Yoga is a system of exercises for physical and mental nourishment. Apart from being a system of exercise, an important aspect of Yoga is that of self-discipline.
The fundamentals of Yoga were systematically presented by Patanjali in a treatise known as Yogasutras i.e. Yoga Aphorisms. According to Patanjali, within the human body there are channels called Nadi and centres called Chakra. If these are tapped, The energy hidden in the body can be released. This energy is called Kundalini. The release of Kundalini enables the body to acquire many powers which are normally beyond its capability.
Stages of Yoga
Yama (universal moral commandments), Niyama (self-purification through discipline), Asana (posture), Pranayama (breath-control), Pratyahara (withdrawal of mind from external objects), Dharana (concentration), Dhyana (meditation) and Samadhi (state of super-consciousness) .
But though the Yogasutras were formulated 2000 years ago, Yoga has been practiced for countless generations, it is only in the last few years that scientists have begun to recognise the powers of yoga. It has now been established through experiments that by practicing Yoga, several ailments can be cured. Tests conducted on Yogis show that they do acquire extraordinary physical powers. For instance, they can live without oxygen for a long time, they can also adjust their metabolism if they have to remain without food for long periods. Yoga is being increasing applied in the field of Physiotherapy.
There are innumerable asanas (poses) in Yoga. Most of them derive their names from the semblance of the body in those poses to different animals and objects. Yoga is a multifarious system, there are various forms of discipline touching different aspects of human life, which are brought under the heading Yoga.