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Stephen Seiler, Professor in Sport Science at the University of Adger, is internationally known for his research publications and lectures about organization of endurance training and intensity distribution. His work has influenced international research around training intensity distribution and the “polarized training model.” His work includes descriptive and experimental approaches, where he’s investigated cyclists, rowers, cross-country skiers, orienteers, and distance runners.

Dr. Seiler has published over 100 peer reviewed publications and written over 100 science articles about exercise physiology and the training process, and is a founding editorial board member of the International Journal of Sport Physiology and Performance.

Dr. Seiler grew up in the US and earned his doctoral degree from the University of Texas at Austin, but has lived and worked in Norway for 20 years. While currently a professor at the University of Agder in Kristiansand, Norway, he was previously Vice-Rector for Research and Innovation and past Dean of the Faculty of Health and Sport Science at the same university. 

He has also served on the Executive Board of the European College of Sport Science, where he founded the Elite Sport Performance Special Interest Group in 2014.

In this week’s podcast, Dr. Seiler and Sonya talk about what separates champions, data, periodization, moderation zones and more.

“I think that’s one of the things that distinguishes champions. In our work, we’ve had the luxury of being able to measure a lot of Olympic gold medalists and so forth, and one of the things that distinguishes them is, number one, they have what I call intensity discipline. They plan the work and work the plan. So if today’s plan is a three-hour easy ride, then they keep it easy. And they’re not going to let some showboat that cycles by them that says ‘ah hah, I just rode by the gold medalist,’ they don’t care because they know what they’re good for. So that’s one thing is intensity discipline. But the other thing they do is they triangulate. Us science folks, we like triangulation, meaning we use two or three different methodologies. So what I want to help my athlete do is calibrate their perception with some numbers.”

– Dr. Stephen Seiler

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Key Takeaways

  • Can you rely on wearable devices?
  • Breathing as a source of data
  • Distinguishing champions – intensity discipline and triangulations
  • How athletes can recognize how they feel
  • Sustainable training
  • Model of periodization
  • Not relying on just the numbers on your device
  • Concentration threshold
  • Rest days
  • Measuring heart rate variability




Sonya Looney: Welcome to the show, Dr. Seiler.

Dr. Stephen Seiler: Thanks. Yeah, we’ve already kind of started.

Sonya: We were chatting, and I had to interrupt you to hit the record button because you were saying so many great things already. I was like, wait, I have to catch this. Just to get back to where I interrupted you. You were saying that there’s so much data coming in right now with all of the different devices that we have. It’s like drinking out of a fire hose, and it’s hard to stay on top of how much data we have versus where the technology is. So can you just continue on that tangent?

Dr. Seiler: Yeah, well, I got on that tangent because you told me about your background with electrical engineering and stuff like that. So you obviously have – your’re technology savvy, and that’s kind of the whole development. We’re in this rapid ramping up. I was in the lab today with an athlete from a professional cycling team, and these new kids, these 19 year olds today, they’re used to starting every workout by pushing several buttons to start their various devices that now capture power, capture heart rate. He was wearing a shirt that captures ventilation, a wearable that we’re working with and we’re measuring Lactate. And so that’s just where we are today. But it’s just like an F 18 fighter pilot or whatever, the newest F 35 I don’t know, whatever the newest thing is. But anyway, they’re going fast, and they need to keep their eyes on the prize, right? But they also need to have some data. So what do they have? They have a heads up display, which raises the key variables and key numbers up to where they can keep their eyes looking forward, but see the data. And that’s kind of what we need for sports, for athletes, for coaches, is we kind of want to say, all right, out of all these different variables that are on the console, what matters in the heat of the moment from day to day? And then try to give them good access to those numbers in an understandable way so that they can make those basic day to day decisions about the training process. Do I train as planned? Do I adjust? Do I take a rest day? It comes down to some basic decisions, but it’s built up around a bunch of data that you kind of have to kind of have a gestalt feeling about, right? Well, it’s heart rate is a little low, but heart rate variability says this, and Lactate says this, and his perceived exertion was this. The coach still has to have a bit of an artistic or the feeling in German, I think it’s called [German]. You look at the athlete, you look in their eyes, and you can feel whether they’re ready or they’re tired. You know what I mean? When it comes down to it, it’s still tacit knowledge, if you know what I mean by that term? Good coaches have something we call tacit knowledge. It’s just they don’t always know how they know, but they can see how their athletes move, and they can look at their athletes expressions. They can hear what they’re saying, and they make good decisions. So with all the technology, there’s still an importance or a value to just that… what’s up inside the head of good coaches, I think..

Sonya: And also just the athlete to understand their body and how they feel, because with all this data, it can really throw you off. And I’ll share a funny story. I don’t know if it’s funny or not, but I just did my first mountain bike race back in three years because I had two kids in the last three years, and the Pandemic, the Canadian border, was closed, so I couldn’t race. So my first race back was 100 miles mountain bike race in Oregon, and it was at a moderate altitude. And I live at sea level. And I wear a Whoop device, and I think that Whoop is a bit over. Like, people over index on what it means, and they put way too much faith in what the Whoop says, and they don’t listen to their own body. So for people listening, I woke up in the morning of the race, the day before the race, I’m just learning how to manage…I have a four month old baby and a two year old. I’m, like managing my pre race prep, and it’s just completely not what it used to be. And my Whoop score was 1% recovery, and I have never seen that in my entire, like, I’ve been wearing for years. I was like, 1%? Yeah, I am the worst I could possibly be. And someone could look at this Whoop score and they’re going into 100-mile mountain bike race and think, well, I shouldn’t even line up for the race or they think I’m going to feel terrible. And that becomes the reality, is that you do feel terrible because you think you’re going to feel terrible. So I’ve had lots of days where it told me that I was going to feel really good and I didn’t. And lots of days where I felt terrible or vice versa where it said I was going to feel good terrible, and I felt really good. So I went out to the race with my 1% Whoop score, and I felt fine. Aside from going a little bit too hard for the altitude that I was at, re-learning about how to race my bike, the data that I’m just long story long, is that I think we put too much trust in what some of these algorithms tell us about the actual data.

Dr. Seiler: You are on to something really important. Just because you throw numbers at us doesn’t mean those numbers are useful. And I don’t want to be negative to any specific product but I think Whoop is very typical for the field in that they land on a few things that you can measure like heart rate variability and then they try to stretch it out and create lots of other rings around that core measurement. But with each ring the validity just keeps going down, down, down. Right. And so you’re trying to market a product that’s going to tell you about your sleep and how you’re doing with your boyfriend and all this stuff. It can’t. And unfortunately that’s part of the technology development is that yes, there are some good technologies, but there are also some technologies that are not mature enough yet. But they’re being pushed and they are creating perhaps just as much confusion as they are creating clarity. Yeah, that’s part of the challenge.

Sonya: I think personally with the Whoop just saying on this tangent is that for me, I know that the numbers aren’t the absolute numbers and they might not even be that accurate. But I noticed that if I am wearing it, it reminds me that I should be prioritizing my sleep. It just reminds me of the habits that I want to have. And while the numbers might not be the exact thing or the algorithm might not be right, it still helps me stay on track with the habits that I want to promote.

Dr. Seiler: Yeah, and that can be worth a whole lot. So should I say, we shouldn’t see around or not respect that reality which is just helping athletes tune in mentally to certain things. Like for example, just like you say, I’m using a wearable technology to measure ventilation because we’ve never been able to measure ventilation outside the laboratory in a valid way. Every athlete knows that breathing tells you a lot. You can hear the fatigue of the other athletes in their breathing when you come up beside them. You feel it in yourself when you start you get to your limit. So it’s an interesting tool but just measuring it also makes me think about it and makes me think about not going [breathing hard], learning to try to get bigger tidal volume to use my lungs better when it’s starting to really get nasty. Again, I wouldn’t say placebo effect, but it’s focusing me on thinking, you know, breathing matters. When you’re starting to really struggle, you have a tendency for your breathing to get a bit jerky and you’re not breathing in a very effective way. So just measuring it has tuned me into those things. So there is value just to that, even if the numbers are not perfect. I agree with you there, but I would like the numbers to also be really good.

Sonya: It sounds like respiratory training is something that’s really interesting you right now.

Dr. Seiler: Well, actually not so much. I’m not so sure that we need to train the respiratory muscles. I think they’re probably… that’s not the limiting factor. But what I’m really interested in in this breathing issue is, number one, it captures some aspects of stress during workouts that heart rate doesn’t. So it’s a complimentary, t’s a vital sign. I’ve said to other people that if you go into the hospital and you’re unconscious and they wheel you in, what are they going to do? They’re going to measure your heart rate and they’re going to measure breathing. Those are the first two things they’ll do because those are the vital signs. Right? And now I got the air quotes going. But we’ve always just had heart rate for the last four or five decades in the field for sports. I think now being able to move breathing over into the field will be a useful tool, but we’re working on it now. What I was going to say is one of the things I found is that this notion or this idea of breathing, of just nose breathing, where you just close your mouth and breathe just through the nasal passages. Wow, that is really almost meditative. And I think it’s good for my sinuses. I think it may even help, I think research needs to be done on this, but with using nose breathing during training, it might translate to better sleep if you sleep with less mouth breathing, because a lot of people open, they get sleep apnea and all these different things. So that’s one of the things we’re looking at, is just that. It turns out that the nasal passages, they were designed to warm up the air and filter it and do a lot of things. It doesn’t happen when you breathe through your mouth. So I’ve gotten where I can do three, four hour rides just breathing through my nose. Now I have a big nose, don’t make fun of me, but I don’t think that’s the only reason. I think it’s trainable. I think we can get better at it, and I think it’s probably good for our health. There’s data that shows you have less risk of infections and a lot of different things. So anyway, I think breathing is one of the frontiers that we’re exploring and trying to move out of the laboratory. That’s the big thing. It’s no longer just a laboratory measurement. And that’s true for a lot of stuff. And it’s kind of that technology we were talking about. You’re a cyclist. You know, the cyclists have just basically said, well, we don’t go to the lab anymore because they don’t feel like they need to. They have power, they have lactate, they feel like they have a lot of data without going into lab.

Sonya: Yeah, as a cyclist, though, I’ll say that and, kind of a nerd, I like being able to control as much as I can whenever I’m doing an experiment on myself. So if you’re in the same environment, on the same trainer trying to measure something, it’s easier to see if something has improved or if something that you’re doing is changing something versus if you’re going outside the variables are really hard to hold. Like you can’t hold as many things constant. So I actually like the idea of the lab for trying to see if something’s working or not.

Dr. Seiler: Yeah, and here’s the deal. I was having this discussion because I’m like you, I was raised in that lab world. I was trained there. And that’s what we do. We’re reductionist, we control everything. And we tell them that no caffeine and no this and know that, and no hard training the day before. And we create all these conditions and it actually becomes kind of artificial because in the daily grind, they are using caffeine and they aren’t always sleeping and they are training every day. So they’re somewhat fatigued from day to day. So that’s the reality. So lab is one off and we get one measurement. We maybe get them in the lab two or three times a year. But nowadays we can collect data on their power and their heart rate every day, every darn day. And so we can paint a mosaic of data. And yes, there’s noise from day to day, but when you’re getting the data every day, then the variability smooths out. Are you with me? And so we can construct things like power duration curves and so forth that actually end up being quite strong. They’re robust because now we’re getting so much data, we’re overcoming the one-off problem. So even though from day to day, yes, there’s some noise, we overcome it with lots of data points. There are two ways to get at this. And I agree with you that a little bit of both is probably nice. That’s why I have a cycling room upstairs. It’s almost like my lab, because, yeah, I can control things really well. But I also know that real cycling happens out in the real world. So those realities also need to be part of the mix.

Sonya: And this sort of brings us back to the conundrum that we started with of so much data. How do you know what data you should pay attention to and how do you optimize and how do you understand how to go off of field? Because I think what you’re talking about a little bit is that a lot of us didn’t get enough sleep the night before. It’s not an ideal environment whenever we go out to do our workout and to understand how hard you should go in that workout, if you’re going off of what you think your FTP is. That number is going to be different every single day depending on how you’re feeling. So how do you actually learn how to go off of feel but also look at the data and make good decisions?

Dr. Seiler: Yes, and I think that’s one of the things that distinguishes champions. In our work, we’ve had the luxury of being able to measure a lot of Olympic gold medalists and so forth. And one of the things that distinguishes them is, number one, they have what I call intensity discipline. They plan to work and work the plan. So if today’s plan is a three hour easy ride, then they keep it easy. And they’re not going to let some showboat that cycles by them that says, ah hah, I just went by the gold medalist, they don’t care because they know what they’re good for. So that’s one thing is intensity discipline, but the other thing they do is they triangulate. In triangulation, us science folks, we like triangulation, meaning that we use two or three different methodologies. So what I want to help my athletes do is calibrate their perception with some numbers. So what are we measuring? Well, in cycling we can measure power, so we can measure what we call that external load. And we can measure the internal load, which is some physiology through heart rate, through ventilation, through blood lactate. And then we can measure perception. We can use metrics like perceived exertion, the rating of perceived exertion, or we can do it more qualitatively, just how did you feel? But that triangle then gives us a kind of a checks and balances system, like a well functioning government, which not all countries have anymore. But the idea is that the different bodies of the government kind of service checks and balances around and keep things from getting distorted. Well, that’s how triangulation works with monitoring as well. And so I think athletes… one of my colleagues used to measure blood lactate. He worked with the national rowing team in Norway, and he said those guys, he would take a lactate, they would be at altitude camps, they’d be doing some workout. And he used the lactate monitor. And it feels like it was about 3.2. Well, it was 3.3. They were just so close. They were so calibrated. And I think that’s part of the job of being a high performance athlete is you got to be tuned in. You have to be able to really feel what’s going on in your body and make these decisions about how far do I stretch that rubber band on this workout today and when do I call it quits? And then the other thing is, they’re thinking big picture. You’ve been a high performance athlete, and you know that a training year consists of hundreds of workouts. I don’t know what your number was, but maybe you trained 500 times a year. Were you training double workouts a day on some days?

Sonya: Not usually. I was doing a bit of running last year, so I was doing doubles when I was running. But no, I train usually just six days a week and one workout a day.

Dr. Seiler: Okay. Yeah. And cyclists, they tend to do single workouts, but they’re longer. But at any rate, there’s a number. Like last year, my number was 314. I did 314 workouts. That’s about six days a week. And I was very pleased with that because that was kind of my goal. I managed to stay healthy. And so that’s a lot of workouts. And if you start talking about the effect of any one workout on performance, it’s very tiny. It’s not even measurable in the noise. But yet when you add it all together and you have a good training season, good things tend to happen, right? And so that’s what the elite performers understand, is it’s not the epic workout that wins medals. It’s the consistency, the continuity, staying healthy, knowing when to back off 10% so that you’re able to fight the next day. Sometimes you got to lose the battle to win the war in the sense that you make small adjustments and you back off sometimes in order to be able to sustain that high training load over time.

Sonya: Yeah, I could not agree more. I talk about that a lot. Consistency and then consistency over heroic efforts, because one heroic effort is just a data point and it could be an outlier and not the norm.

Dr. Seiler: Yeah, and it could bury you for three days. And so when you look back, you ended up training less in total because that epic workout just busted you. And so we don’t always think about that reality.

Sonya: So a lot of people listening to this are not, quote, high performance. Like they’re not racing at the top level, they’re not professionals. And they’re probably thinking, well, how do I know how I feel? And my husband’s asked me this so many times because I know exactly how I feel and what I need to be doing most of the time. But he’s like, well, how do you know that? How do you figure that out? So how does somebody begin to understand what that is supposed to feel like?

Dr. Seiler: Yeah, that’s a great question. It’s like asking a piano player, how do you know when the notes are right? There is something about doing it many times in both experiencing flow, where we’ve all done really hard workouts, let’s say an interval session, but you were in a state of flow. I mean, you were just on the ragged edge, but you were in control. And you get an experience for what that feels like, that it’s a kind of a pacing problem, right? Even workouts have pacing aspects to it. And so, like you say, okay, today I’m going to do five times eight minutes at some goal power or roughly. And you kind of know after the first eight minute bout what it’s going to feel like, the progression, right? You can extrapolate mentally. There’s a term for this. It’s called teleoanticipation. Our brains can take our present perceptual data about how hard is this feeling and so forth, and then say, okay, now I’m projecting the rate of fatigue to try to decide, am I going to get across the finish line at this pace? Right? And it’s remarkable that, not just high performance athletes, but anybody that practices a bit, you pretty quickly find the right pace. If I say go out, run 10 km as fast as you can, within about half a kilometer, a kilometer, you’re zeroed in on what you think is going to be your pace.

Sonya: Or you might be so blown up from starting too hard that you’re paying.

Dr. Seiler: Yeah. So you’re not going to make the mistake of sprinting the first 200 meters more than about one time before you understand that you’ve got to project things forward so the brain is capable of doing it. And athletes tap into that perception, but it also is something they do in workouts and so forth. And over time, they learn a bit about, I think we learn about this idea of holding back, retreating from the battle to win the war, that you can’t go out every day and go full gas, you can’t go hard every day. That’s a lot of what my research has been about is about this idea of polarized or 8020, and that athletes have figured this out. And it’s not just high performance athletes. It works for regular people, training seven hours a week, eight hours a week, 10 hours a week. Like me, man, we have so much to gain by getting this kind of intensity distribution reasonably right. We recover better, we get better progress, we enjoy training more. And it’s amazing how often people talk and say, you know what, I’m running faster than I have in years, and I feel like I’m training easier. It’s quite interesting to hear that from people, but that’s a very common response I get. They say, you know, it took me a while to figure this out, but you’re right, keeping my easy sessions easy. I feel good when I do the hard sessions and I PR’ed the last my last 10K or something. So it works not just for the high performance athletes. It scales down, this idea.

Sonya: Yeah. Can you go more into your model of periodization? Because I still think that a lot of people have heard of it, but they still don’t actually do it. And I ride easy a lot too, and I see people just going hard every single day, or people like, hey, let’s go for a ride. And they’re just like, hammering as hard as they can, and it’s like, we’re just supposed to be riding. Or even this race… I did this race in Columbia in 2017, and it was a stage race, and it was the day before the race. It was supposed to be just like an easy ride, and everyone was just going so hard, and I was the only one that dropped out. I just was like, I’m not doing this. I turned around and went home. And that’s hard to do. A lot of people will feel like, oh, I’m not good enough, or there’s a psychology piece to being brave enough and having the confidence to go easy when you need to go easy.

Dr. Seiler: You are so right. Like I said, man, that is what distinguishes champions is that self confidence, to say they know what they’re good for. They know that, dude, bro, come back tomorrow. Some guy runs past them or cycles past them, it’s often guys, so I’m using guys as an example because they’re just guys tend to just compete and everything. And so they start half wigging each other. And the really good ones, they’ll just let them go because they know that in their mind, they’re thinking, tomorrow I’ve got a hill session. I’m going to be doing 20 minute repeats on this tough vertical, and these guys are welcome to come back tomorrow and ride with me, and we’ll see about who’s boss. But they just don’t invest their ego in this kind of stuff because they’re playing at a different level. Right, but that takes time to be secure in yourself. I mean, good grief, I’m the same on Swift. Someone rides, pass me, my first instinct is, “what? You ain’t doing that.” But then I try to remember what I preach, and so I try to be smart. At least a fair number, a fair percentage of the time I’m able to pull it off. But that is kind of at the heart of development for athletes, is thinking, what is my plan for me today? Work my plan and don’t let other people’s craziness mess me up. Yeah, because if I know they’re going too hard because they’re racing in two days, well, just let them go because you don’t get any medals for winning the workout. You win the race. So that’s part of the deal, is knowing when you’re going to empty the tank, and you don’t empty the tank on an easy pre race workout. Right? You would think the things we’re saying here are obvious, but they go against our kind of instincts because we’re competitive people. The non-competitive people, the people that go out and run just for the joy of it, they don’t have the same problem. But all of us Type A competitive people, we’re the ones that have to figure out how to trick our brains and find ways to distract and listen to a podcast or do whatever we can during an indoor ride like I do, to keep calm. Just say no, just keep it down. Let them go. Listen to your podcast, keep your 200 watts. And so I think that’s kind of part of the Zen of training that you have to learn through some hard knocks.

Sonya: Yeah, just hearing if you describe that experience, I feel like my body tightening up because I want to start just like, hammering, too. And that experience, it just never goes away. Like, even if you have been doing endurance sports your entire life, even if you’re a foremost researcher on the topic, even if you’re insanely competitive, you just still don’t like it when somebody passes you, no matter what. But you have to look and say, what is my plan? And like you said, find a way to calm yourself because it’s hard when someone like, I actually get very angry when people pass me, and I’ve actually heard myself cussing under my breath at them because I’m so just like but I have to keep that in check. And it’s funny, it’s funny to see the competitive drive come out and then to understand that we have to have the discipline to not blow it at that moment.

Dr. Seiler: Yeah, like, I was riding on Swift a couple of years ago, and it was like a Saturday morning ride. And all of a sudden I realized, hey, I’m riding with Cadel Evans, former Tour de France winner. You know, now he’s retired, he’s in his 40s, and I’m in my 50s, and I’m thinking, I’m keeping up with Cadel Evans. And at some point he had to go do something with a kid or pee or something. And then that’s when we understood, okay, he’s still so much better than we are because he just time trial’ed back to us, right? At six watts per kg or whatever. Okay, you’re still the dude, you’re the boss. But when he was riding for, I think it was Oracle Green Edge, a colleague of mine was telling me about, they’re on a training camp early in the season. I mean, it’s like January and they’re at some altitude camp, and they’re going to do some climbing. And the young guys are like, why is he not going harder? Because they didn’t feel like he was going that hard. And they said, well, I’m not going to ask him. You ask him. No, I’m not going to ask him. It’s Cadel Evans. And so finally, one of these youngsters went over and asked, mate, you’re the best in the world, but you don’t seem to be pushing these interval sessions, these climbs very hard. And he says, well, mate, it’s a long season and it’s January and I’ve got to pace myself. I’m going to be at my best in July. And so he was basically telling the guys, you can’t turn every workout into a race, or you’re not going to be where you want to be when it matters. That was that wisdom of the experienced athlete that is thinking, he’s not only pacing, or she’s not only pacing her workouts or her time trials, but you pace your training. Does that make sense?

Sonya: Absolutely.

Dr. Seiler: You’re pacing the whole training process from day to day, week to week, and month on month, so that it is sustainable. I know that word is overused and worn out, but it is an appropriate concept for athletes to embrace that if the training process is not sustainable, then the goals that they have will not be attainable. And you have to live through that. That’s successful training. When you ask athletes, was this a good training year for you? They don’t talk about epic workouts. They talk about, yeah, I stayed healthy, I had very few injuries, I had great continuity. I accomplished about 97% of my planned workouts. That’s how they measure the success of the season, not the one epic workout where they did 20 times 400 meters on the track, you know what I’m saying? So I think we can learn from that.

Sonya: Yeah, that goes back to that champion mindset that you’re talking about. You mentioned thinking big picture. So for the listener who isn’t familiar with periodization, who isn’t familiar with 80/20, who isn’t even familiar with training in different zones, can you give kind of a layman’s overview of what that means and the research that you’ve I know you’ve done a lot of research, so it’s hard to summarize it, but can you try to do that for the person who’s not familiar?

Dr. Seiler: Well, the bottom line is, when you measure the best, what you find is that they can’t go hard every day and they figure that out and in fact. They go as a rule of thumb, that’s where this 80/20 comes from. Is that maybe eight out of every 10 training sessions they do, and they obviously train a lot, eight out of every 10 will be for them a pace that is comfortable. It’s manageable. It’s talking pace. It’s a pace that they can actually be talking to the person beside them. They can be enjoying the scenery, you know, they can be distracted a bit by the external environment. So it’s enjoyable. Now, let’s face it, they’re doing this a lot of hours. So a lot of us wouldn’t be able to stay at the intensity, even those easy intensities, for as long as they can. But they’re accumulating a lot of time at a sustainable, comfortable pace. And then they have maybe 20% of those training sessions. They’re tough, they’re intense, and they’re long and they’re hard and often race pace or close. So that’s that polarized model that we’ve seen is quite a lot of low intensity, some high intensity, and then managing that balance. Why? Well, it’s because it seems to be because, number one, the low intensity sessions work. They do create adaptations in the body, but they work mostly through duration. So intensity is a bit lower, but duration is a lot longer. So we still get a great signal for adaptation. Build mitochondria, build capillaries, improve heart function, all of these things. But the recovery time is shorter. I often talk about that most of the workouts you do as an endurance athlete, you need to recover from in 24 hours. Why? Well, because if you want to train basically daily, then that’s the clock, right? The clocks at the end of every workout now the recovery clock starts and it needs to tick down to full recovery or reasonably full recovery in 24 hours. If every workout is taking longer than 24 hours to recover from, then what happens? Well, if you’re training every day, then you’re going to slowly fall apart, right? So these easy sessions allow recovery. They keep below the stress radar and then occasionally, or regularly, but a couple of times a week, for example, we’re going to do those harder sessions where now it’s going to take maybe 48 hours to recover, even 72 if it’s a really tough workout. But we’ve created room for that in the plan. Does that make sense?

Sonya: Something that I wanted to bring up was going back to algorithms and data and numbers. I just started using a Garmin. I was using a Wahoo for a number of years. And just for fun, just seeing what these different computers do. And I noticed that the Garmin will say, it’s going to take you this many hours to recover, or like, you’re acclimated to this number after one workout. How do people take that data? Because a lot of people don’t have a coach and they don’t know themselves how to understand that data. So how can somebody sort of extrapolate what’s best for them based on that?

Dr. Seiler: Yeah, I guess my first thought is guys and gals take all of those numbers with a big grain of salt because let’s face it, and I work with companies and I understand they’re trying to sell a product, but let’s take a HeartWatch. I’ve got one on here, and it has the optical sensor, so it’s got the little green lights that flash. And this company that makes this watch, the most profitable way for them to work is to have one piece of hardware and then lots of algorithms connected to the one piece of hardware because then production costs are lower. Right? If they can start eliminating external stuff like belts and all this stuff and just have the one device, well, that’s a better business model. And then you attach lots of algorithms to that hardware. And those algorithms are soft, they’re fuzzy. And they’re trying to tell us that they can measure our caloric consumption, they can measure our sleep, they can measure our recovery and different things. But like I was saying earlier, it gets just fuzzier and fuzzier the farther you go away from the core technology that device is designed to do. And what’s that? Measure heart rate. That’s it. Everything else makes lots of assumptions and plugs in lots of algorithms and it becomes a bit of a black box. So just keep that in mind when you’re using these things is the farther you go away from what its core function measure heart rate, right, and they can do that potentially well. But for every step outside of that box, be more and more suspicious and less and less confident in those numbers when it tells you your VO2 max is 62 and your favorite color is green based on our data. Come on. This is marketing, unfortunately.

Sonya: So you talked about the 80/20 rule and how it’s important to keep your easy days easy and then on your hard days you want to really dig in and go hard. But a mistake that most people make is that they go moderate all the time. They’re easy isn’t easy enough, and the hard isn’t hard enough. So how can somebody know where they’re supposed to be?

Dr. Seiler: Well, all right, of course, in a lab, we can measure lactate. We can do tons of things and establish these various thresholds. But for the average person that doesn’t do all that stuff, easy should feel enjoyable. Literally, that you should actually be able to think, I’m kind of enjoying this. I’m not suffering, amazingly enough, and I can, actually like I was saying, some indicators, some poor person’s indicators that you’re in the right zone when you’re doing that easy session, that low intensity session. I don’t like the word easy because it suggests that we’re lazy. It’s purposeful; it’s intentional, but it’s based on finding the right balance between intensity and duration. So we’re stretching in the duration direction. And so what I tell people is, number one, that, again, talking pace, that you should be able to be distracted. You should be able to hold that watt count or that pace without having to really concentrate. Right? Because one of the things that happens there’s almost like this threshold, I would call it the concentration threshold, where at low intensity, you can divert brain function to other thoughts besides holding the pace or the power. Does that make sense? You can be talking about whatever. You can be looking, oh, wow, the flowers are blooming here. That’s kind of fun. Did you smell that? That didn’t smell good. Did we just go by a farm? And say you’re thinking about lots of stuff and the brain is able to do that because you haven’t passed that concentration threshold. But then once you get to a certain intensity where it gets pretty tough, now you start to have to zoom inward. You start to have to monitor everything. You’re starting to feel how my legs feel? How’s my breathing? Your brain is scanning. You know what I mean? It’s almost like the brain goes into scanning, and it is scanning all the systems and making evaluations. Can we hold this power? Is this okay? I’m right on the edge, right? Well, then we’ve gone into that high intensity or that hard session type of mentality. Well, you can’t do that every day, right? It’s mentally exhausting. So that’s one of the distinguishing things is that you should feel comfortable, be distracted. We don’t usually listen to music when we’re cycling because it’s dangerous, but it would be the kind of thing you could do. You’re chilling and you’re in the zone, you’re smooth. And the other thing you will often feel is that after those low intensity sessions, maybe it’s two hours on the bike, maybe it’s a 75 minute run. You can come straight in and basically go straight to the dinner table. Your appetite is there because you’re kind of empty. Those workouts make you feel empty versus high intensity workouts you feel poisoned in a way. You know what I mean? In a way, you are, because you’ve built up a lot of metabolic waste products that actually feel like almost toxic. You’re exhausted, and it takes time before your appetite comes back because blood flow has moved away from the gut and out. And so it takes longer for your body to kind of re-equilibrate so that you can even think about eating. So that’s another kind of a poor person’s threshold where you can feel, did I stay on that side of that low intensity side, that low stress side, because we’re trying to avoid triggering that big stress response during those low intensity sessions. Does that make any sense to you?

Sonya: For sure.

Dr. Seiler: So those things you can feel without even measuring heart rate, but then after a while, you can also start to see, okay, in this heart rate area, this is good for me. And another thing that I can tell you, if you wear a heart rate monitor and if it’s a good one and it works, you get good measurement, then the other thing I would say to people is if you are doing that low intensity session where the goal is just to be down in that fat burning intensity and steady heart rate should come up at first, but by about 15 minutes into the workout, it should flatten out. And it should stay flat. It shouldn’t just keep going up, up. Okay, if it is going up, up the whole workout, you’re working too hard. Either that or it’s 105 degrees Fahrenheit and you’re training in extreme heat, and you just cooked. That’ll also do it to you. I say that because I think probably a lot of people are experiencing some tough outdoor conditions, so I have to say that. But under normal circumstances, we should be able to keep that heart rate flat, drink, stay ventilated, and so forth, and heart rate shouldn’t just drift up. Now, if you go long enough, it will start to drift up, but at least for 90 minutes, for 75 minute run or something, it should be pretty darn flat.

Sonya: What about when you can’t get your heart rate up?

Dr. Seiler: There you go. Usually what that means is you’re tired. It means the brakes are on. The autonomic nervous system is telling us it is strained. And so this is a really important thing you bring up because there’s two ways things can go. There are days where your heart rate may feel it’ll be too high. Maybe you did a tough strength training session and your legs are sore and that you go out the next day and your heart rate’s too high. It’s 10 beats higher than normal. And that makes kind of sense. But what’s trickier are those days where you’ve been doing some pretty good volume or you’ve had a couple of races on the weekend. And then all of a sudden you go out to work out and your heart rate is ten beats lower than normal at a given pace or power. Now then you got to do something with that information. And the instinct will often be what, oh, I must be in shape, I got to go harder, right? My heart rate is low, I got to add 25 watts. That’s the death spiral, okay? Because that heart rate is lower because you’re tired, your body is fatigued. The entire autonomic nervous system, that sympathetic side, that fight or flight side, the brakes are on. The body is trying to say, tell you, slow down. And if you fight that and misinterpret the signals, then things get even worse. And that’s where we get into those overreaching, and in worst case scenario, overtraining situations, that can be quite… can lead to a long term decline in performance. So when we feel that the brakes are on, how do you solve it? Rest. That is the only way is you got to give your body ease off, easy workouts, rest day. And while we’re on the topic, rest days are not sinful. They’re not a sign of weakness. They are critical to long term performance is having confidence enough to take a rest day when you need it. I mean, full on rest day. Does that make… you know what I’m saying?

Sonya: I actually love rest days.

Dr. Seiler: Yeah. I mean, good grief. Also, if you’re a normal person with a job and kids and everything, then rest days are when you get, pardon my French, but that’s when you get shit done. Because now you’ve saved two or three hours because you’re not training that day. And you can actually reduce your stress, your total stress, because you say, now I can get the bills paid. I can do some extra stuff because I freed up some time. This is my rest day. It’s both physically you’re recovering, but also often psychologically, it just frees up a bit of time for people who have multiple issues to deal with that’s life, right? Not everyone is a pro athlete that is just eat, sleep, repeat, eat, sleep, train, repeat. That’s not the normal situation for most of us. So I like my rest. I like Mondays often a day where I’m not doing much hard training and it feels great.

Sonya: I’m actually going to argue a little bit about the rest day now because this is something I’ve had to learn the hard way. I’ve been a professional athlete for a long time, but I have a very difficult time doing the sleeping, riding, and…I have to have other things going on for myself because I just really like that mental stimulation. So on your rest days, if there’s too much mental stimulation, I learned that I can actually increase physical fatigue. And then I started looking into how mental fatigue impacts physical performance. And there is a detriment if you’re working your brain too hard.

Dr. Seiler: I lost you.

Sonya: You hear what I said?

Dr. Seiler: Now it’s saying the connection is unstable, but I think you’re back. So I lost the last sentence you said.

Sonya: The last sentence is that too much mental fatigue can impact your physical performance. So on your rest day, if you’re doing way too much stuff, I’m going to do way more mental things than I was doing. Yeah, that’s not enough rest. So it’s hard to figure out for yourself on your rest day. It’s not realistic for any of us to just sit around and do nothing all day on our Monday because we have to work or kids or whatever. But not overdoing the tasks on your rest day, too.

Dr. Seiler: No, I agree with you. And that’s a good corrective on what I said. It’s not like you want to just load up the rest day with so much stuff that it becomes a marathon in itself. So I totally agree. And you’re right. There’s research that shows, for example, university scholarship athletes during their exam periods, those periods, they respond poorly to training. They literally because the brain is stressed, there’s brain body connections that we don’t all understand, hormonal and otherwise, that change the atmosphere of the body and reduce the adaptive response. So when athletes are stressed by other stuff, academic stress, work relationship stress, or so forth, it can directly impact how they respond to training. Our evolutionary bodies, our evolutionary systems are not that they don’t distinguish this idea of stress. It’s kind of one bucket for the body and the brain. The total stress load, it can be coming from many directions, but it’s not just the physical training. It’s everything else. It’s the anxiety of fear of getting infections. All these different things are hitting us. And so that’s a really worthwhile point to keep in mind and just be cognizant of it. Good coaches, for example, I’ve talked to some and they say, yeah, my university coach, my rowing coach, when we had exam periods, he just reduced the training load with two sessions a week. He cut out two sessions a week just to try to create more room because he knew that we couldn’t handle, that we were struggling. So that was a proactive or prophylactic training load reduction.

Sonya: That’s such a great nugget for people to take away. There’s one bucket labeled stress, and your body doesn’t care or differentiate between all the different things that you’re doing. Once that bucket is full, that bucket is full. So you might need to reduce input so that bucket doesn’t overfill.

Dr. Seiler: Yeah, there’s a guy named Marco Altini. I’m not trying to sell a product, but he has this heart rate variability,, and where you can measure heart rate variability just using the phone and the light, you put your finger on the camera and it works really well, validated. He’s presented such great data from thousands and thousands of people and he just can show how heart rate variability, which is an indication of parasympathetic sympathetic balance, how it goes down in just population wise when these things like the pandemic hit, just stressors that you can just see a population-wide change in heart rate variability. So it’s quite fascinating. Like you say, it’s this one bucket reality that we’ve been through a two to three year period with a lot of anxiety. There’s enough anxiety to go around always, but this last couple of years has been particularly full of angst for a lot of people, job security, many different aspects to it. So this has been a part of the reality and I think it’s affected the training of a lot of people. Some people have been able to train better than usual because they’ve been isolated, they’re working from home and everything. But a lot of people found that it was really tough to come through. And now we’re finally, hopefully getting on the other side of a lot of that. But it’s a little unclear, it seems where COVID is going to be around for a while.

Sonya: Yeah. Thanks for bringing up HRV, because I think that has been something that most people now sort of have either come into contact with or understand or measure regularly. And how that is something that people can look at and see how different changes and inputs in their life can impact their HRV and what that means for them.

Dr. Seiler: But it’s like everything else, HRV is one of these things that if you need to measure it regularly, you need to do it basically daily so that you establish these baselines and you can interpret what’s going on. Well, if you do it just here and there and randomly, it’s not going to be useful to you. The people selling the products will tell you exactly the same thing. If they’re honest, they’ll say HRV can be a valuable tool, but the interpretation depends on you using it very regularly.

Sonya: And then there can also be just like artifacts. I actually believe that day, that race day that I was talking about when we first started, my HRV is normally like 100 or 90 and it was 30 on that day. And I think that could have been just a data… like the device wasn’t working properly because I’ve never seen that before. So being able to look at it that way and say, well, this actually might just be some noise and it might not actually be true.

Dr. Seiler: Well, yeah, this is where things get problematic because like, for example, this type of watch, which is very common, I’m not going to tell the brand, some might be able to tell, but it’s got the optical sensor. This is industry standard. It’s at the wrist and it sucks. They don’t work very well. I’m just telling you the truth. And this is based on athlete feedback. This sensor at the wrist, on a bony wrist, it easily gets light gaps. It easily moves around. It doesn’t get enough blood flow under. There’s not enough vascular tissue or vascularized tissue under the optical sensors. It’s just a terrible place to place this technology. So even just moving the wrist watch up here gives better heart rate data.

Sonya: And he’s showing his forearm, for those of you who can’t see it.

Dr. Seiler: Yeah, literally moving it up a couple of inches to a point that it says, well, that’s too high on my wrist. Yes, but for heart rate, it’s better. So that would be if you’re having trouble with your heart rate data and it’s noisy, and it’s just either one, get rid of that darn watch and go back to a heart rate belt or go over…either move the watch or buy one of these heart rate bands that go on the forearm or on the arm. They work great. I’ve used one for years. My daughter’s used one for years. And that optical sensor is exactly the same technology, but now it’s at a location on the body where you get nice blood flow under the sensor and you get better data. Now I’m getting all geeky and techy, but unfortunately, that optical sensor technology just doesn’t work. Very reliably for lots of people when it’s at the wrist. And then you can get bad data, you can get HRV artifacts and all these things that confuse the crap out of people.

Sonya: Yeah, you actually recommended to me, I think it was the Polar Verity Sense, and that’s not a sponsorship, anything, but I started using that because I was getting tired of using a chest strap, because I felt that over a long period of time, that actually restricts respiratory, and I would get soreness from wearing, like, a strap. I wore it up on my bicep, and I wear it underneath my jersey sleeve. And that’s been just way more reliable. It’s even worked better than chest straps that I’ve worn. So thanks for that recommendation.

Dr. Seiler: Yeah, like I said, I’m not selling anything, but this is just experience. And I’ve heard a lot of feedback to say the same thing as the Verity since before that, it was the Polar OH1, which is what I still use. It just works. And I mean, I get like one drop out a month, maybe. Literally one second of data that’s off once a month. It’s so nice and reliable. So I’m willing to give a plug for a technology that works well.

Sonya: There’s so much that we could have talked about. It was almost overwhelming trying to figure out what to bring up on the podcast today because you have so much expertise and our time is already up, but there’s so many different places people can find you. I don’t even know how hundreds of publications; I thought I saw like over 8000 citations on Google. There’s just so much you’ve done in your body of work.

Dr. Seiler: That’s the advantage of getting old. So it’s a marathon, but yeah, so people can find my stuff. I’m on Twitter, so it’s kind of a running dialogue going on there on Twitter. Just my name @StephenSeiler and I have a YouTube channel. It’s not something I do every day, but I do put out some videos on various topics and then the publications for those who want to actually read the research, one of the best outlets is called Research Gate. At least if you’re a student and you have an affiliation with a university or you’re in academia, then it’s very easy to get all that stuff for free. Most of my publications are available online for free via Research Gate.

Sonya: Well, thanks so much for coming on the show, and we’d love to have you back sometime.

Dr. Seiler: Sure. Good conversation. So thanks a lot.

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