How Your Breath Affects Your Nervous System

One little known fact about yogic breathing techniques concerns their profound effects on the autonomic nervous system. Extending or lengthening the exhalation is a powerful way to trigger the parasympathetic nervous system, the Rest and Digest part of our nervous system’s balancing program. In fact, our breath patterns affect the nervous system in both ways – to either balance and quiet the system or excite it. It’s worhwhile to understand how this actually happens.

How Does Your Breath Affect Your Nervous System? 

The Autonomic Nervous System (ANS) that connects brain to body is a two-way street. If I am anxious and nervous or stressed out by events in my life or simply the thoughts about those events, my brain, via the nerves of the ANS, will likely turn on the Sympathetic part of that system (the Fight or Flight response), which could result in faster heart and breathing rates, and increases in blood pressure, to mention just two of the most obvious physiological changes.

But the cool thing is that the lungs and heart can feed back to the brain and essentially convince the brain that things are calm and peaceful, even when there are still stressful circumstances. One neat way this happens involves the relationship of the heart and lungs and the nerves between them.

In each round of breath, during your inhalation, your heart gets stimulated to beat a little faster. Then during the exhalation that follows, your heart gets told to slow down a tad. The overall effect is very little change in the heart rate from minute to minute.

But when you make one part of the breath cycle, either the inhale or the exhale, longer than the other, and you do this for several minutes, the accumulated effect is that you will either slow the heart rate down or speed it up from where you started. When you make the inhales longer than the exhales, for example, by using a two-second inhale and a one-second exhale, and you keep this up for several minutes, the heart rate will go a bit faster. This will send a feedback message to the brain that things need to activate more in the brain and body for whatever work there is to be done, stimulating the Sympathetic portion of the ANS.

With the very useful Bhramari breath Timothy expanded on Bhramari Breath with Mudras, we do the opposite. As we hum during the exhalation, the exhales get longer relative to the inhales, as when we do a 1:2 ratio breath practice without the humming. This new respiratory cycle begins to slow down the heart rate, sending a message to the brain that everything is more peaceful and calm than five minutes ago, allowing the brain to support this shift further by activating the Parasympathetic portion of the ANS (the Rest and Digest or Relaxation response) that goes back from brain to body.

Research has shown that the vagus nerve as well as certain chemical neurotransmitters account for these effects of breath patterns on heart rate and subsequently on shifting the balance between the Sympathetic and Parasympathetic parts of the ANS. Keep in mind that the ANS is trying to keep all background systems in balance and responding appropriately to ever-changing circumstances of our day.

In short, our conscious choice of breathing differently can shift us to a more desirable part of the ANS, either by stimulating the active Sympathetic branch or the quieting Parasympathetic branch.  Most of us need more of the latter, but not always!

Originally Published on Yoga for Healthy Aging 
 

For more information on Yoga U courses with Dr. Baxter Bell and Dr. Timothy McCall see here:

Yoga for Digestive Health with Dr. Baxter Bell.

Yoga for High Blood Pressure – Do’s and Don’ts for Yoga Teachers with Dr. Timothy McCall

Baxter Bell, MD, is a yoga teacher and educator, physician and medical acupuncturist. These days he focuses on teaching yoga full time, both to ordinary students of all ages and physical conditions, and to the next generation of yoga teachers, to whom he teaches anatomy and yoga therapy along with his accessible, skillful style of yoga. Baxter brings a unique perspective to his teaching, combining his understanding of anatomy and medicine with his skill at instructing people from all walks of life and all levels of ability. Baxter is the co-founder and writer for the popular Yoga for Healthy Aging blog, where he shares his knowledge of medical conditions, anatomy, and yoga with practitioners and teachers across the world. In addition to being a frequent presenter at Yoga Journal Alive events and yoga conferences such as IAYT’s SYTAR, he is often quoted as an expert on yoga and health by major national news outlets such as The Washington Post and Wall Street Journal. To learn more, visit www.baxterbell.com, www.yogaforhealthyaging.blogspot.com, and his YouTube channel Baxter Bell Yoga.