Blog| ByDominique Stasulli

The topic of nature versus nurture presents itself in the world of elite sporting events as a sustained debate. Are world-class athletes born or bred? Is there a certain amount of practice that can turn the average athlete into an elite? There are two main theories that aim to explain both arguments in the spectrum of the debate: the genetic influence model and the deliberate practice model.

The genetic model argues that a predetermined set of genetic traits predicts athletic potential and success. These physical traits are polygenic, or coded by many genes, producing the ultimate elite phenotype (Tucker & Collins, 2012). The four most influential traits include: gender, height, skeletal muscle composition, and VO2max. The most obvious influence on athletic performance is the drastic segregation of male and female performances; this is proof of genetic predisposition to athletic potential. Height is developed by both nature and nurture (nutrition), and is very predictive of sport-specific success—or example, the height required for basketball players is not conducive to long-distance running.

Studies have found a number of VO2max genes in untrained individuals, which are inherently genetic, and also genes activated by training, which are environmentally influenced (Tucker & Collins, 2012). VO2max is a strong predictor of maximal aerobic capacity and, thus, performance in endurance-based events. Being genetically gifted with a superior aerobic capacity automatically places the athlete in an advantageous position for accelerated graduation to the elite level. Skeletal muscle properties are subject to similar genetic and environmental influences. Hence, an athlete born with greater strength capacity in their musculature will have an easier time transitioning into strength-based sports, such as football or wrestling.

The dominance of East African runners in the middle- and long-distance events is well-known, especially in the last decade where 85% of the Top 20 ranks in the world have come from this region (Vancini et al., 2014). These runners are primarily of Kenyan and Ethiopian descent and classically possess high VO2 max, hemoglobin, hematocrit, tolerance to altitude, bland diets of rice and beans, optimal running economy, and optimal muscle fiber type composition (Wilber & Pitsiladis, 2012). Much research has explored the possibility that genetic factors have yielded an advantage in this particular population, especially genes responsible for anthropometric, cardiovascular, and muscular adaptations to training (Vancini et al., 2014).

The first studies performed on this group focused on mitochondrial DNA (mtDNA) variation, which is an easy way to phylogenize specific haplotypes, or sets of inheritance patterns, as they were passed through the maternal genetic line. If a haplotype is localized to one area of origin or one people group, it may be considered a strong indicator of a particular phenotype. It turned out that the gene pools between Kenyan and Ethiopian runners varied so greatly that the support for mtDNA’s role in athletic giftedness was inconclusive (Wilber & Pitsiladis, 2012).

Two genes, in particular, have been more recently theorized to produce high performance phenotypes. The first is angiotensin converting enzyme (ACE); an insertion polymorphism on this gene results in a genetic downregulation of ACE, resulting in greater cardiorespiratory fitness and tolerance to altitude/oxygen-deprivation (Vancini et al., 2014). Interestingly, a deletion of the same gene results in ACE upregulation and, thus, increases musculoskeletal fitness ideal for power competitions. The second gene is alpha-actin-3 (ACTN3), which can polymorph into the R577X variant; the XX allele on this gene is found with higher frequency in endurance athletes and does not result in the expression of ACTN3.

None of the current evidence supports a conclusive explanation for either of these genes being solely responsible for East African success. While it is unlikely that a single nucleotide polymorphism (SNP), such as the ones mentioned above, is the determinant of athletic giftedness, there is much promise for the rapidly expanding field of genomics to produce answers in the near future.

There are also environmental factors that may play a role in the success of middle- and long-distance East African runners. Physiological adaptations, diet and nutrition, and socioeconomic factors are all worth equal consideration in the development of these superior athletes. Certain physiological parameters have measured higher in this population, such as total hemoglobin, VO2 max, and hematocrit; this is attributed to the altitude at which these Africans live and train, which falls in the range of 2,000-2,500 meters (6,500-8,200 feet) (Wilber & Pitsiladis, 2012).

Exceptional cardiovascular development may be a result of 86% of Kenyan and 68% of Ethiopian international elites using running as a primary means of transportation to school as children (Wilber & Pitsiladis, 2012). VO2 max, a measure of maximal oxygen uptake, did not appear significantly dissimilar than other elite athletes of different nationalities despite their gap in performance, indicating that there is more than VO2 max that plays into the Africans’ success. Similar results were found with the hematological values (Wilber & Pitsiladis, 2012).

