在先前多篇探討耐力運動對抗氧化臨的研究，大多採用老鼠的骨路肌為研究對象，而沒有以人體的骨略肌來進行研究。本篇的研究目的是以人類為受試對象，探討人體骨路肌在椅腳踏車耐力運動的情況下，對於抗氧化峙的影響。受試者為六名男性與二名女性(年齡29.2+ 2.3 ) ，所從事的耐力運動為各人70%V02max的運動強度，騎腳踏車一小時，在進行耐力運動的前後皆從 受試者的股外倒肌抽取骨路肌。然後將抽取到的骨路肌進行過氧化物歧化鷗(SOD)、穀耽甘月太氧化鷗(GPx)、穀耽甘月太還原鷗(GRd)等抗氧化臨的生化 分析。以重複量數t-test'考驗騎腳踏車耐力運動前後的人體骨路肌抗氧化峙的差異情形o結呆顯示，一小時的騎腳踏車耐力運動對於人體骨駱肌的過氧化物歧化鷗、穀耽甘月太過氧化鵲、穀耽甘月太還原鷗等抗氧化鷗皆沒有造成顯著性的差異。由於人體骨路肌的抗氧化時在中強度的騎腳踏車耐力運動下沒有受到影響，於是本研究認為中強度的耐力運動對於人體的骨駱肌可能不會造成氧化壓力(oxidative stress)。

Rat skeletal muscles were studied in most of previous studies concerning the response of endurance exercise on antioxidant enzyme activities， but not human skeletal muscles. Thepurpose of this study was to investigate the effect of cycling endurance exercise on antioxidant enzyme activities in human skeletal muscle. Muscle biopsies were taken from the vastus lateralis of 6 male and 2 female (29.2 + 2.3 yr.) before and after 1 hour cycling endurance exercise at 70% V02max. Theactivities (U/mg protein) of antioxidant enzymes superoxide dismutase (SOD)， glutathione peroxidase (GPx)， and glutathione reductase (GRd) were measured. To determine whether there were significant differences on antioxidant enzyme activities in human skeletal muscle between before and after cycling endurance exercise， repeated t-test was run. Theactivities of SOD， GPx， and GRd all were not significantly changed (p>.05) resulting from cycling endurance exercise. Theseresults indicate that moderate intensity cycling endurance exercise may not cause oxidative stress in human skeletal muscle due to unchanged antioxidant enzyme activities.