The purpose of this report is to study the effect of menstrual cycle on muscular functions. The subjects were five female students with a history of regular menstrual cycles. The isometric maximum strength the force-velocity relations, and the number of contraction (muscular endurance) with load of 1/3 maximum strength of each subjects, of the elbow extension and flexion were determined during the follicular and luteal phases of their cycle.
　The following results were obtained;
　1) The isometric maximum strength of the elbow extension and flexion did not change follicular and luteal phases.
　2) The velocity of the elbow extension under without load condition, the follicular phase was significantly faster than luteal phase.
　3) The number of contraction of the elbow flexion was higher in luteal phase than in follicular phase, and the muscular endurance of the elbow extension was higher in difference were not significant.
　These studies suggest that the menstrual cycle influences muscular function.

DESCENTE SPORTS SCIENCE Vol.9/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE