The effect of prolonged exercise on lipid peroxidation in eumenorrheic female runners

Purpose: Recently a protective role has been demonstrated fur estrogens as free radical scavengers. In this study, lipid peroxidation was evaluated in eumenorrheic runners before and after participation in a half-marathon. Methods: Seven female runners who participated in regular training (average 25 miles.wk(-1)) and reported regular menses (12/yr) served as subjects. Subjects were all in a low estrogen phase of their menstrual cycle as confirmed by menstrual record and plasma estradiol level (42.71 +/- 21.65 pg.mL(-1)). Low density lipoprotein oxidation (formation of conjugated dimes) was determined 2 h prerace and 5 min after subject's completion of the race. Results: Results showed a significant increase in lag phase time of conjugated dienes after prolonged exercise (28.43 +/- 4.89 min vs postrace 35.21 +/- 4.32 min, P < 0.05). No correlation between mean levels of estradiol and mean lipid peroxidation levels at rest. 5 min after exercise, or difference (prepost) was observed. Conclusion: Prolonged endurance exercise does nor appear to increase potential for lipid peroxidation in trained eumenorrheic runners during a low estrogen phase of the menstrual cycle.