Heart Rate Variability

Heart rate variability (HRV) refers to the natural fluctuations in the time interval between heartbeats.

It is a measure of the physiological balance between the sympathetic (arousing) and parasympathetic (calming) branches of the autonomic nervous system.

Higher HRV is generally associated with good cardiovascular health, while lower HRV is associated with increased risk of death from cardiovascular disease.

HRV can be measured using an electrocardiogram (ECG) or a wearable device such as a smartwatch or fitness tracker.