The Genetics of Speed
By Abdel Mohamed
Athletes over the years have managed to break records and demonstrate that their hard work pays off on the field. Athleticism and drive is said to be what separates the average person from athletes that exceed typical physical constraints. Although a strong work ethic is a significant reason for their success, geneticists have determined that genes are also a contributing factor to their athletic performance. The ability for someone to be trained is somewhat dependent on genetics: the physical endurance of the body or the type of response the it gives when when being overworked and injured.
An important trait for an athlete to have is speed, which is somewhat heritable. Kenyan and Ethiopian athletes are known as winners of the athletic gene pool as they dominate olympics/sports globally. In fact, the Kalenjin, the Kenyan tribe of sprinters, is a minority in kenya and yet the hold global records in running. What separates them from the rest of the world is their expression of a gene located on chromosome 11, ACTN3, which has been linked with muscle fibers and high velocity muscle contraction. It has been called the "gene for speed" because its expression leads to the production of alpha-actin binding protein, which is related to the absorption of impacts on muscle fibers and glucose metabolism of athletes during training. Its expression is highly more prevalent in athletes and research done on Australia's team of female olympic sprinters in 2012 found that there is no athlete deficient in ACTN3. Even though the gene has been evolutionary conserved, a significant proportion of healthy individuals (18% of Caucasians of European ancestry) are totally deficient in this protein as they are homozygous for a premature stop codon polymorphism in the ACTN3 gene. This means that those with the ACTN3 gene are more genetically apt to perform high velocity or power related athleticism like track and sprint.
Although genetics is not the main reason for why certain athletes are dominant in endurance related sprints, it contributes to their aptitude to be trained and become the fastest group of runners in the world. However, the next time yous see you athletes break records and run at unimaginable speeds, remember that the ACTN3 gene is most likely at work. With the inheritance of the “speed gene,” a new star may be born that will dominate the running world.