Study: Being Too Thin Could Increase Injury Risk In Female Athletes

NEW YORK (CBSNewYork) -- There's surprising new information about how a woman's weight affects her risk of injury in sports, especially running.

It's not what you might think.

As CBS2's Dr. Max Gomez reported, a new study says that female athletes who are too thin may actually be more likely to get injured.

Most runners figure the lighter they are, the faster they can run.

You'd think that carrying extra weight puts you at a greater risk for injury, but that's not necessarily so.

When it comes to serious tears in knee ligaments, women are five times more prone than men for different reasons.

Competing in seven different track and field events at the collegiate level took its toll on Jordan Moxley. She missed several months due to a stress fracture in her lower leg, and shortly after returning to competition she was sidelined again.

"My first injury was just in the tibia, and then the second, my junior year was in both the tibia and the fibula," she said.

Stress fractures are fairly common in runners, but a new study suggests that one of the reasons that Jordan was injured, may have been her weight. She didn't weigh too much, but too little.

"We could pinpoint some of the predetermining factors that put them at an increased risk of developing a stress fracture as a runner. One of the most important ones being low body weight o low body mass index, or BMI," Dr. Timothy Miller said.

The study at the Ohio State University Wexner Medical Center looked at injuries in dozens of Division I college athletes.

Females with a BMI below 19 had a higher risk for injury than those with normal or even high BMIs, and their injuries took much longer to heal.

The cause is the repetitive pounding on hard surfaces that runners endure.

"There's nowhere for that shock to be absorbed other than directly back into the bone. So until they build some muscle mass, put a little bit of weight back on, they're actually still at risk of developing a stress fracture later on in their career," Dr. Miller said.

Another athletic injury women are five times more prone to than men is ACL tears in the knee. It happened to Cassandra Prenger during her first year of college basketball.

She was devastated by the injury, but she wasn't surprised.

"My senior year of high school we had six ACL tears in one year for like fifteen or sixteen girls," she said.

Many of those injuries could have been prevented. Experts said women should focus on core strength. Doing balance exercises and lifting weights with the backs of your legs could help to avoid a costly injury.

It's not completely clear why women suffer more ACL injuries, some may be due to anatomy -- wider female hips alter the forces on knees. The injury risk may also be due to differences in the way that women's leg muscles fire when they jump and land -- that can be improved with neuromuscular training exercises.