The 10,000 hours vs genetic debate, and correcting Prof Ericsson’s mistruths
So last night, I was (un)fortunate enough to be involved in a radio debate with Prof Anders Ericsson on the concept of talent vs training. For those who don’t know, Ericsson is the father of the 10,000 hour concept, where he prescribes that ANY individual can become an elite athlete if they engage in the required hours of deliberate practice. He sets that number at 10,000 hours, which is really more marketing than it is science, and I had the chance to “debate” this on air last night.
Unfortunately, the debate ended before I was able to adequately respond to some of Ericsson’s claims, and so this is a post to do just that – respond, put the sports science side of the debate across. I address the article to Ericsson somewhat tongue-in-cheek, and I don’t mean to appoint myself on behalf of sports science, but the truth is that someone has to point out that the books, the popular media, and Ericsson are misrepresenting the evidence (either deliberately or ignorantly). And besides, Ericsson did ask in the radio interview (see below).
The debate was a glorious seven minutes long (I was told it would be much longer), and it involved two opportunities for Ericsson to state his case, and two for me to try to explain the physiology of elite athletes. Going in, I was under the impression we would debate the points, but that never really happened, mostly because I didn’t think it was going to be cut short at 7 minutes.
You can listen to the podcast here. Just click “Listen Now”. The interview portion starts at 9:00, as the section before is an interview with Chrissie Wellington (this provides some context for some of my comments in my first response).
A stunned reaction
I was, throughout the interview, stunned at what I was hearing. And it’s not as though I’m new to this particular debate – I’ve recently written two review articles on this topic with a colleague of mine (a geneticist, because unlike Anders Ericsson, I don’t like the idea of commenting about a field that I’m not an expert in – he’s a psychologist, but he was throwing physiology around with abandon, as you’ll hear and read later). These articles will be published in peer reviewed journals later this year, I’ll let you know when. There are also the two articles (PART I and PART II) that I wrote here on The Science of Sport last year, and then I presented on this at the UK Sports and Exercise Medicine conference in London last November.
I have also read the books – Bounce, Outliers, so in theory, I’ve heard it before. But I was just absolutely stunned that Ericsson was saying some of the things he did – you can hear this in my reaction in the podcast as I start my response to both questions! What he says is just ludicrous, empty and baseless, and I can only think he’s misinformed, or has some other agenda to push. Maybe he is writing a book…
Truth is, you don’t even need research, you just need common sense and a tiny bit of experience with elite athletes in training groups. For example, if any of you have ever run with a training group, you have seen and felt the reality of “individual responses” to training – you know that 1,000 hours of identical training will not produce an identical result in ten different people. There are examples all over the place that show that practice is not sufficient for elite performance, and there are as many examples of athletes who have succeeded on far, far less than this (there are even cases in chess, where, dare I say it, performance is a little less complex because there’s no risk of overtraining, injury, etc).
Also, Ericsson’s theory that it is the training done during the adolescent years that matters is not only wrong (look how many talented young athletes fail at senior level despite accumulating far more hours than their peers by the age of 18, and how many endurance athletes only take up the sport in their 20s and become world class in a few years despite zero training when adolescents), it’s also very irresponsible, because it compels parents, teachers and coaches to start training young athletes too soon and that’s detrimental to the person (see Cote et al for review).
The statements – no scientific evidence showing that genes or physiology limit performance?
