Adding web-based support to exercise referral schemes improves symptoms of depression in people with elevated depressive symptoms: A secondary analysis of the e-coachER randomised controlled trial

•We report the effects of augmenting exercise referral schemes with web-based support for people with elevated depressive symptoms.•We investigated whether changes in outcomes were mediated by changes in physical activity and psychological processes.•Those randomised to e-coachER reported improved symptoms of depression compared with controls at four months.•Intervention effects on confidence, competence and self-monitoring at four months mediated reduction in depression scores.•Intervention effects on competence and self-monitoring at four months mediated improvements in anxiety scores at four months.