You will find that people from different religious and those with different view points on life, are great students of Yoga. Though Yoga has its roots in Indian thought, the content and application is universal. For the time being let us say, to unite breathing and body movement. Another meaning for Yoga is, 'achieving something that was previously not achievable'. Yet another meanings for Yoga is, 'to be totally attentive to one's action'.
Yoga is about adapting oneself to constant changes of the mind and body.
The golden principle is, to start where we are, how we are, and then we progressively achieve the goal for which we started doing Yoga. Along the journey you are likely to drop certain habits and thoughts that are counter productive to your healthy living. Father Yoga as such, is a vast area of study and practice which includes spiritual progress in oneself. Asana' means, a posture. The root meaning of this word is actually 'to be established in a particular position'.