Should their ACTN3 gene version exclude some of these folks
from marathons? Photo by Monica Darby.
Should I sign Johnny up for football or cross country running? Let me take a quick look at his ACTN3 gene to find out.

This scenario is not as far fetched as it sounds. A genetic test is available that claims to be able to help parents predict what sports their kids will be good at. The idea is that the parents can then funnel their kids into the sports at which they are most likely to succeed. How scary is that!

As I said, the test looks at the ACTN3 gene. Some work has been done that shows that elite athletes with one version are good at sports like football or sprinting. And that elite athletes with another version are good at sports like marathons.

But this gene is just one of many involved in determining how good someone will be at a certain sport. One of the key researchers who identified this gene has written that it can only really account for 2-3% of muscle variation in the general population. In other words, it is just one of many factors involved in making a star athlete.

So this genetic test might be able to distinguish an Olympic athlete from one who doesn't quite make the team. But how many kids does this really apply to?

Even if a genetic test could tell everything about a person's muscles, I would still think it is awful to restrict a child's choices of sports based on that sort of genetic test. Let me give you a hypothetical for why I find this sort of testing so troubling.

Imagine that instead of this test, there is a reliable one that will accurately predict someone's height*. Let's say a family has the test done on their son and they find that he will grow to be 5′3″.

The family steers the boy away from basketball because height is so important in that game. If this actually happened, then the NBA may never have had former pro Mugsy Bogues.

A genetic test that looks at a single trait to determine a person's future is dangerous. Should someone not be introduced into a sport because of their genes? Really?

A genetic test for height won't look at determination. Or speed or ball handling or all of the other traits that made Mugsy such a great player for 16 years.

And the ACTN3 gene test doesn't look at lots of other important traits too. In fact, it won't predict whether your child will be a super athlete or necessarily even good at football vs. a marathon.

Even if a test were developed that looked at all of these traits, should parents use it to control the sports their kids can play? What about their child's interests? Should Mugsy's parents have taken the basketball away from him even though he obviously loved the game?

Just let the kids play! Genes are not destiny.

*This sort of test is a long way off. Scientists only recently found the first "height" gene.

Our QUEST story on the science of anabolic steroids, how they affect the body, and the super-smart sleuths who are using science to catch the cheaters who abuse them, turned up some interesting information. For one thing, I was surprised to learn that according to the National Institute on Drug Abuse's fact sheet about anabolic-androgenic steroids, nearly 2 percent of 10th graders (both boys and girls) admitted to using steroids at some point. Now that may not seem like much, but when you think about the devastating consequences that steroids can have on the body, such as jaundice, kidney failure, and infertility, that's pretty alarming. One could even argue that there's a trickle-down effect when high-school athletes hear allegations of steroid abuse amongst professional athletes and see the athletes continue to pull down multimillion dollar contracts while winning accolades and national titles.

It's nice to know that there are scientists like Terry Sheehan and other high-tech chemists who have the high-tech tools like liquid chromatography and gas chromatography to identify the cheaters in the elite sporting competitions, like the upcoming Beijing Olympics and Tour de France. Clearly the temptation to cheat is great but as the case of Marion Jones has illustrated recently, the fall from grace if you're caught is swift and unremitting. At the end of June, Floyd Landis lost his last appeal to try and hang onto his 2006 Tour de France title. At the time, he vehemently denied that he used testosterone, instead claiming that he naturally has high levels of testosterone. This year's Tour de France has also been riven by positive doping results for several cyclists who tested positive for EPO, a banned substance that is naturally produced by the kidneys and stimulates the production of red blood cells in the bone marrow.

The other thing that I discovered when researching this QUEST story was how prevalent the use of steroids and other performance-enhancing illicit substances are amongst "average" people and amateur/semi-pro athletes. Granted, I can only speak anecdotally but there were quite a few personal trainers in the Bay Area with whom I spoke who mentioned how easily available anabolic steroids and increasingly, Human Growth Hormone (HGH), is in the gym-going and semi-pro cage-fighting and weightlifting community. Nowadays, it's not even necessarily the lure of big bucks or stardom that is enticing people to risk their health by abusing steroids, EPO, HGH or other substances. It seems that the quest for a youthful, fit appearance is enough of a motivator to make some people do so.


Watch the "Science Flexes Its Muscles" TV Story online, as well as find additional links and resources.