The rhythmic beating of your heart tells a more complex story than most realize. While standard health assessments typically focus on heart rate, the subtle variations between individual heartbeats ...

Most fitness trackers offer a wealth of heart-rate data. Here’s how to make sense of it. By Talya Minsberg If you wear a smartwatch or fitness tracker, you likely already have access to a steady ...

Beth Skwarecki is Lifehacker’s Senior Health Editor and has been writing about health, fitness, and science here since 2015. Beth was the recipient of the 2017 Carnegie Science Award in science ...

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 ...