Guest post by kids’ yoga teacher Colleen Cash
Picture this: You’re zipping down the road, singing along with your favorite tune, when a car cuts you off. In that split second, how does your body respond?


In both of these situations, the body’s response is guided by the autonomic nervous system – the aspect of the peripheral nervous system that’s outside our voluntary control. In the first case – an emergency stress response (a/k/a “fight or flight”) – it’s the sympathetic nervous system (SNS) at work. The relaxation response, in turn, is coordinated by the parasympathetic nervous system (PNS).
Why should teachers and parents care? The autonomic nervous system determines how a person’s whole being functions. Once we understand how it works, we can better read and respond to the kids in our lives. Further, yoga offers a way of balancing the sympathetic and parasympathetic nervous systems – an especially important task in this day and age of near-constant stress.
Why We Need a Stress Response
While most people assume that stress is always a negative thing, our bodies require an emergency setting. Our ancestors certainly needed a way to quickly respond to terrifying situations.
The deep intelligence of the body is revealed in how every system shifts its functioning under stress. Put yourself in your prehistoric forebear’s shoes. You’re minding your own business, gathering fibrous roots, when you hear a branch snap under the paw of a huge saber-toothed cat, stalking you for its dinner. Within milliseconds, your body shifts to the sympathetic response so you can respond appropriately to the danger:
- The pupils dilate, to better see the threat.
- The heart speeds up to send more blood to the limbs, in case you need to run away.
- The liver releases more glucose, for ready energy.
- Muscles tighten, preparing to flee or fight.
- Digestion, immunity and salivation are inhibited, as these functions aren’t needed right away.
- The brain’s planning center and most advanced part, the prefrontal cortex goes offline, while the more primitive parts, including the emotional limbic system, take over.

The parasympathetic mode is like the brake pedal. It’s the mode we natural shift back into once the threatening situation is past. The pupils constrict. The heart rate decreases. The muscles relax. Offline systems come back online. It’s a time for repairing cell damage and boosting immunity and other restorative functions.
How Stress Gets the Better of Us
These systems evolved millions of years ago, when early humans faced threats rarely. However, we now live in an era of near-constant stress – only now, it’s not saber-toothed tigers but things like cruel bosses, mean classmates, looming deadlines, eternally full inboxes. Logically, we know such things are nowhere near as hazardous as a hungry predator. Physically, we respond otherwise.
The result? A great many of us get stuck in the sympathetic stress response – a state that plays a key role in many of the chronic, non-communicable diseases that accompany our modern lifestyle. For instance, as Daniel Lieberman discusses in his exceptional book The Story of the Human Body,
- Heart disease can stem from prolonged stress, as SNS activation causes cardiac inflammation and elevated levels of damaging stress hormones.
- Type 2 diabetes stems from a lack of sensitivity to insulin, the chemical that causes our organs to pull glucose out of the blood stream. While the mechanisms of diabetes onset are not deeply understood, scientists do understand that stress dumps glucose into the blood stream, as the SNS ramps up. Along with sugary diets, chronic sympathetic activation may contribute to the development of type 2 diabetes.
How Yoga Can Shift Us from Stress to Rest
Fortunately, we can use yoga to notice and soothe the stress response. Our breath, for instance, is a powerful tool for changing our physiological state. The breath is both autonomic and within our control. Our body shifts how we´re breathing in response to our experiences. But we can also change how we experience the world by shifting our breath.

Yoga also teaches us how to notice our own internal states, to develop body awareness. Just noticing the stress response is a huge triumph. With enough practice, we can begin to label our experiences without taking them personally or getting overwhelmed by them.
The next time someone cuts you off in traffic or an unexpected event sends your kid into a stress response, practice taking five deep breaths. Just five deep breaths can be enough to shift the body and mind from the sympathetic to the parasympathetic response—and from stress to calm.

Top three images by mob mob,
Exotissimo Travel & frankieleon, via Flickr




