The number of asanas used in yoga as exercise has increased rapidly from a nominal 84 in 1830, as illustrated in Joga Pradipika, to some 200 in Light on Yoga and over 900 performed by Dharma Mittra by 1984. At the same time, the goals of Haṭha yoga, namely spiritual liberation (moksha) through the raising of kundalini energy, were largely replaced by the goals of fitness and relaxation, while many of Haṭha yoga's components like the shatkarmas (purifications), mudras (seals or gestures including the bandhas, locks to restrain the prana or vital principle), and pranayama were much reduced or removed entirely. The term "hatha yoga" is also in use with a different meaning, a gentle unbranded yoga practice, independent of the major schools, sometimes mainly for women.
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. The text contains 12 chapters and its origin has been traced to the period between the second century BCE and fourth century CE. 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. The Yoga Yajnavalkya discusses eight yoga Asanas – Swastika, Gomukha, Padma, Vira, Simha, Bhadra, Mukta and Mayura, numerous breathing exercises for body cleansing, and meditation.
Many governments view occupational health as a social challenge and have formed public organizations to ensure the health and safety of workers. Examples of these include the British Health and Safety Executive and in the United States, the National Institute for Occupational Safety and Health, which conducts research on occupational health and safety, and the Occupational Safety and Health Administration, which handles regulation and policy relating to worker safety and health.
What is often referred to as Classical Yoga, Astanga (Yoga of eight limbs), or Raja Yoga is mainly the type of Yoga outlined in the highly influential Yoga Sutras of Patanjali. The origins of the Classical Yoga tradition are unclear, though early discussions of the term appear in the Upanishads. The name "Rāja yoga" (yoga of kings) originally denoted the ultimate goal of yoga, samadhi, but was popularised by Vivekananda as a common name for Ashtanga Yoga,[note 19] the eight limbs to be practised to attain samadhi, as described in the Yoga Sutras. Yoga is also considered as one of the orthodox philosophical schools (darsanas) of Hinduism (those which accept the Vedas as source of knowledge).
Many trainees like to cycle between the two methods in order to prevent the body from adapting (maintaining a progressive overload), possibly emphasizing whichever method more suits their goals; typically, a bodybuilder will aim at sarcoplasmic hypertrophy most of the time but may change to a myofibrillar hypertrophy kind of training temporarily in order to move past a plateau. However, no real evidence has been provided to show that trainees ever reach this plateau, and rather was more of a hype created from "muscular confusion".[clarification needed]