Effect of exercise during the follicular and luteal phases on indices of oxidative stress in healthy women

Purpose: Eleven healthy nonsmoking women (24 +/- 1.1 yr) exercised for 30 m in at 75-80% (V) over dot O (2max) during the follicular (F) and luteal (L) phases of their menstrual cycle to determine whether menstrual phase influ enced indices df oxidative stress. Methods: Subjects completed the exercise in a randomized order. Subjects reported between 0800 and 0900 in a postab sorptive state, rested for 15-30 min, and had a venous blood sample obtaine d by Vacutainer before and after exercise. Results: Resting estradiol was 5 4.4 +/- 12.0 pg.mL(-1) for F phase and was significantly higher in L phase (147.2 +/- 25.5 pg.mL(-1)). Plasma malondialdehyde and thiobarbituric acid substances were no different before and after exercise independent of menst rual cycle phase. No diffuences in resting blood total glutathione (TGSH), oxidized glutathione (GSSG), and reduced glutathione (GSH) were evident com paring the F and L phases. After exercise, TOSH decreased (P = 0.03) but re ached significance only in the F phase = 8.1%(P = 0.04), L phase = 2.5% (P = 0.15). Exercise increased GSSG 10.5% in F (P = 0.15) and 27.8% in L phase s(P = 0.01). GSH decreased after exercise independent of menstrual phase (F = 17%, L = 16%, P = 0.01). Conclusion: These data suggest that 30 min of m oderate-intensity exercise in female subjects can result in mild oxidative stress as indicated by blood glutathione status and that menstrual cycle ph ase has minimal influences on these exercise responses.