The total lung capacity of an average adult is about 6000cc. Generally, though, we use only about 10% of the full capacity of our lungs.
Yogic breathing and pranayama aim to increase air intake by actively using and engaging the diaphragm, as well as the muscles in and around the abdomen, chest, and clavicle region.
In pranayama, a typical abdomen/chest/clavicle breathing ratio is 60/30/10. This means when you inhale, 60% of the inhalation should be in the abdominal region, 30% in the chest region, and 10% in the clavicle region. Similarly, when you exhale, 10% of the air should come from the clavicle region, 30% from the chest region, and 60% from the abdominal region.
The use of the diaphragm in yogic breathing and pranayama is especially important: engaging the diaphragm massages the vital organs and increases circulation to the heart, lungs, liver, stomach, pancreas, intestines, and colon.