Everything You Need to Know About the INSCYD Test

The INSCYD test yields a powerful set of metrics, including VO2max, VLAmax, and an athlete's complete metabolic profile. USA Cycling Level 1 Coach Ryan Kohler explores the INSCYD test protocol and how to analyze its results. See more on INSCYD and INSCYD Advanced Testing.

INSCYD is a physiology test that reveals an athlete’s current fitness and metabolic strengths and weaknesses—in other words, how an athlete’s body burns oxygen and fuel.

The test results can show whether an athlete should be a stronger sprinter or time trialist, a punchy climber, or an all-rounder.

In this Workshop, Coach Ryan Kohler details the INSCYD test protocol and how coaches analyze the results for both outdoor on-road testing and indoor trainer-based methods. He also shares how to prepare for the test, the equipment athletes will need to take the test, and specific instructions for the test session.

The INSCYD test yields a powerful set of metrics, including a complete metabolic profile, all without ever needing to head to a lab (although you can also use lab data). In detail, the test yields the following physiology data:

Metabolic capacity

  • VO2 max: maximum aerobic power
  • VLamax: maximum glycolytic power
  • AT: anaerobic threshold
  • FatMax: maximum fat metabolism
  • CarbMax: carbohydrate metabolism

Load characteristics

  • Metabolic demands & VO2 plotted against power output
  • Lactate accumulation
  • Fat and carbohydrate oxidation for nutrition planning

Metabolic fingerprint

  • Strengths and weaknesses at a glance
  • Ranked against comparison groups

This audio file for the test will walk you through the:

  • 20 minute warm-up
  • 10-second “practice” sprint
  • 20-second sprint
  • 15-minute recovery
  • 3-minute effort
  • 15-minute recovery
  • 6-minute effort
  • 15-minute recovery
  • 20-minute effort

Video Transcript

Ryan Kohler  00:00

Hey everybody, Coach Ryan here from Fast Talk Labs, and we’re gonna have Chris and Trevor here doing the INSCYD test.

Intro  00:22

Welcome to Fast Talk Laboratories, your source for the science of endurance performance.

What’s the INSCYD Test?

Ryan Kohler  00:33

Alright, so we’re ready for the INSCYD test. So, what is the INSCYD test? What do we get out of this? So essentially, it gives you a complete metabolic profile. So, we’re taking not just singular metrics of your performance, but we’re integrating different aspects of your aerobic, your anaerobic, your fueling needs, and putting them together into a complete metabolic profile. So essentially, what we end up with is lab-grade data without the metabolic cart. So, we’ll end up with metabolic results that you can establish a baseline with, and build your training off of those, and then come back and actually retest yourself. So, at the end, we’re going to end up with training zones that will help drive that training process for you. So, with this test, the nice thing is you can do it inside or outside. Today, we’re going to do it INSCYD using the Zwift protocol, so there’s a file for that where it guides you through, but we’re going to take you through and walk through this protocol step by step so that you can execute it yourself with ease.

Preparing for the INSCYD Test

Ryan Kohler  01:33

So, how do we prepare for this test? We know it’s going to be some pretty heavy exercise coming up, but we want to commit to this feeling well rested, well fueled, and motivated. So, no heavy exercise and the 48 hours preceding this, you can still ride your bike, but just don’t go out and do any heavy intervals. So you want to come here feeling like you’re ready to do a hard session. In addition, you want to make sure that you come to this test well fueled by eating a meal or a snack beforehand, so just come here sort of ready to go and ready to put out a good effort, and that means ingesting fuel. So, some carbohydrates are crucial for this, because we’re going to be tapping into that system, and we’ll be asking the body to produce a lot. So don’t come here fasted, come in here with some fuel in the tank.

Equipment Needed

Ryan Kohler  02:16

So, the equipment that you’ll need for this test would include, a heart rate monitor, and a power meter. The power meter is critical, the heart rate monitor we can get by without. Be sure to check the batteries on both devices first, and also be sure to calibrate your power meter. So, one other critical component for this testing is that you want to remain seated for all four tests, so if you’re indoors, this likely won’t be as difficult, but if you do go outdoors, and you end up on a climb, for some of the longer efforts or even the shorter ones, you may have a tendency to want to stand up and get out of the saddle to put out some additional power, we need you to resist that urge as much as possible. So, the reason we remain seated is because we produce power differently seated versus standing. So, be sure to look at the courses that you’ll use if you’re going to do this outdoors, and also check on the grades to make sure that you can actually remain seated on those grades.


Ryan Kohler  03:10

So for your warm-up to get ready for this test, you want to ride for around 15 minutes can be a little bit longer, and you’ll want to also include one or two eight-second surges, so that you can most importantly, check the gear that you’re going to use for the 20-second effort, and just get the legs a little bit more opened up. Finally, after you finish your last eight-second effort, give yourself eight to ten minutes before starting your 20-second effort. So, before you get into that protocol, make sure you have about eight to 10 minutes of nice and easy riding leading into the test.

