We’ve known for a while many teens aren’t as healthy as they could or should be, and they seem to be getting less healthy with time. However, new stats compiled by the Centers for Disease Control and Prevention confirms this to be true.

According to a 2012 study just released, only 42 percent of teens between the ages of 12 and 15 were as fit as they should’ve been. Girls were especially unhealthy, with barely a third of them classified as healthy. More troubling: Researchers discovered that compared to the same sort of study conducted in 2004, teen health had decreased by about 10 percent.

“Really, this is not good news,” says Janet Fulton of the CDC, who supervised the study. “We’re talking about a better than 1 percent per year drop in cardiorespiratory fitness [among kids for whom] physical activity should come naturally.” (New York Times)

Paul Asay has written for The Washington Post, Christianity Today, Beliefnet.com and The (Colorado Springs) Gazette. He writes about culture for PluggedIn and wrote the Batman book God on the Streets of Gotham (Tyndale). He recently collaborated with Jim Daly, president of Focus on the Family, on his book The Good Dad. He lives in Colorado Springs with wife, Wendy, and his two children. Follow him on Twitter.