Heart rate variability in police research: a scoping review of objective psychophysiological assessment

Policing places substantial psychological and physiological demands on officers, increasing the risk of adverse health outcomes and impaired performance. As wearable physiological sensing technologies have become more accessible, heart rate variability (HRV) has emerged as a widely used measure of autonomic and psychophysiological regulation. This scoping review synthesized the application of HRV in policing research and identified methodological considerations and future directions. PubMed, Web of Science, MEDLINE, and PsycINFO were systematically searched for primary studies involving police personnel that used HRV as a measure or outcome. Following screening and full-text review, 58 studies comprising 4,764 participants were included. A narrative synthesis identified three broad applications of HRV: (1) health and well-being, (2) stress response and performance, and (3) adaptive regulation. Lower HRV was consistently associated with occupational stress, shift work, poorer recovery, obesity, and metabolic dysfunction, whereas greater physical activity, aerobic fitness, and healthier body composition were associated with more adaptive autonomic profiles facilitating recovery from stress. During acute operational demands, reductions in vagally mediated HRV and greater sympathetic activation were generally associated with poorer performance, while broader HRV measures were linked to fatigue, tactical selection, and operational readiness. Breathing-based interventions, such as HRV biofeedback and mindfulness were associated with improvements in autonomic regulation, recovery, training adaptation, and performance. Despite these encouraging findings, substantial conceptual and methodological heterogeneity limited interpretation of the evidence. As a scoping review, the objective was to characterize the breadth of HRV applications in policing rather than estimate pooled effects. Accordingly, studies were included across diverse designs and HRV applications. HRV was used as an indicator of stress, recovery, autonomic regulation, health, and performance, with marked variation in theoretical frameworks, HRV metrics, sensing technologies, recording protocols, and outcome measures. Collectively, the findings demonstrate that HRV is a feasible objective measure in policing research. Future work should prioritize theory-driven study designs, standardized measurement, reporting, and methodological controls to strengthen objective inference from physiological sensing. Currently, HRV should be interpreted as one component of a broader psychophysiological assessment. It should not be used for personnel selection, fitness-for-duty, or prediction of mental health.