ABSTRACT: BACKGROUND:To examine the effect of Tai Chi Chuan (TCC) practice on glucose and lipid metabolism and related hormones in TCC practitioners. METHODS:Twenty-one TCC practitioners and nineteen healthy controls were included in this study. Classical Yang's TCC was practiced by the TCC practitioners. The percentage changes in serum total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), serum glucose (SG), serum insulin, serum insulin level, homeostatic model assessment of insulin resistance (HOMA-IR), log(HOMA-IR), quantitative insulin sensitivity check index (QUICKI), and serum endothelin-1 (ET-1) before and 30 min after resting or TCC practice were compared between healthy controls and TCC practitioners. RESULTS:Before TCC or resting, the serum insulin level, HOMA-IR, and log(HOMA-IR) of the TCC practitioners were significantly lower than those of healthy subjects, whereas the QUICKI of the TCC practitioners was significantly higher than that of healthy subjects. Thirty min after TCC practice, the %TC, %HDL-C, %QUICKI, and %ET-1 were all significantly decreased, whereas the %SG, %serum insulin, and %HOMA-IR were significantly increased in the TCC group as compared to the control group 30 min after resting. CONCLUSIONS:The serum glucose, insulin level and insulin resistance were enhanced, whereas the cholesterol, HDL-C and ET-1 levels were reduced 30 min after TCC practice. The mechanism underlying these effects of TCC 30 min after TCC is not clear yet.