Mark Kelly by Mark Kelly

Genetics and HealthActive individuals who wonder why they are not losing weight or getting in shape faster tend to conclude that they are not exercising correctly or need to somehow change their routines. As a result, they often jump on the latest fitness trend in a desperate attempt to reach that weight goal or performance level. Fortunately, new technologies have provided new tools that allow us to look into areas—like our DNA—that may help unlock the keys to better health and performance.

The field of genetics has expanded dramatically in the past few decades and what was once only achievable by a few labs in the nation is now almost commonplace in many small companies or labs. Deciphering and analyzing one's genetic code, however, is somewhat of a two-edged sword. On one hand, our genetics have a strong role in determining how we respond to a given stimulus, such as exercise. On the other hand, our efforts and lifestyle choices generally play an even larger role in our response.

Of course, how we respond to exercise is strongly influenced by our genetics. While it is fairly easy to distinguish a future football linebacker from a long-distance runner, it may be less apparent why two people who seem quite similar can respond so differently to similar exercise training or food intake. In 2010, Dr. James Timmons, a systems biology professor, along with his colleagues at the Pennington Research Center in Louisiana, conducted a landmark study to examine the role of genetics in how the body responds to endurance exercise. The findings from this study led to the creation of a DNA test that predicts how well the body responds to aerobic exercise. This test is now available through a company called XRGenomics for $318-$478, and requires only a inner-cheek swab, which is returned to the company for testing.

Interpreting the results of this test, however, can pose some problems. Dr. Tuomo Rankinen, a genetics professor at Pennington, mentioned that while this test is more reliable than any previous tests in determining VO2 max, it does have some drawbacks. Most importantly, it does not indicate how exercise may affect health-related factors such as blood pressure or insulin sensitivity, or even if an individual will lose weight by exercising. Someone labeled a "low responder" may choose to give up on exercise because they do not consider the health benefits of regular physical activity, such as a lower risk of disease and an overall quality of life.

At ACE, we urge fitness professionals to help their clients live a balanced lifestyle by incorporating regular physical activity and a sensible diet into their daily routines. If your client is considering this type of genetic testing, be sure to remind them that, while genetics play a role in one's responsiveness to certain types of exercise, lifestyle choices are equally—if not more—important.

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