Here’s what HRV is, how it works and what can cause it to rise or fall.

As a certified personal trainer, I tested 16 wearables while training, running and swimming. Here are the best fitness trackers and watches in 2026.

What is heart rate variability (HRV)? As popular as the metaphor may be, a healthy heart doesn’t beat as regularly as a metronome. In fact, it changes its rhythm with each beat. Heart rate variability ...

This voice experience is generated by AI. Learn more. This voice experience is generated by AI. Learn more. A smartwatch glowing on a runner’s wrist may look authoritative, but wearable data is best ...

Fitness trackers give us unprecedented information about our health, especially when it comes to our hearts. Doctors explain ...

Did you know there’s a number that might let you know how stressed you are, whether you have a cold coming on and how to get into the zone if you’re about to present at a big meeting? You can find ...

Tracking key heart health metrics every day helps you understand how your lifestyle affects your cardiovascular system and empowers you to take proactive steps toward better heart health. Heart ...