Author(s): LIN, C., Institution: NATIONAL CHENG KUNG UNIVERSITY, Country: TAIWAN, Abstract-ID: 1536

INTRODUCTION:
The influence of the menstrual cycle on athletic performance remains a complex area of study due to significant inter-individual hormonal variability. This study investigated the relationship between fluctuations in sex hormones and various physical and psychological parameters across different menstrual phases.
METHODS:
Eight female participants (N=8, age=26±11.06 yrs; BMI=22±0.76) were monitored across the early follicular, late follicular, ovulation, and luteal phases for consecutive 3 months. Physiological measures included progesterone, luteinizing hormone (LH), estrogen, and follicle-stimulating hormone (FSH). Physical performance was assessed via Y-Balance (stability), countermovement jump (CMJ) (explosive power), and sit-and-reach (flexibility). Muscle stiffness was measured at the lumbar spine, gluteus maximus, biceps femoris, gastrocnemius, and rectus femoris. Psychological well-being and fatigue were evaluated using questionnaires including the Fatigue Assessment Scale, Fatigue Severity Scale, Premenstrual Syndrome Scale, Sport Motivation Scale, and WHOQOL-BREF.
RESULTS:
Multivariate analysis of variance (MANOVA) confirmed significant hormonal variation across all cycle phases (p < .001). While no significant main effect of the cycle phase was found for muscle stiffness, balance, or jumping performance, strong correlations emerged between specific hormones and performance metrics. In early follicular, LH and progesterone significantly correlated with biceps femoris stiffness (p < .05) and gastrocnemius stiffness (p < .01). In late follicular, LH showed a significant correlation with CMJ performance (p < .05) and stability (p < .05) while in luteal phase, LH was strongly associated with lumbar spine stiffness (p < .01), stability (p < .01), and CMJ (p < .05). In the luteal phase, progesterone and FSH were significantly correlated with fatigue severity (p < .05) and premenstrual syndrome (PMS) scores (p < .01).
CONCLUSION:
Although the phase of the menstrual cycle alone may not result in categorical performance changes, individual hormonal concentrations, particularly LH, are significantly linked to neuromuscular stability and explosive power. Furthermore, hormonal peaks in the luteal phase are closely tied to increased fatigue and reduced quality of life. These findings suggest that individualized monitoring of hormonal profiles, rather than phase-tracking alone, is essential for optimizing female athletic training.