How does optical heart rate monitoring work?
When your heart beats, it pumps blood to your arteries, making the blood flow stronger and reducing the amount of returning light. Between the heart beats, the blood flow is weaker in your wrist, and more light is reflected back. Measuring the time between high- and low-light intensities enables the device to measure beat-to-beat time intervals and calculate heart rate from that data.
Measuring the time between high- and low-light intensities enables the device to measure beat-to-beat time intervals and calculate heart rate from that data.
