Talk about genetic difference between athletes is pervasive in sports. Some differences are easy for all to see and understand, like height for a basketball player or lack of height for a gymnast. Some genetic differences, however, are more subtle and less superficial. Beyond the subtle differences that manifest themselves physically lie the genes that control them. The role of genes in athletics was a topic in a recently published piece in the Journal of Strength and Conditioning Research.
Your genes are a powerful force in your body, but most of them are the same from athlete to athlete. Only a small minority varies from person to person, and these genes account for all the differences you see (or don’t see) between people. Further still, only a subset of these genes might impact your athletic performance.
It might be hard to try to wrap your head around the idea that such a small subset of genes creates all the diversity we see amongst people. We can straighten out part of the confusion right away by distinguishing between gene expression and genetic polymorphism. There’s a big difference between the two, and this study was concerned with the latter.
While most of our genes are the same from person to person, not all of our genes are activated all the time. This means that many of our genes, like light switches, can be switched on or off. We activate a massive number of genes every time we eat a healthy meal (and different genes if we eat a bad meal) or exercise. This phenomenon is called gene expression.
Genetic polymorphism, by contrast, is an actual difference in the physical structure of the gene itself. If two genes are different and neither are expressed, then nothing happens. It’s when these polymorphic genes get activated that differences crop up.
The authors of this study noted that polymorphic variations in over 200 genes have been associated with fitness. To put these numbers in context, thousands of genes are activated just by exercising. One notable gene is called ACTN3 R577X. Don’t worry, you won’t be tested on that later. ACTN3 R577X polymorphism has been related to muscle fiber types, strength levels, and the difference between elite and non-elite performance.
The researchers in the study examined a group of Japanese athletes and tested them for ACTN3 R577X polymorphism. The athletes were then tested for power output. While there was no difference in average power output, there was a significant difference in maximal power output for the men in the study, but not the women. The men with ACTN3 R577X polymorphism exhibited greater power.
So, evidence is mounting that the ACTN3 R577X polymorphism does indeed affect athletic performance. However, some people will use this as an excuse to not exercise, because it’s not in their genes to excel. Differences in your ACTN3 R577X won’t make or break your ability to perform as an athlete, but actually influence your strengths and weaknesses. And besides, there are few things in athletics that get more respect than the “ungifted” athlete who puts their blood, sweat, and tears into being a champion anyway.
1. Naoki Kikuchi, et. al., “The Actn3 R577x Polymorphism Is Associated With Muscle Power in Male Japanese Athletes,” Journal of Strength and Conditioning Research, DOI: 10.1519/JSC.0000000000000338.
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