Within-person associations between daily stress and physical activity during working and non-working hours.

People experience stressors on 40% of days, and emotional responses to stressors increase the risk for poor health, in part by impacting health behaviors like physical activity (PA). However, whether associations of daily psychological stressors with PA after the self-reported stressor occurs (post-stressor PA) differ across working and non-working hours is unclear. This study used the National Study of Daily Experiences III (2017-2019) to examine within-person associations between stressors and post-stressor PA during working and non-working hours and moderation by age and biological sex. Participants completed interviews across eight consecutive days about daily stress and the amount and timing of PA participation during the past 24 hours. Multilevel models with days nested in people examined the within-person associations of stressors with the odds and amount of post-stressor PA participation, with separate models during versus outside of working hours on working days and for non-working days. Participants (N = 564) had higher odds of post-stressor PA during working hours when they experienced greater than usual anger (OR = 3.24, p < .001), sadness (OR = 2.41, p < .001), or shame (ORs = 2.59, p < .001) due to stress. Sex moderated the within-person associations between stressor frequency (OR = 0.29, p < .001), intensity (OR = 0.49, p < .001), and anxiety (OR = 0.58, p = .002) on odds of post-stressor PA during working hours, such that the increased odds were higher in males. Participants had higher odds of post-stressor PA outside of working hours when they experienced greater stress intensity, anger, sadness, shame, or anxiety (OR = 3.94-7.35, p < .001). Research clarifying how age, sex, and/or occupation intersect with individuals' daily stress experiences and PA could inform occupational health policies and/or interventions.