“Just take a deep breath” they say. Breathing oxygen is the essence of life, this goes without saying. Over the course of human history many have attempted to harness this essential activity to augment their physiological being. Many of us are familiar that deep breathing is a core component of such activities as yoga, Tai Chi Chuan, martial arts, and meditation. It is thought to contribute to emotional balance and social adaptation. But why and how? Here we try to help explain physiologically how breath can help restore balance. Balance that initially is physical, but has emotional effects.
Breathing practice is also known as “diaphragmatic breathing” or “deep breathing”. It is defined as an integrative body-mind exercise for dealing with stress and psychosomatic conditions (i.e depression and anxiety). This type of breathing is characterized by contraction of the diaphragm and expansion of the abdomen (your belly) to its maximum ability. This in turn deepens inhalation and exhalation to its full capacity. One takes a long deep inhalation for a few seconds, holds for a few seconds, and then exhales slowly through the mouth for a few seconds. This is done for 10-15 minutes a few times a day. By consequence our respiratory frequency decreases. This allows for maximum gas exchange, regulation of the autonomic nervous system, changes in the neuroendocrine system, regulation of the cardiopulmonary system, and changes in brain activity.
Clearly, breathing provides us with oxygen needed for survival. However, there is another important physiological consequence of breathing called ventilation. Ventilation is the regulation of carbon dioxide (CO2). CO2 is the end product of our tissues using water and oxygen. Changes in the rate we breath and the depth with which we breath, alters the clearance of this gas. In turn, this impacts the pH of our blood through a chemical called bicarbonate. Breathing fast (commonly known as hyperventilating) and your blood becomes too basic. One can feel jittery and light headed for example. Breath too slowly, and your blood can become more acidic which is tolerated by the body much better and with less consequence. Therefore, the rate and depth at which we breath is in homeostasis with our blood pH through chemical receptors in the brain.
Moreover, this has effects on the autonomic nervous system. This system of nerves helps regulate our heart rate, blood pressure, and other features of the famed “fight or flight” response. There are two contrasting (yet balancing) sets of nerves that connect our core organs (heart, lungs, blood vessels, eyes, liver, kidneys) to our brains. The sympathetic and parasympathetic. The latter being heavily engaged during times of stress and/or fright. When the sympathetic nervous system is activated a chain reaction occurs. Among others, our heart rate increases, blood vessels to our heart and muscles dilate for more oxygen and blood flow to these tissues, our eyes dilate for better vision, and our liver makes more sugar as fuel. This response is meant to flee danger. In the present day, dysfunction within this system has been linked to anxiety, PTSD, panic disorder, depression and others. Many studies have shown that deep breathing helps ignite the vagal or parasympathetic system. This is our body’s natural counterbalance to the aforementioned changes. Think slowing of the heart and decreasing blood pressure. A physiological break, and a break from fright! Many scholarly articles have noted a connection with vagal (parasympathetic) tone and emotional regulation, psychological adaptation, empathetic response, and emotional reactivity and expression. With deep breathing, we are trying to increase parasympathetic tone and decrease sympathetic tone in the autonomic nervous system.
Neuroendocrine, simply put, is the connection between this nervous system and our hormones such as insulin, thyroid hormones, etc. Chiefly studied is the hormone cortisol, a steroid hormone of the glucocorticoid class. Cortisol is released by our adrenal glands (above the kidneys) during times of stress and is associated with CO2. Cited by many scholarly articles, its release has been associated with depression, anxiety, and other negative emotions. This hormone regulates metabolism (increases glucose), increases blood pressure, alters sleep/wake cycle, immunity, and mental processing (including memories and emotional appraisal). Therefore, it has been used as a scientific marker for stress. The more cortisol detected the more stress the body is under. Many studies found that deep breathing lowers levels of this hormone, and therefore it is correlated that the body is under less stress.
If the topic is hard to follow just remember to breathe! The goal of deep breathing is to help regulate and restore your body and mind back into a state of physiological and homeostatic balance.
Neeraj Sathe DO
Board Certified Internal Medicine
Board Member, Fishing the Good Fight