The purpose of this study was to investigate the influence of lack of calcium intake and physical training on skeletal muscle growth.
　Fourty male Wistar rats were classified into normal diet control (NDC), low calcium diet control (LCDC), nomal diet training (NTD) and low calcium diet training (LCDT) group at 3 weeks of age. Low calcium diet groups were given one-fifth calcium concentration of normal diet. Trained animals were run on a treadmill for 60 min per day at 25 m per min for 6 days per week for 8 weeks. The effects on the muscle growth of calcium intake limitation were assessed in term of bone weigth, contractile properties and enzyme activities of soleus and extensor digitrum longus muscles. There were decrease in femoris and Tibiae weight by about 50% in low calcium diet groups. Body weight and muscle weights of LCDT group gained less than other groups. Contraction time increase in low calcium diet groups.
　Maximum tetanic tension decrease in low calcium groups. There were no significant differences in phosphfructokinase activity between the groups. In soleus muscle statistically significant decrease were found for succinate dehydrogenase activities in low calcium diet groups. A similar tendency was indicated in extensor digitrum longus muscle, but it was not significant. Training did not suppress the these results. It is assumed that the effects of calcium lack on skeletal muscle are almost the same as dystrophy muscle which is deteriorated by high concentration of calcium. And these results suggest that the lack of calium intake affect the normal muscle developing.

DESCENTE SPORTS SCIENCE Vol.12/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE