Yoga is a group of physical, mental, and spiritual practices or disciplines that originated in ancient India over 5,000 years ago. The spiritual and mythological traditions of India help to fill in the blanks. Yoga was refined and developed by Rishis (sages) who documented their practices and beliefs in the Upanishads, a huge work containing over 200 scriptures. Yoga is amongst the six schools of philosophy in Hinduism, and is also a major part of Buddhism and its meditation practices. The word "yoga" was first mentioned in the oldest sacred texts, the Rig Veda. The practice has been adapted in other countries in a variety of ways, but its origins are in India. Therefore, India pioneered yoga.