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 ...

That tension becomes especially clear with heart rate zone training, a popular five-tier system that endurance athletes use to measure effort and fine-tune performance. The well-known formula is ...

Heart rate variability during sleep can predict stroke, depression or cognitive dysfunction years in advance, according to new research presented at the European Academy of Neurology Congress. The ...

Here’s what this health metric really indicates, according to cardiologists. Fact checked by Isaac Winter Reviewed by Vivek Cherian, MD Heart rate variability (HRV) is the difference in the timing ...