One of the health advantages of singing and chanting is that it strengthens the lungs! Singing can even cure asthma! The lungs are composed of tiny tubes that end in alveoli sacks. The sacks are where the exchange of oxygen and CO2 happens with the blood. When we take a diaphragmatic breath for singing, we stimulate the bottom of the lungs which are pulled down and stretched sideways by the descent of the diaphragm. The majority of the exchange of gases within the blood (O2 and C02) take place here. Asthma sufferers and others with lung disorders tend to breath in the top of the lungs, where most of the inflammation of the tubules usually is. By learning to sing, someone with asthma can access other parts of the lungs for breath and open up and strengthen the lungs.
photo from National Heart and Lung Institute www.nhlbi.nih.gov/