Real asanas and mudras are a catharsis, an expression, an overflowing. And the more they overflow, the more weightless you begin to be. Then a day comes when you are completely weightless; a moment comes when you are not bound by gravity. Weightless! Only in this weightlessness does the flight of the alone to the alone take place.
     If you practice asanas there will be no catharsis, only suppression. That is the basic difference: if you practice asanas they will be suppressive, but if they come to you spontaneously they will be expressive, there will be a catharsis.
     If you impose asanas on yourself, the action is just part and parcel of your total suppressive routine. If you impose asanas that your mind is not ready for, you will force your body into a particular posture and the body will have to follow your will. This type of exercise, if done to its logical conclusion, will create a split in the personality. Then you will become two: the one who is suppressed and the one who is suppressing.
     Yoga, to me, means becoming one, not two. It is integration, not splitting. I call an asana yogasana only when it comes automatically. If it is imposed, then it is not concerned with yoga at all. Yogic exercises are gymnastics, not Yoga. That is why I have not used the word yoga but have been using the word "asana."

     Yogasana is an asana that has come to you, which has happened to you; otherwise an asana is no different from anything else that is imposed on you, any physical discipline. It may prove health giving but it can never prove spiritual; it can never help to integrate you. The health benefits that you derive will be at a very high cost because your personality will be splitting in two. The whole nature of the experience of those people who practice asanas begins to be less and less spiritual and more and more physical.
     This is a curious phenomenon: these asanas seem to be meditation-oriented – they are supposed to be – yet all over the world, wherever asanas are talked about, dhyana, meditation, is the least talked-about subject! Now, the whole thing has become topsy-turvy: they teach meditation along with asanas, as if meditation were only another asana! It is not an asana at all.
     Meditation is the ground, it is the base, it is the seed.
     Everything must be meditation-oriented, because meditation is first, and everything else follows.

Osho The Great Challenge