Why We Recommend Exhaling During TaVNS Stimulation

Dr. XIAOJane

How Breathing Works With ZenoWell taVNS Sessions

At ZenoWell, some of our most calming session experiences are built around a simple rhythm: 4 seconds of stimulation, followed by 4 seconds of rest.

You will notice this intermittent pattern in modes such as Relax and Medit. And when customers use these modes, we often encourage a matching breathing pattern:

exhale while you feel the stimulation,
inhale during the pause.

This recommendation is not arbitrary, and it is not just a mindfulness cue.

It reflects a broader idea that has become increasingly important in the science of transcutaneous auricular vagus nerve stimulation (taVNS): the effects of stimulation may depend not only on the stimulation itself, but also on the body’s state and timing—especially the timing of breathing.

That is why we see the breathing rhythm in Relax and Medit as more than a comfort feature. We see it as a practical way to make the session feel more aligned with the body’s own regulatory patterns.

Why We Pair the Stimulation Phase With the Exhale

The short answer is this:

we want the stimulation phase to coincide with the phase of breathing that is generally more compatible with vagal regulation and relaxation-oriented physiology.

Across the respiratory cycle, the body does not stay in exactly the same autonomic state. In general:

inhalation is associated with a relative increase in physiological activation and a natural rise in heart rate,
while exhalation is more closely associated with parasympathetic influence, cardiovagal regulation, and a shift toward downregulation.

Because taVNS is designed to work with vagal pathways, this difference matters.

When we encourage users to exhale during stimulation and inhale during the rest phase, we are trying to align the stimulation pulse with a more vagally favorable window. In other words, we are using breathing to help place stimulation into a calmer physiological context.

That is one of the key reasons this pattern is built so naturally into the ZenoWell experience.

Why Relax and Medit Use a 4s On / 4s Off Rhythm

The 4 seconds on / 4 seconds off rhythm used in Relax and Medit creates a natural structure for breathing-linked use.

Instead of delivering a continuous, unbroken stream of stimulation, this intermittent pattern makes it easier for users to settle into a repeating cycle:

stimulation and exhalation,
pause and inhalation,
stimulation and exhalation again.

This rhythm offers several practical advantages.

It can make the session feel:

easier to follow,
more intentional,
less passive,
and more connected to the body’s own pacing.

For many users, this also makes the session feel more meditative. The stimulation becomes part of a repeating breath pattern rather than a separate sensation to ignore.

From our perspective, that matters. A good session is not just about delivering electrical input. It is also about helping the user enter a more stable and coherent state during use.

What the Research Suggests About Breathing and taVNS

Research on respiratory-gated taVNS, sometimes referred to as RAVANS, has shown that breathing phase can influence how vagus nerve stimulation interacts with the body.

Across the literature, researchers have explored how respiratory timing may shape outcomes and mechanisms related to:

stress regulation,
sleep support,
pain-related discomfort,
cardiovascular regulation,
cognitive performance,
overall autonomic function,
brainstem responses involving the nucleus tractus solitarius (NTS),
arousal-related signaling associated with the locus coeruleus–norepinephrine (LC-NE) system,
and inflammation-related regulatory pathways.

This does not mean breathing is simply an optional add-on to taVNS. It suggests that breathing may be a meaningful part of the context in which vagal stimulation is received and processed.

That is why the way stimulation is timed—relative to respiration—has become such an important topic in closed-loop and respiratory-controlled neuromodulation research.

Why Exhalation-Gated taVNS Stands Out

Among the respiratory-timed approaches studied so far, exhalation-gated or expiratory-gated taVNS appears especially compelling.

This is because exhalation is generally associated with:

stronger parasympathetic influence,
greater cardiovagal engagement,
a more relaxation-compatible internal state,
and a more favorable window for downregulation-oriented vagal input.

By contrast, inhalation is usually accompanied by relatively greater sympathetic activation and a natural increase in heart rate. That makes it a less intuitive phase for stimulation when the goal is calm, regulation, or parasympathetic support.

This is one of the clearest reasons we encourage users in Relax and Medit modes to sync stimulation with the exhale.

We are not claiming that every person will respond in exactly the same way, or that all stimulation goals should always follow the same respiratory rule. But based on the current direction of the evidence, the exhale phase has one of the strongest physiological rationales for taVNS timing.

Why the Pause Phase Pairs Naturally With Inhalation

Just as important as exhaling during stimulation is inhaling during the pause.

In our Relax and Medit modes, the 4-second rest interval gives the body a natural moment to receive no stimulation. We often encourage users to use that quiet space for inhalation.

Why?

Because this creates a simple alternation:

stimulation during exhalation
rest during inhalation

This breathing-stimulation rhythm can help the full session feel more orderly and more embodied. Instead of overlapping stimulation with the inhale phase—which is generally a more activating part of the respiratory cycle—the pause phase gives room for inhalation to happen on its own.

