Individual versus group-based interventions: a systematic review and meta-analysis of physical activity, functional,...

Social influences, including group dynamics, social norms and peer support, are assumed to influence physical activity (PA). A previous systematic review and meta-analysis found that 'true groups' (that is, those applying group dynamics principles) had advantages over individual PA interventions. Given technological advances and virtual platforms, we updated previous findings. Systematic searches of electronic databases were completed on 19 March 2024. A meta-analysis of 71 studies (523 effect sizes) compared individual and group-based PA interventions across behavioural, functional (for example, strength and flexibility), psychosocial (for example, quality of life and loneliness) and health outcomes (for example, VO₂max). Using a three-level random effects model, group-based conditions showed a small but non-significant advantage for PA (n = 22,042; g = 0.086, 95% CI (-0.061, 0.233), P = 0.249), psychosocial outcomes (n = 18,223; g = 0.292, 95% CI (-0.171, 0.755), P = 0.214) and health outcomes (n = 31,607; g = 0.125, 95% CI (-0.023, 0.272), P = 0.096). For functional outcomes, a significant advantage for group-based interventions emerged after outlier removal (n = 14,429; g = 0.164, 95% CI (0.032, 0.297), P = 0.015). Moderation analysis indicated that different group types produced comparable effects, except that 'true groups' were associated with a larger effect size for health outcomes. Both individual and group-based approaches (in-person or online) may be effective. Future research should explore mechanisms that enhance their impact across populations and settings. This review was prospectively registered with PROSPERO (CRD42021271452).