GENES AND SPORT: ARE YOUR PARENTS RESPONSIBLE FOR YOUR WINS AND LOSSES?

James S. Skinner, Ph.D.
Department of Kinesiology
Indiana University
Bloomington, Indiana

We all know of champion athletes whose parents and perhaps grandparents were also champions.

Moreover, racehorse owners spend millions of dollars on stud fees to breed winners. This seems to tell us that champions are born and that if you don't have the "champion gene," you can never be truly successful, no matter how hard you train. In other words, you must be wasting your time practicing your favorite sport if your parents were not champions themselves. But if champions can be bred, why don't all racehorses bred for performance become champions? The reason is that there are factors other than heredity that play important roles in performance, too.

Genes Are More or Less Important

There is no getting around it; genes determine our potential for developing many of the structural and functional characteristics important in determining sport performance. For instance, to be a successful center in the National Basketball Association, you must inherit the gene for tall stature. For other characteristics, though, diet, training, and other environmental factors play a huge role in how your genetic potential is expressed. For example, you may have the genetic potential for a low body weight, but eating too much and exercising too little can overcome that genetic message and cause you to become obese. Thus, some characteristics like height are strongly influenced by genes, whereas others like abdominal girth are less affected by the genes and are more likely to be influenced by the environment. Table 1 illustrates how strongly the genes typically affect some of the structural, functional, and performance characteristics of the body. Those characteristics in the table for which the genes have only a low to moderate effect (e.g., balance, reaction time, accuracy of movements) are likely to be more powerfully influenced by training, diet, and other environmental factors than are characteristics like strength and flexibility, for which the genes have a large effect.