EFFECTS OF ENDURANCE TRAINING ON HISTOCHEMICAL PROPERTIES OF RAT SKELETAL MUSCLE / 体力科学

ABSTRACT

Wistar rats (30 days after birth) were trained by treadmill running for fifteen weeks. The training program consisted of endurance running at a speed of 30 meters per minute, for 30 minutes a day, and 5 days a week. After the training, fiber composition and fiber area of thier leg muscles were histochemically studied.<BR>Samples of the soleus, EDL, and plantaris muscles were stained with succinate dehydrogenase (SDH) and myosin ATPase, and the muscle fibers were classified into the three types : fast-twitch glycolytic (FG), fast-twitch oxydative glycolytic (FOG), and slow-twitch oxydative (SO) .<BR>The body and muscle weights of the rats in the training group were larger than those of the control group, but the difference was not significant.<BR>After the training, the ratio among the numbers of three fiber types showed no difference between the training and control groups. Also, the average cross-sectional areas of the FG fibers showed no difference between the training and control groups ; however, those of the FOG and SO fibers were 8-11% larger in the training group than in the control group.<BR>These results obtained in the present experiments indicated that the trained rats increased in their fatigue resistivity through the training.