 max. So I'm describing the lactate threshold portion that are the long three to four minute stages that get progressively harder. And what I'm measuring in that test is heart rate. I'm measuring oxygen consumption. So they have a mask on and we're measuring what they're breathing out because we're, we know what the oxygen content of the air is and we're measuring the carbon dioxide and oxygen content of what they're breathing out. So we understand what they're extracting.

The lactate part of the test is I'm actually measuring with a fingerprint blood sample. There are blood lactate values and I take it at the end of every stage. And on that first, you know, progressive part of the test, that's a long portion of the test. Ideally, it's taking 25, 30 minutes, sometimes a little bit more. I don't want the test to take 10 minutes because it's not long enough to establish a nice baseline. It's too aggressive. And I don't want the test to take 50 minutes because then fatigue begins an issue. So the, one of the key elements is picking the start speed of that. And we can go into that sometime, but picking it at a pace that is maybe in somebody's active recovery zone one or bottom of zone two, like a jog, if you will.

And how would you determine that? Just training data, race data, combination of the athletes feeling of where they should start warm up stuff. Like we've, we've kind of been through this before, but I think like the listeners would get a kick out of how we try to figure that out. I think that's probably one of the things I, the, the institutional knowledge that I've gotten over doing however many hundreds of tests on our athlete population. If I get a road runner, they know their paces. I'd be like, what's your 10k running pace? And they're like 45 minutes and 32 seconds. And then I can back up from there and pick great start speed because they are dialed in on their paces. That is not the case for most people. Especially ultra runners, you know, that nobody's paying attention to pace. Right. So I watch them in their warmup. I am observing what I give them a 10 minute warmup. It's, it's self-paced and I give them an instruction to like a light jog or light warmup that I don't want them doing like a pre-race warmup where they're doing like openers and cause I actually don't want them to spike their lactate too high. And, uh, during their warmup, I'll take a baseline lactate. And if their baseline lactate is high, which high would be like three, I'll be like, Ooh, that's too fast. Um, cause baseline lactate should be 1.5 ish around,

um, on the scale of what lactate levels are. One to two is really low. Uh, at rest, you and I sitting here probably, I don't know, 0.8. Yeah. You know, we always have some. Yeah. And then high is like four, like most people are breaking at their threshold around four and like hitting max in the teens. Maybe, um, you know, maybe the best sprinters in the world are hitting low twenties. Yeah. Yeah. You know? So, so that's the scale. Like one is easy, four is hard. So, so it's a, just to put it in perspective for people. So if their lactate levels are up in their warmup, I go, Ooh, we need to back off.

Hmm. Um, and I've had several tests where I guess, and I guess wrong. And how I know I guess wrong is that first stage or lactates are like, and then I just back them right down. And the nice thing about like what happens physiologically when somebody is doing endurance exercise is when the level initially kicks up, lactate levels, heart rate, respiration is going to kick up. Yeah. But then, as they achieve a steady state, those, those lactate levels would stabilize, ventilation would stabilize. And that's why we do the stages, you know, three or four minutes long. Um, if, if we wanted an ideal, just examining lactate test, we'd actually make those stages a little longer.

Let things stabilize off a little more. Right. But, but we're trying to accomplish a lot with basically one test. So we're kind of at a compromise of the, I actually, I made the stages four minutes because I actually run for three and a half. They, you have to, in our protocol, you actually have to stop. You have to have them jump off the treadmill, give them, so I can take their blood sample off their finger. Cause it's really hard to do while somebody's running. So there's actually a 20 or 30 second pause every stage. So I give them a little bit longer so that they get at least three minutes of running in the stage. Um, So the, so the initial speed is calibrated to the, to the fitness level of the individual.

You're designing the lactate threshold portion so that it's 25 ish minutes, six to eight stages of these three to four minutes in length. Athlete starts, they run three to four minutes. They jump off the treadmill for 30 seconds. You take a prick of lactate. They jump back on. We increase the speed. They go on for another three or four minutes, jump off the treadmill. You take a lactate, you take a lactate sample, you, and you repeat that process of increasing the speed, take a lactate sample, increase the speed, take a lactate sample until when? Until I see a deflection in their lactate. And so they'll, there's a few markers that I'm looking for. Um, I look for a one point jump in lactate from one stage to the next. And that's a fairly significant increase from one stage to next. And then I need to see it happen again. So two consecutive stages, uh, with the one point jump. However, that doesn't happen all the time. Yeah. Um, this is like textbook versus reality. It's Renee's life right now.

Often I, the, another criteria I will use as like, okay, they've hit threshold is hitting four millimoles. Yeah. Yeah. There, there's actually quite a few labs that that's their criteria. That's their standard to say, where is LT onset of blood lactate accumulation or LT2 threshold? We use a lot of these terms interchangeably. They might not exactly mean all the same thing, but, um, some labs use 4.0. Um, uh, additional to that, I confirm that they really broke, especially if it's in ambiguous is I'll take them one stage past that. Yeah. Yeah. Because sometimes it's like they're at three and I see the one point jump, they're at three and a half.

And I'm like, ah, I don't. So I'll take them one more. And sometimes that next stage is like 3.8. And I'm like, Oh, we're, we're not there yet. Keep going, keep going. And then the boom, the next stage is like five. Yeah. So I, there's a little bit of an art to it. There, there is an art in, I think an experience and I, but I've gained over these last, you know, decades is confidence of like, we have these bumpers on the criteria and then there's the art of our, our, our protocol is go up by 0.3 miles per hour, every, you know, stage. And sometimes I'm like, oh no, this is going to take 45 minutes. So I'm like 0.5 every stage or the reverse, you know, that, oh, we, we started too aggressive. You know, we're, we're going to hold it at the, you know, a smaller jump in speed. One of the important things about how long that test takes and why we want it to, to take about 25 or 30 minutes in addition to the fatigue thing I mentioned is we need to see that baseline of aerobic work. The, and we want to identify the first tick up in lactate, which we would identify as LT1 and see what is happening, happening metabolically at those lower intensities for an individual, because the additional information that we're, if it was all

about lactate, we wouldn't have the mask on, we wouldn't be collecting their, their, um, the air they're breathing out. But what we're additionally getting is that, uh, metabolic efficiency, if you will, their ability to run on fat as a fuel source. So the value that we're looking at, it's called respiratory exchange ratio. It's the, the ratio of carbon dioxide to oxygen. So if the number, if the number is at 0.7, we know they're burning all fat. That's us right now. It might be at 0.75. Um, if they're at 0.85, we know they're about 50, 50. If they're at 0.9 or higher, it's majority carbohydrate. So there are some trends where, oh, if you're in your, if you're below your, your, uh, LT1 or in your zone two, you should be burning mostly fat. That's actually not true.

Um, it's highly individual. And there's, if we want to go on a, on a tirade of what those parameters are for the individuality of the, you know, metabolic efficiency, if you will, there's, there's a lot, you know, training status, nutritional status. Um, if they popped a gel right before they got on the trimel right before they got on. Yeah. We do that. We see that all the time. Yeah. And then that's, once again, part of the art, you have to calibrate that into it. It's like, okay, this guy had pancakes for breakfast. So this is what we should expect. One instruction I give people is not to eat two to three hours beforehand. Stabilize it off a little bit. Right. Yeah. I also want them to eat two or three hours beforehand. I don't want somebody to come in fasted. If they come in fasted, it's going to skew that efficiency to, to, to, to more fat. Um, and if they are popped a gel right before they get on, it's going to be like a hundred percent carbohydrate. It's going to be like, it's what, what's readily available.

Yeah. So if it's at two or three hours, it's enough for their food to be mostly digested, their blood sugars to have stabilized, and then to be more in a, uh, uh, uh, you, you fed state. Yeah. Okay. So we've got this first part of the test where we're starting them off easy. They're going to slightly above a moderate intensity, but you are saying you're looking at the information coming through predominantly lactate, a little bit of respiratory exchange ratio, and probably a little bit of subjective. This person looks, looks like they could work a little harder or is working too hard. You're saying, okay, this, this part of the stages or this part of the test is done. It's terminated by Renee, the technician based on some sort of criteria, this lactate threshold, uh, portion. Okay. So then what happens? Then we give them a break. Uh, uh, we give them a little bit of a break for a rest. They get to take the mask off, get a sip of water, and we want their lactate levels to come down a little bit because the next portion of the test is the VO2 max portion. And that is what I describe as quick and dirty because we designed the test to take about five to eight minutes.

Again, with that long enough to hit it, but not too long to fatigue. Yeah. So what we do is start them at the speed where they hit their threshold, you know, that 4.0 or the one millimole followed by one millimole jump. If I air on any side, I'm going to air on the slow side. If I'm not sure where to start, I'm going to start them a little slower than a little faster because if they last three minutes on the test, we're probably not going to get a good value. Yep. So quick and dirty is now we're at one minute stages. And in instead of increasing speed, now we increase gradient because most people are going to be limited to just how fast they run. Like it would be dangerous to just have to have to reach terminal velocity.

I've run those tests. They are a lot more dangerous than ours. Right now. It's still very aggressive in my opinion. Yeah. You know, to be running at your threshold pace and then increase one percent gradient every minute until they go to volitional failure. What does that mean? What happens during volitional failure? More often than not, they grab the handrails of the Yeah, grab the handrails and jump off. Yeah. And I'm watching them the whole time. I got my hand on the kill button. And it's as a tester who's done hundreds, I can tell. Yeah, yeah, yeah. There have been very few people who fooled me. Because back to the RER.

When RER is at 1.0, 100% carbohydrate. And it is possible to see an RER of above one. Yeah. And that indicates somebody is hyperventilating. Yeah. And I know when somebody hits one, they're close. Yeah. And most people at their, you know, volitional fatigue, at their peak, let's call it peak VO2. 1.345 in there. The guy who fooled me got to like 1.10. Wow. And I was like, wow. He was a former, like, Division I soccer player. Oh, highly athletic. Yeah, highly athletic in a sport that demanded high anaerobic capacity.

Yeah, yeah, yeah. So, you know, an interesting, you know, side note on there. I've seen some people, I'm going to pick on the ultra runners. Yeah, do it. Who hit their peak VO2 with an RER under one. Yeah. And I see that too often. Yeah. And that, to me, can indicate a couple of different things. Number one, it indicates to me, they might just be glycogen depleted. And they just can't dig that deep. We see that a lot with, like, the fasted training studies where people come into a test fasted. They'll typically undershoot their maximum RER just because of that lack of glycogen availability.

Yeah. That's, like, my biggest suspicion of why that person didn't. And, you know, there's a little bit of maybe they just never have gone there. Sometimes a fear factor of, like, falling off the trail. Yeah. Or the treadmill, sorry. Yeah, exactly. I think that that's probably a smaller factor in there. And, you know, obviously somebody who just doesn't have any top end. Yeah, yeah, yeah. You know, never trains above the zone 2. Sure, yeah. So that's the max is determined by the client. You know, it's however far they can go. And we'll call it peak VO2 because it's the highest they hit on the day.

And is it true peak max VO2? You're parsing words here pretty well, Renee. Well, do we want to discuss how we do our tests at 6,000 feet elevation? Yeah, that's true. That's true. That's another caveat. Yeah, so peak VO2 is what we're getting on the second part of it. Volitional failure. Yes. Athlete jumps off the treadmill. Hopefully we see their highest VO2 number. But it's quick and dirty and hard. Yes. And, you know, every once in a while I actually see that peak VO2 happen in the first part of the test. Yeah. And that goes to the art of it. And, you know, when I take somebody that second, that, not the second, the first stage past their threshold, some people go boom. And they, like, from their threshold to going a little harder than that just maxes them out.

Explosion. Yeah, yeah, yeah. And other people can go a couple of stages past that because maybe their threshold is very low to their maximum. So let's get into that. So we described the two kind of components of the test that we run. Let's get into some prototypes of what you see and how we would interpret those to an athlete and what might be, like, the meaningful takeaways. But before we do that, I want to pause a little bit. Ours isn't the only test in the game. Oh, gosh, no. There's a lot of them, a dozen, maybe, at least. Sure. They're all kind of getting at the same answers. Like, we want to see what lactate threshold is, either via ventilatory threshold or some other combination of that.

And we want to see what our maximum aerobic capabilities are. But there's different ways that you can contrive the stages. You can have a continuous test where you just go start to end, you know, very easy to very hard. And you get all the numbers at once. We do that in our cycling test now. Oh, you do that in the cycling test. We don't divide the two in there. Oh, wow. I changed that a few years ago. Oh, okay. Oh, I remember that now. I did that in large part to get that complete curve. Yeah, yeah. I wanted to see what the lactate value in the oxygen consumption at one stage past, two stage past. And after doing, you know, so many tests after so many years, the difference between the three, in cycling tests we use three-minute protocols.

Yeah. It was more simple, straightforward. And I like the more complete data of the whole profile there. I would consider that for the running, too. But I think we'd have to use a different protocol, speaking of different protocols, that didn't just go terminal velocity.

Yeah. I was just going to mention that. That's the trickiest issue with doing a continuous graded exercise test on the running side is that if all you're using is speed, eventually speed becomes a limiter and you don't want that to happen. So then you have to introduce grade. And then you have to make this decision point in real time in terms of when are you going to switch from speed to grade. I've seen labs that set that whole thing out in advance of the test, like based on how you would do it. Athletes coming in with a 35-minute 10K PR. So we're going to start them at this speed. And then this is going to be the speed grade inflection point right here. But in my observation, at least, which is limited in that test, admittedly, the flexibility of the practitioner to change that based on what they're seeing becomes much more limited.

