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

Abstract

The effect of Tai Chi on cardiorespiratory function in patients with coronary artery bypass surgery. Med. Sci. Sports Exerc., Vol. 31, No. 5, pp. 634-638, 1999. 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. 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. 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 O2peak (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 O2peak 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 O2 and work rate (P < 0.05). The control group did not significantly change in these variables. The study demonstrated that a 1-yr TCC program for low-risk patients with CABS could favorably enhance cardiorespiratory function.