People are performing various body movements and say that they are doing yoga. First of all, these people should know that body works and movements do not make a complete of yoga.
A person can attain perfection in asana only when he conquers the six enemies and becomes a yogi.
Abhyasa and sadhana are the two steps to perfect an asana. Abhyasa means practice. Practice means repeating what has been learnt again and again.