Combining diaries with accelerometers to understand within- and between-person links between support and activity

Abstract

Background: Social support has been found to be a correlate of physical activity in cross-sectional studies, but the support-activity link has rarely been studied in daily experience studies. This intensive longitudinal study examined the link between daily social support and physical activity both between and within participants. Methods: Participants (N = 68) wore accelerometers to capture daily activity and reported the amount of exercise-related social support in an online evening diary for 6 consecutive days. Findings: Participants who received more social support on average and on a given day were more physically active. Individuals with higher levels of social support showed more physical activity on average (between-person support-activity link, b = 858 daily steps, p = .02). Within participants, on days when participants received more social support than usual they were more physically active (within-person support-activity link, b = 652 daily steps, p = .01). Discussion: Social support and activity showed day-to-day fluctuations and evidence for a between-person and a within-person link, underscoring the importance of studying social processes and health behaviors in daily life.