The primary purpose of this study was to examine the metabolic and cardiorespiratory responses to the continuous performance of Wing Chun and T'ai Chi Chuan exercise. No significant differences in VO2max or HRmax obtained during treadmill exercise were found between the practitioners of the two styles. Average values for oxygen uptake (VO2) were 23.3 +/- 7.5 ml.kg-1.min-1 (6.6 METS) and 16.0 +/- 3.9 ml.kg-1.min-1 (4.6 METS) for Wing Chun and T'ai Chi Chuan exercise, respectively. Mean heart rates obtained during exercise were 137 +/- 25 beats.min-1 for Wing Chun and 116 +/- 22 beats.min-1 for T'ai Chi Chuan exercise. These exercise values corresponded to 52.4% of VO2max and 70.5% of HRmax for Wing Chun and only 36.4% of VO2max and 59.8% of HRmax for T'ai Chi Chuan exercise. Thus, only the continuous performance of Wing Chun exercise elicited VO2 and HR responses that would be expected to bring about a cardiorespiratory training effect in subjects with a relatively low initial VO2max. The ventilatory equivalent for oxygen (VE/VO2) obtained during T'ai Chi Chuan exercise (21.7) was significantly lower than for Wing Chun exercise (24.2), suggesting that T'ai Chi practitioners utilize efficient breathing patterns during exercise. Both Wing Chun and T'ai Chi Chuan styles may have a small static component that produces a slightly elevated heart rate relative to metabolic load when compared to traditional aerobic activities. However, the effect was not severe and these forms of exercise should not be considered dangerous for individuals at high risk for cardiovascular disease.