We all know what fatigue feels like. It’s likely we’ve all experienced that exasperating feeling when our legs give out on a critical climb, or our sprint fails to materialize at the critical moment. But do you know what causes fatigue?
In this episode of Fast Talk, we’ll attempt to unlock the mysteries of fatigue. Is it just lactic acid pooling in your legs, as your high school coach probably told you? No, that’s not it. The answer is actually a lot more complex than you’d think. In fact, some of the most exciting theories have only recently been proposed. This episode reveals those exciting revelations and explores the foundations of fatigue.
First, we’ll discuss the many different physiological causes of fatigue, including muscle damage, glycogen depletion, body temperature, and why no one of these reasons fully explains fatigue, despite what some researchers might tell you.
We’ll discuss an exciting new theory that suggests there’s a “central regulator” of fatigue, which integrates all of the different past theories and ultimately allows our mind to decide where our limits are. That is, could fatigue be, in part, a psychological thing.
We ask the question, how much fatigue is actually a conscious choice that can be influenced by the length of the race, cues we give ourselves, and mental tricks.
And finally, we’ll examine why we need to be careful about toying with our fatigue limits.
Our guests include Dr. Stephen Cheung, an exercise physiologist and professor in the kinesiology department at Brock University in St. Catherine’s, Ontario, whose research interests include the effects of environmental stress on human physiology and performance. We’ll also hear from talented climber Sepp Kuss, a neo-pro with LottoNL-Jumbo, who will talk about his limits when racing.
Primary Guest
Stephen Cheung, exercise physiologist & professor, Brock University
Secondary Guest
Sepp Kuss, pro with Jumbo-Visma
Episode Transcript
00:00
Welcome to Fast Talk the velonews podcast and everything you need to know to write letterpress.
Chris Case 00:10
Hello, everyone, welcome to Fast Talk. I’m Chris case managing editor of velonews joined as always by our resident training expert, Coach Trevor Connor. And today’s episode will attempt to unlock the mysteries of fatigue. We all know what it feels like. It’s likely we’ve all experienced that exasperating feeling when our legs give out on a critical climb, or sprint fails to materialize at the critical moment. But do you know what causes that fatigue? Is it just lactic acid pooling in your legs as your high school coach probably told you? No, that’s not it? The answer is a lot more complex than you’d think. In fact, some of the most exciting theories have only recently been proposed. Today we’ll talk about those exciting revelations and the foundations of fatigue including, number one the many different physiological causes of fatigue, including muscle damage, glycogen depletion, body temperature, and why no one of these reasons fully explains fatigue, despite what some researchers might tell you. Number two, a new exciting theory that suggests there’s a so called central regulator of fatigue which integrates all the different past theories, and ultimately allows our mind to decide where our limits are. That is, could fatigue be a psychological thing. Number three, how much fatigue is actually a conscious choice that can be influenced by the length of the race cues we give ourselves and mental tricks. And finally, why we need to be careful about toying with our limits of fatigue. Our guest today is Dr. Steven Chung, an exercise physiologist and professor in the kinesiology department at Brock University in St. catharines, Ontario, whose research interests include the effects of environmental stress on human physiology and performance. We’ll also hear from professional racer, Sep coos Neo Pro with lotto nL yumbo on the World Tour, who will talk about his limits when racing. So pay attention. Wake up, stop dozing off, and let’s make you fast.
Chris Case 02:34
Hey, Trevor, been for any bike rides lately?
Trevor Connor 02:37
I just did a whole training camp this weekend. Oh, wow.
Chris Case 02:40
How many miles?
Trevor Connor 02:42
Oh, boy. So it was 24 hours in the mountains of Boulder. So probably 80 miles.
Chris Case 02:50
is you’re feeling healthy?
Trevor Connor 02:51
I’m feeling pretty tired. Yeah,
Chris Case 02:53
good, good. Well, you know, for active people, like yourself, for listeners of Fast Talk, podcast, runners, triathletes out there, there’s a great product called health IQ that we are sponsored by today. And we want to tell you about their website, www dot health iq.com slash velonews. Where you can go as a listener of Fast Talk and get yourself a free quote. For healthy people. You go there, upload Strava records, mapmyride account recordings of your ride, and any other proof that you are indeed a healthy fit person. And you’ll get yourself a better quote. Pretty cool.
Trevor Connor 03:42
So Steven, welcome to the podcast. Obviously, you you work at Brock University, and you have a huge list of research publications that you put out while you’re there. But you actually are very heavily involved in the cycling world. And a lot of people might not know just how much you’ve done. So why don’t you before we launch into this podcast, just tell us a few of the ways you’ve been involved in including I believe you just published a book, correct?
04:07
Well, thanks for having me. And yes, you’re absolutely correct that we just published a book called cycling science. And it’s pretty self explanatory what the book is all about, but it’s co edited by myself and Dr. Michael zabala, who is a scientist at the University of Granada in Spain, and also the lead sports scientist for the mobistar protein. So that came out this late summer and it’s really about 40 different chapters, really an encyclopedia on many, many different topics in science of cycling, everything from physiology to bike fit, aerodynamics, pacing strategies, nutrition, environmental stressors, and power training, data management, so really a whole host of different topics. So it was really a labor of love and We’re really happy to have it out. All right,
Chris Case 05:03
so on to today’s topic of fatigue. Dr. Chung, could you please help us understand this definition of what is fatigue?
05:13
Well, Chris, there the problem we’re trying to define it, there really is no true definition of fatigue. If you talk to 20 different scientists, you’ll probably get about 40 different definitions of what fatigue is, it’s really based on a lot of times their personal area of interest. So my personal area of interest is extreme heat and cold. So a lot of times my definition of fatigue revolves around what happens because of heat and cold and things that those stressors directly cause. He talked to a muscle physiologist, and a lot of times, they will focus on the actual single muscle fiber and what’s happening in there, you talk to a metabolism researcher, and they will be talking about the different fuels, whether it’s fats, or carbohydrates, and glycogen depletion and how that is affecting the muscles. So it’s, it’s really challenging to come up with an overall definition, probably a good, basic, really fundamental working definition is just the inability to exert as much force as desired. And that sounds incredibly vague and wishy washy. But it’s really saying that at any one time, you are not able to work as hard as you want to work at that point. So first thing to do when talking about fatigue is really trying to get this broad general perspective overall, before really digging into individual models.
Trevor Connor 06:47
And I have to say, even though you say that, that sounds like a bit of a cop out, as you know, there’s a pretty definitive review of fatigue by by Abbess and Larson from 2005. And I’m looking at their definition right here. And it’s pretty much what you just said.
07:03
And it matches with what a lot of scientists have kind of come to this realization that it’s not necessarily just about their particular area. And this article that you mentioned, by Chris Addison, Paul Larsen, excellent, excellent article in 2005, outlining kind of how various different models contribute. So some of the models they talk about is simple changes within the muscle cells themselves, that causes a lack of power output or a reduction in force, there is the metabolic changes that I’ve talked about, there’s changes in movement efficiency over time, there are kind of biomechanical changes in gait, if you’re talking about running or in cycling, where you just get sloppy, and that’s adding to the extra work that you have to do to maintain the power output. And then there’s the thermal model, which, again, a lot of my work has been on looking at what happens when you are hot, and how does that directly affect your ability to sustain power. And then the final model is really somewhat contentious through the early kind of turn of the century. And for about a decade afterwards, this whole idea of a psychological component. And you know, we’re going to be spending a lot of time talking about that. But for many years, like you said, In the introduction, Trevor, scientists have just said, well, it’s physiology. It’s just because whatever happens in your body, and you can’t sustain power output, but we’ve come to the realization now that there is a huge psychological component, that there may still be this ceiling of physiology that you can’t get away from, but a lot of times, on a day to day, second by second level, how much power we’re willing to push on our pedals really comes down to more psychological constraints, rather than necessarily purely physiological ones.
Trevor Connor 09:07
Let’s get to that in a minute. But I think the important thing, when we’re talking about these older models of fatigue, you just gave it a huge list. And I’ve had athletes asked me, you know, what causes me to get tired? And my response has always been well, well, it depends, because it really isn’t one cause. And like you said, it almost sounds like a cop out. But there are many, many different things that contribute to fatigue, anything from muscle damage and soreness to overheating to running out of the basic fuels that you need to power the muscles. But the interesting thing they had in atlases review was he said that the the old belief amongst scientists, I think this is what you were heading towards, was that fatigue was some sort of catastrophic event that basically your body said I can no longer physiologically sustain this effort. So I am done. And it sounds like the old research was really looking for what is that catastrophic event?
10:06
Yeah, absolutely. And you have to look at the way kind of science is traditionally done, we are trying to control as many aspects as possible and isolate one factor, whether it’s the muscles, whether it’s the amount of glycogen in our body, and really test the effects of that. And a lot of the test protocols that we use in the lab involve, often what’s called a time to exhaustion test where you are asked to ride at a set wattage, let’s say 250 watts, and sustain that wattage for as long as you can. So you really at the end, you fail, because a lot of times of physiology you are have become hypoglycemic, you just become too hot, or whatever. So a lot of times, I think the the way we do science has contributed to this idea that there is a specific physiological point of failure. I’m not certainly not arguing that there is a point of failure, if your body gets too hot, you’re going to experience heatstroke, your cells are going to be nature. Absolutely, there is a physical point of failure. But again, in the last 10 years, there’s been more and more use of rather than these time to exhaustion test, having a much more open test, like a time trial, where you’re just told to complete a set amount of work as fast as possible, whether it’s distance, whether it’s the maximum power that you can sustain over 10 minutes, or a certain number of kilojoules. And I think that is a good change in protocol. Because a, it’s ecologically valid, it’s very similar to a time trial type effort in real life. And also, it has a lot more degrees of freedom, it allows you to change everything from the cadence that you’re writing, to your pacing, whether you start hard, and then you taper off, or whether you kind of ride more conservatively, your brain can, in essence, be making a lot more decisions, as opposed to a time to exhaustion where it’s simple. Do I stop? Or do I keep going?
Trevor Connor 12:25
Right. And that’s so that really brings us to this new model, which I’ve seen a few names for there’s there’s this looking as an integrated model, there’s a central governor, but it seems like this is the direction they’re going with with fatigue, which is this. It’s not one thing, that all these various factors that heat this substrate use muscle damage all these things, essentially, at some level, they’re they’re all being integrated for your central system, your brain to say, let’s look at all these factors and determine if there’s a we’re at a point where we need to slow down, we’re at a point of fatigue.
13:05
Yeah, absolutely. And probably the main proponent or the first major proponent of this kind of psychological model, in the last 20 years or so, as been Professor Tim Noakes from South Africa. He is very, very famous exercise scientists, he wrote the he wrote the classic book, The law of running that really, in ways helps sustain and set off the running boom. And he in around the early 2000s, I started proposing that a lot of what we’re talking about today that it’s not just physiology, the real reason for fatigue is the brain. And he called it the central governor model. And I remember sitting in a lot of his early kind of presentations as he was debating others about it. And one of his favorite slides to illustrate his point is he would put up a, a slide of a Ferrari or a f1 race car and ask the audience, how fast can that car go? And you know, people start saying, Oh, 300 k an hour or whatever. And then his response is always as fast as the driver is willing to let it go. Yeah. And if you think of, in that case, the f1 car being the body and the driver being the brain. His argument, then is that it really comes down to how hard is the body will or is the brain willing to work at any one time? So it’s a very kind of basic model. It’s been modified kind of, in a sense, improved and tweaked a lot. But yeah, at the very core of it, he started this model by really looking at a paradigm where of if you remember the Philippa T’s the rich You know, marathon runner where he ran the 26.2 miles and then he said, you know, rejoice we have one and any collapse and died. And his notes is essentially saying that, you know, that is what the body is trying to gauge it is trying to run or complete this work as quickly and as efficiently as possible without catastrophic collapse without reaching the point of festivities. So, the body is constantly integrating all these different ideas, whether it is physical cues in the body, how much glycogen I have, how hot I am, how thirsty I feel, to more experienced ones, well, historically, how fast can I run a, a 10 k? Or how fast can I do a 40 k time trial? How fast can I ride up this hill. So all of this is building this template in your brain of how hard at any one time in my willing to go? So that’s really where we’re kind of the models have evolved to this real time integration of a lot of signals in your body.
Trevor Connor 16:10
So you brought up an interesting point, when you talked about, you know, how can I how fast can I do this 40 k versus how fast Could I, for example, do attract kilo Turner, which study was a review was I read, but they talked about whether this central governor was in the heart or in the brains. And, you know, there was some belief that it would be in the heart because, you know, that’s what you really need to protect. But it sounds like, there’s also a big perceptual part, which would say this is mental and not only is this mental, it’s not all subconscious, as this governor saying, I’ve got an hour effort versus a five minute effort. So I’m going to perceive fatigue differently. Is
16:52
that the case? Absolutely. And I mean, we’ve all experienced this, right? You know, ahead of time, if you are going to be riding a 10 mile time trial, you know, roughly how fast even if you don’t have a power meter on or you put tape over the power meter, nine times out of 10, you’re gonna and you’re going to complete it, if you did this 910 times, probably nine times of it, you’re going to be really close in your pacing profile. And that just comes down to you learning and kind of setting up this template for how long? or How hard can i sustain an effort as opposed to if it was, again, a one k time trial on the track, you know, you can go a lot harder. So experience has a huge role in kind of how hard you’re willing to work. And certainly the studies that have been done on perceptual ratings of perceived exertion, the RP scale, you know, it’s not a static scale, your perception of effort changes. And it’s really helping you set up this template, how quickly can you set up this template, there was a really interesting study from Alexis Mauger in the UK. And what they did was they had two groups of cyclists complete a set time trial. And in one group, they knew exactly, you are going to be riding 4k, and you are going to get full feedback, a power output time, distance, whatever. And they did that four times over the course of a day. Another group, all they were told was, they’re gonna write the exact same distance four times over that day, they got no feedback, they had no idea how long it was. And the really interesting thing was the full feedback group, the very first time out. And the fourth time out, they were identical in terms of the pacing strategy, the overall time of completion, the average power output. But the really fascinating thing is, the group with no feedback, the first time, their time was really slow. But the third and fourth time, they were almost identical to each other. And they were pretty much identical to the group with full feedback. So your body really learns very, very quickly, what it can do and what it really is willing to do. Now, the flip side of that is, it can become a real trap, you’re, when you know, as a coach, you have to push your athletes out of their comfort zone can be really, really hard to push an athlete out of their comfort zone because they’re so used to doing an effort this way because it has become so ingrained into them. So that becomes almost The other challenge of if people can learn a pattern so quickly, how do we break them out of it so that they can actually ride faster. The classic example of this going back to running again is the four minute mile. People thought it just could not be done. There’s no way it could be done. And then as soon as Roger Bannister broke it Well, what do you know about a ton of people broke it off. Almost within that same year, so there is almost that huge psychological hurdle you have to jump through to break out of that template. And that’s one of the really kind of interesting offshoots of this psychological model.
Chris Case 20:12
So in this central governor model, it seems that there is this limiter this psychological or mental limiter. And I assume that through evolution that there has there is a purpose for this. And I’m curious to hear you guys both discuss the science behind that, what is the purpose of this limiter,
Trevor Connor 20:33
just go back, we really cover these limiters and this idea that a they are their relative, and the factors that affect them, and be the whole purpose of them is to protect your body from damage. And that means that these limits aren’t at the true point of your bodies about to die. It’s not saying we’re stopping you, you’ve got more in you, but we are stopping you before it becomes damaging?
21:02
Well, I would say that there are absolutely hard limiters, I don’t want listeners to go away thinking well, I can always push harder, I can always always push harder. No, there are absolute ceilings, that your body simply cannot go past. And if your body temperature goes to 42 degrees Celsius, your cells are going to start to denature the proteins are going to break down, there is no get no amount of psychology that is going to push you past that. So I don’t want to get across the message that there are no such thing as limiters, you can always go harder. Having said that,
Trevor Connor 21:43
let me go quickly to add to that there was a very interesting study where they had athletes do six kilometer 20 kilometer and 40 k TTS, obviously, your intensity is going to be different. And what they discovered was in the six k TT, where they are really going above what people think of as FTP or lactate threshold, the point of fatigue was completely peripheral, which is a breakdown it was acid build up lactate build up neuromuscular breakdown, so there was no central governor there, they were just fatigued, where those other links where they were generally staying at or below lactate threshold, it was much more central, you didn’t see that peripheral breakdown. But that was their conclusion that when you’re going really intense. It truly is your body is physiologically breaking down.
22:34
Yes, absolutely. So it really comes to the question of how often? And how close to that physical limit? Are we willing to go on a regular training ride on a club ride on a race or if we’re attempting the our record, like what I think one of the real concepts is about how to essentially turn off or or disable that emergency handbrake that we have, on our voluntary effort, how hard we’re willing to work. And that can be done by a variety of ways. And I’m sure we’re going to come up to point about some of the ethics of doing that work. But I feel that there are definitely limiters and again, the Abbess and Larson review, each of those models of fatigue, they present essentially present a different model of where the body ultimately will break down. And the psychological component really is about how close are we willing to push to those limits?
Trevor Connor 23:46
Is there a line that the body has? And is there a purpose to that line?
23:51
I think it’s self preservation is the ultimate thing. It’s, you know, you want to be pushing as hard as you can before you’re, you know, you pull a muscle, you pull a tendon and you you place too much stress on your knee and start developing tendinitis. So pain is an absolute, I think, evolutionarily designed to warn us of those physical limits. And whether it’s pain in the sense of a torn muscle, or that severe sense of discomfort from being hot, or severe thirst, those are all kind of your body’s way of expressing those limiters to your brain and saying you better pay attention because we are coming up to a critical point. And if you don’t slow down, we are going to be in trouble. So that that goes back again to the heart of this idea of the psychological model is ultimately your brain is integrating all of these signals and saying at this point in time, how hard Am I willing to work and it is a kind Have a feedback and a feed forward system where every second by second, you are constantly deciding on on that in real time.
Trevor Connor 25:10
It sounds like you’re saying, the point of fatigue is not the where you have completely depleted your reserves and you have nothing left. That’s the heart of all this is your your mind integrating all these signals and saying, I want to stop you before you do any sort of bad damage to your body. Unless, of course your your life is on the line, or there’s a purpose across that.
25:33
But those limiters, I would say, yes, are those absolute kind of point of failures, and you don’t ever want to be that close to it, it’s if you think about as an engineer, you’re always designing something with a safety factor, right? You are never just designing, designing a plane for you know, in a sense, everyday use, you are always adding a factor of two in terms of the G forces that it can handle, for example. So I think it’s a same kind of idea. And that has been integrated into the body over over the course of evolution is that you’ve developed pain to let you know, okay, you’re really, really close to the edge of your limiter. And then you have that whole range of discomfort before then,
Trevor Connor 26:17
to go with your analogy. It’s kind of like the the low gas signal in a car, it doesn’t go on when you are at a gas it goes on when you still have enough time to get to a gas station and do something about it.
26:28
Yeah, absolutely.
Trevor Connor 26:31
We had a chance to talk with American World Tour writer Sepp coos who now runs with lotto nL yumbo. We talked to SAP about this concept of fatigue and a central limiter and how it plays into racing. What was interesting was how much context such as the length of the race and the type of race played into the limits, and how much the limit was actually a conscious choice. Is there a limit that you are able to cross but if you cross it, you are going to pay for it? Like there is going to be damage that you are going to feel for for a long time after that? Or do you feel you can always handle it that you stop yourself before it truly becomes damaging?
27:12
For me, I think it’s I usually can stop myself I kind of see myself as a more not not conservative. But but I’m pretty familiar with with my limits. And yeah, it’s it’s hard to think of the times I’ve truly gone to that very, very dark place. Because, you know, even in some race situations, you’re never, you’re never fully fully emptying emptying the tank. Yeah, I have a rough idea of what my limit is. But I don’t know if I know what it will do to me, you know, hours or days later.
Trevor Connor 27:50
So is he
27:51
referring to?
Trevor Connor 27:51
Is it subconscious? Or is it conscious? Are you aware of that limit? And you just go No, I’m not going to go to that dark place? Or does it just your body’s going to stop you before you go there?
28:04
That’s a tough question.
28:09
I think I think it’s a bit of both, I think, you know, as someone that’s, that’s always training that’s always always racing, you kind of become more familiar with your limits. And so maybe that that goes back to your brain feedback saying, okay, no, it’s this point in the race or it’s this point in the time trial. This is not the the sensation, physically or mentally that I should be having right now. So I think I think for me, I feel in tune with those sensations. And yeah, it’s pretty, pretty conscious. I’d say,
Trevor Connor 28:45
that’s a really interesting point. You said at this point in the time trial. So let’s say, let’s do something, it sounds like you’re a little more comfortable if you’re going up a climb. If you’re five minutes away from the finish versus 20 minutes away from the finish. is the limit different?
29:00
Oh, absolutely. I think yeah, that’s, that’s a good example. I mean, that, that one K to go. That just that visual of that, I think, sets me and a lot of people off, you know, you say one K to go, that’s, that’s nothing, I’ll attack now. And then, you know, maybe maybe you go too early, because mentally you say, Oh, one K to go I can empty the tank, but it could be a bit longer. So you know, that opposed to starting the climb? And having maybe more more mental bullets or, you know, on the opposite end to you could start to climb and say, Oh, I have nothing left mentally I don’t I don’t want to be here right now. And I’m suffering. I’m already at my limit.
Trevor Connor 29:40
So is that different when you are? In a let’s say, you’re in a stage race? And let’s say guys are going super hard and you know, you’re going to empty the tank, but there’s still a race tomorrow. Do you to say I’m empty in the tank and we’ll see what happens tomorrow or do you say there’s a race tomorrow and Gonna let them get me because I still have to be able to race? Yeah, I
30:03
think it I think it depends on the point in the, in the climb or the the race. You know, I think a lot of the time, it was one way to go, if you totally go full gas, it’s, you know, the, it might be marginal whether you’re totally fatigued the next day. But yeah, I think you see that a lot in Grand tours, it’s, it’s totally a cumulative effect. And, you know, for me, if it was a mountain mountain top finish in a, you know, a time trial, the next day, part of me would say, Oh, I need to, I need to take time on on this climb. But then also a part of me would say, No, I can’t totally blow myself up, because I have to perform the next day. So yeah, I think I think at the end of the day, though, you just want to win. So that’s, that’s the, you know, the the overpowering force. So I had, and I you see that all the time, it’s, you know, they’re still very much that that competitive feeling. And some, I don’t think anybody would say, No, they, they would sacrifice the wind for, for that maybe one or 2% advantage the next day, you know, unless they’re truly, truly focused on the big picture of a grand tour, which you also see,
Trevor Connor 31:18
Sep touched a few times. And this whole idea that there’s a mental side to fatigue. Let’s explore that a little further.
31:26
Some of the really neat, newer studies coming out as has again, tried to look at what is different in the cognitive functioning, the how the brain works in elite athletes. And one of the studies that I personally found really fascinating was they compared using MRI imaging group of relatively sedentary individuals, recreational athletes, and compared them to elite level adventure racers, these are the guys that do do the five day kayaking, running, mountain biking, those crazy, crazy elite races, and these are the best of the best, they got them in, they looked at their MRI while they were doing these different cognitive testing. And in the middle, without kind of any prior warning in terms of the timing, they put in a really strong, painful stimulus and a painful stimulus was they restricted their breathing, they essentially cut off their air supply, the put it kind of in a very basic terms, and then they looked at their responses. As you can imagine, most of us, if we were faced with that, our mental functioning would go completely down our brain signals would just be, you know, going haywire. But surprisingly, the elite adventure racers, they actually didn’t have much if any decrement in or cognitive performance in the middle of that really, really strong kind of noxious almost stimulus. And their brain patterns weren’t that much affected above their normal baseline. So it really gets back to this idea of something about being really fit, or being really used to that sense of discomfort, you know, if you can just handle it better. And I find that study just incredibly fascinating.
Trevor Connor 33:30
I read a similar one to that where they took elite cyclists and amateur cyclists and had them do a time trial, I think it was a 20 minute time trial. And then a week or two later, they they repeated the time trial. But before they repeated it, they did 30 minutes of his cognitive functioning test that really tested your ability to focus. And it can be a mentally fatiguing test. And they found that not only did the elite cyclists perform better in the cognitive test, but then when they perform the time trial afterwards, the amateur cyclists, their performance declined, were with the elite cyclists it did. So they didn’t have that mental fatigue, they had that much essentially a trained ability to really handle cognitive focus.
34:19
Yes, and that really leads into how kind of we can train ourselves to, in a sense, put up with that discomfort better to get closer to those critical limiters. One of the studies that that came out of our lab at the start of 2017, I felt was really innovative. What we did was we took train, kind of club level cyclists. And what we wanted to do was we want to look at the effects of sports psychology intervention called motivational skills training, and we want to look at whether that can improve that Their tolerance to exercise and the heat and improve their exercise capacity. So what we did was we had a pretest. And then we had two weeks of either no psychological training or two weeks of this motivational skills training and another group, what was the motivational training that you were doing, because this is almost one of those things that people make fun of and say, Well, this is kind of silly. But the motivational training was specifically focused on improving how I feel in the heat or tackling that discomfort in the heat. So motivational skills training is really taking something that is uncomfortable, and then reframing that and kind of refocusing from it and reframing it. So for example, you may be writing, and you feel sweat dripping down your face, like oh, this is burning, this just sucks. I hate the heat. And what we taught the the cyclists to do is really reframe that into kind of almost being a positive. And that, you know, this is a sign of their being working hard and being able to push in the heat rather than framing it as this is a really crappy feeling. And then we got them to keep working on that over the course of two weeks develop kind of these reframing strategies, these mantras, these key words, the focus on when these uncomfortable feelings arose. And so they were all individually, it wasn’t a case of Okay, everybody, just, you know, think sunshine and lollipops, when things are hot, we got them to work on it individually and develop meaningful keywords of their own. So the test itself had them ride at a sustained pace for about half an hour, and that’s to get their body temperature up, get them starting to be uncomfortable, then we had to do a cognitive battery of testing, and testing a whole bunch of different mental function. And then we had them ride to exhaustion at a really, really hard effort when their core temperature was already high. The really fascinating thing was the control group, no difference in their cognitive performance after the two weeks as we would expect no difference in their physical performance. But in the, in the motivational skills group, they had better cognitive performance, even in the heat even before they started exercise. And also they were able to go about 25% longer. After the two weeks of motivational skills training, there was no difference in physical kind of capacity and their vo two max or anything like that. They hit a higher for an answer, correct? Yeah. And they hit a much higher record temperature afterwards. So again, it gets back to that idea of that psychological manipulation was able to essentially tweak how hard they were willing to work for how long. The other really fascinating thing was that if you look at their profile of how the ratings of perceived exertion developed over the course of time, after the two weeks and motivational skills training, they still got up to a really uncomfortable feeling of 19 at about the same time as before, but the big difference was they were willing to tolerate that really severe discomfort for much longer period of time than they did before. So that also, I think, points to the fact that our our psychological intervention was successful, they were able to tolerate much more discomfort, and that included both the physical discomfort and also the thermal discomfort.
Trevor Connor 38:51
So there was no improvement in physiological fitness. It was simply we were talking about that limiter they were able to push that that limiter up.
39:00
Yeah, I believe that was the reason for it. It definitely wasn’t because they had a higher vo two, Max after those two weeks, there was no difference before and after when we tested that.
Trevor Connor 39:17
Yeah, so Chris, I think I almost just had a heart attack, we accidentally put up a rough version of one of our podcasts and quickly got it down and put up a new one. But I certainly felt my heart coming up through my throat when that happens. So may it had me thinking, thinking about what, think about whether I needed some life insurance.
39:39
You always need life insurance.
Trevor Connor 39:42
Let’s in all seriousness, talk a little bit about health IQ, which is a life insurance company that specializes in healthy active people like cyclists, runners, and hopefully ourselves. They are able to give us favorable rates for life insurance and they have a special URL just for Fast Talk which is www Health IQ comm slash Fast Talk, where listeners of the show can go for their free quote, while you’re there, you can submit race results screengrabs of your Strava or map my run account or other proof that you are indeed a regular cyclist and get a better quote.
Trevor Connor 40:23
It’s fascinating when you you’re talking about this, this idea of fatigue, just how much research there is out there showing that your perception, your understanding of your environment, contributes and I’ve read a study right before this, I thought was fascinating where they took subjects had them do a 200 meter or 2000 meter run. In one situation, they just had them do the run and other situation, they had them believe that they were competing. And when they thought they were competing, they were faster. And as you pointed out with the RP scale, their perception of diff of what was hard, was different. You know, they had different RP Yeah, it really is amazing. It seems like this fatigue is somewhat relative to a very conscious level of understanding of what your your situation. And so in a lot of research, they talked about the endpoint, how close Am I to the finish? Am I competing? And how hard is this?
41:19
Yeah, and that goes back to one of Knox’s classic arguments for the central governor motto is that there is almost always no matter how fatigued someone is almost at the end, they can still be sprinting, there’s always that end spurt. So it shows that for the bulk of the time, they were running or riding beforehand, they weren’t going to their physical Max, because if they were, they shouldn’t be able to sprint at the end, they should just be continuing on to finish at the same pace. So yeah, that’s certainly one of the classic arguments from Noakes about this whole kind of idea of a psychological component.
Trevor Connor 41:57
I think I read that study you were talking about, it was absolutely fascinating, where they had pretty sure they had it was cyclists on amateurs, and they were instructed to ride to fatigue, literally right to the point where they could not go another second. And the researchers would say okay, so you can’t pedal another second. No, I can’t pedal another second, then they go do a 15 second sprint, every one of them could do a 15 seconds sprint, and they could actually put up good power.
42:26
That sounds like good old Russian, Soviet era East German training there.
Trevor Connor 42:32
Yeah. Doesn’t sound like fun. But the point they made in that study was when it was again, that perceptual side how much it affects fatigue, because when it was an open ended activity, it would just go tell fatigue, so there’s no time on it, there’s no length, you might be going 15 minutes, you might be going two hours, you don’t know, that gives you a much lower perception of what you can handle or fatigue. When they were told sprint for 15 seconds. That’s an endpoint that’s very close. And that seems doable. So all of a sudden, they’re not too fatigued to keep going.
43:11
Mm hmm. Absolutely. I think that knowledge of endpoint is really important. As I mentioned that study by Margaret, once you know the end point, you know what you can do, and most of us in that sense, has done a 15 second sprint of some kind.
Chris Case 43:30
What one particular thing that I would point out and I know Trevor has some thoughts on this, as well as having done the our record myself and having read about the different efforts that went on from big names, Masters in a sense of their sports with Wiggins and yen’s, and the others that breaking down a an effort like that, into segments really helps one digest what they’re getting themselves into, but also, in a sense, fool themselves into thinking that it’s not as daunting a task as it actually is. And I believe yen’s broke his effort into 320 minutes segments, Wiggins broke his into even more segments, I did the same as well, and you think of these chunks and you, you kind of have to acknowledge that it’s, it’s a bit silly, I guess, because you know, you know that you’re going to be doing 60 minutes, but at the same time you do, you do a six minute segment, and you’re able to rise a little bit higher during that six minute segment, you hit that quote, finish line. Ah, I’ve got another six minute segment and you go a little bit deeper in that one, not not that each each segment you go harder and harder, but you’re able to lift with each of those a bit more than if you just accepted it as one giant 60 minute daunting effort.
