Alexander Wynne observes that formless meditation and elemental meditation might have originated in the Upanishadic tradition.[93] The earliest reference to meditation is in the Brihadaranyaka Upanishad, one of the oldest Upanishads.[67] Chandogya Upanishad describes the five kinds of vital energies (prana). Concepts used later in many yoga traditions such as internal sound and veins (nadis) are also described in the Upanishad.[59] Taittiriya Upanishad defines yoga as the mastery of body and senses.[94]
A yoga system that predated the Buddhist school is Jain yoga. But since Jain sources postdate Buddhist ones, it is difficult to distinguish between the nature of the early Jain school and elements derived from other schools.[89] Most of the other contemporary yoga systems alluded in the Upanishads and some Buddhist texts are lost to time.[90][91][note 12]

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)",[147] 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."[148]
^ James Mallinson, "Sāktism and Hathayoga," 6 March 2012. PDF file Archived 16 June 2013 at the Wayback Machine [accessed 10 June 2012] pp. 20–21 "The Buddha himself is said to have tried both pressing his tongue to the back of his mouth, in a manner similar to that of the hathayogic khecarīmudrā, and ukkutikappadhāna, a squatting posture which may be related to hathayogic techniques such as mahāmudrā, mahābandha, mahāvedha, mūlabandha, and vajrāsana in which pressure is put on the perineum with the heel, in order to force upwards the breath or Kundalinī."
Personal health depends partially on the active, passive, and assisted cues people observe and adopt about their own health. These include personal actions for preventing or minimizing the effects of a disease, usually a chronic condition, through integrative care. They also include personal hygiene practices to prevent infection and illness, such as bathing and washing hands with soap; brushing and flossing teeth; storing, preparing and handling food safely; and many others. The information gleaned from personal observations of daily living – such as about sleep patterns, exercise behavior, nutritional intake and environmental features – may be used to inform personal decisions and actions (e.g., "I feel tired in the morning so I am going to try sleeping on a different pillow"), as well as clinical decisions and treatment plans (e.g., a patient who notices his or her shoes are tighter than usual may be having exacerbation of left-sided heart failure, and may require diuretic medication to reduce fluid overload).[57]
^ Werner writes, "The word Yoga appears here for the first time in its fully technical meaning, namely as a systematic training, and it already received a more or less clear formulation in some other middle Upanishads....Further process of the systematization of Yoga as a path to the ultimate mystic goal is obvious in subsequent Yoga Upanishads and the culmination of this endeavour is represented by Patanjali's codification of this path into a system of the eightfold Yoga."[138]
Theosophists including Madame Blavatsky also had a large influence on the Western public's view of Yoga.[207] Esoteric views current at the end of the 19th century provided a further basis for the reception of Vedanta and of Yoga with its theory and practice of correspondence between the spiritual and the physical.[208] The reception of Yoga and of Vedanta thus entwined with each other and with the (mostly Neoplatonism-based) currents of religious and philosophical reform and transformation throughout the 19th and early 20th centuries. Mircea Eliade brought a new element into the reception of Yoga with the strong emphasis on Tantric Yoga in his seminal book: Yoga: Immortality and Freedom.[209] With the introduction of the Tantra traditions and philosophy of Yoga, the conception of the "transcendent" to be attained by Yogic practice shifted from experiencing the "transcendent" ("Atman-Brahman" in Advaitic theory) in the mind to the body itself.[210]
The Yoga Yajnavalkya is a classical treatise on yoga attributed to the Vedic sage Yajnavalkya. It takes the form of a dialogue between Yajnavalkya and Gargi, a renowned philosopher.[162] The text contains 12 chapters and its origin has been traced to the period between the second century BCE and fourth century CE.[163] Many yoga texts like the Hatha Yoga Pradipika, the Yoga Kundalini and the Yoga Tattva Upanishads have borrowed verses from or make frequent references to the Yoga Yajnavalkya.[164] The Yoga Yajnavalkya discusses eight yoga Asanas – Swastika, Gomukha, Padma, Vira, Simha, Bhadra, Mukta and Mayura,[165] numerous breathing exercises for body cleansing,[166] and meditation.[167]
Vajrayana is also known as Tantric Buddhism and Tantrayāna. Its texts were compiled starting with 7th century and Tibetan translations were completed in 8th century CE. These tantra yoga texts were the main source of Buddhist knowledge that was imported into Tibet.[185] They were later translated into Chinese and other Asian languages, helping spread ideas of Tantric Buddhism. The Buddhist text Hevajra Tantra and Caryāgiti introduced hierarchies of chakras.[186] Yoga is a significant practice in Tantric Buddhism.[187][188][189]

In 2009, the Council of Ulemas, an Islamic body in Indonesia, passed a fatwa banning yoga on the grounds that it contains Hindu elements.[302] These fatwas have, in turn, been criticized by Darul Uloom Deoband, a Deobandi Islamic seminary in India.[303] Similar fatwas banning yoga, for its link to Hinduism, were issued by the Grand Mufti Ali Gomaa in Egypt in 2004, and by Islamic clerics in Singapore earlier.[304]
One of the best known early expressions of Brahmanical Yoga thought is the Yoga Sutras of Patanjali , the original name of which may have been the Pātañjalayogaśāstra-sāṃkhya-pravacana (c. sometime between 325 - 425) which some scholars now believe included both the sutras and a commentary.[129] As the name suggests, the metaphysical basis for this text is the Indian philosophy termed Sāṃkhya. This atheistic school is mentioned in Kauṭilya's Arthashastra as one of the three categories of anviksikis (philosophies) along with Yoga and Cārvāka.[130][131] The two schools have some differences as well. Yoga accepted the conception of "personal god", while Samkhya developed as a rationalist, non-theistic/atheistic system of Hindu philosophy.[132][133][134] Sometimes Patanjali's system is referred to as Seshvara Samkhya in contradistinction to Kapila's Nirivara Samkhya.[135] The parallels between Yoga and Samkhya were so close that Max Müller says that "the two philosophies were in popular parlance distinguished from each other as Samkhya with and Samkhya without a Lord."[136]