PRANA is to yoga what electricity is to modern civilization. Let us suppose for a moment that we have been taken back by a time machine into the presence of a yogi of two thousand years ago and that we are trying to explain to him what our own way of life is like, with its aeroplanes, telephones, radios, televisions, refrigerators, motor cars, vacuum cleaners, satellites and space rockets, electronic brains, pocket lamps, tramcars and food mixers – but without mentioning electricity. The view he would get of our civilization would be very false indeed, for he would understand nothing of its basic driving force, the electricity which we use without thinking much about it except in the event of a power failure.
In the same way, to be ignorant of Prana, or not to appreciate its existence and its influence on our bodies, how to store it and direct it at will, is to be ignorant of the true yoga. Of course it is possible to practise the asanas without being involved with prana, because to some extent the postures almost automatically ensure pranic balance even though the adept is little concerned with it. But after a certain period of such practice he reaches a limit. Once the technique of the postures is acquired the adept must go on beyond the stage of purely mechanical and material execution of the asanas and similar yogic exercises if he is to reach the state of Pranayama.
-from the book, “Like the flowing River”,
by Paulo Coelho, published by Harper Collins