Education for runners and endurance athletes. Learn to train smart, run fast, and be strong.

These articles are free.
Please help keep them alive by buying me a beer:

Is it genes or environment? You gotta nurture your nature for athletic success.

Thomas Solomon PhD.

21^st December 2019

The “nature versus nurture” — genes versus environment — debate bounces back into the limelight from time to time. In this article, I explain the background behind the persistence of this debate and ultimately describe why it is an irrational discussion point. Disclaimer: This article jumps into the depths of science. Yet, those depths are disentangled with the use of violins, chess, and obstacle-racing.

Please retweet or share this article with anyone who will find it educational:

Reading time ~23-mins (4500-words)
Or listen to the Podcast version.

I have been asked the question “is it nature or nurture?” several times. To begin, I will boldly fire my mind-bullet in your direction:

Nature (i.e. genetically-determined talent) is 100% important until nurture (i.e. training, opportunity, motivation, and good choices) is introduced and subsequently promoted to being 100% important.

In 1993, the psychologist Anders Ericsson published his “deliberate practice framework”, describing that “individual differences, even among elite performers, are closely related to assessed amounts of deliberate practice”. This notion that more time spent practising ones’ craft eventually leads to greatness was subsequently made widespread in popular culture books like Bounce by Matthew Syed and Outliers by Malcolm Gladwell, who coined the now-famous “10,000 hours rule” (i.e. with 10 000 hours of deliberate practice, one becomes an expert in anything). The media ran with this influential sentiment, shoe-horning observations made in musicians on to outcomes in elite athletic performance, proclaiming that 10,000 hours of deliberate practice (i.e. nurture) is all it takes to become a champion. As of December 2019, Ericsson’s original paper has been cited over 10,000 times, a value that is considerably coincidental.

LeBron James. Lionel Messi. Serena Williams. Roger Federer. Usain Bolt. Janja Garnbret. Tiger Woods. Lyndsey Vonn. Lasha Talakhadze. Paula Radcliffe. Kílian Jornet. Simone Biles. Jon Albon. These fine specimens have dominated their respective sports. If 10,000 hours is “all” they needed then one might wonder what separates them from their peers who have “done their time” and are also world-class but just don’t have that edge. Now, if I take you on a journey, I remember the girl in primary school who had a greater dynamometer-measured peak grip force then everyone, including the teacher. I remember the boy in middle school who had a 6-pack despite never exercising. I remember the tennis player at high school who never trained for running but always beat everyone in cross-country races. None of these three anecdotes had “done their time” at that point in their life yet had superior physiological attributes to the rest of us. Furthermore, of these three anecdotes, only the latter subsequently entered the world of high-performance sport, ultimately becoming a 2:25 marathoner. The other two examples meanwhile never pursued an athletic career, one due to apathy, the other because of a spinal injury. Hence, from observing simple anecdotes, talent is quite apparent in our everyday lives while factors like motivation (or lack thereof) and (mis)fortune also raise their heads above the weeds.

What can we learn from nontypical gambits in chess?

In an alternative sporting arena, Magnus Carlsen, a Swedish prodigy, was recently documented in a Netflix movie on his quest to become a chess grandmaster. Given Ericsson’s rule of deliberate practice, Magnus should have accumulated more hours of deliberate practice than the other players in the world rankings, particularly given that he has utterly dominated world chess since 2013. However, as analysed by Gobet and Ereku in 2014, Magnus had then indeed accumulated a large amount of practice but statistically-significantly fewer years of practice than the other players in the top 10 of the world rankings. Without hesitation, I, therefore, ask myself, “Is Magnus talented?”. In the world of chequered boards and ebony-carved kings, which considers him the “Mozart of chess”, this question seems foolish. As shown in the documentary, Magnus was precocious from a young age and could recite impressive lists of facts and, at 13, he became a chess grandmaster, just 5-years after moving his first pawn. In 2013, at just 23, Magnus unleashed his superpower and defeated Viswanathan Anand to win his first World Championship title in classic chess. During his game, he uses an unconventional playbook, choosing not to train with computer simulations or to plan opening moves (gambits) like his peers. Instead, he uses a range of varied moves that typically do not exist in computer models. He, therefore, beautifully demonstrates that deliberate practice is necessary, but not sufficient, for achieving an “elite” level of performance.

