The main way that breathwork exercises can slow your heart rate is by helping to counteract the process that elevates it in the first place when you’re feeling stressed out. “Stress and anxiety can activate the sympathetic nervous system, which causes the release of neurotransmitters such as norepinephrine and epinephrine,” says Heather Martin, DO, family medicine physician at telehealth platform K Health who specializes in hypertension (aka high blood pressure). “These chemicals trigger the ‘fight or flight’ response, which is designed to prepare you for reacting to a dangerous situation, primarily by increasing heart rate and respiratory capability and dilating the eyes.”
As the sympathetic nervous system ramps up, there’s a simultaneous “decrease in parasympathetic activity—aka the calm 'rest and digest' processes—which also contributes to a faster heart rate, often felt as racing,” says Erich G. Anderer, MD, chief of neurosurgery at New York University Langone Hospital in Brooklyn. But when the parasympathetic nervous system is dominant, the heart typically only beats about once per second, he adds.
That’s why any breathing exercise to lower heart rate will be one geared toward activating the parasympathetic (and not the sympathetic) nervous system. And that typically happens with deep, slow breaths, says Dr. Martin. Breathing this way also forces you to focus on the exhale part—which often falls by the wayside when you’re stressed and your heart is racing and you’re all but hyperventilating.
That kind of shallow breathing can actually make your heart beat faster because of the relationship between breathing and heart rate, says Dr. Anderer. “In healthy people, we see a temporary increase in heart rate with inhalation followed by a decrease with exhalation,” he says. So, the lengthier exhalations of slow breaths are key for slowing down your heart, too.
“Slow breathing can promote a state of relaxation, which enhances the parasympathetic response, allowing you to ‘rest and digest.’” —Erich G. Anderer, MD, chief of neurosurgery at NYU Langone Hospital
And that’s just one pathway by which slower breaths can physiologically calm the heart. “Slow breathing can also have direct influence on pressure receptors in the vascular and pulmonary systems and promote a state of relaxation, which tends to enhance the parasympathetic response throughout the body and allow you to ‘rest and digest,’” says Dr. Anderer.
A simple breathing exercise to lower your heart rate
Though there isn’t current evidence that one particular breathing exercise is best for lowering heart rate, Dr. Anderer notes that many breathwork practices, largely originating in India and dating back centuries, are “belatedly being actively researched and recommended to patients by many in the medical community for conditions as varied as high blood pressure and depression.” In particular, deep and controlled breathing exercises—and their use for calm and meditation—have their roots in pranayama, one of the eight limbs of yoga.
One adaptation of this measured breathing is called “square breathing,” which can be utilized anywhere, anytime to help slow down the heart rate, says Dr. Martin. Below, she outlines the steps:
- Start by exhaling completely.
- Gently inhale through your nose while counting to four.
- Hold your breath in for a count of four.
- Gently exhale through your mouth for a count of four.
- Hold your breath out for a count of four.
The even repetition of inhaling for four, holding for four, exhaling for four, and then holding again for four is what gives this breathwork practice its square name. You can repeat it as many times as you’d like, says Dr. Martin, allowing your heartbeat to return to its usual speed.
If this exercise doesn’t resonate with you, there are certainly others you can try, too. “There are practices based on a set time or set number of breaths, on equal effort through inhalation and exhalation, on single-nostril breathing, and on focused diaphragmatic breathing,” says Dr. Anderer. And because everyone’s physiology is a little different, different breathwork exercises can be equally effective for a racing heart in different people.
A note of caution: If none of the above seems to help, or if you become lightheaded, dizzy, or short of breath as a result of a racing heart, be sure to seek medical attention “to ensure you are getting adequate amounts of blood to vital organs, and that you don't have an underlying irregular heart rate, which is something that can require treatment,” says Dr. Anderer.