Genes and Elite Running Performance
Hard Work vs Genetics. Nature vs Nurture. Genotype vs Phenotype.
There comes a point in every runner’s career where the old adage, hard work beats talent when talent doesn’t work hard, no longer rings true. This realization can be a difficult one. After all, isn’t running the epitome of the working man’s sport, in which the harder one works, the more mileage one runs, and the cleaner one lives, the better runner one will be?
Unfortunately, this principle only holds true to a certain extent. On a very basic level, a runner’s prowess is determined long before he laces up his first pair of running shoes or ever steps foot onto a track.
The genotype–phenotype distinction is drawn in genetics. “Genotype” is an organism’s full hereditary information. “Phenotype” is an organism’s actual observed properties, such as morphology, development, or behavior. This distinction is fundamental in the study of inheritance of traits and their evolution. (Wikipedia)
The genetic influence on running performance and other types of exercise is dizzyingly complex. So complex that my best efforts to write on how genes may have an impact on the science of elite performance will definitely fail to capture just how hugely complex the various interactions and connections are. It’s so complex that despite the grueling efforts of scientists to find “the hidden performance genes”, they have failed greatly.
While genes may be too numerous, they are important. Although we do not possess the caliber of technology needed to understand them better, that does not mean we should put them aside.
Genes are key elite performance factors in all sports.
Physiological variables and environmental factors that correlate to elite performance are so complex that we tend to take a very simplistic view that genes are the dominant factor in determining a level of success in running. An extremely facile view is that genes can act as magic bullets to propel runners with the right genetic compositions to “inevitable” success. Scientific American even predicted that most performances at the 2012 Olympic Games would mainly depend on key genes within the nuclei of athletes’ muscle cells.
In addition to this, there is a common belief that an examination of a runner’s genes can determine whether one should become a marathoner, a sprinter, or a middle-distance athlete.
What should we believe?
The most powerful genetic influence of performance.
On the same note, the most powerful genetic influence of performance is biological sex. Some people may react negatively to this statement, but it is just a fact, not a statement of inferiority or superiority. It is the very reason we embrace separate categories for all kinds of competitions in all sports. If we did not recognize that women and men should compete in separate categories in all sports, not just running, how could women be competitive?
Let’s take marathon running as an example. Paula Radcliffe holds the marathon world record for women. We are talking about a performance that is easily the best ever by a woman. Now, she would have ranked 473rd in an “open world list” in 2009. What does this mean? 472 men were way faster than her in a single year. In history, that time is ranked 3,205th.
The gap practically exists in all sports ranging from 100m to 200km – a 10 to 15 percent difference between the best men and women is always seen across the board.
It’s just nature.
Whether the runner will be a sprinter, hurdler, or marathon runner has more to do with genetics and ancestry than the work that goes towards those goals. So, which genes make great runners great? Thanks to a number of advances in recent technology, especially due to the Human Genome Project, scientists have a better understanding about this question than ever before.
Undoubtedly, every fan of track and field has noticed the obvious: runners from African nations are nearly an unbeatable force. An easy explanation is that African runners are typically impoverished and with little opportunity, simply train harder in order to provide a better life for themselves, their families, and their villages. These runners are also adapted to tough training conditions.
They run in the heat and often at high altitudes, such as in Eldoret, Kenya, which is 7,000 – 9,000 ft above sea level. However, if one looks closer at the results, an interesting trend is revealed: West Africans dominate sprinting, while East and North Africans excel at distance running, with little cross over. As a nation unlike the United States or most of Europe, with very little genetic diversity, this result begs the question: how much are genetics linked to athletic performance? The answer is surprising: nearly all of an athlete’s ability comes from predetermined factors such as muscle fiber composition, efficiency, bone structure, and even personality.
A 2003 study published in the American Journal of Human Genetics implicates skeletal-muscle actin-binding protein, α-actin-3 (ACTN3), as a gene necessary for elite sprinting performance1. This gene is found in fast twitch muscle fibers, and is responsible for creating high force at high velocity – such as the force needed to burst from the starting blocks of the 100m dash. At the Olympic level, researchers found there were no sprinters deficient in the ACTN3 gene, while endurance athletes were mostly deficient, as was the control group (healthy, non-athletic males). This “speed gene” appears to be necessary in order to reach elite levels in sprinting.
Among the general population, some 18% of people are completely deficient in the speedy-muscle-contracting protein — they inherited two defective copies of ACTN3.
Just as some athletes are born with the “sprinting gene,” each athlete arrives at the starting line with a predetermined amount of fast twitch vs. slow twitch muscle fibbers3. As the names suggest, fast twitch muscles are able to contract at a quicker rate, which is crucial for sprinting. Slow twitch muscles, on the other hand, are useful for long distance races. Additionally, slow twitch muscles are unable to be converted into fast twitch, meaning that the amount of fast twitch muscles you are born with is the amount you will always have. For elite sprinters, at least 70 – 80% of muscle fibers are fast twitch, with gold medalists typically having fast twitch muscle composition in the 80 – 90% range.
It is not a coincidence that the majority of runners have “Type A” or addictive personalities. Running, a sport where a lot of lonely miles, daily sacrifices, and dogged determination is necessary for success, is well-suited towards the individual who cannot justify giving up and is preternaturally driven to continue. Personality traits, just like physical attributes, are based on the genetics that are passed down from our parents and grandparents. These traits, however, can also be a double edged sword and are common reasons why runners, male and female alike, have a tendency towards unhealthy habits, such as eating disorders, for the sake of success.
In running, a sport where light and lean equals fast, the frame a runner is born with can play a huge role in developing the runner’s ability. Although no one likes to think that something as simple and unchangeable as skeletal and muscular structure3 can lay the foundation for a runner’s success, it does indeed make a difference. For distances totaling 5k or above, researchers have suggested that for every pound of body weight a person loses (within reason), 6 – 8 seconds per mile can be shaved off a personal best time. How does this affect two runners already in the low BMI range? In many instances, runners with the smaller frame tend to perform better.
Carrying less mass per frame, having longer limbs, shorter torsos, and being more slender in general tends to improve running efficiency, which leads to faster times and fewer injuries. Although there have certainly been exceptions to this rule (take, for instance, Paula Radcliffe of Great Britain who holds the women’s marathon record, yet stands 5’8’’), the average height for world class male marathoners is 5’5’’. Elite women rarely stand taller than 5’3’’. It is not secret that small stature is an advantage.
For sprinters, the opposite holds true. Bodies are compact, muscles are big and powerful, and although body fat percentages may be similar to that of distance runners, very few other similarities exist. Muscles such as hamstrings and glutes, commonly underdeveloped in distance runners, are large and powerful in sprinters.
Not All People Can Become Athletes
A 2013 study performed by scientists at Loughborough University2 shows that 20% of people are ill-suited to marathon training and have genes that do not re-model effectively under regular high or low intensity training. Their body’s ability to get oxygen to their muscles is reduced, resulting in a reduction in performance. In other words, one- fifth of people do not respond at all to training. Even if they push themselves as hard as everyone else, their muscles just can’t extract the same amount of oxygen.
Proponents of a highly dominant role for genes in determining running performance started pointing to this study from 2013, which is actually a discovery of about 100 genes that impact our physical capacity. If one has the right “configuration” of that multitude of genes, he might actually have an inborn talent for running that would get him farther or faster than athletes with less optimal genetic makeup.
Some Closing Thoughts
Although runners of all genetic makeup exist, there will always be subtle variances that are considered an advantage. A genetic glass ceiling theoretically exists, and a runner could potentially max out his or her talent and struggle to improve. However, this should not discourage any runners from continuing to work hard, run more miles, and iron out running form inefficiencies in the gym. After all, even the best runners have “off” days, and having good genes does not necessarily equate to good training habits, the best coaching, or even mental toughness.
Concluding that genes are a paramount factor underlying elite running performance is premature. Training is considered to be the most important extrinsic, as it requires a level of discipline that only 0.01% can sustain. Those are the elite runners.
Hard work can easily outperform talent and genetics, but what happens when an inborn athlete puts the effort to become one of the greatest runners of all time? Will genes matter in the equation?
1. Yang, N., MacArthur, D. G., Gulbin, J. P., Hahn, A. G., Beggs, A. H., Easteal, S., & North, K. (2003). ACTN3 Genotype Is Associated with Human Elite Athletic Performance. American Journal of Human Genetics, 73(3), 627–631.
2. Marathon running all in the genes, say Loughborough scientists.
3. Wilson JM, Loenneke JP, Jo E, Wilson GJ, Zourdos MC, Kim JS. (2012). The effects of endurance, strength, and power training on muscle fiber type shifting. J Strength Cond Res. 2012 Jun;26(6):1724-9. doi:10.1519/JSC.0b013e318234eb6f.