We have done the examination of bone mineral density on female college athletes (n=17), male college athletes (n=27), elderly gateballers, and middle-aged swimmers (n=39). We have gained some conclusions as follows.
　1) The bone mineral density on tibia shaft in female college swimmers was lower significantly compared with general women. The bone mineral density on lumbar vertebra and tibia shaft in female college judo participants was higher significantly compared with general women.
　2) The bone mineral density on left femoral neck in male college basketball players was higher than those in volleyball, judo and short track events athletes. The % young reference of left femoral neck in male college basketball players was significantly higher than that in short track events athletes.
　3) The bone mineral density on lumbar vertebra in elderly male gateballers (average 74.6 years, average playing time 28.4 hours/month) was decreased significantly during 11 months. But the bone mineral density on lumbar vertebra in middle-aged swimmers (average 58.3 years, average swimming time 17.0 hours/month) was increased during 9 months. The swimmers had received lectures and guidance to osteoporosis, further who had intaken more milk than the gateballers.
　Some precautions to osteoporosis were presented from these conclutions. That is, judo and basketball has good effects on bone mass increase in youth period. Further, it is important for middle-aged and elderly people to do mild exercise, intake calcium in milk and receive education about osteoporotic disease.

DESCENTE SPORTS SCIENCE Vol.22/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE