In this episode of The Athletes Compass, Dr. Paul Laursen and the team break down the science and practical application of the second threshold — also known as LT2, VT2, FTP, or critical power. They explain what physiologically happens when you cross this boundary, why base training is essential before adding threshold work, and how over-unders, tempo sessions, and VO2 max intervals raise performance. The conversation explores common mistakes athletes make (especially doing too much intensity), the role of durability, and how to assess threshold progress without lab testing. If you want to train smarter, improve pacing, and sustainably increase performance, this episode delivers a masterclass in intensity control.

Key Takeaways

1. LT1 vs LT2: LT1 (aerobic threshold) = top of Zone 2, sustainable “all-day” effort. LT2 (second threshold) = highest sustainable steady-state effort before rapid fatigue.
2. Above LT2: Glycolytic demand increases, lactate accumulates faster, heart rate drifts, and fatigue accelerates.
3. Functional vs Lab Testing: FTP and critical power are practical field markers of LT2. Lab tests measure physiology, but field tests often matter more for performance.
4. Day-to-Day Variation Is Real: Sleep, fueling, equipment, environment, and training phase can significantly affect test results.
5. Base Training First: A strong aerobic base (mitochondrial development) improves tolerance to threshold work and increases fat oxidation capacity.
6. Over-Unders Work Because: They stimulate mitochondrial adaptations by forcing lactate clearance and improving aerobic durability.
7. Intensity Control Matters: Spending more time in the correct zone is more beneficial than constantly pushing the top end.
8. Most Common Mistake: Too much high-intensity work without sufficient aerobic base.
9. Durability Is the Goal: Threshold training should build resilience so performance doesn’t break down late in races.

• Paul Warloski - Endurance, Strength Training, Yoga
• Marjaana Rakai - Tired Mom Runs - Where fitness meets motherhood.

the base training is going to lift that aerobic threshold, VT1, LT1. It's associated with lots of mitochondrial generation, and it's going to be the thing that we can build on.

And if we don't have that and we just go straight into the lactate threshold it's not really as effective.

Hello and welcome to the Athletes Compass podcast where we navigate training, fitness and health for everyday athletes. Today we're diving deep into the science behind the crucial physiological boundary known by many names, the second threshold, critical power or pace, lactate threshold or FTP, to explore what it really means when your body switches from aerobic to more demanding energy systems.

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We'll cover practical strategies for identifying your personal threshold without lab equipment, proven training methods to raise it, and how this knowledge can transform your race strategy and overall endurance. So first of all, let's get down to the basics. What does second threshold or lactate threshold to, what does that mean in simple terms and how it differs from the first threshold? And I've got my pen ready and my notepad ready, so I'm taking notes.

Yeah, thanks Paul. So, yeah, I'm excited to get into this one today. let's just kind of start first, the difference here between LT1 and LT2 or VT1 and VT2. So lactate threshold one, lactate threshold two, or sometimes we call this the ventilatory threshold one or ventilatory threshold two. And the reason is, is the ventilation system is directly linked to the lactate system.

All right, so in your Athletica Power Profile or PACE Profile, you'll actually see this as the, it's titled AET, basically like your aerobic threshold. So this is the VT1 or the LT1. And you'll actually have a number there. That's a predicted number, and it's similar to what you would get if you went into a laboratory and someone measured progressively how much lactate is being produced.

or is being, it actually appears, could be from an earlobe prick or a finger prick. ⁓ But basically we all of a sudden see at that LT1, we see a substantial rise in that blood lactate level. And it's coupled with an increase in ventilation. All of a sudden the respiratory buffering system starts to breathe higher as well, right? So you can pick it up in either or. And then of course we pick it up using AI.

⁓ as a likely predictor of where that sits just from your training data. Okay, now let's move into the second threshold. You will also see this in your Athletica profile. It is in orange, and we just title it threshold, but if you hover over it, it's actually your critical power or your critical pace. And again, this is just a predictor, this is like a functional predictor of the physiology that is going on.

⁓ within you and going back to that LT2, this ⁓ is the highest intensity where lactate is stable and above that, fatigue rises quickly. Now let's also put a, let's connect our mind to how that feels. The LT1 is sort of your all-day steady aerobic work. It's the top.

of your zone two, right? We talk about zone two training. Let's write at the borderline of where zone two training goes into your no man's land, your zone three sort of world where you would compete at like a half Ironman or an Ironman. That's the zone three. Now zone four or this LT2,

That's what you would race a 40K time trial at, for example. If you're on the bike, you'd probably be right around that. Anywhere from 20 to 40K of all out, that's sort of your LT2 area. And in the running context, think about something like a 10K race. You'd be running that right around your LT2 as well. So yeah, it's relevant, sustainable intensity.

And that's a really good place to mark zones in Athletica. So they're very practical for us in terms of being able to prescribe exercise intensities that kind of hover around this physiological landmark.

So what happens physiologically when an athlete crosses that second threshold?

Yeah, so at that point, great question, the exercise intensity and the energy needed for that to achieve that functional intensity, it's all of a sudden at a point where you have to use a whole lot more of the glycolytic energy system. All right, so you've got your aerobic system where it's really using a mix of fat and carbohydrates burning in the mitochondria.

and the mitochondria of the cells are the powerhouses. But then there's also energy that's produced in what's called the cytosol of the cell, so the cell space, and that's like an extra energy reserve where there's enzymes that can function to burn more energy and they use carbohydrates. And all of a sudden the byproduct of that carbohydrate oxidation is lactate.

And it's a great system that we can always leverage whenever we have to run away from a tiger or burn sugar a little bit faster. And that's all of a sudden going outside of that, like that higher glycolytic flux it's called and larger fast twitch or fiber two recruitment causes that like more lactate to be produced.

which is associated with fatigue. It's not necessarily the cause of it, but everything's sort of happening in this. So yeah, there's other things that happen too. There's this rapid increase in ventilation that happens. There's an increased perceived effort. And then also you'll see heart rate is no longer stable. It's drifting upwards. Your body's really working hard at this point.

to kind of compensate. But there is this, it's like the last available steady state period before going into overdrive.

So how is, you know, we talked about a lot of different names. You how is LT2 different than VT2 different than FTP functional threshold power or critical power or pace? Or are they all kind of talking about the same thing?

Yes, so they are all trying to estimate the same thing, but the difference is is that the LT2, lactate threshold two, or the ventilatory threshold two, you're measuring with ventilation, those are physiological break points, but

the whether it be FTP or critical power, these are functional observations that are occurring at this, right? So remember that FTP is 20 minutes all out, the greatest power or pace that you can go at that for that duration. And then, take 5 % ultimately for FTP, critical power would be similar. And these tend to correspond, but

but not always, but tend to correspond with the physiological breakaway points. So when you're looking at your athletic charts, we obviously, you're not doing a physiological assessment at this point. So you're just getting the functional marker, but that's still very, very useful. And from a practical standpoint, it's not that there isn't value going to laboratories, but you look at the price point and paying,

know, $200 to $400 to go into a laboratory to get this assessed. It's a little bit more economically feasible to do a couple functional tests and get a pretty close marker as well.

often or sometimes get a question. Why are we not or somebody has done lab tests and then they come to atheletica and our estimation is not corresponding. It might be off a little bit or sometimes a lot and they wonder why.

where's the difference coming from? So that's their answer.

That's the answer for sure. And you know, remember that you're always welcome to change those manually. And now on the new user interface, you just go to your sport profile and pick the profile that is meaningful to you.

You've got your options from cycling, running, swimming, and rowing. And then you have, if you go below the chart, like the functional profile chart, if you look below that, you'll find your training zones and you'll have your threshold power that's there. So that is what we're talking about here today. That is ⁓ your second threshold power or pace, and you can manually change that there to the level that you want. And in both the heart rate,

and the power or pace. So it's fully customizable. That's where you insert it and your zone should update accordingly.

So Paul, you've seen a lot of physiological tests and like how much can, because sometimes I'm a little puzzled when people complain about five watts difference. And we tend to forget like when you go to a lab, it's not like, it's not, it's just the

one point in time that you do that test and comparing, for example, power measurement on a bike that is in the, on on the lab setting. Maybe it's not even your own bike. Maybe it is, but how much can day to day variation play in the role here? Like, what are we talking about? Like can one person perform like

10, 15 watch better one day compared to like week later or whatnot. Let's say the same test, 20 minute all out, like regular FTP test. How much have you seen in your top athletes? How

Yeah, so.

much of a difference?

Well, the answer is honestly it depends because if you're not if you're just starting back training say for example we're in the winter offseason right now and when you go back in the very first test that you do you might be not as not as top as as you were back in the in the peak of last season and at that point in the game the changes are quite quite quick and you do you would see

10 or 15 watt changes within a week potentially if the training is regular, right? If you're all of a sudden laying down base and laying down a few high intensity sessions. The changes are quite rapid to a point. So in that context, they can be quite rapid. Back to the other point that you made about the comparison of the laboratory test where you might actually do that on a different bike. you'd go into a laboratory, they're often equipped with loady cycle ergometers.

or others, who knows what that power output is relative to the power meter that you might use. A lot of laboratories now are actually using ergometers that can use your own bike, which is great. And then I think we have a, that's improving sort of the validity of the marker. But again, you are, we're always comparing these physiological occurrences, right? And this would be VT1 or LT1 that I mentioned before.

and LT2 and VT2 ⁓ and then you're comparing those with the functional markers as well. My bias based on the athletes that I coach is that the functional stuff matters. Like this is the functional stuff, what you do on your power meter out in the field, that's what, that's gonna be relating to performance. Because you're out in the field and that is performance, right? So that's why

I prefer doing these on your own bike with your own power meter and your own heart rate monitor and and ideally on a on the same hill so many my athletes we'd always have the you know, we declare what the hill is this is gonna be your test hill and This is where you're doing like your repeated performance tests and That's that's my personal preference. So

You could because then you've you've got the same power meter You've got the same hill and yes, the environment may change a little bit wind rain heat all these sorts of things but more or less they're Same with race exactly right there more Yeah, they're there. They tend to be not too bad. So ⁓ Yeah, I don't know if I answered your question MJ, but that's I've kind of Poked or poked around a few a few issues there

But so does a race day too. You don't know what you get.

Yeah.

Yeah, so basically there can be a lot of variation between, test week results. can be difference between the lab and the real world setting based on how it's executed.

Absolutely, yeah, it can be really large. Especially if the power meter isn't the same and the bike isn't the same as your bike. So that's a big one. you can wipe that one out and you're using your own bike with your own power meter, boom, now we're talking.

Yeah,

And then, yeah, but then again, everything that you're measuring in that laboratory, they are internal physiological markers of occurrences that are happening in that instance. don't necessarily, they're not necessarily gonna happen next week if you test them again. Maybe they will, but maybe they won't. But.

Hmm.

and.

And how you sleep and eat can affect those as well. So.

Mm-hmm.

Yeah, all these different things, right? So this is, again, this is my bias, but this is where the system like Athletica really shines because it's one of the key things that we always look for in science, and specifically laboratory tests, is the process of reliability and its repeatability.

It's the ability to kind of do your tasks time and time again. And when you were doing that in Athletica and when you're getting that marker day in and day out, you're seeing what that reliable marker is. And that could be, even the way we do heart rate variability overnight, it's time and time again, night after night. It's in the same sort of process, right? And it's...

Garmin's going through the same process and it's finding the lowest marker of HIV through the night as you sleep. Boom, that's the marker. We always do that same thing every night. And it's the same with your training, using the same power meter, using the same heart rate monitor, hopefully. And there's subtle changes and stuff. again, there's, repeatability of those,

items or those variables are so close together versus the laboratory marker where you're getting this snapshot of randomness where if from one week to another week and who knows how much difference could be could be in there or month you know the next month or whatever and again yeah so

So

what's the value of doing a lab test then?

