Effects of daytime activity on nocturnal sleep in the elderly.

This study investigates the relationship between the level of daytime activities and nocturnal sleep in the elderly using the wrist actigraph and ambulatory polysomnograph system. Five male and five female subjects (mean age = 73.8+/-3.05 years; range 69-77 years) participated in this study. The level of daytime activity was positively correlated with the sleep efficiency of the subsequent night only for male subjects, who were shown to be less active during the daytime. The results imply that increments in the time spent on physical activities may improve the quality of nocturnal sleep in elderly male subjects.