What Is the Female Athlete Triad?
As the name suggests, the female athlete triad consists of three medical conditions: 1). energy imbalance with or without an eating disorder, 2). menstrual disturbances, and 3). decreased bone mineral density with or without osteoporosis. The three symptoms that make up the female athlete triad can occur alone or in combination; however, the key to treatment of this condition is early diagnosis and treatment before serious consequences develop. The female athlete triad is quickly becoming a very common condition in active teenage girls and young adult women. Often a low-calorie diet is the first sign of an eating disorder; however, excessive exercise or compulsive exercise can also be another sign. The low-calorie diet also makes it difficult for the athlete to get enough calcium and vitamin D which can also contribute to low bone density. 

Who Is At Risk For The Female Athlete Triad?
Teenage girls who restrict their eating and have amenorrhea are at the highest risk for female athlete triad. Although most people immediately think of female distance runners when thinking about the female athlete triad, they are not the only female athletes where the female athlete triad is found. Female athletes who compete in dance, gymnastics, figure skating or other sports where an athlete may try to reach a low body weight are more likely to have amenorrhea, as are those who compete in scoring sports such as gymnastics and figure skating.

Bone Mineral Density Testing
Decreased bone mineral density (BMD) is a key element of the female athlete triad.  A key tool in the diagnosis and treatment of the female athlete triad is the dual X-ray absorptiometer (DXA).  A DXA utilizes two X-ray beams; with different energy levels to measure an individual’s BMD. The test provides an accurate measure of BMD throughout the body and at key areas of the body (i.e., hips, spine, etc.).  

The International Society for Clinical Densitometry (ISCD) recommends that BMD in women be expressed as Z-scores to compare similar age and sex (ISCD, 2004).  The ISCD states that a woman with a Z-score below -2.0 has low BMD.  The American College of Sports Medicine (ACSM) recommends a different standard for female athletes. ACSM  considers low BMD for female athletes to be a BMD Z-score between -1.0 and -2.0 (ACSM, 2007) and a history of nutritional deficiencies, stress fractures, and/or other secondary clinical risk factors for fracture ( Khan et al., 2004, ISCD, 2004; Khan et al., 2006). The reason for the lower BMD Z-score is that female athletes in weight-bearing sports typically have a BMD that is 5–15% higher than non-athlete females (Fehling et al., 1995; Robinson et al., 1995). Therefore, for female athletes with a BMD Z-score < -1.0 further investigation is warranted, even in the absence of a prior fracture (ACSM, 2007). It is also recommended that individuals with a history of estrogen deficiency or eating disorders for a cumulative total of 6 months or more, and/or a history of stress fractures or fractures should have a DXA scan to determine an individual’s BMD (Khan et al., 2006). 

Following the initiation of a treatment plan, reevaluation is recommended in 12 months (ACSM, 2007).  Since there are slight differences in the three manufactures of DXA devices, it is recommended that serial DXA studies be obtained on the same machine.

Prevention and Treatment Recommendations
Since the female athlete triad is a multifactorial issue the prevention and treatment of it should employ a multidisciplinary team. This team should include a physician or other health-care provider (physician’s assistant or nurse practitioner), a registered dietitian, and for athletes with disordered eating or an eating disorder, a mental health practitioner. Additional valuable team members may include a certified athletic trainer, an exercise physiologist, and the athlete’s coach, parents and other family members (ACSM, 2007).  Early identification and education are key to successful treatment of the female athlete triad.  Athletes with menstrual disorders and/or low energy availability with or without disordered eating or eating disorders should be educated about the risk of impaired bone mineral accrual, declining bone mineral density, osteoporosis, and stress fractures. DXA scans are an important piece to the treatment puzzle, as the accurate and precise body composition measurements, including BMD, can help the treatment team monitor changes, and ideally, improvements, over time (ACSM, 2007).

References
American College of Sports Medicine. (2007). The female athlete Triad. Medicine and Science in Sports and Exercise 39:1867-1882.

Fehling PC, Alekel L, Clasey J, Rector A, Stillman RJ. (1995). A comparison of bone mineral densities among female athletes in impact loading and active loading sports. Bone 17:205–210. 

International Society For Clinical Densitometry Writing Group For The ISCD Position Development Conference. (2004). Diagnosis of osteoporosis in men, women, and children. Journal of Clinical Densitometry 7:17–26.

Khan AA, Bachrach L, Brown JP, et al. (2004).  Standards and guidelines for performing central dual-energy x-ray absorptiometry in premenopausal women, men, and children. Journal of Clinical Densitometry 7:51–64.

Khan AA, Hanley DA, Bilezikian JP, et al. (2006). Standards for performing DXA in individuals with secondary causes of osteoporosis. Journal of Clinical Densitometry 9:47–57.

Robinson TL, Snow-Harter C, Taaffe DR, Gillis D, Shaw J, Marcus R. (1995). Gymnasts exhibit higher bone mass than runners despite similar prevalence of amenorrhea and oligomenorrhea. Journal of Bone and Mineral Research 10:26–35.

About the Author
Donald Dengel, Ph.D., is a Professor in the School of Kinesiology at the University of Minnesota and is a co-founder of Dexalytics. He serves as the Director of the Laboratory of Integrative Human Physiology, which provides clinical vascular, metabolic, exercise and body composition testing for researchers across the University of Minnesota.