In Iran, as of May 2014, according to its Yoga Association, there were approximately 200 yoga centres in the country, a quarter of them in the capital Tehran, where groups can often be seen practising in parks. This has been met by opposition among conservatives.[305] In May 2009, Turkey's head of the Directorate of Religious Affairs, Ali Bardakoğlu, discounted personal development techniques such as reiki and yoga as commercial ventures that could lead to extremism. His comments were made in the context of reiki and yoga possibly being a form of proselytization at the expense of Islam.[306]

Similarly, Brahma sutras – the foundational text of the Vedanta school of Hinduism, discusses yoga in its sutra 2.1.3, 2.1.223 and others.[121] Brahma sutras are estimated to have been complete in the surviving form sometime between 450 BCE to 200 CE,[122][123] and its sutras assert that yoga is a means to gain "subtlety of body" and other powers.[121] The Nyaya sutras – the foundational text of the Nyaya school, variously estimated to have been composed between the 6th-century BCE and 2nd-century CE,[124][125] discusses yoga in sutras 4.2.38–50. This ancient text of the Nyaya school includes a discussion of yogic ethics, dhyana (meditation), samadhi, and among other things remarks that debate and philosophy is a form of yoga.[126][127][128]

^ James Mallinson, "Sāktism and Hathayoga," 28 June 2012. Archived 16 June 2013 at the Wayback Machine [accessed 19 September 2013] pgs. 2 "The earliest references to hathayoga are scattered mentions in Buddhist canonical works and their exegesis dating from the eighth century onwards, in which it is the soteriological method of last resort."

The spiritual sense of the word yoga first arises in Epic Sanskrit, in the second half of the 1st millennium BCE, and is associated with the philosophical system presented in the Yoga Sutras of Patanjali, with the chief aim of "uniting" the human spirit with the Divine.[24] The term kriyāyoga has a technical meaning in the Yoga Sutras (2.1), designating the "practical" aspects of the philosophy, i.e. the "union with the supreme" due to performance of duties in everyday life.[25]