The main way breathing exercises can slow your heart rate is to help counteract the process that elevates it in the first place when you’re feeling stressed. “Stress and anxiety can activate the sympathetic nervous system, which causes the release of neurotransmitters such as norepinephrine and epinephrine,” explains Heather Martin, DOfamily doctor at telehealth platform Health K who specializes in hypertension (i.e. high blood pressure). “These chemicals trigger the ‘fight or flight’ response, which is designed to prepare you to react to a dangerous situation, primarily by increasing heart rate and breathing capacity and dilating your eyes.”
As the sympathetic nervous system speeds up, there is a “simultaneous decrease in parasympathetic activity – i.e. the quiet processes of ‘rest and digest’ – which also contributes to a frequency faster heart rate, often felt like a race,” 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.
This is why any breathing exercise to lower the heart rate will be geared towards activating the parasympathetic (and not the sympathetic nervous system). And that usually happens with deep, slow breaths, says Dr. Martin. Breathing this way also forces you to focus on the exhale part, which is often ignored when you’re stressed, your heart is racing and you’re hyperventilating.
This kind of shallow breathing can actually make your heart race. faster because of the relationship between breathing and heart rate, says Dr. Anderer. “In healthy people, we see a temporary increase in heart rate on inspiration followed by a decrease on expiration,” he says. So the longer exhalations of slow breaths are also key to slowing down your heart.
“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 way in which slower breaths can physiologically calm the heart. “Slow breathing can also directly influence 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 allows you to ‘rest and digest’. “, explains Dr. Anderer.
A simple breathing exercise to lower your heart rate
Although there is no current evidence that any particular breathing exercise is best for lowering heart rate, Dr. Anderer notes that many breathing practices, largely originating in India and dating back to centuries, are “belatedly 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.
An adaptation of this measured breathing is called “square breathing,” which can be used anywhere, anytime to help slow the heart rate, Dr. Martin says. Below she outlines the steps:
- Start by exhaling completely.
- Inhale slowly through your nose for a count of four.
- Hold your breath for a count of four.
- Exhale slowly through your mouth for a count of four.
- Hold your breath for a count of four.
The regular repetition of inhaling for four, holding for four, exhaling for four, then holding for four is what gives this breathing practice its square name. You can repeat this as many times as you like, says Dr. Martin, allowing your heart rate to return to its usual rate.
If this exercise does not suit you, you can certainly try others. “There are practices based on a set time or set number of breaths, equal effort through inhale and exhale, single nostril breathing, and focused diaphragmatic breathing,” says Dr. Anderer. And because everyone’s physiology is a little different, different breathing exercises can be just as effective for a racing heart in different people.
A note of warning: if none of the above seems to help, or if you experience lightheadedness, lightheadedness, or shortness of breath from a rapid heartbeat, be sure to seek medical attention “for you ensuring that you are getting sufficient amounts of blood to vital organs and that you do not have an underlying irregular heartbeat, which may require treatment,” Dr. Anderer says.