Episode #367: Training Load ft. Dr. Franco Impellizzeri

26:37Dr. Franco Impellizzeri:Maybe you are even a bit hungry that day for some reason you can push harder and another day you push less. So there's no measure that is not influenced, especially in sport where it's all performance based and performance is very influenced by motivation. There's always some sort of other influences. The importance is to understand and knowledge the limitations of the measure that you're using. So if you're using RP, you know that this can be influenced by other factors. But the same is heart rate. The same is even if you use EMG. This can be influenced simply by where you are placing the electrodes.

27:19Dr. Franco Impellizzeri:So there's no such a measure like perfect or gold standard measure. There are a lot of measures. So the way I think people may interpret trend load monitoring is like having pieces of information that in isolation, they don't tell you a lot, but when they combine, they can give you a better picture of the situation. So you may want to use RP, heart rate, you use external load, you combine all this information and you try to see if there is a trend in some direction. And I use often the term trend because trends are what we are observing. When you measure something specifically in that session with that athlete, it's just a picture of that moment.

28:11Dr. Franco Impellizzeri:And so let's say that the perception is higher. It may be because the athlete is tired, because the day before they did something, they didn't sleep well. the day after the same exercise can induce a slightly different kind of response. And that's why I'm saying internal response is actually important, because in the end of the day, it's the internal response that determines how you are improving, or the adaptations, all these kind of things. So the way, and we wrote that several times, you understand how to monitor athletes is by measuring all these responses. so you measure the stimulus you try to measure the response heart rate variability normally is a response so you measure after the training to see how you're responding and the assumption is that the the magnitude of the response is in some ways related to the magnitude of the stimulus so and you try to balance this and this is a way to understand the training tolerance of the athletes and normally as i told you i'm a coach so i i used to train people at at the limits.

29:22Dr. Franco Impellizzeri:If you have to go to an Olympic Games, you don't want to go there as a tourist. You go there to compete and have some chance of either winning or having a good placement. And the only way to do that is to push the athletes. I cannot cut half the volume of training because I reduce the injury risk or this kind of thing. Yeah, that's true. But there is actually a simple reason why you reduce the risk because you are training less. So the time metric is lower. But this also means compromising the possibility to excel in the performance. So that's normal. And this is why you try to understand the tolerance and to work closer to the tolerance, at least in high-performance sport.

30:08Yeah, effectively you're trying to get people to be able to, especially athletes at that level, to effectively maximize as much training as they can do without blowing themselves up, in this case an injury or otherwise like losing motivation, overtraining syndrome perhaps, something like that. But generally speaking, the more you can train and tolerate that, that's a hedge that the more fitness adaptations and the higher your performance is likely to be later on. And so, yeah, to your point, you and I together, we could mesh our brains together and come up with a training program that has zero injury risk.

30:48you just you just wouldn't train at all you just wouldn't do anything it wouldn't be very effective but uh no injury yeah we're injury free you know so yeah yeah that was one of the biggest

30:57Dr. Franco Impellizzeri:discussion i had when all this mess of training loaded injuries uh started 10 years ago because for example people are scared about fatigue and say well but you know that when you train someone you actually want to induce some fatigue otherwise you can't train so the fact that an athlete is perceiving fatigue for me it's not a problem. The problem is that the fatigue is higher than what I expect or what the athlete is expecting. That's because this means that I have I don't have control on the process. But the kind of narrative we have created as poor scientists is that people should be scared about training, about fatigue.

31:38Dr. Franco Impellizzeri:I mean there is a risk when you train. There is a nice study about training loading injury in hockey players. It was the only study that I consider well done out of 100 and this was done by Jan Schreier group in Canada. So basically they use a medical time target trial emulation so they try to emulate the target trial with the observational data and what they have done is interesting because they didn't only They examine the increase in the risk, increasing the participation in the sport. But they also compare this increase with the increase that you would expect just because you are training more.

32:22Dr. Franco Impellizzeri:So in other words, if you are sprinting 10 times, you have half of the risk than sprinting 20 times because you are exposed more. Yeah, and this is where people got tricked by the fact that they didn't realize that the training is both the stimulus, but it's also the time at risk. So the more you train, the more you are exposed at risk, but still you need to train. What they have shown is that the more you train, the more you increase the risk of injury, which is actually what we expect. but the increase is lower than what you would expect by just increasing the time at risk. It's like a paradox almost, yeah.

33:02Dr. Franco Impellizzeri:Yeah, no, it's actually, there is a protective effect. So the more you train, the less injury-prone you are. Of course, since you are training more, the risk is increasing because you are just doing more. But there is a protective effect of training itself for injury. And how much you have to train someone, it's in relation to the performance. It's a risk-benefit analysis. That's it. Before an Olympic game, you can risk much more because the benefit may be higher than during the season, for example. So, yeah. Yeah. I think people don't appreciate that because they're like, well, look, if you increase training load too rapidly, for example, for an individual to tolerate it, well, injury risk goes up a lot.

33:53That's the assumption, right? But there's little caveating around that where it's like, yeah, but their performance could also go up a bunch too. And it's probably not the potential for benefit. It's probably not proportional to the potential for injury. In fact, in this case, you would assume that the potential for benefit is actually higher than the potential for injury. And you're like, we're just, it's an optimization problem. We're walking this tightrope and trying to figure out, you know, should we push or not? Yeah.

34:24Dr. Franco Impellizzeri:Absolutely. And that's why you monitor training because you have normally, I hope people, coaches have a plan in their mind. So you want to just see if the plan is going as it was supposed to go. So this is why you monitor that. I don't think you can discuss monitoring without discussing also the training program. This is where I find myself a bit uncomfortable when also I have these kind of interviews, people asking what kind of matrix. Yeah, I don't know. What's your training? Based on the training, we can discuss what can be the best. But it's not only what is the training, what is the goal of your training?

35:09Dr. Franco Impellizzeri:why you are jumping why you are doing I don't know power cleans I suppose there is a reason so based on the reasons why you are doing that we can decide what to monitor but everything is around the coach, it's not around the sports science department and this is actually a bit my personal and different perspective than other colleagues Yeah. Yeah, well, especially if they're in the sports science department, they're like, hey, what are you talking about, Franco? Come on. Why are you cutting us out? And you're like, well, this is not where the decisions are necessarily made. I gave a presentation at the European Powerlifting Conference in 2019 talking about injury risk in powerlifting, right, and some ways to maybe reduce that.

35:58Like what's the lay of the land? What is the average injury risk per 1 ,000 participation hours? It's about two to four, depending on the population that you look at, which is compared to other things, pretty low. And then so, you know, how would you manipulate this? How could you make it more risky versus less risky? And then, like, how does it interplay with performance? And at the time, one of the metrics that had been put forth to track is this acute to chronic workload, which is probably more geared towards either team sports, endurance sports, whatever, just because the time component is so pertinent to the mediating mechanism.

36:35In endurance sports, that's your volume. Basically, in team sports, it's your exposure. Not too useful for resistance training, tracking, because, like, you could be in the gym for three hours and only have done, you know, 15 sets, whereas that could also have been done in an hour, right? So it's not perfect there. So I'm wondering if you were trying to come up with some sort of variable to monitor with respect to injury risk in resistance training, do you have any ideas about how you would go about monitoring that? And if you just want to throw your hands up and say, I don't know, that's totally fine too.

37:11I'm just more curious. No, I mean, I don't know, but because there's no literature that can help us understanding that.

37:21Dr. Franco Impellizzeri:I mean, I know I'm saying that and most colleagues would probably disagree, but I can defend my position everywhere in front of everyone because show me a good study explaining what metrics we can use to monitor or to control for the injury risk. and I can show you why these studies are not good enough to understand how to do that. I'm not saying that we don't have to try. It's a different... Yeah, right. Yeah, I'm just saying that this idea that there are some scientific methods to control for the training load in order to limit the risk of injuries is not true. It's simply not true. It's a wishful thinking, but it's not true.

38:15Dr. Franco Impellizzeri:there's not such a metric. There are things that we do, and if you think about it, one of the reasons why the acute chronic ratio became popular is because the message is actually a message that is familiar to coaches. Like, you know, you have to avoid spikes, you have to follow progression. The first time I started to read about these races, I said, well, but this is actually the normal, let's say, training methodology. I don't see anything different. And people start to say, yeah, but now we have the proofs. And I say, no, that's actually not the proof. And we published the reasons why this ratio doesn't provide the proof.

39:04Dr. Franco Impellizzeri:But at the end of the day, the reason why people accept some metrics is because they fit with our idea of good training. I recently posted a study, one of the biggest studies, there are more than 5 ,000 runners, and they also use the acute chronic ratio. The study is properly done because they also use a causal inference approach to understand the causal relation. long story short their study which is unquestionably one of the best done until now show the opposite trend so that the higher this ratio the lower the injury risk and of course no one advertised this study because it goes against what we normally think because based on the study the faster and the more you increase the lower is the injury risk that doesn't make any sense.

40:04Dr. Franco Impellizzeri:But the meters are much stronger than the other studies showing that the spikes are dangerous. So people just pick the results that fit their idea. So my point was, okay, if you're just selecting the studies that fit your idea, we don't need the study. Just go on and do what you think is good, and that's it. Because if out of one other study, you pick the 30 that support your idea and you are ignoring the other 70, what's even the point of running all these studies? Just do it. Just do what you want. And I would be comfortable to follow. And this is what I do. Sometimes I prefer to follow these experience-based approaches than strategies based on weak evidence.

40:56Yeah. Yeah. No, that's a good point. Yeah, if you're just going to do whatever you want to do anyway, you don't need literature to support that. Just do it and don't tell anyone. Whatever. You don't have to explain yourself. One of the metrics we've been trying to – we're collecting data on. So we have an app, right, with tens of thousands of people that log their training in it. And I've been coming up with this – it's like a training impulse score. It effectively takes the average intensity, how many reps you did, the proximity to failure of that set, right, using RPE with the reps and reserve anchor.

41:30And then was it a compound exercise or an isolation exercise? I think those two things affect people differently. And was it on a machine or was it freestanding? I don't know why I believe that a compound freestanding exercise imparts a slightly different sort of stress to somebody than an isolation one done on a machine. but that's my belief system. I'm open to being wrong. Anyway, and so I'm trying to figure out, does that, is that a good proxy for like training load insofar as it would mediate the injury risk and then also people's sort of arc for strength in this case. The arc towards strength, it's pretty good.

42:11Like I'm seeing some pretty good correlation there. I like that. We haven't obviously tracked injuries in a prospective way just yet, But that's where I'm trending. But I'd be happy to not only get your thoughts on that, but also for somebody to prove me wrong and say, actually, that's all bullshit. You don't need to measure all of that stuff. Just measure this other thing. Maybe it'd be something more or more simpler like, hey, do you feel like an injury is coming on? The person could predict that ahead of a session. You just ask them. For example, I'd be happy if that were the case because, hey, look, I don't have to track all this stuff.

42:41I just have to ask you before every training session, hey, how are you feeling? And then I can just use that. you know?

42:47Dr. Franco Impellizzeri:Yeah, well, this is actually, this is the reason why I started to use RP, because in the end of the day, I was thinking, okay, when you train someone as a coach, and you are on the field, you try to understand how they are responding to the training, that day they are fine, you speak with the others, say, how do you feel today? And if someone is telling you, today I don't feel well, I'm not concentrated. You normally adjust the training based on this feedback. So I started to say, okay, but if we actually use this kind of feedback from the answer, why don't we try to quantify a bit this kind of information so that I can use to monitor training?

