Parasympathetic Nervous System Activating Technique
Maybe you've heard how a cold shower can wake you up or even help your recovery after a heavy workout. Cold-water immersion (CWI) has swept the world of social media and much of it due to its promotion by Wim Hof and his seemingly extreme combination of breathing and cold therapy. But what has science shown to be the real benefits of exposure to extremely cold water other than just saving hot water in the shower?
Read "The Stress Response: Everything You Need To Know" for more details on the physiology of the stress response and why it is important to understand.
Read "Best Practices to Build Stress Resilience" for more details on building stress resilience.
For those seeking to build stress resilience, one of the best practices is to employ evidence-based balance strategies that take advantage of your physiology. The sympathetic nervous system mediates the physiologic fight-or-flight stress response. To recover from stress, the parasympathetic nervous system (PSNS) is activated. It is what brings you back to a recovered or balanced state. Activating the PSNS through physiologic mechanisms is one way to help you reduce stress by building stress resilience. It does so by reducing your exposure to unhealthy levels or extended time periods to cortisol and adrenaline. Cold-water immersion is one such physiologic tactic to activate the parasympathetic nervous system.
Evidence has shown that repeated dips into cold water (12º C/54º F) over a period of time will reduce the amount of adrenaline released when exposed to a different stressor. This reduction in sympathetic activity lowers the stress response while increasing parasympathetic activity which heightens the recovery response. To cope with the stress of cold temperatures, your body adapts by becoming better able to cope with not just future cold exposure, but also other unrelated stresses as well. Your body becomes "habituated" to dealing with stress and when done appropriately this controlled exposure can down-regulate your stress response and up-regulate your recovery ability. This happens with future cold exposure, but also you will develop the ability to recover or calm down from other stresses as well. We call this cross-adaptation.
What Are the Potential Health Benefits of Cold-water Immersion?
▹ Pain reduction
Increases local anesthetic effects
Increases dopamine concentration (low dopamine is associated with pain syndromes)
Decreases nerve conduction
Blocks pain stimuli receptors
Increases pain tolerance
Decreases muscle soreness
▹ Improved Circulation
Can help lower blood pressure (hypertension) by up to 11%
Improves blood flow
▹ Stimulates Weight Loss
Increases metabolic rate
Improves brown fat, aka the good fat, activity (has been shown to potentially help lose up to 9 pounds a year)
▹ Decreases Fatigue
Increases muscle recovery rate
Decreases lactate concentration after a workout
Decreases the perception of fatigue
▹ Decreases Stress
Increases tolerance to stress
Can lower cortisol (stress hormone) by up to 34%
Can lower adrenaline levels
Can decrease sympathetic response and increase parasympathetic response
▹ Improves Mental State
Increases anti-depressant effects
Can have anti-psychotic effects
▹ Improves Immune System
29% reduction of self-reported sick leave from work
Increases leukocytes, granulocytes, circulating levels of interleukin (IL)-6, and natural killer cells (all are immune positive stimulating effects)
Increases both in numbers and activity of peripheral cytotoxic T-lymphocytes and NK cells (the major effectors of adaptive and innate tumor immunity)
▹ Improves Hair and Skin
Tightens cuticles and pores (this prevents them from getting clogged)
Prevents the skin from being stripped of its natural oils
▹ Increases Testosterone Production (in men)
How to Incorporate Cold-water Immersion Into Your Routine?
The key to increasing the recovery effect of the parasympathetic nervous system is cold exposure and not necessarily full water immersion. One study showed increased parasympathetic activity by drinking ice water and another showed that cold stimulation to certain parts of the neck had similar effects. Practically speaking, a cold shower is the easiest way to build a cold exposure habit into your daily routine. Whatever method you choose, here are a few tips to help you get started.
Tips to help you get started
Start with your normal shower (usually around 100-105º Fahrenheit)
Gradually decrease the temperature of the water to decrease the shock
The ideal cold shower temperature is 50-59º Fahrenheit
You do not need to get your head or hair wet for this to work
Shoot for 2-3 minutes minimum duration of cold exposure, but up to 5 minutes is ideal
Now that you have some knowledge about how to build better stress resilience, turn that knowledge into power and do something. Ask yourself:
"What can I do? What is one thing that I can control that will make a difference in my life?"
If you are familiar with the Meducos Method, you’ll know that by taking just one small intentional step and through daily practice you can make enormous changes in your life.
Start small to end big.
To make it easier for you to track your progress and to keep yourself accountable, you can download a Personal Intention Record from the Meducos Healthy Tactics and Tools page. Or you can download it directly from here:
Now that you have some knowledge, turn that knowledge into power to change your life and the lives of those around you. Sharing what you learn with others is an integral part of the learning process so now that you are on your way to making lifestyle the best medicine in your life, go share what you’re learning with someone else, and together we can #SpreadHealth.
For information on how to build stress resilience, see the Building Stress Resilience page on this site.