CASE, D., J. T. BAER, and M. T. R. SUBBIAH. The effect of prolonged exercise on lipid peroxidation in eumenorrheic female runners. Med. Sci. Sports Exerc., Vol. 31, No. 10, pp. 1390–1393, 1999.
Purpose: Recently a protective role has been demonstrated for 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 dienes) 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 not appear to increase potential for lipid peroxidation in trained eumenorrheic runners during a low estrogen phase of the menstrual cycle.