We have measured bone mineral density (BMD) of lumber spine (L2−L4) and proximal femur (neck, Ward's triangle, trochanter) in 360 healthy female students aged 18 - 24, and studied their athletic activity and other lifestyles from childhood to the present. BMD of the students were correlated to their body weight, body mass index (kg/m²), muscle strength (grip and back strength), duration of athletic activities and age of menarche. There was no significant difference between their average BMD and the peak bone mass when we compared to the BMD data of 727 subjects aged from 12 to 74.
　The data showed that more 3 years' athletic history significantly increased BMD of femur neck, and more than 6 years history increased BMD of L2-L4.
　Especially, the athletic history from 13 to 15 years old has more potent effect on BMD of neck than the history from 16 to 18 years old. However, no difference was found between BMD of neck in the student with athletic history from 13 to 15 years and the BMD in the students with the history from 13 to the present.
　Among various items of sports, volleyball had the most potent effect on BMD than the other sports. When BMD was adjusted by different body weight due to the various sports items, BMD of volleyball, track and field and basketball players was significantly higher than that of non-player.
　These data suggested that athletic history for 3 years at age 13 to 15 should be extremely important and that such sports items as volleyball, track and field and basketball be more effective in increasing peak bone mass and in preventing osteoporosis.

DESCENTE SPORTS SCIENCE Vol.16/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE