Does the Samsung smartwatch accurately measure heart rate and heart rate variability?
Samsung smartwatches can reliably measure HR and HRV during sleep, but HRV accuracy degrades significantly during awake periods.
The Samsung smartwatch provides acceptable HR, time-domain HRV, LF, and HF parameters during sleep time. In contrast, during the awake time, AVNN and HR show satisfactory accuracy, and the other HRV parameters have high errors.
Sarhaddi et al. (Thu,) studied this question.