Fitness trackers and smart watches are widely popular wearable devices that measure several types of health metrics, including step count, calories burned, sleep quality, Vo2 max and heart rate.

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 ...

Whether due to stress or an intense cardio workout, most of us have felt our heart racing from time to time. A rise in your heart rate can be perfectly normal given outside circumstances. However, ...

We know the beat of our heart varies over time, increasing with exertion and slowing with rest or meditation. But, stable as those variations may appear, they vary even within those intervals. Dr.

A lower resting heart rate indicates an efficient heart and a higher level of parasympathetic activity. When you’re at rest, your nervous system ideally minimizes sympathetic activity, so you’re ...

Respiratory rate, another metric in the Apple Watch vitals app, shows how many breaths you take per minute. This typically ...

Many parents know that their own pulse or heart rate should be within about 60 to 100 beats per minute. Your child, however, may have a higher pulse rate, depending on their age. Because heart rate ...

Whether brought on by stress, physical activity, or an extra cup of joe in the morning, most of us have all felt our heart rate quicken at one time or another. However, a lower resting heart rate ...