Well, it's a good question. think first of all understanding. ⁓ One of the big ones for lab tests is substrate oxidation because if we do a metabolic test and you're wearing the VO2 equipment, you're measuring output of carbon dioxide and intake of oxygen and you can use some equations to get some insight into how much

carbohydrate versus fat that you're burning. And one of the key problems that we see often are athletes that don't have a really good solid base behind them and they lack the ability to burn fat as a fuel. And if you're right off the get-go having to burn carbohydrate, glucose, don't really have, you're not be able to kind of access that nice base of fat stores, which is the all-day energy source back to the

LT1 definition that I started with or the in an Athletica AET aerobic threshold. You're not able to even get that. if that's suspected by the coach, the coach can order a metabolic test to confirm that. And you really can only get that confirmation of that if you're actually measuring that with gases. that's where it's to me, that's where it's mostly useful.

what types of workouts, if we're taking this idea of thresholds, what kind of workouts are going to be most effective for raising that second threshold? Because I assuming, I mean, this is an obvious statement, we want that to increase.

We do. We do. I mean, it's the same concept as FTP or CP, critical power. Right? So you, of course, there's a strong association, but not absolute, but a strong association between that and your performance, how much power you can, or pace you can produce. So yeah, you do want to improve that. And probably like,

Mm-hmm.

No surprise, the principle specificity holds true. So if we do periods of time at that power or pace, broken up, these are usually called moderate intensity training efforts because they would be at or just below, they could also be just above too. like an over-under would be a classic session where we would do that too, right? So over-under in the word, you're over and under that.

⁓ that marker, right? So you're doing a little bit of time, maybe one minute above, just above, maybe in zone five, and then below that, you're, know, in theory you're kind of recovering, maybe that you're in zone 3A, but man, you've already pushed out this big push of glycolytic energy and O2 debt ultimately, and even though you're at...

zone 3A, you're recovering but not really enough, right? And it really stings for the rest of that zone 3A portion. So that's a great segment to do that. Yeah.

Yeah, those over-unders, you know when you first start doing them like in the beginning of build, they feel totally different than at the end of the build. Like, you know when you're ready to perform long distance event when

Mm-hmm.

those start to feel much doable and you can repeat the efforts.

Yeah.

Yeah. And let's just think about what's happening there, right? So I gave everyone a background of what's going on. So we've got these two areas in the muscle cells, the cytosol, or the space in the cell, where this is where the glycolysis takes place and the lactate gets produced.

And then you've got the energy production part of the cell, the mitochondria. And in over situation, you've maxed out that glycolytic sort of situation. And then you've moved into the mitochondrial sort of space in the recovery area. And the mitochondria has got to do all this work to quench all the lactate that's been produced. And then the next time you do that, well, let's go and recover now.

there's in the recovery process, you've signaled for more mitochondria to be produced because the cells do not like that. And their job now is to produce more mitochondria. So just like you said, MJ, you said, I hate it when I do that for the very first time, but ⁓ next time I go and do that next week, it's all of a sudden not quite as bad. And then a week after that again, not quite as bad again.

And that's because you've created the, you you've driven the adaptation process and your fast twitch muscle fibers have created more of the mitochondria and they are there now to, make this, ⁓ you're more durable. ⁓ You've ultimately, you've probably done everything you need now to lift that second threshold, which was the whole purpose of these.

because now you can do all of this high intensity more aerobically and you don't need to rely on the glycolytic ⁓ aspect of this anymore. And that's the whole purpose of why you do that type of training.

So how do intervals at threshold or just below, you know, differ from those that are just above? I mean, just above things are gonna start breaking down at that point.

Yeah, I mean, this is where, Paul, there's more than one way to skin a cat. You can go about this many different ways. This is where long intervals, VO2 max work, short interval VO2 max works, over-unders work, just specific threshold training works. It's all kind of doing the same sort of thing. And this is where you can, if you're bored of the same one or you want to see if you adapt a different way, it's a great

great to be able to leverage the workout wizard and flip that around and do a little bit of a different session if you know the principles that we're teaching right here, right? So yeah, there's not a ⁓ one size fits all, ⁓ but there's, and this is why it's good to kind of work around that threshold to do some of your work above it and then definitely lots of work below it.

