The purpose of this study was to clarify the exercise intervals to augment blood flow to exercising region and to determine the effect of dynamic plantar flexion exercise training on dilation capacity of blood vessel during exercise. Based upon the time to reach peak blood flow after contraction, the exercise intervals were set up Eighteen healthy female subjects performed dynamic plantar flexion exercise. Blood velocity signal and vessel diameter of the popliteal artery were measured using ultrasound Doppler method and ultrasound B-mode method. In experiment A, the time from immediately after single contraction to peak blood flow was determined. Three different exercise intervals were set up at 10, 30 and 50% of the time to peak blood flow, respectively. No difference in blood flow was made among three exercise intervals. In experiment B, 2 times of exercise training were performed 4 times a week for 3weeks; one consisted of exercise with the interval at 20% of the time to peak blood flow (TA) group and the other at 100% (TB) group. Peak blood flow after exercise tended to increase after training in both groups. However, the rate of blood flow increase in TA group was significantly (p<0.05) higher than that in TB group. The results suggest that the dilation capacity of blood vessel during exercise increased by training using exercise intervals set up at time before reaching peak blood flow.

DESCENTE SPORTS SCIENCE Vol.26/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE