Monitoramento longitudinal do ciclo menstrual e sua influência no desempenho e nas respostas psicofisiológicas de nadadoras

Abstract

Introduction: Athletic performance is a multifactorial phenomenon resulting from the interaction between physiological, perceptual, and emotional factors. Despite the increasing participation of women in competitive sports, female athletes remain underrepresented in the literature, particularly in longitudinal studies examining the influence of the menstrual cycle (MC) on performance and psychophysiological responses in endurance-based sports such as swimming. Objective: To longitudinally investigate the influence of menstrual cycle phases on athletic performance and psychophysiological variables in young female swimmers during a competitive preparation period, as well as to conduct a sex-specific comparative analysis with male swimmers. Methods: This observational, analytical, and longitudinal study was conducted over 16 weeks and included 21 competitive swimmers (10 females and 11 males), competing at regional to international levels. Performance was assessed through swimming velocity recorded during the main set of training sessions and categorized into intensity zones (ZI–ZV). Psychophysiological variables included rating of perceived exertion (RPE), perceived recovery status (PRS), sleep quality (PSQI), affective states (valence and activation), and preference and tolerance for exercise intensity (PRETIE-Q). The menstrual cycle was initially characterized using hormonal assessments (estradiol and progesterone) and subsequently monitored through phase estimation, ovulation testing, and tracking of premenstrual symptoms (PSST). Statistical analyses included mixed-effects models, nonparametric tests for repeated measures, Spearman correlations, and effect size calculations, with a significance level set at 5%. Results: In female swimmers, swimming velocity varied significantly across MC phases in intensity zones III (H(4)=95.17; p<0.001; ε²=0.05) and IV (H(4)=65.21; p<0.001; ε²=0.03), with a consistent reduction in performance during phase 4 compared with other phases. Concurrently, RPE was significantly higher in phase 4 in zones III (H(4)=199.4; p<0.001; ε²=0.03) and IV (H(4)=279.0; p<0.001; ε²=0.04), while PRS was significantly lower in the same zones (p≤0.002). Sleep quality worsened significantly during phase 4 (H=12.97; p<0.001; η²=0.06), characterized by reduced sleep duration and efficiency. Affective states shifted toward more negative quadrants during phase 4, particularly at higher intensities. In contrast, male swimmers did not exhibit a consistent pattern of swimming velocity variation across equivalent phases, despite occasional fluctuations in psychophysiological variables. Conclusion: Athletic performance in female swimmers is modulated by psychophysiological changes associated with menstrual cycle phases. Phase 4 was consistently associated with poorer sleep quality, higher perceived exertion, lower perceived recovery, and more negative affective states, resulting in reduced swimming velocity during training sessions characterized by moderate-to-high intensities (zones III and IV), where menstrual cycle effects were most evident. Sex-specific analysis indicated lower psychophysiological and performance variability in male swimmers throughout the training period.