Solo or team? A meta-analysis of individual vs. group-based studies on physical activity, functional, psychosocial, and health outcomes.

Social influences, such as group dynamics, social norms, and peer support are assumed to influence physical activity (PA). Burke et al. (2006) found that “true groups” (i.e., those using group dynamics principles) had advantages over other group conditions in terms of PA. Given technological advances and the rise of virtual exercise platforms, we aimed to update and extend these findings. We conducted a meta-analysis of 71 studies (523 effect sizes), primarily experimental (95%), comparing individual and group-based PA conditions on outcomes including PA levels, functional assessments (e.g., flexibility, strength), psychosocial measures (e.g., quality of life, loneliness), and health indices (e.g., body mass index). Using a three-level random-effects model, group-based conditions showed a small but non-significant advantage over individual conditions for PA (g = .071, p = .642), psychosocial (g = .292, p = .214), and health outcomes (g = .125, p = .096). For functional outcomes, a small but significant advantage for groups emerged after outlier removal (g = .164, p = .015). Moderation analysis showed that different types of groups resulted in similar outcomes. The only exception was for “true groups”, whose effect size predicting health outcomes was larger compared to the effect sizes for other group types. Both individual and group -based approaches (in-person or online) may be effective for PA promotion. Future research should explore the underlying mechanisms that optimise each approach for specific populations and settings. Review registration: Registered on PROSPERO (CRD42021271452)