What can we learn about training from nontypical gambits in chess? Thomas Solomon at Veohtu..

Photo by Vlad Sargu on Unsplash.

What can we learn from Vivaldi’s Four Seasons violin concerto?

While the story of Magnus Carlsen is simply an anecdote, for the purpose of understanding the “nature vs. nurture” debate, individual observations are VERY important. In his 1993 “deliberate practice framework” paper, Ericsson asked 10 of “the best”, 10 of “the good”, and 10 of the less good (“the teachers”) violin students (mean age 23) at the Music Academy of West Berlin to recall the hours they had spent on practice during their lives. He also asked 10 middle-aged professional violinists (mean age 50) at the Berlin Philharmonic Orchestra and the Radio Symphony Orchestra to recall their hours of practice accumulated up to age 20. This type of retrospective recall over many years is not an ideal evaluation in scientific method; alas, the theoretical framework was built around this study design and Ericsson found that by age 18, violinists labelled as “the best” had accumulated 7410 hours compared to 5301-hours for “the good” and 3420 for “the teachers”, while those who had gone on to become professional accumulated 7336 hours by age 18. The conclusion being that one requires at least 7336 hours to achieve elite status. A problem arises, however, in the interpretation since the paper only presented the mean (the average) values throughout the results, giving the reader no clue about the variance of the data (i.e. an estimate of the spread of individual data points around the average). So, from the point of view of arguing that deliberate practice is a requisite, this paper is essentially useless. From that paper, we cannot know whether there were “teacher” level violinists who practised for 20,000 hours and never achieved greatness, nor can we know whether there were professional level violinists who had achieved their state of excellent from just a few bow strokes here and there.

What can we learn about training from violin playing? Thomas Solomon at Veohtu..

Photo by Michel Catalisano on Unsplash.

Fortunately, Macnamara and colleagues in my old town of Cleveland, Ohio, repeated Ericsson’s work, almost to a T, but with a more refined touch to the data presentation: confidence intervals and data ranges. Science may only be interpreted if its presentation is graced with clarity. Accordingly, they found that by age 18 the 10 “best” violinists had practised, on average, for 8224 hours, with a range of 3978 to 14,664. This value was not statistically different from the “good” violinists who had accumulated 9844 hours of practice, with a range of 3120 to 21,268. Meanwhile, the “less accomplished” players had accumulated statistically less practice time at 4558 hours, with a range of 2522 to 10,972. As you may already have judged, the ranges of values are wildly poignant. In fact, they immediately negate the notion of Ericsson’s “deliberate practice framework” or Gladwell’s 10,000-hour rule. Why? Because among the subjects studied there were elite violinists who only practised for 3978 hours (efficient, huh) as well as less accomplished players and “good students” who accumulated as many as 21,268 hours of practice (super motivated) but never attained the elite status. Again, the deliberate practice was necessary but not sufficient. This notion has even been confirmed in more recent work from Ericsson’s lab in professional darts players. A greater amount of time spent on practice was indeed associated with higher darts averages yet, at best, only 28.1 % of the variance (i.e. the variability in darts averages between people) was explained by deliberate practice (15-years into their career; r=0.53). Despite that, they conclude that “the present study revealed that the single major factor contributing to professional level dart playing performance is deliberate practice”. You might ask yourself what explains the remaining 72% of the variance in expert performance?

Deliberate practice and performance. Anders Ericsson vs. Macnamara, from Thomas Solomon at Veohtu.

Deliberate practice contributes to success but is not exclusive.

I, along with other scientists in the field of rationale science, do not dispute that accumulating deliberate practice is advantageous for achieving success. If you accumulate deliberate practice, i.e. if you train, you tend to improve. Coaches observe that if their athletes train, they tend to get better. Large-scale observations of endurance athletes show that on average, the best athletes have accumulated more training hours — more deliberate practice. And, randomised controlled trials show that training improves performance. With these several lines of evidence, both empirical and scientific, we cannot deny that deliberate practice is important.

In complex skill-based pursuits, including chess and music, perhaps accumulating more time practising the craft is more important than it is for the success of linear physiological pursuits, such as say 100m sprinting. But, the evidence is very clear that deliberate practice is not the sole requirement to realise success. Further evidence for that is provided in a recent meta-analysis showing that accumulated time of deliberate practice accounted for 18% of the variance in sports performance at the sub-elite level while accounting for only 1% of the variance in performance among elite-level athletes. In his 1993 paper, Ericsson wrote “we reject any important role for innate ability”, a bold statement, especially while surely knowing the range of individual values within his sample of subjects. Yet, even as recent as 2012, Ericsson continues to negate the role of innate ability (fast forward to 9-mins of this podcast), even denying that there is any supporting evidence. As a scientist, I typically examine changes in mean (average) values from samples of populations while accounting for variance within the sample. As a coach, I examine the variance or, more specifically, the inter-individual nuances and individual adaptations to stimuli. Any scientist who has conducted an intervention will know of the variation in responses within their sample. This contributes to the overall effect size of their intervention and the effect size is critical for making applied decisions in the field of interest, whether it be biological, medical, economic, or environmental policy. Any coach will acknowledge that individual athletes can have vastly different responses to a common stimulus. Any person who attended school will remember the kid who had an incredible capacity to remember facts during a new class, despite having been exposed to the same material for the same amount of time as everyone else. So, even without rigorous scientific study, we are exposed to examples every day that make it very difficult to “reject any important role for innate ability” i.e. to reject genetically-determined talent.

Gene transcription for runners and obstacle course race athletes from Thomas Solomon.

Genetics, talent, and all that jazz.

Your physiological attributes can only go so far — you will never be as tall as a giraffe, sprint as fast as a cheetah, hold your breath for as long as a blue whale, or run for as long as a husky. This means you have a “ceiling” of performance capacity. Such things are determined in your genes.

You have 20,000 to 25,000 different genes in your DNA; two copies of each, one a gift from your mother and the other from your father. Your genes are transcribed to mRNA which is then translated to 20 different amino acids. These amino acids build proteins. You have at least as many different proteins as you have genes. The proteins are then folded and transported to where they are needed. Functional proteins then help facilitate functional outcomes in your body. This is a vastly remedial version of complex and constantly-occurring processes that are influenced by age, environmental stimuli (nutrition, exercise, stress, illness), and epigenetics (something more bewildering, kind of like the punctuation in your sentences of genetic code). Anyway… Retrospective studies, like those from Ericsson or Macnamara, are not ideal ways to determine the role of deliberate practice in creating an elite performer. Prospective studies are preferred and it is possible to conduct well-controlled prospective studies. While Ericsson argues against a genetic basis for performance, he is ignoring some of the largest and most well-designed prospective genetics studies published to date. One of the most famous is the HERITAGE Family study, which aimed to examine the variability in changes in VO₂max (the gold standard measure of cardiorespiratory fitness) following a standardised exercise training intervention and to examine the genetic basis for the changes. Four-hundred and eighty-one sedentary adults from 98 families were assigned to a standardised training intervention for 20-weeks. The average increase in VO₂max was ~400 ml/min but heterogeneity in responsiveness between people was large; some people gained more than 1000 ml/min, others had little or no improvement, while some worsened. The main outcome of heritability was analysed and 47% of the variance in the VO₂max response to training and up to 58 % of the variance in the ventilatory threshold response to training (you might know this as the lactate threshold) were found to be familial, which means that around half of the changes in cardiorespiratory fitness were explained by heritability and, therefore, genetics.

The HERITAGE study has since produced hundreds of publications, massively advancing our understanding of the genetic basis for physiological performance. There is now a long list of genes and gene variants (known as single nucleotide polymorphisms, SNPs) that are associated with the VO₂max adaptations to training. In fact, about half of the training response is explained by approximately 20 genetic polymorphisms. These genetic aspects are related to many different biological functions in skeletal muscle, cardiac muscle, neurons, blood vessels, etc, and have been confirmed in validation studies of other data sets. It appears that approximately 50% of someone’s baseline VO₂max is familial and that around 50% of the magnitude in the VO₂max response to training is also inheritable.

Naturally, several targeted studies in elite athletes have also been conducted and specific genes/gene variants have been associated with high aerobic capacity, fat-free mass, muscular strength and power, etc. Furthermore, risk for musculoskeletal soft tissue injuries also has a genetic basis, which means that being prone to an injury can also interfere with one’s adaptability to training. In 2009, an update to the Human Gene Map for Performance and Health-Related Fitness Phenotypes showed that 214 autosomal genes (genes not involved in determining your sex) and 18 mitochondrial genes (genes in your energy-producing parts of your cells) had, at that time, been shown to influence fitness and performance. But it is always important to remember that these genetic associations, albeit numerous, do not account for all of the variability in the functional outcome(s) being measured.

Inter-individual heterogeneity in exercise training responses from Thomas Solomon at Veohtu.

Variability between people in the magnitude of the response to the same amount of deliberate practice (i.e. the same amount of training, or nurture) has been documented in several studies. This is known as “inter-individual heterogeneity. With respect to VO₂max (see image), the HERITAGE study neatly showed this heterogeneity, as did my own work in individuals with obesity. Neither study, however, found that baseline VO₂max was associated with the training-induced change in VO₂max, i.e. people with a low baseline are not necessarily destined to be poorly trainable.

In his book, The Sports Gene, David Epstein presents examples of elite performers who had a high baseline and a high capacity to respond to training. Such examples are golden eggs when it comes to success. One of the most famous is Jim Ryun, an Olympian and former mile world record holder. At the age of 15, he ran his first 1-mile time-trial in 5:38 (high baseline). He started training and within a year he lowered his time to 4:07.8 (high responder). Within another year, while still in high school, he went on to break 4-minutes.

The Jim Ryun story is mind-blowing but in such a study of a single elite performer, an inherent “survivorship bias” exists that is frequent in the scientific study of elites. Firstly, the sample of elite performers is typically very small. But, more importantly, the studies of elite performers typically do not include the millions of people who are not elite, i.e. the ones who didn’t have the high baseline, or did not make it, didn’t want to make it, or never tried. Furthermore, when “selecting” talent, it is a zero-sum game because there is an inclusion bias as well as an exclusion bias. For example, imagine a hypothetical scenario where during a selection race in primary school there is one spot available in Patrick Sang’s training group. Eliud Kipchoge runs fastest and is selected. He now has access to the best facilities, the best people, the best carbon-sprung shoes (ah-hem). Good for him. Alas, just 1-second behind Eliud is his (hypothetical) identical twin brother, Moses, who is just as good (high baseline) and very likely has the same potential to become great (high responder) but who’s potential is never discovered due to spurious selection processes. My point here is that, yes, a genetic component for sporting excellence exists, the HERITAGE study nicely portrays that people completing the same nurture (training) have hugely diverse outcomes because of nature (genetics), but the field of elite genetics has some limitations and we are a country mile (run pun intended) from knowing everything. Additionally, there are other factors involved besides the redundant comparison of nature vs. nurture.

Nature is nurtured. Simple. Right?

