Asana is one of the eight limbs of classical yoga. In the Yoga Sutra, the definitive text on yoga philosophy, Patañjali defines the essential meaning of asana in two words: sthira and sukham. Sthira means stabiltiy, steadiness, firmness and is derived from the root stha which means "to stand." Sukham means ease, comfort, happiness. When the body-mind is in the opposite state of these two -- unsteady, constricted, restless or distracted -- we tend to experience life as continual struggle, conflict, stress, and unhapiness. The practice of yoga postures helps to cultivate a focused steadiness and an effortless ease that is experienced throughout the body-mind and benefits both meditation and everyday circumstances.

The practice of yoga posture differs radically from conventional excercise such as aerobics, weight-training, jogging, etc. The goal of asana practice is not to develop muscular strength or cardio-vascular fitness (although both are possible) but to restore to the body-mind its fundamental state of well-being, ease, and vibrant alertness.

Yoga postures work on all dimensions of the body-mind -- "physical" through healing, strengthening, stretching and relaxing the skelital, muscular, cardio-vascular, digestive, glandular, and nervous systems; "mental" through the cultivation of a quiet and peacefull mind, alertness, and concentration; and "spiritual" by way of preparation for meditation and cultivation of inner strength.