The Main Benefits to the Nervous System
In his book The Science of Yoga: The Risks and the Rewards William J. Broad summarizes the research findings to date on the benefits of yoga on the nervous system. In this blog post, I’m going to talk about the two main benefits to the nervous system:
- Alternating Sympathetic and Parasympathetic Activation
- Vagus Nerve Stimulation
Alternating Sympathetic and Parasympathetic Activation
One of the important findings is that yoga helps to regulate ANS by activating both sympathetic and parasympathetic arousal in a specific way using a specific sequence of poses. This process takes the nervous system and body through repeated cycles of activated sympathetic arousal followed by parasympathetic calming and settling, which is the way our nervous system was designed to operate. A well-designed yoga practice has a rhythm to it that mimics the natural rhythm of these activation-settling cycles that our autonomic nervous system tends to follow.
When we get stressed and our sympathetic nervous system is activated in an ongoing, continuous, or chronic way such that the parasympathetic calming and settling down-cycle does not happen or does not happen to the extent it needs to in order to de-activate the effects of prolonged sympathetic arousal. Worse is when the prolonged sympathetic arousal leads to a re-organization of the nervous system such that being stuck in a high level of sympathetic arousal becomes the new normal, making it extremely challenging for the mind and body to engage fully in a parasympathetic experience and therefore maintaining this high level of sympathetic arousal, often leading to greater health problems.
Practicing yoga regularly over time, especially in a group environment, gently invites the nervous system to shift out of patterns of chronic stress back into the body’s more natural rhythm of activation and settling. Repeatedly immersing the nervous system to a sequence of poses designed to mimic the body’s natural rhythm is a powerful tool for healing. Because we are wired to feel and sense what is happening not just within us but around us, practicing these activation-settling cycles in a small space with others in an organized way, ie, a teacher-led yoga class, you perhaps give our bodies an even greater opportunity to fall back into its natural sympathetic-parasympathetic rhythm.
There is a tremendous amount of research that has come out over the past decade or two demonstrating that yoga is helpful for all kinds of physical and psychological issues, problems, and illnesses. Yoga is good for both managing the stress of living with and promoting healing from a chronic health problem.
Vagus Nerve Stimulation
The other key way yoga benefits the nervous system relates to the vagus nerve. The vagus, or wandering, nerve, is the body’s 10th cranial (emanating from the brain) that connects the brain to the enteric nervous system, allowing nerve signals to be transmitted back and forth between the brain and gut. The vagus nerve also connects the brain to most of your most vital organs: “lungs, heart, stomach, liver, spleen, colon, and other parts of the abdomen.” (pg 42) The vagus nerve is involved in “the regulation and slowing of the human heartbeat” (pg 42) and has been found to have “remarkable control over the body’s immune system, playing major roles, for instance, in fighting inflammation” (pg 42).
The bottom line is that the vagus nerve is heavily involved in ANS regulation. Through your behavior, you have the ability to stimulate your vagus nerve in ways that facilitate greater ANS regulation and healing. There are many ways to do that, and I will present those in a future post. Yoga just happens to be one of the better ways to stimulate the vagus nerve because of its accessibility and the wealth of other health benefits that yoga simultaneously offers.
Yoga tends to focus on breath. Breathing consciously stimulates the vagus nerve. Stimulating the vagus nerve regularly and repeatedly in the way yoga does, particularly with sound promotes healing. Chanting “Ohm”, something that many yoga teachers incorporate into their classes, can seem awkward or strange and may not be something you feel moved to do, yet can quickly disrupt patterns of communication between the mind and gut or other organs that are generating and/or perpetuating chronic health problems like Irritable Bowel Syndrome (IBS).
Yoga a Healing Practice for All, Chronic Health Problems or Not
If you have any kind of chronic health problem like IBS, some other form of chronic gastrointestinal problem, heart problems, nervous-system dysregulation problems, endocrine problems, or any kind of problems involving inflammation, understanding the role of the vagus nerve and how to stimulate it in ways that promote healing is very important. You can learn more about the vagus nerve and the benefits of yoga here: http://sequencewiz.org/2015/11/18/vital-vagus-what-is-the-vagus-nerve-and-what-does-it-do/.
Whether or not you have a functional medical problem, doing yoga at least once a week seems like a sensible thing to do. And it makes you feel good. But as is true for most things in life, be smart in how you go about finding a regular yoga class and teacher and how you do your yoga. Yoga, like any other physical activity, can injure the body when practiced without proper instruction, guidance, and supervision. More about this in a future blog post.