Age at menarche in athletes and their mothers and sisters.

Retrospective ages at menarche were obtained from 109 university athletes and their mothers, and from 77 sisters of the athletes. The athletes were participants in seven sports. Mean age (+/- SD) at menarche of the 109 athletes was identical with that of the total sample of 338 athletes from which they were drawn, 13.8 +/- 1.5 years. Mean age at menarche in the mothers was 13.4 +/- 1.7 years. When mothers were grouped as having been athletes (n = 52) or non-athletes (n = 57), menarcheal ages were, respectively, 13.7 +/- 1.8 years and 13.2 +/- 1.5 years. The mother-daughter correlation for age at menarche was 0.25. Corresponding correlations between athletes and mothers who were athletes and between athletes and mothers who were not athletes were 0.24 and 0.22, respectively. Ages at menarche in athletes who had sisters (n = 62) and their sisters (n = 77) were 14.0 +/- 1.4 and 13.6 +/- 1.6 years, respectively. The intraclass sister-sister correlation was 0.44. Familial resemblance in age at menarche in athletes, their mothers and sisters, is identical with that in the general population, and suggests that later menarche commonly observed in athletes is to a large extent familial.