Breath Awareness Part 1: The Science of the Breath

How do I develop an awareness of my breath?

I am so glad you asked! Why? Because breath awareness is the cornerstone of a beneficial yoga practice (and by “yoga” I mean the physical practice of asanas, the breathing practices associated with pranayama, and the ability to meditate – dhyana– among others). 

It took me years to realize that the breath guides the pose, not the other way around. 

Let’s drift back to 2010 when I’d discovered Ashtanga Yoga. This is a system devised by the late Sri K Patthabi Jois and is continued currently by his grandson Sharath Jois in Mysore, India. It is six series, each series an established set of asana. A practitioner begins with the Primary series, gradually learning this series over months or years before progressing on to the Intermediate series. Following that are four Advanced series. 

So, there I am in 2010 falling for the misguided belief, as so many do, that “Primary” equates with “Beginner” or “easy”. I huff and puff my way through a grueling 90-minute practice that has me completely out of breath for the last 75 of those minutes. I started the practice with my hair in a plait, my drawstring yoga shorts in place, and a level of anticipation that if verbalized would translate to “squeeeeee”. I had been looking forward to starting Ashtanga for a while. Fast forward an hour and a half and my plait was more reminiscent of an electrocuted hedgehog, the drawstrings had retreated into the elastic of my shorts never to be retrieved again, and my anticipation was replaced with the sour taste of defeat. I could not understand how the people in the video looked so relaxed throughout. The instructor was explaining how savasana was there to integrate all the hard work, so not to skip it. Who skips this? How do you skip lying down after all that torture?? Who has the energy to think “You know what, I really need to spring into action now”? 

This scene happened frequently throughout my Ashtanga life, and still does, if I am being totally honest. I am more suited for half-primary, which I later found out was a thing, after giving myself several injuries. Why? Because it gives me time to focus on the quality of my breath, over “am I in the deepest expression of the pose like I feel I should be?”. 

When I have a practice that is focused on the breath, not so much the pose, I leave that practice feeling so much more rejuvenated and ready for the day than when I focus on how to (or, more likely, why I can’t) do a pose. 

If you’re out of breath during an asana class, pull back, take Child’s Pose (Balasana), and return when your breath has normalized. Huffing and puffing your way through class is not the intended purpose. Focus on a smooth inhale and exhale, even if that means taking more breaths than is cued by the teacher, or going slower than the teacher demonstrates. This will ensure you get the physiological benefits of the practice.

Why is the breath so important in yoga?

To understand this, we need to get a bit sciency. 

We need to zoom in on our Parasympathetic Nervous System (our rest and digest system) and our Sympathetic Nervous System (fight-or-flight). These are both components of our Autonomic Nervous System, responsible for all the processes in our body that we don’t voluntarily control (like heart rate, and digestion). 

The Autonomic Nervous System and The Window of Tolerance

When we are faced with a threat, our Sympathetic Nervous System (SNS) kicks in, reducing energy to non-vital processes such as digestion, and redirecting it to processes necessary for immediate survival, such as increased heart and breath rates, pupil dilation, and blood flow to the muscles preparing them for action (Lutz, 2021; McGonigle & Huy, 2022). In essence, preparing us to fight or flee. The ancient yogis called this rajas. In this state, we feel anything from nervousness, anxiety, frustration, and panic, to anger, rage, and over-excitement. Our breath is shallow and quick, our heart rate is higher than normal. 

When the threat dissipates, the Parasympathetic Nervous System (PNS) kicks in, bringing us into our Window of Tolerance (Siegel, 1999), which is where we feel relaxed yet sufficiently alert, where we respond appropriately to the normal stresses of the day, and where we feel ready to be socially engaged. The yogis called this sattva. We will be breathing normally, inhaling and exhaling through the nose, with deep, long breaths. Our heart rate is normal, with some variability as it increases on the inhale (activating the SNS), and decreasing on the exhale (activating the PNS)

If, however, the body detects that fight or flight is not possible, and the threat is not dissipating, the Parasympathetic Nervous System can bypass the Window of Tolerance and apply the emergency brake, what we now refer to as a “freeze” response, and what yogis called tamas. In this state, we may feel immobile, lethargic, and depressed, and we may experience brain fog, disconnection, and dissociation (Danylchuck, 2019; Lutz, 2021). 

Figure 1 

The Autonomic Nervous System and the Window of Tolerance

(adapted from Siegel, 1999)

How does the breath help?

If we are exposed to consistent threat or stress, then we can get stuck in “on” mode (the SNS is persistently activated), in “off” mode (where we stay in a “freeze” response”), or, as is often the case, swing wildly between the two trying to find some sense of equilibrium. This can feel very scary and confusing and is often not that easy to articulate to others as we don’t really understand what is going on or how to stop it. 

This is where the breath comes in. When we are in fight-or-flight, our breath is shallow and rapid. You may notice this before you have to give a presentation or speak to someone about something difficult. Our SNS is activating shallow and rapid breathing to prepare us to flight or flee. If we find ourselves stuck there, or we want to find a way to calm down before the presentation or difficult chat, then one trick is to use the breath. Slowing down and deepening the breath can signal to our body that there is no threat, and activate our PNS, bringing us gradually into our Window of Tolerance. Doing this regularly, under the guidance of a trained teacher, can help to widen our Window of Tolerance and lessen the occurrence of the SNS being unnecessarily switched on. According to Hallins – Pott (2022, para 1), By regulating their breathing to 5-6 breaths per minute, a person’s heart rate is complimented to the point that the parasympathetic system is triggered and their body and mind are able to enter a more relaxed state.”

The same goes for when we are stuck in freeze mode – certain breathing techniques that are focussed on more rapid breathing can activate the SNS bringing us up into the Window of Tolerance. It all depends on what you need at the time, but most of us we operating on high-alert, therefore benefiting from practices that help to regulate deep, long inhales and exhales through the nose. (Why through the nose? More on that in Part 4 of this particular series, but I would also highly recommend reading the excellent book Breath by James Nestor to get a comprehensive understanding of the science of the breath).

In an asana practice – a class focussing mostly on the physical practice of yoga – it is hugely beneficial, therefore, to focus on the breath first. Use the practice to help develop deep, long inhales and exhales as this is what will help calm the mind and widen your Window of Tolerance. When mind and body are calm, they will work in synergy and you will find the body opens up much more, allowing you to explore poses further without all the negative self-talk, the huffing and puffing, the comparison to others in the room/on the screen, and the feeling of being frazzled in Gordan Ramsey’s frying pan at the end of class. None of that. Instead, you will feel rejuvenated, ready, calm, and grounded, and the fact that you couldn’t straighten your legs in Downward Dog (Adho Mukha Svanasana) today will not faze you so much. 

Conversely, if you are huffing and puffing in asana practice, you are more likely to be activating the SNS and therefore may find yourself feeling anxious, nervous, frustrated or worse, panicked, angry, or over-excited in class – all things we are trying to avoid. 

If you’re out of breath during an asana class, pull back, take Child’s Pose (Balasana), and return when your breath has normalized.

In next week’s post, we will be looking at how to develop breath awareness even before we get on the mat. Until then, let me know if you have any questions or comments about the breath that you want me to address. You can do this by emailing me at, or heading over to my Instagram and leaving me a comment or message there. 

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Until then, much love,



Danylchuk, L. (2019).Yoga for trauma recovery: Theory, philosophy, and practice. Routledge.

Hallings – Pott, C. (2022). The Power of Breathing with Awareness. Centre for Trauma Healing and Growth. https://www. 

Lutz., J. (2020). Trauma Healing in the Yoga Zone: A Guide for Mental Health Professionals, Yoga Therapists, and Teachers. Handspring Pub Ltd.

McGonigle, A. & Huy, M. (2022). The Physiology of Yoga: An Evidence-Based Look at How Yoga AffectsHealth and Well-being. Human Kinetics.

Siegel, D. (1999). The Developing Mind: Toward a neurobiology of interpersonal experience. Guilford Press.