The ancient Chinese form of exercise combines meditation with slow, gentle movements, deep breathing and relaxation. It can improve muscle strength, balance, sleep, and coordination.
Fibromyalgia is most common in middle-aged women. Its cause is unknown.
The study at Tufts University School of Medicine involved 66 patients. They were assigned to try tai chi or wellness education and stretching exercises for 12 weeks.
Symptoms of the illness improved significantly for the tai chi group and little for the others.
The results are in Thursday's New England Journal of Medicine.
