The Yoga Yajnavalkya is a classical treatise on yoga attributed to the Vedic sage Yajnavalkya. It takes the form of a dialogue between Yajnavalkya and Gargi, a renowned philosopher.[162] The text contains 12 chapters and its origin has been traced to the period between the second century BCE and fourth century CE.[163] Many yoga texts like the Hatha Yoga Pradipika, the Yoga Kundalini and the Yoga Tattva Upanishads have borrowed verses from or make frequent references to the Yoga Yajnavalkya.[164] The Yoga Yajnavalkya discusses eight yoga Asanas – Swastika, Gomukha, Padma, Vira, Simha, Bhadra, Mukta and Mayura,[165] numerous breathing exercises for body cleansing,[166] and meditation.[167]

There is no consensus on its chronology or specific origin other than that yoga developed in ancient India. Suggested origins are the Indus Valley Civilization (3300–1900 BCE)[44] and pre-Vedic Eastern states of India,[45] the Vedic period (1500–500 BCE), and the śramaṇa movement.[46] According to Gavin Flood, continuities may exist between those various traditions:
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]
*Offer is not available (different pricing applies) in Arkansas, Kentucky, Louisiana, New York (Metro & Premier Plus), Ohio, South Carolina, Tennessee, or Delaware, and does not include access to Signature Clubs or clubs in Canada. Memberships may require an initiation fee and/or annual fee as indicated on membership agreement, except as required by law. Memberships may require commitment to an initial term (except as required by law), in which case an early termination fee will apply if membership agreement is terminated prior to the expiration of the initial term. Single club pricing not available at all locations. Recurring monthly charges must be paid by electronic funds transfer from your checking or savings account or automatic transfer from an accepted credit or debit card. Must be 16 years of age or older (or at least 13 years of age and accompanied by a parent or legal guardian), sign membership agreement, and pay first and last months’ dues and fees for additional services purchased (if any) plus the initiation fee to join. This offer is not available in combination with other discounted rates, coupons or promotions. If offer is advertised as less than $1 per day, that is based on average monthly dues per day in a 30-day month for single club access only. A parent/ legal guardian must sign membership agreement or guest waiver, as applicable, on behalf of members / guests under 18 years of age. Personal training and other services are subject to an additional agreement and requires payment of an additional fee. Offer is subject to change without notice and may end at any time. Additional terms and/or restrictions may apply.
Classical yoga incorporates epistemology, metaphysics, ethical practices, systematic exercises and self-development techniques for body, mind and spirit.[144] Its epistemology (pramana) and metaphysics is similar to that of the Sāṅkhya school. The metaphysics of Classical Yoga, like Sāṅkhya, is mainly dualistic, positing that there are two distinct realities. These are prakriti (nature), which is the eternal and active unconscious source of the material world and is composed of three gunas, and the puruṣas (persons), the plural consciousnesses which are the intelligent principles of the world, and are multiple, inactive and eternal witnesses. Each person has a individual puruṣa, which is their true self, the witness and the enjoyer, and that which is liberated. This metaphysical system holds that puruṣas undergo cycles of reincarnation through its interaction and identification with prakirti. Liberation, the goal of this system, results from the isolation (kaivalya) of puruṣa from prakirti, and is achieved through a meditation which detaches oneself from the different forms (tattvas) of prakirti.[243] This is done by stilling one's thought waves (citta vritti) and resting in pure awareness of puruṣa.
Tantra is a range of esoteric traditions that began to arise in India no later than the 5th century CE.[181][note 17] George Samuel states, "Tantra" is a contested term, but may be considered as a school whose practices appeared in mostly complete form in Buddhist and Hindu texts by about 10th century CE.[183] Tantric yoga developed complex visualizations which included meditation on the body as a microcosm of the cosmos. They included also the use of mantras, pranayama, and the manipulation of the subtle body, including its nadis and cakras. These teachings on cakras and Kundalini would become central to later forms of Indian Yoga.[184]
^ James Mallinson, "Sāktism and Hathayoga," 6 March 2012. PDF file Archived 16 June 2013 at the Wayback Machine [accessed 10 June 2012] pp. 20–21 "The Buddha himself is said to have tried both pressing his tongue to the back of his mouth, in a manner similar to that of the hathayogic khecarīmudrā, and ukkutikappadhāna, a squatting posture which may be related to hathayogic techniques such as mahāmudrā, mahābandha, mahāvedha, mūlabandha, and vajrāsana in which pressure is put on the perineum with the heel, in order to force upwards the breath or Kundalinī."
Carbohydrates play an important role for bodybuilders. They give the body energy to deal with the rigors of training and recovery. Carbohydrates also promote secretion of insulin, a hormone enabling cells to get the glucose they need. Insulin also carries amino acids into cells and promotes protein synthesis.[26] Insulin has steroid-like effects in terms of muscle gains.[27] It is impossible to promote protein synthesis without the existence of insulin, which means that without ingesting carbohydrates or protein—which also induces the release of insulin—it is impossible to add muscle mass.[28] Bodybuilders seek out low-glycemic polysaccharides and other slowly digesting carbohydrates, which release energy in a more stable fashion than high-glycemic sugars and starches. This is important as high-glycemic carbohydrates cause a sharp insulin response, which places the body in a state where it is likely to store additional food energy as fat. However, bodybuilders frequently do ingest some quickly digesting sugars (often in form of pure dextrose or maltodextrin) just before, during, and/or just after a workout. This may help to replenish glycogen stored within the muscle, and to stimulate muscle protein synthesis.[29]
If you have high blood pressure, diabetes, or heart problems, ask your doctor what you can do. You may need to avoid certain postures, like those in which you're upside down or that demand more balance than you have right now. A very gentle program of yoga, coupled with a light aerobic activity like walking or swimming, may be the best way to start.

^ 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]

Systematic activities to prevent or cure health problems and promote good health in humans are undertaken by health care providers. Applications with regard to animal health are covered by the veterinary sciences. The term "healthy" is also widely used in the context of many types of non-living organizations and their impacts for the benefit of humans, such as in the sense of healthy communities, healthy cities or healthy environments. In addition to health care interventions and a person's surroundings, a number of other factors are known to influence the health status of individuals, including their background, lifestyle, and economic, social conditions and spirituality; these are referred to as "determinants of health." Studies have shown that high levels of stress can affect human health.[15]