Your Fitbit's HRV reading can offer clues about stress and recovery, but your usual numbers matter more than anyone else's.

Heart rate variability (HRV) is the variation in time between heartbeats. Even though your heart beats a certain number of seconds per minute, those beats aren't evenly spaced apart. HRV provides a ...

Heart rate variability (HRV) is the variation in the time between two consecutive heartbeats over a specific period. Doctors may use HRV as an indicator for certain aspects of a person’s health, ...

In healthy older adults, heart rate returned to about 97 percent of resting values after a moderate step test while ...

This is the ultimate heart rate variability deep dive—nuanced, practical, and funny. I'll even share a story involving Andrew ...

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 ...

For those in a hurry—a concise version summarizing only the main points is available on the blog.If asked, "Is this number ...

Facial video estimated heart rate variability with strong agreement against ECG measurements. Heart rate variability ...

It’s been known for decades that heart rate variability (HRV) during labor signals how a fetus is responding to stress. Lower HRV—a lower variation in heartbeats—is even a risk factor for sudden ...