Impact of central adiposity on the heart rate and calorie estimation accuracy of diverse smartwatches and the resulting subjective exercise experience.

Introduction: In light of the growing global trend toward health awareness, wearable technologies like smartwatches have become essential for monitoring physiological indicators such as heart rate (HR). However, their utility faces two critical challenges: a technical disparity between premium and affordable devices and a conceptual gap where objective HR may fail to capture the true subjective strain experienced by diverse populations. Consequently, this study has a dual objective: to evaluate the HR accuracy of four commercially available watches and examine how measurement variations propagate through a standardized HR-derived energy expenditure model; and to investigate the dissociation between objective HR and subjective perceived exertion (RPE) in individuals with elevated central adiposity. Methods: Forty healthy adults ( Results: Premium smartwatches, specifically the Apple Watch and Garmin, demonstrated superior HR precision across all activity phases, maintaining high correlations ( Conclusion: This study confirms that while higher-end sensors offer greater heart rate precision, affordable wearables can provide sufficient HR data to yield consistent energy expenditure estimates when using a standardized mathematical model, supporting their potential utility in large-scale health monitoring. The divergence between objective heart rate and subjective exertion in participants with central adiposity indicates that heart rate alone is an insufficient gauge of exercise intensity. Consequently, personalized weight-management programs should integrate wearable-derived metrics with perceived effort to better account for the unique physiological and psychological strain associated with higher body mass.