2026 Volume 11 Issue 2 Pages 121-129
Participants were followed over two consecutive menstrual cycles. During the follow-up period, they measured levels of estrone-3-glucuronide, pregnanediol glucuronide, and luteinizing hormone using at-home hormone testing kits from day 10 of the menstrual cycle until ovulation was confirmed, to identify the timing of ovulation and menstrual phases. Participants also recorded their subjective levels of motivation (1-7), competitiveness (1-7), and sports performance (1-10) daily via a web application as indicators of behavioral characteristics. Data completeness was used as a measure of study feasibility. The associations between menstrual phases and behavioral characteristics were examined using Friedman’s test with Kendall’s W. Additionally, correlations between hormone levels and behavioral characteristics were evaluated using Spearman’s correlation coefficient. Impeccable data completeness (98.2%) and no participant withdrawals demonstrated the feasibility of daily data entry and hormone monitoring. However, Friedman’s test revealed no significant differences in motivation (p＝0.82), competitiveness (p＝0.24), or subjective performance (p＝0.55) across menstrual phases, with very small effect sizes (Kendall’s W: motivation＝0.02, competitiveness＝0.09, perceived performance＝0.05). Furthermore, no notable correlations were found between hormone levels and behavioral characteristics.In conclusion, this study demonstrated that daily data collection using at-home hormone testing kits is feasible with high adherence. However, no statistically significant associations were observed between menstrual phases and subjective behavioral characteristics, and the effect sizes were minimal. It is likely that the validity of the measured items and their corresponding scales was limited. Future studies should consider incorporating objective measures of actual behavior in female athletes.
