When you open your Fitbit app after installing the update, you will see a series of messages. These will detail all of the changes in the update. Fitbit notes that some charts adopted white ...

Heart rate variability measures the variation in time between successive heartbeats, providing insights into the balance between the sympathetic and parasympathetic nervous systems, which influence ...

This article was originally featured on The Conversation. Your heart beats around 100,000 times every day. Heart rate is a key marker of cardiovascular activity and an important vital sign. But your ...

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 ...