The Female Athlete Triad (FAT)

The term Female Athlete Triad, or FAT, was coined in 1992 by the American College of Sport Medicine (ACSM) for a condition seen in female athletes and women including three factors:

  • menstrual dysfunction
  • low energy availability, with or without eating disorders
  • decreased bone mineral density (BMD) and/or osteoporosis

Among the risk factors for FAT we have:

  • participation in sports where appearance is important (gymnastics, ballet, figure skating, diving or body building)
  • participation in endurance sports (distance running, triathlon, swimming, cycling, wrestling or boxing)
  • pressure to lose weight to improve performance
  • competitive personality traits
  • lack of non-sports social relations
  • training while injured, sick or excessively tired.

We are going to focus this post in the three factors affected by FAT, how often they appear and what strategies can be followed to counteract them.


Menstrual dysfunction

The loss of menstruation, or amenorrhea, can be:

  • Primary: when the woman has not experienced her first menstrual period by age 15 although other secondary characteristics have developed.
  • Secondary: when missing three consecutive periods.

In disciplines such as ballet or running the prevalence of secondary amenorrhea can be 69%, compared to a 2-5% range in the general population.  Leptin is a substance associated with fat mass, and its deficiency involved in the amenorrhea of athletes with FAT.

Menstrual dysfunction may lead to infertility, while the low levels of oestrogens can cause endothelial dysfunction, resulting in cardiovascular disease. On top of this, amenorrhoeic athletes have 2-4 times greater risk for stress fracture than controls.


Low energy availability

Irregular eating is frequent among athletes, affecting between 16% to 47% of female elite athletes. Prevalence varies with the sport discipline, age and intensity although levels, are much higher than in the general population (0.5-10% prevalence).

  • The irregular eating of the female athlete doesn´t need to reach the level of a clinical eating disorder, such as anorexia or bulimia, for the FAT to appear. Simply they often lack the appetite necessary to compensate for the energy expenditure from an intense exercise regimen.

Additionally, many female athletes are pressurised to maintain low body weight from coaches, often with poor guidance on healthy dieting and regardless of the method used to attain it.

Low energy availability may have serious effects due to a deficiency in essential amino acids and fatty acids, key in maintaining the body´s ability to build bone, maintain muscle mass, repair damaged tissues and recover from injury. Furthermore, it also has psychological effects, such as depression, low self-esteem and diverse anxiety disorders.


Decreased bone mineral density (BMD) / Osteoporosis

Bone problems are typically the first signs of FAT. The disease is characterized by deterioration of bones tissue, resulting in bone fragility and increased risk of fracture, especially stress fractures.

The prevalence of low BMD in female athletes ranges from 22% to 50%, with osteoporosis affecting up to 13% of them in some studies. This compares to the 12% and 2.3% prevalence in normal population, respectively. Decreased BMD and osteoporosis affect aged woman after menopause, and not healthy athletes at much younger ages.

Healthy athletes tend to higher levels of BMD because of the beneficial effects that physical activity has on it. Nevertheless, when amenorrhea is present their levels of BMD are smaller due to changes in the hormone levels that disrupt bone remodelling and accelerate bone resorption. Thus, menstrual irregularities in young female athletes may counteract the positive effects of physical activity on the bones.



The number of athletes suffering simultaneously the 3 aspects of the triad is quite low. Prevalence is around 4.3% of female athletes, not very far from the 3.4% among healthy controls. Despite this, not all components must be present to suffer negative effects on health.

Women with the triad also have decreased immune function and impaired skeletal muscle oxidative metabolism (worse use of energy sources by the muscles) leading to a decrease of physical performance.



The best approach to the FAT is early detection and prevention. Any female athlete with signs of any of the three components of the triad should be referred to a healthcare professional team, including a sports physician, a nutritionist and a phycologist/psychiatrist. Support from the coaching team and family is important during the rehabilitation process.

The main goal of any treatment is restoring the menstrual cycles and increase the levels of BMD. To do so a change of diet and exercise levels is prescribed to increase overall energy availability. Any improvement is not immediate, and sometimes may not be enough to fully restore bone health.



  • Female athlete triad is a complex syndrome impacting athlete´s wellbeing, at physical and psychological levels.
  • It usually begins with a disturbance of energy balance, and progress towards menstrual and osteoporosis problems.
  • Prevention and education are key factors to avoid the FAT and help maintaining sport practice as a health source.



The Female Athlete Triad

Nazem TG, Ackerman KE

Sports Health. 2012 Jul; 4(4): 302–311. doi: 10.1177/1941738112439685

Photo by Morgan Sarkissian (Unsplash)

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