Combining the Parasympathetic Nervous System and the Outdoors: A Match Made for Maximum Relaxation
written by MEDA undergraduate intern, Kellie Marie Martin
Most people can imagine a time when they felt stressed or overwhelmed. Everyday people are exposed to numerous forms of intense stimuli: careers, social media, family matters, and more. When these stressors build up, it isn’t uncommon for individuals to look for a release from their negative emotions. Knowing ways to effectively cope with stress is important for maintaining a healthy well-being. The brain also has methods to induce relaxation that we often aren’t aware of. Understanding how the brain combats stress can very effectively help (or be used as an addition to) other methods used to relieve tension fast.
When people get stressed, sometimes the brain reacts by activating its fight-or-flight response. This is controlled by the part of the brain called the sympathetic nervous system (SNS), which is one of two parts of the autonomic nervous system.1 The fight-or-flight response essentially prepares the body to handle the stressful situation by either bracing for a fight or getting ready to flee. Unfortunately, often this response is triggered by non-life-threatening situations, so it is helpful to know how to combat it. This is where the second part of the autonomic nervous system comes in, otherwise known as the parasympathetic nervous system (PSNS).2 The job of the PSNS is to regulate the body’s heart rate and stress levels so that normal bodily functions can resume, rather than be controlled by, the fight-or-flight response.3
The easiest and fastest way to activate the PSNS can be done by putting your face in cool water for approximately 30 seconds.4 This triggers the mammalian diving reflex, which changes the body’s chemistry in order to stimulate the PSNS to initiate a relaxation response.5 The brain essentially thinks it’s in a dangerous underwater situation where remaining calm is vital for survival, so it responds in a way to do just that.6 Although not required, dunking your head in water outdoors (such as in a lake or pool) can provide additional support in making you feel relaxed.
After the PSNS kicks in from the mammalian diving reflex, staying in the water provides an opportunity for gentle movement. Some options for gentle movement include swimming, kayaking, or stretching. Moving the body releases endorphins, which are hormones that help combat anger, anxiety, and sadness. Staying in the water, however, is not always an option.
Another way to activate the PSNS is by practicing yoga. When practicing yoga, the body connects to the mind through breathing techniques, holding postures, and consciously trying to relax.7 Additionally, yoga provides the opportunity for body-awareness and self-awareness. Having the time to look inward is important for maintaining a healthy well-being.
Another possibility to try is activating the PSNS while indoors, and then going outside to maintain maximum relaxation. There are numerous benefits to spending time outdoors, such as increasing vitamin D levels and improving concentration and focus.8 Healthy levels of vitamin D help combat depression, fatigue, and muscle pain as well as promoting strong bone growth.9 The easiest way to increase vitamin D levels is to be outside in the sun. So, while outside, do something enjoyable. Some options are to go on a walk or a hike, plant some flowers, or sit on a park bench. Doing something that requires attention provides the opportunity to only focus on that one thing and push out any stressors from the mind.
Practicing deep breathing outdoors is an effective option that allows you to reap the benefits of being outside as well as cueing the PSNS to kick in. Deep breathing essentially means inhaling and exhaling slowly. This can be done by counting to five as you inhale, and then again counting to five while exhaling.
The next time that you are feeling overwhelmed, consider trying these methods. Dunk your head in cool water, practice some gentle movement (preferably outdoors, but indoors works well too), try practicing yoga, and breathe slowly and deeply. Reducing stress and tension in the body does not have to be a difficult task, but one that is enjoyable instead.
 Parasympathetic Nervous System. Biology Dictionary. (2017). https://biologydictionary.net/parasympathetic-nervous-system/
4 Sevlever, Melina. Dialectical Behavior Therapy (DBT) Distress Tolerance Skills: TIPP Skills. Manhattan Psychology Group, PC (2018). https://manhattanpsychologygroup.com/dialectical-behavior-therapy- dbt-distress-tolerance-skills-tipp-skills/
7 Oijala, Leena. This is How (and Why) a Yoga Practice Strengthens Your Nervous System and Brings Balance Back to Your Body. Organic Authority (2016). http://www.organicauthority.com/this-is-how- and-why-a-yoga-practice-strengthens-your-nervous-system-and-brings-balance-back-to-your-body/
8 A prescription for better health: go alfresco. Harvard Health Publishing: Harvard Medical School (2010). https://www.health.harvard.edu/newsletter_article/a-prescription-for-better-health-go-alfresco