Heart rate alterations in different types of pranayamas.

Pranayama is a state of voluntarily regulated breathing while the mind is directed to the feeling of the flow of breath or prana (1). A typical cycle of the slow type pranayamic breathing involves the phases of inhalation, exhalation, and timed breath-holding (kumbhak) either at end-inspiration stage or at endexpiration, or at both stages. There are different kinds of pranayamas, varying according to the durations of the phases in the breathing cycle, and in other details like the nostrils used, and bandhas employed.