Tai chi is sometimes described as "meditation in motion" because it promotes serenity through gentle movements — connecting the mind and body. Originally developed in ancient China for self-defense, tai chi evolved into a graceful form of exercise that's now used for stress reduction and to help with a variety of other health conditions. Tai chi, also called tai chi chuan, is a noncompetitive, self-paced system of gentle physical exercise and stretching. To do tai chi, you perform a series of postures or movements in a slow, graceful manner. Each posture flows into the next without pause, ensuring that your body is in constant motion.