To clarify possible affection of respiratory entrainment to hyperpnea during moderate exercise, bicycle exercises with three different pedalling rates (35, 60, 80 rpm) with equal oxygen consumption were conducted.
　Twelve normal subjects (one man and 11 women) were studied the ventilatory responses during moderate exercises in room air breathing or progressive isocapnic hypoxia.
　The results were as follows:
　1) Respiratory frequency during exercises (60, 80 rpm) in six subjects was higher than of 30 rpm exercise in room air breathing. Accordingly, respiratory responses of these six subjects (entrainment group) were compared with that of the other six subjects (non-entrainment group).
　2) Minute ventilation in room air breathing in the entrainment group was also larger than that of the non-entrainment group during exercises (60, 80 rpm). At 80 rpm exercise, significant difference was seen between two groups.
　3) Significant difference between two groups was still found in respiratory frequency in hypoxia (at PETO₂ 50 mmHg) during 80 rpm exercise.
　4) It is suggested that respiratory entrainment is likely to affect the ventilatory response during exercise and rate of rhythmic movement during exercise must be considered in the studies of exercise hyperpnea.

DESCENTE SPORTS SCIENCE Vol.7/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE