Author(s): XU, Z., ZHANG, J., WONG, S., Institution: THE CHINESE UNIVERSITY OF HONG KONG, Country: CHINA, Abstract-ID: 1795

INTRODUCTION
Physical inactivity, defined as not meeting the physical activity recommendations, has become a key priority in global public health policy. Extensive randomized controlled trials (RCTs) aimed at promoting physical activity behavior have been conducted and synthesized in a proliferation of systematic reviews. However, they remain fragmented and heterogeneous with respect to study populations, intervention content, and delivery modes, which poses challenges for healthcare professionals and researchers to assess the total body of evidence on physical activity behavior change interventions. The general adult population represents a major public health target for optimizing primary prevention through behavior modification. Therefore, this umbrella review synthesizes the current evidence on physical activity behavior change interventions in general adults.

METHODS
We systematically searched PubMed, Web of Science, the Cochrane Database of Systematic Reviews, and APA PsycInfo from inception to September 2025. Eligible studies included systematic reviews with meta-analyses of RCTs that examined interventions targeting physical activity behavior change in general adult populations (aged 18 years or older) that were not selected on the basis of pre-existing disease. Outcomes of interest included any measure of change in physical activity behavior. Two reviewers independently performed literature selection, data extraction, and methodological quality assessment using the AMSTAR-2 tool. The overlap in primary RCTs across included reviews was assessed using the corrected covered area (CCA) method.

RESULTS
Forty-one systematic reviews met the inclusion criteria. Of these, 23 focused on digital interventions delivered via electronic or mobile technology (e.g., wearables, smartphones, or computers); seven evaluated interventions grounded in one or more theoretical frameworks (e.g., Social Cognitive Theory or Theory of Planned Behavior); and 11 imposed no restrictions on intervention type. Thirty-six reviews reported statistically significant effects on at least one physical activity outcome at post-intervention. Eight reviews assessed sustained effects during follow-up periods; however, findings were inconsistent. Based on AMSTAR-2 ratings, three reviews were of high quality, 19 of moderate quality, 13 of low quality, and six of critically low quality. After deduplication of 822 primary RCTs across the reviews, 525 unique trials were identified, yielding a CCA of 5.71%, which indicates a modest overlap.

CONCLUSIONS
Although certain intervention strategies, such as digital or theory-based approaches, are effective in promoting physical activity behavior over the course of interventions, fewer than one in five reviews have examined the sustainability of such behavior change after intervention cessation with mixed findings. Future research is needed to develop effective strategies for achieving long-term maintenance of physical activity behavior.