- 体育學研究 (ISSN:04846710)
- vol.48, no.5, pp.523-539, 2003-09-10
The hypothesis that menarche is delayed in female athletes has not been verified, despite many studies widely eported in the US and a few investigations conducted in Japan. The purpose of the present study was to examine statistically whether regular sports training for female athletes in childhood delays the age at menarche. Health examination records and history of exercise were investigated for 144 female high school senior athletes in the Tokai area, who had participated in competitions at the national level. The investigations covered the period from the first grade of elementary school until the final year of high school (from 1985-1987 to 1996-1998). The sports played by the subjects included track and field (n=21), basketball (n=15), volleyball (n=21), softball (n=7), tennis (n=16), soft tennis (n=25), hockey (n=8), judo (n=19), table tennis (n=6), handball (n=3) and swimming (n=3). Longitudinal data for height and weight were obtained from health examination records. Age at menarche was obtained by questionnaire (from recollection). The control group comprised 78 female non-athletes investigated in a similar manner to the athlete group. Delay in menarche was judged from the interval between menarche and physical maturation level. Ages at maximum peak velocity (MPV) of height in the athletes and control groups were derived using the wavelet interpolation method (WIM) as the criterion for maturation level. The interval between age at menarche and age at MPV of height was then derived for each group. The difference in the derived age interval between the two groups was tested for significance (t test) to compare the athletes and the controls. In addition, age at menarche and age at MPV of height were compared between the groups. The results were then used to determine whether menarche in female athletes was delayed. It was found that the age at menarche was significantly later in athletes (12.82 ± 1.15 years) than in the control group (12.11 ± 0.90 years), with the exception of table tennis players (P<0.01). However, age at MPV of height did not differ significantly between the groups, except for tennis players. A significant difference in the age interval between MPV of height and menarche was observed between the control group (1.08 ± 0.74 years) and the athlete groups (1.75 ± 1.23 years), with the exception of tennis and table tennis players (P<0.01). It may be concluded from these results that regular sports training for female athletes in childhood delays the age at menarche.