A study of élite rhythmic gymnasts in Greece and Canada has confirmed a potentially worrying prevalence of delayed and disordered menstruation compared with non-athlete controls.

Fifteen Greek rhythmic gymnasts (mean aged 14.5 years) and 30 Canadian counterparts (mean age 14.7 years) were surveyed for age at menarche (onset of menstruation), menstrual frequency and training profile and measured for height, weight and percentage body fat. They were compared across all these measures with a control group of 78 healthy Greek and Canadian non-athletes of the same age.

The differences observed were startling: whereas all girls from both control groups had achieved regular menstruation at the time of the study and none reported any menstrual irregularities, 79% of the Greek gymnasts and 34% of Canadian gymnasts had not yet menstruated. Those who were menstruating had started significantly later than the controls (13.8 compared with 12.5 years) and as many as 78% reported menstrual irregularities.

Menarcheal gymnasts were found to be significantly taller and heavier, with a higher percentage body fat and a lower training frequency and training duration than their pre-menarcheal counterparts.

These days delayed and irregular menstruation is taken seriously, not just for its potential implications for fertility but because it forms one angle of the ‘female athlete triad’ (disordered eating, menstrual dysfunction and osteoporosis), which can result in decreased performance, illness and even death.

The researchers acknowledge that undetected eating disorders might have been a ‘confounding variable’ in their study, and they have called for further research on female athletes to explore the factors associated with delayed menarche.

Br J Sports Med 2003;37:490-494