That pattern is elegant in its simplicity:

the exhale supports release and settling,
the stimulation arrives during that more vagally favorable phase,
the inhale returns during the rest period,
and the cycle repeats.

For many users, this creates a smoother and more intuitive experience than breathing without any relationship to the stimulation pattern.

Why This Matters for Relaxation and Meditation-Oriented Use

The Relax and Medit modes are not just defined by stimulation settings. They are also defined by the kind of experience they are meant to support.

When someone chooses these modes, the goal is often not intensity—it is calm, unwinding, grounding, and recovery from mental or physical tension.

That is exactly why breathing matters.

A stimulation rhythm that is paired with exhalation can help the session feel:

more settling,
more rhythmically predictable,
more aligned with relaxation practices,
and easier to integrate into quiet moments, meditation, or evening wind-down routines.

For us, this is one of the biggest benefits of combining breathing with intermittent taVNS. It does not just change the session technically—it changes the session experientially.

Why This Fits the Direction of Closed-Loop Neuromodulation

One of the most important directions in taVNS research is the move toward closed-loop neuromodulation—systems that respond to the user’s physiological state in real time.

Breathing is one of the most practical signals for this because it is:

rhythmic,
measurable,
trainable,
and strongly linked to autonomic function.

The principle behind many respiratory-gated systems is simple:
deliver stimulation when the body may be most receptive to it.

Our breathing guidance in Relax and Medit follows that same principle in a practical, user-friendly way.

Even without full hardware-based respiration sensing, a user can still follow the body-aware timing logic by pairing:

stimulation with exhalation
rest with inhalation

That is one reason we see this pattern as both scientifically meaningful and easy to use in real life.

How We Think About It at ZenoWell

At ZenoWell, we do not see breathing as separate from the session.

When we encourage users in Relax and Medit modes to exhale during stimulation and inhale during the pause, we are trying to help them do something very simple:

match the stimulation rhythm to the body’s own calming rhythm.

The goal is not to overcomplicate the experience. The goal is to make it more natural.

We believe that the intermittent 4s on / 4s off pattern makes this especially intuitive. It creates space for a breath-linked routine that is easy to learn and easy to repeat:

feel the stimulation,
breathe out,
feel the pause,
breathe in,
and continue.

That rhythm captures much of what we want the ZenoWell experience to be: calm, guided, embodied, and aligned with physiology.

A Simple Way to Use Relax and Medit Modes

If you are using Relax or Medit, a simple approach is:

sit or lie in a comfortable position,
soften the shoulders, jaw, and face,
when stimulation begins, let the breath flow out gently,
when stimulation pauses, allow the inhale to return naturally,
keep the breathing comfortable rather than forced,
and let the rhythm repeat without overthinking it.

There is no need to make the exhale dramatic or overly long. A gentle, natural exhalation is usually enough. The idea is not perfect control. The idea is coordination.

In many cases, that coordination alone can make the session feel more intuitive and more calming.

Final Thoughts

At the beginning of this article, we mentioned a simple ZenoWell rhythm:

4 seconds of stimulation, 4 seconds of rest.
And with it, a simple breathing cue:

exhale during stimulation, inhale during the pause.

Now the reason should be clearer.

We recommend this pattern because current research suggests that breathing phase matters, and that exhalation may offer the most physiologically favorable window for vagal stimulation, especially in relaxation-oriented use. Our intermittent Relax and Medit rhythm makes it easy to put that idea into practice in a way that feels natural and accessible.

For us, this is one of the most meaningful ways to bring together wellness design and physiological insight.

At ZenoWell, we want taVNS to feel not only effective in design, but also intuitive in the body.

That is why, in Relax and Medit, we encourage a simple rhythm:

when you feel the stimulation, breathe out.
when the stimulation pauses, breathe in.

References:

