Effectiveness of interventions to maintain physical activity behavior (device-measured): Systematic review and meta-analysis of randomized controlled trials.

Physical activity has many physical, mental, and social health benefits. Interventions can be successful at helping people initiate participation, but there is a lack of evidence about the ability of these interventions to help adults maintain their physical activity. This systematic review and meta-analysis aims to address this evidence gap. We investigated the extent to which successful physical activity interventions with demonstrated success within randomized controlled trials result in maintenance of device-measured physical activity (at least 3 months post-intervention end). Five databases were searched, and 8919 titles and abstracts were screened for eligibility, and 29 trials met the inclusion criteria. Of these, 22 were included in the meta-analysis. We found that 60% to 80% of physical activity behavior was maintained, as equivalent to an additional 45 min/week of moderate-to-vigorous physical activity and 945 steps per day compared with comparators. We also examined trials that randomized participants to maintenance interventions after an initial physical activity intervention (n = 7) and we found small effects (standardized mean difference 0.14, 95% confidence interval [CI] 0.1 to 0.27). The evidence suggests that most (60%-80%) of the increases in physical activity in successful programs are maintained for at least 3 months and there are small effects from providing a maintenance intervention to the public. Registration: CRD42019144585.