Progressive levels
The term ‘progressive’ indicates a specific yogic sequence. From the yogic perspective, within this physical body there are four other bodies; we are the owners of five bodies. Just as when you open up a Russian doll, inside there is another doll; you open that up and inside there is another doll, and so on. The first one is big and the rest are each smaller. Our body is like that.
The outer body is known as annamaya kosha, the body made up of matter. Kosha means dimension and maya means filled with; therefore, ‘annamaya’ kosha means dimension filled with anna or matter. The inner body is known as manomaya kosha, the body of mind, the mental dimension. Then there is pranamaya kosha, the energy dimension; vijnanamaya kosha, the consciousness dimension – vijnana means specific knowledge of the self or consciousness; and anandamaya kosha, the bliss dimension – ananda or bliss arising out of spiritual realization. These are the five bodies, koshas, all contained within each other.
When all the koshas work at their optimum positive level that is perfection of hatha yoga. When your body is functioning optimally, there is good health and the senses are all fired-up and active, there is a sense of physical vitality, lightness, euphoria and dynamism. When the mind is happy, there is a feeling of buoyancy, contentment, positivity, optimism; nothing appears dark, everything is seen as light and bright. This optimum condition of body and mind is the perfection of hatha yoga.

Blocks in koshas
Blocks are formed at the five levels of koshas naturally and unconsciously due to lifestyle and circumstances. For example, when you are under stress, certain areas of the body become affected, three regions in particular. One, the neck region, where the neck and the shoulders become tight; two, the abdominal region, where the muscles of the abdomen become tight, when you pull the abdomen in, in the ‘fight or fight mechanism’; three, the perineum where you pull in the perineum whenever there is stress.
A normal experience of stress can unconsciously create muscular stiffness and blocks that reduce circulation of blood and prana. Your natural pattern of sleep and hunger can become disturbed. Sometimes when you are mentally and emotionally burnt-out you cannot sleep; the stress affects the relaxation pattern. The hunger is also affected, some people cannot eat and some people overeat under stress.
Just as there are blocks of the body, there are blocks of prana, which are also three. The pranic block is perceived in the granthis or knots that are created in the pranic body unconsciously and naturally. These blocks have to be cleared for the prana to flow. Once the prana begins to flow, the behaviour of the mind changes and there is a sense of euphoria and happiness. Thus in yoga we work through the five bodies to attain an optimum state of being.

24 September 2016, Ganga Darshan, Munger, Hatha Yoga Training – Module 1 (Extract)
Swami Niranjanananda Saraswati