Japan has been experiencing an aging of its society, with elderly people thus being required to have abilities that allow them to live independently. Therefore, it is important for them to sustain their existing physical functions for as long as possible. The present study aimed to elucidate the characteristics of physical functions involved in the daily activities of elderly people. The authors measured the volume of activity undertaken by elderly women in order to investigate how they spend their daily lives and how much energy they utilize on daily activities. The subjects were 50 elderly and 30 middle-aged healthy women. A covariance structure analysis shows that the total volume of their activities are closely related to their household and outdoor activities while, on the other hand, the total volume of activity is only indirectly affected by their age. And the elderly spend more time indoor than outdoor. This demonstrates that the household work activities are major factors for the maintenance and improvement of health.