The physiological goal of your training for running-based sports, including obstacle racing, is primarily to improve your VO₂max, your velocity at VO₂max, your strength and power, your economy/efficiency, and your economy/efficiency threshold (which you might call your lactate threshold). Each of these has a genetic basis and the extent to which each of these can change also has a genetic basis. Each exercise bout elicits a stimulus to which there are several responses in most of your organ systems. Without regular exercise combined with appropriate recovery, there is no adaptation and improvement. Consequently, training is about applying appropriate, well-timed, and progressive stimuli that manifest your best adaptive potential possible (i.e. your genetic maximum) from the attributes you were born with. For sure, an appropriate training approach (which encompasses all things exercise and recovery) counts for a lot, but the perfect training approach loaded on top of poor genetic potential will never produce an Olympic Champion. My personal mantra on this topic is that “Training smart can beat talent if talent doesn’t train smart”. Nevertheless, there are many external environmental facilitators that must be in place to help nurture talent - good upbringing, good life-long nutrition, good opportunities, self-awareness of recovery, appropriate and “hygienic” sleep, access to facilities/terrain/equipment, having the passion/desire/motivation, and resilience to failure (grit). We can perhaps agree that, to achieve your best, deliberate practice is necessary but not sufficient.

“Jamaica, we have a bobsled team”. The lottery beyond genetics.

The chance of becoming an Olympic Gold medallist is slim. At the Rio 2016 Olympics, approximately 300 gold medals were awarded. For the sake of simplicity, the population of the world in 2016 was roughly 7 billion, hence, there was a 1 in 23 million chance of being a champ! Incidentally, that’s about the same chance as winning a lottery jackpot. Multiple factors contribute to making a champion. Some of these we can control, others we cannot. Furthermore, there is a little bit of good fortune involved. For example, where were you born? This can have an influence. If the stork delivers you to the world in say, Jamaica, then you are very likely to be interested in sprinting and are very unlikely to want to be a cool Bobsleigh runner. Well, OK, there are exceptions but you get what I mean. Daniel Coyle, author of The Talent Code, calls this “the windshield phenomenon” - the people you see every day through your windshield fuel your motivation. In Jamaica, those people are world-beating sprinters. In New Zealand, they are professional rugby players. In America, they are MLB, NBA, and NFL stars. What month of the year were you born in? That can also matter. In ice hockey, there is a selection bias towards Canadians born in January, February, or March (i.e. in the first quarter of the Canadian school year) being drafted into the NHL. As I hope you are beginning to see, the journey of creating a champion is vastly complex — the nature versus nurture debate is a futile argument. Deliberate practice and talent should never be considered separate entities, they are interlinked and one does not negate the other. There is never a situation where solely talent or solely the development of talent contributes to 100% of success in athletic performance at the world-class level. Further, the notion that deliberate practice alone or simply layered on top of talent is all we need for success is absurd. Yes, a world-class performer has a gift and has worked hard, but they were also motivated to work hard and have also had to make good decisions and have been fortunate to be presented with or motivated to seek out opportunities to support quality development and learning. We cannot prove that genetics make a champion but we cannot ignore the evidence suggesting that it helps. It is clear, however, that deliberate practice alone is not sufficient and that motivation, opportunity, and (good) decision making are all essential ingredients for success.

So, what do you do now?

Although eugenics has regrettably been practised in modern history, fortunately, it died out. You cannot pick your parents but you can guide your destiny. My advice is to try a range of things. Discover what you enjoy most. Reveal your passions. Identify your strengths. Then find an enjoyable way to hone your talent. Select a challenging but realistic goal, then instil yourself with confidence that you can achieve it. If you have never run in your life and after setting out for an experimental jog you end up running 5 kilometres in 17-minutes, it is very likely that you have a nice genetic template. However, there were 251 sub 17-minute finishes in Parkruns around the globe this week alone. Also, check out where you would have placed in a half-marathon that took place in Japan a couple of weeks ago. Your natural talent, therefore, would need some considerable nurture for you to become internationally-competitive let alone dominant.

