I remember the first time I recognized how much yoga changed my breathing. I was teaching a biology unit on respiration and wanted to demonstrate how much carbon dioxide was in our exhale. I started to exhale into a beaker of water with a universal indicator and made bubbles for about a minute until the water turned green (I had exhaled enough water to make the water acidic). The students were amazed - not about the color change but that I was blowing bubbles for an entire minute! Many students asked to try it themselves. None of the students could exhale long enough to make the water change color. Although it appeared like I had magical lungs, in reality yoga helped me strengthen my diaphragm and intercostal muscles so I could access my full lung capacity.