Monma T, et al. - In this ecological study in all prefectures in Japan, researchers assessed healthy life expectancy in correlation with engagement in exercise or sports among middle-aged persons. They used data from the 2005–2010 Longitudinal Survey of Middle-aged and Elderly Persons by the Ministry of Health, Labour and Welfare of Japan. They found longer healthy life expectancies in prefectures with a higher ratio of middle-aged people engaging in exercise or sports, particularly when done with families or friends. Especially males exhibited this finding. As far as improving healthy life expectancy was concerned, males can benefit more compared with females in Japan from engaging in exercise or sports with families or friends in midlife.