When the speed of quiet breathing is deliberately reduced, the result is deep breathing; on the contrary, if that speed is willfully increased, then the result is fast breathing. However, here the short timed inhaling-exhaling is not implied. It is expected that one should increase the speed of breathing by inhaling and exhaling fully. One has to practice to continue the cycle of quick breathing with constant practice. This sort of breathing is easy to understand & easy to practice. Naturally, its benefits are also limited. The fast breathing clears the nasal passage and gives a good exercise to the parts involved in the breathing system. At times while practicing quick breathing, one feels whirling sensation in the head. But one should not bother about it. On such occasions, stop fast breathing and begin quiet breathing. There occurs no problem, once there is sufficient practice and habit of this type of breathing. This breathing is also practiced in Padmasana or Vajrasana. Before actually beginning the study of deep breathing, one should practice quick breathing for 2-3 minutes in order to get the nasal passage cleared, fast breathing need not be done for a longer period.
After examining and understanding these basic systems of breathing, let us turn to the supplementary types of breathing: The breathing passage in the nasal cavity is divided into two owing to the mid partition between two nasal cavities, viz. the left and the right.
In Yoga, the left nasal cavity is called "Chandra Nadi" (The moon passage) or "Ida Nadi" and the right nasal cavity is known is "Suryanadi" (The sun passage) or "Pingala Nadi". Inhaling (Puraka) and Exhaling (Rechaka) can be done through either one of these nasal cavities or with both of them. The supplementary types of breathing are based upon these two nasal cavities. In this system of breathing one nasal cavity is kept closed, while the other one open. For this purpose the fingers of the right palm are arranged in a special manner. This special position of the fingers is called "Pranava Mudra", i.e., the position of Pranayama.