No impact or awkward motion foretold the injury, a break through Mary Waechter's left femur. It just cracked; the longest, hardest bone in the body cleaved itself at its weakest point while she was competing on her high school track team.
She suffered a stress fracture, not at all uncommon for intensely athletic females.
Stress fractures and bone injuries, doctors said, often stem from the issues of length and exertion during exercise, running surface, footwear and the still unknown variable of genetics. But in women, this problem can be magnified to an extent unseen in male athletes.
Highly active females sometimes do not get the daily calories needed to support their athletic lifestyle. When that happens, those athletes might stop menstruating. Vital hormones, such as estrogen, are released during menstruation. When females do not receive estrogen and other hormones, it can weaken bone mineral density and leave those women more susceptible to stress fractures.
Waechther's story is representational of this condition -- energy availability, menstrual status, bone mineral density -- known as the female athlete triad.
It is unknown how many females on campus may be affected by the female athlete triad. But those who have suffered stress fractures may not be aware of the female athlete triad or that they might not be receiving the proper amount of calories to support their athletic lifestyle.
"I was a young female athlete and I didn't realize that I needed to be putting in enough calories to support my athletic endeavors," said Waechter, a member of Penn State's triathlon and cross country clubs. "As I'm growing, I was burning energy that way and my body wasn't getting enough energy and I wasn't menstruating on a regular cycle; I was going three, four months at a time without menstruating. They told me this was probably the reason I had this stress fracture in my body, my hormones were off."
The root of the problem often lies within a female athlete's input versus her output, doctors said.
Sometimes female athletes expend more energy than they consume, running miles and training for hours but subsisting on an average- or below-average diet. This can be a result of disordered eating, such as anorexia or bulimia. Sometimes, though, female athletes take in a healthy 2,000-calorie daily total but burn as many as 1,000 calories working out.
"If you're running 26 miles, you don't want to carry a lot of extra pounds," Dr. Anne Loucks of Ohio University, who helped author the American College of Sports Medicine's latest position paper on the issue, said in a telephone interview. "Some of these women are trying to be as light as possible. They don't have an eating disorder, they just don't eat enough for what they're expending."
Low caloric energy can reduce the release of hormones important for bone strength and stop the menstrual cycle in a condition known as amenorrhea. The body may stop menstruating as a survival technique, shutting down non-essential functions such as reproduction in order to sustain itself. The lowered estrogen and hormone levels often result in decreased bone mineral density and strength, thus leaving certain female athletes at risk to stress fractures.
Problems with bone density at a young age could also be damaging in the future, Dr. Nancy Williams, an associate professor of kinesiology at Penn State, said in a recent interview.
The body stops increasing its bone mass in the early 20s. The process of resorption, the leaching of calcium from the bone, weakens the bones over a number of years. Females who do not reach peak bone mass will be susceptible to fractures -- the theoretical point known as the fracture threshold -- at an earlier age than females who appropriately peaked in their youth.
Williams and Dr. Mary Jane De Souza, a recently hired Penn State kinesiology professor, are trying to organize a yearlong research program to study the impact of caloric intake on bone health and the menstrual cycles in exercising women. They are also trying to start up a female athlete triad task force, with a hotline and educational programs for athletes on campus.
In the 1980s, doctors began obtaining information that there happened to be more menstrual disturbance in athletes than non-athletes. First reports of altered bone density were also released during that time. The term female athlete triad was first coined in 1992 by the American College of Sports Medicine, which first released a position report on the condition in 1997 and revised it in the fall of 2007.
"There's definitely a recognition that this is a problem, that females are at risk just because of the huge energy expenditures at risk in competitive sports," Dr. Liz Joy, a female medicine and sports medicine physician at the University of Utah, said in a telephone interview. "Do we still see athletes that come in are being told not having their period is normal? Yes. But in the last 10 to 15 years I have seen a considerable decrease."
Penn State's varsity track teams have not had much difficulty with stress fractures related to the female athlete triad, coach Beth Alford-Sullivan said.
"If an athlete's healthy and taking care of themselves and training at the correct intensity and correct volumes, it really shouldn't be a factor," she said. "If those things are out of whack, the female athlete triad might play out as being the reason the injury, their injury was created or comes about. But in reality, what we try to do is produce a healthy environment. We have a lot of resources between our doctors, trainer and nutritionists."
Waechter, the Penn State junior participating with the cross country and triathlon clubs, suffered her first stress fracture, a break in her left tibia, during the fall of her junior year of high school. She recovered and returned for the spring track during her junior year. But after just a few weeks of training for the spring season, Waechter felt pain in her left thigh. It turned out to be a stress fracture in her femur.
"It took a long time to diagnose," she said. "I actually ran on it three weeks after I had the pain. It didn't cross anybody's mind that my femur was broken. They weren't even thinking that. They thought it was my quadriceps or hamstring."
Prior to her injuries, Waechter trained intensely but only ate three meals a day: a big bowl of cereal with fruit for breakfast, maybe a peanut-butter-and-jelly sandwich for lunch and a home-cooked dinner each night.
By most normal standards, Waechter was consuming enough calories. But, when combined with her workout regimen, her intake amounted to very little. In turn, Waechter said, she lost her period for months at a time, which weakened her bone strength.
Despite her high school difficulties with the female athlete triad, Waechter remains committed to running. She trains six days a week in anticipation for triathlon and cross country competitions with her Penn State club teams. She runs about six to eight miles each workout day, swims for an hour about twice a week and bikes about 30 miles twice a week.
So even though she still works out regularly, she now she eats six meals a day: breakfast, lunch and dinner, with substantial snacks after each.
"I was learning and being educated in this experience," Waechter said. "I learned that's OK for the normal person who is living on a 2,000-a-day diet, but when you're burning over 1,000 calories, you need to replace what you're burning to get up to 2,000."
