Exercise and the Autonomic Nervous System
Regular exercise can help improve mood, regulate emotion, and increase our capacity to cope with change at a physiological level. These benefits stem largely from movement’s effects on the autonomic nervous system.
The autonomic nervous system regulates the critical, unconscious functions of the human body, such as breathing, digestion, heart rate, and more. Two of its branches are the sympathetic and parasympathetic nervous systems, which work in tandem to promote homeostasis.
Stressful events trigger the sympathetic nervous system. The body calls upon its antagonist, the parasympathetic nervous system, once the stress has passed to allow for ease and relaxation. Exercise has been shown to improve parasympathetic nervous system functioning, which is important if one wants to maintain a solid baseline of physical and emotional well being.
Read on to learn more about the autonomic nervous system and how working out can significantly improve your ability to recover from the stressors of everyday life!
Sympathetic Nervous System
The sympathetic nervous system manages the “fight or flight” response in the body. It is activated by dangerous or stressful situations and puts the body on alert. Common physiological responses include (but are not limited to) quickened heart rate and breathing, dilated pupils, slower digestion, and increased muscular tension.
The sympathetic nervous system can be triggered by many of life’s modern stressors, even if the situation at hand is not actually life threatening. For instance, an anxiety-inducing situation at work can provoke the amygdala (which is associated with fear and emotions) to transmit a message of danger to the hypothalamus, resulting in the adrenal glands flooding the bloodstream with adrenaline. It is possible to develop an overactive sympathetic nervous system if one experiences prolonged periods of emotional upheaval and stress without the tools required to enter a more relaxed state.
An overly active sympathetic nervous system is not just related to impaired ability to regulate emotions, it is also associated with increased risk of stroke and heart attack.
This is why it’s important to maintain a well-functioning parasympathetic nervous system, which works to stabilize and calm the body when the perceived threat has passed.
Parasympathetic Nervous System
The parasympathetic nervous system is responsible for the “rest and digest” aspects of the autonomic nervous system, and returns the body to a relaxed state after an emergency or stressful situation has passed, in part by sending messages through the vagus nerve that the danger is over. It’s responsible for stabilizing the system, and it does this in multiple capacities, like decreasing heart rate, slowing breathing, and allowing for proper digestion.
The Vagus Nerve and Heart Rate Variability
The vagus nerve is the largest nerve of the parasympathetic nervous system. “Vagus” (pronounced “Vegas”) comes from the latin word for “wandering”. Originating in the brain, this nerve travels throughout the body (including the face, neck, heart, and gut), makes up ¾ of nerve tissue within the parasympathetic nervous system, and connects to all major organs.
Considering the vast importance of the vagus nerve on our overall physical and mental well being, researchers have undertaken efforts to measure means of improving its health and strength. One way of assessing vagal activity is measuring heart rate variability.
Heart Rate Variability (HRV) measures the amount of time that occurs between heartbeats. Higher HRV means more variance in the time between heartbeats, indicating one’s ability to respond to different stimuli. When the parasympathetic nervous system is stimulated, HRV increases. Conversely, when the sympathetic nervous system is active, HRV decreases. However, if an individual is in a state of chronic stress or overload, the sympathetic nervous system may become overactive, resulting in increased stress hormone levels and a lower HRV.
It is imperative for one’s mental and physical health to train the body to return the body to a relaxed state by strengthening vagal nerve activity, increasing HRV, and allowing for balance between both branches of the autonomic nervous system.
Exercise and the Parasympathetic Nervous System
Exercise, such as resistance training and yoga, has been shown to positively affect parasympathetic nervous system functioning through an increase in vagal tone and heart rate variability.
In one study, vagus nerve activity was measured during exercise for one group and at rest for another. The group participating in moderate movement displayed a significant increase in vagal activity when compared to the resting control group. Additionally, authors of the study stated that it’s likely interval training also promotes improved vagal activity.
A 2016 review of 59 studies with a total of 2358 participants found that yoga impacts cardiac autonomic function, showing an increase in heart rate variability during practice, as well as increase in vagal tone both during and after. These findings suggest the strengthening of a mind/body connection through yoga (and all forms of movement that call upon practitioners to focus on their breath) is quite literal.
Improved autonomic nervous system function helps all to feel more emotionally balanced as it enhances our ability to adapt to different stressors throughout the day. Not only that, yoga actually slows the decline of aging in the brain and utilizes our brain’s elasticity to enable it to develop more positive emotions and feelings of ease.
The effects of endurance training and autonomic function have also been studied extensively, again demonstrating exercise’s ability to decrease sympathetic activity and increase parasympathetic activity in the heart. Physiologically, aging leads to a decrease in parasympathetic activity in the heart is common, so finding ways to mitigate this decline is crucial to feeling well in our later years.
While many turn to exercise as a way to alter their physical appearance, it has the potential to do so much more for us on a much deeper level.
Come into GOODFORM to start or continue your fitness journey and feel these benefits for yourself!
