Heart rate variability is one of the main things your smartwatch or fitness tracker measures. Here's what it means.

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 ...

Even greater risk for mortality, CV events in presence of several high-variability metabolic parameters (HealthDay News) — High variability in metabolic parameters is associated with increased risk ...