Description

This study investigates the neuromuscular effects of menstrual cycle-based resistance training by comparing three distinct training protocols among female athletes with natural menstrual cycles and a control group of athletes using oral contraceptives. Hormonal fluctuations across the menstrual phases can impact muscle performance, recovery, and neuromuscular function. This trial aims to align training intensity with menstrual cycle phases to enhance neuromuscular adaptations.

Study Design and Population

The trial is a controlled, randomized, open-label design involving 60 recreationally active female athletes aged 18 and above. Participants are allocated into four groups:

N-PF: Natural menstrual cycle with increased training intensity during the follicular phase.

N-PL: Natural menstrual cycle with increased training intensity during the luteal phase.

N-C: Natural menstrual cycle with continuous training intensity across all phases.

OCP-C: Oral contraceptive users with continuous training intensity. Each participant completes a 13-week resistance training program tailored to her group's specific phase-aligned training protocol, with two sessions per week. To assess the neuromuscular impact, we perform pre- and post-intervention evaluations across three key menstrual phases: early follicular, late follicular, and mid-luteal.

Neuromuscular Assessments Primary outcomes include maximal knee extensor strength, assessed through isokinetic testing, and secondary measures cover neuromuscular activation, rate of force development (RFD), muscle stiffness, and vertical jump performance (CMJ). These assessments are conducted during each of the three menstrual phases pre- and post-intervention to capture phase-specific neuromuscular adaptations. Blood sampling for hormonal verification (estradiol and progesterone levels) accompanies each phase-specific testing session.

Methodology and Rationale The training intensity and volume are adjusted based on the participant's menstrual phase to leverage hormonal benefits, with estrogen levels typically promoting muscular strength in the follicular phase and progesterone affecting endurance in the luteal phase. We hypothesize that phase-specific training may yield greater improvements in strength, muscle stiffness, and overall neuromuscular efficiency.

This study's findings are expected to provide novel insights into optimizing training loads for female athletes according to hormonal cycles, with implications for improving performance, reducing injury risk, and advancing individualized training and rehabilitation protocols.