title: Onset of puberty, menstrual frequency, and body fat in elite rhythmic gymnasts compared with normal controls.
abstract: OBJECTIVE
  To assess the prevalence of delayed menarche and abnormal menstrual patterns, as well as the association of menstrual status with physical training in elite rhythmic gymnasts from Greece and Canada.
  
  
  METHODS
  Fifteen Greek (mean (SEM) age 14.5 (0.2) years) and 30 Canadian (mean (SEM) age 14.7 (0.4) years) rhythmic gymnasts were surveyed for age at menarche, menstrual frequency, and training profile, and measured for height, weight, and percentage body fat (%BF). Seventy eight healthy adolescents served as country specific non-active controls: 38 Greek non-athletes (mean (SEM) age 14.5 (0.1) years) and 40 Canadian non-athletes (mean (SEM) 14.2 (0.1) years).
  
  
  RESULTS
  Of the Greek gymnasts, 79% had not yet menstruated compared with 34% of the Canadian gymnasts. Menarche was significantly (p<0.01) delayed in the rhythmic gymnasts (composite mean 13.8 (0.3) years, n = 45) compared with the controls (composite mean 12.5 (0.1) years, n = 78). There was no significant difference between Greek and Canadian gymnasts for the age at menarche (14.2 (0.3) v 13.6 (1.2) years respectively). Menstrual irregularities were reported in 78% (61% oligomenorrhoeic and 17% amenorrhoeic) of the menarcheal athletes. Menarcheal gymnasts were found to be significantly (p<0.05) taller and heavier, with a higher %BF and a lower training frequency and training duration (p<0.05) than the premenarcheal gymnasts. Overall, the mean %BF of the gymnasts was significantly lower (p<0.05) than that of the control subjects. The Canadian controls exhibited a significantly (p<0.05) greater %BF than the Greek controls of the same age.
  
  
  CONCLUSIONS
  Delayed menarche, menstrual irregularities, and low body fat are common in elite rhythmic gymnasts. Premenarcheal gymnasts train more often and for longer, and have a lower body mass index and less body fat, than menarcheal gymnasts. Prospective studies are needed to explore further these and other factors associated with delayed menarche and menstrual irregularities in female athletes.
authors.affiliation: Faculty of Applied Health Sciences, Brock University, St-Catharines, Ontario, Canada. nota.klentrou@brocku.ca
authors.forename: P
authors.initials: P
authors.lastname: Klentrou
authors.forename: M
authors.initials: M
authors.lastname: Plyley
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000568:Amenorrhea / Q000503:physiopathology; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D002170:Canada; D016022:Case-Control Studies; D005260:Female; D006115:Greece; D006173:Gymnastics / Q000502:physiology*; D006801:Humans; D008572:Menarche; D008599:Menstruation Disturbances / Q000503:physiopathology*; D009839:Oligomenorrhea / Q000503:physiopathology