IN one of my shivirs,one woman asked -"swami ji i am doing pranayam for 2 years still i am not getting any benifit out of it?" so i answered her by this article.

BEFORE Doing PRANAYAM one needs to follow underneath points-:

1.EMPTY STOMACH -:Stomach should be empty before starting pranayam ,early in the morning.
If you are doing pranayam in the evening then a person should try to have a gap of 4-5 hours between the meals.AS if the stomach is not empty so ,instead of benifiting pranayam can cause bad impact on our body like Undigestive food may come out of our body.
so stomach should be empty or a gap of 4-5 hours between the meals shouls be present.

2.ISOLATION FROM ZERO POTENTIAL-:According to science earth is said to have zero potential.While doing pranayam one needs to sit isolated from the ground.Isolation from ground provides sufficint energy to the body.Without proper isolation energy is not circulated properly within the human body.
so its better if one sits on the mat,cloth or even on the bed.The sole aim is just to provide isolation of body from the ground.

3.POSITIVE THINKING-:Before starting pranayam one needs to think positively as if the person doing pranayam is sitting with the god and god is giving all its blessings to you.SO the ultimate aim is to keep the mind in peace and to think positive.Positive thinking develops positive energy in the body.And this positive energy itself cures several diseases