High Intensity Training, with Dr. Stephen Seiler

In episode 75, we’re joined by one of our favorite guests, Dr. Stephen Seiler, who is one of the top exercise physiologists working today. Dr. Seiler has talked with us previously about the polarized, or 80/20, model of endurance training, he’s shared his thoughts on zone models, and he’s helped us understand how slow your “slow” should be. For more with Dr. Seiler, return to episodes 51 and 54.

You’ve sent us more questions about those two episodes than any other episodes we’ve done, but the most common question has been “when’s part 3?” Well, this is that episode. We’ve already talked about the overall polarized approach and how to do that 80 percent — the long, slow ride. Today, we’re going to talk about the other 20 percent: high intensity work. In this episode we’ll address:

Why, even though Dr. Seiler recommends 80 percent or more of our work to be at low intensity, he is by no means against some hard work. After all, he did put himself through a one-hour FTP test for our last show.
What you should use to structure the intensity of your interval work: heart rate or power, percent of max or percent of threshold. Or, is there another approach? His answer might surprise you.
Dr. Seiler’s multiple studies on interval work, including the three protocols he’s studied — 4×4 minutes, 4×8 minutes, and 4×16 minutes.
Notice that while each workout is hard, none of those three protocols is very complex. We talk about why things like execution, accumulating time, and consistency are more important than complexity.
Some of you may cringe, but we also discuss why the specificity of interval work isn’t as important as a lot of people think. To a degree, most work hits most systems. So don’t get caught up in being a few beats or watts over or under the target.
We’ll briefly discuss the periodization of interval work.
We’ll wrap up the show with a discussion of higher intensity anaerobic intervals such as Tabata’s, and ask both Dr. Seiler and some pros about their favorite interval work.
Finally, we’ll answer the pressing question: Who’s the biggest nerd of all.

Our primary guest today is, of course, Dr. Stephen Seiler. At this point, he needs no introduction. He is one of the most influential researchers working today. Along with Dr. Seiler, we’ll hear from Michelton-Scott rider Brent Bookwalter about balance in interval work. This is the third episode in a row that we’ve heard from Brent, and that’s because as a top pro, who’s raced 10 grand tours, he has a lot of good things to say.

Next we’ll hear from Ruth Winder, a talented racer on the women’s Trek-Segafredo team. Finally, we’ll hear from Bruce Bird. Bruce took up cycling in his 40s and has since won the Gran Fondo World Championships multiple times. At 50, he can tear apart the local pro races in Ontario. In other words, he’s figured out a few things about proper training. So, if you’re ready to get intense, if you’re prepared for a smattering of nerd bombs, it’s time to make you fast!

Primary Guests Dr. Stephen Seiler: One of the top physiologists in the world
Secondary Guests Brent Bookwalter: Pro cyclist with Mitchelton-Scott Ruth Winder: U.S. national road race champion with Trek-Segafredo

Episode Transcript

00:00

Welcome to Fast Talk, develop news podcast and everything you need to know to ride like a pro.

Chris Case 00:15

Hello and welcome to Fast Talk. I’m your host Chris case managing editor of velonews. I have returned from my worldly travels, finally. Yes, I had an amazing time on the Isle of Skye at wild horse gravel in Grand Junction. And at Oak route, Asheville. Yes, I now need a vacation from all of my travels. That time will come until then, there’s Fast Talk. I’m joined today by a former Chris case impersonator Coach Trevor Connor, who did a fabulous job keeping you all entertained while I was gone. Thank you, Trevor. I particularly pleased to return with this episode as we’re joined by one of our favorite guests, someone who has also proven to be extremely popular with our listeners. Dr. Steven Siler is one of the top exercise physiologist of today, and Among his many credentials as served on the executive board of directors for the European College of Sports Science. Dr. Seiler has talked with us previously about the polarized or at 20 model of endurance training. He shared his thoughts on zone models. These helped us understand how slow you’re slow should be. For more with Dr. Seiler returned to Episode 51 and 54. You are faithful listeners have sent us more questions about those two episodes than any other episodes we’ve done. But the most common question has been, when is Episode Three with Dr. Siler. Well, this is an episode, we’ve already talked about the overall polarized approach and how to do that 80% the long, slow ride. Today we’re going to talk about the other 20% high intensity work. In this episode, we’ll address first why, even though Dr. silo recommends 80% or more of our work to be at low intensity, he is by no means against some hard work. After all, he did put himself through a one hour FTP test for our last show. Secondly, what you should use to structure the intensity of your interval work heart rate or power percent of Max or percent of threshold, or is there another approach? His answer might surprise you? Number three, Dr. siloes. Multiple studies on interval work, including the three protocols, he studied four by four minutes, four by eight minutes, and the dreaded four by 16 minutes. For notice that while each workout is hard, none of those three protocols is very complex. We talk about why things like execution, accumulating time and consistency are more important than complexity. Number five, some of you may cringe but we also discuss why the specificity of interval work isn’t as important as a lot of people think, to a degree, most work hits most systems. So don’t get caught up in being a few beats or a few watts over or under the target. Number six, we’ll briefly discuss the periodization of interval work. Number seven, we’ll wrap up the show with a discussion of higher intensity, anaerobic intervals such as devadas, and asked both dr Siler and some of our favorite pros about their favorite interval work. Finally, we’ll answer the pressing question, who’s the biggest nerd of the mob? Our primary guest today is of course, Dr. Steven Siler, the Jay Z of physiology, as Trevor likes to call him. At this point, he needs no introduction. He is one of the most influential researchers working today. We thank him for joining us. And for all the time he spent answering our listeners questions on Twitter, along with Dr. Siler. We’ll hear from mitchelton Scott writer Brent bookwalter, about balance in interval work. This is the third episode in a row that we’ve heard from Brent, and that’s because as a top row, who’s raised 10 grand tours, he has a lot of good things to say. Next, we’ll hear from Ruth Linder, a talented racer on the women’s trek segafredo team. Finally, we’ll hear from Bruce bird, Bruce took up cycling in his 40s and has since won the granfondo World Championships in his age category multiple times. At 50. He can tear apart the local pro races in Ontario. In other words, he’s figured out a few things about proper training. A quick note toward the end of our interview with Dr. Seiler, our recording system went to put so we had to finish the recording on a smartphone forgive the sudden drop in audio quality. So if you’re ready to get intense if you’re prepared for a smattering of nerd bombs, it’s time to make fast.

Trevor Connor 04:39

This episode of Fast Talk is sponsored by whoop. This was one of the really interesting things I remember learning about many years ago and one of my physiology classes. I wish I could find the details about this. But one of the things that made German cyclists back in the 80s absolutely dominant was apparently they had the athletes living with a team of doctors Some physiologist and quite literally, they would get up in the morning and go down and get a whole evaluation. And then they would be told, here’s what you are able to do today. So it’s just an assessment of how recovered they are, how beat up they are. So they didn’t just have a standard training plan that they had to follow no matter what it was really customized to where they’re at every day. And that gave them an edge. And what’s really neat now is essentially, with a product like whoop, you kind of have that on your wrist. You’re going to get up in the morning, it’s going to give you an idea of how recovered you are, how good your sleep was. That’s going to allow you to adjust your training.

05:37

Yeah, it’s pretty fascinating to think about all of the technology that has been reduced and slapped onto your wrist and gives you that feedback immediately daily, and customized to you as as an athlete as an individual.

Trevor Connor 05:52

This is why I was born 20 years too early. When I when I was in my 20s I love music, I’d have to carry around these giant things of CDs everywhere that I went, I was filling up my car. Now I can fit it all on my phone. Same thing back then you would have had to have a bunch of physiologist in the back of your car. Now you can just carry it on your wrist.

06:08

Exactly. We’ve come a long way Trevor, we have

Trevor Connor 06:11

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Trevor Connor 07:31

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10:24

Well, today we’re joined by Dr. Steven Siler, who is sitting in Norway in a beautiful spring day in Norway. We’re sitting here Trevor and I in Boulder on a beautiful spring day. So in the closet in a closet.

Chris Case 10:39

Dr. Seiler, really, you don’t need any introduction. But we have noticed your episodes about polarized training, the polarized approach have been extremely popular with our listeners. So, so much so that we’ve received how many letters Trevor 8000. So I put

Trevor Connor 10:57

it in our notes for the conversation today, if we have time, answer some questions. And last night, I started collecting the emails of questions and went, Oh, wow. That’s like two episodes, just answering the questions. We’ve gotten a lot of really great questions. And we do appreciate all the interest.

11:15

Yeah, we’ve really discussed polarization, we’ve discussed the 8020 concept or distribution within the polarized model. One thing we haven’t really discussed in depth yet is that 20%, the high intensity work. And that’s what we want to address, head on in today’s episode. So welcome again. Dr. Seiler, thank

Dr. Steven Seiler 11:35

you very much. I’m excited. This is actually I love to talk about interval training, believe it or not,

11:41

yeah, very good.

Trevor Connor 11:42

Well, you’ve written several really fascinating studies on interval work. And we’ll get to those in a minute. But I mean, that’s actually all of our listeners. Now, we’re very familiar with your your reviews, talking about the 8020 principle, but a lot of your research has really been focused on how to execute intervals, what are the most effective intervals? What sort of adaptations? Do you see? I mean, it’s been quite fascinating work.

Dr. Steven Seiler 12:05

Yeah. And to be honest, I came to this field from the position of put the hammer down, no pain, no gain. So most of the work on the 8020 has been just a kind of a corrective for everything I’ve done wrong myself, over many years. And then the interval training was kind of the first love from a physiological standpoint.

Trevor Connor 12:29

Yeah. And so I actually just read last night, you had a paper that was about putting the D in demanding and it was all about what is the the hardest interval work you can do? How, what’s the worst way you can torture yourself? And then even give examples at the end?

Dr. Steven Seiler 12:45

Well, I put it out on Twitter, I asked that question, people sent me their workouts and it kind of got started by the famous 20 times 400 on the track, which is, you know, one of the legendary workouts of Jim Ryan. And those of you who have run track and field will almost always have heard of or tried to do something approaching this 20 times 400 meters. So anyway, got started. There was what’s your legendary what, what’s your toughest workout? And then I kind of tried to build up a bit of an article around that.

13:18

Fantastic. I could see why that would appeal to a guy like Trevor, he likes to hurt himself a lot too often, he might say,

Trevor Connor 13:24

so so hands down my hardest when I was living in Canada, my coach who Shang ameria had us do these team time trials. So it was we one time had to do 10 by 12 minutes, teen time traveling. So it was four of us. And we had two Olympians in my group where you just rotate each of you takes a 32nd roll. And we all got into this mode of Let’s see who cracks first. And I don’t know how I survived. But all four of us survived. And my friend Derek who was the our fourth and I wrote back together, we’re on the bike path in Victoria. And this woman who had to be under 16 on a city bike passes us on the bike. I look at Derek and I say, should we catch her? Derek looks at me and goes.

Dr. Steven Seiler 14:15

You had empty the tank.

14:17

There are many ways to do it. But that sounds like sometimes

Dr. Steven Seiler 14:19

12 minutes?

14:21

No, not fun.

Trevor Connor 14:22

No, there was nothing fun at all, whatsoever.

Dr. Steven Seiler 14:26

No. And I think that’s part of our discussion that we need to have is this issue of the so called epic orc outs and what is their value? They’re great for storytelling, they give you something to remember. But you know, how much do they How do they fit into your training? You know, that’s another issue. Very good point.

Trevor Connor 14:45

Before we get into all this, there are a lot of the questions were actually kind of higher level, getting out some some biases or overall concepts. So I think we need to hit you or get your particular biases about these because I think it’ll give context when we get more specifically into intervals. So these are the questions about should you be doing intervals by heart rate versus power? Should you be doing it as percentage of Max heart rate or or vo to max power or percentage of threshold? And then also just talking about that should we be going through for specificity versus really trying to optimize physiological response? So those are three questions, we got hit with a lot. And really interested in hearing how you feel about each of those.

Dr. Steven Seiler 15:29

Well, I guess I need to start by saying that I’m speaking to this audience, which I know is primarily a cycling audience. But it’s important to remember that, or at least, I think it’s important to remember that, at least when I all of the research I’ve done has been across different movement modalities, you know, cross country skiing, cycling, running, orienteering, rowing. So I’ve tried to look at this from a kind of a universal perspective. And when you have that in the back of your mind, and then you remember that, for example, measuring power, which is become extremely normal and useful in cycling, is just not relevant in some of those other modalities. So I tried to look for, you know, what, what are the what’s the common ground, and it is still the physiology that is the common ground. And so I don’t want to throw out the physiology with the proverbial bathwater. Here, it is, it’s the physiology that represents the that shapes the power duration curve, for example. So as long as we keep that in mind, then we can work with both, you know, that we can calibrate the power measurements with some with some physiology, and then use the power and not have to measure the lactate or the heart rate all the time. So I’m perfectly comfortable with moving across in between these different modalities, but but it is worth remembering that you know, like the physiology is still the backdrop. It’s still the the universal that doesn’t go away.

Trevor Connor 17:02

Great answer. So now what about, I know you have done a lot of your prescriptions, and certainly when we get to talking about your interval studies, you talked about things done at a max heart rate, or in cycling, it is very popular to talk about percentage of FTP,

Dr. Steven Seiler 17:18

right. And that’s fine, I don’t have, again, as long as we kind of figure make sure that we’re speaking the same language, that’s been some of the, you know, we spend some time talking about how to test FTP, and so forth. All of this is just for me an issue of making sure that we’re all on the same page that if you say FTP, and I say FTP, that hopefully, we’re not actually talking about two very different things. And sometimes it seems like we, it gets there, because of different protocols, and, and so forth. So if as long as we’re clear on what we think FTP is, then we can connect it to heart rate into other stuff, and, and calibrate and move forward and just use the percentage FTP, if that’s comfortable for people, my concern, and I’m always trying to help people avoid making some of these very typical training mistakes. And the most typical is an overestimation of, let’s put it in quotes thresholds, which leads to an overestimation of the aerobic threshold and low intensity training being done at too high of an intensity, that is a very typical scenario that I try to help people avoid.

Trevor Connor 18:38

So we actually, before we started recording, we were talking here and brought up the fact that we all believe, interval, the actual protocol of interval work should be kept simple. But the act of execution can actually be very, very difficult, even with simple linear work. And I think this is one of those places where you see that because I once wrote an article about threshold, what exactly is threshold and out of interest, I looked at the different definitions, and I found close to 30, different definitions that are all going to give you a slightly different number. So when you say, you know, make sure we’re all talking about the same thing with threshold, that’s can be extraordinarily hard to do. And even so mean, Max, heart rate is Max heart rate. And you can talk about percentage of Max heart rate, but I’ve seen people who have a, you know, good time trial is gonna have a threshold, that’s 90 95% of their max heart rate were less experienced rider, their threshold might be at 85%. So if you tell somebody to go and do intervals at 88% of Max heart rate, it’s gonna be different things for different people. What I’m kind of getting at here is trying to just find a simple number and say, do your interval work at this number, and that’s going to have this particular training adaptation is actually a much harder thing to do than you think.

Dr. Steven Seiler 19:54

Oh, I agree. And and that’s kind of why our research has moved in the direction of is just To give athletes a basic prescription, and then let them solve the prescription or kind of, even in papers described it as an equation, it’s like giving someone an equation and say, Alright, solve for x. And x in this case just becomes your average power. For that interval session. You solve the equation, I say, I want you to do four times eight minutes. With two minute recovery, I want you to have the highest average power for the workout that you’re able to maintain it kind of a training max. So that’s, that’s I’ve given them an equation and how they solve it. So that has kind of become our way of doing this in the laboratory. And I think it works out pretty well. Because if we give them the prescription, then yeah, then we don’t have to, we’re not really telling them, I want you to be at 91% of heart rate, or I want you to be at four millimolar lactate, we’re just saying solve the equation. But then what we find is that they tend to fall into some kind of typical ranges for heart rate for blood lactate, for perceived exertion, and so forth. So it becomes Could you explain that a

21:16

little bit better, I would imagine people out there want you to give them an equation where they can just plug in numbers, but what you’re talking about is going out onto the road and solving the equation out on the road is do I have that correct,

Dr. Steven Seiler 21:31

or they can solve it on their on their domitor, you know, in Swift or whatever, I can give you lots of cold hard numbers, let’s go to these three prescriptions that we’ve used a lot in papers. The first one was four times four minutes. And now. And the reason we started using four times four is because back in around 2000 567, it was a popular that there were several papers that got published based on four times four, and they came from Norway, they came from another research group in Norway that really pushed four times four. And so we said, All right, well, let’s incorporate four times four into our study, even though we probably we don’t think four times four is magical, we’re going to use it. And then we also knew from our descriptive research, you know, where we had gone in and looked at the best athletes we could find. We knew that they tended to do longer intervals and collect more minutes. So then we said, Alright, let’s double four times four and have a four times eight. And then we went one step further and said, well, let’s go ahead and go four times 16 as a third, because we think now we’re starting to get kind of into that, more like a threshold intensity, typical, you know, and I’m putting threshold in quotes. So that’s how this emerged, as we just said, Let’s, you know, it was a combination of what we knew athletes were actually doing, what was popular in the literature, in the research literature, and then trying to cover the spectrum, in the in the zone, the intensity zone model, this five zone intensity from upper end of threshold, zone three, you know, 12345 model, and then zone four, zone five. So that was where we wanted to be. And it turned out that if I prescribe four times four minutes to a group of athletes, four times four minutes with two minute recovery between each and when I say recovery, we basically said, do whatever intensity you want during the two minutes, and generally it was basically just keeping the pedals moving, they chose. So maybe 100 watts or something like that. So four times, four minutes, two minute recovery, he didn’t get it, you know, give us your best effort in the lab, and we’re measuring everything. And then we’re periodically measuring blood lactate, we’re measuring perceived exertion asking them, you know, what’s the perceived RP score. So we collect this data, and we end up collecting data on literally hundreds of interval sessions, hundreds of interval sessions prescribed as four times four minutes, hundreds prescribed as four times eight minutes, and hundreds of interval sessions prescribed as four times 16 minutes. And I’m not exaggerating the one study, we have 500 training sessions documented for each of these prescriptions by the same athlete. So we’re comparing apples with apples, we’re comparing Thor that does four times for a certain number of times during the training study, and four times eight and four times 16. So we’ve got direct comparisons of how they solve these three different equations. So it’s, it’s pretty solid data. And of course, there’s variation in how people solve these and in their fitness and so forth. But if you look at the averages and tendencies, it gives some pretty clear guidelines, some pretty clear rules of thumb. So if I start with four times 16 minutes, when we prescribe that, that Will, on average end up at about four to five millimolar blood lactate, on average, meaning they’re basically at their maximum lactate steady state, it’ll vary the lowest I went in and looked at the data. And you know, the lowest were down two and a half millimolar. And the highest were 10. You know, they’re at 10 millimolar. And that’s consistent with the way the maximal lactate steady state works. But four times 16 will put them pretty darn close to the so called mlss, or this, that second threshold, anaerobic threshold, what their heart rate will start at about 86% of Max, and it’ll climb up to around 9091. During that, four times, 16 minutes. So that’s kind of a template for that session, that kind of session. Now, if we go to four times eight minutes, we prescribe this again, we’re just saying, you know, do it with the best intensity you can manage. And when we’ve done these studies, they’re, they’re in groups. They’re all you know how it is. So they’re basically looking at each other. And they’re motivated to do to give it a good, you know, to work out hard, they’re coming in during the winter months, and they’re excited and they want to perform. So that’s the backdrop, four times eight minutes, where do they end up, they start at about 88%. And then they end up at about 90 to 93% of heart rate max over the course of the workout. And their blood lactate ends up being on average about nine millimolar.

Trevor Connor 26:39

Just very quickly mentioned, for for any of our listeners who don’t know this, there, there is individual variants, but you’re considered to be right around threshold at about four millimoles.

Dr. Steven Seiler 26:50

Yeah, and for cycling, for sure, it can easily be higher than that there is a tendency for cycling, I would say for it to be for a fair number of people a little higher than that. Because of the amount of muscle mass involved, it’s a little bit less, maybe there’s just some, I don’t want to get into too much of the physiology. But we’ve got some reasonably good data from others that show that typical maximum lactate steady state, concentration of lactate in cycling is tends to be a little above four millimolar versus in elite runners that may be a little below four millimolar. So but let’s not Yeah, this is splitting

Trevor Connor 27:26

hairs, just saying that at eight or nine millimoles. You’re above threshold away. Yeah,

Dr. Steven Seiler 27:32

yeah, for sure. At eight or nine, you’re definitely, at least in this group. They’re above and they’re working hard. And they’re, you know, in heart rate drift, so it’s not stable. So that’s the four times eight. And then finally, the four times four, they start you know that after the first interval, they’re at about 91% of heart max heart rate, again, I’m taking the average of 500 sessions with with the variation within there at about 91. And they drift up to around 95 96%. So they’re really you know, they’re getting cooked. And they’re at 12 and a half millimolar, on average, nearly 13 millimolar, blood lactate. And for most people, you’ve You know, you’re you’re feeling that you’re starting to fight to keep the wheels going around. And then if we were to go through their perceived exertion, it’s the same kind of tendency that the perceived exertion is higher for the shorter intervals than it is for the longer ones. All this put together gives us a fairly good template for if I prescribe in this range, then here’s what’s going to happen. It kind of puts the people at the at the upper end of zone three, or you know, right around threshold, the anaerobic threshold in the middle of zone four. And then in zone five is the prescription puts them were kind of where we want them to be. And then the question becomes, okay, yeah, where do we want them to be? What is is there advantages or disadvantages to these different protocols,

Trevor Connor 28:56

these different prescriptions, and you put out three absolutely fascinating studies looking at these three types of intervals and the different sort of impacts they have on adaptations on the athlete on the response, which I hope we’re really going to dig into right now. And some of the some of the conclusions, I think we’re going to see is counter to what I think a lot of people would would believe about intervals, starting out. So you’re saying these three different types are people talk about threshold intervals, or they talk about vo, two max intervals, you design these specifically to each each of these types fits into one of those categories. Correct. So you’re saying the four by 16 are kind of your threshold intervals,

Dr. Steven Seiler 29:38

but they give us some representative prescriptions. And so it’s really important for me to say there’s nothing magical about any of these and I’m not trying to sell one. So it’s like, well, Steven sells the four times eight, that’s his, that’s the cyler intervals or whatever. No, four times eight was one of the models we’ve used and it turned out seemed to result in good adaptation, but it is Maybe could have been seven times six or, you know, you know, I’m saying it, we think it’s more to do with the total duration that we’re prescribing that that actually is a constraining factor that helps that we can use as coaches or, you know, to prescribe and help our athletes be where we want them to be, is, what’s the total amount of number of minutes that I want them to be working, accumulating, work at this intensity, and then I need to backup now, because we get so focused on the individual interval session that we forget the forest here, we get so focused on the tree, that we forget the forest in the forest is this, let’s let’s say you train five times a week on average day weekend weekend. So that’s about 250 sessions per year, if my math is right, plus minus, and let’s say you do an 8020 model where you say, Yep, 20% of my sessions are going to be seriously hard. All right, then that’s around 50 hit sessions each year. And then you may end up doing a few more than that. But a minimum, typical, reo listeners are doing 50 to 100 hard sessions per season or per year, as part of their training, right. So we have to think about is, when we’re prescribing this, we’re trying to prescribe a an interval training prescription base, that gives us the signals that we need over time, over these hundred sessions that they may be, without stressing more than necessary. So I always get back to this issue is, is I want to create a signal, I’ve got to live with some stress, yes, we’re gonna stress the system big time. But we don’t need to stress the system more than necessary, then it becomes unsustainable. This is about the big philosophy, this is the big picture. And sometimes we forget this because we get so focused on the individual details of the workout, that maybe are not as important as we think. And we forget the big issue, which is, hey, I need to make sure that these hundred hard workouts I do in a year have some there’s a plan here and that there’s a sustainability built into them. So that I’m, I’m progressing, I’m not biting off more than I can choose. So that is part of the the big picture that needs to really be for me, that that’s the foundation for everything that I’m trying to prescribe. If I’m working with my daughter, who I love dearly, I don’t want her to become overtrained or fall apart. You know, I want what’s best for her. I’m trying to think about how am I going to help her with this hundred sessions? I know she’s going to do in the course. So

Trevor Connor 32:47

it’s about maximizing adaptations, not about maximizing pain? Absolutely not.

Dr. Steven Seiler 32:54

This is one of the things where we do things wrong. And now we’re back to that issue of these epic workouts. They’re great to have his stories, but they’re not sustainable there. That’s not what makes you a champion is is that single epic session that you did back in April, you know, what makes you a champion is the hundred sessions that you were able to do because you stayed healthy. That you Does that make sense? I mean, that’s, that’s what it every behind every champion is a long period of being able to do the planning the plan sessions, that they stayed healthy. They built in enough rest and flexibility so that they didn’t go over the edge. And they had this sustained period of development. That’s what I try to, you know, at least increase the likelihood that we’ll achieve,

Trevor Connor 33:49

can remember who it was. But we had a world tour pro interviewed a few years ago. And he basically said exactly that. He said, Every once in a while, it’s fun to go out and absolutely destroy yourself with an interval session. But he said that’s really just to give yourself some competence, said most of the time, I like to go out, get the work done. But keep something in the legs so that the next day I can still do some quality. And the next day I can do still do some quality and and look at in the context of a whole putting together a whole week as opposed to some interval session that absolutely destroys me.

Dr. Steven Seiler 34:27

Exactly. And a whole week becomes a month, which becomes you know, a preparation period. So this is for me the the real lesson to learn from the best athletes is,

34:39

I would say almost a sense of pacing, their training, not just pacing, a race, but pacing their preparation period pacing their build up, and making sure that they’re leaving something in the tank during training so that they can empty the tank in racing. It comes down to discipline. Honestly those Ridiculous rides that we sometimes do, or workouts that we sometimes do, like you said, are about confidence, they’re about fun. Sometimes you need that. And that’s very helpful in the long term. But yeah, overall discipline is, is what we’re talking about here and reeling it in when necessary.

Dr. Steven Seiler 35:16

Absolutely. And there’s room for that flexibility. Let’s take the example. And I’ll use my daughter who runs right now. And so and I’m kind of her coach, or I’m not kind of I am her coach. And so one of our bread and butter Sessions is the eight minute intervals. But we flex a little bit on how many, for example, you know, the bread and butter is four times eight, but I gotta tell you, My daughter has a tendency of wanting to do things a little, you know, if four is good, she thinks five is better. So she has a tendency to make four times eight to five times eight. And I’m okay with that, you know, as I write, you know, five times eight, and now five times eight is kind of what she likes best. she collects 40 minutes of work. But we have, we flex a little bit, you know, and sometimes in the prescription, I’ll say, Hey, if you’re feeling a little tired, or if, you know, back it down to three or four, if you’re feeling good pop add an extra interval, you know, so, so within the basic prescription, I don’t think anybody should feel uncomfortable with flexing a little bit up or down around that number, based on where they are whether, for example, there’s a race in three days, they don’t want to push too deep, or whether they feel a little down. So I think that’s a useful thing to have in mind is that you can flex both the number of intervals and the power output. So you’ve got both a duration and an intensity, some room to play with. And you can kind of use them back and forth against each other as you’re progressing. During the season. I don’t know if that makes sense. But you know, I might go three times they, the next week, four times eight, then the third week five times eight in a progression. And then when we start a new progression, we may go at a started a bit higher power. So we can use both a bit of a progression in total accumulated duration, and the progression and what people tend to be most focused on, which is the actual intensity.

Trevor Connor 37:20

All right, so this is a third episode in a row with Brent bookwalter on the show, but it always has great things to say. And he was the pro who gave me that quote I mentioned to Dr. Seiler. And it’s one of my favorites because it really shows the training mindset of a pro. Notice the similarities between what Brad and Dr. Seiler were saying,

37:39

as much is cycling as a sport, where your hard work and your commitment, and then the amount of push yourself and the money do does yield benefit. Without a doubt there’s a point when it goes the other way and actually starts to hurt you in some ways, it is a little bit of a no pain, no gain sport, because you’re not going to get better out just by sitting on your couch, or you’re not going to get better just by by doing easy rides all the time. But I’m just as much it’s a it’s a sort of moderation and knowing when to say when it isn’t just about, the more you can do, the better you’ll be otherwise, um, you know, I don’t think it would be as a unique and beautiful sport and each person ultimately, regardless of the coaches you have, or the support now review that ultimately, it’s your responsibility to figure out how all those pieces come together and what’s going to make you the best. So continuing along with this when you’re going out and doing intervals, again, do

Trevor Connor 38:37

you think there’s a balance there? If somebody gives you a threshold workout or two bottles type workout? Should you just be going until you crack? Or is there a point where you go, another set just isn’t worth the cost?

38:50

Yeah, that’s definitely I think I’ve often and I think it’s important. For me personally, it’s important that I’m really in the loop with my coach. And we’re on the same page in regards to my workouts, not only what the type of interval is aimed to aim to achieve ramseur accomplished but the ride as a whole, depending on where it fits in my period as a nation and my training and race program, a threshold workout, for instance, one day, it may be for me to kind of go past that, when that goes go almost like a race. So as deep as I can go as long as I can go to failure and actually push a little through. I think at certain times, there’s some value to that physiologically and psychologically to but I would say more times than not, I would say the majority of the time is the voice of reason sort of wins over and once once I’m not able to effectively and productively do whatever workout or, or power number higher right number or whatever parameter we’re working with. Then he cut it and he had that song when you factor that in and make sure to make good notes about it and look at as many variables as we can and the depth for the feature section. So that was it. You would say when somebody is going out and doing intervals, that’s the the point where you say, Okay, I’m done for today’s as soon as you can’t do it with sufficient quality, you’re done. Yeah, yeah, the most of the time, like I said, I think there is I think there is some value to, to going, going past and really growing, pushing yourself to failure past past the point, once in a while. But that’s not something that I’m doing on a weekly basis, and definitely not during the season in between races. Or, like, what I really like is, yet you have a workout you have is down, you have a maybe even a number, you know, if you once you drop below 20% of this number, then you stop. But then like a, like a basic overview, like, at the end of the day, this is how this is how you should feel, or this is what this is a productive workout. And some days productive day on this particular day. And is really one thing in the last two miles of ride really just being really haven’t given everything on the road. But most of the days now that isn’t the case, especially with I think where I’m at training now it’s, it’s a lot about laying down these really fine layers and getting the accumulated load over and over. So if you go to, if you go to total failure one day, it’s unlikely that you’re going to be able to come back the second, third or fourth day and do anything productive. So net productivity is actually enhanced by knowing that point where you should back off, keep a little in the tank for the next day or two days from now, three days from then, and you know, get back on, you know, you can do it again the next day. That’s the thing you can always add on add on more. But once it’s done, you can take it away. There’s no way you can undo an interval, but you can always add more later in the rider and the next ride or the next week.

Trevor Connor 41:48

That was actually going to be my next question is, is it worth crushing yourself one day? Or is it better to keep the day a little easier, so you can then go out and do quality again the next day?

42:00

Yeah, I would. Personally I’d definitely be in favor of stacking up the good quality on top of each other repetitively time allows, I think it’s a sort of a common training misconception. And part of it is fueled by no people scheduled people out of busy workweek. And they go, they have a free couple days on a weekend or they take a long lunch break one day, and they really want to make the most of it. And I’ll be the first one to say it feels good to, we all kind of get high off that feeling, you know, that we get in a race, you know, when you’re in a break away, you’re really giving your all and putting it all on the line in the empty yourself and you get done, you have this sort of calm clarity, because you physically gave everything you had mentally gave everything you had. But I think productively training, it isn’t beneficial or realistic to do that, you know, on a weekly basis, or multiple times per week, I think I think a lot of people would be better served by a little moderation backing it down a little bit. And then you know, knowing maybe, maybe they didn’t totally crush themselves on their Saturday ride. But because of that, when they had Tuesday, they’re still going to be able to get even if it’s only an hour, and they’re still going to be able to get some quality and as opposed to still being in a body bag come Tuesday and eating all summer next week and they’re recovered.

Trevor Connor 43:16

Back to the show. You know, I got to say our last episode, when we were talking about threshold and the zones, you actually did an hour time trial on your ergometer to determine your FTP. And if I didn’t say it, then let me say thank you for torturing yourself for the sake of our podcast that was truly appreciate it. So

Dr. Steven Seiler 43:36

let’s say I did it just for you guys. I mean, I’ve actually done. I’ve done that our power now about four or five times in the last year. So so it’s in the interest of science there. Yeah,

43:50

well idea.

Trevor Connor 43:51

So I felt I owed you. And last week I went out to attempt your four by 16. And I will admit I got to the end of the third one and went

Dr. Steven Seiler 43:58

Yeah, that’s enough. Yeah. And there we go. And that’s and it probably wasn’t enough. So that’s, I think that’s a really important message that’s consistent with this issue, which is the goal is not to kill yourself. The goal is not to keep shoveling until you can never get out of the hole. A goal is to create a stimulus for adaptation. And because you’re an experienced cyclist, you have a feeling for Okay, I’m there I need I’m where I need to go with three times 16. Good, good on you. Maybe another time you’ll want to go for that’s fine.

Chris Case 44:32

This might take us a little off track. But is there anything to replace experience when it comes to determining whether you should do that fourth or fifth on a day to help athletes understand the feeling that you have when you’re on the edge should go you know like you were saying flex a little above or flex or bring it back down? Is there anything that replaces experience?

Dr. Steven Seiler 44:57

No, I think at least some people experience, you know, what I hope we can do with these these messages is that we can help people to get be on the right track with just the prescription itself and some basics. But then, within that prescription, I think they need to do it that first time and maybe the second time and start to get a feeling for what is what’s four times eight feel like, and what do I, where do I need to start? What’s the initial power and initial feeling and then guide, you know, go from there. And then I think, again, I go back to those that I’ve worked with closest to me, who tend to be very motivated. Often, my job has been to put on the brakes a little bit, and often say, you know, four is enough, don’t, you don’t need to do five. Because, you know, if they go just a little too deep in the world, and they struggle the next day or the next two days, now we’re defeating our purpose, because now I’m losing something else I think is important, which is, is the consistency of training. I want them to be able to get back on the bike the next day for an easy two hour ride, or that I hope your listeners will figure out well pay attention to and see where what is my sustainability limit? What is my durability? You know, what do I handle? Is it four times eight? Or do I handle five times a day? Can I handle that? 45 minute, at 92%? Heart Rate Max, you know? Or does it put me a bit over the top one

Trevor Connor 46:30

of the guides I give my athletes is I want to see consistency. So if I give an athlete four by eight, and let’s say they do the first one, averaging 280 watts, and the second one, maybe they average to 75. The third one, they average 273. I’m okay with all that. But let’s say they start the fourth one, and they’re sitting at 250 watts, you pull the plug, the quality’s not there anymore,

Dr. Steven Seiler 46:52

they’re done. That’s totally agree. And that’s one thing I can say is that in our training studies, you know, that’s what we basically say is shoot for an even power distribution. And, and in general, they pull that off the prescription that led to the most failures, or the most failed pacing, where they the power falls apart. Which one do you think it is of 4448 416,

Trevor Connor 47:19

four by fours, four by fours.

Dr. Steven Seiler 47:20

Without question, four by four is the one that they tend to overcook. And that’s another reason why we tend to say, four by eight, he tend to get it right, we get you where we want you to be, we get the quality minutes, and we go home. And we don’t have as many of those kind of bad experiences that happen fairly often. And those four by fours. So so that, again, was part of that learning that we we achieved with with just hundreds of sessions.

Trevor Connor 47:51

So when I attempted those four by 16 last week, that’s actually why I pulled the plug in the fourth because I the first three were all within four watt, averaging one another. So they were all very consistent started, just started the fourth and went, there’s no way I can do that power again. So I was done.

Dr. Steven Seiler 48:09

Yeah, so you maybe were glycogen depleted? You know, hard to say. But I used to row competitively. And we had a three times 20 minutes session that we did. And we’re in singles, you know, when we’re cooking each other for, but it had a very strong tendency that we would do two really good quality 220 minute bouts. And then the third one, we’d be kind of looking each other like are you tired? Yeah. Yeah. We’d kind of go through the motions on the third 20 minute bout. But if I’d if we’d had power, I’m sure that it was way down. You know that third one? So how much did we get out of doing that third one, I’m not sure.

Trevor Connor 48:51

So when I have athletes who don’t have power, and they can’t tell they’re consistent the way I prescribe this sort of intervals, I have them do it on a climb. And I give them I tell them, You need to pick a start location and a finish location that works out to about eight minutes. And you start at the same place every time. And I said, you always have to finish within about 10 seconds at the same time. And if you can’t be within 10 seconds, the quality’s gone, and you’re done.

Dr. Steven Seiler 49:17

And I think another question, I’m going to just try to anticipate a question that people will have, and that is, yeah, okay. What about heart rate? What if my heart rate slides up above the so called zone for limit? Do I do I bring it down? Do I reduce the power? And then then I would go back to what you were saying is basically look, if you’re holding the power on that fourth interval, even though your heart rate is sliding up, just finish it. If you feel good and you’re balanced, you know, you’re able to hold the power, then let that be the judge. And if you slit up to 94%, then we live with that. Okay, let the prescription be the judge and just solve the equation. But if you’re falling apart, then that’s that’s a guide to shut it down. You know, if if 280 becomes 250, then I agree with you 100% that then basically, the signal has been achieved, especially when you’re on a trainer, because dehydration is such a big factor in heart rate. And

Trevor Connor 50:16

whenever I have athletes do intervals on the trainer, they always see a very high heart rate in that final interval, just because they’ve lost so much fluid.

Dr. Steven Seiler 50:25

Yeah, and, and this is a little bit of mechanics on indoor training, as guys get a big fan, you know, you need you need to have the the cooling. So that was my first rule is when I bought myself a big fan with three, and I’ve always got it on the highest speed, and try to simulate that good air ventilation that we get outdoors. Otherwise, it is a totally different scenario. So this is this is really important that people do not underestimate the importance of the evaporative cooling bonus you get with good wind movement or air movement. And then of course, you know, drinking. Yep, so that’s, that’s part of just the maintenance of your physiology, you know, taken care of the engine that needs to be done, both indoors and outdoors. But indoors, it’s a particular problem just because you don’t get the air movement. And if you’re, if you’re sweating, and you’re pooling drops of sweat below you, that’s a good sign that you’re not getting enough air movement.

Trevor Connor 51:26

Now I agree 100%. And as somebody who used to run trainer classes, please have the big fan because some of us have to mop up afterwards.

Chris Case 51:43

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52:54

Trevor Connor 52:54

going back to the three intervals, the four by fours, the four by eights and the four by six teams. We mentioned earlier that people would instantly think okay, four by 16. Those are threshold intervals four by fours. Those are vo two max intervals. And you those are what you’d pick to train those systems. But it seems like what you found in the studies is there isn’t that specificity of intensity that everybody believes so strongly. Is that accurate? Is that what you found that they seem to all pretty much train the same

Dr. Steven Seiler 53:23

it is. And if we really think about it, it shouldn’t be so hard to understand or that we get our heads around this is that because we have a tendency to sync up dimensionally around intensity, but its intensity times duration, that ends up being the determinant of the molecular signal that we’re creating. We’re and there’s got to be some threshold. So you can’t just say well, if I go long enough at this super low intensity, then I get the same signal under the curve or whatever. But in that area of say 90, you know at 90% of Max, just small adjustments up or down in intensity can give you pretty big differences in your sustainable or, or maximal accumulated duration. And so then the question becomes, okay, how do we how do we manipulate that? How do we use it? And even back in the 60s, one of the sweetest physiologist, a guy named pare australind. He wrote this in a book and it was always very important to me the question he asked, he says, We don’t know the answer to this question, but what is better to train at 100% of the maximum oxygen consumption for 16 minutes or at 90%? For 40 minutes. So so he already then was coming to grips with this interplay between intensity and duration in the interval training, intensity range. And really that’s what we’ve been trying to get our heads around and trying to understand how you elite athletes solve this, what’s the most sustainable way to go. And it seems like the elite athletes, consistently, what we see is they, they choose to back off just a little bit on the intensity and collect minutes, collect more minutes. And that’s how we started seeing this 3040 minutes was a typical good amount of interval training to accumulate during a session.

Trevor Connor 55:27

And so if I remember correctly, in one of your studies, you found that the four by eights, compared to the four by fours, athletes found that an easier workout to execute, yet you are seen across the board, more consistent and better gains with the four by eights and the four by fours arguing for this, maybe backing down a little bit and doing more is better.

Dr. Steven Seiler 55:50

That’s right, if I talk about the different ways that I’ve tried to pursue these questions, part of it has been we’ve been lucky enough to have really good data from the best performers in the world and in a number of different sports. So that’s been part of our knowledge base. And then we’ve used some of that to go into the lab and design experimental studies, like you’ve been talking about, you know, where we use the 4448 and 416, we kind of operationalize things we’ve seen in the form of an experimental trial. And then, of course, just to try to keep moving with with people, we were constantly asking questions and discussing and trying to understand how people perceive these different things. So the combination of all that seems to be that we can generate a good physiological stimulus for adaptation, both so called peripheral peripheral adaptations, like, you know, changes in mitochondria and lactate threshold. And then also the central adaptations. And there is a lot of crossover that we there back 20 years ago, you would have heard a lot more discussion about, well, this workout is for peripheral peripheral adaptations, and this workout is for central or cardiac adaptations. But boy, you know, there’s just not a lot of support for that way of thinking anymore based on what we see in the in the data. So the body is a is a single entity and the signals that you’re generating have multiple effects, both cardiac, muscular and so forth. And, and that seems to be the real reality that there’s a lot of overlapping.

Trevor Connor 57:26

So I mean, Chris and I talked about this very early on in the show that we don’t want to get too much into all the different physiological mechanisms and start throwing up tons of terms out there. But we did pick one that we said we’re going to keep bringing this up in the show which is the the PG c one alpha pathway, because it is responsible for so many of the aerobic adaptations that you see in an athlete and part of the reason we brought that up is all the research showing that almost all training ultimately hits this pathway and promotes it so whether you’re doing sprint work or you’re out doing a five hour long ride, they both promote this PG c one alpha pathway that then promotes mitochondrial growth promotes pillar ization promotes a lot of what you think of as as as endurance training. I’m kind of going into the weeds here but it’s really kind of physiological back in what you’re saying of it. Isn’t that as specific as people think.

Dr. Steven Seiler 58:22

And you’re pulling a Trevor here apparently you’re known for this. What are they? What do you guys call this a science bomb or something like,

Trevor Connor 58:29

nerd bomb right.

58:32

Thank you.

Dr. Steven Seiler 58:33

Yeah. So that makes it easier for me because now I can come across as they’re really straightforward scientists that doesn’t do all these nerve bombs. So that’s the

Trevor Connor 58:42

perfect that what I’m becoming here.

Dr. Steven Seiler 58:49

My kids, I’m going to tell them I was I was in a conversation with two people and I wasn’t the nerdiest one in the conversation.

Trevor Connor 59:03

Let’s see, what do I have working against me? I’m Canadian. an Uber nerd. What else?

59:10

That’s why I’m here.

Dr. Steven Seiler 59:13

We speak the same language. It’s it’s all spreading the love. So we’re good.

Trevor Connor 59:18

And can you believe I’m single?

Dr. Steven Seiler 59:23

I can actually because you remind me a little bit of me and I know my challenges so it takes a special woman.

Trevor Connor 59:32

I’ve been getting people to encourage me to go on the dating scene. And I already know my as soon as I sit down on that first date for dinner, like the first thing I’m going to say about myself is one of the top physiologist in the world called me a nerd.

Dr. Steven Seiler 59:49

Well, sooner or later, you’ll find the girl who finds that charming so it’s a you know,

59:55

math talk listeners out there that love nerds love Canadian nerds. Please email Trevor,

Trevor Connor 1:00:03

first, get some help.

Dr. Steven Seiler 1:00:05

We’re not being fair. I’m sure there’s more to you than just the nerd part. You know, we all have. No. I was giving you a chance. No, I

1:00:20

look, you.

1:00:21

Look, this

Trevor Connor 1:00:22

is what you tell every athlete, you got to know where you’re at. I know where I’m at.

Dr. Steven Seiler 1:00:28

We’ve totally digress. Now.

Trevor Connor 1:00:31

We have a quick I just got to quickly share one stories, you know, where I got this from my father loves reading research in his field. And one time he was at a friend’s cottage sitting on the dock reading research, and the friend’s son comes up to him, he goes, What are you doing? My father goes, I’m reading research and kid goes, Well, why are you doing that? My dad goes, Well, I’m on vacation. And don’t you like to do what you really enjoy when you’re on vacation? could just look something goes, you’re weird.

Dr. Steven Seiler 1:01:03

Oh, trust me, I deal with this every day. I have two kids that call me the absent minded professor. So. So that’s why anytime I have the opportunity to demonstrate to them in some way that I have a usefulness for society than I am really happy.

1:01:18

You just have to remind them, of course of the first time we spoke with you when Trevor dubbed you the Jay Z of physiology.

Dr. Steven Seiler 1:01:27

Exactly. So I have used but unfortunately, my son, it only lasts, you know, he’s impressed for about 12 seconds, so I constantly. So this time, I’m going to say look, I was in a conversation with only with two other people and I was not the nerdiest one in the group. So that that’s going to be my next effort to breath in. Yeah,

Trevor Connor 1:01:49

yeah, I will back you on that one. You can play those back. So here’s me saying you are not the biggest nerd.

Dr. Steven Seiler 1:01:57

So by now we’ve lost half the audience. They’ve gone to the refrigerator, I think and hoping that we get back on track eventually.

Trevor Connor 1:02:05

Yeah, so let’s let’s get back to him. So I want to get back to this whole. People really focus on the the specificity of intensity. And I did really want to ask you about this because I ended up actually in a think it was a Twitter conversation with a listener who actually went deep into the weeds. And one of your studies looked at these four by six teams, that they were at approximately 87 88% of Max heart rate and did the calculations and discovered that, that works out for most people a few beats per minute below FTP or threshold or mlss, which that puts that work in your zone two on a three zone model. And therefore these four by 16, don’t fit in your polarized model and your own research contradicts your polarized model. This is literally what I was hit with.

Dr. Steven Seiler 1:02:58

Yeah, well, I think what we end up with is, is that there’s some fuzziness in the formula, molar power determination, or the threshold determination. There’s some fuzziness in the execution of the workout, and, and there’s some heart rate drift here. So what we see is that when we prescribe this, our subjects end up right at that boundary between zone two and zone three in this three zone model you’re talking about. So So yeah, I mean, it’s, it’s somewhere in between, it’s right at the edge, they drift, they the first 16 minute bout, they’re at 86 87%, which would be kind of zone Three, two in that. And then by the time they get to the end of the workout, they’re at 91%, which would we typically say they’ve jumped in or they’ve eased into zone four. This is where these zones, they’re somewhat arbitrary. Because heart rate drift, you know, what, what are you using to distinguish where they are? Is it blood lactate is it heart rate, and the bottom line is, guys, we got to remember that there is essentially no such thing as a steady state in training. And I caution people and I think it’s important to have that in the back of your head, there is no real steady state. There’s a pseudo you know, a quasi steady state that we achieve particularly at low intensities, but even there, if we go long enough, then some kind of a threshold happens we suddenly you know, we become glycogen depleted or we become dehydrated or so forth. And this is certainly the case in during interval training, that we are not in a steady state. So based on heart rate, if we were to use that as a guide will, will tend to kind of move through these zones if we keep going long enough hard enough. So I’m I get that you know if you’re looking for arguments, but it’s not that clear cut, you know, and it particularly that four times 16 prescription does put people we’re kind of right at that wicked edge between what you might call threshold and above threshold.

Chris Case 1:05:07

I think one of the things that we’ve seen is over emphasis by some listeners, and understandably so in a way of the zones themselves that they’re literally walls between these things. And if you jump over one while you’re in another zone, and it means a completely different thing, but what we’re talking about is this blending of energy systems at all times that it’s way more porous than that if you want to take an analogy when it comes to Well, it’s not a wall, it’s more like a low lying fence or something. And you shouldn’t get caught up in these single or couple beats on one side or the other of these arbitrary barriers, these

Trevor Connor 1:05:48

Absolutely, yeah, I think that’s the message that played out so elegantly in your studies that I think we’re all trying to say here, which is, don’t get caught up in this, well, if I’m writing a 300 watts, I’m training one energy system, if I’m writing a 320 watts, I’m training a different energy system, I think the message is if you go out and do four by six teens, as hard as you can, that’s hard work. That’s high intensity work that counts towards your 20% in in the this 8020 polarized map.

Dr. Steven Seiler 1:06:20

So all three of these 4448 416 are clearly in this aerobic dominated range. Even the four four we got 12 and a half millimolar. lactate, guys, if we were to actually go in and we’ve done it, but if we actually go in and measure, you know, the oxygen consumption and calculate the energy demand, and so forth, and then calculate the actual contribution of the so called anaerobic energy system, it is small, blood lactate is high, but the actual anaerobic contribution to the total energy demand is small, really small. So we just get faked out by the huffing and puffing into lactate.

Trevor Connor 1:07:06

But I did find it interesting that you found that the four by fours did produce some gains in 32nd power.

Dr. Steven Seiler 1:07:12

Yeah, there is. Blood lactate is pretty high, which means there’s some acidosis, which probably means we’re triggering some improvements in blood in buffering capacity. Again, the here’s here, we’re back to this issue of overlapping of adaptive signals. I would say to most people, if you do regular high intensity aerobic intervals, then you are stimulating your anaerobic buffering capacity, not maximally, but you’re getting some anaerobic buffering capacity impact. And then you can top that out with just a little tweak in the direction in terms of your interval prescription if you need to. But you’re probably halfway there in terms of your anaerobic buffering, buffering capacity, adaptations range already, if you’re doing regular aerobic, high intensity intervals. That makes sense. Because there’s overlapping of these signals. Yeah, there’s, you know, some of the intracellular signals that are generated by these aerobic intervals are resulting in increases in in buffering capacity, relative to what would be if you weren’t doing it in intervals at all.

Trevor Connor 1:08:25

Yeah, and again, just gets back to this. It’s not so specific.

Dr. Steven Seiler 1:08:29

It’s not there’s no redundancy, like you’re saying that PG, one alpha, it’s there’s some redundant pathways here that are evolutionarily conserved.

Trevor Connor 1:08:38

So I actually want to just quickly bring this up, because I found a 1996 study that was in the International Journal of Sports Medicine a couple of weeks ago that I’m sure you’re very familiar with, that looked at runners of different types. So everything from 400 meter runners to marathon runners to see if specific training so do if 400 meter runners do a lot of training at that 400 meter pace? Does it make them a better 400 meter runner, and actually, the conclusions of the study was they found the the best runners in all disciplines weren’t that specific, they perform better than the runners who were very specific and going back to your polarized model. They found the fastest runners and most of the disciplines did a lot of moderate training at easier paces.

Dr. Steven Seiler 1:09:25

One of my former PhD students is expert on sprint training and on sprint performance, and I mean like Usain Bolt sprint performance, and that’s exactly what we’re looking at. We’re writing a review paper and that’s the way they train hundred meter sprint, is they use a bi polar model, that’s what they call it, and they actually train either at fairly low percentages of maximum velocity, or at 95% plus percent of maximum velocity. They don’t do much at 90 or 85%. So even there, there seems To be this kind of a bifurcation or a polarization of training that’s going on in sprinting. So we’re trying to get our heads around that as what is this universality going on here?

Trevor Connor 1:10:10

That’s fascinating. I’m looking forward to reading that study when you put it out.

Dr. Steven Seiler 1:10:13

I’m not the expert on this, but I’m just kind of making a little contribution.

Trevor Connor 1:10:17

Chris had a chance to talk with Ruth winder a pro with trek segafredo, who’s won most of the biggest races in North America, including Joe Martin and Redlands, Chris asked her about her high intensity work, you know, she talks more about the timing, or periodization of her work, and the type of work she does than focusing on the details.