目的：本研究目的在探討女性在不同月經週期中在高強度運動後氧化壓力與肌肉損傷對運動表現之影響。方法：本研究招募9位具規律月經週期之健康大專女性，以平衡次序法，分為濾泡中期和黃體中期兩組。受試者於濾泡中期和黃體中期，利用原地固定式腳踏車進行高強度運動，以15W暖身3分鐘，之後每分鐘增加15W，維持在60rpm以上，直至力竭，並在運動前、後及運動後24小時進行採血，分析肌酸激酶（creatine kinase, CK）、超氧化物歧化酶（superoxide dismutase, SOD）、丙二醛（malondialdehyde, MDA）濃度之變化，並紀錄最大攝氧量（VO2max）、心跳（heart rate, HR）、血乳酸（lactic acid, LA）與總運動時間。結果：血液中CK、SOD濃度在不同月經週期中，運動前、後與運動後24小時並無顯著差異（p > .05）；在運動表現方面，受試者在不同月經週期中，其VO2max、HR與LA並沒有顯著差異，但在力竭時間方面顯示，濾泡中期顯著少於黃體中期（690.67 ± 89.42 vs. 695.22 101.69 秒 p < .05）。結論：因此女性在不同月經週期中，黃體中期可能有益於運動力竭時間表現，但在力竭運動後對於氧化壓力與肌肉損傷都不影響。

Purpose: The purpose of this study was to investigate the effect of menstrual cycle on performance, lipid peroxidation, and muscle damage after exhaustive exercise. Methods: Nine females with regular menstrual cycle participated in this research. The subjects preformed the incremental bicycle ergometer test until exhaustion at a constant pedal speed of 60 rpm with stepwise increment of 15W every minute after a warm-up at 15W for 3 min in mid follicular (MF) and mid luteal (ML) of menstrual cycle. Serum creatine kinase (CK), malondialdehyde (MDA), and superoxide dismutase (SOD) in the erythrocytes were measured before, immediately after and 24h after exercise. The VO2max, hart rate (HR), lactic acidosis (LA), and total exercise time were also recorded. Results: The levels of the CK and SOD were not significant changes before, immediately after and 24h after exercise during each phase of the menstrual cycle (p ＞ .05). However, the level of the MDA was significantly different between follicular phase and luteal phases of the menstrual cycle (12.01 ± 3.01 vs. 6.92 ± 3.05 nmol/ml, p ＜ .05), and it did not show a significant change after exercise during each phase of the menstrual cycle (p ＞ .05) via ANCOVA analysis. The VO2max, HR and LA were not changed but the exhaustion time between the mid-follicular phase and the mid-luteal phase (659.2 ± 101.7 vs. 690.7 ± 89.42 s, p ＜ .05). Conclusion: The findings of this study suggest that females may perform longer time before exhaustion, which may be due to a lower oxidative stress in mid luteal phase of menstrual cycle, but no different effects on oxidative stress and muscle damage in between were found.