^ 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]

The hymns in Book 2 of the Shvetashvatara Upanishad, another late first millennium BCE text, states a procedure in which the body is held in upright posture, the breath is restrained and mind is meditatively focussed, preferably inside a cave or a place that is simple, plain, of silence or gently flowing water, with no noises nor harsh winds.[102][103][100]

During the Gupta period (4th to 5th centuries), a movement of northern Mahāyāna Buddhism termed Yogācāra began to be systematized with the writings of the Buddhist scholars Asanga and Vasubandhu. Yogācāra Buddhism received the name as it provided a "yoga," a systematic framework for engaging in the practices that lead through the path of the bodhisattva towards awakening and full Buddhahood.[169] Its teachings can be found in the comprehensive and encyclopedic work, the Yogācārabhūmi-Śāstra (Treatise on the Foundation for Yoga Practitioners), which was also translated into Tibetan and Chinese and thus exerted a profound influence on the East Asian Buddhist and Tibetan Buddhist traditions.[170] According to Mallinson and Singleton, the study of Yogācāra Buddhism is essential for the understanding of yoga's early history, and its teachings influenced the text of the Pātañjalayogaśāstra.[171]
Niyama (The five "observances"): Śauca (purity, clearness of mind, speech and body),[152] Santosha (contentment, acceptance of others and of one's circumstances),[153] Tapas (persistent meditation, perseverance, austerity),[154] Svādhyāya (study of self, self-reflection, study of Vedas),[155] and Ishvara-Pranidhana (contemplation of God/Supreme Being/True Self).[153]
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.[291][292] 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.[291][293] 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.[294] 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.[295][296] 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.[297]
Although muscle stimulation occurs in the gym (or home gym) when lifting weights, muscle growth occurs afterward during rest periods. Without adequate rest and sleep (6 to 8 hours), muscles do not have an opportunity to recover and grow.[citation needed] Additionally, many athletes find that a daytime nap further increases their body's ability to recover from training and build muscles. Some bodybuilders add a massage at the end of each workout to their routine as a method of recovering.[51]

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.[279] 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).[280]
^ Mangano, Kelsey M.; Sahni, Shivani; Kiel, Douglas P.; Tucker, Katherine L.; Dufour, Alyssa B.; Hannan, Marian T. (February 8, 2017). "Dietary protein is associated with musculoskeletal health independently of dietary pattern: the Framingham Third Generation Study". The American Journal of Clinical Nutrition. 105 (3): 714–722. doi:10.3945/ajcn.116.136762. PMC 5320406. PMID 28179224 – via ajcn.nutrition.org.
Yoga gurus from India later introduced yoga to the West,[15] following the success of Swami Vivekananda in the late 19th and early 20th century with his adaptation of yoga tradition, excluding asanas.[15] Outside India, it has developed into a form of posture-based physical fitness, stress-relief and relaxation technique.[16] Yoga in Indian traditions, however, is more than physical exercise; it has a meditative and spiritual core.[16][17] One of the six major orthodox schools of Hinduism is also called Yoga, which has its own epistemology and metaphysics, and is closely related to Hindu Samkhya philosophy.[18]