That's important because most of us never take a single deep breath all day long. To exhale, suck your belly button toward your spine to push the diaphragm up and empty all the air from your lungs.
Inhaling deeply brings a chemical called nitric oxide from the back of your nose and your sinuses into your lungs. This short-lived gas dilates the air passages in your lungs and the blood vessels surrounding those air passages so you can get more oxygen into your body. Nitric oxide also doubles as a neurotransmitter to help your brain function at higher speeds.
Also, yoga and the deep breathing associated with it help create a negative pressure in your lungs, acting as a vacuum cleaner to draw lymphatic drainage back into your veins.
What are lymphatics? When blood feeds your tissue, some of the waste material seeps out into spaces between cells and becomes lymph. Your lymph nodes serve as a portal to pass waste material back into your blood vessels for cleansing; these same nodes become inflamed when we are sick, which is why you can feel them enlarge. Yoga stimulates flow in your lymphatic system by exercising your muscles and through the vacuum action of deep breathing.
Find out more about this book:You: Being Beautiful - The Owner's Manual to Inner and Outer Beauty