Exercise is known to confer longevity benefits, but whether energy expenditure through any activity offers similar benefit is not known. Manini and colleaguesArticle measured total energy expenditure, resting metabolic rate, and thermic effect of food in 302 high-functioning community-dwelling older adults (ages 70-82 years at baseline). From these measures, they calculated free-living activity energy expenditure of each participant. During a mean 6 years of follow-up, the authors found that higher free-living activity energy expenditure was associated with lower mortality risk in the study participants. In an editorial, Blair and HaskellArticle discuss the contributions of physical activity and nonexercise activity thermogenesis to daily energy expenditure and the need for objective measurements of the amount and intensity of physical activity.