The vagus nerve is having a cultural moment, and like most cultural moments, the signal-to-noise ratio is not ideal. On one end, legitimate neuroscience. On the other, dubious wellness claims about ice baths and humming your way to peak performance. The truth is somewhere more interesting than either extreme. The vagus nerve is genuinely central to nervous system regulation, and understanding what it actually does has practical implications for focus, recovery, emotional regulation, and sustainable performance.
The Anatomy, Briefly
The vagus nerve is the longest cranial nerve in the body, the name comes from the Latin for 'wandering.' It originates in the brainstem and travels through the face, neck, chest, lungs, heart, and gut. It is the primary nerve of the parasympathetic nervous system, and it carries information in both directions: from the brain to the organs, and, critically, from the organs back to the brain. Approximately 80% of vagal fibres are afferent, carrying information upward from the body to the brain. This means the body is continuously reporting to the brain about its internal state, and the brain uses that information to calibrate its overall assessment of the situation.
In polyvagal theory, Porges identifies the vagus nerve as having two distinct circuits: the older dorsal vagal circuit, associated with immobilisation and shutdown, and the newer ventral vagal circuit, associated with the social engagement system, the state in which humans feel safe enough to connect, learn, create, and regulate cooperatively with others.
“The vagus nerve is not a wellness concept. It is the biological substrate of your capacity to feel safe, connected, and capable.”
Vagal Tone: The Trainable Variable
Vagal tone refers to the activity level and responsiveness of the vagus nerve, often measured through heart rate variability. Higher vagal tone correlates with faster recovery from stress, lower resting anxiety, better emotional regulation, and stronger immune function. The critical point: vagal tone responds to training. It is not fixed.
Research published in Frontiers in Psychology in July 2025 confirms that vagus nerve stimulation produced measurable improvements in stress, cognitive anxiety, and depression in a population of high performers. An August 2025 randomised controlled trial found that four weeks of vagus nerve stimulation practice produced significant improvements in stress and confidence compared with controls. This is what I mean in Somatic Productivity when I argue that nervous system practices are infrastructure rather than self-indulgence. Building vagal tone through consistent daily practice changes the baseline from which you operate, measurably, cumulatively, in ways that compound.
What Actually Works
Extended exhale breathing, inhale for four counts, exhale for six to eight, directly activates the parasympathetic branch via the vagal pathway. This is the mechanism behind the physiological sigh: the long exhale is the signal to the nervous system that the threat is passing. Cold water on the face activates the mammalian dive reflex, immediately slowing heart rate and increasing vagal activity. Humming and chanting produce vibration that directly stimulates the vagus nerve. Social connection, the kind of attuned, co-regulatory connection that the ventral vagal system supports, is itself a vagal activation. The common thread is this: each practice sends the body a safety signal through a physiological channel.
The Daily Practice
Building vagal tone does not require a dedicated wellness programme. It requires consistent, brief practice integrated into the structure of the day. Morning: the physiological sigh and two minutes of slow extended-exhale breathing shifts the autonomic state before the day's demands begin. Pre-task: a grounding practice, feet flat, orient to the room, three slow breaths, before any high-stakes activity. Recovery: cold water on the face after a depleting interaction resets the system more efficiently than scrolling. These are small. They are consistent. And consistency, as with any training, is what produces the baseline change.
Bart Reevers