The purpose of present study was to examine how the bone mineral density (BMD) of lumbar vertebrae and femoral neck was related to the age, physical constitution, muscle strength, blood component, caloric and alcoholic intake, also the variation of BMD, muscle strength and the another through exercises. The healthy adults of both sex participated in this study.
　The results were summarized as follows :
　1) It was in men's lumbar vertebrae where the most significant correlation of BMD to other factors was recognized.
　2) It was recognized there was a marked tendency to the fact that the physical constitution of men as well as the blood component of women had the higher relative rate of contribution to each BMD.
　3) It was recognized there was much less correlation in the study of BMD to blood component, caloric and alcoholic intake compared to that with age, physical constitution and muscle strength, however in the case of women the study suggested some importance in the relativity of BMD to the earlier listed factors combined.
　4) It was in the men's lumbar vertebrae where the contribution rate of the other factors to BMD was the highest. It was also considered that in the study of men's lumbar vertebrae the height, ratio of fat, knee extensor strength and back strength held more significance as the factors contributed practically in physical measurement.
　5) It was recorded that the annual variation rate was lower in BMD than in muscle strength. It was also recognized that the relativity among the annual variation rates showed significantly positive correlation of the women's body weight (age between 20 and 39) and their knee flexor strength to BMD of lumbar vertebrae, while significantly negative correlation of their knee extensor strength to BMD of lumbar vertebrae.
　6) It was recognized there was a tendency for the BMD in lumbar vertebrae to stay the same or even become increased through exercises, however it was supposed the effect would be much less in comparison with the cases of cardio-respiratory function and knee muscle strength. The relation between the variation rates of BMD and those of muscle strength and the another through execises was still uncertain. Although marked increase in both BMD was observed in man who included bounding exercise and it was suggested that this type of exercise was effective to increase BMD, more careful investigation had to follow to determine its appropriateness.

DESCENTE SPORTS SCIENCE Vol.14/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE