Instead of "worrying researchers", this should be encouraged! Muscle burns fat (you know, that bad stuff) and the way to build it is to do physical labor (which almost no one does anymore) or lift weights. Using steroids is bad of course, but there is NO reason to discourage kids (or adults!) from packing on muscle!

At least these teens aren't sitting on the couch eating chips and fast food. What doesn't worry researchers these days? What's more concerning, "Teen desire to look 'buff' worries researchers" or "Teen desire to look 'obese' worries researchers?" c'mon figure it out.

If youth want to build muscle, I'm all for it. It's easier than waiting until you're 40 and trying to undo years of abuse to your body. Looking back at history teens were more muscular from doing farm and manual labor, now they just sit around while food is brought to them as they play video games.

The problem is that, in addition to people doing healthy activities, the goal of having a particular look is what creates the problem. If it's a look they are after there are a million unhealthy fad ways to do that. Why are the Asian kids more likely to use steroids? Could have something to do with the way different ethnic groups produce different types of muscle...

Have we really gotten so obese as a country that we worry about kids wanting to look fit and muscular? Look at the Greek sculptures, lots of fit and muscular people. That's what a human should look like, not fat.

I love how researchers think they are on to a new phenomenon, and how the media thinks it's reporting some earth-shattering new information. While reading this story it brought me back to my senior year of high school in 1982. My fellow (teenage) male classmates wanted the exact same thing back then as the teenagers mentioned in this story; the only difference from then and now is that back in my day anabolic steriods were not yet listed as a Schedule III drug on the Federal Controlled Substances Schedule.

the problem is working out with anything more than bodyweight before or during puberty 'stunts' growth (energy shifts from skeleton to muscle growth). Some people mature faster than others, but most kids shouldn't lift more than their bodyweight until they are at least 15, at least after their first pubescent growth spurt is completed. Then their bones and more importantly their muscle connective tissue is mature enough to handle the load. I agree that we should have a fitter community, but get your kids into activities, and off the couch, not into the iron room. 3 hours of flag football or soccer is better than an hour lifting for any kid until they shaving.

Seriously? First they b*tch about kids being obese. Then they b*tch about kids working out? There is nothing unhealthy about muscle building, except for steroid use (of course). Muscle building itself is NOT an unhealthy activity, and is actually even healthier than the goal of trying to be too thin, which usually comes about from near starvation, which depletes heart muscle tissue. Since we're no longer an agrarian society where kids would be doing hard manual labor on the farm (oftentimes in lieu of attending school), let them work out, for crying out loud! It's what the body is meant to do!

Thank you gbrunkhorst for restating the point of the article so many seem to have missed. Body building/weight lifting at too young of an age can have negative consequences. The researchers/point of the article isn't to discourage kids from excerising, it is to educate them and adults how the body works with regards to building muscle mass and risk of doing so before puberty. This isn't new information as I recall being educated in health class in the 1980's on this as well. Hopefully some of today's posters can reread the article without such a sinister view of the world.

Alcohol use and abuse is far worse than steroids. And at most 5% steroid use among the lifters, that is not the biggest problem to worry about.