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. 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.
Ascetic practices (tapas), concentration and bodily postures used by Vedic priests to conduct yajna (sacrifice), might have been precursors to yoga.[note 9] Vratya, a group of ascetics mentioned in the Atharvaveda, emphasized on bodily postures which may have evolved into yogic asanas. Early Samhitas also contain references to other group ascetics such as munis, the keśin, and vratyas. Techniques for controlling breath and vital energies are mentioned in the Brahmanas (texts of the Vedic corpus, c. 1000–800 BCE) and the Atharvaveda. Nasadiya Sukta of the Rig Veda suggests the presence of an early contemplative tradition.[note 10]
^ "application or concentration of the thoughts, abstract contemplation, meditation , (esp.) self-concentration, abstract meditation and mental abstraction practised as a system (as taught by Patañjali and called the yoga philosophy; it is the second of the two sāṃkhya systems, its chief aim being to teach the means by which the human spirit may attain complete union with īśvara or the Supreme Spirit; in the practice of self-concentration it is closely connected with Buddhism". Monier-Williams, A Sanskrit Dictionary (1899)
Genetics, or inherited traits from parents, also play a role in determining the health status of individuals and populations. This can encompass both the predisposition to certain diseases and health conditions, as well as the habits and behaviors individuals develop through the lifestyle of their families. For example, genetics may play a role in the manner in which people cope with stress, either mental, emotional or physical. For example, obesity is a significant problem in the United States that contributes to bad mental health and causes stress in the lives of great numbers of people. (One difficulty is the issue raised by the debate over the relative strengths of genetics and other factors; interactions between genetics and environment may be of particular importance.)
Alexander Wynne observes that formless meditation and elemental meditation might have originated in the Upanishadic tradition. The earliest reference to meditation is in the Brihadaranyaka Upanishad, one of the oldest Upanishads. 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. Taittiriya Upanishad defines yoga as the mastery of body and senses.
^ World Health Organization.Constitution of the World Health Organization as adopted by the International Health Conference, New York, 19–22 June 1946; signed on 22 July 1946 by the representatives of 61 States (Official Records of the World Health Organization, no. 2, p. 100) and entered into force on 7 April 1948. In Grad, Frank P. (2002). "The Preamble of the Constitution of the World Health Organization". Bulletin of the World Health Organization. 80 (12): 982.