One thing we haven't mentioned that's so critical, this is where the importance of a good period of base training is so important to improve your tolerability to this, right? Because the base training is going to lift that aerobic threshold, VT1, LT1. ⁓ It's associated with lots of mitochondrial generation, and it's going to be the thing that we can build on.

We know adaptation energy now is ultimately speaking about the ability to burn fat as a fuel back to the base. Probably just workouts that are consistently too hard. So there's a lot of...

What's the biggest mistake that you see people do with trying to increase their threshold? Okay.

Yeah, there's a lot of advice out there that you just got to train hard all the time, right? And you can do that. No question, you can do that. ⁓

But it's not as sustainable. And you've got to have that base around it. This is what we know works so much better. If you have the base, if you're building that high intensity training on top of the base, awesome, you're going to have success.

If you are just going straight in from day dot one and we're doing high intensity work all the time without, know, straight into build training without a solid base, you may break down may be just, yeah, you're running yourself into the ground a little bit.

When you say too hard, are you thinking too much high intensity training or threshold intervals too hard, like too high intensity or too many?

All of the above. All those different ways

Yeah. Yeah.

to get too much high intensity work in your system without the buffering of the aerobic part around it. Remember the Norwegian model ultimately, and this is from Øyvind Sandbakk great

interview and recent paper of 12 of Norway's top coaches that were most decorated. There were over 350 medal level athletes. remember that in their review, they found that all these programs had that aerobic base. So was traditional periodization. So they had the aerobic base. They had the adaptation energy.

And then they had just three quality sessions in that week. And those sessions that were quality were all of the stuff that we were sort of talking about here already ⁓ in those different ways, whether it's VO2 max, over-unders, threshold works, short intervals, all those different ways to skin the cat depending on what you're feeling, but just three quality ones in that week. And that tended to be the recipe for the success.

Sure.

So I know some people when they're looking at zone four training, like intervals, they're always aiming at the top of the zone four. So ⁓ it's okay to go a little bit under actually. Don't always have to

aim at the top of the zone.

For sure, especially if you know the set is going to be long, right? That's really when, and we learned that when we're doing your velocity sessions, MJ, and I love how you coach them and you are always keeping an eye on everyone's intensity and you're reminding us to don't, you know, hold a little bit back. We've still got some to go here. You call people out in the session and you're saying, I see you're doing really well. You're at the top of that zone.

And.

Mm-hmm.

Remember, you you're still gonna be at the top of that zone later on, right? And it's a great reminder. And you're absolutely right. Like you just want, you wanna be in there. You wanna continue to give your muscles that signal to be able to adapt. And you do that by, this is the Norwegian method wording. They call it intensity control. ⁓ you know, MJ.

you you

to spending so much time in that Norway program. know you know all about intensity control and that's what you're trying to teach us, which is awesome.

Mm-hmm.

I know ⁓ Dr. Seiler always talks about accumulating time in the zone and whatever zone that might be that you're working on with the threshold. going too hard is going to prevent you from accumulating that time because you just can't manage the whole time. How do athletes know that they're working at or right at their second threshold? What kind of signs they have?

Well, yeah, that's a I think there's always three key ones that we can all use. Most of us have the key tools. Most of us have a power meter or a GPS monitor. So we're getting some indication of the pace or the power that we're going at relative to our zones. We also have a heart rate. And if there's a prolonged period of time, then it will reach that plateau.

And so that's another marker where you, you if you've gone long enough, you'll, you'll actually get into that zone too. But probably the number one is the, is the feel you want to develop your feel for, for that, that zone for as well. And it feels hard, like it feels hard and you're, you're just below the unsustainable part, but, but you're like, you're kind of thinking about it you're like, no, if I was doing 40 K T T.

you you

This is what I'd be holding it. This is what I'd be holding at kind of thing. and the more you do these things, the more you get a hold on it. So, and if you haven't

Mm-hmm.

got that yet, that's okay. Just be patient. Learn from your last session. ⁓ You know when you haven't got this right because you fade and your power just goes, right? Because you're, ⁓ and I'm still learning this. But like.

What do you mean? You're so

good at pacing yourself.

you

Yeah, but I still still blow it sometimes as well, you know, it's a yeah, but it's like Yeah, it's it's a it's a learnt it's a learnt skill is in terms of intensity control and I've Been training a while and I'm still learning it

You

Mm-hmm.

Yeah.

You mentioned something about long enough, when it comes to heart rate. Let's talk about assessing your effort by heart rate on these zone four intervals. Thank

Sure,

Well, your heart rate can hold that zone for like, so for example, if you're gonna, this is, think of you doing a race. If you've ever looked back at a race trace, you know, whether it's a 10K run or a 40K TT on the bike, like you'll see it, it'll just, you know, after five minutes, it will go up there and it will just kind of.

hold and usually if you're conditioned it will lock in at that heart rate. And of course it usually drifts a little bit more, drifts a little bit more until it's at the max. You'll see this if you do a 5k TT run as well, which is kind of the calibration test for our runners. And you can see that even that last 10 minutes is where it goes out. it's, yeah, it's.

It will lock in at that. It's the last sustainable point of sustainable pace or power. And you can definitely hold that for five or ten minutes. And that's a great marker of knowing that you're in the zone. Of course, it will usually get higher and higher and higher, like just a little bit higher and If the pace or power is the same, you may have to...

Mm-hmm.

decrease the power or pace if you want to maintain that heart rate ⁓ zone throughout as well. And there's no right or wrong way to do that. The key thing is to try to accumulate time in that zone ⁓ because like we said before, you're going to get better following a recovery period. Don't kill yourself. Always leave. You could do a little bit at the very end.

Don't absolutely smash yourself or the next session is the most important session. But yeah, like you want to, and then also look back at time and zone. So look at your session analysis, look at what the goal of the session was in terms of time and zone and see what you achieved relative to that. I always love doing that, especially when I'm in the coaching process as well.

Looking at what my athletes, what their time and zone was, and then giving them some advice accordingly. That time and zone recommendation is there for a purpose.

But it will take a little bit of a time for the heart rate to catch up, right? Because this lag time, yeah.

yeah, there's a lag time, no question. Yeah, yeah, like I said before, if you were gonna do this, like just a time trial,

Yeah.

you'll always notice that it takes five minutes to get up to steady state. And then it plateaus and then just drifts slowly.

So it's better to do the intervals, like say you have three, four minute intervals, it's better to do that by pace or power instead of trying to get your heart rate to go up to the target.

Yeah.

That's a really good point. And so for zone four and higher, yeah, go by pace or power. For zone three or lower, go for the heart rate. And usually there'll be longer ones as well. So I'm coaching a runner right now, and we're having this exact conversation. So we're in the base period, and we're focusing mostly on zone two training or below.

So a very heart rate clamped kind of work. But we also are doing one tempo session a week. And in that tempo session, that's where I'm looking at the heart rate. Because the, yeah, so sometimes the first one might be in it, but then the heart rate drifts in the second one. So now we're, I'm asking the athlete to clamp that, actually bring the power or the pace that she's running down so that the heart rate is still clamped at that.

Thank

And again, we're trying to, back to the intensity control. I don't want excessive stress in the athlete's diet, training diet. And again, this goes back to where you asked about what's the most common problem that I see in training programs across the world, and it's just too much high intensity. So there's a time and place. yeah, the intensity balance, easy and hard, that's the key thing that advances us.

Mm-hmm.

Yeah.

