To witness the power of an elite sprinter or the remarkable endurance of marathoners like Frank Shorter, it’s hard not to be awed by the athletic talent of top athletes. Of course, it brings up the question of whether athletically talented individuals are born that way, by the luck of inheriting certain genes, or the result of lots of training and hard work.
As it turns out, it’s probably some of both. What ultimately can limit an individual’s performance in a sport is genetics, but an athlete will never reach their full genetic potential unless they have the training, motivation, and desire to become the best.
Let’s look at some of the advantages that people who excel in sports can have.
Athletic Talent: Muscle Fiber Types
As you may know, there are two main types of muscle fibers – fast-twitch and slow-twitch. Fast-twitch fibers are those that you predominantly use in sports that require strength and power such as sprinting or jumping. In contrast, slow-twitch fibers are sometimes referred to as “endurance” fibers because, unlike the fast-twitch fibers, they fatigue fast. However, they have the power to contract longer without popping out, although they’re limited in the amount of force they can generate.
Fast-twitch fibers actually come in two varieties or sub-types – type 2a and type 2b. Type 2a fibers are more fatigue resistant than type 2b, giving them some of the properties of slow-twitch fibers. They’re a sort of intermediate fiber between the slow-twitch and fast-twitch type 2b.
Most of us have roughly equal quantities of fast-twitch and slow-twitch fibers. Athletes that are gifted in a certain sport may have an advantage by having more than one fiber type than the other. For example, an endurance runner might have more slow-twitch fibers while a sprinter more fast-twitch ones. A higher ratio of slow-twitch fibers allows a marathon runner to sustain submaximal exercise for a longer period of time, so they can make it over the finish line with a respectable time. In contrast, a sprinter will enjoy the “perks” of having more fast-twitch fibers to really nail short distances.
Although most research suggests you can’t change slow-twitch fibers into fast-twitch ones through training to any significant degree, it does appear that you can change the sub-types of fast-twitch fibers, from type 2a to type 2b and vice versa. Thus, you can become a more proficient sprinter or endurance runner through training although you might not make it to the big leagues.
Is there value to knowing your fiber type ratio, whether you’re predominantly slow-twitch of fast-twitch? Maybe. If a young person has a high ratio of fast-twitch fibers, they might perform best in sports that require strength and power whereas a predominantly slow-twitch individual might aspire to be a championship long-distance runner.
In some countries, they screen for athletic talent early in life so they can send them into an appropriate training program early. Yet trying to predict athletic talent during childhood isn’t very reliable. To truly gauge whether a young person is stronger, faster, or has more endurance than average, a child needs to have gone through their growth spurt. The athletic world is littered with stories of now-famous athletes who were cut from teams when they were nine or ten years old because they weren’t “good enough” but proved to be exceptional later on.
Athletic Talent: Endurance Capabilities
As mentioned, if an individual has a higher ratio of fast-twitch fibers to slow-twitch ones, they may ultimately be a better sprinter than a long-distance runner. Another component of athleticism that’s genetically determined is aerobic capacity or V02 max. Olympic long-distance runners and cyclists often have V02 max readings that are much higher than average, giving them a better capacity to deliver more oxygen to tissues during sub-maximal exercise.
Yet genetics aren’t destiny. Research shows you can improve your aerobic capacity through training and the degree to which a person can do that varies with the average being between 15 and 20%. Still, if you start with a higher baseline V02 max it gives you an advantage in sports that require endurance. Another measure, lactate threshold, also influences athletic performance and can be enhanced through training.
Another variable is to what degree an individual can respond to training. Some people start with a particular baseline aerobic capacity and experience minimal improvement even with focused training. In contrast, another individual may experience a more dramatic increase in V02 max after undergoing training. How well an individual responds to training is genetically influenced. So, your genes influence your V02 max and also impact how much you can change it through training.
Even if you have a high aerobic capacity and lactate threshold, there are other factors that influence how successful you are at endurance sports. If you’re a runner, running economy is a factor. This refers to how much oxygen you need to supply your muscles with to run a certain distance. If you’re not very economical and have lots of extraneous movements when you run, you use up more oxygen for a given distance and have a poor running economy. Of course, motivation is also a factor. Even the best genetics won’t get you very far if you have no desire to be an athlete.
Athletic Talent: Anatomy
What about anatomy? Each of is born with a particular body type or anatomy and certain body types give you an advantage in specific sports. For example, Michael Phelps had the ideal body type for swimming – long, strong arms to propel him easily through the water. He’s also tall with short legs relative to the length of his torso. This type of build is well-suited for swimming. Plus, he’s double-jointed, giving him great flexibility. Although he’s well designed for swimming, the same advantages that help him swim fast would work against him as a powerlifter. Having long arms and being tall is a competitive disadvantage for power-lifting since the weight has to travel farther when you’re taller, thereby limiting the amount you can lift.
Unlike swimmers, successful sprinters tend to have more muscle mass, relatively narrow hips, and a higher ratio of fast-twitch muscle fibers. In contrast, elite long-distance runners are often on the short side and have long, slender legs and high calves. This is a good body type for running long distances, although it won’t make them a top-level runner if they have a low aerobic capacity or no commitment to the sport.
Athletic Talent: Genetics Aren’t Everything
Muscle fiber type, anatomy, and maximal aerobic capacity are genetic factors you don’t have direct control over. You also don’t have absolute control over how much your body responds to exercise training. Yet, these factors aren’t destiny. Championship athletes are both born and made. It’s hard to beat a combination of good genetics, the desire to excel, and true dedication to a sport.
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