OBJECTIVE: The use of physical activity monitors (PAMs) in the adult population is increasing rapidly and previous systematic reviews are outdated. The objective of this systematic review and meta-analysis is to estimate the effect of PAM-based interventions on physical activity behavior in adults. Furthermore, the impact of intervention, study, and participants characteristics will be investigated.

METHODS AND DESIGN: Randomized controlled trials and randomized cross-over trials including adult participants will be included if the study compares any PAM-based intervention where the participants receive feedback on their physical activity level measured by PAMs, to control interventions where participants do not receive feedback from PAMs. This protocol is detailed according to the recommendations of the Cochrane Handbook, and it is reported according to the preferred reporting items for systematic reviews and meta-analyses protocols statement. The results from the literature search will be presented in a PRISMA flow chart. The effects from individual studies will be summarized in a random effects meta-analysis and the impact of diagnosis of the participants, type of feedback, type of intervention, and control intervention will be investigated in stratified meta-analysis and meta-regressions analysis. The results on daily physical activity, moderate to vigorous physical activity, sedentary time, and adverse events will be presented in a summary of findings table.

DISCUSSION: The results will be useful to researchers, policy makers, and health care professionals when the intention is to increase physical activity in the adult population.

PROSPERO REGISTRATION: CRD42018102719.