Sept. 20, 2005

John M. MacKnight, MD UVA Sports Medicine

Girls who play soccer, or participate in any endurance sport, are at risk to develop a combination of three disorders now commonly referred to as the "female athlete triad." This triad is composed of eating disordered behaviors, exercise-associated loss of normal cyclic menstrual periods (amenorrhea), and premature loss of bone mineral density or frank osteoporosis. This disorder is increasingly recognized in athletic women, particularly as more and more girls are participating in high level sports and are starting at increasingly younger ages. The physical stresses associated with this activity pattern are at the heart of this serious disorder.

Causes

Traditionally, this disorder has been considered a result of weight loss from a combination of high levels of training and low calorie consumption, particularly amongst girls who were overly conscious of their weight. Many young ladies are under the false assumption that having lighter body weight will enhance performance. Though this is certainly true with respect to carrying excess body weight, the notion that light body weight is always an advantage is incorrect.

Studies have now clearly shown that it is a negative calorie balance (more calories burned than taken in each day) rather than low body weight that contributes most significantly to the female athlete triad. Even exceedingly thin women who meet their energy requirements each day are protected from developing features of the triad. The individual components of the triad are further addressed below.

Disordered Eating

Disordered eating (a pattern of poor nutritional practices arising largely from poor food choices and a lack of knowledge about the importance of nutrition to performance) and distinct eating disorders play a prominent role in generating a deficit of necessary calories for growth, development, and activity referred to as negative calorie balance. This is one of the components of the female athlete triad. As noted above, many athletic girls are overly concerned about body weight and assume that being lighter will be beneficial to their athletic endeavors. This preoccupation with weight often leads to disordered eating behaviors such as meal skipping, overly exclusionary diets (protein predominant with low fat and minimal carbohydrate which is absolutely contrary to a desirable intake pattern for an athlete), and excessive exercising to foster additional weight loss or compensate for the food that they have eaten.

Some of these athletes will progress on to a frank eating disorder such as anorexia nervosa or bulimia nervosa. Anorexia is characterized by severe calorie restriction and/or excessive exercise in order to lose weight in response to a distorted sense of being "fat" in spite of often being excessively thin. Bulimic individuals often binge eat and then induce vomiting in response to the food that they have consumed. These individuals harbor great guilt about their eating habits but tend to be of normal body weight. The stress that such eating disorders place on the body is considerable and is only magnified in highly active individuals. If these behaviors result in a negative calorie balance, menstrual disturbances may ensue.

Amenorrhea

Amenorrhea is defined as the absence of normal menstrual cycles. Primary amenorrhea is the failure to start having regular menstrual cycles while secondary amenorrhea is the cessation of previously established menstrual cycles. In the setting of physical stress such as calorie deficiency and high levels of physical training, the normal cyclic hormonal patterns in young ladies become disturbed or are completely disrupted. The most important of these is a relative deficiency in estrogen. Low levels of estrogen negatively influence the development and maintenance of bone mineral density in exercising girls. This is particularly important in light of the fact that young women can actively add to their bone density only until age 30-35. If they fail to establish strong bone health when young, they are at great risk to develop osteoporosis later in life (see below).

A vital part of any pre-participation screening is assessing whether a young lady has any degree of menstrual dysfunction. Although menstrual irregularity is not uncommon in athletes in general, a significant decrease or loss of menstrual function should always raise suspicion of the female athlete triad and a risk for its other components.

Osteoporosis

Osteoporosis refers to abnormal loss of bone density resulting from a greater rate of bone breakdown than bone formation. This is a complex process but in athletes the most important contributing factors to bone health are adequate intake of calcium and vitamin D and adequate estrogen levels. As such, female athletes who are estrogen deficient and nutritionally depleted because of poor eating habits are at great risk to develop bone thinning or even osteoporosis. The significance of this change in bone health has both short and long-term ramifications.

During their athletic career, women with low bone density are at increased risk for sports-associated stress fractures. Later in life, low bone density at a young age predisposes to the development of frank osteoporosis, particularly after menopause. Bone density does respond favorably to weight-bearing exercise; consequently, many athletes feel that their training activities are sufficient to foster normal bone health. However, if the other factors of disordered eating and amenorrhea are present, weight-bearing exercise may not only fail to help bone density but may actually contribute to stress fractures.

Girls who play soccer, or participate in any endurance sport, are at risk to develop a combination of three disorders now commonly referred to as the "female athlete triad." This triad is composed of eating disordered behaviors, exercise-associated loss of normal cyclic menstrual periods (amenorrhea), and premature loss of bone mineral density or frank osteoporosis. This disorder is increasingly recognized in athletic women, particularly as more and more girls are participating in high level sports and are starting at increasingly younger ages. The physical stresses associated with this activity pattern are at the heart of this serious disorder.

Causes

Traditionally, this disorder has been considered a result of weight loss from a combination of high levels of training and low calorie consumption, particularly amongst girls who were overly conscious of their weight. Many young ladies are under the false assumption that having lighter body weight will enhance performance. Though this is certainly true with respect to carrying excess body weight, the notion that light body weight is always an advantage is incorrect.

Studies have now clearly shown that it is a negative calorie balance (more calories burned than taken in each day) rather than low body weight that contributes most significantly to the female athlete triad. Even exceedingly thin women who meet their energy requirements each day are protected from developing features of the triad. The individual components of the triad are further addressed below.

Disordered Eating

Disordered eating (a pattern of poor nutritional practices arising largely from poor food choices and a lack of knowledge about the importance of nutrition to performance) and distinct eating disorders play a prominent role in generating a deficit of necessary calories for growth, development, and activity referred to as negative calorie balance. This is one of the components of the female athlete triad. As noted above, many athletic girls are overly concerned about body weight and assume that being lighter will be beneficial to their athletic endeavors. This preoccupation with weight often leads to disordered eating behaviors such as meal skipping, overly exclusionary diets (protein predominant with low fat and minimal carbohydrate which is absolutely contrary to a desirable intake pattern for an athlete), and excessive exercising to foster additional weight loss or compensate for the food that they have eaten.

Some of these athletes will progress on to a frank eating disorder such as anorexia nervosa or bulimia nervosa. Anorexia is characterized by severe calorie restriction and/or excessive exercise in order to lose weight in response to a distorted sense of being "fat" in spite of often being excessively thin. Bulimic individuals often binge eat and then induce vomiting in response to the food that they have consumed. These individuals harbor great guilt about their eating habits but tend to be of normal body weight. The stress that such eating disorders place on the body is considerable and is only magnified in highly active individuals. If these behaviors result in a negative calorie balance, menstrual disturbances may ensue.

Amenorrhea

Amenorrhea is defined as the absence of normal menstrual cycles. Primary amenorrhea is the failure to start having regular menstrual cycles while secondary amenorrhea is the cessation of previously established menstrual cycles. In the setting of physical stress such as calorie deficiency and high levels of physical training, the normal cyclic hormonal patterns in young ladies become disturbed or are completely disrupted. The most important of these is a relative deficiency in estrogen. Low levels of estrogen negatively influence the development and maintenance of bone mineral density in exercising girls. This is particularly important in light of the fact that young women can actively add to their bone density only until age 30-35. If they fail to establish strong bone health when young, they are at great risk to develop osteoporosis later in life (see below).

A vital part of any pre-participation screening is assessing whether a young lady has any degree of menstrual dysfunction. Although menstrual irregularity is not uncommon in athletes in general, a significant decrease or loss of menstrual function should always raise suspicion of the female athlete triad and a risk for its other components.

Osteoporosis

Osteoporosis refers to abnormal loss of bone density resulting from a greater rate of bone breakdown than bone formation. This is a complex process but in athletes the most important contributing factors to bone health are adequate intake of calcium and vitamin D and adequate estrogen levels. As such, female athletes who are estrogen deficient and nutritionally depleted because of poor eating habits are at great risk to develop bone thinning or even osteoporosis. The significance of this change in bone health has both short and long-term ramifications.

During their athletic career, women with low bone density are at increased risk for sports-associated stress fractures. Later in life, low bone density at a young age predisposes to the development of frank osteoporosis, particularly after menopause. Bone density does respond favorably to weight-bearing exercise; consequently, many athletes feel that their training activities are sufficient to foster normal bone health. However, if the other factors of disordered eating and amenorrhea are present, weight-bearing exercise may not only fail to help bone density but may actually contribute to stress fractures.

Screening/Diagnosis/Treatment

With increasing numbers of girls participating in organized sports at high levels, anyone involved in the care and development of these athletes must be vigilant for features of the female athlete triad. Preparticipation screenings are designed to include questions that may assist in the recognition of the female athlete triad. Warning signs include an athlete's obsessive control of their eating behaviors, rapid and progressive weight loss, fundamental change in monthly menstrual patterns with either irregularity or loss of normal menstrual periods, and repeated stress fractures. These features should always prompt an evaluation by the team physician or personal primary care physician.

Management of female athlete triad associated with unintentionally poor nutritional status (disordered eating) is primarily the role of the sports nutritionist with support from a physician. Correction of the inadequate calorie consumption generally resolves the triad completely. If a frank eating disorder is present, a team of treating specialists including a psychiatrist/psychologist, team/primary care physician, and sports nutritionist is essential for adequate management. Athletic participation often must be limited in order to aid in correction of the negative energy balance and restoration of a healthy weight. With early identification, these athletes can successfully return to high levels of performance while contributing to good health for the future.

With increasing numbers of girls participating in organized sports at high levels, anyone involved in the care and development of these athletes must be vigilant for features of the female athlete triad. Preparticipation screenings are designed to include questions that may assist in the recognition of the female athlete triad. Warning signs include an athlete's obsessive control of their eating behaviors, rapid and progressive weight loss, fundamental change in monthly menstrual patterns with either irregularity or loss of normal menstrual periods, and repeated stress fractures. These features should always prompt an evaluation by the team physician or personal primary care physician.

Management of female athlete triad associated with unintentionally poor nutritional status (disordered eating) is primarily the role of the sports nutritionist with support from a physician. Correction of the inadequate calorie consumption generally resolves the triad completely. If a frank eating disorder is present, a team of treating specialists including a psychiatrist/psychologist, team/primary care physician, and sports nutritionist is essential for adequate management. Athletic participation often must be limited in order to aid in correction of the negative energy balance and restoration of a healthy weight. With early identification, these athletes can successfully return to high levels of performance while contributing to good health for the future.