This study concerns the effects on electromyogram (EMG), heart rate (HR), blood flow in abdominal aorta (BF) and perceived sense of compression during the compression of both thighs. The subjects were eight healthy males and thirty-four healthy males. The group of eight healthy males were requested to pedal in a supine position using a bicycle ergometer. The compression at 10 mmHg, 20 mmHg and 40 mmHg in both thighs was obtained by application of a manchette for the thighs.
　The results obtained, as compared with the control conditions (no pressure), were as follows ;
　1) Integrated EMGs (IEMGs) of m. adductor magnus, m. semi-membranosus and m. semitendinosus for hip extension significantly increased at a pressure of 40 mmHg. IEMG of m. vastus lateralis for knee extension significantly decreased at pressures of 10 mmHg and 20 mmHg.
　2) HR showed increase at a pressure of 40 mmHg.
　3) BF was increased sharply at the beginning of exercise at a pres-sure of 10 mmHg, at the middle of exercise at a pressure of 20 mmHg, and at the end of exercise at a pressure of 40 mmHg.
　A perceived sense of compression was felt to make a difference somewhere between an absolute pressure and a conscious pressure. A conscious pressure was felt to be lower than an absolute pressure.
　These results suggest that a compression range of between 10 mmHg and 20 mmHg in both thighs may have a favorable effect on the performance of the exercise over an extended period.

DESCENTE SPORTS SCIENCE Vol.17/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE