Investigating the relationships between job characteristics, physical activity, and well-being : a mixed methods approach

Abstract

This dissertation is devoted to a detailed evaluation of the relationships between job characteristics, leisure-time physical activity (LTPA), and well-being drawing on the assumptions of the recently introduced physical-activity mediated Demand-Control (pamDC) model by Häusser and Mojzisch (2017). The two key concerns were to i) evaluate the effects of job demands (via self-regulation) and job control (via self-determina-tion) on LTPA within varying time frames (ranging from short-term effects within days to time-lagged effects over weeks), and ii) test for a mediating effect of LTPA for the effects of job demands and job control on well-being for the first time.To address these questions, five empirical studies were conducted that differ in their scope (Study 1 aimed to test the central assumptions of the pamDC model for the first time, whereas Studies 2 to 5 focused on the relationships between job characteristics and LTPA) and methodological approach. While Studies 1 and 5 were based on longitudinal designs with a working sample, Studies 2 to 4 employed experimental designs to increase confidence with regard to causal directions of the assumed processes.Overall, I found general support for the effects of job demands on LTPA (as three out of four studies found an effect) although this effect does not seem to be mediated through self-control and mainly unfolded in a short time frame. There was no support for direct effects of job control on LTPA as none of the studies that tested these relationships revealed significant effects. However, there was an indirect effect of job control on LTPA through self-determination in Study 4. With regard to the proposed mediation of LTPA for the effects of job characteristics on well-being, I found partial support as daily LTPA could be identified as a mediator for the effects of daily job demands but not for the effects of daily job control on well-being.