The effect of Tai Chi on cardiorespiratory function in patients with coronary artery bypass surgery

Purpose: This study prospectively evaluated the training effect of a 1- yr Tai Chi Chuan (TCC) program for low-risk patients with coronary artery bypass surgery (CABS) after a postoperative outpatient (phase II) cardiac rehabilitation program. Methods: Twenty patients with mean age of 56.5 ± 7.4 yr completed this study. The TCC group included nine men who practiced classical Yang TCC with an exercise intensity of 48-57% heart rate range (HRR). The control group included 11 men whom were recommended to do a home- based self-adjusted exercise program with similar intensity of phase II cardiac rehabilitation. Graded exercise tests were performed before and after 1 yr of training for all subjects. Results: Mean attendance of the TCC group was 3.8 ± 1.5 times weekly in contrast to 1.7 ± 1.1 times for the control group. During the follow-up examination, the TCC group increased 10.3% in V?O(2peak) (from 26.2 ± 4.4 to 28.9 ± 5.0 mL · kg-1. min-1, P < 0.01) and increased 11.9% in peak work rate (from 135 ± 26 W to 151 ± 28 W, P < 0.01). However, the control group showed slight decrease in V?O(2peak) from 26.0 ± 3.9 to 25.6 ± 4.6 mL · kg-1 · min-1 and in peak work rate from 131 ± 23 W to 128 ± 32 W. At the ventilatory threshold, the TCC group also showed significant increase in V?O2 and work rate (P < 0.05). The control group did not significantly change in these variables. Conclusions: The study demonstrated that a 1-yr TCC program for low-risk patients with CABS could favorably enhance cardiorespiratory function.