In this practice, you must feel the sadness as a bundle of energy in the subconscious, and it is to work with him, it's hard to do at first, but if you practice - it is possible to identify local areas within itself (what yoga and learn - learning about themselves, they just get rid of the dark areas in the his mind - making it lighter - enlightenment).
Before working with sorrow, need extensive work with a sense of joy (ahimsa - joie de vivre), that you should teach your trainer on yoga, ie you must learn to cause joy in all situations and at any time.
Sadness, physiologically, it is likely to be felt in the liver, may manifest sadness, remembering an event or period in my life when it was bright. Then take a look at it (as if) from the outside, but rather from the top, get a lesson in this situation for yourself (very often - sadness - there is a feeling of not traversed life lesson). Once you find a sense and feel - release - release sandwiched energy within yourself and inner emotional freedom, let it be lightning and transient, but the beginning of mortgaged. Each time, inner freedom will be wider and longer and more energy.
Be free, free your mind off the old block (resentment, sadness, irritability), interfering feel the world deeper and brighter !!!
And remember, cheerfulness - the basis of a full spiritual life, but to come to her, to be lived in all the sadness of the world and let it go!