Is There More to Sporting Success than Good Genes?
Everybody has come across that one person who is good at any sport they try; they were the star high jumper, runner, basketballer and swimmer. The question is, is this due to having ‘high performance’ genes or are other things at play in order to make that person exceptional at sport in general? Scientists have found over 200 genes that can be linked to physical performance; the most commonly known and studied performance gene is ACTN3 (Epstein 2010). However, many people worldwide have the right combination of ACTN3 and not each and every one of them is a star runner. Therefore, there is evidence that more than just the ‘speed gene’ is required in order to be exceptional. Due to length restrictions, the role of ACTN3 will be discussed and the idea of other factors influencing sporting superiority will only be touched upon.
ACTN3 is known as ‘the speed gene’ (Epstein 2010, Rushin 2011). The ACTN3 gene encodes the protein, [alpha]-actinin-3, which is responsible for the contractions of the glycolytic fibres of the human skeletal muscle (MacArthur & North 2007). This protein is only found in ‘fast-twitch’ fibres which contract rapidly during short outbursts of energy in sports, such as sprinting (MacArthur & North 2007, Epstein 2010). Every person has two copies of the ACTN3 gene; however there are 2 variants of the gene, R and X (MacArthur & North 2007, Epstein 2010). The R variant allows the production of the protein to continue, whilst the X variant stops the protein being produced (MacArthur & North 2007, Epstein 2010). From this, we can conclude that if someone was to have two X variants, they would lack the protein and hence, potentially be worse at sprinting or other sports which require short outbursts of energy compared to someone having at least one R variant.
A biologist from the University of Glasgow, Yannis Pitsiladis, has been collecting samples from many sprinting world record holders internationally and has found that not one has two of the X variants (Epstein 2010). However, he has also studied himself, along with many others and found that, he too, does not hold two X variants; however he is not a runner, per say and definitely not a word record holder and that is the case for many people worldwide(Epstein 2010). This leads to belief that sporting success may not be completely genetics based; this thinking now involves epigenetics, a newer science which is the study of environment and behaviour having the power to turn on or off particular genes (Epstein 2010). Environment and behaviour can include training and also the willingness to train.
It can be concluded that the ACTN3 gene does have an influence on sporting ability. Not only due to its function of encoding the protein that controls the ‘fast twitch’ fibres in human skeletal muscle, but also due to Pitsiladis’ study that none of his successful subjects are host to two X variants. The idea of epigenetics is very interesting, especially in relation to Pitsiladis’ study in which he has included himself and many others worldwide that also do not have two X variants but are in no way close to holding sprinting world records. The evolution of epigenetics will be something to look forward to especially in relation to superior sporting ability. Perhaps one day, biologists will know exactly which genes are required and also the environment and behavioural requirements in order to be a superior athlete.
Epstein, D 2010, ‘Sports Genes’, Sports Illustrated, vol. 112, no. 21, viewed 13 March 2012,
MacArthur, DG & North, KN 2007, ‘ACTN3: A Genetic Influence on Muscle Function and Athletic Performance’, Exercise and Sport Sciences Reviews, vol. 35, no. 1, pp. 30-34.
Rushin, S 2011, ‘Gene Genies’, Sports Illustrated, vol. 115, no. 8, viewed 13 March 2012,