Purification is a central aim of all yogic practices, as the ancient yogis believed that impurities in our internal body adversely affect our state of mind and prevent the attainment of true contentment. And kriyas—yoga techniques designed to cleanse the body, mind, and emotions—have far-reaching relevance in today's society of over-consumption. Focusing on each of the five senses, Swami Saradananda includes yoga poses as well as breathing exercises, mantras, and cleansing chakra visualizations.