Yoga and the Vagus Nerve: How to quell fight/flight response through mind-body activation.

Yoga has been close to my heart since I moved to Vancouver at the age of 17 and my sister-in-law introduced me to the Semperviva studio on Yew and 4th Avenue. Throughout my undergrad schooling, I attended yoga classes regularly as a coping method for the stress of university and the trials and tribulations of young adulthood. After giving birth to my son at the age of 23 and suffering from an identity crisis, yoga was one of the only things that helped me remember who I was again. In 2019, after about 5 years of working within the federal correctional system, I decided to take a 200-hour yoga teacher training program with Semperviva Yoga in the beautiful Kitsilano neighbourhood of Vancouver, British Columbia.

Now, 6 years later, I have yet to teach a proper yoga class. However, I continue to be immensely grateful for my yoga teacher training because it has helped me to understand why it feels so GOOD to practice yoga! In this blog post, I hope to share helpful insight on how to calm your nervous system through bringing together what I’ve learned from my personal yoga practice, my formal yoga teacher training, and my recent Master’s level education on psychology and clinical counselling.

Nervous System Activation (Flight or Flight): Why does it happen?

Most people have heard of the human response to either fight or flight in times of danger. There have now been additional responses included in this adage, such as freeze and fawn. To understand these reactions, we can start by examining what happens in our brain.

When we sense sudden danger, such as a grizzly bear running towards us, our physiology takes over to prioritize our survival. With a command from our hypothalamus, our sympathetic nervous system generates a sudden rush of adrenaline and cortisol (activation of the hypothalamic-pituitary axis – HPA), and our brain responds by focusing our energy on our amygdala (ancient lizard brain – survival mechanism), pulling all resources from our prefrontal cortex (more evolved, critical thinking area). Once the threat has dissipated, our parasympathetic nervous system (rest and digest) kicks in to bring us back to a state of balance by releasing relaxing hormones such as oxytocin.

When people experience a traumatic event and are not able to fully process the experience, reminders of the event such as smells or sounds can alert their hypothalamus to activate the sympathetic nervous system, sending them into fight or flight mode when there is no real danger or threat. This type of unhelpful sympathetic nervous system activation is often diagnosed as Post-Traumatic Stress Disorder (PTSD).

How to manually activate rest and digest mode

Experiencing post-traumatic triggers and activation can be incredibly frustrating and sometimes debilitating. While we can appreciate that our body is taking our survival seriously, having our prefrontal cortex switched off on the regular when there is no good reason for it can seriously interfere with our emotional balance and ability to exist with others! Luckily, there are things we can do to manually activate our parasympathetic nervous system (rest and digest).

The Vagus Nerve is a nerve that runs through our body to our brain. It is responsible for sending signals to our brain to release oxytocin and activate rest and digest mode (parasympathetic nervous system). In a very neat turn of events, the more-nerdy of the humans have discovered how we can directly communicate with our Vagus Nerve to reduce our stress response on demand! The most often talked about method of Vagus Nerve communication is through deep breathing. In my yoga teacher training, we learned how to take a proper deep breath, starting with mindfully filling your lungs from their very bottom, near your belly button. A full, deep breath to stimulate the Vagus Nerve can take between 8 – 12 seconds, and is most effective with a 3- 4 second pause at the top and bottom of the breath.

In Yogic teachings, breathwork such as I’ve described above is referred to as pranayama. Contrary to commonly held beliefs about yoga in the Western world, pranayama is the core of yoga, not muscle or joint flexibility. The true purpose of the yoga postures is to support your body with inhaling deep breathes in coordination with movement. This connection between breathing and moving facilitates mind-body connection, supporting communication with the Vagus Nerve.

Nerding out on Yoga for Mental Wellness (and more)

Over the past 5-10 years, yoga has received increased (Western) empirical attention as an alternative or supplement to traditional talk-therapies for mental health issues such as anxiety, depression and PTSD.  Yoga is unique as it activates both top-down (cognitive) and bottom-up (physiological) processes of parasympathetic nervous system activation. Cognitive Behavioural Therapy has been the gold-standard for treating PTSD for decades, however it has limited efficacy if someone’s prefrontal cortex is routinely compromised by post-traumatic triggers. Yoga provides an alternative, where a state of peace and calm can be achieved through breathing and mindfully stretching and strengthening muscles when thinking your way out of a stressful situation feels impossible.

So, the next time you practice yoga, I encourage you to set the intention of focusing on coordinating your breath with your movement. Move slowly, to facilitate full inhales and exhales. In the coming weeks, I will be posting some beginner-friendly yoga routines that I use to stimulate my Vagus Nerve and connect my mind with my body.