Yoga suggests that the physical body is supplied with two types of energy. One is mental energy, the other prana energy. The theory is that the two energies supply our vital organs.
The Energy Network
The prana energy flows through the body in channels called nadis. Here is where yoga comes to grief with science – since these channels seemingly have no physical manifestation. Dr. Hiroshi Motoyama in Japan and Dr. James Oschman in the United States, have explored the possibility that the connective tissue running throughout the body provides pathways for the energy.
The original wisdom of the sages and gurus is said to have been hard won with many years of yoga practices. In Shiva Samhita there are said to be 350,000 nadis. Prapanchasara Tantra suggests 300,000 and Goraksha Satarka 72,000.
We are told there are ten main nadi with three being very significant. They are ida, pingala and sushumna. You could write a book about each. Sushumna is the largest and runs from the base of the pelvis to the crown of the head. It channels spiritual energy. Ida channels mental energy and pingala vital energy. Ida and pingala spiral up around sushumna ending at the top of the nose.
Following the six major chakra (energy centres) from Mooladhara, root chakra at the base of the pelvis to Ajna (third eye) at the centre of the forehead, pingala flows to the right from Mooladhara and crosses ida at each chakra. Ida is flowing to the left from Mooladhara.
Swara Yoga
If you watch your breath you will see that sometimes you will breath mostly through the right nostril at other times through the left. When the right nostril is open pingala nadi is more active than ida nadi. Pingala is uplifting, dynamic energy, or solar, sun energy. Left nostril breathing is mental, lunar, relaxing peaceful energy. This is swara in yoga. Swara yoga suggests that prana alternates from ida to pingala every hour. When the breath is is both nostrils the sushumna spiritual energy is flowing.