RÉSUMÉ
The effect of isokinetic training was investigated for the strength development in the thigh muscles under various training conditions. Thirty one males from healthy high-school students served as subjects of this study. Training was performed using a Cybex II machine with two kinds of repeated load conditions (number of repetitions, cf. Table 1 & Fig. 1) at to different rotational speeds (30 degrees and 180 degrees per second) . The training was done three times per week for nine weeks. The effects of training were evaluated on the basis of the amount of increase in the strength during knee flexion and extension.<BR>The results were summarized as follows :<BR>1) The effect of training became apparent most swiftly under the rotational speed of 180 degrees per second and light load of repetitions, respectively.<BR>2) The largest increase in the muscluar strength was observed for the group with training speed of 180 degrees per second and hevey load of repetitions, respectively.<BR>3) The strength increased periodically every four or five week for all conditions.