Recently I just came across this site. I think its useful and has some points that contrary our old believes with facts, that "The more you breath, the less oxygen is provided to all vital organs"!
According to Prof. Buteyko, teacher of normal breathing, the balance of O2 and CO2 is the key to maintain long life health. Learning to breath less can even eliminate chronic disease such as fatique, asthma, heart disease, cancer and even AIDS or HIV.
To those breathing practitioners such as Yoga & Qi Gong lovers, please read this site before you go further. It shall give more information and you will be more cautious when engaging with these activities.
Here's the link: http://www.normalbreathing.com/
