Sustaining self-regulatory efficacy and psychological outcome expectations for postnatal exercise: Effects of a group-mediated cognitive behavioural intervention

Objective. The objective of the current investigation was to examine if the effects of a group‐mediated cognitive behavioural counselling plus exercise intervention were superior to the effects of a standard exercise care condition on postnatal mothers' self‐regulatory efficacy (SRE), outcome expectations (OEs) and self‐directed physical activity (PA). Design. The design of the study consisted of two intervention conditions; group‐mediated cognitive behavioural counselling plus exercise (GMCB) and standard exercise (SE). Each condition consisted of two phases; a 4‐week supervised, centre‐based intensive exercise training phase followed by a 4‐week home‐based phase. Methods. Participants were 57 postnatal women randomly assigned to conditions (SE: N = 31; GMCB: N = 26). Measures of SRE and OEs were assessed prior to and following the centre‐based aspect of the intervention. Physical activity was measured following the intensive exercise training phase as well as the home‐based phase. Results. GMCB participants' SRE and OEs were sustained during the intervention whereas those of SE participants declined. GMCB participants also reported significantly greater time spent engaging in self‐directed PA at the conclusion of the intensive and home‐based phases. Mediation analysis revealed that SRE partially mediated the relationship between intervention condition and post home‐based PA as confirmed by a significant sobel test. Conclusions. These findings suggest that a theory‐based GMCB counselling plus exercise intervention is superior to the SE condition in sustaining SRE and OEs, and in promoting greater self‐directed PA. SRE partially mediated the relationship between intervention condition and post home‐based PA supporting the targeting of that variable for change as part of the intervention.