OBJECTIVE To provide a broad overview of the state of physical activity (PA) research in the form of (1) definitions of PA, (2) health benefits, (3) prevalence, (4) correlates and (5) interventions. METHODS A high-level overview of published reviews of the literature. RESULTS Regular PA is an effective primary and secondary preventative strategy against at least 25 chronic medical conditions with risk reduction typically in the 20-30% range. While approximately 75% of adults meet recommended PA guidelines, the prevalence is slightly lower for women compared to men, and considerably lower for youth, older adults and those in higher income countries. Motivation, self-efficacy and self-regulation remain consistent correlates of PA. Interventions show PA changes in the small effect size range for adults and youth but the heterogeneity is considerable across studies. Only a few (aggregate of behavioural regulation strategies, supervision, high frequency of contact) reliable moderators of intervention success were identified across study quality, sample characteristics, theory/behaviour change techniques and delivery modes/settings. CONCLUSIONS PA research should continue to examine the mechanisms causing health outcomes, the dose that can lead to clinically relevant changes in health status, the scope and validity of PA surveillance and innovative behaviour change techniques, while improving the reach and duration of PA interventions.