One of the best ways to build strong bones in female athletes is regular participation in weight bearing exercise, like running and jumping. In fact, females who participate in sports like soccer or basketball tend to have stronger bones than swimmers or cyclists. However, the benefits of weight bearing activity on bones are lost if the athlete does not have an adequate nutritional status. This is because there is a critical relationship between the nutritional status, menstrual function and bone strength in female athletes knows as the Female Athlete Triad.
The Female Athlete Triad was first discussed in the medical literature in the 1990's. Several researchers and medical professionals had noticed that highly physically active females were sustaining increased amounts of stress fractures in bones in the legs and feet. When they looked further, many of these women reported menstrual irregularity or not having any periods at all. Further research has demonstrated that the problem is not the intensity or frequency of physical activity, but that some women don't have adequate caloric intake to support this level of activity without stealing calories from other important processes such as building bone, regulating body temperature or sustaining menstruation. While some women with the Female Athlete Triad have eating disorders, such as anorexia, many of them are not aware of how many calories they need to eat for the level of activity they are involved in.
The short-term problems with the Female Athlete Triad are recurrent stress fractures which can be frustrating and make it difficult for women to participate in their sports. However, potential long-term problems include infertility and complete fractures of the spine, hip and wrist as older females.
One of the best ways to identify women at risk for the Female Athlete Triad is to ask questions about dietary habits and menstrual history. Women who are highest risk for the Female Athlete Triad are those who did not start menstruating until the age of 15 years or later, women involved in leanness or aesthetic sports (cross country, gymnastics, ballet) and women who have recently increased their athletic intensity (such as females transitioning from high school to college sports). Active females should monitor their menstrual cycles and have an evaluation with a sports medicine physician or their primary care doctor if they start to have irregular periods (>38 days between periods) or stop having periods. Women who are using hormonal contraceptives (birth control pills, patches or rings) might be masking menstrual irregularity, so they need to be extra careful that they are eating enough to maintain their level of physical activity.
The diagnosis of the Female Athlete Triad is often made with questionnaires, a physical examination and diagnostic testing. Once diagnosed, the treatment usually focuses on nutritional counseling and rehabilitation for the stress fracture, if this has occurred. Fortunately, most women recover well with a team based treatment approach and often note that their performance and overall health improve once their nutrition is improved.
Bottom line: Adequate nutritional intake is critical to optimize health and performance in female athletes. If female athletes do not eat enough calories, they can suffer stress fractures and recurrent injury. It is not normal for female athletes to miss menstrual periods, and if this occurs, they should be evaluated by a sports medicine physician to avoid developing the Female Athlete Triad and stress fractures.