Cohort Study: Inter- and Intraindividual Variability in Daily Resting Heart Rate and its Associations with Age, Sex, Sleep, BMI, and Time of Year

Inter- and intraindividual variability in daily resting heart rate and its associations with age, sex, sleep, BMI, and time of year: Retrospective, longitudinal cohort study of 92,457 adults – PLOS One (free)

Commentary: Normal resting heart rate appears to vary widely from person to person – PLOS (free) AND Normal resting heart rate varies widely – OnMedica (free)