Because once you start, it's just kind of like there's no you got to just kind of run the protocol at that point. Exactly. The consistency of the protocol is important because if you're always changing the variables, then you're like, what am I getting? And our test procedures originated from what they're using at the USOC lab. And that lab is testing a very specific athlete group. Right. You know, they're only getting elite athletes. They're getting the best of the best. And, you know, our running protocol is very geared towards that, like, fast roadrunner. Yeah, the jumps are hard. Yeah. 40 seconds of miles, a big jump.

Right. And to that end, we modified our cycling protocols a few, several years ago when, you know, it just wasn't working. Yeah. You know. It's too hard. The jumps are too hard. The jumps were too hard. Yeah. So we, you know, we still have a standard protocol. Yeah. It's for basically kind of like three different groups. Yeah. If we think your threshold is going to be at this absolute wattage, not watts per kilo. If we think it's going to be at this absolute wattage. Yeah. Well, let me, so this is why. I'm a petite female, but I'm a way better than average cyclist. Yeah. My threshold is typically under 200 watts.

I coach a gentleman who's 70 years old, who weighs 180 pounds, whose threshold is 150 watts. So he and I, like, if we did it by watts per kilo, it's going to be too aggressive for him. Yeah. It might be appropriate for me. Anyway, we have kind of like, if we think your threshold is going to occur at 180 to 200 watts, this protocol, if we think it's going to be this, you know. So we use smaller, we use a slower, lower wattage to start and smaller jumps, the lower we expect their threshold to be on absolute wattage. And there needs to be some degree of flexibility within any lab that's doing this stuff to accommodate for that, because you're absolutely right.

The majority, maybe all, certainly the majority, maybe the vast majority of the tests that are out there were conceived underneath the same cohort that you just described. Elite level athletes who have a vastly different aerobic context or aerobic capacity, more aerobic capacity than the normal people kind of walking into the lab. And so you have to, like, tailor it to it. It's not the same, like, Cooper test or bulky test that you would see in a health club type of setting. Which is also not appropriate for our sport group. Exactly. They're too easy. Too easy. And, you know, test geared for the elite, too aggressive. And even in our lab, the athletes I've tested in the CTS lab are, like, everybody from, I'm trying to think of what professional cyclists I've recently tested, but plenty of professional cyclists.

Plenty of above average age group athletes. You know, and then, you know, most recently, you know, a couple of people over 65. Yeah, yeah. And I would classify as, you know, more sedentary. Yeah. So there isn't a one-size-fits-all. Yeah. Yeah. But having a standard protocol is important for that criteria in a minimum using the same protocol for an individual. That if I've modified a protocol for an individual, that if they come back to test, that I use that same protocol.

Yeah. So you can, you know, compare one to one. I mean, I guess that's with almost any lab test or field test is that there is a standard course or a standard criteria. Yep. Yep. You know, we're going to earmark this for later because I know we want to start this brainstorming session in a public forum, which we'll see how well that goes. But there's also the context of what sport or what discipline is the test intended for. So going back to the initial example, ours was developed over at the USOPC, which used to be the U.S. Olympic Training Center. I always get the acronyms confused now. Um, the context for that were 5,000, 10,000 meter and marathon running athletes.

Yeah. So the way that the test was originally constructed was to accentuate what we thought we, they thought it's because it wasn't me, what they thought at the time were kind of the hero variables, right? Running economy, speed, lactate threshold, VO2 max. Like you combine those things together and you can do a lot of stuff with it in, in that athletic context. When you start to drift outside of that specific athletic context, 5,000 meter, 10,000 meter in marathon running, the, the, not the validity of the test, but the data that you're getting from the test in terms of its correlation to performance may or not be as highly correlated. And one of the things we're starting to appreciate about ultra marathon is there is start to, there's starting to be this decoupling between what I'll call the classic variables, namely lactate threshold and VO2 max.

And how they are certainly more poorly correlated at the ultra marathon distance, um, uh, as compared to those traditional distances. You see this also in the development of these like one-off protocols, right? We had, we were talking off air. I had Inigo San Milan, uh, on my, uh, on my podcast about a year ago and he developed one that's pretty specific towards true to French or stage race cyclists. Like, I mean, he's, that's his wheelhouse, right? He's kind of developed it for that. It's longer stages. It's what he thinks is important for their success. And he wants to kind of test for that. You see that manipulated as well for a certain athletic context. Yes. Same thing with triathlon, right? Or similar thing with triathlon. Okay. So we've got our test, our standard test, lactate threshold section VO2 max section.

Yes. Athletes done. They may or may not puke because the test is really hard. We have some pukers every once in a while. Not too many pukers, plenty of droolers. A lot of droolers. Yeah. You pull the mask out and it gets kind of gross. Yes. Gross. Um, so they finished the test. They get cooled down. They, they recombobulate. Renee goes to the computer and crunches the numbers. Take us through the interpretation. Like what are the things that you are predominantly looking at? I know you've got some, uh, graphs and things like that, that you want to shuffle through here. But when you initially start that, what are like the, the big shining stars that you want to bring to the forefront initially considering a test goes to plan, which you can comment on how often that actually happens.

Right. Well, as I'm analyzing data, pick out the big two, the, what was their peak VO2? What was their lactate threshold or LT2? Um, we're identifying it by a pace and probably more applicable is by heart rate. Okay. Um, cause not even many road racers are training by pace. You know, you're on variable terrain and pace is not always, um, the best metric, but we do identify it. Yeah. And then something that we have done newly over the last four or five years here is, um, identify the first inflection point of lactate where that's the, we, we look for those first two, three or four baseline stages.

And what we'll see is lactate stays very stable. 1.8, 1.8, 1.8, or 1.6, 1.8. Even though you're increasing the speed. Yes. As we're increasing the speed between the first, you know, three or four stages, um, we see that baseline where it's getting harder, but it's not by lactate. It's not increasing. Do we want to explain why? Go ahead. Why should it not be increasing? It should not be increasing because somebody should be able to handle that intensity by aerobic metabolism in the mitochondria of the slow twitch muscle fibers. Um, lactate. Lactate's a byproduct of metabolism. We're always making some.

It's specifically the byproduct of carbohydrate metabolism. As exercise intensity increases, so does carbohydrate metabolism. And in particular, when you get to moderate to high intensity, carbohydrate becomes the predominant substrate. And when somebody gets to that moderate or high intensity is when we see lactate levels go from baseline to a little higher. And when they're using virtually all carbohydrate is when we see that final break point threshold, the point above which they're making lactate at such a fast rate, they can't get rid of it as fast as we make it.

Because we recycle lactate. We use it as a fuel source in our slow twitch muscle fibers in the mitochondria, but we can only use it so fast. So when energy demands are very, very high, lactate production is very high and the clearing rate of it can't keep up. And then we see an accumulation. So it's actually not the lactate that's causing the fatigue issues, but it's the metabolic processes that are happening when lactates are high. Which is important when we're not going to get into this discussion, when we get into lactate buffers and things like that. That's beyond the scope of this. But you're using lactate essentially as a marker of metabolism.

Exactly. Right. What we can get from a test in the second parts of I've identified the LT1, the lactate threshold, and I use those values to set somebody's training ranges. Back in the olden days, we used to even, with our lab test, only identify LT2 and then use raw percentages. Saying, oh, zone 2 is 75% of that and zone 4 is 90% of that. There's one anchor point and we built around the anchor point. Yes. That's, yes. And now with a little bit more knowledge and savvy and doing things better, I use the LT1, LT2 to establish their ranges that below LT1 is where zone 2 falls.

And then between LT1 and that final break, LT2 is where zone 3 exists, or tempo, tempo and cycling. And then, you know, right around that break point is that zone 4. And then above the break point is VO2 max intensity. So, I use those individualized specific inflection points on the lactate curve to set somebody's specific ranges. Whether it's pace, heart rate. Pace, heart rate. However you want to do it. Power. Yeah. Yeah. Yeah. So, zone construction is one thing that you're getting out of this, and you're kind of backing into it from identifying lactate threshold break point 1, lactate threshold break point 2.

Yes. And additionally, which we haven't even talked about, maximal lactate steady state. Mm-hmm. Which is a point that's usually around LT2. But for a lot of people, there's a middle point between the two, LT1 and 2, or onset of blood lactate accumulation. Maximal lactate steady state describes the point at which buffering and clearing and production are kind of balanced. And it would be somebody's hour of power, if you will. There's a lot that... How fast can you go for an hour? How fast can you go for an hour? Which usually occurs close to LT2, as Carmichael Training Systems Labs identifies LT2.

Yeah. But maximum lactate steady state, for a lot of people, is in the mid-threes. It's that hard, but not quite... You've got high lactate levels, but you're not accumulating anymore. There you go. Yeah. So, we identify that as well. So, the zone construction. And then the additional information that we have more recently started pulling out, because it's very buzzy. And we've always had this information, but we never examined it. It is very interesting to me. Yeah. Is there carbohydrate and fat metabolism at those...at every speed? Mm-hmm. And that helps...

Let's say somebody is, you know, normally fed, not overfed or fasted, that it indicates how metabolically efficient they are. How good are they at using fat as a fuel source at low to moderate intensity? My observation from our typical clientele is most people start around 50-50. And, you know, carbohydrate contribution goes up from there. Certainly not down. Certainly not down. With very well-trained athletes who have... Very well-trained endurance athletes.

Mm-hmm. Especially those ones who have emphasized, you know, deep aerobic base. You know, those Tour de France riders. Yeah, yeah, yeah. You know, elite ultra runners who have, you know, tremendous aerobic base. Tremendous mitochondrial density and efficiency. I will see them be able to use fat as the predominant fuel source through more stages. More stages in the early part of the test. Everyone, as they get to higher lactate levels, are going to be burning more carbohydrate than fat. And that just kind of goes back to what we said, that lactate production is from the breakdown of carbohydrates.

So if lactate levels are going up, it means you're burning more carbohydrates. So riddle me this, Renee. So we initially kind of started the one of the value proposition is zone construction. Yes. And you can certainly take, in quotes, energy system approach, right? Even though they're not switches, we know they're dimmer. We use those analogies and things like that. I think this audience understands this. But we're using the results of the test to start to set that initial construction. Run at this heart rate, this pace, this RPE to be easy. This is medium. This is hard. These are going to do things differently from a bioenergetic standpoint. But since you also have the carbohydrate and fat metabolism, can you also set zones around, this is your fat burning range.

And if you want to increase your fat burning capacity, you should train near that range. Is that a reasonable value proposition? Because that's something a lot of people are interested in. Fat burning is all the rage. It's a new year. People are doing this stuff. Is that a reasonable proposition? Like, can you extract enough value out of the test to say, if you did this in the correct way, we can somehow shift this metabolic profile or become more metabolically efficient to use those terms? I can admit I don't know everything. And I'm still learning. And I'll give you my take on it. It depends. On what? On what? So, this lady here, I'm looking at a test where stage one, 75% carbohydrate off the bat.

Whoa. Stage two, 83, stage four. Coming in hot. Coming in hot. She's a sugar burner. Yeah, yeah. If she tries to, you know, train at her, quote, fat max. She walking. Yeah. Yeah, yeah. And there's a value proposition of how much benefit is she getting from maximizing her fat metabolism versus just getting fitter? Yeah. So, you know, I think you will agree fitness trumps everything. Yeah. So, it's a value proposition. And I'd also say that training at that level isn't the only way to manipulate it because you can manipulate it by diet as well. Now, before anybody jumps on a fasted training bandwagon to maximize their fat burning.

Because you can see that result in the test. Somebody comes in fasted, they're going to have probably the inverse of sugar burner that you're looking at right now. Right. But they're probably going slower too because they don't have any carbohydrates to use. So, that concept of fat max, maximum fat burning potential, being more metabolically efficient, I think has been abused in the sports arena. In particular, with the marginal gain that you get from being a little bit more metabolically efficient, meaning that you're burning maybe 100 more calories per hour from fat. So, the reason why we want to be better fat burners, more efficient fat burners, is not so we can lose weight.

That's the abuse I see is people like, oh, my fat burning zone and I'm going to lose so much weight while I'm doing this workout. That's not what it's about. It's about being able to run on our more unlimited supply of fat. You know, even the leanest athlete can do multiple marathons on our stored fat and we have limited storage carbohydrates. So, in long distance events, we want to preserve those carbohydrates as long as we can. If I get a 10K runner, maybe even a marathoner, I don't care. Yeah. Well, I shouldn't say I don't care, but it's very insignificant how metabolically efficient a 10K runner is.

Yeah. Because they're not limited. Their events are so short, they're not limited by, you know, their carbohydrates. Yep. Or, you know, the limiting factor is not how efficient they are at burning fat as a real source. But is it, let's kind of like circle it back though. Is it a reasonable proposition that if you can identify fat max and that's not what our, that's going back to my earlier point, the construction of this test is not, was not intended to bring out the maximum fat burning capacity of the athlete. It was meant to bring out lactate threshold and VO2 max going back to that original Olympic proposition. But, but we do have those numbers and there are tests out there that are more specifically designed to get at a fat burning curve.

Yes. Is it a reasonable proposition to say, okay, now that we've identified this, instead of using a zone based construction, we're just going to train around just essentially the biochemistry of things, right? How much you are, how much you are burning fat in order to accentuate that potential property. Is that a reasonable proposition or does fitness just kind of like trump everything else? Tough question. It is. Because you know you can push and pull on the, on, on, on the, on the metabolics of things. Right. Um, you know, mitochondrial density trumps all, but, but greater, greater mitochondrial density is also created by working in those lower intensity ranges where you're going to see the, you know, fat, the, the maximum, you know, fat burning potential of somebody.

I don't prescribe by, oh, this is your, your, your, your fat max range range. I more use it as a, an identifier to say, this is your strength or limiter. Yeah. Again, if I had the crit right racer and they're a sugar burner, if you will, it's fine. Yeah. If I have, um, uh, you know, ultra marathoner or, you know, somebody getting ready for the unbound gravel race and they are quote sugar burner. I encourage them to modify their training, do more low zone two base training and to train, uh, train that those ways without overfeeding carbohydrate.

Yeah. And I, I hesitated, I hesitated, I hesitated on that because I don't want anybody to take away from this train low carbohydrate, eat low carbohydrate, train fasted. It's just the difference when you're doing tempo intervals, running intervals and, uh, high intensity intervals. You need to take gels in, in, in sugar while you're doing those workouts because the intensity is so high. That's what you're wearing through. You're also typically in a low carbohydrate state by the end of it anyway. So why would you try to manipulate it anymore? That's what I've always got. If you're going out for a three or four hour lower intensity effort, you don't need to shove gels down your throat.

You know, that's when you can eat more like mixed nutrition and you obviously don't need to, to maybe consume at such a high rate. One year caloric expenditure per hour is lower. That's also another thing that we determined in our test, but we are, we are giving them at this heart rate, you're burning 543 calories per hour and 456 come from carbohydrate and 90 come from fat. So we're getting those splits from measuring their, uh, so we, that also can help them with their nutrition because it's a little bit more accurate. Yeah. Of how many calories they're burning per hour, how many are from carbohydrate, how many for, from fat. So it helps them identify their nutrition, but back to the point of training and, and do you have to train around your maximum fat burning range or, or data heart rate?

I don't, I don't, I don't believe so, but I believe if you train lower intensity and don't over fuel with carbohydrate that you can shift that over time. But the main shift isn't coming from the like nutritional side or training at that specific heart rate is just the volume of work at the low intensity. So we started skipping directly to the fat burning thing. That's probably an egregious error on my part from a structural standpoint, but let's get, let's recap a little bit. One of the values that you get out of the output is the range construction, right? You get, you have these ranges, we know what's easy, medium and hard, however you want to delineate it.

We use a five zone or range system. You'll see seven, you'll see nine, you'll see three, you'll see what's the most you've ever seen. 12. Where you get into like seven, seven, like seven C, like seven ABC or something. So that's 12. Once you get into that, you can't delineate, once you delineate seven into three components, that means 10. Right. Right. But anyway, my point with that is, is one of the, one of the value propositions is establishing the ranges. But the other one that we have alluded to that I want to dig into next is the, the considerations that you then take into training. What data can you extract from the test to say, you know what, you need to do more of this, less of this, a medium amount of this type of flavor.

Walk us through your thought process on that. Because I, in my estimation, Renee, that's like the advanced data download. Like those are the really good practitioners that have done it for many years, that have seen kind of the profiles that start to, that start to show themselves across many different athletes. And then they can kind of combine it with what they're doing and all this other stuff. Where do you start with that? Because that's a big whole rabbit's wormhole of stuff. So you and I got caught up in the buzzy talk. Yeah, exactly. And we get down the rabbit hole of fat facts and burn it. And it's such a marginal gain. Yeah. Like our friend Clayton Feldman, he likes to say minimal gain.

Sure. And we're after maximal gain. Yeah. Identifying where's my upper limit to where is my sustainable threshold. That's a maximal gain. Where's my potential? Yeah. So I'm glad that you brought us back to what matters and what I don't believe any athlete has ever come to me with or of the question they're trying to discover is shape of their curve. Yeah. How does that lactate progress? We talked about it starts low and a baseline and then it pops one millimole, one millimole. That is a textbook. Yeah. Normal curve, if you will. Normal, maybe not average. Maybe not average. Where, you know, after that, you know, that first tick up of lactate usually is about a point jump.

Yeah, yeah. And then after that, maybe another point jump until we get to that second threshold. That's pretty classic. Yeah, yeah. I see a lot of people in our lab who are of, you know, varying levels of fitness and that have what I would call linear curve where just from stage one to the end ticks up every single stage. Half a millimole every single stage. What do those athletes do? Take two weeks off and quit. Take two. No. Those people are saying you train more and specifically train. They need base. They need a bigger aerobic base. So low intensity. Low intensity.

And why is that? Like why? What within that half a millimole jump on every stage leads you, the practitioner, to say, we need to give you a lot of low intensity volume. Like what metabolically, physiologically are they trying to accomplish? Greater mitochondrial density. Coming back to that. They're slow twitch muscle fibers. That they can be more aerobically efficient. And the most effective way to do that is training at low intensity. Yeah. So that's one profile. Yes. The slow tick up. What's it? Oh, my gosh. You've got four of them written down on your sheet. What's the next one? Those are I knew you were going to come to the table with those. Another one is, well, the other one is what we call steep curve.

Low, low, low, low, low, low, low. Boom. Boom. Yeah. That's what we see in really well conditioned athletes or Tour de France athletes is that they have very low lactate production. And they can go for a long, long time before their lactate spikes. But when it does, it spikes high. So that indicates that they are tremendously aerobically efficient. They have great capacity of their slow twitch fibers to produce energy. But then because it can also spike high, they have shown that they have like a high VO2 max. They can have a great glycolytic capacity to do those higher intensities. And they're finishing at 10 millimoles.

Yeah. So the sister to that or ugly cousin to that is the low, low, low, low, low, low. And then just a small bump up at the end. So there's no, there's not a big increase in lactate. Not a big increase in lactate. A flat curve, if you will. Yeah, yeah. So they, at first they appear really well conditioned. But then at max, they're hitting four, five, six millimoles. Yeah, this is ultra runner 101. Ultra runner 101. And this is also that person that might potentially be glycogen depleted. Yeah, sure. They just can't go. Or certainly has, certainly like has no top end.

Has, so it appears good. But the evidence that comes at the end is bad. So that person probably needs to eat more carbohydrate. It also needs to do some intervals. Do some hard intervals. Like, let's go. One minute, two minute. Harsh and go. Let's like, you know, put some oomph into it. Yeah. This, so what Renee is describing, actually described in the first edition of my book, not the second edition. So this person, this athlete who I'm going to out right now would not mind me because it's already kind of been out. But when we brought Tim Olson into our lab, he had that profile. And that was my, it was a very easy response. You just need to do more in high intensity work.

That's your biggest opportunity to gain right now. You've done all the low intensity stuff. It's very clear from the bioenergetics of what's going on. Very clear from the lactate profile that you could continue to do low intensity work till the cows come home. And it may make it a little bit more of a difference, right? Total volume matters and all that stuff. But if you want the lowest hanging fruit, let's use a nutrition analogy. Let's just do some high intensity work first and get a little bit of separation. Right. That's because that's a clear like red flag limiter. Yeah, exactly. Clear limiter. Yep. One more. It's not on my little chart, but I've got an example here. Like a prolonged, basically a prolonged zone three. Mm-hmm. Uh, they, their lactate does have that nice, uh, baseline in the jump from, uh, baseline to maybe a point or two up.

But then they have maybe two or even three stages where they're just like at three, three and a half millimoles. Kind of a prolonged, moderately high level of lactate. Um, often those people kind of don't always have the best top end either. Mm-hmm. But that, I see probably more in cycling than any other sport because they just are, love tempo training. Yeah, yeah, yeah. So tempo, people like tempo because it's just hard enough that it feels like you're doing something. And that, I know you're going to ask me about sensations, but that sensation of, oh, I feel it now.

Yeah. But it's not too hard. Yeah. That's tempo. That's your, that's what's occurring when your lactates are at, you know, two, three, three and a half millimoles. But it's not so hard that it's, people become adverse to it. Right. But it, there is value to it. Yeah. But it's not helping move the LT1 to a faster speed or greater wattage. And it's also not moving the actual threshold point out. Yeah. So, like I said, there's value to it because it is for a lot of athletes doing two to three hour races. It's their race pace. Yeah, totally. So, we've got these two kind of like basic value propositions, right?

The zone construction and then identifying something that's going on within the test that's going to drive the training process. Immediately leaving the test in a lot of cases. Like you have information now. I want to do this. Yeah. And I'm going to go and do that tomorrow based on strengths and weaknesses, kind of however you want to mention it. Let's talk a little bit about the value of coming back. Yeah. Because for many athletes, they want to satiate, what's my VO2 max number? Like I want to know that. What's my fat max number? Like whatever kind of like buzzword it is. But can you describe how those fundamental value propositions change for an athlete that can come back and test again?

And what sort of frequency would you like to see that at? Yeah. It's a really good question. It's not terribly frequently used. I would say our most common is one and done. What's, how common? Like 80%, 90%, 95%? Yeah. Yeah. I'd say that. 90. And I think that's the athlete who is self-coached. Sure. Honestly. They're like, what's my threshold? Because they believe it's like a permanent state. Or what's my VO2 max? It's a permanent state. You know, by heart rate, it's actually doesn't really, it's not very volatile by heart rate. VO2 max is trainable, but, you know, trainable by 5%, maybe 10%.

But you're not using that much in the training. Right. At all, maybe. Right. It's a bragging right to say, oh, I came back and I'm this many points higher. Or, you know, you can boost your VO2 max by losing 10 pounds too. Yeah, totally. The value proposition is answering the question, is my training working? Am I doing what I think I was doing in my training? Back to the, has their substrate utilization changed at that lower, you know, zone 2, below LT1 pace? Mm-hmm. Have they moved their curve to the, right.

That indicates that they're going at a faster pace before all the break points happen. And have they either moved their LT closer to their max or, you know, expanded their max? And there is a little bit of push and pull. That if immediately today we increased your VO2 max but didn't train your threshold, you beat out a lower percent, theoretically. Yeah. So, I think it helps answers, am I on the right track? And what should I do next? You know, that, you know, time course for testing in a perfect world, more perfect.

I might suggest that somebody comes in and tests. They could come in and test before they start training, like, after they're, like, off-season. Yeah, yeah. That would be great, but I'd actually think it's more important to come in before they start their more specific training. That identification of LT1, am I doing my base training easy enough? I think that's easy enough for people to figure out without coming in to do a test. So, I'd rather see them come after that, you know, base training before they get into more, maybe there's, they could answer the question at the end of their base phase.

Do I need more base? Yeah, yeah, yeah. Or do I need to move on to threshold development? Yeah, I think what you're painting is, is across these two things that we identified, the zone construction and what do you do from a training perspective, the latter becomes highlighted more as you get more tests in. Because, yeah, the zone construction is going to change, right? Especially with athletes who have really big, like, peaks and valleys. We all know those people, they get really unfit and they get really fit and they get really unfit. And you can, testing isn't the only way to calibrate those ranges, right? You can always calibrate it with training and field testing and a whole myriad of things that you don't know this. But Adam and I talked about that a couple of days ago. That podcast will be released before this podcast. It's probably going to be, actually, no, it's out today. I just now remembered.

Oh, you listened to it this morning. Thank you, Renee. Get one down mode. So Adam and I talked a little bit about that during our podcast is how to kind of construct those ranges and what the difference is. But what I'm hearing from you is the ongoing piece is more centered around how is your training actually affecting your physiology? Yes. Is it working the way I think I'm working? And do I need more of X? Because it's not done. I'm not done progressing yet. Or am I ready to move on to why? Okay. Here is the level 404 question for you since you're a level 404 tester. How clear are those answers? I mean, you get an athlete, you know, okay, we need to work on threshold.

They go out. They go work on threshold. They come back and they test. But when you do the compare and contrast, athlete A to three months or four months later, athlete A, how clear does that cause and effect relationship typically show up? It depends. On. On. On. On. On. On. This is a running joke, by the way. Like, we use this, this, this, we use this phrase in coaching, it depends. And I never let anybody get away with it because it always depends on something. So, Renee can't use it as a cop out. So, that level 404. Absolutely. I can look at a test and I can identify somebody's strengths and limiters and come up with some good protocols to address those based on their, the demands of their, their sport, their, their, their event.

You know, based on that, how many people come back and test? Those people who come back and test, they come back and test, like, randomly. Yeah. They come back and, and often it's like, you know, maybe it's once every year or two years, three years, January 1st. Yeah. So, I'm seeing them at the same state over and over again. So, I don't have actually a lot of data of that really nice testing. I would say two, two, three to four times a year. Like, four times a year would be like magic. Yeah. Yeah. Yeah. Like, beginning, end of the first part.

And then as they're, you know, right before their specialization, then maybe right at their peak of fitness. So, you know what they're, like, got to at the end. That, that would be wonderful. I've never seen that. Yeah. I mean, if, for sure, you know, like, go to, what, three miles over there, the Olympic Training Center. You know, they have those tests for, you know, Chloe Daigert and everybody at the, you know, resident athlete program and stuff. But, I would love to see it, but I don't see it. Yeah. And that's what, that's one of the pictures that I'm trying to paint is sometimes you, the testing frequency has to be such that it actually gives you a realistic window into that. You have to have a little bit, I hate to use this being like evidence-based practitioners or whatever we call ourselves these days.

You have to have a little bit of faith. The training is actually going to push and pull on the things that you want it to. And we have a reasonable degree of confidence that it's going to because we've been doing it for a while. And we know how physiology works and things like that. But just because of the limitations of finding a lab and then going into a lab and carving the training out and rearranging your training around doing the test. I mean, that's a realistic consideration as well to make sure that you have an apples to apples comparison. Sometimes these nice picture perfect scenarios that we dream up in our heads to where we can trace a cause and effect don't actually pan out just because of the logistics of it. I would, you know, for anybody out there listening, they're thinking about doing a test. It's absolutely valuable to come in and do it once because you get some insights on you as the athlete, period.

There's some characteristics that like genetically people just can't get rid of. You know, if there are obviously things that you can train, you can train your limiter and your strengths. But if you have a limiters, you have like a natural genetic pre, often a natural genetic predisposition towards I have a really high VO2 max or a really high inner work capacity. Or, you know, the opposite, really good at long sustained efforts, if you will. But those insights and the snapshots of who am I as the athlete, where am I like kind of just the starting point is really valuable in my opinion. If you have the chance to come back, that's wonderful. I'd also propose that maybe you don't have to come back and do the full test.

I get a lot from just, I can test myself, just from doing a lactate profile. Yeah, yeah. You know, that's, you know, half the cost and not as invasive. Yeah. Not as difficult or interruptive of the training process. Right. What I'll also say to that is we kind of presented some like atypical scenarios. Like if you have your little stair step test and you have, you know, a really close, you know, your, your lactate threshold compared to your VO2 max is very, very close. It's at 96% or whatever. There's also value. And I just recently had this with one of my athletes that came in the lab. If you have a normal profile, what that can actually tell you a lot of what to do as well.

You don't have to focus on one thing or the other. You can kind of focus on the demands of the event and arrange your training architecture around there. Like there's a lot of value in that because you can kind of tease that out with the training data. If you've got good training data with an athlete, but actually having it and saying, yep, this is exactly what we need to do. It breeds a lot of confidence in the, even in the normal circumstance. Yeah, you're right. We did focus a lot on the anomalies and whatnot, but, you know, certainly there's a lot of value into your good. Keep doing what you're doing. Keep doing what you're doing. Yeah. Stay out of the way. A lot of that is, a lot of coaching is that just stay out of the way. Okay. We're going to brainstorm a little bit, but is there anything else we need to go over on the testing side of things before we do?

We're going to get into the really theoretical weeds. No, I think we covered it because I'm glad we circled back to the shape of the curves. It goes over most people's heads. You know, unless I'm, you know, working with an athlete who's done a lot of testing or has a lot of knowledge or, you know, occasionally, you know, I get in contact with an athlete's coach. Yeah. Who has, you know, some savvy knowledge of that. But giving, you know, giving an athlete more specific training direction. Yeah. Because they're coming in for those, like, hero values, right?

Yeah. I think the hero is the training direction. Yeah. I mean, if you're out, if any athlete asks me, should I test or not, the answer to that question always falls into how much information do I think I want to direct the training? And if I'm going to get good information to direct the training, great. And if not, and some of that is just the initial value proposition of the zone construction. Not that it's irrelevant, but it loses its relevancy in an ultra running context because we're using so much rating of perceived exertion to describe and prescribe the intensity side of things. Because, like I said, it just puts more of a highlight on the, this is your bioenergetic profile. This is how we're going to manipulate it in the future in order to make maximal gains.

Exactly. Because if it was only to figure out what's my threshold. Yeah. You can do that. Go, you know, run up Gold Camp Road. Yeah. As hard as you can. Go do a half marathon as hard as you can. Tell me what your heart rate was. Yeah, yeah, yeah. We figure out your, you know, theoretically your pace or whatever. I mean, we can backtrack to what your VO2 is on, you know, minute per mile. Like, and we also know that it's not, it doesn't affect training parameters. Yeah, right. You know your VO2 max is 70. Like, that doesn't affect training at all. Yeah. And I just want to interject in here, there, that you don't have to come in the lab, like we said.

Mm-hmm. But please do not use 220 minus your heart rate to figure out anything. Because I've had several people come into the lab where that's what they were using. Yeah. So you don't have to come in the lab to figure out what your maximal sustainable heart rate is. It's not really relevant what your peak heart rate is. Yeah. It's important what your maximal sustainable heart rate is. Mm-hmm. And if that's your first step into more tailored training, that is awesome. Yeah. If you just kind of know what your maximal sustainable heart rate is by figuring it out, like, you can figure it out by, like, when I go hard. I can only go for this long at this heart rate. Right. Yeah. And that, in using, like, raw percentages of 75% is zone two and 85% is zone three, that's a wonderful way to start.

And then if you want to take your training to the next level because you hit a plateau or you just have, you know, more ambitious goals, you want to figure out more, then the lab is a wonderful next step to figuring out those things. Because what you can't figure out from doing that, you know, field threshold test we just talked about is what's happening at the bioenergy level. Where is the top of my zone two? Yeah, exactly. What is the shape of my lactate curve? What strengths and limiters do I have on the metabolic side? Yeah. So it answers more questions.

But I do want to emphasize not everybody needs to come to the lab. I mean, that's a really good way to put it. It is a finer tooth comb that we can put a lot of these things through that you can do just, as we mentioned in Adam's podcast, through field testing, through looking at workout data, through a whole host of other means. We can get close. Lab testing will get it even closer. Whether you need closer, closer is kind of, it's not individual, but it's kind of almost a progressive, right? Are you at that stage of your athletic career to need that level of precision? Yeah. If somebody is, you know, a total beginner, never had a heart rate monitor before, period. Just go run. Right. Because I've had those people who are total beginners and, you know, I will, you know, perform their tests and thank you, but it might be over what they need.

Well, it's a curiosity satiation too, which is, there's value in that, right? I want to satiate my curiosity and get this as precise as possible. And that helps fuel their motivation somehow. There's, I can see there being some value in that. Okay. It's brainstorm time. Yes. Okay. Shake it out a little bit. We've been going for a while. Okay. So I asked Renee to, to think about this in advance. Cause I think this is a cool, this is a cool problem. One of the things we touched on throughout the course of the podcast is the, the, the protocol for these tests were designed around a really specific cohort, right? Elite level endurance athletes. Yes. And specifically on the running, running side, elite level 5k, 10k marathon types of athletes. Yes. Irrespective of what protocol is being used. That's typically how the protocol is arranged around.

And the reason for that is, is the hero metrics that we pull out of that are relevant to that sport or relevant to those sports and those, uh, in those types of disciplines. This is an ultra marathon audience, right? Largely an ultra marathon audience. We'll get some ultra endurance cyclists and maybe a few like regular marathon runners. But I want to try to make this somehow kind of like theoretically applicable directly to the audience in a way that kind of gets everybody to think. Knowing what you know about the sport, Renee, and I can come in as well. I know a little bit about the sport too. What would you do differently with the test? Cause you already mentioned that you redesigned it a couple of times just based on our evolution and knowledge.

Is there anything you would do differently? And you can get as general or specific as you want to on this with that specific audience and ultra marathon audience. The, the, the duration domain is over six hours up to 24 hours and maybe longer. What do we need to know about that audience that would change what the tests look like? Probably the biggest factor or change point that, that I would do is, uh, the speed and gradient in particular on the, well, actually on both tests, but, um, the, as we were talking about, it is designed for people who run pretty fast. The speed is high. The speed is high and, um, it's flat running and a lot of the ultra distance people, like they don't run that fast.

