Most people breathe using their chests—taking shallow breaths using the intercostal muscles (between your ribs) to expand the chest. But abdominal, or diaphragmatic, breathing, also known as “belly” breathing, helps get more oxygen to your body—and your brain. With belly breathing, when air is taken in, the diaphragm contracts and the abdomen expands; when the air is exhaled, the reverse occurs. You can test yourself for abdominal breathing by laying your hand on your belly as you breathe. If it rises as you inhale, you are breathing with the diaphragm. If it lowers, you are breathing with the chest. To practice abdominal breathing, imagine that your in-breath is filling a balloon in your belly. When the balloon is full, exhale until you feel it is completely empty. Just a few of these deep abdominal breaths will bring relief from tension and ease stress. Research also suggests that the mere practice of focusing on your breathing helps calm the mind and sharpen attention. Deep breathing can also help elevate the production of neurotransmitters such as serotonin, making you feel happier.