Ryan Kohler  03:42

Okay, so after you’re warmed up, and you’re ready to go for the 20-second interval, then you’re going to give yourself five minutes of easy pedaling just from any previous surges that you did, we’re going to let everything returned to a baseline level, so you can prepare.

Starting the Test at Zero Power

Ryan Kohler  03:56

The key component before starting this 20-second effort is giving yourself 100 seconds minimally of no pedaling, basically zero power, you want to come into this from almost a standing start, we’re looking for that peak power production from a near standstill. So ideally, if you can coast into the start of a hill or a flat that ends in a hill, that’s going to help you lead into this very nicely. So, if you’re doing this indoors, you’ll have a 20-second block of time where you’ll get a free ride section, and that’s going to be the time where you do your effort. One of the things to keep in mind for this is to go all the way through those 20 seconds, so you start hard, you should reach that peak power roughly three to five seconds, and then you’re going to have a predictable fade at some point after that, but one of the keys is don’t stop pedaling until you reach the end of the 20 seconds.

Ryan Kohler  04:47

If you’re doing this outdoors you want to find a quiet uninterrupted road, with no corners or bends anything like that, ideally a nice straight shot that you can just put out this power for the entire duration. The range is between 18 and 24 seconds, keep 20 in mind, but if you’re a little bit short or a little bit over, that’s okay, it still works.

Resistance Through the 20-Second Effort

Ryan Kohler  05:07

So, having a headwind or a slight uphill to ride into on this test is very helpful for maintaining your power, since we’re maintaining the same gear for the entire 20-second effort, it’s crucial to make sure that you have resistance through the 20 seconds.

Testing Gear

Ryan Kohler  05:22

So be sure to test your gear in a few training sessions before you actually do this, it’s very helpful to save time, because if you find that you’re either over-geared or under-geared and it just wasn’t a good effort, then you’ll have to give yourself about 15 minutes of recovery, which now lengthens your entire test time. So, for efficiency here, go out, you know, the week before two weeks before, do a couple of short 20-second efforts, or even 10-second efforts just to find the gear that you’d like to use for this effort, and you can find the right terrain as well.  So, after you’re done with the 20-second effort, shift down to an easier gear, you’ll take 15 minutes of very easily pedaling in between. If you’re doing this indoors, then you’ll see that the file has your power set to about 50% of your FTP for recovery.

Three-Minute Effort

Ryan Kohler  06:08

Alright, so next, we come to the three-minute effort. This is my opinion, one of the hardest efforts you’re going to put out. It’s going to require a maximal effort for the entire duration. The nice thing with this compared to the 20-second interval is that you can shift gears, and you can come into it from a rolling start. So, very similar setup to the 20 seconds, a headwind is nice, quiet road, no turns or anything like that, relatively flat just so we can maintain a nice consistent power throughout.

Ryan Kohler  06:38

So, if you’re doing a three-minute indoors, again, you’ll see the file has you set to a three-minute freeride interval. If you’re doing this outdoors, you’re going to be doing actually somewhere between two and a half minutes and three minutes and 15 seconds. So that gives you a little bit more flexibility on where you do it and the terrain choices. So, the pacing on this, while the 20 second is just literally an all-out effort, everything you can do, the three minutes should also feel pretty much like this. So, when we get into the longer efforts, there’ll be a little bit more of a build-up to it, this three-minute effort, you want to make sure that you’re putting out power maximally over three minutes. So, this would mean that you don’t sprint out of the gate and then have this huge fall off, we should see a nice increase in the power, and then hopefully maintain. So, give yourself the first 30 seconds or so to kind of settle in, see what that feels like, and think about if you can actually maintain it for the duration. If you find that you have a little bit more to pour on, then definitely increase that well, what we don’t want to see is you know, a rise and a fall and then a peak. We don’t want to see this gradual build either. Ideally, you want to make it look like a nice plateau.

Ryan Kohler  07:44

So you’ll have 15 minutes of recovery, again, after your three-minute effort, if you’re doing the standard version. If you’re doing the pro version, you get five extra minutes for a total of 20, but either way, you’ll have a long recovery in between.

Six-Minute Effort

Ryan Kohler  07:57

So, now we come to the six-minute effort. This should end up really feeling just as hard as the three-minute effort. We’re going to approach this a little bit more conservatively where we don’t want to blow out of the gates and have our peak one-minute power established in the first minute, we want to find a level that we think we can hold for six minutes, and then as we go through keep thinking about, can I pour a little bit more on? If we can, great, let’s add that. So, the first minute to two minutes should really feel like something that you’re not totally stressed yet, right? It’s hard, but it’s manageable is a good way to think about it. As you get to the halfway point, think about if there’s a little bit more you can put on if so apply more power. As you get toward the end of that six-minute interval, you’re going to start to struggle to maintain power. So, keep an eye on the power that you saw early in the interval and make that your goal to try and achieve at least that power, you may see some fall off, but that’s gonna give you a nice target to shoot for. Just like in the three-minute interval, you can shift gears, you want to use a similar type of road, uphill is great for this one if you can remain seated, and again, with all of these remains seated for the entire duration of the interval. So again, if you’re doing this six-minute effort outdoors, the range for this one that will work is between four minutes and up to eight minutes.

Twelve-Minute Effort

Ryan Kohler  09:20

Alright, so finally we have the last effort. This is your twelve Minute. If you’re doing this indoors, you’ll see that free ride is a 10-minute segment, but that falls within the range. If you’re doing this outdoors, you can go between eight minutes and up to 20 minutes, but 12 is kind of a nice target that you can shoot for. Just like in the three in the six-minute, we want to look for a nice uninterrupted stretch of road relatively quiet and something without a lot of bends or turns that will affect your power output, because again, we’re looking for consistency in the power output. Just like we approached the six-minute effort we’re going to approach this long effort in the same way where we start off at a hard but manageable pace, and then as we get about a third of the way through, we check in with ourselves, see if there’s a little bit more, we can add to that. At the halfway point, we’ll recheck hopefully, we have a little bit more we can add power-wise, and we start to turn that on. The last half is where we’re really just holding on, and trying to now maintain that same average power, and if we can push that a little bit great, but again, we want to see a nice plateau, we don’t want to see you know, kind of a peak and a fade, and we don’t want to see this kind of this huge start a fade, and then a huge finish, that’ll affect your results. So, if we can give good hard maximally sustainable efforts for those final three, the three, the six, and the twelve-minute, you’ll get really good data out of this.

INSCYD Test Results

Ryan Kohler  10:39

Okay, well, now we know how to do the test. So, let’s go check in with Trevor and Chris on the bikes, and once they finish up, then we’ll go through the results with them.

Ryan Kohler  11:25

Alright, so Trevor and Chris have finished their testing. Now it’s time to review the results. You guys ready?

Chris Case  11:32

I am ready for the reveal.

Trevor Connor  11:34

Let’s see what we got here.

Ryan Kohler  11:36

Alright, so I’ve got you up on two different tabs. So got yours first, Chris.

Body Composition

Chris Case  11:42

All right.

Ryan Kohler  11:42

All right, here we go. So, we’re gonna go through, and the first part we’ll see is this body composition. We’ve got you at, of course, a very competitive level here. So, this is used to help figure out what the lactate space is how much active muscle mass is being used, and that helps with some of these calculations. So, you know, some people might think the lower the better for this, but not necessarily, but of course, where you are at right around 6%, a very good place to hang out.

Ryan Kohler  12:14

Alright, so, Trevor, you are up here. Same thing. We’ve got your body comp here. We’ve got you right around 9%, so do we start a little scoreboard for ticks for?

Trevor Connor  12:25

Chris got me beat on the body comp right now. I’ll give him that one.

Ryan Kohler  12:31

Yeah. All right, well check out the numbers. So yeah, you can see here, you know, we had Chris at six, you at nine, really both very good numbers, right? These should fluctuate throughout the year, and like you said, this might be a little bit high for you, Trevor, this time of year. But as you get into your season, and you start racing, this will likely come down a little bit and get you into that sort of race readiness. So yeah, we should see fluctuations throughout the season in these numbers.

Chris Case  12:58

What would be too low? Is that opening a can of worms of a conversation we don’t want to have right now or what? Yeah, what’s too low to see there?

What Is a Good Number To Be At?

Ryan Kohler  13:07

Yeah, I mean, I think you’re toward the lower end. Going typically, for men getting below about five is where we start to see some potential issues with, you know, recovery, maybe a little bit more illness kicking in. I mean, I know personally, in my 20s, I competed right around four and a half percent. I noticed I was getting sick a little more frequently, once that started to increase, then everything got better. So yeah, I mean, you’re at the low end. But again, you’ve been doing this for a long time, and you probably hover right around this level normally. If things are going well, then that’s where I look at and say that’s, that’s probably good for you.

Chris Case  13:41


Ryan Kohler  13:41

If you dipped below that, then with athletes that are trying to push below that maybe try to find that racing weight or that more competitive composition level, then always work with them to say, “Okay, let’s see, if you do move that down. One, do it out of competition in a time where you can allow that to happen, and then see how you respond.” You know, it might be something that you can sustain briefly for a training block, or for a race period, and then come back out of it. But that’s the hard part sometimes as we get low, and then we want to just maintain that, and that’s where we run into problems.

Chris Case  14:11

Yeah. We didn’t actually step on a scale or you know, we give an estimate here. So, is that because these numbers aren’t all that crucial for your results?

