From the Oura Ring to the Apple Watch to the Google Pixel — here's what the science really says about the accuracy of their health data ...

If you own a smartwatch or have been around people who own smartwatches, you may have encountered a metric called HRV, or heart rate variability. On the internet and social media, it certainly seems ...

As wearable technology has grown more popular, it’s not just researchers and cardiologists who are paying attention to heart rate. You might be monitoring your own all day long via a fitness tracker ...

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 pulse is not as steady as a precision clock – nor would you ...

You probably check your step count religiously, maybe glance at your heart rate during workouts, and might even pay attention to how many calories your fitness tracker claims you’ve burned. But ...

Plus, doctors’ number-one pick and their take on the devices.

As a certified personal trainer, I tested 14 wearables over eight months while training, running and swimming. Here are the ...

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 ...

Sleep trackers use your resting heart rate, heart rate variability and breathing data to estimate how long you sleep and how much time you spend in each stage.