As the world of sport has embraced the participation of women and girls, the incidence of health problems that pertain specifically to premenopausal female athletes has increased significantly. One of these is the female athlete triad, which consists of 3 interrelated medical conditions associated with athletic training:
- Disordered eating.
Because female athletes are pressured both by societal ideals of attractiveness and the weight standards set by certain sports, they often are preoccupied with body weight. The triad occurs in all sports, but especially those in which low body weight is emphasized for appearance and/or performance, such as running, swimming, diving, ballet, gymnastics, and figure skating.
This increasingly common disorder can have life-threatening consequences-yet too often it goes unrecognized, and the opportunity for early intervention is missed. In this article, we will discuss the warning signs and symptoms of the female athlete triad and also present the latest approaches to treatment and prevention.
UNDERSTANDING FEMALE ATHLETE TRIAD
The American College of Sports Medicine (ACSM) identified the female athlete triad in 1992.2 In 1997, the ACSM published the first position paper on the triad, which defined the condition, outlined treatment options, and called for a more concentrated effort at prevention.2 In 2000, to address growing concerns regarding female athletes-particularly adolescents-the American Academy of Pediatrics published a policy statement on the triad.3
Disordered eating. This is the central aspect of the triad. When the triad was initially described, the term "eating disorder" was reserved for the clinical diagnoses of anorexia nervosa and bulimia nervosa as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria of the American Psychiatric Association (APA).4 Many athletes did not necessarily meet all the criteria for an eating disorder, yet still exhibited pathogenic weight control behavior. For example, their body weight might not have met the DSM-IV criterion for anorexia or bulimia nervosa (more than 15% below normal weight).4 Athletes' weight may seem to be adequate because of the in- creased muscle mass that training has produced.
Thus, the term "disordered eating" was adopted for the female athlete triad to avoid underdiagnosis. Since then, the APA has recognized that its criteria for eating disorders excluded many women with abnormal eat- ing patterns (not just athletes). They consequently added the diagnosis "eating disorder not otherwise specified."4 Table 1 lists the criteria for this diagnosis.
The prevalence of anorexia nervosa in the general population is approximately 1%; that of bulimia nervosa, 1% to 3%.4 However, among female athletes, the frequency both of eating disorders that meet DSM-IV criteria and of pathogenic weight control is between 15% and 62%.2,5-8 This wide range can be attributed to differences in the percentages associated with various sports and to different definitions of disordered eating.
Despite their increasing prevalence, eating disorders may remain clinically undetected in up to 50% of cases.9 The potential warning signs of disordered eating include:
- Ritualized eating.
- Food restriction.
- Obsessive training.
- Other compulsive behavior.
Amenorrhea. Female athletes are at significant risk for amenorrhea; these young women have a higher prevalence of delayed menarche, primary amenorrhea, and secondary amenorrhea. The prevalence of amenorrhea in the general population is 2% to 5%, but in athletes it ranges from 4% to 66%.5-8,10,11 Again, the variability results from differences in the populations of women who have been studied. The highest frequency is seen in ballet dancers and runners.
Amenorrhea in female athletes results from hypothalamic dysfunction.12 Until recently, the accepted physiologic explanation of the origin of this dysfunction was the "caloric deficit" or "energy drain" theory. According to this theory, disturbance in menses results when the caloric intake is insufficient to maintain the endocrine components of the female reproductive system. The most current explanation is the "energy availability" theory. This theory holds that when the CNS detects that dietary energy intake is not sufficient to support both exercise and other physiologic functions, it reduces energy expenditure by suppressing reproductive function.13 Luteinizing hormone pulsatility is lost, which results in low estrogen levels and a hypogonadal state.12
Osteoporosis. Premature bone loss or inadequate bone formation results in low bone mass, increased bone fragility, and increased risk of fracture. Osteoporosis can affect all skeletal sites.14,15 Below is the classification of bone density according to World Health Organization criteria16:
- Normal: bone mineral density (BMD) less than 1 SD below the young adult mean.
- Osteopenia: BMD 1 to 2.5 SD below young adult mean.
- Osteoporosis: BMD greater than 2.5 SD below young adult mean.
Female athletes with amenorrhea have low bone density as a result of their hypoestrogenic state.8,17,18 The prevalence of osteoporosis among female athletes is unknown, and not all athletes with a history of amenorrhea will experience osteoporosis. However, studies have shown that lumbar bone density in amenorrheic athletes is 14% less than that of eumenorrheic athletes and 27% less than that of sedentary women with normal cycles.18
Osteoporosis in a young athlete is alarming because it indicates that bone density is declining at a time when peak bone mass should be forming. Until recently, it was believed that peak bone mass was achieved around the age of 30 years. Recent studies suggest that peak bone mass is actually achieved between 18 and 25 years of age.11,19 This may mean that younger female athletes with decreased bone density never reach optimal levels of peak bone mass-which puts them at risk for premature osteoporosis, stress fractures, and later fractures of the hip and vertebrae.
Isolated stress fractures are a common complication of the female athlete triad and may serve as a warning sign. Stress fractures are a common overuse injury. Epidemiologic data have shown that they occur more frequently in women than in men20-22; however, they may be seen in healthy menstruating athletes as well as in patients with the triad. The actual incidence in women with female athlete triad is not known. Runners, gymnasts, dancers, swimmers, rowers, and lacrosse and basketball players may all be affected; the greatest reported incidence is in runners. Stress fractures account for 4.4% to 15.6% of all injuries to runners.20
Studies have shown that BMD increases when the menses resume.23 However, this increase lessens over time, and the BMD of previously amenorrheic athletes often remains below normal for their age.17,23 This fact underscores the importance of early intervention when any aspect of the female athlete triad is suspected.