Have you heard of epigenetics? Why not?
If I were to point out the significance of genetics in athletic performance, it would come as no surprise that genetics provide a strong correlation between athletic performance. But did you know our brain and environment can influence genetic expression and athletic performance as well? Read on if you want to know more about epigenetics...
In scientific terms, we're going to delve into why your brain and environment are paramount to athletic performance.
In athletic performance there are a multitude of factors that relate to an absolute outcome, for example, a 100m sprinter will require significant levels of strength and stamina in order to be competitive at an elite level. High levels of strength and stamina are achievable through dedicated training and yet in certain sports to compete at Olympic level a certain genetic propensity will determine whether an athlete can compete against the best in the world. This is not a racial bias, as statistics and Olympic results repeatedly show that certain racial demographics perform better in specific sports than others, for example, some African and Caribbean nations perform better in long & short distance running events.
And even then, to get to, and remain at the elite stages of performance, significant levels of mental toughness are also required. Mental toughness is the ability to consistently perform toward the upper range of your talent and skill regardless of competitive circumstances. This further clarifies the requirement of both nature and nurture. Athletes who are found to be lacking in certain physical aspects are still able to excel through dedication and application of technique, both mental aspects of sports namely; mental toughness and adaptability.
There are four key components to mental toughness, emotional flexibility, emotional responsivenesss, emotional strength, and emotional resiliency. In regards to nature vs nurture, we can use both sides of this argument to influence elite athletes perform to higher standards, or alternatively, keep them at a higher standard for longer. In order to address both sides of this argument, genetics and psychological resilience will be discussed, the nature and nurture aspects. It is significant to mention that both aspects of elite performance are a highly complex intermingled process. Many physical aspects and learned behaviour in athletes can be achieved by years of development. For example, an athlete who is physically less developed as his peers during teenage years often has to develop methods and technical ability to outclass his more physical opponents.
In a review of athletic performance I'd like to bring to your attention the Finnish cross-country skier, Eero Mäntyranta. It was found that he had a rare disease known as primary familial and congenital polycythemia, a rare genetic mutation which leads to increased red blood cell mass and hemoglobin. His condition resulted in an increase of up to 50% more oxygen carriage in his red blood cells, a major advantage in endurance events. Effectively he had a genetic mutation (X-Men come to mind, anyone?) which allowed him to perform better. In the past, some elite endurance athletes have been known to use blood doping to gain an illegal advantage in competition, whereas Mäntyranta naturally possessed this ability through a rare genetic mutation. His success could simply be accredited to his naturally occurring genetic mutation as an advantage. But it seems, in his case that nature and nurture were both present in shaping him as a successful athlete. As a child he grew up poor and he was forced to ski an hour each way to school every day. In numours interviews Mäntyranta stated that, in his early years he often fantasised about making his way out of poverty through skiing.
So in saying that, where there is anecdotal evidence for mental strength in creating elite athletes. Mäntyranta also had a genetic mutation which gave him a physical edge over his oppononts. But there is another side to genetic predisposition.
Enter Italian Sprinter Pietro Mennea, he held the 200m sprint record for 17 years. A significant achievement for an athlete who was discouraged from sprinting in his developmental years due to his physical build. Almost all of his coaches doubted he would achieve much as a sprinter due to his size and frame, Mennea stated that he always used their discouragement as a stimulus to prove them wrong. It seems then, that both sides of the nature vs nurture argument are equally influential in elite athletes, and even when the physical aspect is less pronounced it seems that the mental aspect is still capable of producing champions at an elite level.
However, there seem to be a few caveats to this theory. Besides the obvious genetic traits which have significant impact on athletic performance such as sex, height, musculoskeletal composition and VO2 max, an indexation system which quantifies physical performance through lung efficiency.
Scientists have also proposed that a genetic predisposition causing advantage over others had very little to do with elite achievement and that exceptional performers are the result of adaptations to extended and intense practice which in turn activate genes that are already contained within our DNA. Further to this there is a developed concept, called the deliberate practice framework, which associated expert performers with 10 000 hours of practice in order to become elite. In a politically correct setting this seems to be a pinnacle of light where all are created equally, unfortunately nature and biology are far from equal.
What this framework does not account for is a complex interplay between genetics, epigenetics and environment. As previously stated, certain sporting disciplines such as long distance running or weight lifting require a genetic predisposition on top of an environmental requirement to achieve greatness. Other scientists disputed this claim in a review titled “You can’t teach speed: sprinters falsify the deliberate practice model of expertise”. According to the Deliberate Practice Model, elite sprinters would only achieve this status through extended and intense practice. However a further scientific study on elite sprinters claims that many, in general, were already exceptional during development in comparison to their peers, it was through dedicated training they became faster. In general, this also occurs much faster than the 10 000 hour framework of practice. Most sprinters do normally not begin dedicated sprint training unless they are already recognized as being faster than their peers.
Both of these claims then seem quite interesting when comparing the Olympic sprinter Mennea. Although both Ericsson et al. and Lombardo & Deaner propose interesting arguments, it seems that nearly each sport or activity has its niche of genetic disposition and environmental interplay. Other than sprinting, weightlifting also has a certain genetic niche when it comes to elite athleticism. There is evidence that a certain genetic polymorphism is associated with muscle power in a study conducted on Japanese strength athletes. The study revealed that a genetic polymorphism known as ACTN3 R577X attributed to a significant difference in maximal power output for men, however not for women.
Further to this, a Korean study linked the ACTN3 R577X polymorphism in discriminating speed performance athletes from strength athletes. Which is contradictory to the Japanese study, both studies examined the same polymorphism yet claim different outcomes in relation to maximal power output for weightlifting, and as for Korean speed athletes the ACTN3 R577X is the main speed gene. There are many other studies discussing the importance of the ACTN3 R577X polymorphism, and its potential influence in discriminating athletes from elite level and not. These studies accordingly attempt to attribute the gene to a direct causal influence on a specific athletic characteristic but considering the varying outcomes between multiple studies it seems further research is required to pin point the importance of this gene. However its general importance in athletic performance is not debated.
When discussing genetics and environment there is also a case to be made for the implications of epigenetics on creating elite athletes. At a basic level our Deoxyribonucleic acid, or DNA, is a molecule that contains genetic information for each individuals’ makeup, of which each individual has a unique code. Our DNA determines who we are as individuals, right down to how we function as individuals, our health, our predispositions and our potential weaknesses to disease or illness.
In a scientific review of current genetic factors in elite athletes there has been a suggestion that up to 66% of genetics associated with elite athleticism are non-modifiable, meaning they were born with a genetic predisposition to athleticism, instead of being able to influence these genetics through their environment. This review also established that genetic variations are highly complex and gene-gene interactions, rare genes or polymorphisms can influence athletic performance. A polymorphism is an inter-individual, functionally silent difference in a DNA sequence that sets each human genome apart.
However, there’s more to genetics than a set sequential code that determines a physical outcome. Recently, research has shown that the environment can influence the expression of genetics in various ways. Epigenetics is an experimental science that studies how the environment can be influential in the expression of genetics. Research has shown that epigenetic influences are important aspects in fine-tuning and coordinating gene expression in adult neurogenesis.
Neurogenesis is a process by which neurons are created from the neural stem cells and progenitor cells to populate the human brain with neurons. This process slows down after birth although it still occurs in some parts of the brain, the hippocampus and the sub-ventricular region. Research has found neurogenesis to be strictly managed by various physical, pathological and pharmacological stimuli and epigenetic processes play important roles in controlling and adjusting gene expression during adult neurogenesis.
In simpler terms, this means that during and after early development epigenetic processes' can determine and shape the biologic makeup of individuals. In the nature vs. nurture debate it seems that both have the ability to influence each other. Studies of adult twins have revealed that significant life events are moderately heritable. Peer group predisposition, social perspectives, drug use, divorce and risk-taking behaviour, amongst others, are moderately genetically heritable but still need an environmental catalyst for these to happen.
In the case of athleticism, diet and exercise are extremely important in epigenetic expression during development. Socioeconomic status can be determinant in the examples listed previously, peer group inclination and social attitudes are part of an athletes’ environment during development and in many cases athletes have used their athletic ability in order to move from poverty to wealth.
Monozygotic twins, MZ twins, also known as identical twins receive the same genetic blueprint from their parents and even though twins’ genetics are very similar, hence the similar appearance. Attitudes and characters of identical twins is often quite different. This is where the influence of the environment can be seen. One of the best examples which explains epigenitics, is the age at which we reach puberty, the environment directly influences our epigenetics. It is through environmental triggers such as diet and stress that children can reach puberty sooner or later. Considering diet and stress levels in children can be highly influential in the successful development of athletes it is not unrealistic to identify diet and stress in developing athletes as significantly important.
Studies have found the heritability of behaviour have an approximate correlation of .3 to .5 in genetic factors and the correlation between behaviour and environment is slightly higher at .5 to .7.
If genetic predispositions are often triggered by environmental ques it seems certain outcomes are quite plausible. In a study using rodents, evidence suggests that during development and in adults, environmental ques can activate intracellular networks that alter the epigenome. In other words, it changes gene expression and neural activity. In a gene-environment (nature vs. nurture) interplay these signals govern individual differences in behaviour, cognition and physiology.
Even though genetic heritability is a spurious relationship, previous examples do not show a direct causal influence. However, it is with greater certainty we can make assumptions about the importance of an athletes' environment. In the past there have been studies conducted that were focused solely on direct causal influences, for example how the ACTN3 R577X polymorphism is accredited strictly to one aspect of athleticism.
Since there are a multitude of factors involved in athleticism it seems a large scale, all-encompassing review is in order to determine what exactly constitutes athleticism.
Many theories hold significance with a large amount of conclusive research behind them, yet it is short-sighted not to include the full spectrum of influences of athleticism at a correlational level. For example, B.F. Skinner, an American psychologist, considered by many as a pioneer of modern behaviourism developed many influential studies on human behaviour. He described children as a tabula rasa or a blank slate, meaning he could develop any child into any profession or skill given the correct shaping.
Although most individuals can learn, and unlearn behaviour through conditioning, it seems individuals with a genetic predisposition towards certain innate skill or behaviour could pick up some behaviour quicker through a genetic propensity and achieve greater levels of mastery than others.
In conclusion, there is a possible practical application for genetic research in order to influence elite athletes. And even though there are companies already offering genetic testing and programs it seems there is, at this time, not enough substantial evidence to warrant such strong claims.
Considerable research has been focused on the ACTN3 R577X polymorphism and it has been successfully linked to athletic performance. But, due to the complexity of (epi)genetics and the environmental influences of athletic performance there is currently not enough conclusive literature to support the practical application of these findings.
There is definitely a foundation for the practical application of genetic research in athleticism however it is yet to be conclusively supported. Considering the importance of genetic dispositions and environmental influences, the next step is to put these in to practice for athletes. There are methods available that cater to genetic vulnerabilities in athletes, as there are mental resilience strategies and mechanisms' available.
And most importantly, at no point should genetic or psychological information precede the importance of sound practice in the guidance of developing athletes in their pursuit to greatness. Also, since the prediction of athletic success is a highly complex process, no methods are mutually exclusive. Nor should they be used for prediction of talent in youth athletes. Not only because this can be damaging to the development of youth athletes but also because every sport has its niche of unique physical requirements and these vary significantly between sports codes.
Simply because a certain polymorphism has been linked to possible increases in athletic performance does not mean they are decisive in creating elite athletes and it currently seems that psychological resilience created by athletes during development is still more important than any genetic predisposition.
Which is a very long-winded, scientific way of saying that mental toughness is still more important than genetics, supplements or whatever the flavour of the month fad is.
By Ted Hanlon.
*For the sake of readability scientific references have been snipped, however they are available if you're legitimately interested.
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