Vagus Nerve Exercises: What the Science Supports and What the Yogis Knew

Scroll through any wellness feed this autumn and you will meet the vagus nerve. People hum into the camera, press ice to their faces, gargle, tap their collarbones, all promising a nervous system "reset". The interest is understandable: many of us live with a body that feels permanently switched on. So which vagus nerve exercises have real evidence behind them, which claims run ahead of the science, and what did the yogis discover long before the hashtag?

What the vagus nerve actually does

The vagus is the tenth cranial nerve. Its name comes from the Latin for "wandering", and it wanders indeed, from the brainstem down to the heart, lungs and much of the digestive tract. It is the main channel of the parasympathetic nervous system, the branch associated with rest, digestion and recovery.

One of its effects is easy to feel. Put two fingers on your pulse and breathe slowly: your heart tends to speed up a little as you inhale and slow down as you exhale. This rhythm is called respiratory sinus arrhythmia, and it is one reason researchers use heart rate variability, or HRV, as an index of vagal influence on the heart.

Vagus nerve exercises with real evidence: slow breathing

The strongest evidence concerns the simplest practice. In 2022, Sylvain Laborde and colleagues published a systematic review and meta-analysis in Neuroscience and Biobehavioral Reviews covering 223 studies of voluntary slow breathing. They found increases in vagally mediated HRV during slow breathing, immediately after a single session, and after multi-session training programmes. The authors suggest slow breathing as a low-cost, low-tech option for prevention and as an adjunct to treatment, with few adverse effects expected.

A 2023 randomised trial from Stanford, led by Melis Yilmaz Balban with Andrew Huberman and David Spiegel among the authors, adds a useful detail. Published in Cell Reports Medicine, it asked 108 people to practise one five-minute exercise daily for 28 days. Cyclic sighing, a double inhale through the nose followed by a long, slow exhale through the mouth, produced a greater increase in positive mood than mindfulness meditation and a larger drop in breathing rate. Anxiety fell in both groups by similar amounts.

The study has clear limits. It was exploratory, registered after it was run, drew mainly on university students, and found no significant change in HRV. I read it as a promising signal that five minutes of exhale-focused breathing can lift mood, from a single trial that deserves replication.

Where the trend runs ahead of the science

Much of the online vocabulary comes from polyvagal theory, developed by Stephen Porges, which links different branches of the vagus to states of safety, fight or flight, and shutdown. Many therapists find its language helpful. Its physiology, however, is contested. In a 2023 paper in Biological Psychology, the psychophysiologist Paul Grossman examined the theory's five core premises and argued that each is either untenable or highly implausible. He describes equating respiratory sinus arrhythmia with general vagal tone as a category mistake.

The honest summary: slow, exhale-focused breathing has solid support for shifting physiology and mood; many of the more dramatic "reset" claims you will see online are untested; and the neat story about nerve branches is a useful metaphor for some people while scientists continue to debate it.

What the yogis knew

Long before HRV monitors, yogis explored the breath as a bridge between body and mind. The Hatha Yoga Pradipika, a fifteenth-century manual attributed to Svatmarama, describes a series of pranayama practices and teaches that as the breath becomes steady, the mind becomes steady. One of them, bhramari, the humming bee breath, uses a long, humming exhale.

The yogis framed these practices in terms of prana, the life force, and I present that as a tradition and a description of lived experience. What strikes me is how precisely their emphasis on long, slow, controlled exhalation matches what physiology now measures. Their language and ours describe a similar territory from different directions.

A practice: five minutes of extended exhale

Try this once a day for two weeks, ideally at the same time.

1. Sit comfortably with your spine upright and your shoulders soft.
2. Inhale gently through the nose for a count of four.
3. Exhale slowly through the nose or pursed lips for a count of six to eight.
4. On some exhales, hum softly, bhramari style, and feel the vibration in your face and chest.
5. Continue for five minutes. If you feel lightheaded, return to normal breathing.
6. Finish by noticing three sensations in your body, then open your eyes.

This is a wellness practice for everyday stress. If you live with a heart, lung or anxiety condition, check with your doctor first, and treat it as a complement to professional care.

For guided support, the Hypnosis Library offers recordings for fear and anxiety, deep sleep and letting go.

Related reading

• Breathwork, Music and the Ecstatic Brain: What Neuroscience Now Confirms
• Self-Hypnosis for Stress: What Two New Studies Reveal
• When the Clocks Go Back: Sleep Science and the Wisdom of Winter

Sources

• Laborde, S., et al. (2022). Effects of voluntary slow breathing on heart rate and heart rate variability: A systematic review and a meta-analysis. Neuroscience and Biobehavioral Reviews. Repository record
• Yilmaz Balban, M., Neri, E., Kogon, M. M., et al. (2023). Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine, 4(1), 100895. Full text
• Grossman, P. (2023). Fundamental challenges and likely refutations of the five basic premises of the polyvagal theory. Biological Psychology, 108589. Zenodo record
• Svatmarama, Hatha Yoga Pradipika (15th century), chapter 2.