Your wearable says your heart rate variability has changed. Now what?

Wearables measure several aspects of health, and heart rate variability might be one of those. It may be surprising when your device informs you that your heart rate variability is high or low, but what does it mean? Elijah Behr, M.D.

, a cardiologist at Mayo Clinic Healthcare in London, explains heart rate variability and how it factors into health. What does heart rate variability measure? “It measures the balance of nerve activity in the body and the way it relates to your heart rate and blood pressure ,” Dr. Behr explains.

The nerve system that heart rate variability relates to is called the autonomic nervous system . It can be thought of as the balance between the effects of adrenaline in the body and the other part of the nervous system, the vagus nerve, Dr. Behr adds.

“From beat to beat, or over periods of time, heart rate variability can be measured in different ways to try to assess this balance within the autonomic nervous system,” he says. What does high or low heart rate variability mean? “In general people who have higher heart rate variability are more likely to have better cardiovascular fitness. Athletes tend to have a very high heart rate variability, for instance,” Dr.

Behr says. People with lower heart rate variability may be likelier to lack cardiovascular fitness or to have underlying heart disease, he explains. Does this mean people with high heart rate variability have nothing to worry about, and those with low heart rate variability should .