The traditional East African diet is low in fat and composed of roughly three-quarters carbohydrates, derived mostly from vegetables, fruits, and high-glycemic index grains such as ugali, a potato-based cultural food (Wilber & Pitsiladis, 2012). Even the staple drink is chai, a milky tea made with significant amounts of sugar, which serves as the main source of glycogen replenishment in athletes post-workout. Socioeconomic conditions provide a substantial amount of motivation to achieve a better quality of life as an individual and also for that individual’s immediate family. About half of Kenya’s population and 40% of Ethiopia’s is under the World Health Organization (WHO) poverty line, calling for a desperate need to utilize the gifted resources present throughout the generations of talented athletes.

While physiological parameters are impressive in East African distance runners, they are not significantly superior to their elite counterparts of differing nationalities. To explain this population’s outlying performance times, we need more pieces to the puzzle that simply haven’t been uncovered by the research yet. It may just be a prime combination of genetic and environmental factors that mold into supreme athleticism and phenomenal endurance capacities.

The deliberate practice model suggests engaging in sport-specific practices during critical points of motor skill development (Tucker & Collins, 2012). Deliberate practice is defined as activities that possess complete focus on developing a particular aspect of sporting performance, which may activate the athletic potential genes present in every healthy individual’s DNA. This model proposes that 10,000 hours of training over the course of a 10-year period will allow an athlete to breach elite level status. According to the theory, any athlete who fails to meet this level of competition status must have violated the 10,000-hour/10-year rule in one capacity or another. There are many loopholes to this deliberate practice model. For one, it does not explain how some athletes reach the elite/international level of competition in less than 10 years of participation in the sport or with less than 10,000 hours of practice. Secondly, it does not explain why some athletes may meet or exceed those requirements in training and still fail to breach the expert level in sport. These outliers prove the need for additional research in this debate. There must be some other factors at play, whether they be genetic, mental, or emotional drivers that either accelerate or hinder the athletic development process.

The nature versus nurture debate can stretch to argue natural giftedness over learned ability in determining athletic talent potential. Do natural talent and acquired talent both allow for the same potential to be achieved in the end? Tranckle and Cushion (2006) describe the work of Gagné on the subject of innate and acquired talent. Gagné describes a continuum in which aptitudes/gifts lie at one end and competencies/talent lie at the other. Gifts are genetically inborn, but may take maturation or informal learning for them to become fully expressed; talent, on the contrary, is developed methodically over time, and heavily influenced by external sources of motivation and opportunity. Most often giftedness and talent are thought of as equal and interchangeable terms, though distinguishing between the two is important.

Gagné created four categories of natural abilities: intellectual, creative, socio-affective, and sensorimotor (Tranckle & Cushion, 2006). Under these subcategories, there are the following attributes, though not all-inclusive: reasoning, metacognition, innovation, retrieval fluency, originality, perceptiveness, empathy, leadership, and various components of the sensorimotor system. Intrapersonal catalysts such as personality, motivation, temperament, and well-being factor into the developmental process; environmental catalysts also affect the athlete’s development through physical, cultural, social and familial influences, in addition to program participation and coaching interventions.

This continuum is not to say that an athlete must fall at either end of the spectrum, exclusively. Rather, some athletes may start with natural giftedness, mature those gifts, and progress along the continuum to develop skills environmentally, with the end-product being the lump-sum of talent. Other athletes may not be born with innate gifts, but rather begin further up on the athleticism continuum, with only the option of skill mastery to maximize end-talent potential. Talent identification has sparked much debate in the research field and it seems there is no conclusive methodology for recognizing and delineating talent from giftedness in athletes. As outlined above, the distinction is important in order for a coach to know how to approach the developmental process, through informal or formal teaching processes.

It remains uncertain whether giftedness, skill acquisition, or a combination of the two is the optimal route for maximizing talent potential.

The question of potential remains unanswered. By Gagné’s continuum, it would seem as though giftedness allows for a premature advantage in the developmental process, as if starting with a lead. However, there is quite a bit of chance to play into the athlete’s development, with limited areas of black and white. It remains uncertain whether giftedness, skill acquisition, or a combination of the two is the optimal route for maximizing talent potential.

With the athletes that I coach, I reinforce hard work ethics and positive mindsets over any and all natural God-given talent. A coach can embrace the gifted athletes and push them to the top with relative ease, but I find it rewarding to work with the athlete who puts every ounce of effort into the goal, without the reliance on natural giftedness. The latter athlete owns each and every success and failure, whereas the former may easily attribute failure to a lack of maximal work ethic.

The future research surrounding epigenetics holds much promise for the field of exercise science. If coaches can embrace the environmental tweaks necessary for tapping that elite athletic potential in our athletes, then the genetic predilections can not only be maximized, but also expanded upon to build the best performer possible.

Since you’re here……we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF