Slowing and deepening the breath has been shown to have a profound effect on the heartbeat, and therefore mental attitudes and relaxation. It improves the elasticity of the lungs and maintains optimal oxygen/carbon dioxide balance in the body. Pranayama ("prana"- life force/"yama"- regulation) utilises and directs the energy of the breath to aid healing, to revitalise and calm and gain mastery over the mind. This involves slowing the breath, breath retention and in it's more advanced forms the bandhas to direct the prana in the body.   Types of Pranayama include: Nadi Sodhana - alternate nostril breathing Bhramari - humming breath Sitali - cooling breath Sitkari - the hissing breath Ujjayi breath - the psychic breath Surya Bheda breath - Sun breath & Chandra Bheda - Moon breath Bhastrika - bellows breath   Life is Breath, Breath is Life.