Many female athletes may be causing irreparable damage to their bodies, even as they train to perfect their sport. These athletes are pushing their bodies while observing the wrong kind of diet, which can develop bone-density disorders.

It's hard to imagine a strong young female athlete having anything in common with a woman in her 70s. But Anne Torres, an elite runner for 12 years learned otherwise from her doctor. "He told me that I had borderline osteoporosis at age 32," says Torres. "That was a huge shock."

"They're 18, 19, 20 [years old]," Nattiv says of the patients she sees, "and they have a hip fracture, just like your post-menopausal grandmother."

Doctors are just beginning to understand this syndrome known as the female athlete triad, often described as "old bones in young bodies." It starts when a young woman pushes herself to swim that extra lap or run that extra mile. And then she dramatically limits what she eats.

"Most of the time, women athletes are told [in order] to get better in their sport, they need to lose weight," says Dr. Carol Otis of the Kerlin-Jobe Orthopaedic Clinic in Los Angeles, who estimates a third of female athletes in sports such as figure skating, running and gymnastics suffer from one or more symptoms of the triad.

Lack of Nourishment Can Stop Menstrual Flow

Otis was one of the first doctors to recognize how over-training and chronic dieting can lead to the second part of the triad: amenorrea, or the point where a woman stops having a period. "The body is conserving energy by turning off the reproductive system and the first sign of that is periods becoming irregular or missing," she explains.

Many mistake amenorrea as a normal part of intensive training. "It didn't bother me I wasn't having a period, to tell you the truth," recalls Torres. "I didn't know there was anything wrong with that."

When a young woman stops menstruating but continues to over-train and under-eat, her body stops making the female hormones needed to build her bones, which leads to the third, most devastating dimension of the triad syndrome: brittle bones that can fracture or collapse.

Dr. Otis inspects an X-ray of a girl suffering from female athlete triad, pointing to the bone which "has become thin enough that it actually has collapsed into a wedge."

"Her posture will be permanently in that position, because the bones have been compressed due to osteoporosis," she adds. Torres can't reverse a decade of bone loss, but to prevent further damage, she stopped running and has changed her eating habits.

Still, thousands of women continue to push themselves, striving for perfection, in both appearance and performance. And doctors worry they will end up with bodies that may look fit, but are dangerously fragile.