The Influence Of Menstrual Phases On Perceived Athletic Performance, Motivation, And Competitiveness In Japanese Female Soccer Players

The dynamic fluctuations in female reproductive hormones may affect athletic performance as well as behavioral characteristics, such as motivation and competitiveness. However, limited research has explored the relationship. PURPOSE: This study aimed to investigate the association between menstrual phases and perceived performance, motivation, and competitiveness in Japanese female soccer players. METHODS: Sixteen Japanese semi-professional soccer players provided consent to participate in this study. The participants recorded their perceived athletic performance (rated from 1 to 10), motivation (rated from 1 to 7), and competitiveness (rated from 1 to 7) daily using a web application. Menstrual phases were determined by tracking menstrual cycles and using a home urinary hormone test kit measuring estrone-3-glucuronide (E3G), pregnanediol glucuronide (PdG), and luteinizing hormone (LH) daily after day 10 of the menstrual cycles. The menstrual phases were defined as follicular (FP), late follicular (LFP), ovulatory (OP), and luteal (LP) based on the hormonal testing. Friedman's test was used to compare the proportion of upper quintile scores for each variable among the phases, and individual Pearson residuals were also calculated to quantify the influence of the menstrual phase on the variables. RESULTS: Of the 32 menstrual cycles monitored (16 participants for two cycles), 26 were ovulatory and included in the analyses. The proportions of upper quintile scores for perceived performance, motivation, and competitiveness were all highest during the FP, but none of these differences were statistically significant (perceived performance, p = 0.31; motivation, p = 0.83; competitiveness, p = 0.79).The average individual Pearson residuals for FP, LFP, OP, and LP were 0.36, -0.25, -0.02, and 0.02 for performance; 0.08, -0.06, -0.01, and 0.05 for motivation; and 0.21, -0.03, -0.24, and 0.08 for competitiveness. CONCLUSION: This study did not find a significant association between menstrual phases and perceived performance, motivation, or competitiveness. Based on the small absolute values of Pearson residuals, the influence of menstrual phases on these variables appeared to be very limited in the studied cohort. Supported by: This study is granted by Japan Sports Medicine Foundation, 2024.