Everything you need to know about photoplethysmography (PPG), the technology behind heart rate measurements in fitness watches and smart rings. When you purchase through links on our site, we may earn ...

Heart rate variability (HRV) is the variation in the time between two consecutive heartbeats over a specific period. Doctors may use HRV as an indicator for certain aspects of a person’s health, ...

Active heart rate measures a person’s heart activity during exercise. People can use heart rate zones to optimize workouts by ensuring that the heart rate stays within the ideal range. A person can ...