Stress fracture could portend Female Athlete Triad

Like any other machine, your body won't function properly without the right fuel.

Athletes should know this better than anyone. But social pressure to be thin — or just lack of awareness about nutrition — can lead to not eating enough, especially for some female athletes.

Many factors go into calculating how many calories a person needs every day. Take two women of similar height and weight. If one of them is an athlete training for a marathon, she will need substantially more calories to keep her engine running than her more sedentary sister. Without that fuel, her body starts to conserve energy, sometimes in ways the woman might not realize at first.

"It's a domino effect," explains Tricia M. Beatty, a sports medicine physician at the Rothman Institute. "The first system to shut down is the female reproductive system. Then the combination of low estrogen and nutrients being leached from the bone to compensate can lead to osteoporosis."

This triple threat of energy deficiency, low bone mineral density and abnormal menstrual cycles is known as the Female Athlete Triad.

It often presents first as a stress fracture. Left unchecked, the triad can snowball into complete fractures of the spine or hip, in addition to reproductive and other problems.

The triad is most prevalent in sports like ballet, gymnastics and cross-country, but it can affect other athletes too. When it was first defined in the 1990s, it was thought to be associated with eating disorders like anorexia and bulimia. However, doctors have often found that female athletes simply don't know how much they should be eating.

"Energy availability is the core component of the triad," explains Kate E. Temme, assistant professor of sports medicine in the Perelman School of Medicine at the University of Pennsylvania. "When an athlete doesn't eat enough to support the amount of energy she expends in her sport, insufficient energy remains to sustain normal biologic functions. Endocrine systems shut down, affecting metabolism, bone and reproductive health."

"We see many overuse injuries in these athletes because they don't have sufficient nutrition for adequate healing," adds Temme. "Nutritional optimization can improve performance and help prevent athletes from being sidelined by injuries."

Teenage girls are especially susceptible. In the teen years, girls build up their peak bone mass, so it is crucial to correct any imbalances early in order to prevent long term side effects like infertility and osteoporosis haunting them later in life.

When a female athlete presents with a stress fracture, Beatty says, "It is important to have high clinical suspicion and to be on the lookout for the triad."

Bottom Line: If you are a female athlete and your menstrual cycle is irregular (but you are not pregnant), see a physician to be evaluated.

Read more Sports Doc for Sports Medicine and Fitness.