Oral contraceptive use and exercise-induced muscle damage and recovery.

Endogenous estrogen appears to attenuate muscle damage in animals; however, similar evidence in humans is not as strong. This investigation tested the hypothesis that women taking oral contraceptives, thereby having higher exogenous estrogen levels, would be more susceptible to damage or have an attenuated recovery from exercise-induced muscle damage. Muscle damage in women taking combined estrogen and progesterone oral contraceptives (OC) were compared to noncontraceptive users (NOC) after 50 eccentric muscle contractions of the elbow flexors. Measures of maximal isometric strength (MIS), range of motion (ROM), arm circumference (CIR), soreness (SOR), and serum creatine kinase (CK) activity were taken pre- and for 5 days post-exercise. All measures following exercises were similar between groups with the exception of MIS. Force recovery began 2 days post-exercise in the NOC group, while in the OC group strength did not start to return to normal until 4 days post-exercise (p < 0.05). Women taking oral contraceptives had a delayed strength recovery after eccentric exercise.