To train for Muaythai a fighter must have a mentor. One of the most important virtues of the Thai people is the showing of true respect and sincere humbleness towards teachers, masters, mentors and instructors. They are considered to be second from their true parents. Instructors are full of knowledge, love and kindness, ready and willing to transfer their skill and knowledge to the students, so that the students in turn will be of value to society and to the country as a whole in the future.
The art of Muaythai from past to present has a tradition that every fighter must perform the Wai Kru ritual before every competition. Wai Kru is performed as a means of paying respect to the chairperson of the competition or in the past as a way to pay homage to the King who would normally be a spectator on almost every occasion. It also symbolizes the gratefulness of the fighter towards his mentor who had trained him and as a means of concentrating himself mentally for the competition.
Today, the "Wai Kru ritual" is known as the "Wai Kru" for short. In Muay Thai competition, the art of the Wai Kru ritual is a basic one. It is conducted to pay respect to the instructors, the opponent and the spectators. In reality the effectiveness of the ceremony is to demonstrate the gentleness and graciousness in the controlling of the body and the mind.