Understanding how your body works can be the key to reducing stress. For example, you’re probably aware of your fight-or-flight response—the body’s way of preparing itself when it believes it’s being threatened. What happens is your sympathetic nervous system is activated, pumping adrenaline and glucocorticoid steroids into your system that give you hyper focus, energy, and strength to handle the situation.
Fight-or-flight was a survival mechanism during hunter-gatherer times, when the threat of wild animals was real. Today, however, it’s often triggered by non-life-or-death events, such as the evening news, tight deadlines, or traffic.
On the flipside of fight-or-flight is rest-and-digest. It’s the body’s way of rebalancing itself after the danger has passed. In this case, your parasympathetic nervous system is in charge, decreasing your heart rate and blood pressure and providing a sense of calm.
Sometimes, though, the body has a hard time getting back into rest-and-digest. It stays in a state of stress and anxiety. When this happens, it’s often due to your vagal tone, which is the activity in your vagus nerve, says Kevin Tracey, MD, author of The Great Nerve: The New Science of the Vagus Nerve and How to Harness Its Healing.
“[The vagus nerve] is the information superhighway,” explains Tracey, a neurosurgeon and scientist in the field of vagus nerve stimulation. “It’s the conduit between the brain and the organs in your body that are functioning all day long. The vagus nerve carries information that allows your brain to assess the current status of every organ and to adjust the current output of every organ. And the result of that is balance.”
The vagus nerve is the main driver of the parasympathetic nervous system, or rest-and-digest. Made up of 200,000 fibers, it originates at the brain stem, then runs down each side of your neck before it branches out to the organs in your chest and abdomen. High vagal tone is associated with a relaxed, calm state, while low vagal tone corresponds to chronic stress and anxiety.
How to Stimulate Your Vagus Nerve to Calm Your Body
Instead of simply being a passenger in your body, it’s possible to intentionally stimulate your vagus nerve to return to a state of calm. One of the most accessible methods is your breath.
Deep breathing is the conscious deepening of your breath, engaging the diaphragm, which is the muscle at the base of your lungs. When you take a deep breath, it signals your vagus nerve to activate a parasympathetic response. The vagus nerve sends a “slow down” signal to the heart, lengthening the time between heartbeats and producing a body that can more efficiently shift from stress to relaxation.
“Prolonging the time to the next heartbeat is the basis of heart rate variability,” says Tracey. ”The reason that’s important in physiology is you want to time your heartbeat to your breathing. When you inspire, you maximize the filling of your heart with unoxygenated blood. And when you expire, you accelerate the emptying of your heart with oxygenated blood.”
Tracey says different kinds of breathing modalities can impact heart rate variability. He suggests breathing in through your nose to a count of three and breathing out through pursed lips on a count of seven, similar to how you would blow out a candle.
“It’s breathing on the order of about six breaths per minute,” says Tracey. “That has been shown to optimize the filling and emptying function of the heart.”
Another breathwork method is Navy SEAL box breathing. Breathe in on a count of four, hold for count of four, breathe out on count of four, and hold for a count of four.
“I encourage my friends and family to try different methods and follow their heart rate and see the methods that efficiently slow the heartbeat,” says Tracey.
While studies vary on its effectiveness, Tracey also recommends meditation. While a direct link to vagal tone isn’t proven, meditation is associated with a lower resting heart rate and improved heart rate variability.
“I call it my Pascal’s Wager,” says Tracey. “I exercise regularly, get enough sleep, and eat a balanced diet. I try to stay socially engaged with purpose. If I live a long healthy life because I’m doing these things that I don’t mind doing, that’s great. And if they don’t work, I may never know. These things may all increase health span, which in some ways is as important or more important than lifespan.”
By understanding how your body works, you won’t always need to feel like a victim to its instinctual responses. Armed with knowledge and tools, you can take the steering wheel and feel like you’re more in control.
