Yoga, an ancient Indian concept, represents the way of life which endows perfect health comprising physical, mental, ethical and spiritual development. In Sanskrit, this word means `to unite`. Indeed, the practice of yoga leads to the integration of the soul with the Supreme Being. This Hindu discipline is also put into practice to lead a healthy life. The human body is made of a physical body, a mind and a spirit, and the three parts are so dependent on each other that any disturbance in one part affects the whole system. Yoga, thus, has a holistic approach as it regards man as a whole being with body, mind and soul.

History of Yoga
Yoga is an age old Indian body of knowledge. Yoga evolved as a separate identity in Buddhism and Jainism as well. There are several historical sources that trace the existence of yoga to Indus Valley civilisation as well. Seals bearing the image of a figure seating in a yogic pose were excavated from Mohenjo-Daro. The Rig Veda, Yajur Veda, Atharva Veda and the later Satapath also discuss yoga. Karma Yoga, one of its branches, is to be found in the Lord Krishna`s divine discourse in Bhagavad Gita. Later on, yoga was systematically compiled by Maharishi Patanjali in 5th century BC. He simplified the concepts and principles of yoga so that it could reach out to the masses as well.

Types of Yoga
Yoga can be classified into certain heads. According to Hindu Philosophy, the major branches of yoga include Raja Yoga, Jnana Yoga, Karma Yoga, Bhakti Yoga, Hatha Yoga, Mantra Yoga, Japa Yoga, Purna Yoga, etc. The heritage of yoga was actually handed down from teacher to pupil. Thus, with the passing time new techniques were added to the ones already learned. Thus, several branches of yoga came into existence. Each branch has its separate goal. For instance, Hatha Yoga aims at creating an immortal body that allows mastering nature; on the other hand Raja Yoga aids in discovering the true identity of the self. Different religious beliefs have also contributed in shaping the various kinds of yoga in India.

Yoga Asanas
There are about 84 million postures and these include the pattern of sitting of different species which are known as `Asanas`. The asanas had been explained by Patanjali while discussing the Bahiranga Yoga or Ashtanga Yoga for the first time. Yoga insists on the primary need for day-to-day good health. This has to be achieved through physical education which, in turn, promotes moral and mental discipline and psychic absoluteness. Asanas are instrumental in achieving this end. It begins with postural training and rhythmic breathing associated with preventive measures and auto-therapy or the process of nerve purification. There are numerous kinds of asanas or poses that can be grouped under Meditative and Cultural poses.

Yoga and Health
Yoga has the potential to rejuvenate body-mind complex and re-establish the healthy condition of the practitioner. Through scientific research it has been found that yoga is helpful in controlling several kinds of diseases, such as, hypertension, insomnia, hyperacidity, diabetes, asthma, etc. Yoga is also extremely effective in increasing flexibility, since it acts upon the various joints of the body. It also increases lubrication of the joints, ligaments and tendons. There are different yoga asanas for different systems in the human body as well as diseases.

Benefits of Yoga
Yoga is perhaps the only form of activity which massages all the internal glands and organs of the body in a thorough manner. Yoga acts in a healthy manner on the various body parts. This stimulation and massage of the organs in turn benefits the mass by keeping away diseases. Yoga ensures the optimum blood supply to various parts of the body, by gently stretching muscles and joints as well as massaging the various organs. Regular yoga practice brings about mental clarity and calmness, increases body awareness and also relieves chronic stress patterns, relaxes the mind, centres attention and also sharpens concentration.

Yoga is a complete system that includes practices for body, mind and spirit such as ethics, meditation and physical postures. Yoga strongly believes in balanced state of mind.