A Little Heartbeat Irregularity Can Be Good

Milliseconds of variability, now detected by fitness watches, can improve well-being

- BY LYDIA DENWORTH

EARLIER THIS YEAR I got an Oura ring to track the state of my health. Soon I was obsessing over my sleep and activity scores. The reports were generally positive except for one: heart rate variability, or HRV. That's a measure of how much the time between heartbeats changes. Every morning, in bright red, my ring's app singled out HRV and told me: “Pay attention.”

That didn't sound good, although I had no idea why. Before wearable fitness watches, rings and bracelets became so common and started including HRV as a data point, I had never heard of it. Even among heart doctors, its use has been limited. “I don't think HRV is used in day-to-day clinical medical practice,” says Bryan Wilner, an electrophysiologist at the Baptist Health Miami Cardiac and Vascular Institute. “But it's gained a lot more popularity in regular consumers with these noninvasive monitors.”

Suddenly, we are all paying attention to HRV. And as reams of data are collected from hundreds of thousands of people like me, the measure has the potential to become a far more significant tool for diagnosis and therapy, although it isn't there yet.