fit rx [ performance ]
Are Athletes Born or Built?
The influence of genetics on athletic ability and success
By robert vu
thletic records are broken year after year, and the limits of human performance continue to be debated. Just as soon as we think something can’t be done, someone comes along and shows us that indeed it can. There was a time when nobody thought a human could run a fourminute mile. Roger Bannister did that in 1954 and soon others followed. Ultra marathons, ironman triathlons, and 24-hour races are now commonplace. Surely there must be some end. So what factors limit performance? Most physiologists agree that the current limits have to do with our genetics, specifically genes that regulate our cardiovascular endurance and muscle fibre type; but some factors are much more variable. Things like nutrition, motivation, environment, and advances in equipment (running shoes, swim suits, skis, and bicycles) all allow for dramatic improvements in athletic performance. Genetics and Sports Performance 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, but our genes might also limit performance. 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,
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muscle size, and muscle fibre 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, too, is largely determined by genetics. Another 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 something called VO2 max (maximum volume of oxygen). How Genetics Influence Training Response Your genes might also determine how your body responds to training, diet, and other external factors. Research on aerobic endurance shows that not everyone responds to training in the same way. Even if you have a low genetic potential for endurance, it is still possible to develop your full potential, perhaps more so than an athlete with high genetic potential but low response to training. Training increases cardiac efficiency, but the extent of this increase may depend on 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 that produce ATP, so the more mitochondria a person has, the more efficient they are.)
Other Factors That Affect Sports Performance 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 the proper training. Sports Nutrition An athlete’s diet and nutrition plan has an enormous affect 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 of both. 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 imagery and visualization and learning techniques for dealing with performance anxiety are skills that any athlete can 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 athletic success that have little to do with genetics. Although many elite athletes are blessed with the right genetics for their sport and a great training routine, even recreational athletes can make the most of their abilities with optimal conditioning, good nutrition, and a positive mental attitude.?
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july/august 2013
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7/9/13 12:10 AM