So we should all be actually breathing through our noses, the potential benefits:
Dr. John Douillard claims that nose breathing enhances deep breathing in which the diaphragm contracts and increases the cavities of the lungs. Because the majority of the blood is located at the bottom of the lungs, more oxygen will be absorbed into the blood. The slower release of air through the nostrils will keep air in the lungs for a longer period of time, furthering the absorption of oxygen. With more effective breathing, the heart rate is reduced, less stress is placed on the heart, greater stamina, and rapid recovery from sport activities. Nose breathing becomes the function of the parasympathetic nervous system and leads to improved concentration and performance — helps to stay calm, relaxed, and focused — while in the "zone." Dr. Douillard calls the zone, "being in the eye of the hurricane" — calm and powerful!