Yoga gurus from India later introduced yoga to the west, following the success of Swami Vivekananda in the late 19th and early 20th century. In the 1980s, yoga became popular as a system of physical exercise across the Western world. Yoga in Indian traditions, however, is more than physical exercise, it has a meditative and spiritual core. One of the six major orthodox schools of Hinduism is also called Yoga, which has its own epistemology and metaphysics, and is closely related to Hindu Samkhya philosophy.
Many studies have tried to determine the effectiveness of yoga as a complementary intervention for cancer, schizophrenia, asthma, and heart disease. The results of these studies have been mixed and inconclusive, with cancer studies suggesting none to unclear effectiveness, and others suggesting yoga may reduce risk factors and aid in a patient’s psychological healing process.
Yoga, is a meditative means of discovering dysfunctional perception and cognition, as well as overcoming it for release from suffering, inner peace and salvation; illustration of this principle is found in Hindu texts such as the Bhagavad Gita and Yogasutras, in a number of Buddhist Mah?y?na works, as well as Jain texts.