Yoga gurus from India later introduced yoga to the West, following the success of Swami Vivekananda in the late 19th and early 20th century with his adaptation of yoga tradition, excluding asanas. Outside India, it has developed into a form of posture-based physical fitness, stress-relief and relaxation technique. Yoga in Indian traditions, however, is more than physical exercise; it has a meditative and spiritual core. 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.
The Yoga Sutras are also influenced by the Sramana traditions of Buddhism and Jainism, and may represent a further Brahmanical attempt to adopt yoga from the Sramana traditions. As noted by Larson, there are numerous parallels in the concepts in ancient Samkhya, Yoga and Abhidharma Buddhist schools of thought, particularly from 2nd century BCE to 1st century AD. Patanjali's Yoga Sutras is a synthesis of these three traditions. From Samkhya, the Yoga Sutras adopt the "reflective discernment" (adhyavasaya) of prakrti and purusa (dualism), its metaphysical rationalism, as well its three epistemic methods of gaining reliable knowledge. From Abhidharma Buddhism's idea of nirodhasamadhi, suggests Larson, Yoga Sutras adopt the pursuit of altered state of awareness, but unlike Buddhism's concept of no self nor soul, Yoga is physicalist and realist like Samkhya in believing that each individual has a self and soul. The third concept Yoga Sutras synthesize into its philosophy is the ancient ascetic traditions of meditation and introspection, as well as the yoga ideas from middle Upanishads such as Katha, Shvetashvatara and Maitri.
The origins of yoga have been speculated to date back to pre-Vedic Indian traditions; it is mentioned in the Rigveda,[note 1] but most likely developed around the sixth and fifth centuries BCE, in ancient India's ascetic and śramaṇa movements.[note 2] The chronology of earliest texts describing yoga-practices is unclear, varyingly credited to Upanishads. The Yoga Sutras of Patanjali date from the first half of the 1st millennium CE, but only gained prominence in the West in the 20th century. Hatha yoga texts emerged sometimes between the 9th and 11th century with origins in tantra.
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.
The bulking and cutting strategy is effective because there is a well-established link between muscle hypertrophy and being in a state of positive energy balance. A sustained period of caloric surplus will allow the athlete to gain more fat-free mass than they could otherwise gain under eucaloric conditions. Some gain in fat mass is expected, which athletes seek to oxidize in a cutting period while maintaining as much lean mass as possible.
"...[T]here is the cultivation of meditative and contemplative techniques aimed at producing what might, for the lack of a suitable technical term in English, be referred to as 'altered states of consciousness'. In the technical vocabulary of Indian religious texts such states come to be termed 'meditations' ([Skt.:] dhyāna / [Pali:] jhāna) or 'concentrations' (samādhi); the attainment of such states of consciousness was generally regarded as bringing the practitioner to deeper knowledge and experience of the nature of the world." (Gethin, 1998, p. 10.)
According to Zimmer, Yoga philosophy is reckoned to be part of the non-Vedic system, which also includes the Samkhya school of Hindu philosophy, Jainism and Buddhism: "[Jainism] does not derive from Brahman-Aryan sources, but reflects the cosmology and anthropology of a much older pre-Aryan upper class of northeastern India [Bihar] – being rooted in the same subsoil of archaic metaphysical speculation as Yoga, Sankhya, and Buddhism, the other non-Vedic Indian systems."[note 6]
Niyama (The five "observances"): Śauca (purity, clearness of mind, speech and body), Santosha (contentment, acceptance of others and of one's circumstances), Tapas (persistent meditation, perseverance, austerity), Svādhyāya (study of self, self-reflection, study of Vedas), and Ishvara-Pranidhana (contemplation of God/Supreme Being/True Self).
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. Most of the other contemporary yoga systems alluded in the Upanishads and some Buddhist texts are lost to time.[note 12]