Performance markers within human populations

What is the question?

Although a very sensitive topic, science has observed that specific populations seem to perform better in sports than others. It also holds true for certain diseases, such as sickle cell anaemia and even most recently, susceptibility to diabetes. Kenyan and Ethiopian runners dominate the world of endurance running, whereas Jamaican and African-American runners dominate the short sprinting events. Others again, dominate gymnastics, ball sports, to name but a few. However, there are various internal and external factors that contribute to their success.

There has been lots of speculation surrounding the performance advantage, being it genetics or environmental, but thus far, no genetic marker(s) (i.e. intrinsic) can explain these advantages in sporting success. For more on this topic, please click here where Ross Tucker delves deeper into this topic.

Nevertheless, the human body can very easily and relatively quickly adapt to various forms of exercise, such as altered training loads and the environment (hot vs. cold, altitude, etc.). Thus, just because one group excels in a specific sport, does not necessarily mean that their success is genetic. Exposure to the sport, training volume and intensity, and motivation are factors that can significantly influence performance. However, to what extent these factors can push the human body to its limits and bring about the physiological adaptations, are still unclear and must be investigated.

What was found?

There are only a handful of studies that investigated the physiology between athletes, in particular endurance runners.

The overall consensus thus far is that African runners exhibit lower blood lactate at the same running intensity than their European counterparts. Secondly, it appears that African runners have a larger proportion of type IIA muscle fibres. Combined, these two factors should theoretically result in greater force output and a longer time to fatigue. However, we are still a long way as it must still be proven that the cause of the greater performance is indeed as a result of these two factors.

Together with some of the MyoLab’s collaborators, we are busy producing a review article that will focus on black and white sprinters and long distance runners. Many papers have focussed on the genetics, but this review will focus particular on observations and discoveries made on muscle physiology and the overall physiological response to exercise in a laboratory setting. Future studies will then be designed to answer the pressing questions that are still unclear.