Ryan Kohler  14:24

Yeah, the numbers won’t affect them that drastically. So, for you, we had you roughly around 6%. If you were four, or eight, or even nine, your numbers would only vary, very, very small, right? If it was between like 6% and 30%, we’d see some more significant differences. But that’s the thing with a lot of us who’ve been doing this for a while we have the experience, we can eyeball it pretty closely. Yeah.

Trevor Connor  14:50

I took a whole-body comp class and at the end of it, we asked the instructor what’s the best technique and he went eyeballs.

Chris Case  14:57

Yeah, self-awareness.

Ryan Kohler  15:00

Yes. Ready for the good stuff now?

Chris Case  15:01


Metabolic Capacity

Ryan Kohler  15:02

All right. So, the first page here we’re going to go through is your metabolic capacities. So this is sort of your, your overview of all those key metabolic parameters that we’ll look at. So we’ll start up here with V̇O₂ max, your maximum aerobic power.

VO₂ Max

Ryan Kohler  15:16

So, you can see for you very, very good, right? You’re 65.1 ml is per kg per minute, in this range, this is showing you around medium, you know, this is actually quite a high number. So don’t, you know, don’t feel bad about this, that it’s that it’s only in medium, but that’s very high. We know that tends to decrease with age, so as we’re all getting older and experienced likely seeing this drop over time, this is a very competitive level to be at.

Chris Case  15:47

Question about the scale. Are they able to put you into a cohort that’s similar to you, like a pro scale versus an amateur scale?

Ryan Kohler  15:57

Yeah. So this one, I actually put you into the amateur scale.

Chris Case  16:00


Ryan Kohler  16:01

So, the pro scale is top-level World Tour Pro. So, if we put you on that, you guys would all be on the very low end.

Chris Case  16:09


Ryan Kohler  16:11

And I would be off the charts if we did that. So, then the amateur, though, is also very competitive. So, the amateur scale is used for high level age group triathlete type of athletes. So, for that one this makes sense. For a lot of folks where 65 ML per kg for V̇O₂ max is not common for the vast majority of athletes. So they would actually be better off in the recreational category, doesn’t sound as great, but it gives you more realistic comparisons within that range

Trevor Connor  16:40

It is still a pretty tight range. So, you wouldn’t have to change your V̇O₂ max much to either drop down to very low or very high. They’re really trying to pinpoint you against a particular group.

Ryan Kohler  16:52

Yeah. Yeah. So that’s really good. So, let’s see. How do you compare to Trevor’s V̇O₂ max? There we go.

Trevor Connor  17:00

Oh, wait, what? Oh, I’m a little chunky right now.

Ryan Kohler  17:04

All right.

Trevor Connor  17:06

So total looks good.

Ryan Kohler  17:07

Total is good, little over four and a half liters there. On the relative side, yeah, 61.6 a little bit lower. So, Chris, you got one for this.

Chris Case  17:17

Now that’s two so far if we’re counting.

Trevor Connor  17:20

Yeah, wait till we get the VLamax, I’m gonna get you there.


Ryan Kohler  17:25

So let’s go to the next one. So VLamax, this is looking at our glycolytic power. So, this is you know, the sprinters are going to be on the high end, the time trialist are going to be toward the lower end. So, for you, Chris, you’re about point .52, in that low to medium range, but compared to Trevor, pretty high, we look at Trevor, and way, way, way down here, 0.3 at the low end, you can see this is a fairly tight range as well.

Trevor Connor  17:50

So they have pro, amateur, recreational. If they had a three-year-old girl on a big wheel, I think I could get medium.

Chris Case  18:02

Yeah, maybe.

Ryan Kohler  18:06

There are some interesting things, though, between what we’re starting to see here, and fat oxidation rates, and things like that. So this is this is pretty cool. This is where some of the differences really start to become apparent.

Trevor Connor  18:16

So, one thing I just want to point out here is this is a physiologist in me talking, but a lot of people ask about V̇O₂ max, it’s important to look at here there is a dot at the bottom and a dot up top. So at the bottom is my absolute volume, so that’s just milliliters per minute, and you notice that’s much higher than my relative which is per kilogram. We can’t do that much to train that absolute, we kind of have what we have. But the quick we know when you hear somebody got a V̇O₂ max of 70 or 80, that’s the per kilogram, that’s the relative. And actually, one of the quickest and easiest ways to change that is to change your weight, so I’m at my like to say I’m at my winter weight right now, but I’m above my winter weight. I have about 10 pounds to drop. So even though that bottom dot isn’t going to change for me at all, the upper dots actually going to move up a fair amount as I drop that weight.

Ryan Kohler  19:20

All right, so we’ve got our VLamax that glycolytic power, so Chris is definitely our sprinter in the group, and Trevor is our time trialist as shown with these numbers.

Anaerobic Threshold

Ryan Kohler  19:30

So now moving on to the anaerobic threshold, lots of different names we can give to this, but this one, in particular, is validated against MLSS, or Maximal Lactate Steady State. So, just to establish that as our basis for anaerobic threshold in this case. So, on Chris here, we see similar to above, with the V̇O₂ max, we see a relative value and then an absolute value. So relative value 4.1 watts per kilogram, and then if we go here to the absolute value 256 watts, and it also is nice here, it gives you this as a percentage of your V̇O₂ max. So, if we’re talking about, you know, raising the floor and getting closer to that ceiling, we now have a starting point to know what, what fraction of V̇O₂ max, are we able to utilize that threshold? So, you know, we were talking about this a little bit earlier, but using MLSS being a little bit lower potentially for folks, right? And I looked at one of your older files from a race, Chris, and we saw that you were actually teeing around 275 to 280. So that was on an uphill time trial as well, but the MLSS, yeah, might be a little bit on the lower side. So, this is likely reflecting what you can do for a very long time, and reflecting that that steady-state and lactate production.

Trevor Connor  20:47

MLSS is a physiological point, most of us have the ability to time trial effort, especially during a 20-30-minute time trial to go at significantly higher wattage and then the MLSS.

Ryan Kohler  20:59

Yeah. So, let’s see, moving over to Trevor’s, we’ve got quite high here on the relative 4.3 watts per kilogram, and then also quite high on the absolute, so 324 watts, or roughly 87% of V̇O₂ max. So, this is still there’s still some room to move that and very strong starting point here. So, I think this is just reflective of your time trial work that you’re doing.

Trevor Connor  21:25

This is my one asset.

Ryan Kohler  21:27


Trevor Connor  21:27

I can just go steady hard. That’s about all I can do.

Ryan Kohler  21:32


Chris Case  21:32

Yeah, and going back to my figure. It’s one of those things where the number is not shockingly high, but my ability to go way over that and come back to that and come way over it and come back to that maybe on a climb out of the saddle, when I’m able to do that because you’re not on the INSCYD test. You don’t see any of that in these figures, but that’s kind of how I would prefer to ride.

Ryan Kohler  21:58

Right. And we can look back and say, “okay, well, you have a fairly high V̇O₂ max relative, we know this glycolytic power is quite high.” So that would support the notion that, yeah, when you do get out of the saddle and go hard, you have the capability to do that. Yeah.

Different Profiles: Climber vs. the Time Trialist

Trevor Connor  22:14

But you’re certainly seeing the profile here of the climber versus a time trialer, which we’ve talked about before. Chris is the climber, and with the research, we’ve read on the different types, climbers will have very high V̇O₂ max, they’ll have a little lower and anaerobic threshold, but as Chris said, they just have that ability to go over the anaerobic threshold. So, you know, I was first surprised by Chris’s wattage, but then realized okay, this is based on MLSS. Chris has got that climber’s ability to go to put out wattage way above what you’re seeing for his anaerobic threshold here, which makes sense. Where I’m the time trialer, so my anaerobic threshold is going to be much closer to my V̇O₂ max, and my ability to go over really isn’t there. So, you’re my anaerobic threshold is actually much closer to what I’m actually what I’d actually time trial at.

Fat Oxidation

Ryan Kohler  23:05

Right. Yeah, and then going with those similarities with your different rider types, when we move on to look at fat oxidation, or this fat max, maximum fat metabolism, we see Chris here that you’re on the lower side, with a relatively low, fat oxidation. But that would speak to your ability to go hard and get out of the saddle and produce power pretty quickly with those through the glycolytic pathways. If we shift over to more of a time trial profile, now we see Trevor being a bit higher here, right? With maximal fat oxidation being a bit higher, even his absolute power, he’s at about 233 watts, where he’s maximally oxidizing that fat. So this is very reflective of that long, sustained, steady type of effort.

Ryan Kohler  23:51

Okay, so we have those two nutrients, we’re working with, fat and carbohydrate. So, we’ve touched on the fat oxidation here, and then at the bottom, the last one to check off is carbohydrate oxidation. So, you can see for you, Chris, you’ve got this lower fat oxidation rate, but your carbohydrate is the dominant fuel in this case. So, shifting over to Trevor,

Chris Case  24:12

So you’re saying I should eat more cookies?

Ryan Kohler  24:14

More cookies. Yeah, yeah.

Chris Case  24:15

Yeah. can do.

Ryan Kohler  24:16


Trevor Connor  24:17

Chris has heard everything he needs to hear we’re done here.

Ryan Kohler  24:20

Cookies are always the solution. Yeah. And then Trevor, we see here, yeah, stronger on the fat oxidation, likely due to the training that you’re doing and your rider profile, and still is, you know, in between low and medium carbohydrate oxidation there. So, you have kind of a good balance between these two, I would say.

Load Characteristics

Ryan Kohler  24:38

Okay, so the next page is your load characteristics, we have four different charts here. So, we’ll go through these and just give you an overview. For everyone, this axis over here at the bottom across the X-axis is power. So that’s consistent across the board, and then we have some different things on the Y-axis going on.

