From Dynamics of Yoga, Swami Satyananda Saraswati

Yoga, as a science of living, is accepted in theory by quite a large number of thinking individuals. If we look closely at the development of the yogic movement in various parts of the world we will find that its application is largely confined to the physical aspects, viz. training in various asanas and pranayamas. This is indeed desirable as the physical well being of an individual is essential for further spiritual development.

The first condition of human happiness is the possession of a sound body. A healthy body is an asset to enable man to work his way in everyday life. It is common knowledge that a sound mind, or a healthy mental condition, prevails in a healthy body. The yogasanas thus form the backbone of applied yoga.

The principal asanas are said to be eighty-four in number. A preliminary study, even theoretical, of the different postures will reveal that they are intended to serve the various parts of the body. Current systems of physical exercise help to build muscles and make an individual muscular. However, it is an everyday experience that even a muscular man is unable to stand the strain and stress of life for a long time. It follows, therefore, that there is a constant and inescapable action of the mind on the body which the physical exercises are unable to tackle. Herein lies the main difference between asanas and physical exercise.

The asanas are not only aids to keeping the physical system healthy and strong but they also help in an imperceptible way, with the assistance of their counterpart, pranayama, to build up a mental resistance to disease. They take into account various parts of the body and joints, and form in themselves a complete nerve toning system. The entire physical organism is dependent upon the nervous system, and unless the nerves are kept ft and nourished, the mere building up of muscles will not be of any use. Furthermore, the regular practice of asanas in daily life does not entail great strain upon the physical energy and time of an individual. A person with a weak constitution can also be admitted into an asana course, under proper guidance.

It may be of interest to note that many asanas are named after birds or animals, for example, mayurasana (the peacock pose), shashankasana (hare pose), bhujangasana (cobra pose). If we try to understand the implications of the asanas they might give an interesting clue. After a day’s work the body is fatigued, and our common belief is that it will be rested by assuming the horizontal position in which we sleep. How do birds and animals rest? Nature has deprived them of the comfort of a horizontal position and yet they do rest. Therefore, the poses in which they stand or rest give the clue to the asanas. As mentioned before, asanas are not strenuous exercises but are recreational poses which refresh a tired body and give it the necessary energy to carry on the day’s labour with comfort and ease.

It may be necessary to explain here that asanas do not entail exertion as other physical exercises do, nor do they require rich food to make the body healthy. As a matter of fact, the entire concept behind asanas is to keep the human body fit and active as long as it lasts.