Yeah, so last week she put her

So your aim with the runner is that she coming off a base or you are in a base now after a few weeks or a few months of doing one tempo session that she can hold that tempo pace with that without a drift of heart rate to zone four or upper zone threes. Am I correct?

her pace was too high and her heart rate drifted up into zone four. So this week I'm asking her to go to drop the treadmill speed down, we're in the winter here, but drop the treadmill speed down and just hold that heart rate. That's what I'm asking for. And my prediction, if we're adapting right, is that pace will get higher and higher at the same heart rate, but the heart rate will of hold in those zones.

Mm-hmm. Mm-hmm.

Mm-hmm.

And back to the key adaptations that we're asking for in all of these, her body should make more mitochondria to drive the whole process more aerobically and less cytosolic blood lactate will be produced. this is a positive that ultimately her training becomes less stressful for her as she goes. But if we're always hitting that too hard, we don't adapt.

That's not the fastest road to Rome.

So that's a good way to teach the intensity control mentally on a treadmill, because you're so locked into one speed or pace. ⁓ And when you're running free, it's much harder to control your speed, right? Because you just kind of drift, you start feeling good, you start feeling all the energy, lactate, you're like, yeah, I'm running.

Mm-hmm.

I'm moving, but yeah, that's a really good way to teach that. Ultimately, it is self-control.

Ha ha ha.

It is, it is. Well, actually with most of my Ironman champions that I've been blessed to be able to coach, that's, I've almost done like 50-50 treadmill and outdoor running. And because you can just control so well the intensity of the treadmill for like for key sets and ⁓ these and tempo sets, whatever.

Mm-hmm.

Mm-hmm.

Your answer a minute ago was a good segue to the question about how do you know the threshold training is actually working without more field testing.

Well, this is the beauty of invisible monitoring to me, Paul. And it's just the fact that, you know, the, should, again, if it's, if everything's working and the athletes healthy, we should see, next week we should see faster speeds, even slightly, you know, as Luke Evans told us on the podcast, like everything is just, the improvements are just so slow. if the, the, name of the game,

Yeah.

in this endurance training world is patience. But if we're patient next week, we should see a small bump in that running speed relative to that heart rate. And if the athlete does what I asked her to do, she should control that intensity and the heart rate should not drift up into zone four like it did this week. So that will be sort of success. But again, everything will just keep drifting up.

And that whole, if we look at that power and pace profile that's in that nice blog that's written by Andrea Zignoli where we're actually looking at how Athletica uses invisible monitoring to capture the power and pace chart that you'll see ⁓ in your Athletica sport profiles, the left-hand panel. And you'll have a look at all of the cycling power profiles, the running pace profiles, et cetera, et cetera.

All right, anything else you want to add to this discussion of threshold, Paul?

I think a lot of it, you know, it's kind of coming down to this topic of durability that Harrison Dudley-Road, who's working with us now, he wrote a great blog for us on this. We're trying to actually look at that concept of durability. And when we're looking at durability, it's like the word suggests, right? You're durable, you're not breaking down.

Thank ⁓

And I think when you're doing some of this training that we talked about, over-unders, short intervals, long intervals, base zone two training, it's all working towards being more durable. That is really what ⁓ we should be looking at with that, the second threshold. The second threshold really should be an awesome indicator.

getting towards that indicator of durability. And of course there's other things too, there's other factors. But as our technology improves, we wanna be really be looking at how well that heart rate holds to sustain any of those paces or powers. we're working in the back on the ability to create a durability index.

Hmm.

That's really, I think, that's the dream where we would like this to go in the next year or two. And as we look at it, that's what all the training should be going to produce, a more durable individual, with that heightened second threshold.

Wow, that would be cool because that would give us a really great measure of how things are working.

It would it would yeah, and especially when if we can relate that back to the athletes performance because that's what they care about so that's Yeah, that's that's a work in progress Stay tuned

Stay tuned.

Yeah. Well, thank you for listening today to the Athletes Compass podcast. Take a moment now, subscribe, share, and let's keep navigating this endurance adventure together. Improve your training with the science-based training platform, Athletica, and join the conversation at the Athletica Forum. For Marjaana Rakai and Dr. Paul Laursen I'm Paul Warloski, and this has been the Athletes Compass podcast. Thank you so much for listening