Metabolic Demand and VO₂

Ryan Kohler  24:58

So, this first one looks at your metabolic demand and V̇O₂. So, we have two lines here, and we know as we increase the power, increase the intensity, the metabolic demand continues to increase. So, we see this straight line here, oxygen demand, we know if we keep riding harder, the demand is going to continue increasing. But this is where we get some very good estimates of our oxygen uptake or that V̇O₂, ultimately leading to that V̇O₂ max calculation, and we see at a certain point, as power increases, we start to see a leveling off here. This shaded area where we see this gap develop and then widen with increasing powers is where we start to call in more of the carbohydrate, that glycolytic energy system because we’re unable to meet those needs with just fat oxidation alone, which is occurring down here at these lower intensities. So, if we just look at two, you know, again, the rider profiles, we have Chris here, and we’ll take note of that profile, and then we have Trevor over here, and the one thing if we just switch back and forth a little bit, what I see,

Trevor Connor  26:01

Arrow where mine is.

Ryan Kohler  26:03

Yep, we skip that squish-down profile. So, this is telling us that for Trevor, as the time trialist, he’s able to produce do work essentially, while burning a lot more fat before having to tap into these anaerobic sources. Whereas Chris has that greater ability to tap into that glycolytic system and produce power above threshold very well. So, it’s kind of a nice, easy way to go back and forth and see quickly with those with those differences look like.

Trevor Connor  26:30

Just see our rider type, again.

Ryan Kohler  26:32


Trevor Connor  26:32

You are seeing the time trialer versus the climber, Chris has that ability to attack that I just don’t have.

Lactate Calculations

Ryan Kohler  26:39

Alright, so let’s keep going here and look at some of the lactate calculations. So, moving down here, this is showing there’s a few things going on here, we’ve got lactate production, which is going to be this red line, and then we have this maximal aerobic lactate combustion, which is purple and going across the top, and then this yellow line is lactate concentration right here. So, a lot of stuff to look at, but the take-home with this is one, we want to keep in mind that these values are for steady-state efforts. So, this is suggesting that if you were riding, you know, a steady roughly 200-watt effort that we might see lactate concentrations of around two or so, so not far above baseline. So, this red line is probably the most familiar-looking line for if you guys having done lactate test before, we see that increasing line, that’s what this is modeling. What we see here in the purple line is this maximum aerobic lactate combustion, this speaks to our ability to combust lactate, right? So, we know lactate is not this waste product, end product where it’s just it’s this poison, it’s actually a fuel for the body for the muscles to utilize. So, this maximal aerobic combustion is showing our ability to actually reuse that lactate to transport it out of the cells, recycle it aerobically, and then use that to fuel our exercise. So, there’s a gap in between the purple line and the red line, and that’s really highlighting our ability to recycle that lactate and combust it. So, if we see this crossover point here, this is at that anaerobic threshold. So, this is going to align with that threshold value, and finally, this lactate concentration is just highlighting that once we achieve that threshold point, we see lactate concentration increasing exponentially. That’s just highlighting that beyond this point, we’re no longer at a steady-state, and lactate is just going to continue to accumulate.

Ryan Kohler  28:37

So, let’s kick over to Trevor’s here, and again, we can kind of go back and forth and see some pretty nice changes here. So, this gap here between this maximal aerobic combustion, and the lactate production is wider. So, that really highlights all of the base work that you do the endurance riding that you do, and your sub-threshold work has really trained your body very nicely aerobically. So, that’s where we see this, this crossover point occurring above 300 watts, and that’s going to fall into again, your anaerobic threshold, kicking it up over here to this next curve, we have a lack of pyruvate and lactate accumulation. So, this really highlights your ability to recover from efforts right here. So, this lack of pyruvate is very much in alignment with this gap between lactate production and combustion down here. So, just to quickly highlight again, rider differences, we see Trevor there, and then we kick over to Chris, right?

Ryan Kohler  29:34

So, we see for someone who is good at producing energy above threshold, tapping into that glycolytic system, we see your ability to recover is a little bit different than Trevor’s, who we can just see it’s a bigger, bigger curve, right? So that’s going to speak to a few things but one is just that ability to combust lactate after going hard. So, this is going to be if we look at here, roughly say, you know, in the 230ish range for you, Trevor is going to be the power where you can combust the most lactate. Once we see this line start to fall off, this is very similar to the graph that we just looked at, where now this purple line is lactate accumulation, and this is the point where we cross over that anaerobic threshold, and we’re no longer able to combust lactate, now we’re primarily accumulating lactate. And then for Chris, the same thing we have we have you here, you can figure out and we’ll see these in the training ranges established later, where this will dial into your maximal fat oxidation and give you a range to say, okay, if you’re recovering from an interval, this is your ideal location to recover to combust that lactate. So, then the last graph down here, we’re looking at fat and carbohydrate oxidation or combustion, and I like this one too, just again, to highlight rider differences, we see Chris’s here, and then if we kick over to Trevor’s, we see a huge increase in fat oxidation, right? I think it’s a really cool way to look at this.

