Pranayama means the restraint, or control of the breath or prana, the life force. There are many forms of breathing practice. Some, such as Ujjayi, are used to create heat and aid your asana practice. Bastrika also creates heat in the body. Sitali cools the body and Nadi Sodhana calms and purifies the body. These are just a few of many. All, except sitali, are done through the nostrils. They also pay close attention to the three phases of breathing, inhalation or puraka, retention or kumbhaka and exhalation or rechaka. Pranayama makes the respiratory system function at it’s best and keeps the mind focused on the present.