Tai chi is a centuries-old Chinese martial art that descends from qigong, an ancient Chinese discipline that has its roots in traditional Chinese medicine. (The people that you see moving gracefully in parks in China are practicing tai chi.) According to some records, tai chi dates back as far as 2,500 years! It involves a series of slow, meditative body movements that were originally designed for self-defense and to promote inner peace and calm. According to the tai chi historian Marvin Smalheiser, some tai chi masters are famous for being able to throw an attacker to the floor with the attacker and spectators unable to clearly see how it was done. Their movements use internal energy and movements too subtle for most people to observe, reflected in the notion that "four ounces can deflect a thousand pounds." At this high level of skill, a defender can use a small amount of energy to neutralize the far greater external force of an attacker.

Yang, wu, and tai chi chih are three of the most popular styles of tai chi. The yang style, which includes 24 movements in its simple form (108 movements in the traditional form), is demanding because you must keep your stance wide and your knees bent most of the time; the wu style, which includes 24 to 36 movements in its shorter form (100 movements in the traditional), is gentler because it uses a narrow, higher stance where the knees are not bent as much as the yang style; and the tai chi chih style, which has 20 movements, also uses a higher stance, but with much less transfer of weight from one leg to the other than the other two. Because the wu style uses a high, narrow stance, it may be easier to do and ideal for improving balance. No matter which style you practice, they all are conducted slowly, deliberately, and gracefully, with each movement flowing seamlessly into the next without hesitation.