Examining Potential Psychosocial Mediators in a Physical Activity Intervention for Older Adults.

The purpose of this study was to examine psychosocial constructs targeted as potential mediators in a prior physical activity (PA) intervention study. This secondary analysis used data from 102 older adults randomized to one of four conditions-within a 2 (Interpersonal Strategies: yes, no) x 2 (Intrapersonal Strategies: yes, no) factorial design. We tested intervention effects on social support, self-efficacy, self-regulation, and goal attainment, and whether these constructs mediated intervention effects on PA. Participants who received interventions with interpersonal strategies, compared to those who did not, increased their readiness (post-intervention), the self-regulation subscale of self-assessment, and goal attainment (post-intervention, 6-months). Participants who received interventions with intrapersonal strategies, compared to those who did not, increased their social support from family (post-intervention). There was no statistically significant mediation. To understand mechanisms through which interventions increase older adults' PA and to improve intervention effectiveness, researchers should continue to examine potential psychosocial mediators.Clinical Trial Registry: NCT02433249.