Two of the most important models in yogic anatomy are the nadi system and the Kosha model. Together, they provide a comprehensive framework for understanding the human being as a multi-layered organism in which the physical body is only the outermost and most visible layer. Yoga practices work across all these layers simultaneously, which is why the effects of yoga go well beyond what physical training alone can produce.
The Nadi System
As introduced in the chakras section, nadis are channels through which prana (vital life force) flows. The classical texts describe 72,000 or more nadis in the subtle body, but three are of paramount importance for practice: Sushumna (the central channel), Ida (the left channel), and Pingala (the right channel).
The key insight of the nadi system is this: most people’s prana flows almost exclusively through Ida and Pingala, oscillating between the two. The pranic current in Ida predominates during rest, emotional processing, and introversion. Pingala predominates during physical activity, extroversion, and analytical thinking. Sushumna, the central channel that leads directly to Sahasrara Chakra at the crown, is almost entirely inactive in most people.
The goal of all Hatha Yoga — asana, pranayama, mudra, bandha — is to balance and purify Ida and Pingala so thoroughly that prana spontaneously begins to flow through Sushumna. When this happens, the state of meditation deepens beyond what ordinary concentration can achieve, because the mind is no longer oscillating between the two poles of activity and rest but is established in the central channel of pure awareness.
Nadi Shodhana and the Nadis
The practice of Nadi Shodhana (alternate nostril breathing) directly targets the balance of Ida and Pingala. The left nostril is connected to Ida; the right nostril to Pingala. By breathing alternately through each nostril with equal duration, the practitioner equalises the flow in the two channels. When both nostrils are equally open — a state that naturally occurs for brief periods several times per day — prana is balanced and meditation becomes accessible. Nadi Shodhana cultivates this state intentionally and for longer durations.
The Five Koshas
The Taittiriya Upanishad describes the human being as consisting of five sheaths (koshas) nested within each other like Russian dolls, from the grossest physical to the subtlest:
1. Annamaya Kosha — The Food Body
The physical body, sustained by food (anna). This is the layer most directly worked by asana and Shatkarma. It is the layer we are most familiar with and most identified with. The physical benefits of yoga — flexibility, strength, health — happen at this layer.
2. Pranamaya Kosha — The Energy Body
The vital energy body, which pervades and animates the physical body. The nadis, chakras, and Pancha Pranas operate at this layer. Pranayama is the primary practice that works directly on the Pranamaya Kosha. When prana is strong and balanced, the physical body is healthy. When it is depleted or disturbed, physical illness follows.
3. Manomaya Kosha — The Mental Body
The layer of thoughts, emotions, memories, and habitual patterns of perception. The ordinary conscious and subconscious mind operates here. Pratyahara (withdrawal of the senses) and Dharana (concentration) work primarily at this layer. Most psychological suffering occurs at the level of the Manomaya Kosha — in the stories the mind tells about events rather than in the events themselves.
4. Vijnanamaya Kosha — The Wisdom Body
The faculty of discernment and higher intelligence. This is the layer that can distinguish between what is real and what is a mental projection, between the permanent self and the transient contents of experience. Jnana Yoga and deep meditation work at this layer. When the Vijnanamaya Kosha is active, the practitioner is no longer identified with every thought that arises.
5. Anandamaya Kosha — The Bliss Body
The deepest individual sheath — the experience of pure joy that is accessed in deep sleep, in Samadhi, and in moments of profound beauty or love. It is the last veil before pure consciousness (Atman). Even this layer is not the self — it is an experience, and the self is the one who experiences it.
Practical Application
The Kosha model gives teachers a way to understand why the same asana sequence produces different effects in different students on different days. One day a forward bend releases physical tension (Annamaya). Another day the same posture brings up an unexpected emotion (Manomaya). The practice is always working across all layers — the practitioner’s awareness determines which layer they are most in contact with at any given time.
Learn This at Medhya Laya
Study nadis and the koshas with qualified teachers in our Hatha Yoga programs in Rishikesh.