Effects of Menstrual Cycle Phases on Neuromuscular Performance in Elite Adolescent Female Team Sport Athletes

ABSTRACT: Fort-Vanmeerhaeghe, A, Milà-Villarroel, R, Pujol-Marzo, M, Casadevall-Sayeras, P, Nieto-Guisado, A, Nevot-Casas, O, and Peña, J. Effects of menstrual cycle phases on neuromuscular performance in elite adolescent female team sport athletes. J Strength Cond Res XX(X): 000-000, 2026-Hormonal fluctuations across the MC may influence neuromuscular performance in female athletes; however, evidence in adolescent populations remains limited. This study aimed to examine the effects of 3 MC phases-early follicular (EFP), late follicular, and late luteal-on vertical jump performance and upper-body strength endurance in elite adolescent female team sport athletes. Thirty-two eumenorrheic basketball and volleyball athletes (mean age = 16.1 ± 1.3 years) were assessed across 3 consecutive natural MCs. Neuromuscular performance was evaluated in each phase using countermovement jump (CMJ; mean and maximum height) and bench press repetitions at 80% of 1-repetition maximum. Linear mixed-effects models were used to account for repeated observations nested within MCs and subjects. The menstrual phase was included as a fixed effect, with random intercepts for subjects and cycles nested within subjects. Significant main effects of phase were observed for CMJ mean height (p < 0.001), CMJ maximal height (p < 0.001), and bench press repetitions at 80% 1-repetition maximum (p = 0.001), with lower performance during the EFP compared with later phases. These results suggest that the EFP, concurrent with menstruation, is associated with reduced neuromuscular performance in adolescent athletes. Practical applications include the importance of MC tracking and individualized training adjustments to optimize performance and potentially reduce injury risk during vulnerable phases.