“The principle underlying the system of yoga is that the source of thought, on the one hand, and the source of breathing and vitality on the other is one and the same. In other words, the breath, the life force, the physical body and even the mind – it is nothing more than a form of prana or energy. Therefore, if we effectively manage any of the two, the others will also automatically come under control. Yoga seeks to influence manolaya (state of mind) through pranalaya (state of breath and vital forces) managed and tuned by the practice of pranayama.”
Sri Ramana Maharshi