Free The Tibetan Yoga of Breath: Breathing Practices for Healing the Body and Cultivating Wisdom by Anyen Rinpoche, Allison Choying Zangmo Page A

us? As we discussed previously, by breathing abdominally, we increase the oxygen available in the blood, and therefore the brain. But also, when we breathe deeply with prolonged nasal exhalation, this action enables the vagus nerve to reset itself. 16 The vagus nerve is an aspect of our nervous system that brings equilibrium and balance to the whole. It either stimulates or calms the system, depending on what is needed. Therefore, working with wind energy training actually delivers the necessary antidote to everyone, no matter what type of stress imbalance we suffer from, despite differences in our state of mind and physical health.
    I MBALANCE AND THE N ERVOUS S YSTEM
     
    Drawing a line between stress and anxiety can be difficult. From the point of view of the five elements, anxiety is merely a stronger expression of stress. It is also challenging to find the line between anxiety and depression, as the two frequently occur together.That is why it makes sense to think of the root of all of these disorders as having a common denominator: elemental imbalance .
    While Tibetan philosophy describes this common denominator as relating to the elements, Western medicine describes it as an imbalance in our autonomic nervous system. 17 We have already learned that the autonomic nervous system is made up of the complementary interaction of the sympathetic and parasympathetic responses. However, we can add one more component to this to help us understand how the body reacts to different and more extreme forms of stress: heart rate variability (HRV) . HRV is an important indicator of both our mental and our physical health.
    HRV refers to the variation in our heart rate in response to many different things—emotions and stress; physiological factors such as hormones; and breathing. HRV is part of a feedback loop connecting the heart and brain through the nervous system. A greater variability in HRV points to good health, while decreased variability in HRV is associated with a number of unhealthy states. Even the core mechanisms of the body, such as heart rate, need to be able to adapt to a variety of conditions. As we discussed in the context of movement and energy, stagnation, or a lack of variability, is unhealthy. A lack of variability points to a habitual cycle, reaction, or behavior that may or may not be appropriate under the circumstances. In our own lives, we recognize that a failure to adapt to new circumstances usually brings us mental and emotional suffering, and even illness.
    What does HRV have to do with anxiety and depression? Both depression and anxiety are associated with low HRV. 18 This means that both anxiety and depression are characterized by an inflexible and unbalanced autonomic nervous system. The rebalancing of the sympathetic and parasympathetic nervous systems, which happens each time a healthy individual breathes abdominally, is disrupted. When a healthy person inhales, HRV increases, as the sympathetic nervous system is activated. With exhalation, HRV decreases, due to activation of the parasympathetic nervoussystem. The sympathetic and parasympathetic systems are actually self-regulating, constantly bringing themselves back into balance.
    When we are anxious or depressed, our heart rate has trouble adapting to the constantly changing environment around us. This means that the nervous system, which ordinarily functions dynamically, becomes stuck in a pattern. Through conscious awareness of our breathing, we are able to stimulate the aspect of our nervous system that is underactivated in both anxiety and depression: the parasympathetic nervous system. We are able to elicit a relaxation response through elongating our exhalation. Proper abdominal breathing, accompanied by exhalation through the nose, supports a healthy balance in our bodily systems.
    HRV and the Breath
     
    Frequent shallow breathing, or thoracic breathing, and breathing through the mouth both consistently stimulate the sympathetic