為了瞭解不同運動訓練者與體內自由基產生及清除自由基能力的相關性。本研究將受試者分為：對照組(SED；無運動習慣者)、短期運動訓練組(STT；六週體適能訓練者)以及長期運動訓練組(LTT、長期規律運動習慣者)，並利用化學冷光測定不同運動訓練者運動前後體內血漿中超氧自由基含量，同時亦測定血漿中抗氧化酵素活性，如超氧化歧化酶(SOD)、過氧化氫酶(catalase)和穀胱甘肽過氧化酶(glutathione peroxidase；GPx)。本研究發現SED、STT受試者在運動前、後之階段過程中其體內超氧自由基會顯著增加，並達顯著差異水準(P<.05)，同時發現，運動訓練習慣會受試者體內超氧自由基數值下降，並達顯著差異水準。各組在SOD、GPx及catalase活性比較中發現，各組受試者間均達顯著差異水準，但各組受試者在運動階段中並未見顯著差異現象發生，但STT組受試者之抗氧化酵素活性數值明顯高於各組。由此結果我們推測人體施以運動訓練後，訓練初期可能會先提高SOD、catalase和GPx活性以清除體內瞬間大量產生之自由基。但若持續運動訓練一段時間後，體能狀況能改善，進而提升體內之產能效率，減少自由基的產生，以致於抗氧化酵素活性降低。因此，由此可知運動習慣應是持續性和適度的運動，運動不當或過度對人體是毫無助益或適得其反。 In order to elucidate the relationship between ROS homeostasis and physical training, the ROS levels of blood were measured before, during and after a certain physical challenge by the method of chemiluminescence. The intensity of physical challenge is designed to make volunteers reach 85% of maximum heartbeat and sustain till the subject willing to rest. The female volunteers were categorized into three groups. SED Group: as a sedentary subjects group (n=12), STT Group: short term exercise training subjects group (n=11), and LTT Group: long term exercise training group.Our study’s results show that the ROS turnovers of these two groups are quite different during physical challenge. The ROS level seems to be consistent in the group of regular exercise, but increasing in the group of seldom exercise during physical challenge. All volunteers were capable to neutralize ROS after a two-hour rest. In spite of insignificant change in some clinical parameters of blood, the activities of some scavenger enzymes such as SOD、catalase、GPx, seem to be decreased in the group of regular exercise. By comparing before with after 6-weeks-aerobic training, the group of seldom exercise showed decreased but quite similar patterns of the ROS level during physical challenge. Even after 6-weeks training, the ROS level measured before, during and after the physical challenge were still higher than the group of regular exercise.