You take in 12 to 20 breaths per minute or up to 80 breaths during a workout. In your lifetime, you will probably take more than 70 million breaths of air. Each time you inhale, you move oxygen from the air through your lungs into your blood. From there, it travels to every cell in your body. Cells can't function without oxygen.
Carbon dioxide is the waste product of cells.
It travels through your blood and into your lungs. Then you exhale, or breathe it out. Your lungs are two sponge-like organs that fill most of your chest cavity. They connect to your mouth and nose by branching air passages, called bronchi. In your lungs, the bronchi divide into smaller branches, finally ending in tiny air sacs called alveoli.