Chavez-Cerda, J., Acedo Reina, E., Ngan Yamb, M.-A., Raffoul, R., Vande Perre, L., Verstraeten, M., Morrison, E. I. G., Doguet, P., Garnier, J., Delbeke, J., El Tahry, R., & Nonclercq, A. (2024). Proof-of-concept of respiration-triggered vagus nerve stimulation to treat epilepsy. In IEEE Medical Measurements & Applications 2024. http://hdl.handle.net/2078.1/287281
de Faria, G. M., Lopes, E. G., Tobaldini, E., Montano, N., Cunha, T. S., Casali, K. R., & de Amorim, H. A. (2024). Advances in non-invasive neuromodulation: Designing closed-loop devices for respiratory-controlled transcutaneous vagus nerve stimulation. Healthcare, 12(1), 31. https://doi.org/10.3390/healthcare12010031
Garcia, R. G., Cohen, J. E., Stanford, A. D., Gabriel, A., Stowell, J., Aizley, H., Barbieri, R., Gitlin, D., Napadow, V., & Goldstein, J. M. (2021). Respiratory-gated auricular vagal afferent nerve stimulation modulates brain response to stress in major depression. Journal of Psychiatric Research, 142, 188–197. https://doi.org/10.1016/j.jpsychires.2021.07.046
Garcia, R. G., Lin, R.-L., Lee, J., Kim, J., Barbieri, R., Sclocco, R., Wasan, A. D., Edwards, R. R., Rosen, B. R., Hadjikhani, N., & Napadow, V. (2017). Modulation of brainstem activity and connectivity by respiratory-gated auricular vagal afferent nerve stimulation (RAVANS) in migraine patients. Pain, 158(8), 1461–1472. https://doi.org/10.1097/j.pain.0000000000000939
Garcia, R. G., Staley, R., Aroner, S., Stowell, J., Sclocco, R., Napadow, V., Barbieri, R., & Goldstein, J. M. (2022). Optimization of respiratory-gated auricular vagus afferent nerve stimulation for the modulation of blood pressure in hypertension. Frontiers in Neuroscience, 16, Article 1038339. https://doi.org/10.3389/fnins.2022.1038339
Meints, S. M., Garcia, R. G., Schuman-Olivier, Z., Datko, M., Desbordes, G., Cornelius, M., Edwards, R. R., & Napadow, V. (2022). The effects of combined respiratory-gated auricular vagal afferent nerve stimulation and mindfulness meditation for chronic low back pain: A pilot study. Pain Medicine, 23(9), 1570–1581. https://doi.org/10.1093/pm/pnac051
Napadow, V., Edwards, R. R., Cahalan, C. M., Mensing, G., Greenbaum, S., Valovska, A., Li, A., Kim, J., Maeda, Y., Park, K., & Wasan, A. D. (2012). Evoked pain analgesia in chronic pelvic pain patients using respiratory-gated auricular vagal afferent nerve stimulation. Pain Medicine, 13(6), 777–789. https://doi.org/10.1111/j.1526-4637.2012.01385.x
Paleczny, B., Seredyński, R., & Ponikowska, B. (2021). Inspiratory- and expiratory-gated transcutaneous vagus nerve stimulation have different effects on heart rate in healthy subjects: Preliminary results. Clinical Autonomic Research, 31(2), 205–214. https://doi.org/10.1007/s10286-019-00604-0
Sclocco, R., Garcia, R. G., Kettner, N. W., Fisher, H. P., Isenburg, K., Makarovsky, M., Stowell, J. A., Goldstein, J., Barbieri, R., & Napadow, V. (2020). Stimulus frequency modulates brainstem response to respiratory-gated transcutaneous auricular vagus nerve stimulation. Brain Stimulation, 13(4), 970–978. https://doi.org/10.1016/j.brs.2020.03.018
Sclocco, R., Garcia, R. G., Kettner, N. W., Isenburg, K., Fisher, H. P., Hubbard, C. S., Ay, I., Polimeni, J. R., Goldstein, J. M., Makris, N., Toschi, N., Barbieri, R., & Napadow, V. (2019). The influence of respiration on brainstem and cardiovagal response to auricular vagus nerve stimulation: A multimodal ultrahigh-field (7T) fMRI study. Brain Stimulation, 12(4), 911–921. https://doi.org/10.1016/j.brs.2019.02.003
Szulczewski, M. T. (2022). Transcutaneous auricular vagus nerve stimulation combined with slow breathing: Speculations on potential applications and technical considerations. Neuromodulation: Technology at the Neural Interface, 25(3), 380–394. https://doi.org/10.1111/ner.13458
Szulczewski, M. T., D’Agostini, M., & Van Diest, I. (2023). Expiratory-gated transcutaneous auricular vagus nerve stimulation (taVNS) does not further augment heart rate variability during slow breathing at 0.1 Hz. Applied Psychophysiology and Biofeedback, 48(4), 323–333. https://doi.org/10.1007/s10484-023-09584-4
Tian, Q.-Q., Cheng, C., Liu, P.-H., Yin, Z.-X., Zhang, M.-K., Cui, Y.-P., Zhao, R., Deng, H., Lu, L.-M., Tang, C.-Z., Xu, N.-G., Yang, X.-J., Sun, J.-B., & Qin, W. (2023). Combined effect of transcutaneous auricular vagus nerve stimulation and 0.1 Hz slow-paced breathing on working memory. Frontiers in Neuroscience, 17, Article 1133964. https://doi.org/10.3389/fnins.2023.1133964
Tian, Q.-Q., Cheng, C., Yang, X.-J., Sun, J.-B., Qin, W., & colleagues. (2024). Combined transcutaneous auricular vagus stimulation (taVNS) with 0.1 Hz slow breathing enhances insomnia treatment efficacy: A pilot study. Brain Stimulation, 17(1), 4–6. https://doi.org/10.1016/j.brs.2023.11.018
Yu, Y., Ling, J., Yu, L., Liu, P., & Jiang, M. (2022). Closed-loop transcutaneous auricular vagal nerve stimulation: Current situation and future possibilities. Frontiers in Human Neuroscience, 15, Article 785620. https://doi.org/10.3389/fnhum.2021.785620