44:56
It’s really interesting. You say that Chris? Cuz I think I thought I was just crazy. But it’s actually very similar to in a way, how I seem to be able to handle writing in races where I’m way over my head. And we have these club races in St. catharines, where it’s just screamingly fast, kind of four corners, three K, kind of total laps and, and I’m just suffering them, the guys are just flying. And it seems what works for me is I kind of almost give myself permission to quit, but only at the end of that next lap, right as if I can hang on to this next lap to cross a line, then I can quit, then magically, when I cross the line, I seem to have an Etch A Sketch. And I erase that memory as it’s okay, if I can only make it in the group to the end of the next lap, then I can quit. And it’s like, it’s almost seems to be exactly what you’re saying, Chris, that you just break it down into segments, and you push yourself as hard as you can. And then you kind of get on to the next segment, before your kind of brain realizes what you’re doing. Exactly,
Trevor Connor 46:03
it goes back to what we were saying before that your perception or your where you put that limit for fatigue is determined by by the end point, you know how much is left. And if you can essentially move that endpoint closer to you, you’re gonna raise that limit on what you perceive as fatigue. I had a Altoona I think it was 2006, it was a bit a day it was close to 100 degrees, we were 110 miles stage. And our feeder missed me at both feeds zones. So we cross it a climb about probably 20 miles from the finish, I was dramatically dehydrated, and had made the lead group but was just dying, and I spent that entire 20 miles just look up the road, see a telephone pole and go make that telephone pole and I can pull the plug. Soon as I got to that one, I’d look to the next one, I go, okay, make it to that one. And then I can pull the plug and got to the finish of the race doing that just breaking it literally down into 32nd segments.
Chris Case 47:00
It’s a it’s a it helps performance, I can’t say that it in the end, it makes it any more comfortable. But you might get a little bit more out of yourself. It’s a little bit like torture.
Trevor Connor 47:12
The one I will add is, as we said before your your limit depends on length. So it’s really important as a cyclist to learn those various limits. Meaning I’ll often have riders come up to me and say I want to be or say I want to be a better climber. My first question is what link climb? Because your limit for a two minute climb is very different from your limit to a 30 minute climb. So it’s good as a rider to go and start learning. What is my pace? What is my limit? If I’m doing a 30 minute effort? What is it for a five minute effort? What is it for a 15 minute effort. So when you’re faced with those situations, you know how hard you can go.
47:51
Getting back to your idea about the perception and almost fatigue, and discomfort as a as an emotion. Rather than just a kind of physical cue. There’s been a lot of really intriguing evidence in the last while about the effect of training and effect of fitness. And, you know, there’s almost a train of thought or a school of thought that says, when you are training an athlete, you’re not just training physically, but you’re training them to be used to discomfort. One of the really nice studies that came out in my field of temperature regulation was came out of my PhD lab in 2002. by Peter decreases. They had a group of relatively unfit individuals and a group of highly aerobically fit individuals. They were testing the chemical warfare clothing, the Canadian military war, and having them wear it into heat. And they had them walk until they quit. And the really interesting thing was in terms of their physical strain, how hard it was for the fit, and the unfit group was about the same. Obviously, the fit group went for longer. But the really interesting thing was the perceptual strain for the non fit group matched their physical strain. But the fit group, they were working just as hard, but they didn’t feel as put out nearly as hard in terms of their perceptual strain. So it really gives some evidence to this idea that one of the benefits of fitness isn’t just a physiological improvement, but your ability to tolerate that discomfort. Some of the newer studies that have been coming out has been looking at the effect of brain chemistry and a lot of your different neurotransmitters in your brain. One of the chief ones has been looked at as dopamine, which we often call kind of the happy drug. And this was a study that was done by Bart rowland’s, who at the time was a PhD student And at the Bri University Brussels in Belgium, and it was actually funded by water. Because what water was interested in was, there’s a potentially a lot of individuals or athletes who are taking antidepressants like Ritalin. And what effect does that have on their performance if we know Ritalin, essentially, is what’s called a dopamine reuptake inhibitors. So that means it, it slows down to decay and destruction of dopamine that is naturally in your brain. So if you take Ritalin, you tend to have more dopamine in your body. What Bart did was a really neat study where he had them do had Fitz cyclists do time trials, one with placebo, one with very low sub therapeutic dose of Ritalin. And he had them through the time trial in normal temperature, so about 18 degrees Celsius, and they also had them do the time trial and 30 degrees Celsius. The interesting result of this study was that there was no difference in the placebo, or the ruling group in the low temperature in the 18 degrees Celsius. But in the 30 degrees Celsius condition, they were able to ride at a much higher average power. And also as a result, they were willing to put up with a lot higher final core temperature at the end. So something about the combination of exercise and heat, and also the Ritalin. And the elevation of dopamine from taking Ritalin allowed them to perceive the effort to be less, and therefore be willing to ride at a higher power output, and as a result, generate more heat and tolerate a higher body temperature. And that kind of fits in with what we talked about before with that study on fit non fit individuals and their perceptual versus physiological strain. It could be that fit individuals, whether it’s because they’re more inherently motivated their use of the discomfort, they’re able to, you know, have some neural transmitter changes that enable their body and their brain to push harder. And that’s actually some of the work that I want to be pursuing in the coming years to look at the effect of these perceptual changes on your exercise performance and your muscle function.
Chris Case 52:30
I could see people out there getting really excited by this notion that you can trick yourself or fool yourself or or train yourself to raise these limits. But it seems like there’s an ethical question here of whether you could go too far. Do you put people in danger if you do this? I’m assuming this has been a consideration in your research as well.
52:54
There absolutely is a consideration in this. And remember this study on Ritalin that I talked about. It was originally funded by Wada. And the reason for it was they were afraid that people were going to start abusing and being prescribed unnecessarily, these dopamine reuptake inhibitors so that they can fool themselves by taking this drug into being willing to work harder and willing to tolerate a higher body temperature. So that was the exact reason why why to fund it, this specific study. And it raises this whole ethical question, as you pointed out, Chris, is, how far can we And should we be going in terms of tweaking these limits? It’s one thing with a little bit of sports psychology, it’s quite another thing, maybe in terms of taking, taking a unnecessary substance like Ritalin if you if you are not needing it for a real true medical reason. Another one is the several studies of again, with heat tolerance, where they’re having people do mouth rinses with mouthwash, which gives you a sense of sensation of cooling in your mouth. And that also extended time to exhaustion, basically tricked their bodies into thinking they’re being cooled when they weren’t. Mm hmm. And the same thing also with some other pre cooling strategies, like with neck collars, or neck bandanas, there’s very little actual thermal cooling going on with them. Most of it is perception, you are feeling cooler, mainly because your neck is cooler and your neck has a lot of kind of sensors that feed into how cool or hot that you feel. So if you call your neck there’s actually no real, actual direct cooling going on, but it’s making you feel cooler and again, you’re then able willing to push yourself harder. So you really have to question When an F, you actually want to be doing anything to really kind of, in a way affect your psychology, especially in a, in a really, really intense situation where you can be already running pretty close to that limiter or whatever limiter you have to begin with
Trevor Connor 55:21
something you need to be careful of I, unfortunately, over the years learned to really push my limits, I’d have my body’s screaming at me saying stop, and I’m pretty good at being that grouchy guy’s hand back to my body. Nope, keep going on. And you can get in trouble for doing that. So for example, I had one race where I had been sick, I’ve been throwing up all night the night before. And I decided to start the first day of ILA got to the top of the climb. And I just remember crossing the finish line. Apparently, I was just wandering kind of aimlessly, somebody grabbed, my blood pressure was 70 over nothing. They put me in a in the medical tent, and I got two IV bags, blood pressure still wasn’t back up. And they were thinking about taking me to the hospital for some more bags. And it was a month before I was anywhere close back to normal after that. So I mean, when you push these limits, in unhealthy ways, there’s a price to pay.
56:20
Yes, absolutely. So the last thing I want listeners to go away with is thinking, wow, I just learned all these different ways I can kind of fool myself. And I’m going to really put all of them together as you know, my next marginal gains for my next event, it’s, I would look at them more as giving you insight into areas that you can improve your performance rather than saying, oh, I’ve I found my new silver bullet magic bullet. So I really want to put that caution out for listeners to to really be careful. And don’t just try things willy nilly. And really consider whether you actually want to be full and your body in a sense.
Chris Case 57:04
Are there any, you know, Hallmark warning signs that you you are tricking yourself into a dangerous place?
57:12
Certainly with temperature, the really dangerous sign is if you are not sweating anymore. And that is one of the classic Hallmark symptoms of heat exhaustion and heat stroke when your body is so hot that it It can’t even sweat anymore and your skin becomes really, really pale and cold. That so that is certainly from that perspective, one of the classic symptoms from metabolism. If you become really hypoglycemic, you know you’re gonna feel it. You know, that’s that bonking is another classic symptom that there’s really no getting out of jail if you if you hit that level too. So those would be two of the classics, obviously, any sign of actual kind of acute pain from pulling your muscle or anything like that, that’s going to be another sign. So, you know, the signs are definitely there. They’re very easy to tell, but you still have to pay attention to them.
Chris Case 58:15
Well, that was a very fascinating discussion today. Thank you so much for your time, Dr. Steven Chung. It’s been a pleasure to talk with you and we hope to have you back on Fast Talk again.
58:26
I really enjoyed it, Chris. And Trevor, thanks again for having me on.
Trevor Connor 58:29
Thank you.
Chris Case 58:30
That was another episode of Fast Talk and a fascinating one at that. As always, we’d love your feedback. Email us at web letters, web letters at competitor group.com Subscribe to Fast Talk on iTunes, Stitcher, SoundCloud and Google Play. Be sure to leave us a rating and a comment. While you’re there. Check out our sister podcast the velonews podcast which covers news about the weekend cycling. Become a fan of Fast Talk on fast on facebook@facebook.com slash velonews and on twitter@twitter.com slash velonews. Fast talk is a joint production between velonews and Connor coaching. The thoughts and opinions expressed on Fast Talk are those of the individual for Trevor Connor, Dr. Steven Chung. I’m Chris case. Thanks for listening
