The benefits of yoga are now common knowledge. As explored in last month’s issue [See bit.ly/prescribing-yoga-0326], recent research confirms that practicing yoga frequently helps to improve sleep, lower markers of inflammation, improve digestion, and enhance mental clarity and sense of well-being. 

What these benefits have in common is that they are related to the nervous system, helping people achieve what Western medical doctors describe as a “well-functioning” nervous system—one that can adapt to stressors and can fluidly move between the sympathetic branch to deal with stress and the parasympathetic branch, its “rest-and-digest” mode. 

Which brings us to the vagus nerve. This bundle of nerves is a kind of information super-highway between the brain and the body, and although researchers continue to debate the details of its role in regulating the health of body, gut and mind, they agree on its significant contribution to wellness.

In fact, the vagus nerve has become a buzzword in Western yoga classrooms in the last 20 years or so, as general yoga classes now consistently include a discussion of yoga’s contribution to healthy vagal response. The modern medical establishment seems to agree, as more physicians recommend yoga as a way to improve vagal tone.

The Vagus Nerve, Explained

The vagus nerve is a large bundle of fibers that gets its name from the Latin vagus, which means “wandering.” It is the tenth cranial nerve; it exits the brain at the base of the skull and innervates the jaw, neck, throat, heart, lungs and most organs of the torso, including the intestines. The vagus nerve helps regulate many automatic functions of the body, playing a central role in the parasympathetic “rest-and-digest” response and influencing digestion, heart rate, breathing and certain functions of immune activity.

Unfortunately, there is no single agreed-upon way to measure the health of the vagus nerve. Researchers across multiple fields debate both the methods used to assess vagal function and the metrics used to interpret it. There’s also some debate over the degree to which it’s involved in the parasympathetic and sympathetic aspects of the nervous system. 

One way scientists estimate how well the vagus nerve is functioning is by measuring heart rate variability (HRV), the small variations in time between heartbeats. The higher the HRV, the better the physical and mental health outcome. Low HRV can be an indicator of a range of poor health conditions. However, there is consensus that there can be poor—and often severe—health outcomes as a result of low vagal tone, or to the total loss of the communications pathway, such as might happen in a car accident. 

Since testing to measure vagal tone and HRV requires expensive, specialized equipment that isn’t readily available to the general public, how can one evaluate the health of their nervous system? What steps can one take to improve nervous system response? As yoga has integrated vagal health into its practices since its inception, and the medical establishment has “blessed” it as a purveyor of vagal health, let’s look at what yogic wisdom shares. 

Four Yogic Practices for a Well-Functioning Nervous System

Although a number of ancient texts offer postural, breath and mindfulness techniques related to regulating the nervous system, the Yoga Sutras of Patanjali and the Hatha Yoga Pradipika both provide specific practices, many of which align with modern techniques to stimulate the vagus nerve.

1. Resonate the Throat Space with Mantra

In his first book of Yoga Sutras, Patanjali advises that the use of a short, chanted phrase, referred to as mantram practice, is one way to provide prolonged stimulation to the vagus nerve and its surrounding areas. For Patanjali, the sacred syllable of OM is the mantram of choice, partly because the yoga lesson is tied to this sound being a representation of the Divine in all things. Still, practitioners acknowledge that any meaningful, short, repeated phrase provides both the mental one-pointedness and the physiological stimulation that produces a reduction in stress-response. While opinions vary as to whether a gentle engagement around the muscles of the mouth is beneficial or if it ultimately creates more tension in the body-mind, the consensus is that singing or chanting will resonate the vagus nerve. 

2. Resonate the Throat Space with Breath and Sound

Two types of yogic breathing practices are being studied across a range of research fields for their resonating qualities and their ability to stimulate and tone the vagus nerve. Both methods are known for helping to calm the nervous system and quiet the mind, and they happen to help resonate the organs of the head, neck and chest—areas affected by the vagus nerve.

In bhramari, or “bumble-bee breath,” the practitioner begins with the lowest frequency they’re comfortable with. After inhaling slowly through the nose, they exhale through the nose, making a soft, continuous humming sound. Lips are softly closed to vibrate, and teeth remain slightly apart. As the “buzzing’ sound is made, many surrounding nerves in this region of the body are resonating, including those innervating the eyes, inner ear, endocrine glands and facial muscles.

The second breathing practice, ujjayi, often translated as “victorious breath,” produces a soft, steady sound on both the inhale and the exhale. The practitioner gently narrows the throat and closes the mouth, creating a quiet “ha” or ocean-like sound as the breath moves in and out through the nose.

3. Pranayama with a Lengthened Exhalation

Numerous studies across several scientific fields suggest that lengthening the exhale can help reduce stress by activating calming responses in the heart and lungs. Researchers found that extended exhalation might trigger responses similar to the body’s natural sigh reflex, helping regulate the nervous system and improve HRV. It might also engage the baroreceptor reflex—quick actions the body automatically takes to keep blood pressure in a normal range in response to an abrupt change of physical position. This slows the heart rate, quiets the stress response and supports lung function.

Many yogic breathing practices involve lengthening the exhalation, and sometimes the suspension of the breath at the bottom of the exhalation as well. Exploration of these techniques should be done with the guidance of a qualified teacher because of their potent effects on the body-mind. 

4. The Yogic Gaze

In Yoga Sutra 1.31, Patanjali notes: “Sorrow, despair, unsteadiness of the body and irregular breathing further distract the student.” And in BKS Iyengar’s commentary on the Sutra, he notes that these four conditions align with modern medical diagnoses, both psychosomatic and somatopsychic. It’s noteworthy that the above techniques to calm the nervous system come immediately after the Sutra. It’s tempting to say that modern medical science is providing the research to prove how valuable yogic practices can be for our health. And while suffering is present in our lives, yoga is there to help our nervous system respond. ❧

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Patricia Schmidt, C-IAYT, E-RYT 500, YACEP, is a certified yoga therapist specializing in pelvic health, accessible yoga and yoga for cancer support. She is a Franklin Method trainer, Roll Model method teacher and somatic movement specialist. To learn more, visit PLSYoga.com.