Numerous studies have evaluated the effects of Tai Chi on cardiovascular and respiratory function. Since 1993, three observational studies and 2 NRSs were conducted by Taiwan groups to evaluate the cardiovascular effect of regular Tai Chi practice. Two cohort studies of 90 and 84 subjects with 6.3 and 6.7 years’ experience of Tai Chi, respectively, were reported. Cardiopulmonary exercise testing using incremental cycle ergometry and HR measurements were performed in these studies. The researchers found that the oxygen uptake ( O2 and work rate in the Tai Chi group were significantly higher than in the control group. Tai Chi practitioners had a smaller decline in the maximum oxygen uptake than their sedentary counterparts.
One case control study of 76 subjects with 11.8 years of Tai Chi practice (mean age, 69 years) evaluated cardiovascular function, flexibility, and body composition. The researchers found that the long-term Tai Chi practitioners showed higher O2 scores in the stand-and-reach test and a lower percentage of body fat than their sedentary counterparts. Two NRSs evaluated the training effect of Tai Chi for 38 community-dwelling subjects (aged 58-70 years) and 20 low-risk patients who underwent coronary artery bypass surgery (mean age, 57 years). After 1 year of 4-times-weekly Tai Chi training, the Tai Chi group showed significantly enhanced cardiorespiratory function, strength and flexibility, and increased O2 and work rate compared with the control group who performed self-adjusted exercises.
One NRS37 with 20 subjects (aged 30-35 years) examined the metabolic and cardiorespiratory responses to continuous performance of Tai Chi and Wing Chun (rapid forceful striking and kicking movements with forced expirations timed with punching and kicking in an attempt to achieve maximum power). The exercise values corresponded to 52.4% of maximum oxygen uptake values ( O2max) and 70.5% of maximum HR (HRmax) for Wing Chun and only 36.4% of O2max and 59.8% of HRmax for Tai Chi. The ventilatory equivalent for O2 obtained during Tai Chi (21.7) was significantly lower than for Wing Chun exercise (24.2). The authors concluded that Tai Chi practitioners use efficient breathing patterns during exercise. However, because Tai Chi is a low- to moderate-intensity form of exercise, it might not be suitable for improving cardiorespiratory fitness.
Results related to the effect of Tai Chi on cardiovascular and pulmonary function have been reported in 11 publications by Chinese researchers since 1979.38-48 Although 1 study40 reported that the metabolic intensity of the activity seemed insufficient to generate improvements of cardiorespiratory fitness in healthy young adults, all other studies suggested that regularly practiced Tai Chi might delay the decline of cardiorespiratory function in older individuals and might be prescribed as a suitable exercise for older adults.
No RCTs were identified in this area, and the overall study quality was very poor, especially among the studies conducted in China. Many limitations were found in the Chinese studies, such as unclear study designs, small sample sizes, poorly reported baseline health status and eligibility criteria of the subjects, lack of comparison groups, lack of detailed information about the types of Tai Chi exercise and duration of the trial, lack of accounting of subjects lost to follow-up, and no blinding of outcome assessors.38-48 In addition, study limitations included potential selection bias, confounding factors, inconsistent measurement intervals, and large differences in Tai Chi practitioner experience.
