Resumen de The Effect of the Oral Contraceptive Cycle Phase on Exercise-Induced Muscle Damage After Eccentric Exercise in Resistance-Trained Women
Nuria Romero Parra, Beatriz Rael, Víctor M. Alfaro Magallanes, Xanne A.K. Janse de Jonge, Rocío Cupeiro Coto, Ana Belén Peinado Lozano
To evaluate the influence of the active pill phase versus withdrawal phase of a monophasic oral contraceptive (OC) cycle on exercise-induced muscle damage and inflammation after eccentric resistance exercise. Eighteen resistance-trained female OC users (age: 25.6 +/- 4.2 years, height: 162.4 +/- 5.0 cm, and body mass: 58.1 +/- 5.7 kg) performed an eccentric squat-based exercise during the active pill phase and withdrawal phase of their OC cycle. Muscle soreness, counter movement jump (CMJ), and blood markers of muscle damage and inflammation were evaluated before and postexercise (0, 2, 24, and 48 hours). Creatine kinase (CK) values were higher in the withdrawal (181.8 +/- 89.8 U[middle dot]L-1) than in the active pill phase (144.0 +/- 39.7 U[middle dot]L-1) (p < 0.001). The highest CK concentrations and muscle soreness values were observed 24 hours postexercise (217.9 +/- 117.5 U[middle dot]L-1 and 44.7 +/- 19.7, respectively) compared with baseline (115.3 +/- 37.4 U[middle dot]L-1 and 4.4 +/- 9.2, respectively; p < 0.001). In addition, a decrease in CMJ immediately postexercise (20.23 +/- 4.6 cm) was observed in comparison with baseline (24.2 +/- 6.1 cm), which was not yet recovered 24 hours postexercise (21.9 +/- 5.9 cm; p < 0.001). No other phase or time effects were observed. An eccentric squat-based exercise session elicits muscle damage but no inflammation response in resistance-trained women. Furthermore, the highest CK concentrations observed in the withdrawal phase suggest that this phase might be more vulnerable to muscle damage and, therefore, less adequate to administer high training loads. However, the lack of differences in other muscle damage variables between OC phases does not warrant any guidance on the active pill versus withdrawal phase.
