Introduction: Our goal was to assess the validity of monitoring heart rate (HR) and energy expenditure (EE) while sitting or light-to-vigorous physical activity with four popular wrist worn wearables (Apple Watch Series 4, Polar Vantage V, Garmin Fenix 5, Fitbit Versa). Methods: 25 individuals performed 5-min of sitting, walking and running at different velocities (i.e., 1.1, 1.9, 2.7, 3.6, 4.1 m⸱s-1), as well as intermittent sprints while wearing the four different wearables. The HR and EE were compared to common criterion-measures (Polar-H7 chest belt; indirect calorimetry for EE). Results: For monitoring HR at different exercise intensities, the standardized typical errors (sTEE) were 0.09-0.62, 0.13-0.88, 0.62-1.24, and 0.47-1.94 for the Apple Watch, Polar Vantage V, Garmin Fenix 5 and Fitbit Versa. Depending on exercise intensity, the corresponding Coefficients of Variance (CV%) ranged from 0.9-4.3%, 2.2-6.7%, 2.9-9.2%, and 4.1-19.1%. For monitoring EE at different exercise intensities, the sTEE were 0.34-1.84, 0.32-1.33, 0.46-4.86, 0.41-1.65 for the Apple Watch, Polar Vantage V, Garmin Fenix 5 and Fitbit Versa. Depending on exercise intensity, the corresponding CV% ranged from 13.5-27.1%, 16.3-28.0%, 15.9-34.5%, and 8.0-32.3%. Conclusion: The Apple Watch Series 4 provides the highest validity (i.e., smallest error rates) when measuring HR while sitting or light-to-vigorous physical activity, followed by the Polar Vantage V, Garmin Fenix 5 and Fitbit Versa, in that order. The Apple Watch and Polar Vantage V are suitable for measuring HR validly at the intensities tested, but HR data provided by the Garmin Fenix 5 and Fitbit Versa should be interpreted with caution due to higher error rates at certain intensities. None of these four wrist-worn wearables should be employed to monitor EE at the intensities and durations tested.     «

Introduction: Our goal was to assess the validity of monitoring heart rate (HR) and energy expenditure (EE) while sitting or light-to-vigorous physical activity with four popular wrist worn wearables (Apple Watch Series 4, Polar Vantage V, Garmin Fenix 5, Fitbit Versa). Methods: 25 individuals performed 5-min of sitting, walking and running at different velocities (i.e., 1.1, 1.9, 2.7, 3.6, 4.1 m⸱s-1), as well as intermittent sprints while wearing the four different wearables. The HR and E...     »