Importance Studies have established the importance of physical activity and fitness, yet
limited data exist on the associations between objective, real-world physical activity patterns,
fitness, sleep, and cardiovascular health. Objectives To assess the feasibility of obtaining
measures of physical activity, fitness, and sleep from smartphones and to gain insights into
activity patterns associated with life satisfaction and self-reported disease. Design, Setting,
and Participants The MyHeart Counts smartphone app was made available in March 2015 …