Fortunately, the more complex a task is or, in the context of sport, the more ways there are to win, then the more that nurture (deliberate practice aka training ) may contribute to the likelihood of success. Noting of course that the more complex a task is, the longer it will take to master all of the skills. David Epstein described a beautiful example of this in relation to air traffic controllers, in whom the more complex their task is the greater the level of separation becomes as the more hours of practice are acquired. This makes for a nice segue to obstacle course racing (OCR), a multi-disciplinary sport that requires a high level of cardiorespiratory fitness (long-distance mountain running) combined with a high level of muscular strength and power (climbing, carrying, pulling, pushing), coupled with a high level of skill (rig-swinging, ninja/parkour, spear throwing, etc). Sprinting 100 metres in a straight line has fewer ways to win than a game of tennis or golf. In OCR, there are multiple facets of fitness to develop all of which have a genetic basis but all of which can also be nurtured with time and patience.

And so, back to the beginning. Nature is 100% important until nurture is introduced and subsequently promoted to being 100% important. Nurturing our talent helps us realise our genetic potential. We all have a ceiling that our fitness can reach. No matter whether you are aiming to win an Olympic Gold or trying to run a new PB at your local Parkrun, aim to exploit the genes your parents donated to you all those years ago. You were born with good bits, hone them and use your time on this planet to find your “fitness ceiling” by creating the best environment that will support you in acquiring more good bits. But in doing so, always remember that training is a game of chess - there are multiple journeys to achieve your goal... and you are unlikely to become a grandmaster.

Thanks for letting me into your genes. Until next time, stay nerdy and keep empowering yourself to be the best athlete you can be by training smart...

Talent + Deliberate practice + Opportunity + Motivation + Good choices = Success. Thomas Solomon at Veohtu.

Disclaimer: I occasionally mention brands and products but it is important to know that I am not affiliated with, sponsored by, an ambassador for, or receiving advertisement royalties from any brands. I have conducted biomedical research for which I have received research money from publicly-funded national research councils and medical charities, and also from private companies, including Novo Nordisk Foundation, AstraZeneca, Amylin, A.P. Møller Foundation, and Augustinus Foundation. I’ve also consulted for Boost Treadmills and Gu Energy on their research and innovation grant applications and I’ve provided research and science writing services for Driftline and Examine — some of my articles contain links to information provided by Examine but I do not receive any royalties or bonuses from those links. These companies had no control over the research design, data analysis, or publication outcomes of my work. Any recommendations I make are, and always will be, based on my own views and opinions shaped by the evidence available. My recommendations have never and will never be influenced by affiliations, sponsorships, advertisement royalties, etc. The information I provide is not medical advice. Before making any changes to your habits of daily living based on any information I provide, always ensure it is safe for you to do so and consult your doctor if you are unsure.

If you find value in this free content, please help keep it alive and buy me a beer:

Buy me a beer.

Share this post on your social media:

Want free exercise science education delivered to your inbox? Join the 100s of other athletes, coaches, students, scientists, & clinicians and sign up here:

Exercise physiologist, Dr Thomas Solomon at Veohtu

About the author:
I am Thomas Solomon and I'm passionate about relaying accurate and clear scientific information to the masses to help folks meet their fitness and performance goals. I hold a BSc in Biochemistry and a PhD in Exercise Science and am an ACSM-certified Exercise Physiologist and Personal Trainer, a VDOT-certified Distance running coach, and a Registered Nutritionist. Since 2002, I have conducted biomedical research in exercise and nutrition and have taught and led university courses in exercise physiology, nutrition, biochemistry, and molecular medicine. My work is published in over 80 peer-reviewed medical journal publications and I have delivered more than 50 conference presentations & invited talks at universities and medical societies. I have coached and provided training plans for truck-loads of athletes, have competed at a high level in running, cycling, and obstacle course racing, and continue to run, ride, ski, hike, lift, and climb as much as my ageing body will allow. To stay on top of scientific developments, I consult for scientists, participate in journal clubs, peer-review papers for medical journals, and I invest every Friday in reading what new delights have spawned onto PubMed. In my spare time, I hunt for phenomenal mountain views to capture through the lens, boulder problems to solve, and for new craft beers to drink with the goal of sending my gustatory system into a hullabaloo.

Copyright © Thomas Solomon. All rights reserved.