You can learn a Siddha Viddhai called Vaasi Yoga for digesting the air in the best way. I would say that Vaasi Yoga is the best of all the breathing exercises that I have learnt so far.
This exercise is not easily available for all the people to learn. But, it is very good to learn if you get an opportunity to learn it. Those who desire to learn this can search on the internet using the word Sivananda Paramahamsa, Vadakarai, Kerala, and Siddha Viddhai Dhava Aalayam, find out the Ashram nearest to your place where it is taught and go there to learn it. Let us all live a healthy life!