Part Two: Understanding the Breath and Nervous System


Part Two: Understanding the Breath and Nervous System

If you haven’t checked out Part One of this four part breath work series, A Trauma Aware Approach to Breath Work  I highly suggest you do so. We break down why a trauma aware and trauma informed approach is critical when teaching and coaching breath work.

Now we will dive in to the nuances and connection of the breath and nervous system to reveal exactly why a trauma aware/informed approach supports our clients best.


What is breath work?

We can’t talk about breath work without first acknowledging what the breath is. To breathe is to be alive and breathing is the most basic physiological process that is required for living. Pranayama, which is often used to refer to “breath work” is the one of the 8 limbs of yoga. Prana, means “life force”. Yama means “extension or control”. 

The breath is automatic but we can also control it.

In order to control or manipulate it, we have to genuinely understand it. At a foundational sense, for me, breath work is simply about developing a relationship with our breath. Different pranayama techniques have different effects on the mind and body and its important to understand this as we come to any practice. 

Kristine Weber, in her Ebook The Subtle Secrets of Pranayama (2018)  states “Your breath is your lifeline, it is your ally, your friend, and your counselor. It is wise, and its intelligence maintains your very existence. Rather than “breath control” or “breath mastery” we can think about pranayama as breath exploration.” I think this is so beautiful and how we should all be coming to a breath work practice.

Breath work is NOT a competition or something to be forced. This practice begins with gaining awareness and moving towards exploration to find ways in which connecting with your own breath may serve and support you.


Basic Breath Anatomy

Breathing is a complex process that involves:

  • Diaphragm
  • Lungs
  • Nose, airways
  • Heart
  • Brain
  • Blood vessels
  • Intercostal muscles
  • Muscles of the neck, shoulders, back

Your diaphragm is the main muscle in breathing which sits below the rib cage and above the stomach cavity. In short here is what happens when we breathe in and breath out anatomically:

Inhale: We breathe in. Air enters the nose and goes down in to the lungs which means our lungs inflate. As the lungs inflate our diaphragm contracts down creating an expansion at the belly. 

Exhale: We breathe out. Our lungs deflate as air exits the nose. As our lungs deflate our diaphragm will release back up and the belly will fall back down. 

Here is a simple picture for visual representation : Breathing Mechanics


The Breath and Nervous System

Your breath is an automatic process that is controlled by your brain (medulla oblongata) and the autonomic nervous system (Ikeda et al, 2017). The autonomic nervous system (ANS) is a part of the peripheral nervous system and controls all involuntary or automatic processes like breathing, heart rate and digestion. 

When it comes to breathing, your brain is always (automatically) adjusting your breath according to what is needed whether you are running from danger, working out at the gym, eating a meal or sitting at your desk reading a book (Novotny and Kravitz, 2017).  This is for our survival, safety and overall well being. 

The link between the breath and nervous system has been acknowledged from the beginning as seen in this verse from the Hatha Yoga Pradipika . “Respiration being disturbed, the mind becomes disturbed. By restraining respiration, the Yogi steadies the mind.” 

What we also know from much of the research on Polyvagal Theory, done by  Dr Stephen Porges, is that autonomic nervous system is a main influencer in how we think, feel and behave. The ANS is the controller of our lives. Therefore, breathing, because it is controlled by the ANS will have an intertwined relationship with how we think, feel and interact with the world around us.

In order to understand more on breath work and the nervous system we need a short lesson in the Autonomic Nervous System.

The autonomic nervous system as 2 main branches, sympathetic and parasympathetic.

  • Sympathetic Nervous system (SNS) = mobilization, fight, flight
  • Parasympathetic Nervous system (PNS) = rest, digest, safety

*Please note: The parasympathetic nervous system technically has 2 pathways or branches based on Polyvagal theory (Dr. Stephen Porges).

  • Pathway 1 = Ventral Vagal which is that rest, digest, social connection and safety
  • Pathway 2 = Dorsal vagal which is shut down, freeze and immobilization

*Please note: When it comes to the nervous system we are never fully in 1 state or another (meaning 1 state is never “on” while the other state is “off”). Think of this as more of an influence and the state that has the influence is in control of our thoughts, feelings and actions.  


The Vagus Nerve, Heart and Lungs

The autonomic nervous system controls the breath through the inner workings of the vagus nerve.  The vagus nerve is the largest nerve (actually a bundle of nerves) in the body that travels from the brain down to the stomach (you can see the vagus nerve here). The vagus nerve is the main influencer of the autonomic nervous system and innervates and connects with the heart, diaphragm and lungs.

The vagus nerve connects the brain to the sinoatrial node (SA node) in the heart, which is the heart's natural pacemaker. Heart rate variability is the beat-to-beat variation in your heart rate and is directly related to your respiratory sinus arrhythmia (RSA) (Thompson et al, 2015). The RSA is a natural variation in heart rate that occurs during breathing.

During inhalation, the vagus nerve lets up on the SA node, heart rate increases slightly and you will have a more sympathetic influence on your nervous system.  During exhalation, the vagus nerve acts like a brake on the SA node, heart rate decreases, and you will have more parasympathetic influence on your nervous system. (Porges 1995, Dana 2020).

Cliff notes:

  • Inhale = heart rate increases , sympathetic influence
  • Exhale = heart rate decreases , parasympathetic influence

Manipulation of your inhale and exhale will inherently manipulate your heart rate. When your heart rate changes your body and mind change with it. The mind and body do not operate separately. If we manipulate one, we manipulate the other.

In addition to the vagus nerve and SA node, nerves from both your sympathetic and parasympathetic nervous system innervate and cover your airways and lungs (Mazzone and Canning, 2013).  It has been shown that many of the nerves that are a part of your parasympathetic system are located in the lower half of your lung lobes while more sympathetic nerves cover the top half of your lobes (Nestor, 2020). 

Again, much talk around breath work is that it is “calming” and “soothing” because of this link to the parasympathetic nervous system state.

I want to be very clear about something: Science, research and data do not dictate an individuals lived experience. In particular, none of these things dictate ones sense of “safety” in any contemplative or somatic practice. We can honor the “science” and data on slow/deep breathing while respecting and honoring that no science will ever define safety for an individual.


Why can breath work be challenging?

Breath work, at any level, is both a mindfulness and somatic (body based) practice. Mindfulness and somatic practices can at times pose challenges for people, especially people who have lived through trauma. (In Part One, we define trauma and see that the prevalence of trauma in our society is actually very high).

As mentioned above, for many simply feeling their breath or manipulating it in any way can feel very uncomfortable, unsafe and unsettling.  David Treleaven , in his book Trauma Sensitive Mindfulness, states “when we ask someone with trauma to pay close, sustained attention to their internal world, we invite them into contact with traumatic stimuli – thoughts, images, memories, and physical sensations that may relate to a traumatic event.” (page 6).

Any breath work practice, regardless of its intention, has the ability to increase or exacerbate any of these symptoms which can often feel MORE activating (connected to that more sympathetic nervous system state).  This is why we cannot generically prescribe or claim that breath work is “calming”, “grounding”, or “safe”. For many people tuning in to the breath or manipulating the breath at any level feels the opposite.

If you have experienced (or are experiencing) trauma, post traumatic stress or heightened levels of anxiety or panic and breath work has been difficult for you, I want you to know that you are not alone. This makes complete sense. If a breath work practice elicits any uncomfortable feelings, difficult memories or flashbacks, hypervigilance or a feeling of not being “okay”, remember that YOU are in charge. Breath work should never be forced. You are in control to stop the practice at any time.

Many people who haven’t experienced “trauma” can/do still experience challenges with breath work.   These experiences are real, valid and deserve a safer and more accessible approach. As mentioned in Part One, I’ve had SO many athletes approach me with challenges around breath work. These challenges include increased activation, agitation, anxiousness, overwhelm, feeling flooded or feeling like they are losing control. This makes A LOT of sense given the intimate connection between our breath and nervous system. We as a society are very focused (and prioritize) intellect, rationale and reason. We prioritize living our lives “in our heads” which often leaves us disconnected from the felt sense of our body.  Tuning in to our body and the process of breathing can be challenging for people even if you haven’t experienced trauma.

There is a difference between breath work being challenging and difficult because its new or we can’t focus at times, and evoking or exacerbating harmful symptoms. Babette Rothschild (2010) shares that any work specifically concerning trauma must be to relieve not intensify suffering. But I believe this is a principle to be applied to all teaching and coaching around mindfulness and somatic practice. To coach or teach breath work in a way that is trauma aware or informed benefits everyone.

If your practice is causing you MORE harm than support its time to pivot or make adjustments. This is why I am a huge advocate of working with a licensed or qualified professional. Its always a great rule of thumb to consult with your mental health or medical provider.


Manipulation of the Breath

Too often breath work is prescribed generically and cued without respecting the individual and nuanced experience. The above section highlights WHY breath work can be so challenging and this is important to recognize as we teach and coach breath manipulation.

As you have read, when we manipulate the breath we are manipulating our nervous system. Your nervous system is intimately connected to how you think, feel and behave as well as our sense of survival. When we manipulate our nervous system we are manipulating all of these. This can be powerful and profound in both positive and negative ways if we don’t have awareness of this.

When we are in highly activated or distressful states (think panic or heightened anxiety) we are going to be in a more sympathetic nervous system state. Ideally, in this state the goal (in order to help ourselves navigate these experiences both mind and body) is to gently and compassionately  “downregulate” our nervous system. Downregulating means shifting from a more sympathetic (activated, mobilized state) to a more ventral vagal PNS state (rest, digest, safety). The breath is ONE way that we can help ourselves out, but not THE only way.

For many people, the breath does NOT feel like a safe and accessible way to downregulate their system (especially if they had trauma that impacted their ability to breathe).  So if we generically prescribe breath work as a way to downregulate and move towards safety and calm we are failing people. We also increase the likelihood of more dysregulation and shame for these clients. They need OTHER tools to help them do this and this is why accessibility and choice are paramount in our practice.

Another example is that if we have a client that is already in a shut down state (what we call a Dorsal Vagal PNS state) and generically prescribe or cue for them to “breathe deeply” there is the potential to shut them down even MORE. This is counterintuitive and can be more harmful than anything given where they are in their nervous system.

This is why I feel we should prioritize awareness and befriending of the breath at its natural rhythm FIRST before we move to any manipulation so that we set people up for success. We want people to simply know themselves and where they are at first before we move in to manipulation. When we help people build the awareness first we support them in the journey to practice breath work in ways that support them rather than harm them. 

The main take away here should be that breath work is very intimately connected to each individuals nervous system and therefore intimately connected to how we think, feel and behave. We are all different people with different lived experience and different nervous systems. The goal or intent behind breath work should never be to generically prescribe practices because no two people are the same.


In Conclusion

I hope this blog has highlighted and solidified the importance of WHY we need a trauma aware and trauma informed approach when teaching and coaching breath work. I encourage you to head over to Part 3 of this series to read up on how you can get started in a safe and accessible way!

Next Up in this Series:

Part Three: Exploring Breath Work, Where to Start?



Potential contraindications for breath work

It is always a good idea to consult your primary care provider or mental health clinician before starting or engaging in breath manipulation.

If you notice any symptoms including dizziness, light headedness, nausea, or increased heart rate, please stop immediately and consult a professional.

  • Medical: Heart conditions, asthma, emphysema, bronchitis, and other breathing problems, headaches, glaucoma, and cervical disc problems, vertigo, stroke, high blood pressure and any other cardio-vascular or neurologic conditions. Please consult your medical provider before breath work.
  • Mental health and psychological: Schizophrenia, dissociative conditions, history of trauma, PTSD, anxiety or panic disorders. Please consult your medical or mental health provider before engaging in breath work.
  • If you are pregnant please consult with your physician!






Weber, K . (2018), The subtle secrets of pranayama.  Subtle Yoga Health, LLC. Teacher Training.

Ikeda, K., Kawakami, K., Onimaru, H., Okada, Y., Yokota, S., Koshiya, N., Oku, Y., Iizuka, M., & Koizumi, H. (2017). The respiratory control mechanisms in the brainstem and spinal cord: integrative views of the neuroanatomy and neurophysiology. The journal of physiological sciences : JPS, 67(1), 45–62.

 Novotny, S. and Kravitz, L. (2017). The science of breathing.

 Dr. Stephen Porges

Thompson, M., Thompson, L., and Reid-Chung, A. (2015). Combining loreta z score neurofeedback with heart rate variability. Z Score Neurofeedback Clinical Applications.  Retrieved from: , Chapter 8

Porges, S. W. (1995). Orienting in a defensive world: Mammalian modifications for our evolutionary heritage. A Polyvagal Theory. Phsycophysiology, 32 (4), 301-319

Dana, D. 2020. Polyvagal excercises for safety and connection. W.W. Norton & Company. New York, NY

Mazzone, S. B., & Canning, B. J. (2013). Autonomic neural control of the airways. Handbook of clinical neurology, 117, 215–228.

Nestor, J. 2020. Breath. Riverhead books by Penguin Random House, New York.

Treleaven, D. (2018). Trauma sensitive mindfulness. Practices for safe and transformative healing. New York, NY. WW. Norton & Company

Rothschild, B (2010). 8 keys to safe trauma recovery: take charge strategies to empower your healing. New York, NY : Norton.



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