Literature review

by Krysia Collyer on April 13, 2009

The Makings of an Olympian


The dimensions of becoming an Olympic champion are very complex.  It involves countless hours of training and exercising, both in and out of the gym, but also requires being motivated, patient, and passionate.  While all those traits may contribute to the package, what may truly define the greatness of an elite athlete is their genes.  The genetic makeup in an athlete may in part contribute to their athletic success.  This notion was all too apparent at the 2008 Beijing Summer Olympics.  American swimmer, Michael Phelps, dominated airwaves throughout the entire games because of his record breaking eight gold medals.

During the games, media outlets analyzed every possible aspect that could have contributed to the 23-year olds success.  In doing so, it became clear that Phelps’ advantage over his competitors might have more to do with his genetic makeup than his training regiment.  For instance, Phelps was born with hyperflexible joints, allowing his knees, ankles, and wrists to bend about 10 to 15 degrees more than the average person (Parry, 2008, BBC Sports). As a result, he is able to conduct a more powerful flipper kick with both his legs and angles, resembling that of the motion of a dolphin’s tail (Parry, 2008, BBC Sports).

Further, Phelps has an abnormally long torso with short legs.  This in turn allows him to swim faster, as it minimizes his drag and maximizes propulsion (Parry, 2008, BBC Sports). If one were to breakdown every aspect of Phelps’ body, it can be concluded that the composition of Phelps’ body is genetically sound for swimming success.

Another such example can be identified in the 1964 Winter Olympics.  Eero Mantyranta, brought home two gold medals in cross-country skiing for Finland during the games held in Austria.  Although, Mantyranta’s training practices were similar to his fellow competitors, his athletic success came in part as the result of his genes.

Mantyranta was born with a mutation in the erythropoietin (EPO) receptor gene (McCrory, 2003, p.192). This genetic mutation gave him the advantage over the average person, as it “increased the oxygen carrying capacity of his red blood cells by 25% to 50% to the heart,” which in turn allowed him to maintain his endurance during competition (McCrory, 2003, p.192).

With genetics having been identified as contributing to human athletic performance, it’s hard to understand how those athletes without the same genetic predispositions can compete.  In recent years, scientists have been conducting research into this area, trying to find answers to these questions. Subsequently, this research has lead to the development of gene-based technologies, allowing scientists to examine and manipulate an individual’s genes (Haisma, 2004).

As a result of these advances, new worries have arisen, as to how these technologies will impact sport.  One such worry includes the possibility that athletes will look to enhance their own genes in order to get that athletic advantage. In order to do so, competitors can turn to a medical treatment called gene therapy.  According to Dr. H.J. Haisma (2004):

Gene therapy may be defined as the transfer of genetic material to human cells for the treatment, or prevention of disease or disorders. Genetic materials can be DNA, RNA, or genetically altered cells (p.17).

Through the use of gene therapy, athletes are able to use these techniques to enhance their own athletic performance (Haisma, 2004). This in the realm of sports constitutes as gene doping.  Since, the effectiveness of genetic therapies have advanced over the past few years, sports doping agencies such as the World Anti-Doping Agency (WADA) have been scrambling to come up with a test that would catch genetic cheaters.  At this point, there are no concrete tests available to catch gene dopers, and as these genetic-based technologies continue to advance, it may become nearly impossible to distinguish between those who are genetically ‘gifted’ and those who paid for them.

Given the importance of genetics in sport, the discussion in this paper will examine the key findings in genetic analysis of human athletic performance. In addition, as gene-based technologies continue to evolve, new threats have emerged as to how these advances will impact sport.  In this review, genetic medical treatments, gene-doping, and anti-doping tactics will also be addressed.

Literature Review

David J. Smith provides an in-depth review of the many different components contributing to athletic performance.  Smith acknowledges the relationship between genetics and athletics, but maintains that proper training methods, nutrition and rest all play a role in performance (Smith, 2003).  Most notable, Smith provides a compelling argument for the importance of training within sports, whereby he links the number of years put into a sport to athletic success (Smith, 2003).

According to Smith (2003), “a substantial body of evidence suggests that elite performances require around 10 years of practice to acquire the necessary skills and experience to perform at an international level” (p.1107).  Although, Smith identifies the role of genetics in athleticism, noting “genes account for half of performance”, he places emphasis on recovery periods, marking it as a key component to athletic performance (Smith, 2003).

Furthermore, Smith identifies mental or psychological toughness as key components to athletic performance, and thus, should be incorporated into the training regime of the competitor (Smith, 2003).  Taking note of all the psychological traits that influence performance, Smith (2003) identifies the following:

The psychological factors include motivation, aggression, focus, the aptitude to tolerate pain and sustain effort, attitudes towards winning and losing, the ability to cope with anxiety and stress, coach-ability, the competence to manage distractions and the capacity to relax (p.1108).

Therefore, Smith maintains that the manner in which an athlete can cope with the above-mentioned psychological traits may in fact determine their athletic success (Smith, 2003).

In a review of gene-based technologies, Brad McGregor furthers the analysis of genetics within in sport performance.  Within his article, he examines genetic characteristics and their greater impact on training and exercise.  Through his examinations, McGregor identifies several genetic components that influence the body’s reaction to training and exercise.  Some of these components include oxygen intake, heart rate, and an individual’s cardiac structure (McGregor, 2003).  Studies presented as evidence to support McGregor’s argument showed that “30-70 percent of an individual’s cardiac structures and response to cardiopulmonary exercise is genetically pre-determined” (McGregor, 2003, p.9; Patel and Greydanus, 2002).

Moreover, McGregor goes on to characterize structural traits that are not only influenced by genetics but are integral to performance. He notes that athletic institutions are using gene-based technologies to screen youth for genetic predispositions (McGregor, 2003). They are also using the tests to look for characteristics in the body structure that suit particular sports (McGregor, 2003). These characteristics include:

  • Height, length of arms
  • Muscle size, strength and muscle fiber composition
  • Heart size and resting heart rate
  • Lung size and volume
  • Flexibility of joints (McGregor, 2003, p.5; Patel and Greydanus, 2002)

With the above-mentioned characteristics in mind, McGregor provides strong evidence to what percentage of genetics influence an individual structural trait.  McGregor quotes Patel and Greydanus’ 2002 study to back up his argument, highlighting that “genes are responsible for 30% of baseline heart rate and 27% of heart rate variance in response to training” (McGregor, 2003, p.5; Patel and Greydanus, 2002, p.251).

There are over 200 different genes that could influence “athletic performance and health-related fitness phenotypes” (Brey et al, 2009, p.34).  One such gene is alpha-actinin 3 (ACTN3).  Nan Yang et al. (2003) argue:

[T]here are highly significant associations between ACTN3 genotype and athletic performance.  The presence of ACTN3 has a beneficial effect onthe function of skeletal muscle in generating forceful contractions at high velocity, and provide an evolutionary advantage because of increased sprint performance (p.627).

These researches provide interesting accounts of the ACTN3 gene, as their findings suggest that in both male and female sprinters exhibited “higher frequencies of the 577R allele” (Yang et al., 2003, p.627).  Study found that R577X, which is expressed in muscle, tapped in at much higher numbers than expect in female sprint athletes, and lower in endurance athletes (Yang et al., 2003). Subsequently, researchers did find dissimilar results between the sexes, which they concluded that the ACTN3 gene affects men differently than women (Yang et al., 2003).

In 2004 report by the Netherlands Centre for Doping Affairs, Professor Dr. H. J. Haisma explores the evolution of doping in sport.  In his examination, Haisma identifies gene doping as the next possible threat to sport, suggesting that the advances in gene-based technologies and genetic therapy will likely persuade unscrupulous athletes  (Haisma, 2004). Since “gene therapy may be defined as the transfer of genetic material to human cells for the treatment, or prevention of a disease or disorder,” such transfer of genetic material may become desirable for athletes in the future, as the ability to transfer  (Haisma, 2004).

The report identifies erythropoietin (EPO) gene as the potential first gene doped in sport (Haisma, 2004).  Haisma argues that EPO gene receptor “speeds up wound healing, and ameliorates muscular soreness after exercise,” which in turn may be a desirable feature for athletes experiencing soreness after exercise or suffering from an injury (Haisma, 2004, p.13).  EPO is a commonly used treatment for people who are suffering from anemia or provided to cancer patients to offset the harsh side effects experienced during chemotherapy (Haism, 2004).

Tom D. Brutsaert and Esteban J. Parra examine the complexities of human athletic performance through an analysis of the interaction between genes (G) and environment (E) (Brutsaert and Parra, 2006).  Within their review, these researchers provide evidence to support a correlation between genetics and human athletic perform, but their findings suggest that environment influences affect the outcome of those athletic abilities (Brutsaert and Parra, 2006).

Brutsaert and Parra (2006) maintain that “gene-environment interaction (G x E) as a means of understanding variation in human physiological performance” must be further studied in order to understand the many dimensions of becoming an elite athlete (p.109).  Such notion is further emphasized in their categorization of environmental and human physical performance research.  Within this subsection, Brutsaert and Parra (2006) argue:

[E]lite athletes are those who respond in extraordinary ways to training in order to unlock an already present potential, and G-by-training interaction may itself be affected by G x E taking place over the lifetime
of an individual.  Thus, a broader consideration of environmental effects should be emphasized (p.115).

Although, further study is needed in the area of environmental impacts on human athletic performance, Brutsaert and Parra identify “unmeasured environmental effects” as a major problem in advancing this research (Brutsaert and Parra, 2006, p.117).  Since there may be a correlation between genetics and environment within athletics, Brutsaert and Parra (2006) maintain, “understanding the origins of variation in human athletic performance will require an integration of both, genetic and environmental, researchers and research approaches” (p.117).

George Gayagay et al. study “the genetic markers that may contribute to making an elite athlete” (Gayagay et al., 1998, p.48).  In this study, Gayagay et al. examine the angiotensin-converting enzyme (ACE) in 64 Australian national rowers and compared the sample against a normal population (Gayagay et al., 1998).  The results revealed that the rowers had an excess of “ACE I allele and the ACE II genotype” (Gayagay et al., 1998, p.48).  According to Gayagay et al. (1998):

[T]he study demonstrated a significant association between a measurable genetic polymorphism and elite athletic performance. An excess of the ACE I allele – might represent, in part, a “healthy” cardiovascular system (p.50).

Therefore, this study provides evidence to suggest an association between the presence of the ACE gene and improved athletic performance in endurance sports, as ACE is linked with a strong cardiovascular system (Gayagay et al., 1998).

Dr. Oliver Rabin, the World Anti-Doping Agency (WADA) Science Director, identifies the challenges of catching gene dopers.  He states (2006), “gene or cell doping, referring to the abuse of gene or cell therapy to enhance performance in sport, is considered to be one of the most difficult challenges facing the anti-doping scientific community” (p.1).  Dr. Rabin attests that WADA has placed gene doping at the top of their research priority list, and in doing so, has accepted and funded 11 projects dedicated catching cheats (Rabin, 2006).  Dr. Rabin (2006) goes on to note that this type of doping may pose a challenge to creating a reliable test, as “it is still unknown which maker will offer a sufficient specificity, sensitivity ad window of detection to transfer into valid and practical anti-doping methods” (p.1).


In light of the recent genetic discoveries within human athletic performance, the literature reviewed provided sound arguments for the influential role genetics plays in sports.  As technology is evolving, more than ever is it important to understand how geneticists determine what athletic components individuals are predisposed to in sports. Since human athletic performance is linked to particular genotypes within human DNA, scientists can pinpoint whether an individual will excel in either endurance performance or muscle-strength sports (Rankinen, 2006). This in turn may change the nature of sports competition in the future, as athletes may decide to venture into a particular sport based upon their genetic predisposition, as opposed to their love for the game.


Bray, M.S., Hagberg, J.M., Perusse, L., Rankinen, T., Roth, S.M., Wolfarth, B., &  Bouchard, C. (2009, January). The human gene map for performance and health-related fitness phenotypes: The 2006-2007 update. Medicine & Science in Sports & Exercise, 41(1), 34-73.

Brutsaert, T.D. and Parra, E.J. (2006).  What Makes a Champion?  Explaining Variation in Human Athletic Performance.  Respiratory Physiology & Neurobiology, 151. 109-123.

Gayagay, G., B. Yu, B. Hambly, T. Boston, A. Hahn, D.S. Celermajer, and R.J. Trent. (1998).  Elite Endurance Athletes and the ACE I Allele-the Role of Genes in Athletic Performance.  Hum Genet, 103. 48-50.

Haisma, Dr. H.J. (2004). Gene Doping. Netherlands Centre for Doping Affairs. 1-35.

McCrory, P. (2003). Super Athletes or Gene Cheats? British Journal of Sports Medicine, 37. 192-193.

McGregor, B.  (2003).  The Use of Gene-Based Technologies for Talent Identification in High-Performance Sport. Bond University: Master of Sport Science.  Retrieved December 10, 2008

Parry, S. (2008, August 13).  What Makes Phelps So Special? BBC Sports.  Retrieved
December 21, 2008

Patel, D.R. and Graydanus, D.E. (2002).  Genes and Athletes. Adolescent Medicine. 13(2). pp. 249-255.

Rabin, O. (2006).  WADA Program and Perspectives on Gene Doping Detection.  World Anti-Doping Agency (PDF).  Retrieved February 6, 2009http://www.wada-

Rankinen, T., M. S. Bray, J. M. Hagberg, L. Perusse, S. M. Roth, B. Wolfarth, and C. Bouchard. (2006).  The Human Gene Map for Performance and Health-Related Fitness Pheotypes: The 2005 Update. The American College of Sports Medicine. 1863-1888.

Smith, D. J. (2003).  Framework for Understanding the Training Process Leading to Elite Performance.  Sports Med, 33(15). 1103- 1126.

Yang, N., D. G. MacArthur, J.P. Gulbin, A. G. Hahn, A. H. Beggs, S. Easteal, and K. North. (2003). ACTN3 Genotype is Associated with Human Elite Athletic Performance. The American Journal of Human Genetics ,73(3). 627-631.

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