It is not well established as to whether the nocturnal sleep would be affected by the preceding exercise in daytime. While the exercise is known to elicit acutely a reduction in blood pressure (BP) for approximately 1-2 hours (i.e. post-exercise hypotension: PEH) even in healthy subjects, it is still unclear as to whether the PEH would be lasting for more duration. We, therefore, determined the effect of aerobic exercise in early evening on the quality/quantity of sleep and its hemodynamic response in the following night. Ten healthy young male subjects (age: 18-25 yr) participated in two protocols either with or without cycle ergometer exercise (60 min at 50% HR reserve) in early evening. The ambulatory monitoring of BP/HR and physical activity by accelerometer were performed from the late afternoon (i.e. 30 min before exercise) to the noon of next day. In addition, the watch-typed device for identifying the stage of sleep based on the heart rate variability analysis was equipped during the bedtime. There were no substantial differences in the sleep indices between with and without a preceding exercise. The mean value of BP during nocturnal sleep showed a tendency to be lowered by the preceding exercise (P=0.08)．The aerobic exercise in early evening has no acute effect to the sleep itself, but some residual effect to the hemodynamic response during sleep, i.e. the prolonged PEH.

DESCENTE SPORTS SCIENCE Vol.32/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE