The Vagus Nerve Part 3: by Wendy Hayden
We can’t control most of our autonomic nervous system. We can’t make our heart beat slower by thinking about it or intentionally releasing a hormone. But we can control one thing that is usually controlled by our autonomic nervous system. We can control our breathing. Deep breathing activates neurons that detect our blood pressure. When we activate these neurons, they signal to the vagus nerve that our blood pressure is becoming too high. The vagus nerve then secretes the neurotransmitter acetylcholine, which slows the rhythm of the heart. Deep breathing also stimulates the vagus nerve by stretching it when it passes through our diaphragm. Deep breathing is one of the easiest and most effective ways to transition to a parasympathetic state. There are many ways to practice therapeutic deep breathing and stimulate our vagus nerve. Practicing deep breathing regularly, over time, can increase our vagal tone, helping us to switch our system to a predominantly parasympathetic state, turning off our fight-or-flight response. Breathing through our nose instead of through the mouth signals our brain that we are safe. When we are stressed, we will breathe through our mouths. There are many types of deep breathing that you can practice that will help stimulate and tone your vagus nerve. Breathing in for 4 seconds and out for 6 seconds is a very basic, but effective technique. Breathing out longer than breathing in bears down on the diaphragm, making it more effective. Always exhale longer than you inhale. You want to breathe forcefully enough that your belly goes in as you inhale and out as you exhale. Take a moment and practice deep belly breathing. Put your hand on your belly and feel it expand as you breathe out. You can also place your hands on your ribs with your elbows out to your sides and breathe in, feeling your ribs expanding and filling with air, and then breathe out, feeling your ribs contracting as you release your breath. As a caution, always do any breathing exercises in a safe environment. Do not practice while in the bath, swimming, driving, or in any situation where it might not be safe to practice. I recommend sitting in a chair or couch or laying on the floor or your bed. Listen to your body and stop if you feel uncomfortable or faint. One yogic breathing technique is to breathe very deeply, expanding your belly and your chest as you take in the air. As you exhale, hum while breathing out, expelling air from your belly and chest as you hum. You want to breathe out while humming for as long as you can. Not only does the deep breathing stimulate the vagus nerve, but so does the humming. Alternate nostril breathing (ANB), or Nadi Shodhana, is another yogic breathing technique. To practice Alternate Nostril Breathing, sit quietly and breathe through each nostril separately. Plug one nostril by pressing against the nostril with your finger and breathing in the opposite nostril. Go back and forth between each nostril, slowly and rhythmically. Press your left nostril closed, breathe in through the right, then plug the right nostril, unplug the left nostril and exhale through the left, then plug the left nostril, unplug the right nostril and breathe in through the right. During this practice, have a finger closing at least one nostril at all times. Think of it as breathing air into your head through one nostril and then breathing out that air through the other nostril. Research has shown that Alternate Nostril Breathing can help lower blood pressure and increase feelings of calm. Cold exposure is increasingly being recognized as an effective way of stimulating the vagus nerve. Cold exposure can help to activate the nervous system and create a calming effect on the body. It stimulates the vagus nerve by sending a signal from the skin receptors to the brain. This activates the parasympathetic nervous system and helps to reduce stress, improve digestion, reduce inflammation and improve overall health. Cold exposure can be achieved in a few different ways. The most common way is to take a cold shower or a bath. A cold shower is a simple way to stimulate your vagus nerve daily. Ending your shower with 30 seconds-2 minutes of icy cold water can stimulate your vagus nerve. Cold water therapy, also called intermittent hypothermia or cryotherapy, is becoming more popular as it has been shown to reduce inflammation, improve skin health, and improve cognitive performance. Lowering the temperature of the water (not freezing) for a few minutes will help activate the vagus nerve. Sitting in a cold or icy pool for a few minutes can also help to stimulate the vagus nerve if you have one available. This can help to increase parasympathetic activity and improve digestion. Breathing in cold air helps to stimulate the vagus nerve. This can be done by going outside when it is cold and taking deep breaths. You can breathe in cold air, either through your nose or mouth. Simply take a deep, slow breath and hold the air in for a few seconds before exhaling. Cold can trick your body into survival mode, switching you into a sympathetic state. Studies have shown that as you adjust to cold exposure, your sympathetic response declines, and your parasympathetic response increases. If you find a cold shower too hard, you can start by putting your hands or feet in cold water. Work up to putting them in ice water and increasing the time you leave them in the water. You can also splash your face with cold water. Plunging your face in ice water triggers your dive reflex. This stimulates your vagus nerve both through the cold and from the lack of breathing. You can also use ice packs or ice to stimulate your vagus nerve. Just be careful to protect your skin so you do not get ice burn. Going outside in the cold for a few minutes or longer can also stimulate your vagus nerve. If you live in a climate where you have cold weather, you can take advantage of this simple way to stimulate your vagus nerve.