Speed is a limiting factor in the testing. It's a limiting factor in the testing protocol. So using, um, you know, potentially a fast walking speed and utilizing gradient as the increase to, to the intensity through the lactate portion. That would be like a modified, what do you go? Balkey test. Balkey test. Um, I think that that would be more appropriate for many of the ultra runners. And then also we get some people who are just not as conditioned. So it's a, I think it's a better protocol for people who are at a lower fitness level as well.

Um, so that would be the, that'd be one, uh, change of the protocol. Keeping walking is the mode though. Um, walking. We call it power hiking, by the way, not to denigrate the, the mode or the audience. I thought it was called coupaling. Not coupaling. That's an internal joke that we have. We don't need to get into that. Power, power, power hiking just so we don't offend people. Okay, power hiking. Thank you. No, I mean, I want to use correct terminology. It's not, no, it's not incorrect. It's just, doesn't make the audience feel as bad. Okay. Um, so I think a power walking protocol would be appropriate for a lot of people that come through the CTS lab and includes many of the ultra runners. And so in that case, you would still get, would you get, I mean, you're saying this, I think that I think I'm answering my own question.

You think you would still get valid lactate threshold values, even though the mode has been changed. I'm trying to work through this in my head in real time. But do you think that that would affect like how you would interpret the lactate curve, I guess is what I'm saying, because the mode is different. That's a really good question. And my answer is, you know, intensity is intensity. Effort is effort. If we can find that, what I don't know yet is what jumps are appropriate to get somebody to go intense enough. I know, I would assume many athletes who might have a VO2 max under 40 could hit, hit those values on a walking protocol.

But maybe if your VO2 max is 65, you're going to have to run. It would be super steep. Yeah. I mean, that it just wouldn't be intense enough. Yeah, yeah. If we can have the intensity at the right level for that individual athlete, then yes. One of the limiters of our test and something that's happened several times is I have to start somebody walking. Yeah. Because what is it like, what, four and a half miles an hour or so is where most people have to start running. Yeah. And at that pace, I see some athletes, their lactate levels are just too high. They're like way over baseline. So I have to start them walking. And that jump from walking to running is like a pretty significant increase in metabolic demand.

Even in our own protocol, if we keep it at this level and somebody can't run at baseline, what's appropriate? Yeah. Here's the confounder with that, though, because we're in a brainstorm session. I think that if you wanted to use a heart rate based zone construction, and I think the literature would back this up as well. You would have to have different heart rate ranges according to mode. Yeah. Walking and running. And you could even make it a case where it's, and we do this a little bit on the cycling side, you remember, you could even make the case that your heart rate ranges can be slightly different in a flat level condition versus an uphill condition. And not to say that, you know, that that would be the most important thing that you get out of the test.

But when we're talking about the zone construction of it, that's at least one constraint. One of the things that actually constrains ultra that I just now thought of as you were going through that is it does contain a mix of modes. It does contain walking and running. And fundamentally, if you want to consider if most people would consider those two forms of exercise to two different forms of exercise or two different forms of locomotion. I've always pitched it as four different sports, uphill running, downhill running, walking and walking uphill. But I don't think that that's necessary from a from a testing standpoint. But I guess my point with that is, is, is that if we're looking at trying to make it mode specific and ultra, you have to realize that you have different modes, just like a triathlete. Right. You go through a test for a triathlete, you do swim test, bike test, run test and come up with different power range, pace range or whatever based on those.

You know, as we're, you know, brainstorming and thinking about this, you know better than me that how many people can hit. A pace that's above threshold walking. Yeah. What gradient. You know. What, what, what percent gradients that you inclined. Well, 44%. Yeah. Yeah. I know most people can hit thresholds on the incline. Walking. Walking. Everybody. Yeah. I mean, even the best people, they're probably at threshold, uh, uh, hiking it, you know, uh, Roger Krom's, uh, former lab. And now it's, uh, Walter Hootgamer, uh, his, his new lab.

Now that they have the steep treadmill, they have a lot of that. They, they have a lot of that data. Okay. Let's wrap it up real quick. Give me one more thing of how you would change the running test. Um, we're going to make it slower. We're going to make it steeper. You want to change the stage length. You want to change the total length of the test. You want to draw lactate at 10 minute intervals instead of four minute intervals. Or is this just such a weird deal? If, if, if we wanted a better lactate test, if that's, that's more of the data that we're examining. Yeah. Is a longer stage protocol. Yeah. So that we see what happens. Cause you know, as the stage goes on, people's lactates could just naturally creep up, up, up, up, up.

Yeah, yeah, yeah. Or they kind of stabilize and maybe even go down. Um, that makes it a worse test to heat, hit the quote peak or max VO2. Um, but a better, if we just want peak VO2, we just want them on a quick and dirty. Eight minutes. Yeah, yeah, yeah. Uh, start kind of hard and ramp right up to the top. Um, you know, I would gather that if we did a similar protocol, keep those stages around four minutes cause they're long enough, but not too long. But take them to max. So it's just one shot deal that that would provide us as valuable information as our stop and go again. Maybe we'll work on this.

I'm going to bring on some former podcast guests and maybe we can bat it around a little bit. Maybe we have a new test two years from now. I'm, I'm thrilled that we had this discussion because I've been meaning to talk to you about it because I, I've known that we need to keep evolving what we're doing. You know, more specific to the athletes that we're seeing and then more, more specific to just the, the parameters that we're looking at now. We have so much more, we're looking at so much more information. We don't have, we have the same amount of information. We just weren't using it before. True. True. Well, I'm right over here. You're right over there. So you have no excuse. All right. We're going to let you get back to your dog into your day. I know you got athletes to work with. Thanks for coming by.

I appreciate it. Welcome. All right, folks. There you have it. There you go. Much thanks to Renee for coming over to my house and recording this podcast in my living room with a dog in the background, trying to distract us the entire time. I've always appreciated Renee's insights and the care that she takes with the athletes that come into our lab. And as I mentioned during the intro, she's somebody that I trust when I have athletes that come into the lab. I know that she is always going to do a fantastic job. So if you are around Colorado Springs, hit us up, go to the train right website. Links will be in the show notes. You are more than welcome. And we would welcome you to come into the lab and get some testing done and see how that can inform some of your training decisions. This podcast pairs very well with the podcast that we released last week with Coach Adam Pulford, all about training intensity.

And next week with one of our new coaches, Frederick Sabatois-Pastor, where we're going to talk about the differences between road athletes and trail athletes with some of his newly released research and what we can glean from that research in order to drive our training decisions. Appreciate the heck out of all the listeners. This podcast is nothing without you. It is brought to you, as always, without sponsors or advertisers of any type so that we can provide you with the most unbiased, unfiltered information possible. So we appreciate the heck out of you. If you like this podcast, please share it with your friends and your training partners. It means a lot to me. And hopefully it brings some wisdom to them that can help them train better. That is it for today, folks. And as always, we will see you out on the trails.

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