Pre-philosophical speculations of yoga begin to emerge in the texts of c. 500 – c. 200 BCE. Between 200 BCE and 500 CE, philosophical schools of Hinduism, Buddhism, and Jainism were taking form and a coherent philosophical system of yoga began to emerge.[50] The Middle Ages saw the development of many satellite traditions of yoga. Yoga came to the attention of an educated western public in the mid 19th century along with other topics of Indian philosophy.
Various yogic groups had become prominent in Punjab in the 15th and 16th century, when Sikhism was in its nascent stage. Compositions of Guru Nanak, the founder of Sikhism, describe many dialogues he had with Jogis, a Hindu community which practiced yoga. Guru Nanak rejected the austerities, rites and rituals connected with Hatha Yoga. He propounded the path of Sahaja yoga or Nama yoga (meditation on the name) instead.[201] The Guru Granth Sahib states:
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.[278] 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).[279]
Some Christians integrate yoga and other aspects of Eastern spirituality with prayer and meditation. This has been attributed to a desire to experience God in a more complete way.[280] In 2013, Monsignor Raffaello Martinelli, servicing Congregation for the Doctrine of the Faith, having worked for over 23 years with Cardinal Joseph Ratzinger (Pope Benedict XVI),[281] said that for his Meditation, a Christian can learn from other religious traditions (zen, yoga, controlled respiration, Mantra), quoting Aspects of Christian meditation: "Just as "the Catholic Church rejects nothing of what is true and holy in these religions," neither should these ways be rejected out of hand simply because they are not Christian. On the contrary, one can take from them what is useful so long as the Christian conception of prayer, its logic and requirements are never obscured. It is within the context of all of this that these bits and pieces should be taken up and expressed anew."[282] Previously, the Roman Catholic Church, and some other Christian organizations have expressed concerns and disapproval with respect to some eastern and New Age practices that include yoga and meditation.[283][284][285]
Jain yoga has been a central practice in Jainism. Jain spirituality is based on a strict code of nonviolence or ahimsa (which includes vegetarianism), almsgiving (dana), right faith in the three jewels, the practice of austerities (tapas) such as fasting, and yogic practices.[249][250] Jain yoga aims at the liberation and purification of the self (atma) or soul (jiva) from the forces of karma, which keep all souls bound to the cycle of transmigration. Like Yoga and Sankhya, Jainism believes in a multiplicity of individual souls which bound by their individual karma.[251] Only through the reduction of karmic influxes and the exhaustion of one's collected karma can a soul become purified and released, at which point one becomes an omniscient being who has reaches "absolute knowledge" (kevala jnana).[252]

Site enhancement oil, often called "santol" or "synthol" (no relation to the Synthol mouthwash brand), refers to oils injected into muscles to increase the size or change the shape. Some bodybuilders, particularly at the professional level, inject their muscles with such mixtures to mimic the appearance of developed muscle where it may otherwise be disproportionate or lacking.[55] This is known as "fluffing".[56][57] Synthol is 85% oil, 7.5% lidocaine, and 7.5% alcohol.[56] It is not restricted, and many brands are available on the Internet.[58] The use of injected oil to enhance muscle appearance is common among bodybuilders,[59][60] despite the fact that synthol can cause pulmonary embolisms, nerve damage, infections, sclerosing lipogranuloma,[61] stroke,[56] and the formation of oil-filled granulomas, cysts or ulcers in the muscle.[60][62][63] Rare cases might require surgical intervention to avoid further damage to the muscle and/or to prevent loss of life.[64]