Yoga has been defined by Patanjali, the renowned author of the Yoga Darshana, as ‘the control of the functions of the mind’. The mind is a part of our subtle body which has a direct bearing on the gross body. Hence in Yoga we take both mind and body together in all our practices and even so in the selection of the diet. The subtle and the gross are regarded as one entity. A Yogi literally accepts the maxim ‘sound mind in a sound body’ and also the contrary. He agrees with the remarks of the Sanskrit poet Kalidasa that the body is the first requisite of the fulfillment of Dharma i.e. path of virtue, and also endorses the views of Lord Krishna expressed in the Shrimad-Bhagvad-Gita that ‘Yoga results in the efficiency of actions’.
Actions can be performed more efficiently when both mind and body are sound and in perfect health. Consequently, in Yoga, a Yogi practices to develop and control both his body and mind. In the science of Yoga, these are separately dealt under the two principle branches – Hath Yoga and Raj Yoga. Hath yoga involves the seven fold Sadhana or practices for mental and physical soundness or physico-mental perfection. Raj Yoga, the so called Ashtang Yoga involves the eight fold Sadhana.