You’ve probably heard about the vagus nerve in a yoga or meditation class, usually described as something that helps calm the mind. But that’s only a small part of what this nerve can do.

Why did we dedicate a full article to it? Because it has enormous potential to impact both body and mind. And because, specifically, you can consciously activate it to improve alertness, calm yourself quickly, shift your mood, and enhance your ability to learn.

*Much of the information in this article comes from The Huberman Lab podcast episode “Control Your Vagus Nerve to Improve Mood, Alertness & Neuroplasticity” by neuroscientist Andrew Huberman, PhD.

What Is the Vagus Nerve and How Does It Work?

The vagus nerve is the longest nerve in the autonomic nervous system. It runs from the brainstem all the way to the lower intestine, connecting the brain to nearly all vital organs: the heart, lungs, stomach, intestines, pancreas, liver, kidneys, and more.

This nerve is a key component of the autonomic nervous system, which is divided into two branches:

• Sympathetic nervous system: Activates rapid responses to stress, emergencies, or danger, preparing the body for action. It drives the fight-or-flight response. Effects: Increases heart rate, blood pressure, breathing, and sweating, while slowing digestion.

• Parasympathetic nervous system: Responsible for calming the body, promoting recovery, and maintaining internal balance (homeostasis). Effects: Lowers heart rate, reduces blood pressure, stimulates digestion, and promotes relaxation.

The vagus nerve receives both chemical information (such as gut serotonin levels) and mechanical information (such as lung expansion during breathing). That’s why it can be stimulated through sensory or motor techniques.

The Parasympathetic Path: How to Activate the Vagus Nerve to Relax

Here are four evidence-based techniques to activate the vagus nerve and calm yourself quickly.

The Physiological Sigh

The physiological sigh is a breathing technique that lowers heart rate and calms you almost instantly:

• Take two consecutive inhales through the nose: the first long and deep, the second short and quick.

• Exhale slowly and fully through the mouth, emptying the lungs.

This is a powerful tool for moments of intense stress, panic attacks, or anytime you need to quickly slow things down.

What’s the science behind it? It works through heart rate variability (HRV). This pathway involves neurons that slow down or speed up heart rate (BPM). The vagus nerve can influence this directly through breathing.

When you inhale, the lungs expand and the diaphragm moves downward, giving the heart more space to expand. Blood flows slightly more slowly through the heart, sending a signal to the sympathetic nervous system to increase heart rate. In other words, inhaling speeds up BPM. Exhaling does the opposite—it slows BPM down.

The physiological sigh also helps increase HRV. Why does that matter? A higher HRV means better athletic performance, easier training, and faster recovery. Low HRV suggests the body isn’t adapting well—it doesn’t activate when needed or relax when it should.

The best part: it’s easy, takes less than 30 seconds, and you can repeat it several times a day.

A Neck Stretch

A large portion of the vagus nerve runs along the sides of the neck. To stimulate it, do the following:

• Sit facing a table.

• Place your hands palms down, with your elbows resting on the edge of the table.

• Push your elbows and shoulders downward, away from your ears.

• Turn your head up and to the right. Hold for a few seconds.

• Repeat on the other side, turning your head up and to the left.

Humming

This technique may sound a bit strange, but it’s very effective. Several branches of the vagus nerve are located in the larynx. When you hum, the vibrations stimulate the vagus nerve.

Think of humming as a mix between an H and an M: “hhhmmm.” To activate the parasympathetic response, extend the H sound more than the M. Try to feel the vibration moving down the neck, from the back of the throat toward the chest. Sensory-wise, it’s similar to gargling.

Facial Cold Exposure

Pepe Lanusse, a certified Wim Hof Method instructor, shared another way to activate the parasympathetic vagal response through localized cold therapy. It consists of submerging only your face in a bowl of ice water (or in an ice bath). Cooling the face triggers a strong relaxation response.

“That’s why, in moments of panic, stress, or fear, it’s helpful to put your face in ice."

The Sympathetic Path: How to Use the Vagus Nerve to Activate and Boost Energy

This protocol is simple: move the large muscles of the body—legs and core. Light calisthenics, a warm-up, jumping, jogging. It sounds basic, but the effects are impressive.

Activation

This protocol stimulates the release of adrenaline, which activates the sympathetic nervous system via the vagus nerve. The result: increased alertness, focus, and motivation.

It’s especially useful on days when you feel low-energy, unmotivated, and completely unwilling to work out or move.

Learning

When you activate the vagus nerve through exercise, acetylcholine is also released—a key molecule for neuroplasticity. This improves the brain’s ability to learn, adapt, and form new connections. Ideal for studying or preparing presentations, without relying on caffeine.

As children (and into our early 20s), neuroplasticity is naturally high, making learning easier. In adulthood, most of our neural maps are already established. To activate adult neuroplasticity, we need alertness and focus—both achieved through movement involving large muscle groups.

Important: You don’t need intense, exhausting exercise. Moderate movements that engage the legs and core are enough.

Cold Exposure and the Vagus Nerve: A Double Impact

Cold-plunging offers a kind of “double benefit” for the autonomic nervous system and the vagus nerve.

Cold exposure initially puts the body into fight-or-flight mode, activating the sympathetic nervous system. Adrenaline is released, heart rate and breathing increase, and blood vessels constrict to preserve heat in the core (where vital organs are).

At this point, the body works to regulate core temperature and restore balance. This triggers a parasympathetic response: breathing stabilizes, heart rate drops, and relaxation begins.

Benefits of cold-plunging for the vagus nerve:

• Strengthens autonomic regulation

• Reduces cortisol (stress) levels in the short and long term

• Improves HRV and muscle recovery

• Enhances mood

• Increases energy and cognitive function

Boost your brain health and overall well-being with our Ice Baths. They’re easy to use, comfortable, and allow you to practice cryotherapy anytime, anywhere.

*This article is for informational purposes only and does not replace medical advice. Consult a healthcare professional before starting any cold exposure practice—especially if you have heart conditions, hypertension, or other health issues.