Resting heart rate and heart rate variability are two terms you may often see associated with each other. And while they’re not the same thing, they do have a close relationship.
Resting heart rate measures the total number of heartbeats detected over one minute in the resting state, while HRV looks at time intervals between adjacent beats. And the greater the variation in those time intervals, the higher the HRV.
“Heart rate and heart rate variability (HRV) are inversely proportional, meaning that when the heart rate increases, the HRV will go down,” says Twyman.
HRV is usually higher in younger individuals and those who are physically fit, notes Klodas. “So higher HRV is often seen in people with lower resting heart rates, and is usually an indicator of higher parasympathetic tone, a more efficient cardiovascular system, and better overall health,” she says.
On the flip side, lower HRV can increase mortality rates15 and make you more susceptible to the effects of stress and disease.
The major exception here is in people with arrhythmias. In that case, the intervals between beats have nothing to do with parasympathetic tone or physical fitness.
Twyman adds that if you want to get an accurate picture of what’s going on, it’s best to measure HRV when you are in a relaxed state, and your resting heart rate is at its lowest. “During exercise, when the heart rate increases with workload, the HRV will become very low as the sympathetic branch of the autonomic nervous system is activated,” he says.
