Empowering Human Performance | Athletigen Blog

There's No Perfect Recipe For Success: The Interplay Between Genetics and Environment

Posted by Sean Sinden on Tue, Nov 17, 2015

Athletic performance is an intricate mix between coaching, training, access to resources, motivation, and genetics. There is no one perfect recipe for success, because of the complex dependency between these factors.

Stefan Holm is a Swedish high-jumper who began training in his backyard at just 6 years old. Holm’s intense work ethic and training schedule led him to capture an Olympic gold medal in Athens (2004) as well as a number of European and World Championships. His specialized and repetitious training program resulted in an Achilles tendon roughly four times stiffer than average. This training adaptation allowed him to propel himself over the bar, achieving the highest recorded jump above his own height ever recorded (1’11”), known as height differential.

On the opposite end of the spectrum is the Bahamian native Donald Thomas. Following a friendly wager to prove his jumping prowess to a friend, Thomas was noticed by his local University coaching staff. Eight months later, after some modifications to his approach and a new pair of shoes, he beat out an elite field of competitors, including Holm, and captured the 2007 World Championships.Subsequent inspection would reveal that Thomas not only had long legs relative to his height but that his Achilles tendon was also uncharacteristically long. Thomas rocketed to the top of the professional circuit but has not improved since that day.  

The Achilles tendon is vital to jumping performance due to its ability to store and release elastic energy, like a spring. This spring-like action is known as the stretch shortening cycle and is improved by an increase in length or stiffness of the tendon (1). Tendon length cannot be increased by training and is determined by one’s anatomy whereas tendon stiffness can be improved by training. Tendon stiffness is also likely influenced by the genes that impact the production of collagen proteins (2).

Although jumping ability is not determined by the length and stiffness of the Achilles tendon, it undoubtedly contributes to overall performance. These two differing routes to the pinnacle of a sport highlight the complex interaction of attributes that can result in elite performance. Donald Thomas represents the natural gifts that can help an athlete excel in a given sport, similar to Eero Mäntyranta, discussed in an earlier blog. Stefan Holm, on the other hand, is an example of what can result from two decades of meticulous and calculated practice. This is obviously an oversimplification of the routes to success. Other components, both genetic and experiential, affect an athlete’s potential for success. Holm and Thomas clearly demonstrate the interplay between training opportunities and genetic gifts in those striving to achieve success in their respective discipline.



(1) Belli, A., & Bosco, C. (1992). Influence of Stretch-Shortening Cycle on Mechanical-Behavior of Triceps Surae During Hopping. Acta Physiologica Scandinavica, 144(4), 401–408.
Kjaer, M., Langberg, H., Miller, B. F., Boushel, R., Crameri, R., Koskinen, S., et al. (2005). Metabolic activity and collagen turnover in human tendon in response to physical activity. Journal of Musculoskeletal & Neuronal Interactions, 5(1), 41–52.

Topics: athletics, donald thomas, genetics, Editorial, environment, high jump, stefan holm, track and field

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