A group-based prevention program fostering mental health and physical activity: Pre- to post-program outcomes and session-level measures

Objective: Physical activity (PA) and psychoeducational sessions (PsycEd) represent popular and effective components of well-being-oriented prevention programs. However, while program-level (distal) improvements are well-documented, less is known about session-level (proximal) processes and their relation to overall program effects. Methods: We investigated an 8-week, naturalistic, non-controlled, health-insurance-provided group-based prevention program comprising weekly outdoor PA and PsycEd in individuals often experiencing low mood, energy levels, tiredness, or irritability. As proximal outcomes, 80 participants reported their current mood and stress (time pressure and burden) before and after session times. They further rated each session on social support, group atmosphere, and helpfulness. Engagement was operationalized as session attendance. Changes in affective well-being (WHO-5) were assessed as the program-level, distal effect. Its moderation by session-level measures were analysed. Results: WHO-5 scores improved significantly from pre- to post-program (d=.25). Significant proximal improvements in mood (d>.60) and stress burden (d>.20) were found for PsyEd and PA. Only PA sessions were significantly linked with time pressure reductions (d=.17), while those sessions were also rated higher on social support (d=.65), group atmosphere (d=.49), and helpfulness (d=0.32). There was no significant difference between session types in attendance. Participants attending more sessions had higher WHO-5 improvements (β=.18), but no other session-level variable significantly moderated this improvement. Conclusion: While the study’s limitations of the missing control group, the potential mismatch between distal and proximal measures, and the mostly female sample should be considered, potential program effectiveness might be boosted by targeting continued attendance. Outdoor PA might be slightly superior to PsycEd in activating group benefits and could potentially be expanded.