In yogic philosophy each of us are composed of five concentric layers known as Koshas. The first and most internal Kosha is the Annamaya Kosha, which corresponds to the physical body. The second Kosha is called the Pranamaya Kosha or breath/energy body. The Manamaya Kosha, Vinanamaya Kosha, and Anadamaya Koshas correspond to the mental, wisdom, and bliss bodies respectively.
This model can be used to conceptualize some of the more esoteric yoga principles such as Prana, Nadis, and the Chakras. In Western Society when people say they practice yoga, most mean that they practice asana-one of the eight limbs of yoga. But when practiced with precision, attention, and integrated breath work asana can lead a practitioner into some of the more subtle realms of yoga. The work in ones asana practice is primarily physical. However, by combining breath with movement or learning various breathing exercises one learns to use the breath to relax the body and mind by manipulating the nervous system. Just as the breath is used as a gateway between the body and the mind, the Pranamaya Kosha links the physical and mental bodies. So asana first instills the discipline, awareness, and devotion that facilitate our ability breath deeply and develop meditative qualities such as one-pointed attention. According to yoga sutras 2.46-2.48, Asana gives us the strength and flexibility to literally be more comfortable in our own skin and sit with more steadiness and ease in stillness. Thereby allowing us to practice Pranayama and meditation.
Breathing exercises, known as Pranayama, lead to physiologic and energetic changes via the manipulation of Prana. Literally Prana translates to “Vital Life”. It is the energetic force that flows through us to sustain life. In China Prana is referred to as chi, in Japan as ki, and in Polynesia as mana. In yoga, one of the most powerful and accessible ways to move Prana is via the breath. The ancient sages taught that Prana was inhaled through the breath and subsequently moves into the blood and becomes concentrated in seamen and vaginal fluids. Because of its relationship to breath, Prana is often confused as being synonymous with air or breath. Rather the breath is a vehicle for Prana. Another common misconstruction is that Prana is the soul or one’s true self, but ancient text state that it is an “instrument of the soul
Swarmi Dharmanada explains that Prana has both a gross and subtle form. On the gross level Pranayama nurtures and sustains the physical body. Whereas the subtle aspect of Prana maintains the Pranamaya Kosha and serves as the link between the physical and mental bodies. The distinction may be clarified by examining the energetic forces of Prana. Prana flows through 72,000 conduits in the body called nadis. In yoga there are three main channels for Prana. The Ida, the Pingala and the Sushumna. Because the brain controls the ipsilateral (same) side of the body, Ida relates the right side of the brain and the left side of the body. Where was Pingala relates to the left side of the brain and the right side of the body. The Ida and Pingala channels terminate at the left and right nostril, respectively.
Swarmi J explains that, in most individuals, Prana normally flows through either the Ida or Pingala. So the work of yoga is to access and awaken the other channel in order to balance the flow of energy. Breath that flows through the left nostril is cool, lunar and feminine. Breath that primarily flows through the right nostril is hot, solar, and masculine. Chronically breathing through one nostril can be a symptom of emotional, mental, or physical dis-ease. Learning to breathe through one nostril at a time helps us to balance the flow of energy through the Ida and Pingala and correct the underlying imbalance. Nadi Shodana, is one of the primary Pranayama techniques used to achieve balance between the hemispheres of the brain and energetic flow through the nadis. Thus the breath is one tool that allows us to understand the energy currents and blockages in the body from a yogic perspective.
It is important that the nadis are unobstructed and able to contain energy flow, because they feed the chakras. The first six chakras arise from the six intersections of the Ida, Pingala, at the Sushuma (central channel) forming vortexes of energy at these points in the body. Anatomically these chakras overlie the major nerve ganglia of the body.