Asana must be established within. Just getting into the posture is not asana. It must be established within in such a way that your posture, breathing patterns and your dristi should synchronize with each other.
It doesn’t matter how many hours you practice. What matters most is how much devotion you have to your practice. And devotion can come only through complete surrender. Through complete surrender one can feel the purest form of love. Through complete surrender one can achieve the highest form of yoga. This synchronized and harmonious state of your existence will enable you to create emptiness within you. Through this emptiness, pranic energy can flow freely. Through this emptiness, panch koshas (the five bodies) can be merged together and finally one can get a glimpse of Ananda (bliss) .