Absence or cessation of menstrual periods is not a normal response to exercise in adolescent athletes and should lead to a complete medical evaluation: that is a key recommendation of the American Academy of Pediatrics' Committee on Sports Medicine and Fitness, which has issued new guidelines to pediatricians on monitoring the health of young female athletes. The recommendations are equally relevant to British coaches, parents, health professionals - and anyone concerned with ensuring that youngsters' health and normal maturation is not compromised by performance requirements.

In a paper published in Pediatrics, the committee identifies three key concerns:

• Disordered eating, which may be unintentional (when energy supply does not keep pace with expenditure) or deliberate (a conscious attempt to lose weight or body fat to improve appearance or athletic performance).
Sports that may place athletes at higher risk for the development of eating disorders include those in which leanness is emphasised (eg gymnastics, ballet dancing, diving and figure skating) or perceived to optimise performance (eg long distance running) and those which use weight classification (eg martial arts and rowing).
In fact disordered eating - including bingeing and purging, as well as food restriction -may impair athletic performance and increase the risk of injury as well as causing dangerous medical and psychological complications;

• Menstrual dysfunction, which can be caused by disordered eating, and is more common in athletes than the general population. This in turn may lead to...

Decreased bone mineral density (BMD), leading to premature osteoporosis. According to the committee, girls who start menstruating at a later age, and have a lower weight during adolescence than their peers, have been found to have the lowest BMD.

"The physical examination that precedes participation in sports is an ideal opportunity to screen for problems of disordered eating, menstrual dysfunction and decreased BMD" say the authors. "Signs of disordered eating may be recognised by parents, coaches, athletic trainers, teammate or school nurses and brought to the physician's attention." After that, further evaluation, with input from a nutritionist and a mental health professional, may be necessary. Increased dietary intake or decreased energy expenditure usually results in the development or resumption of menstruation, resulting in turn in increased BMD although some bone loss may be irreversible.
Other recommendations are as follows:

• Dietary practices, exercise intensity, duration and frequency and menstrual history need to be reviewed during medical evaluations of young athletes;

• Disordered eating should be suspected in adolescents with amenorrhoea and may require treatment by a multi-disciplinary team of health professionals;

• Athletes, parents and coaches should be counselled on the perils of disordered eating, menstrual dysfunction and bone loss and educated on the constituents of a healthy diet;

• When athletes and coaches seek details of the recommended weight and percentage body fat, it is best to offer a range of values. It is difficult and potentially dangerous to define an ideal level of weight and/or body fat for each sport or individual participant. Weight is not an accurate estimate of fitness or fatness, and when weight is lost, muscle and fat are lost;

• An adolescent with menstrual dysfunction attributable to exercise should be encouraged to increase her energy intake and modify excessive activity. If her weight is low she may need to gain weight before resuming athletic activity.

Norman Matthews
England Junior Coach