Daily self-efficacy, planning and social support explain leisure-time physical activity in working adults: evidence...

Identifying theory-based, modifiable processes and resources in everyday life is essential for improving physical activity levels, and leisure-time physical activity (LTPA) especially. Deconfounding different sources of social support for day-to-day LTPA, we examined effects of LTPA-specific received support from both private and work domains. Furthermore, we investigated whether daily intrapersonal processes - such as positive affect, self-efficacy, and planning - are linked with LTPA through cultivating social support.

A total of 118 adults (M _age = 37.88, SD = 11.73, 65% women) participated in a 15-day ambulatory assessment study. Morning positive affect, self-efficacy, and planning, afternoon LTPA-specific received social support from family/friends, and colleagues/supervisors, and self-reported LTPA and working hours (both measured in the evening) were assessed daily. LTPA was also measured using accelerometers combined with worktime information. First, we fit multilevel models to explain device-assessed and self-reported LTPA. Second, within-person mediation analyses examined the role of received social support as a potential mediator between relevant intrapersonal processes and LTPA at the day level.

On average, participants received more LTPA-specific support from the private compared to the work domain. Having received higher-than-usual social support from family/friends on a day was consistently linked to higher LTPA. No such within-person effect emerged for support from colleagues/supervisors. On days with higher-than-usual self-efficacy and planning, participants performed more LTPA, whereas positive affect was unrelated to LTPA at the within-person level. These results were found for both device-assessed and self-reported LTPA. Within-person mediation analyses revealed that between 16%-22% of the effects from self-efficacy and planning to device-assessed/self-reported LTPA were mediated by social support from family/friends.

Our results identify intrapersonal and private-domain social exchange processes as potential targets for future ecological momentary interventions. Consistent with the cultivation hypothesis, we also identified that daily self-efficacy and planning were linked to LTPA via social support from family/friends.