Public health also takes various actions to limit the health disparities between different areas of the country and, in some cases, the continent or world. One issue is the access of individuals and communities to health care in terms of financial, geographical or socio-cultural constraints to accessing and using services. Applications of the public health system include the areas of maternal and child health, health services administration, emergency response, and prevention and control of infectious and chronic diseases.
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) and pre-Vedic Eastern states of India, the Vedic period (1500–500 BCE), and the śramaṇa movement. According to Gavin Flood, continuities may exist between those various traditions:
Sandow was so successful at flexing and posing his physique that he later created several businesses around his fame, and was among the first to market products branded with his name. He was credited with inventing and selling the first exercise equipment for the masses: machined dumbbells, spring pulleys, and tension bands. Even his image was sold by the thousands in "cabinet cards" and other prints. Sandow was a perfect "Gracilian", a standard of ideal body proportions close to those of ancient Greek and Roman statues. Men's physiques were then judged by how closely they matched these proportions.
Site enhancement oil, often called "santol" or "synthol" (no relation to the Synthol mouthwash brand), refers to oils injected into muscles to increase the size or change the shape. Some bodybuilders, particularly at the professional level, inject their muscles with such mixtures to mimic the appearance of developed muscle where it may otherwise be disproportionate or lacking. This is known as "fluffing". Synthol is 85% oil, 7.5% lidocaine, and 7.5% alcohol. It is not restricted, and many brands are available on the Internet. The use of injected oil to enhance muscle appearance is common among bodybuilders, despite the fact that synthol can cause pulmonary embolisms, nerve damage, infections, sclerosing lipogranuloma, stroke, and the formation of oil-filled granulomas, cysts or ulcers in the muscle. Rare cases might require surgical intervention to avoid further damage to the muscle and/or to prevent loss of life.
Śaradatilaka of Lakshmanadesikendra, a Shakta Tantra work 11th century CE "Yogic experts state that yoga is the oneness of the individual soul (jiva) with the atman. Others understand it to be the ascertainment of Siva and the soul as non-different. The scholars of the Agamas say that it is a Knowledge which is of the nature of Siva’s Power. Other scholars say it is the knowledge of the primordial soul." (SaTil 25.1–3b)
Public health has been described as "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals." It is concerned with threats to the overall health of a community based on population health analysis. The population in question can be as small as a handful of people or as large as all the inhabitants of several continents (for instance, in the case of a pandemic). Public health has many sub-fields, but typically includes the interdisciplinary categories of epidemiology, biostatistics and health services. Environmental health, community health, behavioral health, and occupational health are also important areas of public health.
An article by Muscle & Fitness magazine, "Overtrain for Big Gains", claimed that overtraining for a brief period can be beneficial. Overtraining can be used advantageously, as when a bodybuilder is purposely overtrained for a brief period of time to super compensate during a regeneration phase. These are known as "shock micro-cycles" and were a key training technique used by Soviet athletes.
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. Brahma sutras are estimated to have been complete in the surviving form sometime between 450 BCE to 200 CE, and its sutras assert that yoga is a means to gain "subtlety of body" and other powers. 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, 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.
The motor proteins actin and myosin generate the forces exerted by contracting muscles. Current recommendations suggest that bodybuilders should consume 25–30% of protein per total calorie intake to further their goal of maintaining and improving their body composition. This is a widely debated topic, with many arguing that 1 gram of protein per pound of body weight per day is ideal, some suggesting that less is sufficient, while others recommending 1.5, 2, or more. It is believed that protein needs to be consumed frequently throughout the day, especially during/after a workout, and before sleep. There is also some debate concerning the best type of protein to take. Chicken, turkey, beef, pork, fish, eggs and dairy foods are high in protein, as are some nuts, seeds, beans, and lentils. Casein or whey are often used to supplement the diet with additional protein. Whey protein is the type of protein contained in many popular brands of protein supplements and is preferred by many bodybuilders because of its high Biological Value (BV) and quick absorption rates. Whey protein also has a bigger effect than casein on insulin levels, triggering about double the amount of insulin release. That effect is somewhat overcome by combining casein and whey. Bodybuilders are usually thought to require protein with a higher BV than that of soy, which is additionally avoided due to its claimed estrogenic properties. Still, some nutrition experts believe that soy, flax seeds and many other plants that contain the weak estrogen-like compounds or phytoestrogens, can be used beneficially, as phytoestrogens compete with estrogens for receptor sites in the male body and can block its actions. This can also include some inhibition of pituitary functions while stimulating the P450 system (the system that eliminates hormones, drugs and metabolic waste product from the body) in the liver to more actively process and excrete excess estrogen. Cortisol decreases amino acid uptake by muscle, and inhibits protein synthesis.
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]
Focusing more on lifestyle issues and their relationships with functional health, data from the Alameda County Study suggested that people can improve their health via exercise, enough sleep, spending time in nature, maintaining a healthy body weight, limiting alcohol use, and avoiding smoking. Health and illness can co-exist, as even people with multiple chronic diseases or terminal illnesses can consider themselves healthy.