激烈運動與自由基、活性氧物種及活性氮物種之生成有密切關聯，當運動後自由基產物之生成與抗氧化防禦機制失衡，將造成氧化壓力，致使肌肉損傷。目的：探討「94年度全國自由車公路錦標賽」對菁英選手抗氧化能力變化與肌肉損傷之影響。方法：受試者為五名男性和五名女性年齡21.4±1.9歲、身高164.4±2.1公分、體重57.6±2.9公斤、身體質量指數21.2±0.6公斤／公尺^2及完成107公里公路賽之平均成績175.7±4.5分（7公里個人計時賽11.8±0.3分，100公里個人公路賽163.4±4.3分）。血液採集共7個時間點：賽前2小時、賽後立即、賽後3小時、賽後7小時、賽後24小時、賽後72小時及賽後120小時。血液樣本分析包括超氧化物歧化酶、麩胱甘肽總量、氧化態麩胱甘肽、肌酸激酶、乳酸脫氫酶、丙二醛、尿酸及一氧化氮。結果：血漿肌酸激酶活性在賽後3小時和7小時分別增加94.3%，91.0%，血漿乳酸脫氫酶活性在賽後7小時和24小時分別增加82.6%，66.2%、紅血球麩胱甘肽總量量在賽後7小時、24小時及72小時分別增加202.9%，185.7%，185.5%；而紅血球氧化態麩胱甘肽量在3小時、7小時、72小時和120小時較賽前分別顯著增加101.7%，133.0%，164.1%，92.2%，但紅血球超氧化物歧化酶活性、血漿丙二醛濃度、尿酸濃度及一氧化氮濃度，在賽後各時間點較賽前並無顯著變化。結論：選手在完成自由車公路賽後短期內可能增加內生性抗氧化物生成。

Purpose: To investigate the effects of road race for elite cyclists on antioxidant capacity and muscle damage. Methods: Ten (five male and five female) elite cyclists (age=21.4±1.9 years; height=164.4±2.1 cm; body mass=57.6±2.9 kg; body mass index (BMI)=21.2±0.6 kg/m^2) were recruited during the 2005 National Cycling Road Race Championship. They spent 175.7±4.5 min (7-Km time trial: 11.8±0.3 min and 100-Km road race: 163.4±4.3 min) to finish the race. The blood samples were collected 2 hours before the race (pre), immediately after the race (0 hr), 3, 7, 24, 72, and 120 hours after the race to determine superoxide dismutase (SOD), total glutathione (TGSH), oxidized glutathione (GSSG), creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), uric acid (UA), and nitric oxide (NO). Results: The plasma CK increased 94.3% and 91.0% significantly at 3 and 7 hours after race and the plasma LDH was significantly increased 82.6% and 66.2% at 7 and 24 hours after race as compared to pre. Meanwhile, the TGSH of erythrocyte was significantly elevated 202.9%, 185.7%, and 185.5% at 7, 24, and 72 hours post race. The GSSG of erythrocyte was significantly elevated 101.7%, 133.0%, 164.1%, and 92.2% at 3, 7, 72, and 120 hours post race. No significant changes were found at the SOD of erythrocyte and the plasma UA, NO, and MDA. Conclusion: A road race may induce endogenous antioxidant production and muscle damage. High intensity exercise induces oxidative stress, but there is no evidence that this affects sports performance in the short term. In this study, we hope that this information may contribute to understand oxidative stress and muscle damages caused by strenuous exercise. The coaches can be inspired to set up the proper training model to promote sports performance. Moreover, this information may also contribute to set up antioxidants supplement or nutrition plans.