INTRODUCTION: Physical activity (PA) has considerable benefits for older adults, yet they often face various barriers that hinder participation. Peer-led or peer-supported PA interventions represent a promising strategy to address barriers, such as cost and lack of motivation. Although existing reviews suggest that these interventions improve PA adherence, combining randomised controlled trials (RCTs) with other study designs may weaken their validity. Furthermore, their effects on PA levels and physical function are inconsistent, and their impacts on cognitive abilities, psychosocial well-being and social support, as well as the influence of peer characteristics and programme design, remain unexamined. This review aims to synthesise evidence regarding the effectiveness of peer-led or peer-supported PA interventions across multiple health outcomes and identify possible influencing factors.
METHODS AND ANALYSIS: The search will encompass six English and three Chinese databases, namely, PubMed, Web of Science, Embase, Cumulative Index to Nursing and Allied Literature, PsycINFO, CENTRAL, China National Knowledge Infrastructure, Wanfang Data and the Chinese Biomedical Literature Database. It will cover literature from inception to December 2025. Trial registries will be searched, and a manual search of relevant studies will also be conducted. RCTs that focus on community-dwelling older adults participating in peer-led or peer-supported PA interventions will be included. Outcomes include PA levels, physical function, cognitive function, psychosocial well-being, self-efficacy, social support, health-related quality of life (HRQoL) and programme adherence. Two reviewers will independently screen the literature, extract data and evaluate the risk of bias by using the Cochrane Risk of Bias Tool 2.0. Meta-analyses will be conducted for outcomes reported in at least two studies, and narrative analyses will be performed for others. Subgroup analyses, metaregression, sensitivity analyses and assessments of publication bias will be conducted as appropriate. The Grading of Recommendations, Assessment, Development and Evaluations approach will be used to assess the certainty of evidence.
ETHICS AND DISSEMINATION: Ethical approval is not required because only published data will be used. Results will be disseminated through peer-reviewed publications and conference presentations.
PROSPERO REGISTRATION NUMBER: CRD420251112127.
