In recent study it was found that female athletes with exercise-induced amenorrhea accompany low bone mineral density (BMD) at a high incident.
　The present study has investigated the effect of overtraining on bone metabolism and menstrual function in female elite runners.
　Subjects were 29 students of the university. There were divided into two groups according to training conditions ; 18 college athletes (Training group) ;11 physically non-active students (Control group).
　Also, the training group were divided into three groups following there kind of exercise ; the long distance group (L group), the sprinter group (S group), and the thrower group (TH groups). Calcaneal bone mass was measured by using ultrasound bone densitometer (A-1000, Lunar Co.).
　Stiffness which was calculated from both the speed of sound (SOS) and broadband ultrasound attenuation (BUA). It was used as the diagnostic criterion for measurement of bone strength.
　In addition we investigated the bone metabolism in urinary pyridinoline (Pyr) and deoxypyridinoline (D-Pyr) as a marker of bone resorption, in plasma bone alkaline phosphatase (B-ALP) and bone Glaprotein (BGP) as a marker of bone integration.
　The results obtained were as follows :
　1) The average value of stiffness for control group, L, S and TH groups were 82.1 ± 10.4, 95.8 ± 11.9, 106.5 ± 10.0 and 114.2 ± 16.0, respectively. There were significant differences against the control group.
　2) In the training group the average value of stiffness in normal menstruation group and the exercise-induced amenorrhea group were 103.1 ± 16.1 and 106.0 ± 12.73, respectively, but there were no significant differences among groups.
　3) In the training group the average value of %fat in normal menstruation group and the exercise-induced amenorrhea group were 21.9 ± 3.6 and 18.3 ± 1.9, respectively. There were significant differences between groups.
　4) In the training group the average value of bone metabolic marker and serum estradiol (E₂) in both normal menstruation group, the exercise-induced amenorrhea group showed no significant differences between groups.
　The above results suggest that calcaneal bone mass loss combined with loss of body weight, body fatness and exercise-induced decrease serum estradiol concentration.
　Although the measurement of stiffness, urinary Pyr and D-Pyr might be useful for evaluation of bone loss in athletes. The further prospective study is needed.

DESCENTE SPORTS SCIENCE Vol.19/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE