Associations Between Smartphone Screen Time, Sedentary Behavior, and Physical Activity in Young Adults
Restricted (Penn State Only)
Area of Honors:
Bachelor of Science
David E Conroy, Thesis Supervisor Lacy Marie Alexander, Honors Advisor
smartphones physical activity sedentary behavior screen time
Screen time has been inconsistently associated with adverse health outcomes such as obesity and depression. The mechanism of this link is not well understood, but it is possible that screen time impacts overall health by altering movement- and non-movement-related behaviors such as sedentary behavior and physical activity. Smartphone screen time is of particular interest because smartphones are universal and portable. The purpose of this study was to determine the associations between total smartphone screen time and sedentary behavior and physical activity. A secondary purpose was to investigate the relationship between frequency of smartphone use and these two behaviors. During a 9-day ambulatory monitoring period, smartphone use was measured using Apple’s Screen Time software and activity was measured using a wearable device. Increased total screen time was significantly associated with increased sitting time and decreased step count at the within-person level of analysis. More frequent interactions with the smartphone (pickups) were positively associated with step count at the between-person level and sedentary behavior at the within-person level. This evidence suggests that smartphone screen time has the potential to influence health outcomes by altering physical activity and sedentary behavior.