43:31Dr. Franco Impellizzeri:So that's why I found perception important. And when people told me, yeah, but this is influenced by psychological aspect say yeah that's actually why I think is important because I want to know yeah yeah it's a feature not a bug yeah yeah yeah for me it's it's more dangerous that you you you you you complete some exercises when you are in a bad day you are not very concentrated these kind of things because you can you know that technique can be you you don't focus on the technique and this can create problems so these are the kind of information that I think are important So coming back to your initial question, I think that measuring all these things may be useful to understand why something happened.

44:14Dr. Franco Impellizzeri:You can't predict what is going to happen, but if something happens, you can try to understand why, for example, I had this injury or why the performance was so bad. And if you have different information, for example, you have these objective measures, but you also have some perception and maybe the others told you something and you ignore or you didn't focus for some reason on this kind of feedback. So you go back and you try to understand why something happened in order to, in the future, to avoid what you may think were mistakes. But predicting something happening in the future is the most difficult thing you can do.

45:02Dr. Franco Impellizzeri:Even with this machine learning, all these kind of methods that we now have, most of the time the work, you create the model based on what happened in the past. and what is going to happen in the future is something you have to test. This is called external validation. It's commonly used in clinical setting where you have a prognostic model and you want to validate in a new population or even in your population, but in the future. That's an important part because it's much easier to fit a model with all data. It's much more difficult to use that model to predict what is going to happen in the future, which is what most people in reality want.

45:43Dr. Franco Impellizzeri:So this is the reason why I think monitoring all this information can be useful. In addition, it's also to understand how athletes are coping with the training, so with the stress you have planned. I'm hoping the key is always to try to understand how they are tolerating the training. and to do that you don't need only to measure the training load, you need also to have some measure of responses. It can be measure of fatigue or even perception, heart rate variability, doesn't matter what you're using, but you want to understand with that specific training load what is the response and how is this response moving, is moving in the direction I want.

46:31Dr. Franco Impellizzeri:So there may be a period in which you decide to intensify the training and you know that two or three weeks of intensified training will induce fatigue. So if you start to see an increase in fatigue, that's not the problem in my opinion because that's actually what I wanted to do with my training. but if for example after a while I lower the training load and I see that fatigue is not going down, this can be a sign that something is going wrong and so this can open to additional investigations, asking the athletes maybe sometimes you can also do some medical screening. This happened when I was working with cyclists.

47:18Dr. Franco Impellizzeri:They were not responding well. It happened that sometimes we realized that we had viral infections and these kind of things. So you see a deviation from what you plan. And this is, I think, the only reasonable thing you can do now with all these measures. I'm not saying that in the future maybe we can develop something stronger at the moment. that I don't see this happening, even if there are a lot of wearables now, so there are a lot of information coming. But moving from this information, from this data to real information, this is another beast. Yeah, ideally you would have some objective stuff, right, these metrics, and you'd have also some subjective feedback.

48:03Again, like, how are you feeling? Do you have heart rate variability, which is something, an objective number, but somebody could report that. Are you sore? Do you feel like you have pain? stuff like that. And yet blending those together and seeing like, well, is this the predicted response based on the change in the training? Or is it, oh, this is far different than I expected. Wonder why. And then you got to dig deeper. But I don't know yet how this is all going to pan out. And if somebody else did, I wouldn't have to do this work. So we'll see what happens. Every few episodes, someone asks if eating more protein is going to wreck their kidneys.

48:36Now, for most people, the data on that is very reassuring, but lead in your drinking water is a different conversation. The EPA and CDC agree there is no known safe level of lead exposure. The EPA's health-based goal for lead in drinking water is zero, and we're nowhere close to that. The problem is that there are millions of lead service lines still in the ground across the country. So the pipes, the solder, and the plumbing between the treatment plant and your faucet break down over time, and that's how lead gets into the tap water. There's a federal mandate to replace them, but it's on a 10-year timeline, and most of that work hasn't started yet.

49:08In adults, chronic low-level lead exposure has been linked to all sorts of things like kidney damage, high blood pressure, and cardiovascular disease. And these are claims from the WHO and CDC's position. The thing is, you'd never know from looking at your water or tasting it. That's why I've started filtering my water with CovePure. It's a countertop reverse osmosis system. There's no plumber, no installation needed. You plug it in, it sits on your counter. And reverse osmosis is one of the most effective filtration methods for removing lead, PFAS, arsenic, and nitrates. The first thing in the morning when I'm filling up my kettle to make coffee, I use CovePure.

49:39It's got a touchscreen where you pick the temperature you want, hot, cold, or warm, and it dispenses instantly. It also has preset cup sizes, so you can keep track of how much you're taking in. For America's 250th birthday, CovePure is giving you$250 off at covepure.com. That's C-O-V-E-P-U-R-E dot com slash B-B-M. This podcast is brought to you by Factor. Eating well isn't a willpower problem for me, and it's probably not for you either. It's a setup problem. There's something healthy in the fridge that I should be making, and then it's 8 p.m. I've been at the track all weekend, or the workout went too long, and then the gap between should cook and will cook is roughly the size of the Grand Canyon.

50:18So if left to my own devices, I'll order something for delivery and feel great about it for approximately 11 minutes. That's the gap that Factor closes. Fully prepared meals designed by dieticians, made by chefs, delivered to your door, and they're ready in two minutes. No planning, no grocery run, no cooking. They've got meals built around whatever you're after, whether it's weight loss, more protein, overall healthy nutrition, GLP-1 support, and a muscle pro collection if you're training hard and you care about recovery. The food's fresh, never frozen, with over 100 meals rotated weekly, so you're not eating the same chicken and rice until you hate it.

50:50Lean proteins, whole foods, only the stuff you want, and it's pretty good too. Head over to factormeals.com slash BBM50OFF and use code BBM50OFF to get 50 % off and a free daily greens box. If that's something you're into, that's with new subscription only while supplies last until september 27 2026 see the website for more details let's talk about the cold war happening in your bed no not that i'm talking about the temperature one of you is a furnace and the other one's got cold feet like two blocks of ice and somewhere around 2 a.m somebody's stealing the covers and someone's throwing them off nobody's sleeping everyone's mad the chili pad 2.0 actually solves this it's a water-based mattress topper that controls your sleep temperature, anywhere from 55 to 115 degrees, and the dual zones are the whole point.

51:34You run your side cold, your partner runs theirs warm, and the thermostat negotiations are over. It works with the mattress you already own, so you're not buying a whole new bed. And the new nightstand remote is pretty clever. Each side gets its own thermostat, and it's got sensors that notice when you actually get in a bed and start your schedule for you. So it works even if you're the type who means well, but forgets. There's no subscription, you buy it, you own it, it's got a two-year warranty, It's designed and assembled in the USA, just north of Charlotte. And a cooler bed is one of the better supported ways to fall asleep faster.

52:03And honestly, I just stopped waking up annoyed and a little sweaty. Visit www.sleep.me to get up to$255 off your ChiliPad 2.0 with code BBM. Again, that's www.sleep.me. This is available for Barbell Medicine podcast listeners for a limited time. Order today and get free shipping and a 30-day sleep trial. The best thing about summer in San Diego is how little I have to think about getting dressed. No coat, no layers, no checking the weather because the weather is the same. Heroic 72 degrees, it always is. I basically own two seasons of clothing and use one of them. Which is how I ended up living in Quince.

52:45They make well-built essentials, the kind of pieces that quietly become the only things you actually wear. They're 100 % European linen pants and shirts are breathable, easy to throw on, and they start at just$34. The t-shirts are soft enough to wear all day and the lightweight cotton sweaters are what you want when a summer night finally cools off. And everything's priced 50 to 80 % less than similar brands because they work directly with ethical factories and they cut out the middlemen. So you're paying for the quality and not somebody's logo or marketing campaign. And it's not just clothing anymore.

53:15Quince has turned into my go-to since I've moved into a new home and they've got travel stuff as well. I use this and you should too. Make your summer wardrobe easier. Go to quince.com slash BBM for free shipping on your order and 365-day returns. Now available in Canada too. That's quince.com slash BBM for free shipping and 365-day returns. With the wearables, that actually brings up a question I had for you. So many studies are using statistical associations between training load and injury risk, but inferring causality, as you'd mentioned, it's challenging to be charitable, if not inappropriate, just based on the methodology that's being used.

53:52So what's your take on a listener who's got a fitness tracker and they get some sort of training load score, whether it's strain, for example, or some other proprietary number? Is that useful information and should they be asking themselves or their coaches to make sure that they're in a particular range? How do you view all that stuff? Is it just noise or just kind of like interesting information you could potentially draw a trend from? How do you view that?

54:21Dr. Franco Impellizzeri:I have to be careful how I answer to this question. We have our legal team on retainer. We're good. Don't worry about it. It's fine. Yeah. No, I mean, there's of course, there is a commercial interest behind some metrics.

54:40Dr. Franco Impellizzeri:So it's not necessarily they can have, these metrics can be solid in terms of science. and even when there are published papers, nowadays it's not enough to have something published somewhere. More or less you can publish everything nowadays. And so you need to be, and this is complicating the area a lot, people need to be good enough to understand whether something they're reading or something that companies use to support their methods are actually solid from a scientific and robust enough from a scientific perspective which is very very complicated and this is why i complain with some colleagues because the way we communicate now science is different than 20 years ago 20 years ago science and the research was basically a niche area only researchers um access this kind of information and And now these information are out there, everyone can access, can read, and you know that in any area, they mention an article on PAMED, sometimes they mention articles on predatory journals that they don't even know is a predatory journal.

55:54Dr. Franco Impellizzeri:So the responsibility of scientists nowadays is completely different. So when you write something, especially for example in abstract, we need to understand that people may just read the title and the abstract, sometimes just the title. So if you use a catchy title, but the title is misleading, this is problematic because you are popularizing a concept that may be wrong. Maybe in the discussion you wrote, okay, these are the limitations, but people don't read that. So this is a responsibility we have. And even if I understand that you can have more traction on social media with some titles or strong ups, most of the time, the results are over-interpreted or oversold.

56:41Dr. Franco Impellizzeri:So this is one of the problems. These metrics that are created by companies are most of the time are instruments to be competitive on the market. So this can buy us, of course, everything they say about this metric. So you can't rely on what the companies are telling you. It's like to ask a chef if they cook well. Of course, they will tell you, yeah, I'm cooking well. So you can't rely on what they say. You have to use your intuition and your capacity to critically examine the information they are telling you. First of all, if it's too good, it's unlikely true because it's not that easy. This area is plenty of uncertainty.

57:33Dr. Franco Impellizzeri:And the reason why some metrics or some measures got traction is because they give you what you want. And what you want is something that decreases your uncertainty. because we cope very bad with uncertainty. And after a while, we create this world of the illusion of control, the illusion that we are controlling the process. No, you are not controlling the process. This is outside our reach. We can try to control the process, which is different than controlling the process. And training is plenty of external factors that can influence how things are going. So as a coach, you are controlling an aspect of the life of athletes, but they have a lot of other things going on around that you don't have, sometimes you don't even know what is going, what they are doing when they are at home.

58:27Dr. Franco Impellizzeri:In some team sports, professional athletes, for example, in football courts, are monitored during training, these kind of things, but they have a personal trainer at home, and no one actually is aware of what they are doing with this personal trainer. So the monitoring that you are conducting on the field with the club doesn't consider an important aspect of the training, which is what these athletes are doing outside the facility. So there are all these things. And after, you may want to develop a prediction model to understand if the injury is, but you don't have all the information. so there are measures, I don't want to cite them but there are measures that in my opinion are absolutely bullshit that are very commonly used and the reason why I'm saying this is because people focus on the numbers and most of the time they miss the meaning of the numbers I give you again the example of the acute chronic workload ratio.

59:40Dr. Franco Impellizzeri:When they show me the IOC model with the sweet spot, all these kinds of things, I was the first time I saw that model. I said, well, but based on this model, if they recover, they increase the injury risk. And this doesn't make any sense. And when I start to explain this to my colleagues, and they say, oh yeah, you're right. So what I want to say is that they were focused so much on these numbers 0.3, 0.5, 1.2, that they miss the meaning of the number because they said 0.5 means that you are training half of the accumulated, the average previous four weeks volume or whatever you're using. So basically you are recovering.

1:00:26Dr. Franco Impellizzeri:So after a recovering week, you are telling me that this is dangerous because they increased the injury risk. But it doesn't make any sense. If they are tired, let's say, and they're fatigued, I give them a week of recovery with a low intensity and so on, you're telling me this is bad, this is risky. It doesn't make any sense. And when I start to mention this, people start to realize there was something wrong in this model. And this is the other point I always make also with my students. Now people are saying, ah, because you know a bit more of statistics, so you spot some errors. And no, actually, that's absolutely not true.

1:01:04Dr. Franco Impellizzeri:So the statistical study was the last I did. But initially, my concerns were because just looking at the numbers and what the model was saying, there were things that didn't sound right. So I just used logic in my coaching experience. And that's why I was really disappointed with some coaches because I said, look, you have trained Olympic athletes. and you didn't realize that these concepts are unreasonable, at least. They don't make sense. So this is just to say that you can, even if you are not a scientist, but you have a critical mind, you can spot some inconsistencies in some of these metrics or in the justification.

1:01:52Dr. Franco Impellizzeri:So using logic can be very helpful to spot that or to smell that there's something wrong. And this means that you have to pick those majors with some grain of salt and not rely on them too much. Yeah. I think as a coach, we want one of these models to be so true because it would make our jobs so much easier. Like we have this black box of like all your tools, right? This is how I organize training. And then you're trying to – there's some art in applying that to the individual. but only if it was more formulaic could you be like i feel very confident that what i'm doing is likely to work again predicting the future it's super hard but we're like look i got numbers this model works and it's like uh yeah it actually at face value you just look at a little bit sideways and you're like maybe this model's got some holes in it not quite there at this holy grail of like yeah yeah look you put an x you're gonna get out on y and and and that's how it goes unfortunately.

1:02:54Dr. Franco Impellizzeri:Yeah, that's very complicated. And besides the nowadays with machine learning, artificial intelligence, LLM, all these kinds of things is becoming even more complicated, but there's no, I was speaking with a friend and he was using some meat and I said, look, they don't work you're wasting your time and I realized that it was too uncomfortable with these uncertain so at some point we have a very good relation so I was very direct and straight and said look the this is the job the coaching is plenty of uncertainty if you cannot cope psychologically with that maybe it's better you change job because you have only two options one is accept the uncertainty and you live with that, or you start to create dogmas, because dogmas are the only thing that can decrease your uncertainty to make you more comfortable with the situation.

1:03:56Dr. Franco Impellizzeri:So these are the two opposite. Of course, there may be some gray, but people tend to polarize in these two extremes. People that accept the uncertainty and people that try to create their own world, ideal world, where they think they have this illusion of control. They have this control, but in reality it's an illusion. Tell you what, there's a lot of money in that dogma stuff though. Like, oh, this is my proprietary method. I am certain. It's concrete. It's binary. And I'll sell it to you. Yeah, but they do their job. They have a company, so I don't blame them. I mean, they are trying to sell something.

1:04:38Dr. Franco Impellizzeri:It's like when you go to buy a cloth, they tell you that this is the best style and whatever. They are doing their job. So it's our job. It's up to us to be strong enough and critical enough to understand what is reasonable, what is plausible, and what is acceptable. And in the end of the day, it's always a risk-benefit analysis. and whatever you do, there is a risk and there is a potential benefit. You have to balance these two. And this is very arbitrary because the same situation can be perceived in a different way. So there are risks that I'm willing to take and maybe you don't, you don't want.

1:05:22Dr. Franco Impellizzeri:And the other way around, there are other situations in which you think that the benefit may be much higher than the risk. But this depends on the context. so and you were mentioning power lifting in this sport you have to train smart absolutely but you have to train a lot you can't train you know you you can't cut the the training half because this is you read a study that is showing you that you decrease the risk of injuries over training this kind of things you can do that i mean you don't work yeah it's not going to work so yeah it's it's not easy of course it is absolutely not easy and and besides it depends a lot on on the talent you have in front of you because i train uh i had the first marathon runners i trained and they had zero experience uh this runner won the marathon and i i never thought i was a good trainer i just thought oh it's so strong it's so talented that even with my shitty training i was able to yeah because i had to look to my trainer yeah that's so awful and especially recently i had the look i said wow that the talent of that guy was so so big that overcame all my rubbish training oh yeah no i had a real life like run-in with something like this I put out programs for free for over a decade now, right?

1:06:54So if you look back to 15 years ago, maybe some of my first programs, it's not that they're bad. I don't know that there's a really bad program. Just maybe good and less good and maybe more effective, less effective, and obviously it depends on the individual. But in any case, I've been training my ass off for a long time. And to your point earlier about being a powerlifter, yeah, you do have to train a lot. And now as a master's lifter, everyone's telling me, you've got to train less. Come on, you're 40 now. You've got to take it down a notch. I'm like, look, I got all this training history behind me.

1:07:21If I train less, I'm going to get worse. I got to train more or, you know, figure out ways to keep getting stronger. In any case, what I'm doing now, I believe in my heart of hearts to at least be the best training I can possibly come up with. Otherwise, I wouldn't do it. This guy, same age, been training half the time I have on one of my programs from like 15 years ago, shows up at a meet, kicks my ass. And I'm like, how does this guy – he just must be physically, mentally gifted far beyond the skills that I have to deal with my shitty training. Anyway, yeah, so it's kind of a similar thing.

1:07:59Dr. Franco Impellizzeri:That's – the individual response is there. Besides, the other point is that people don't understand that research normally provides you the average response in the population. They don't provide you the individual responses. And you don't know exactly how people may respond. And probably you are familiar with the idea of responder and non-responder. That's very tough because normally what you do, what people do, is you try a training with an athlete. For some reason, they don't respond well, or you think they are not responding. And you say, well, it doesn't work. that's maybe not the case because there is a lot of variability in the responses even in the same individual so normally what they say before giving up give another try because you never know that the second time it can work because the way you have to read research is always in terms of average responses in the population so you know if you have 10 athletes on average they may respond in that way like in the study but on average you don't know who is responding more than the others and you have just to try and you try the only way to try to repeat the same training more than once to have to be confident that it may be a non-responder yeah the analogy i use is like if you were coaching youth uh athletes right you or you were like their guidance counselor for example and they were like should i play basketball and you're like absolutely you should try basketball they're like Should I play golf?

1:09:37Absolutely. You should try golf. You should try all of these things, right? But giving up on a training program or intervention after, you know, six weeks, eight weeks, 10 weeks, because it didn't work for you is like telling that little kid after a little brush with golf and they weren't very good at it to say, you know what? Golf's not for you. And it's like, well, look, they could come back a few months later and maybe they're the next Tiger Woods, right? Or, you know, was it Cameron Young or whoever? Okay, whoever. So, yeah, it's – yeah, the analogy holds up. I've got two questions left for you.

1:10:10So the first one, this is like a dystopian future, all right, a little sci-fi thing for you. In a perfect world, I suppose that we'd have like known training load targets or target ranges for specific goals at sports and levels of advancement within that sport, for example. Are there any examples of like that happening right now or maybe like training load mandates in sport? The only thing I'm familiar with, and this is not really the same, but it's like in MotoGP, for example, there's a limit on how much time you can spend practicing during the season. They're like, look, you can spend this much money and you got this much time, this many training or practice sessions.

1:10:50Otherwise, the risk of them crashing their brains out and not showing up on grid gets too high. Is that sort of thing happening anywhere else in sport right now?

1:10:59Dr. Franco Impellizzeri:Yeah, I mean, there are, yes, there are some federations that suggest, especially for academies, they, it's not mandatory. these are recommendations. There are some limits in the time they should be exposed, for example, to headings, because now there is this problem of concussion. So there are some rules, but these rules are more precautionary strategy. even if there's not a lot of solid evidence that above or below can be dangerous. I think it's reasonable sometimes to say, okay, we don't know exactly, but let's keep it under control in some way. So it's more the kind of approach that is used with these guidelines.

1:12:03Dr. Franco Impellizzeri:but yeah, there are, especially for academies and I say for junior athletes, there are some limitations. Whether these limitations are really useful or evidence-based, I don't think so, to be honest. So it's very likely that these limits may be good for some, maybe too low for others and too high for other athletes. But in general, it makes sense that if the dangers are not negligible, that you want to introduce some sort of control. But in the future, I mean, from a theoretical, you were talking about an hypothetical future. In everything, prediction, understanding, in theory, is doable. in theory.

1:13:02Dr. Franco Impellizzeri:But we don't have the instrument to do that, even with this machine learning or this kind of things. At the moment, we don't have the instrument. One problem is to have the measures that allow us to make these predictions. And by measure, I mean the measure of various factors that can influence the outcome of the process. Now, they are wearable. So maybe in the future there will be some new wearables that allow to collect all this information in order to be elaborated. So in theory, this can be done, like prediction of injuries can be done. In practice, we are not there, but we are very, very far from there.

1:13:44Dr. Franco Impellizzeri:It's like personalized medicine. that's a hot topic but I know some very among the best statisticians in the world saying that it's an illusion not because it's not doable it's because we don't have at the moment the resources to do that because it's very they require a lot of data a lot of elaboration running trials to understand the response is too big so on paper it's doable but we cannot with the resources we have we cannot do that and I use this example because when I say look in medicine they are trying to go in that direction they are struggling and they have billions behind in sport that we are a niche we are so small it seems to me unlikely that we can do what others feel with 1000 times our resources couldn't But they are trying to go there, you know, using genetic markers, all these kind of things.

1:14:50Dr. Franco Impellizzeri:But still, it's very difficult. But I'm saying that because statisticians said it's possible, but we don't have the resources to do that at the moment. So everything we said, predicting injury, understanding individual responses, all these kind of things, is doable in theory. but we don't have the resources to do that and I don't think in the next 10 or 20 years we go 20 years I don't know but in the next 10 years I don't see this possible I know this will disappoint people especially companies but that's oh yeah as I told you I'm happy to have a open conversation with anyone because in the end of the day that's my opinion but if you have a different opinion you have and we are talking about science we need also to show some some evidence and i don't think there are yeah i do think that all of these questions are theoretically answerable but to your point yeah uh whether it's a technology limitation resource limitation both or just you know we don't even know what to measure like there are multiple gaps in what we know right now uh that would limit that but i'm just thinking like all right what is 20 years 50 years, 100 years from now, you know, little Timmy wants to go out for football or whatever.

1:16:09You put him on a conveyor belt. They swab the inside of his cheek and, you know, do a pan scan of him. And they're like, this guy needs X for his training load, you know, based on what we know now. That would be cool. I think that would be cool.

1:16:21Dr. Franco Impellizzeri:That would be cool, but there will be no coach anymore because you can do it with an algorithm. You don't need anyone. And perhaps in this dystopian future, everybody ends up being the same level of good. at their sport, right? And then there are no winners and losers anymore. It's all draws. And then, yeah, then we're really in a pickle. But yeah, just the thought. Okay, this is the last question. And I know this is a recent paper. It doesn't directly have to do with measuring training load or maybe a more practical example. The recent review, I think it's from last year, was on skill acquisition in sport.

1:16:57And for listeners who haven't read this paper, I put in the show notes, a good chunk of the papers are on golf as a golfer. I liked that. But But the majority of studies were in inexperienced athletes, inexperienced subjects, and there was only like short-term follow-up for most of them. So a little less excited about that. But limitations to the methodology and the included subjects aside, how does the concept of training load intersect with or inform the process of like acquiring and mastering sports-related skills?

1:17:28Dr. Franco Impellizzeri:That's actually – there is a good friend of mine. His name is Joab Fransen, who is an expert in skill acquisition. And he is also very critical about the area. I mean, he has a very critical approach. You know, there are different theories about the volume of practice that you need to master something, with some thinking that the more you do, the better, and some thinking that's not necessarily true. I don't think... I see both points. I think there are sports in which practice is important, and the more you do, the better. I have no doubts about that. Golf may be one of these, to be honest. Yes, super high skill or whatever.

1:18:16Yeah.

1:18:17Dr. Franco Impellizzeri:Yeah, exactly. But from a monitoring perspective, we come back as before. We don't know how much is enough for each individual. So the only thing you can do is to monitor the practice based on what is your philosophy of coaching or what you think is useful. But from that, I'm very, I think quality is important, but I still think that quantity has an important role in any sport. Now people move towards doing less and better, but it depends less than what. If it's less than, let's say, moderate volume of training, I don't think this is going to work. But less is better if the quality is good because if you are a high-level athlete, you are already training a lot.

1:19:17Dr. Franco Impellizzeri:So in that situation, even increasing just a bit may be the thing that induce overtraining, overreaching or this kind of thing. So when you are at that level training a bit less and with better quality or optimizing what you're doing actually can make the difference. But at that level but I think at that level very few athletes are at that level. Most of the athletes are even good athletes are still in an area where quantity matters. It's not the same thing. It's like when we discussed about injury prevention, improving strength in different populations. Yeah, improving strength, I'm sure it can be helpful for several reasons, but improving strength in someone that is already strong is different than improving strength in someone that is, say, weak.

1:20:15Dr. Franco Impellizzeri:Yeah, different. Yeah. First of all, it's much more difficult to improve strength if someone is already strong. And second, the effects may be different, at least in terms of magnitude. So when we generalize finding from the studies, we need also to think about the population. Besides, I'm not saying that you cannot apply studies in other populations, in your population, but the entity of the changes may be much different. so you can maybe have improvement that are negligible or you cannot even measure this improvement in some populations. But in general, from a skill acquisition perspective, I still think that the quantity is important.

1:20:59Dr. Franco Impellizzeri:Also because the quality is a very weird concept. It's not easy to understand because quality movements means to have a standard, while there may be a lot of individual differences depending on the individual characteristics. So it's much more difficult to understand, to have a reference standard for technique or whatever. Yeah. Well, people say that all the time. They're like, well, look, your perfect practice makes perfect. And so, for example, in powerlifting, which is the, we charitably call it a sport, and I happen to participate in that activity. They're like, well, look, you got to have perfect squat form and technique.

1:21:38And I'm like, well, what is that? I mean, we're based on the sport. There are some constraints to the squat. For example, the bar has to be on your back. You have to get below parallel and you have to start from a locked out position, right? And then rack it under your own power. But there are many variations within that. And further, if you're saying, well, I'm not talking about that. I'm just saying in your training, you have to squat what's perfect for you. And I'm like, well, what if I happen to get out of position on the platform? Isn't it nice to have some additional strategies to try to overcome the load so I make the – there's – to your point, there's probably some benefit to like just getting exposed more and more often so you have – you're practicing, right?

1:22:17But it doesn't have to be this rigid model of like only this way can you practice. I think that's...

1:22:23Dr. Franco Impellizzeri:Well, that's actually a very good example because powerlifting, weightlifting is where I see a lot of, a bit of a mess, meaning that... No, because I have very, actually very good friends who are coaches and also were international athletes. And if you speak with them or you speak with other, say, coaches at lower level, these are the one higher level are the one that are more aware about individual differences. They don't have the fixation with the perfect technique. So they allow for some, let's say, individual adjustments much more than the lower level coaches and athletes. and I agree with them because in the end of the day you may have an idea of technique but this can be adjusted by the different individual that they tend to adapt to their characteristics while when you speak with others they I mean I have seen videos of world champions and posted on social media and tons of comments about the bad technique all these kind of things I said what the fuck.

1:23:37Dr. Franco Impellizzeri:I mean, if this person won the world championship, they won, it's effective because they have... By definition. Yeah, it can be better, but still it's one of the best in the world. So eventually this technique is good for the performance because in the end of the day, what people don't understand is that powerlifting, weightlifting is a performance-based sport. So So in the end of the day, what matters is how much load you lift. So the more, the better. So any strategy that allows these athletes to lift more than others, allows them to win or to compete at a high level. So they are not evaluated based on the technique.

1:24:27Dr. Franco Impellizzeri:It's not the gymnastic, you know, with the referees saying, oh, this is good, this is bad. in the end of the day, and this is why I like, because it's a very pragmatic sport. I mean, they have to lift as much as they can. And actually, in theory, they can use, okay, within some constraint, other variations, any variations of technique. So it's okay. But this is the fixation with these, you know, small changes, the debate about the Chinese and the technique of the Chinese. Well, another point, and I don't want to take too much time, but something people don't understand is that elite sport, we are working with the survivors.

1:25:07Dr. Franco Impellizzeri:So the survival bias is very important, and you find this problem a lot also in studies. When you compare elite athletes with other people, basically you are comparing orange with apples because they are a selection. So you don't know if they are using a technique that is good for them. You cannot generalize to other individuals because the one that you see at the top of the pyramid are the ones that survived over the years. So it's possible that the technique they are using have destroyed thousands of other people and they are the only ones that can cope with that specific technique that allowed them to live more than others.

1:25:49Dr. Franco Impellizzeri:So these kind of comparisons are very difficult to do and I normally warn people, don't compare elite with others because the elite are a very selected population. And it's very likely that they are the survivor or also bad techniques. Hey, yeah, present company included. Well, because people, they do ask, they're like, hey, look, should I just do your program? Why don't you just publish the program you're running? I'll buy it so I can run it. And I'm like, financial motivations aside, I'm not sure that what I'm doing is going to work for you. And then the reason why I've been able to persist so long in this sport and achieve some modicum of success is probably, you know, related to things that unique things that make me, me.

1:26:38And if you don't have those same unique characteristics, I would just be setting you up for failure. And I can't, I can't, I can't abide that. So yeah, it's, it's like the other people that I've been competing with for these 15 years, we are far different than the people who started competing. They did it for two years and then burnt out. And so if I was creating my prototypical power lifter, who's going to go be a world beater and persist at the top of sport for years. Yep, they'd respond awesome to resistance training. They'd gain a lot of muscle mass and a lot of strength. Yep, they'd have a really robust musculoskeletal system to start with, thick joints, everything else.

1:27:11They'd have a great work ethic, and they'd also be super resistant to injury because, like, you need all of those things to survive. And it's like the strongest potential power lift ever, you know, it's going to be some mix of that. But there's somebody who maybe is potentially – their max volitional isometric contractive force is higher, but they can't sustain the training, and so they can't ever sustain that and be at the top of sports.

1:27:37Dr. Franco Impellizzeri:Yeah, I completely agree. But training a lot more and all these kind of things should be seen from this perspective. So in the context of uncertainty, individual responses, all these kind of things. So the only thing you can do is to monitor training just to understand whether your program is going in the direction that you plan. And that's why what you measure depends on your training program. There's not such a gold measure. It's up to you. And people don't accept that. They want to measure. And every time they ask me, what do I use? I don't know what you can use. I mean, there are tons of measures.

1:28:20Dr. Franco Impellizzeri:Some are good, some are maybe not that good, but it really depends. If you have designed your training based on time, you measure time. Because there are two different kinds of discussions. One is about how we monitor training and the other is how we plan a training. So if I agree with the training, because when I work with teams and sometimes I provide what I think is better to monitor what they are doing, it doesn't mean that I agree with what they are doing. Yeah, yeah. I'm just saying, okay, if you want to do that, it's your job. You are paid for that. You are fired if you fail. So my job is to help you in doing what you want to do without questioning anything.

1:29:01Dr. Franco Impellizzeri:If you ask me an opinion, I can provide my opinion, what I would do or why I don't agree. But in the end of the day, it's a coach decision. So to summarize, I trust coaches and I work around coaches. They are the one training athletes. And as a sports scientist, I need to help you. The level of help depends on what kind of help you want from me. If it's just monitoring or you want to discuss about the strategy. You may say, I'm doing this because of these reasons. I can say, okay, these reasons make sense. These are actually not really supported by evidence. So maybe it works, but not for that reason, for example.

1:29:47Dr. Franco Impellizzeri:And besides, I much prefer very elaborated and solid reasoning than the use of weak evidence. So that's always my – where I separate from a practical perspective the people I trust and the people I don't trust in terms of coaching. I was going to ask you what's the one thing you want people to take away from this, and you just did it. You're a natural. Like if you don't have a podcast yet, maybe consider just all the extra time that you have. I'm a boomer for these things. And I have this setup because of the manipulation of my sons to buy them all the equipment. But yeah. No, I know that most of the time people don't have from me the answers they want.

1:30:38Dr. Franco Impellizzeri:And I can't give the answer they want. I'm sorry. Yeah, I was hoping you were going to tell me how to get stronger, but it turns out I know less now than I started. Yeah, I mean, I can tell you have to train more. Yeah, hey, I like that. I'm here for that. I'm here for that. As long as I get to live more. If you can train more and you survive, you may be stronger. Truer words, never spoken. I like that. Where can people find you? I know, like, I'm going to list, there's a Google Scholar page with all of your publications, so I'll link that. Is there any way for people to interface with you on social media?

1:31:17Are you a lurcher? Do you post? What do you do?

1:31:21Dr. Franco Impellizzeri:I'm on social media. I'm on X. I'm on Blue Sky. I'm on social media. But in the last years, I moved a bit away from social media.

1:31:35Dr. Franco Impellizzeri:I read posts. I lurk posts. I don't interact as much as in the past because I'm quite, I am Italian, so sometimes I cannot control myself. So I decide to move a bit away and joke apart also because I found recently it was a bit too toxic as an environment. So I read it just to have an idea what is happening, but I find more and more difficult to interact because I'm very critical, but I like to have this kind of conversation, to have an intellectual opponent. Most of my co-authors and my colleagues are intellectual opponents. But this kind of interaction is becoming more and more difficult and people get offended very easily.

1:32:26Dr. Franco Impellizzeri:So just to say, I'm on social media. I don't interact a lot, but I read comments and posts and these kind of things. Well, if you're out there and you're commenting on training load, just know that Dr. Impelizuri, he's reading your stuff. He's kind of like Santa Claus. He sees you when you've been naughty, sees when you've been nice. Yeah, I'll link all of his stuff in the show notes. But really, thank you so much for joining me. Thank you for having me and for the invitation. Thank you very much.