The practice of awakening the coiled energy in the body is sometimes specifically called Kundalini yoga. It is based on Indian theories of the subtle body and uses various pranayamas (breath techniques) and mudras (bodily techniques) to awaken the energy known as kundalini (the coiled one) or shakti. In various Shaiva and Shakta traditions of yoga and tantra, yogic techniques or yuktis are used to unite kundalini-shakti, the divine conscious force or energy, with Shiva, universal consciousness. A common way of teaching this method is to awaken the kundalini residing at the lowest chakra and to guide it through the central channel to unite with the absolute consciousness at the highest chakra (in the top of the head).
If the meaning of yoga is understood as the practice of nirodha (mental control), then its goal is "the unqualified state of niruddha (the perfection of that process)", according to Baba Hari Dass. In that context, "yoga (union) implies duality (as in joining of two things or principles); the result of yoga is the nondual state", and "as the union of the lower self and higher Self. The nondual state is characterized by the absence of individuality; it can be described as eternal peace, pure love, Self-realization, or liberation."
In the early 11th century, the Persian scholar Al Biruni visited India, lived with Hindus for 16 years, and with their help translated several significant Sanskrit works into Arabic and Persian languages. One of these was Patanjali's Yogasutras. Al Biruni's translation preserved many of the core themes of Patañjali 's Yoga philosophy, but certain sutras and analytical commentaries were restated making it more consistent with Islamic monotheistic theology. Al Biruni's version of Yoga Sutras reached Persia and Arabian peninsula by about 1050 AD. Later, in the 16th century, the hath yoga text Amritakunda was translated into Arabic and then Persian. Yoga was, however, not accepted by mainstream Sunni and Shia Islam. Minority Islamic sects such as the mystic Sufi movement, particularly in South Asia, adopted Indian yoga practises, including postures and breath control. Muhammad Ghawth, a Shattari Sufi and one of the translators of yoga text in 16th century, drew controversy for his interest in yoga and was persecuted for his Sufi beliefs.
The earliest references to hatha yoga are in Buddhist works dating from the eighth century. The earliest definition of hatha yoga is found in the 11th century Buddhist text Vimalaprabha, which defines it in relation to the center channel, bindu etc. Hatha yoga synthesizes elements of Patanjali's Yoga Sutras with posture and breathing exercises. It marks the development of asanas (plural) into the full body 'postures' now in popular usage and, along with its many modern variations, is the style that many people associate with the word yoga today.