Yoga is a union of mind, body, and spirit . The background of yoga is long and also steeped in practice. Yoga exercise is an old system of health and fitness which came from India. The word yoga has its very first reference in the Rig Veda, the oldest of the sacred texts. Those that research Yoga quote its age to be 4 thousand years. The background of Yoga can be split into 4 primary periods which are the pre-classical period, classical duration, post-classical period, and contemporary duration. In the background of yoga, guide is called the yoga sutras. The history of yoga exercise would certainly not have been completed in the classical phase of yoga.