You may have heard about the mind-body connection: the idea that physical health and emotional or mental health are connected . The mind and the body are often treated separate, when in fact they are intertwined. Our mind and emotions can be impacted by stressful life events and relationships. Our bodies respond to this stress. Examples could include headaches, developing high blood pressure, fatigue, difficulty sleeping, irritable bowel syndrome, and many more physical responses .
The reverse is also true - what happens physically to our body also impacts our mind and mental health. Consider the well documented relationship between exercise and mood, or between nutrition, gut microbiome and mental health , . The gut has even been nicknamed the second brain by scientists, due to the network of neurons it contains . The neurotransmitter serotonin plays a key role in mood and emotional regulation, and 95% of serotonin is produced in the gut .
Consider common colloquial phrases like “trusting your gut instinct” or “going with my gut.” Our language reflects this link between the body and the mind. This connection is suggested to manifest as the communication between the gut and the brain . The communication pathway exists through the vagus nerve . The longest nerve in our body, the vagus nerve is actually a bundle of nerves that connect your brain to many important organs in the body, including the gut (intestines, stomach), heart and lungs , . It influences digestion, immune system function, and stress recovery.
The vagus nerve has implications for stress and the body’s sympathetic and parasympathetic nervous systems. As Edith Zimmerman in an article in The Cut puts it: “The vagus nerve is essentially the queen of the parasympathetic nervous system — a.k.a. the “rest and digest,” or the “chill out” one — so the more we do things that “stimulate” or activate it, like deep breathing, the more we banish the effects of the sympathetic nervous system — a.k.a. the “fight or flight,” or the “do something!” stress-releasing adrenaline/cortisol one.” 
Essentially, when we go through stress or mental health problems, it can weaken our vagal tone. Vagal tone refers to how active the vagus nerve is. Vagal tone is weakened by unresolved trauma. Our bodies feel in constant threat and are stuck in the sympathetic nervous system fight or flight mode. A weak vagal tone is associated with high blood pressure, cardiovascular disease, illness, and digestive issues. 
The more you increase your vagal tone and activate the vagus nerve, the better your physical and mental wellbeing. A strong vagal tone is linked to emotional stability, low inflammation, and improved body function. The vagus nerve and the phetic nervous system can be activated to help alleviate anxiety by changing the rate of breathing, such as in relaxed breathing techniques. The impact of this is greater when practised regularly. 
Why not start by trying this deep breathing exercise?
Sit comfortably in your seat. Notice your breathing. Notice the rate and speed, count how many seconds in your inhale and exhale. For visual thinkers, imagine a balloon in your belly. Imagine the inhale is filling the balloon in your belly, you want to breathe as far down into your belly to inflate that balloon as much as possible. When you breathe in, feel your stomach rise and then fall on the exhale, while your chest and shoulder area stays fairly still.
Now try and add an extra second to your next exhale. We’re making that exhale a little longer than our inhale. At your next inhale, pause before exhaling, keep that same longer counter for the exhale. See if you can push that breath from the inhale down into your belly. Continue breathing in this way for 2 more rounds – in 2-3, pause, and out 2, 3, 4 – in again, 2-3 pause, out 2, 3, 4. When you are ready, you can bring the exercise to a close.
Hopefully you’re feeling a little more relaxed, a little calmer. Breathing in a relaxed fashion when anxious can be difficult, it does take time, patience and refocusing energy, but with regular practise, it can be a powerful tool to assist you in lowering the physical symptoms of anxiety.
 Newport Academy , "Understanding the Mind-Body Connection," [Online]. Available: https://www.newportacademy.com/resources/mental-health/understanding-the-mind-body-connection/.
 John Hopkins Medicine , "THE MIND – BODY CONNECTION," [Online]. Available: https://www.johnshopkinssolutions.com/the-mind-body-connection/.
 Health Navigator NZ , "Physical activity & mental health," [Online]. Available: https://www.healthnavigator.org.nz/healthy-living/p/physical-activity-mental-health/.
 H. Health, "Nutritional psychiatry: Your brain on food," [Online]. Available: https://www.health.harvard.edu/blog/nutritional-psychiatry-your-brain-on-food-201511168626.
 A. Hadhazy, "Think Twice: How the Gut's 'Second Brain' Influences Mood and Well-Being," [Online]. Available: https://www.scientificamerican.com/article/gut-second-brain/. [Accessed 2021].
 F. Chughtai, "Improve Your Vagal Tone To Improve Your Mind-Body Connection," January 2021. [Online]. Available: https://medium.com/psychology-today/improve-your-vagal-tone-to-improve-your-mind-body-connection-5dd75807cd59.
 J. Fallis, "How to Stimulate Your Vagus Nerve for Better Mental Health," 2017. [Online]. Available: https://sass.uottawa.ca/sites/sass.uottawa.ca/files/how_to_stimulate_your_vagus_nerve_for_better_mental_health_1.pdf.
 E. Zimmerman, "I Now Suspect the Vagus Nerve Is the Key to Well-being," 2019. [Online]. Available: https://www.thecut.com/2019/05/i-now-suspect-the-vagus-nerve-is-the-key-to-well-being.html.