Trevor Connor  31:01

What are you saying about me here, Ryan?

Chris Case  31:03

Yeah. He needs to oxidize some fat.

Ryan Kohler  31:04

I’m saying you are oxidizing a lot of fat.

Ryan Kohler  31:10

Right. Oh, boy.

Ryan Kohler  31:14

Yeah, for you, Chris, you have this is good. This is a good ability to oxidize fat, right? But again, your riding style, if you, you know, completely changed it, and started training exclusively with Trevor, yeah, we probably see some good changes here. Maybe you can increase that.

Trevor Connor  31:30

Getting fatter, he has to eat with me too.

Ryan Kohler  31:32


Ryan Kohler  31:35

So, a few things we’ll see here, this green line is the fat oxidation line, and we see that predictably increase and then decrease at that anaerobic threshold, of course, it’s going to go down to that zero point. And then we see carbohydrate oxidation increasing throughout exercise, and ultimately, above threshold, we’re gonna see large increases in that. What this will do is highlight this green shaded area as your fat max zone, so if we’re training to work on that fat max, and increase that, this is that zone that we would want to ride in. This maximum carbohydrate intake, you’ll see horizontally across here, and the yellow shaded line is set between roughly 60 to 90 grams per hour, so that 90 gram being more of that upper limit that we can ingest, and this gives you an idea to see where, what your speed, speed or power depending, if you’re doing a running or a cycling test, where that falls in relation to that usual carbohydrate intake level.

Metabolic Fingerprint

Ryan Kohler  32:30

Okay, so next we’ll move on to the metabolic fingerprint. Let’s get there’s Chris’s data, let’s get yours up, Trevor. We see some differences here. So, for you, Trevor, this is going to show again, here’s our legend, so very low, low, high, and very high working out from the center. So, for your strengths are around this relative V̇O₂ max and fat max, and then of course over here, anaerobic threshold absolute and relative, this is your big strength is that anaerobic threshold, which we know we’ve seen that from the data already. So, let’s compare that to Chris. And we see Chris, a completely different profile here. So V̇O₂ max, VLamax, and relative anaerobic threshold. This is your climber profile, this is the guy that’s going to attack you on the climbs, right? And we see over here, aerobic threshold on an absolute level fat max, he’s not going to be out doing the long-time trial, like we would see with your strengths here and here.

Chris Case  33:30

Good thing I’m doing a 2500-kilometer bike packing race, I’m gonna be attacking every fifteen minutes.

Ryan Kohler  33:36

Just do it as 30/30s.

Chris Case  33:38

The whole time. Okay,

Trevor Connor  33:41

Based on our profile, we really should be swapping events.

Chris Case  33:45


Performance Development

Ryan Kohler  33:46

So, this performance development, we can skim through this one, this is if you do any future tests, we can actually go and look at these different metrics. So aerobic, anaerobic capacity, anaerobic threshold percent of V̇O₂ max at threshold and fat max, so we can just track those changes. So, the nice thing with this is if you go and you identify an area that you’d like to work on, and then you go and train it, we come back and do another INSCYD protocol, and we look at and see are those things changing that we want to change.

Training Zones

Ryan Kohler  34:12

And then finally on to the training zones. So, this is some of that actionable data that you can take and plug into your computer, whatever training platform you’re using, and this one’s a little bit different, where you’ll see a lot of different zones mentioned and they don’t exactly progress in increasing intensity. So, we have our recovery base, and then medio and that’s around our tempo, and then we go back and get into fat Max, then the anaerobic threshold, aerobic maximum, or V̇O₂ max training, high anaerobic, and then we have this other one lactate shuttling. So, it’s a little bit different here thing.

Chris Case  34:48

A linear thing.

Ryan Kohler  34:48


Trevor Connor  34:49

It’s much more in line with what we talk a lot about, which is you need to focus on energy systems. So, here they’re almost literally identifying energy systems and saying, here the wattage range where you will optimally hit that energy system.

