抄録
Training effect of muscular endurance has been studied with respect to muscle oxygen intake from blood flow and oxygen content in blood. Oxygen of blood was analyzed by Van Slyke apparatus. Blood flow of the forearm was measured by Whitneys' gauge. Ultrasonic apparatus was applied to know the amount of the muscle tissues. Five male subjects engaged in a training program once a day for l2 weeks. Training exercise was made by the rhythmic grip contractions (60 contractions/min.) against the weight of 1/3 of maximum strength. This exercise continued up to exhaustion on the hand-ergometer. The measurements were made 5 times through the training period; before training, 3rd, 6th, 9th week as well as at the end of training period. The number of contractions up to exhaustion increased remarkably from 82.2 to 267.4 at the end of training in the mean. Muscle oxygen intake and blood flow resulted in significant increase from 3.88 to 6.28 (ml./100ml. muscle/min.) (p<0.01), and from 32.27 to 49.54 (ml./100ml.forearm/min.) (p<0.05) respectively. It was found that improvement in muscular endurance was associated with increase of muscle oxygen intake. Furthermore, the increase in muscle oxygen intake was more closely related to the increase of blood flow than that of arteriovenous oxygen difference. Oxygen intake per unit mechanical work decreased markedly (from 0.91 to 0.56 ml./kgm), indicating improvement of the mechanical efficiency
