Heart rate variability is the time variation between each heartbeat that can show how your body handles stress and recovery.

If you wear a fitness tracker, you've likely seen a stat labeled "HRV" pop up on your screen. But what does it mean, and does it matter? Short for heart rate variability, HRV has become a popular ...

The issue: Many runners (particularly women) report that their fitness trackers tell them they’re exercising in a higher zone ...

It may sound dramatic, but the rate at which your heart is beating plays a key role in how long you’re likely to live. According to expert cardiologists and academic researchers, resting heart rate ...

A recent study showed that the heart rate variability of a dog and its owner adapt to each other during interaction. High heart rate variability is associated with relaxation, while low heart rate ...