Reconsideration of exercise prescription as the countermeasure for prevention of muscle atrophy in space

Abstract

Responses of electromyogram (EMG) activities in soleus and vastus lateralis (VL) to various types of exercise were examined in human subjects. The soleus EMG activity during walking was gradually increased in subject whose heel lands on the treadmill first, when the speed and uphill inclination were increased. But in some subjects whose front sole lands first, soleus was more active when they were walking slowly on a flat treadmill. Greater EMG activities of soleus, but not VL, were observed during pedaling or lifting weight on the floor by using their front sole, vs. arch or whole sole, in all subjects. Utilization of VL, in which EMG level was greater during cycling than walking, was stimulated, when the load of bicycle ergometer was increased. It was suggested that muscle specific exercise should be performed as the countermeasure. This study was supported, in part, by Grant‐in‐Aid for Scientific Research S (19100009, YO) from Japan Society for the Promotion of Science.