Perceived control predicts lower end-of-day stress through engagement in moderate or vigorous physical activity: A daily diary study in a US adult sample.

Perceived control (PC) is associated with lower perceived stress, but the mechanisms of this relationship have not yet been established. The current study examined whether moderate or vigorous intensity physical activity (MVPA) mediated the relationship between PC and daily stress in a sample of US adults. Participants (N = 264, M_age = 34.08, 61.4% female) completed a baseline measure of two dimensions of PC (i.e., mastery and constraints), followed by 11 days of daily surveys that assessed daily MVPA and perceived stress. We employed linear mixed effects modelling to estimate the within-and between-person indirect effects (IE) of MVPA on the relationships between each dimension of PC and daily perceived stress. Greater PC (i.e., higher mastery and lower constraints) was associated with a higher frequency of MVPA engagement, and participants reported lower levels of end-of-day perceived stress on the days in which they had engaged in MVPA. We observed within-person mediating effects of MVPA on the relationship between both PC dimensions and daily stress (mastery: within-person IE = -0.03, 95% CI: [-0.06, -0.01]; constraints: within-person IE = 0.03, 95% CI: [0.01, 0.06]). These findings suggest that MVPA is a potential mechanism through which US adults with greater PC experience reduced levels of daily stress. The current study illuminates a key pathway for the stress-reducing impact of PC to inform future research and interventions targeting stress and its associated sequelae.