Yoga is essentially bodywork. The body is perceived as having 5 layers. They are the physical, energetic, mental (including the 5 senses), wisdom and blissful layers Yoga technology is based on an understanding of how the elements of earth, water, fire, air and ether interact with each layer. At first we learn physical postures. These are called Asana, a sanskrit word meaning ‘comfortable seat’. Asana’s were first practiced by ascetics in the Himalayan mountains of Northern India. The 15th Century Hatha Yoga Pradipika (Light on Hatha Yoga) written by Svatmarama refers to 35 earlier Hatha Yoga masters called Siddha’so. In this Sanskrit manuel he draws from various classic texts from different systems of yoga. He grouped what he found under the generic term ‘Hatha Yoga’ . Hatha Yoga is commonly used now to describe a yoga practice that is predominantly doing postures. This is misleading because Hatha means ‘force’ implying intense ascetic practices.