Promoting physical activity using a wearable activity tracker in college students: A cluster randomized controlled trial.

This study examined the effects of utilizing a wearable activity tracker in a credit-based physical activity instructional program (PAIP) for promoting physical activity (PA) in college students. Fourteen PAIP courses in a large public university were randomly assigned into intervention (k = 7; n = 101) and control (k = 7; n = 86) groups. All courses focused on a core curriculum that covers basic exercise and behavioral science contents through lectures and activity sessions. A Misfit Flash activity tracker was provided to students in the intervention group. Objective PA assessments occurred at baseline, mid-, and end-of-semester during a 15-week academic semester. The control group showed a significant reduction in moderate- and vigorous-intensity PA (MVPA) minutes from baseline to the end-of-semester (P <.05), whereas the intervention group showed no changes in MVPA minutes over time. However, the intervention group also showed increased sedentary time and decreased time spent in light-intensity PA during the intervention period. Taken together, the present study found null effects of utilizing the wearable activity tracker in promoting PA in college students suggesting that intervention of primary using the wearable activity tracker as a behavior change strategy may not be effective to increase in PA in this setting.

Physical Activity, Screen-Based Sedentary Behavior, and Sleep Duration in Adolescents: Youth Risk Behavior Survey, 2011-2013.

This study examined the concurrent associations of physical activity and screen-based sedentary behavior with sleep duration among adolescents by using data from the national Youth Risk Behavior Survey 2011-2013. Using latent class analysis, we identified 4 latent subgroups of adolescents with various levels of physical activity and screen-based sedentary behavior. The subgroup with high levels of physical activity and low levels of sedentary behavior generally showed greater odds of having sufficient sleep (≥8 hours/night) than the other subgroups. Findings imply that concurrent achievement of a high level of physical activity and low level of screen-based sedentary behavior is necessary to promote sufficient sleep among adolescents.