These days, it may seem like there’s a million different data points that you’re supposed to keep track of—hello, steps, sleep, and recovery scores!—and it’s difficult to know which ones are worth ...

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 ...

Add articles to your saved list and come back to them anytime. From the moment our heart starts beating in utero to the day we die, a group of cells in the organ’s top-right corner controls the ...