Correlation between daytime activities and night sleep of aged individuals estimated by wrist activity and sleep log

The daytime and night-time activities in 15 aged subjects was studied using a wrist-worn activity device. A significant negative correlation between the amount of daytime and night-time activities was found (gamma=0.26, P < 0.01). There was a significant gender difference relating to the amount of daytime activity; women had significantly greater amount of daytime activity than did the men (P < 0.001). These results suggest that aged people with higher daytime activity sleep better than those with lower daytime activity and that nocturnal sleep in women may be less disturbed.