Various nasal breathing techniques can stimulate the parasympathetic nervous system, which regulates digestion, lowers blood pressure and improves sleep quality. Unilateral forced nostril breathing, or inhaling exclusively through one nostril, can also stimulate different parts of the brain and improve your performance on right-brained or left-brained activities.
Alternate Nostril Breathing
Also known as channel cleaning breath, alternative nostril breathing is the practice of exhaling and inhaling through one nostril at a time. According to Yoga Journal, channel cleaning breath can lower the heart rate, reduce stress and anxiety, promote balance between the two sides of the brain and purify the pathways in the body through which energy flows. In a 2008 study conducted by the Department of Physiology at Nepal Medical College in Kathmandu, Nepal, researchers tested the effects of alternate nostril breathing on a group of healthy adults, who engaged in alternate nostril breathing for 15 minutes every morning for four weeks. Participants demonstrated significant decreases in heart rate and blood pressure and an increase in parasympathetic activity.
To practice alternate nostril breathing, sit in a comfortable position and close your right nostril with your thumb. Inhale through your left nostril, then close that nostril and exhale through the right. Repeat the process, this time inhaling through the right nostril and exhaling through the left. Repeat the entire cycle three to five times.
Right Nostril Breathing
Various studies support the idea that inhaling through one nostril for an extended period of time can stimulate the function in the opposite side of the brain. Research conducted at the Department of Neurosciences at the University of California San Diego showed that EEG amplitudes increase in the opposite brain hemisphere in participants who engaged in single nostril breathing. In a study conducted at the Swami Vivekananda Yoga Research Foundation in Bangalore, India, participants performed better at a left-brain activity after engaging in right nostril breathing and alternate nostril breathing. To practice right nostril breathing, close your left nostril with your thumb and inhale through your right. Release the left nostril and close the right for the exhale. Continue inhaling through the right nostril and exhaling through the left for one to three minutes. According to Yoga Journal, right nostril breathing stimulates the brain and increases body heat. Right nostril breathing may be beneficial before performing left-brain activities such as logical and analytical tasks. A separate study at the Yoga Research Foundation also found that right nostril breathing was associated with a significant increase in metabolism.
Left Nostril Breathing
To stimulate the right side of the brain, inhale through the left nostril and exhale through the right. Yoga Journal reports that the effects of left nostril breathing are the opposite of right nostril breathing: it can calm the brain and cool the body, and is useful in the treatment of obsessive-compulsive disorder and anxiety. Kundalini yoga recommends practicing left nostril breathing before bed to engage the parasympathetic nervous system and relax the body.