During the period between the Mauryan and the Gupta eras (c. 200 BCE–500 CE) the Indic traditions of Hinduism, Buddhism and Jainism were taking form and coherent systems of yoga began to emerge. This period witnessed many new texts from these traditions discussing and systematically compiling yoga methods and practices. Some key works of this era include the Yoga Sūtras of Patañjali, the Yoga-Yājñavalkya, the Yogācārabhūmi-Śāstra and the Visuddhimagga.
Health science is the branch of science focused on health. There are two main approaches to health science: the study and research of the body and health-related issues to understand how humans (and animals) function, and the application of that knowledge to improve health and to prevent and cure diseases and other physical and mental impairments. The science builds on many sub-fields, including biology, biochemistry, physics, epidemiology, pharmacology, medical sociology. Applied health sciences endeavor to better understand and improve human health through applications in areas such as health education, biomedical engineering, biotechnology and public health.
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.)
According to Tattvarthasutra, 2nd century CE Jain text, yoga is the sum of all the activities of mind, speech and body. Umasvati calls yoga the cause of "asrava" or karmic influx as well as one of the essentials—samyak caritra—in the path to liberation. In his Niyamasara, Acarya Kundakunda, describes yoga bhakti—devotion to the path to liberation—as the highest form of devotion. Acarya Haribhadra and Acarya Hemacandra mention the five major vows of ascetics and 12 minor vows of laity under yoga. This has led certain Indologists like Prof. Robert J. Zydenbos to call Jainism, essentially, a system of yogic thinking that grew into a full-fledged religion. The five yamas or the constraints of the Yoga Sutras of Patanjali bear a resemblance to the five major vows of Jainism, indicating a history of strong cross-fertilization between these traditions.[note 16]
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.
^ Mann, T; Tomiyama, AJ; Westling, E; Lew, AM; Samuels, B; Chatman, J (April 2007). "Medicare's search for effective obesity treatments: diets are not the answer". The American Psychologist. 62 (3): 220–33. CiteSeerX 10.1.1.666.7484. doi:10.1037/0003-066x.62.3.220. PMID 17469900. In sum, there is little support for the notion that diets ["severely restricting one’s calorie intake"] lead to lasting weight loss or health benefits.
^ * Wynne states that "The Nasadiyasukta, one of the earliest and most important cosmogonic tracts in the early Brahminic literature, contains evidence suggesting it was closely related to a tradition of early Brahminic contemplation. A close reading of this text suggests that it was closely related to a tradition of early Brahminic contemplation. The poem may have been composed by contemplatives, but even if not, an argument can be made that it marks the beginning of the contemplative/meditative trend in Indian thought."
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.
"...[T]here is the cultivation of meditative and contemplative techniques aimed at producing what might, for the lack of a suitable technical term in English, be referred to as 'altered states of consciousness'. In the technical vocabulary of Indian religious texts such states come to be termed 'meditations' ([Skt.:] dhyāna / [Pali:] jhāna) or 'concentrations' (samādhi); the attainment of such states of consciousness was generally regarded as bringing the practitioner to deeper knowledge and experience of the nature of the world." (Gethin, 1998, p. 10.)
Prolonged psychological stress may negatively impact health, and has been cited as a factor in cognitive impairment with aging, depressive illness, and expression of disease. Stress management is the application of methods to either reduce stress or increase tolerance to stress. Relaxation techniques are physical methods used to relieve stress. Psychological methods include cognitive therapy, meditation, and positive thinking, which work by reducing response to stress. Improving relevant skills, such as problem solving and time management skills, reduces uncertainty and builds confidence, which also reduces the reaction to stress-causing situations where those skills are applicable.