When most people think of stress, they think of it as a bad thing. Feeling stressed is generally associated with a negative event or emotion. But there are actually two types of stress: distress and eustress. Distress is the negative-type stress, the characteristic feeling associated with a job loss, an argument with a friend, or an unexpected traffic jam. Eustress is that feeling during such events as a raise, a marriage, or when winning a race. All these events place stress on the body and mind, but not all are perceived as negative.

The human body has an amazing capacity for finding balance, or what is called homeostasis. The many physiologic processes in the body all have the overall intention of returning the body to homeostasis. When stress is felt, whether it’s emotional, mental, or physical, the body responds by increasing the production of stress hormones. This function falls under the direction of the autonomic nervous system, the part of the nervous system that controls the involuntary functions of the body, like heart rate, metabolism, and digestion.

The autonomic nervous system is comprised of two parts: the sympathetic and parasympathetic nervous systems. The sympathetic nervous system activates heart rate, blood flow, and the release of adrenaline. Essentially, it controls the fight-or-flight response. The fight-or-flight response is the body’s reaction to a perceived stressor. Evolutionarily, this response was essential for survival in life-or-death situations. In today’s world, the stressors we encounter are usually not life or death, but instead are encountered on a regular basis. Chronic stress, as experienced by so many people, has the effect of resetting the body’s point of homeostasis to a new, not-quite-balanced point, which has long term effects on our health, both mentally and physically.

The parasympathetic nervous system regulates calmer actions in the body, like digestion. The sympathetic and parasympathetic nervous systems work in a push-pull manner. When the sympathetic nervous system is activated, the heart speeds up, adrenaline courses through the body, and digestion is slowed. When the sympathetic nervous system calms down, the parasympathetic nervous system is activated and digestion begins again. Think about how when you get upset you lose your appetite, or get a stomach ache. These are the manifestations of the autonomic nervous system at work.

Almost no one can deny the experience of stress, at least occasionally, but more likely on a regular basis. The good news is that the perception of stress can be modified. Different people will react to the same stressors in different ways. This means that it is possible to change how you react to stress. One of the greatest ways to do this is by practicing yoga.

Yoga is well-known as a stress-reducing practice. But do you know why? For one, yoga helps to calm the sympathetic nervous system. It essentially calms the stress response. The regular breathing, calm mind, and inner peace gained by practicing yoga are the results of a quieting of the sympathetic nervous system. But that’s not all. The vigorous postures and sequences of yoga stimulate the sympathetic response creating eustress — that invigorating feeling that comes from winning a race, or from completing a strong yoga practice. Often, the yoga practice includes both stimulating and calming events that help balance the autonomic nervous response. When practiced regularly, this has the ultimate effect of helping us respond appropriately to stress.

So the next time you encounter a stressor, come to your mat the first chance you get. If you can’t get there right away, invite in some deep belly breaths. Let your mind rest on the breath, even if for a few moments, helping to prevent it from getting caught up those fluctuations of the mind. Om, shanti, shanti, shanti. Om, peace, peace, peace.