Beyond mental health, heart rate variability might even provide insight into how well you are ageing. Being chronically stressed fuels inflammation, studies show, and inflammation plays a role in numerous chronic diseases. Since heart rate variability is one way to assess how well the body is handling stress, it could be used to predict inflammation levels and, thus, risk for ageing-related disease, argued one 2024 research review.
Could heart rate variability be a treatment target?
Some researchers think that purposely manipulating heart rate variability could be an effective way to treat various mental and physical health conditions.
Breathwork is perhaps the most accessible way to regulate your heart rate variability, because the heart naturally speeds up and slows down in time with your inhalations and exhalations, says Tim Herzog, a licensed clinical psychologist in Virginia, US, who is also a certified biofeedback practitioner. Herzog recommends that people set aside about 20 minutes, twice a day, to practice slow, mindful breathing – like inhaling for four seconds, then exhaling for six.
More research is needed, though. There are different ways of practising breathwork besides this, and experts need to work out which is best. Still, some studies suggest it’s a promising path to follow. Researchers have found that when people with mental health conditions, including PTSD and depression, practice structured breathing meant to boost their heart rate variability scores, their mental health symptoms tend to decrease.
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Other studies outside the mental health realm – albeit mostly small and preliminary ones – have shown that such breathwork programmes can result in better sleep, lower blood pressure and lessened chronic pain.
Not all scientists are convinced that heart rate variability needs to be purposely altered, though.
Larsson considers heart rate variability “a metric to look at what the underlying conditions are”, but not something that needs to be directly treated.
Bhatt agrees. Heart rate variability often improves when people start adopting healthy behaviours, such as exercising or getting consistent sleep, but “it’s a chicken-and-egg sort of thing”, he says. “Is the heart rate variability improving, per se, what’s important? Or is it what led to it improving?”
How should you track heart rate variability?
Lots of consumer wearables track heart rate variability. But some are dramatically more accurate than others, cautions Karin Steere, an associate professor at the University of Puget Sound in Washington, US. Her research suggests devices that fasten around the chest do a better job than more common styles worn around the wrist.
No matter what kind of wearable you use, she says, remember that heart rate variability is most useful when assessed over time, not at a single moment. Heart rate variability is supposed to change throughout the day. When you’re out for a run, your heart rate variability will naturally look different from what it does at rest. So, looking at a single score will tell you less than watching how it changes over time.
“Every morning, take your HRV, see what that looks like, and then think about what just preceded that,” Steere recommends. “Did I have a really good night’s sleep? Did I have a couple glasses of wine the night before?”
Over time, as you get a sense of your baseline and how your heart rate variability changes depending on your health and behaviour, you can use that data to help you make decisions and track progress, Herzog says.
Maybe you were already feeling sluggish and your heart rate variability data drives home that your system is overtaxed and needs rest. Or perhaps you’ve just started a new exercise regimen but aren’t seeing physical results yet. Since heart rate variability tends to improve with exercise, a higher score could encourage you that your gym sessions really are working. Tracking it, if anything, “ends up really enhancing subjective awareness”, Herzog says.
And if all of this sounds overwhelming? Don’t let your heart skip a beat over it, Bhatt says.
Heart rate variability can be helpful or interesting for people who are highly motivated to track their health data.
But, in Bhatt’s view, there are plenty of metrics that are easier to understand – and probably more important – than variability, such as heart rate, blood pressure, weight, waist circumference and cholesterol levels. “Every adult should know those numbers,” Bhatt says, “and most people aren’t even doing that”.
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