In his second response in the podcast, Ericsson makes the following statement in response to my argument that the scientific evidence suggests without doubt that elite athletes and champions are BORN AND MADE:
“I would argue here, and reading all the reviews, and we’ve had reviews where every scientist from the exercise physiology field and sports psychology. And I find it kind of remarkable that Ross is making these claims because I’ve never seen them made in print in any peer-reviewed publication” – 13:55 in the podcast
He goes on to say the following:
“I have to say that I’d be very interested to see Ross finding any scientific studies that support the kind of claims that he was making at the beginning of the programme” – 15:01 in the podcast
Outside the scope of knowledge – don’t tread where you shouldn’t unless you have a guide
Before I continue, just have to mention that I have provided a list of peer reviewed publications as references at the end of this post – they are both review articles (Ericsson made the claim that he’s read ALL the reviews – clearly he’s missed these ones), and they are original research studies that show the importance of genetic factors and physiological variability to training. Clearly, he’s never read these either. I’d excuse this on the basis that Anders Ericsson is a psychologist, so one would not expect him to have a firm grasp of sports science, performance, physiology and the genetic literature, but the fact of the matter is that he’s making claims in those fields, so therefore it’s fair-game to challenge his knowledge and understanding of the literature and the sports science performance fields.
And I must just make this point – I don’t for a second think we should create intellectual “silos” where you can ONLY comment on your field. I think that would be foolish because it’s the process of thinking, the scientific approach to a question that matters more than the actual content. And I’d like to think that the biggest advances in our understanding often come from thinking outside the “constraints” of what we know, and by integrating research from different fields by different experts.
In other words, someone may be trained as a physiologist, but it’s their application of the scientific approach, allied to some small physiological understanding, that may allow them to contribute to the field of biomechanics of barefoot running, for example. Key to this are two things: a) you must be dilligent about doing your research, and b) find someone who IS an expert to assist. That’s why when in writing review articles on talent vs training and elite performance, I partnered with a geneticist (Malcolm Collins) who does understand the field at the depth that is required to put scientific statements out there. Similarly, I’m now doing barefoot running research, where my interest is the physiology, but we have a team that includes an engineer and biomechanist, so that I don’t have to tread where I’m not capable.
Responding to Ericsson – one example of “limited” physiological response to training
In any event, during the debate, I tried to respond to Ericsson, and there are four things that I think are essential to understand here:
- It is true that genetic “proof” has yet to be provided. But elite sporting performance is too complex, and genetic factors too varied to ever “prove” the link Ericsson seems to require. Consider this: height is a pretty straightforward characteristic, and it’s known to be highly heritable (tall parents = tall children). In fact, 80% of the variance in height is known to be genetic. However, studies have found that it takes an astonishing 300,000 genetic variants to account for only 45% of this variance. That’s just height – how much more then would it take to explain something as complex as sports performance?The reality is that the field of genetics is young, and with time, more evidence will emerge. But there’s a massive difference between something being “proven” (where I agree with Ericsson) and saying that it is absent (which is what he implies). Genetic evidence is not absent – most physiological factors that are known to limit performance have been associated with genes (including injury risk, aerobic capacity, muscle fiber type), and others can be easily related to heritable factors (think height for basketball, limb proportion, bone mass etc). When Ericsson suggests there is no evidence, it is because he is ignorant of the evidence.
- Ericsson’s own work disproves his theory – his studies have tried to explain performance level as a function of training, yet research he has been involved in shows that only a very small part of performance can be explained by practice. Only 28% of the variance darts performance is explained by the number of hours practiced! That’s astonishingly low, and it means that time spent in practice is a very poor predictor for performance. The question you should be asking is what accounts for the other 72%, and could some of it be innate? It’s definitely enough to throw out the deliberate practice, 10,000 hour theory, because Ericsson is clearly predicting that most (or all, in some of his articles) of performance is explained by training.
- You cannot prove that practice is necessary AND sufficient to produce champions or elite performers based on retrospective studies. They’re weak, because there are so many other ways to explain the findings. For example, Ericsson’s famous violin study showed that the expert performers did the most practice, and he concluded that the practice turned them into experts. However, it’s equally possible, in this study design anyway, that the children with the innate violin ability were encouraged by others and their own success to practice more. Retrospective studies are poor ways to show that practice makes perfect. You have to do prospective studies.
- Prospective studies have been done. Most notably, Bouchard published a study in 2011 (reference below) in which he found that the response in VO2max (a measure of aerobic capacity and adaptation to training, and ultimately performance) of a large cross-section of the population to a standardized training programme was enormously varied. Some individuals improved by less than 5%, others improve by 30%. And here’s the key point – it is possible, using genetic techniques, to identify which genetic polymorphisms (think of them as variants of genes) are responsible for this huge difference. It turns out that Bouchard’s work has provided some pretty important findings:
- About 50% of an individual’s starting VO2max and 50% of the “trainability” in VO2max is heritable
- 21 Genetic polymorphisms have been associated with 50% of the training response to VO2max
- If a person carries NINE OR FEWER of these genetic variants, then they are low responders and improve VO2max by only 200 ml/min.
- If a person carries NINETEEN OR MORE of these variants, then they are high responders and improve VO2max by over 600 ml/min
In other words, genetic factors very clearly impact on what we start with, they impact on how we adapt to training, and therefore, by extension, they impact on where we get to. Our physiology has a ceiling, and it is in part, genetically determined. This is clear for VO2max, and it’s clear for other factors that are known to affect performance. Skeletal muscle, for example, is known to be BOTH heritable and trainable. Running economy differs enormously between individuals as a function of factors such as height, limb proportions, muscle mass, and other factors that are known to be genetically determined. And so unless you have the right skeletal structure, height, limb proportions, you cannot have the running economy required to run a 2:08 marathon. It’s physiology, limiting performance, and related to factors that we are born with. To deny this is to say that the world is flat when you are staring out of a spaceship window at the globe.
Further, as one of you commented on Facebook yesterday, biomechanical factors such as the muscle’s moment arm exert huge effects on performance, and so characteristics that we are born with determine the level of performance that we can attain. I would point out the most obvious example of this is basketball, but there are countless others.
A pointless polarization of the debate
Ultimately, however, the idea that elite sporting performance can be explained by one factor is foolish. That’s why when Ericsson makes the claims he does, in the field of physiology, it’s so absurd, and potentially damaging because people believe it at face value, and they implement sports systems and strategies that buy into this flawed concept. It’s quite clear, from what we observe in athletes, what we study in laboratories, what we know from geneticists, that there is a significant contribution of all kinds of factors to performance. Physiology matters, but so does practice. Psychological factors are crucial, but so too are financial and economic considerations.
The dominance of Kenyan runners, for example, will never be found to be due to ONE factor. Those who are looking solely at genes are doomed to failure, but so are those who want to say that it’s purely an altitude, diet, socio-economic, lifestyle, or incentive-driven phenomenon. All these factors contribute, and the environment interacts with the genes to produce a champion. I’ve said this before, but training should be defined as the realization of genetic potential.
Every single person improves as a result of training – some, as Bouchard has shown, improve by very little in a variable like aerobic capacity. Perhaps they are better suited to skill-based sports. Some improve enormously, and those who do are more suited to endurance sport. Then there is injury – this is vital and completely overlooked. We know that certain genes are associated with different performance characteristics, and there are genes that are associated with injury. Some people will never even reach 10,000 hours because they are susceptible to injury at five hours per week of training and cannot do more – they’d need 40 years to get good enough if that’s all it took.
So the point I’d like to conclude with, before I list some more points for Anders Ericsson to consider, is that we should not polarize the debate. We should recognize that there are many paths to elite performance, and that a one-size or one-number fits all approach is foolish. We should learn what we can from those who succeed, including that they are dedicated and practice a lot, which is obvious. And we should learn why people fail. And we should avoid generalizations and simplifications that help us sell books to motivate people.
Training is the realization of genetic potential – practically, that means that every single one of you reading this, discussing this, can improve through training. That’s the motivation. But will we all become Olympic caliber athletes in any sport we choose? Keep dreaming. The world is not flat, Prof Ericsson. Please stop telling people it is…