How does menstrual cycle affect female football players’ performance during small-sided games?

This study aimed to compare the perceptual state, physical, technical, and tactical performances of youth female football players in small-sided and conditioned games (SSCG) across different menstrual cycle phases. A total of twenty-seven under-19 players were monitored over 3 months using daily questionnaires and basal temperature to track menstrual phases. Players with synchronized cycles (n = 6, age: 16.5 ± 0.76 years) participated in 3-a-side with goalkeepers SSCGs, under follicular (FOL) and luteal (LUT) conditions. No significant effects were found in perceptual scales, though motivation scores were higher in the FOL phase (effect Cohen d = 0.80 [0.04; 1.57]). Technical performance was higher during FOL for shooting decision (p < .01, Cohen d = 0.71 [0.26; 1.16]) and target orientation (p < .05, Cohen d = 0.50 [0.10; 0.90]) compared to LUT. Positional analysis revealed greater distance to the nearest teammate (p < .01, Cohen d = 0.49 [0.14; 0.84]) but lower variability (CV, p < .001, Cohen d = -0.82 [-1.17; −0.47]) in FOL. No physical performance differences were detected. These findings suggest that while physical and perceptual performance remains stable across menstrual phases, subtle variations in technical and positional behavior may indicate that menstrual cycle phases could be considered when designing training. This pilot study highlights preliminary trends, particularly in relational positional variables, which merit further exploration in future research to better understand their implications.