The sympathetic nervous system (SNS) prepares the body for intense physical activity and is often referred to as the fight-or-flight response. The parasympathetic nervous system (PNS) has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.
Today’s modern lifestyle promotes living a sympathic lifestyle. Sympathetic is not always bad for it prepares the body to handle sudden stress in times of need. However, unlike our ancestors we cannot always use this sudden rise in stress chemicals in its intended manner for life and death struggles. For example if we are our sympathetic system may kick in during a traffic jam. We cannot just use physical activities to decrease the chemicals but instead our stuck sitting in a car.
One way of developing a more PNS in times of stress is focusing on the breath. Focusing on diaphragmatic breathing enables us to down regulate the sympathetic nervous system, which then causes the parasympathetic nervous system to become dominant. Shallow breathing, breath holding and hyper-ventilating triggers the sympathetic nervous system, in a “fight or flight” response.
The vegus nerver is the largest cranial nerve and controls all major bodily functions including the breath, heart rate and digestion. A person’s vagal tone determines how fast they recover from a fight or flight situation. A person with a high vagal tone is more resilient to stress. People with low vagal tone, on the other hand, are more sensitive to stress and disease. They tend to have challenges such as weak digestion, increased heart rate, and difficulty managing emotions. Interestingly, low vagal tone is correlated with health conditions such as depression, anxiety, chronic pain.
The most immediate way to change the balance of sympathetic and parasympathetic nervous system actions is with the breath. To counterbalance any over-stimulation of the sympathetic nervous system, vagus nerve yoga focuses on diaphragmatic breathing and extending the length of the exhale. More to come.