Effects of menstrual cycle phase on straight punch performance and explosive power in elite female boxers

Purpose To compare straight punch performance and explosive power across the early follicular, ovulatory, and mid-luteal phases of the menstrual cycle in elite female boxers, and to examine the relationship between hormone changes and performance changes. Methods Twenty-four national first-class female boxers participated in a prospective longitudinal repeated-measures design. Cycle phases were verified using basal body temperature, urinary luteinizing hormone testing, and salivary hormones. Lead and rear straight punch peak force and peak velocity were measured, along with countermovement jump relative peak power, rotational medicine ball throw distance, and bench press throw relative peak power. Salivary estradiol, progesterone, and free testosterone were measured using LC-MS/MS. Repeated-measures ANOVA was used to compare phases, with Bonferroni-adjusted post hoc comparisons and partial η² reported. Individual response proportions and correlations between hormone changes and performance changes were calculated. Results All punch performance and explosive power variables peaked during the ovulatory phase, with large effect sizes (partial η²=0.175–0.451). No significant differences were observed between the early follicular and mid-luteal phases. Salivary estradiol, progesterone, and free testosterone exhibited expected cyclic fluctuations, confirming valid phase classification. Approximately 70.8%–91.7% of athletes improved during the ovulatory phase. However, no significant correlations were identified between hormone changes and performance changes, with Pearson correlation coefficients (r) ranging from −0.180 to 0.395 (all P>0.05). Conclusion Menstrual cycle phase significantly influences straight punch performance and explosive power in elite female boxers, with the ovulatory phase representing a peak performance window. However, the decoupling between hormone changes and performance changes, along with substantial individual variability, suggests that uniform phase-based training prescriptions remain premature; individualised monitoring should guide future training arrangements.