Ryan Kohler  35:05

Yeah, so you can, what we see here is for the power for each one, if we go just through the first three and increasing intensity, we’ve got your lower and upper ranges, and then the target watts in there. So, if you’re out and you just need that target, this is a good place to start. But of course, we’ve said this a lot, if you’re doing anything, especially around threshold, that’s where you really need that range. So, you have your targets, but you also have the lower and upper bound to work with. I really like this piece of it, where we get into some of the nutrition, and we look at energy consumptions. So, four different levels here, we can see your expenditure and calories per hour to get a sense for how much am I putting out at a recovery pace, my base effort it’s more of a tempo, and then when we get up here, around threshold, how much am I putting out? So, depending on the type of training you’re doing, or the events that you’re working with, we can start to get an idea for expenditure levels, and that’ll help with then our nutrition planning. And then we see over here, the percentage of fat and the percentage of carbohydrates contributing to our energy production. So, for you, Trevor, we see through your recovery, and your base, you’re very fat dominance, you’re using almost 80% at a recovery pace and still remains very high at your base pace, where fat is the primary fuel for you very little coming from carbohydrates. So, that would mean you could have a different nutrition plan for long rides than maybe, Chris. So, that as we transition into some of these higher intensity levels, in particular, we get into, you know, this tempo range, and then we get right around here at threshold, you can see there are some shifts that occur at tempo, where now carbohydrate becomes the predominant fuel, so of course, that’s going to help drive our nutrition planning for workouts and races. And then of course, once we get above threshold, it’s almost exclusively carbohydrate, basically zero fat, and we can then go over here and say, okay, well, if we know how many grams of fat and grams of carbohydrate that we’re burning at each intensity, now we can start to come up with a nutrition plan, and test something out, and then work with that and try to adjust based on our response.

Ryan Kohler  37:15

So, Chris, same thing for you, we’ve got your target watts down here, and let’s see. So, you’ve got your recovery pace, you’re burning primarily fat, we see that this drops off quite a bit more. So again, highlighting those different rider types, right? Trevor was still around 71% at the base, but we see that you’re going to start relying more heavily on carbohydrates, even at those tempo and subthreshold intensity. So for a rider like you, you might need to focus a little bit more on carbohydrates during those efforts.

Ryan Kohler  37:46

Alright, guys, so we looked at your relative contributions of fat and carbohydrate to the energy production. And for the event you’re doing, which is how many days?

Chris Case  37:56

As many as I want it to be, or as few as I want it to be, but probably seven to ten days.

Ryan Kohler  38:00

Seven to ten days?

Chris Case  38:01


Ryan Kohler  38:01

So, a lot of long, steady riding for you.

Chris Case  38:03

Yeah, those are really big days, 150 miles a day.

Conclusion of the INSCYD Test Results

Ryan Kohler  38:07

Yes. So you’ll be riding probably in this base or medium range most of those days. So, looking at that we can get a sense for your energy expenditure to help with just energy intake, but we also see that at that lower end in the base range, you’re still burning a good amount of fat, could it be better? Sure. But if you do get into that medium range and start running some tempo or sub-threshold, then yeah, carbohydrates take over. So, for training for you, this fat max zone would be a great place to help work on that fat oxidation and spend more time working on getting your body stronger at burning fat, sparing some of those carbohydrates, that’ll also allow you to adjust your nutritional plan a bit. So hopefully, we would see, you know, as you’re going through the training a few months down the road, hopefully, we can see that lack of pyruvate curve and that fat oxidation curve, just get bigger.

Chris Case  38:59

Balloon up.

Ryan Kohler  39:00

Yeah, yeah, exactly.

Ryan Kohler  39:02

And then Trevor, for you, we know you’re the time trialist, you’ve got this great ability to ride long, steady efforts, and your fat oxidation is through the roof. So, you’re doing stage racing or some road racing, so you might have a sprinter to in there, right?

Trevor Connor  39:18

It’s gonna be some effort.

Ryan Kohler  39:19


Trevor Connor  39:19

I think I can see what I need to be working on here.

Ryan Kohler  39:22

Yeah, so for you, I think you’re going to be looking more at this upper end this you know, of course threshold you have this maximum aerobic, this high anaerobic, and your recovery from those efforts as well. So, we’re at this lactate shuttling range might be a great place for you to hang out, and again, we talked earlier about that range, where you can maximally combust that lactate, so this is that lower end of the range. So, for you, the intervals that you might be working on would be well above threshold, and then working on this lactate shuttling piece to improve your ability to recover and repeat and just keep doing that over and over.

Trevor Connor  39:56

The thing that’s a key indicator for me is higher up, looking at that VLamax.

Ryan Kohler  40:02


Trevor Connor  40:03

I’m off the chart low on VLamax, which I’m not going to be sprinting for the finish of these races, I don’t need to be very high, but being that low, if there’s a tax and the races, I’m just not gonna be able to respond. And I’m gonna be spending all day off the back trying to time trial back on, which is not the way you want to spend a race.

Ryan Kohler  40:21


Trevor Connor  40:22

So that’s, that’s what I need to get up.

Ryan Kohler  40:25

Thanks for joining us for the INSCYD test review, hopefully, you learned a lot. If you’d like to sign up for your own test, where we’ll take you through the protocol, and I’ll walk through your results with you, then go over to fasttalklabs.com to sign up. Also, be sure to check out our forum where you can engage in the discussion and put out any questions you might have from today’s session. Thanks again for joining us.