How Genetics Influence Athletic Ability

Athletic Ability and Genetics

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What determines athletic ability? And what are the limits of human sports performance? There was a time when no one thought a human could run a four-minute mile, but in 1954, Roger Bannister did just that, and soon, many others followed.

Today, thousands of athletes complete ultra-marathons, Ironman triathlons, and 24-hour races, and athletic records are routinely met and surpassed. Is there any limit? What factors limit human performance in sports?

Many physiologists agree that these factors include nutritionmotivation, environment, and advances in equipment (running shoes, swimsuits, skis, bicycles) that allow for dramatic improvements in athletic performance.

But after you account for these advances, sports performance limits may have to do with genetics. Specifically, the genes that regulate cardiovascular endurance and muscle fiber type are likely to affect athletic ability. 

The Shaping Role of Genetics

Genetics shape us in many ways, including our potential to excel in sports. Training, diet, and other factors play a large role in developing our potential. Genes may help determine what that potential is.

You may have the genetic potential for being a champion athlete, but if you live a lifestyle of overeating and no exercise, you are unlikely to achieve that potential. On the other hand, someone with limited genetic potential can find ways to compensate and become a solid performer.

Genetics have a large influence over strength, muscle size and muscle fiber composition (fast or slow twitch), anaerobic threshold (AT), lung capacity, flexibility, and, to some extent, endurance.

One major limitation for endurance athletes is cardiac capacity, or the heart’s ability to deliver enough oxygen (via the bloodstream) to the working skeletal muscles. This, is largely determined by genetics.

The other limitation for endurance athletes is the ability of muscle tissue to effectively use oxygen and create ATP (adenosine triphosphate), the fuel that allows muscular contraction and movement. The efficiency of this process is measured by VO2 max (maximum volume of oxygen).

How Genetics Influence Training

Your genes may determine how your body responds to training, diet and other external factors. Research on aerobic endurance shows that some people respond more to training than others.

So even if you have a low genetic potential for endurance, you may respond well to training and develop your potential more completely than someone with genetic 'talent' who doesn't respond to training.

Training also increases cardiac efficiency, but the extent of this increase may depend upon genetics. Genetically gifted athletes will have a much greater response to training and will have a large increase in the number of mitochondria in cells.

The mitochondria are organelles in cells that produce ATP. So the more mitochondria a person has, the more efficient they are.

Genetics appear to have less influence over characteristics such as balance, agility, reaction time and accuracy. Many of these skills can be greatly improved with proper training.

Other Factors Affecting Performance

Beyond genetics and training, there are other variables that athletes and their coaches can manipulate to try to improve performance.

Sports Nutrition

An athlete's diet and nutrition plan has an enormous effect on their athletic performance. Nowhere is this more evident than when an elite athlete "bonks" or "hits the wall" during an event.

Bonking is generally a result of glycogen depletion, dehydration, or a combination. Athletes can avoid this by training the body to burn fat when glycogen stores decrease and by continually supplying the working muscles with energy during an event. 

Mental Skills Training

Practicing mental skills training such as imagery, visualization, and learning techniques for dealing with performance anxiety are all skills that any athlete can learn to master with practice.

These techniques, along with learning the tactics and strategies of the sport, using proper equipment and avoiding injuries are all critical factors in sports success that have very little to do with genetics.

A Word From Verywell

Many elite athletes are blessed with the right genetics for their sport and a great training routine. But even recreational athletes can make the most of their abilities with optimal conditioning, good nutrition, and a positive attitude.

4 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Elizabeth Quinn, MS
Elizabeth Quinn is an exercise physiologist, sports medicine writer, and fitness consultant for corporate wellness and rehabilitation clinics.