Muscle growth is more difficult to achieve in older adults than younger adults because of biological aging, which leads to many metabolic changes detrimental to muscle growth; for instance, by diminishing growth hormone and testosterone levels. Some recent clinical studies have shown that low-dose HGH treatment for adults with HGH deficiency changes the body composition by increasing muscle mass, decreasing fat mass, increasing bone density and muscle strength, improves cardiovascular parameters, and affects the quality of life without significant side effects.[unreliable medical source?]
Another text which teaches yoga with an Advaita point of view is the Yoga-Yājñavalkya. This work contains extensive teachings on ten Yamas (ethical rules) and ten Niyamas (duties), and eight asanas. It also discusses a theory of nadis and prana (vital breath), and follows this with instructions on pranayama (breath control), pratyahara (sense withdrawal), meditation on mantras, meditative visualizations and Kundalini.
According to Geoffrey Samuel, our "best evidence to date" suggests that yogic practices "developed in the same ascetic circles as the early śramaṇa movements (Buddhists, Jainas and Ajivikas), probably in around the sixth and fifth centuries BCE." This occurred during what is called the ‘Second Urbanisation’ period. According to Mallinson and Singleton, these traditions were the first to use psychophysical techniques, mainly known as dhyana and tapas. but later described as yoga, to strive for the goal of liberation (moksha, nirvana) from samsara (the round of rebirth).
The Maitrayaniya Upanishad, likely composed in a later century than Katha and Shvetashvatara Upanishads but before Patanjali's Yoga Sutra, mentions sixfold yoga method – breath control (pranayama), introspective withdrawal of senses (pratyahara), meditation (dhyana), mind concentration (dharana), philosophical inquiry/creative reasoning (tarka), and absorption/intense spiritual union (samadhi).
Modern yoga was created in what has been called the Modern Yoga Renaissance by the blending of Western styles of gymnastics with postures from Haṭha yoga in India in the 20th century, pioneered by Shri Yogendra and Swami Kuvalayananda. Before 1900 there were few standing poses in Haṭha yoga. The flowing sequences of salute to the sun, Surya Namaskar, were pioneered by the Rajah of Aundh, Bhawanrao Shrinivasrao Pant Pratinidhi, in the 1920s. Many standing poses used in gymnastics were incorporated into yoga by Krishnamacharya in Mysore from the 1930s to the 1950s. Several of his students went on to found influential schools of yoga: Pattabhi Jois created Ashtanga Vinyasa Yoga, which in turn led to Power Yoga; B. K. S. Iyengar created Iyengar Yoga, and systematised the canon of asanas in his 1966 book Light on Yoga; Indra Devi taught yoga to many film stars in Hollywood; and Krishnamacharya's son T. K. V. Desikachar founded the Krishnamacharya Yoga Mandalam in Chennai. Other major schools founded in the 20th century include Bikram Choudhury's Bikram Yoga and Swami Sivananda of Rishikesh's Sivananda Vedanta Schools of Yoga. Modern yoga spread across America and Europe, and then the rest of the world.
Bodybuilding is the use of progressive resistance exercise to control and develop one's musculature for aesthetic purposes. An individual who engages in this activity is referred to as a bodybuilder. In competitive bodybuilding, bodybuilders appear in lineups and perform specified poses (and later individual posing routines) for a panel of judges who rank the competitors based on criteria such as symmetry, muscularity, and conditioning. Bodybuilders prepare for competitions through the elimination of nonessential body fat, enhanced at the last stage by a combination of extracellular dehydration and carbohydrate loading, to achieve maximum muscular definition and vascularity, as well as tanning to accentuate the contrast of the skin under the spotlights. Bodybuilders may use anabolic steroids and other performance-enhancing drugs to build muscles.