Recruiting
OBSERVATIONAL
NCT06985420
The Effect of the Menstrual Cycle on Immune Cell Activity and Recovery After Resistance Exercise
View on ClinicalTrials.gov
Updated Dec 15, 2025
Brief Summary
The goal of this observational study is to learn how the menstrual cycle affects immune cell activation, recruitment, and recovery responses after resistance exercise in healthy, resistance-trained women aged 18-40. The main questions it aims to answer are: Does the menstrual cycle influence neutrophil recruitment and adhesion after resistance exercise? Does the menstrual cycle affect markers of muscle damage and functional recovery? Researchers will compare three menstrual phases (early follicular, late follicular, and mid-luteal) to see if immune responses and recovery outcomes differ across these phases. Participants will: Complete resistance exercise protocols across three different menstrual cycle phases. Provide blood samples to assess immune cell activation and muscle damage markers. Track sleep, mood, and recovery with questionnaires and wear an accelerometer.
Interventions
Name:
Resistance exercise
Type:
OTHER
Description:
Resistance Exercise Protocols: Participants will perform exercises, including belt squats, hex bar deadlifts, and plyometric drop jumps. The load and intensity will be standardized based on each participant's 1-repetition maximum (1RM) to ensure uniformity across trials.
Name:
Menstrual Cycle Phases
Type:
OTHER
Description:
Menstrual Cycle Phases: The key exposure variable is the phase of the menstrual cycle, with participants being assessed during the early follicular, late follicular, and mid-luteal phases.
Primary Outcomes
Measure:
Neutrophil Recruitment and Adhesion Dynamics
TimeFrame:
From enrollment, through study completion, an average of 4 months.
Description:
Measure: Neutrophil cell index (impedance reflecting neutrophil migration) using Real-Time Cell Analysis (RTCA). Objective: To assess the differences in neutrophil recruitment and adhesion across menstrual cycle phases (early follicular, late follicular, and mid-luteal).
Time Frame: Assessed at 2 time points (baseline and 4 hours post exercise) on 3 experimental trial days (1 per menstrual cycle; up to 4 cycles per participant, over approximately 16 weeks).
Measure:
Systemic Concentrations of CXCL8
TimeFrame:
From enrollment, through study completion, an average of 4 months.
Description:
Measure: Plasma levels of CXCL8 (interleukin-8). Objective: To evaluate if menstrual cycle phases influence systemic chemokine levels in response to exercise.
Time Frame: Collected at 2 time points (baseline and 4 hours post exercise) on 3 experimental trial days (1 per menstrual cycle; up to 4 cycles per participant, over approximately 16 weeks).
Measure:
Muscle Function and Recovery- Active Range of Motion
TimeFrame:
From enrollment, through study completion, an average of 4 months.
Description:
Measure: Changes in active range of motion (AROM). Objective: To examine the impact of the menstrual cycle on functional recovery following resistance exercise.
Time Frame: Assessed at 5 time points (baseline, immediately post-exercise, 4 hours post, 24 hours post, and 48 hours post) on 3 experimental trial days (1 per menstrual cycle; up to 4 cycles per participant, over approximately 16 weeks).
Measure:
Muscle Function and Recovery- Pain Pressure Threshold
TimeFrame:
From enrollment, through study completion, an average of 4 months.
Description:
Measure: Changes in pain pressure threshold (PPT). Objective: To examine the impact of the menstrual cycle on functional recovery following resistance exercise.
Time Frame: Assessed at 5 time points (baseline, immediately post-exercise, 4 hours post, 24 hours post, and 48 hours post) on 3 experimental trial days (1 per menstrual cycle; up to 4 cycles per participant, over approximately 16 weeks).
Measure:
Muscle Function and Recovery - Countermovement Jump
TimeFrame:
From enrollment, through study completion, an average of 4 months.
Description:
Measure: Changes in countermovement jump (CMJ) height. Objective: To examine the impact of the menstrual cycle on functional recovery following resistance exercise.
Time Frame: Assessed at 5 time points (baseline, immediately post-exercise, 4 hours post, 24 hours post, and 48 hours post) on 3 experimental trial days (1 per menstrual cycle; up to 4 cycles per participant, over approximately 16 weeks).
Measure:
Muscle Function and Recovery - Maximal Voluntary Isometric Contraction
TimeFrame:
From enrollment, through study completion, an average of 4 months.
Description:
Measure: Changes in maximal voluntary isometric contraction (MVIC). Objective: To examine the impact of the menstrual cycle on functional recovery following resistance exercise.
Time Frame: Assessed at 5 time points (baseline, immediately post-exercise, 4 hours post, 24 hours post, and 48 hours post) on 3 experimental trial days (1 per menstrual cycle; up to 4 cycles per participant, over approximately 16 weeks).
Trial Information
NCT ID
NCT06985420
Status
Recruiting
Study Type
OBSERVATIONAL
Sponsor
University of Central Florida
Last Updated
December 15, 2025