Influence of Second-Generation Oral Contraceptives on Muscle Recovery after Repeated Resistance Exercise in Trained Females

Purpose Oral contraceptives (OCs) are commonly used by female athletes, but their effects on skeletal muscle are still poorly understood. We investigated if physically trained females using second-generation OCs differed from nonusers of OCs in the recovery of muscle function and muscle damage markers after repeated resistance exercise sessions. Methods We recruited 20 trained second-generation OC users and 20 trained nonusers to perform three strenuous resistance exercise sessions. Before, and 3, 24, and 48 h after exercise, blood samples were collected, and participants were evaluated for muscle soreness, maximal isometric and isokinetic muscle strength, vertical jump height, Wingate power performance, leg press strength, and intermittent recovery capacity (yo-yo test). All participants were provided with an energy-macronutrient-balanced diet during the experimental period. Results After resistance exercise, maximal isometric and isokinetic muscle strength, rate of force development, vertical jump height, and Wingate peak and average power were reduced, whereas markers of muscle damage were increased in both groups (P < 0.05). OC users experienced a greater reduction in isokinetic strength 3, 24, and 48 h after exercise compared with nonusers of OCs (interaction: P < 0.05). No other interactions were observed. Conclusions We demonstrate that measures of muscle strength recovery after three strenuous resistance exercise sessions are comparable between trained females using second-generation OCs and nonusers of OCs. However, group differences were observed for isolated dynamic (isokinetic) muscle strength, suggesting a marginal benefit of not using OCs when accelerated recovery is needed.