Evidence indicates that low energy expenditure protocols derived from traditional Chinese medicine may benefit patients with cardiac impairment; therefore, the authors carried out a randomized controlled trial to test a 16-week medically assisted qi gong training program for the physical rehabilitation of patients with stable chronic atrial fibrillation and preserved left ventricular function. Functional capacity variation was evaluated using the 6-minute walk test, which was performed at baseline, at the end of the intervention, and after 16 weeks. Thirty men and 13 women (mean age, 68+/-8 years) were randomized to the intervention protocol or to a wait-list control group. Qi gong training was well tolerated and, compared with baseline, trained patients walked an average 114 meters more (27%) at the end of treatment (P<.001) and 57 meters more (13.7%) 16 weeks later (P=.008). Control subjects showed no variation in functional capacity. These results seem promising and deserve confirmation with further research.