The Effect of the Menstrual Cycle on Immune Cell Activity and Recovery After Resistance Exercise
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexFemale
Age18-40
SponsorUniversity of Central Florida
About this trial
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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Women between the ages of 18 and 40.
Must weigh at least 110 pounds.
Healthy as determined by medical history, physical activity readiness, and menstrual cycle questionnaires.
Actively resistance training for at least 6 months (minimum of 3 resistance training sessions per week, with at least one lower body session).
Disqualifiers
Do not give consent to participate.
Have been determined unfit to participate based on medical or activity history (using health questionnaires).
Currently take prescription or over-the-counter medication that could affect the study results.
Have a chronic illness requiring medical care.
Trial population
Participants will be recruited from the local community and university setting, specifically from the University of Central Florida and surrounding areas. The population will consist of healthy, resistance-trained women aged 18 to 40 who are physically active and meet the criteria for regular menstrual cycles. Participants will likely be university students, staff, or individuals involved in local fitness and sports communities, with a focus on those who are familiar with structured resistance training. Recruitment will aim to reflect a diverse range of backgrounds while ensuring participants meet the health and exercise requirements of the study.
Trial design
Design model
Other
Time perspective
Other
Treatments tested in this trial
Resistance exercise
Other interventionResistance 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.
Menstrual Cycle Phases
Other interventionMenstrual 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.
Treatment groups
No treatment groups listed
Trial outcomes
Primary outcomes
1
Neutrophil Recruitment and Adhesion Dynamics
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).
Time frame
From enrollment, through study completion, an average of 4 months.2
Systemic Concentrations of CXCL8
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).
Time frame
From enrollment, through study completion, an average of 4 months.3
Muscle Function and Recovery- Active Range of Motion
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).
Time frame
From enrollment, through study completion, an average of 4 months.4
Muscle Function and Recovery- Pain Pressure Threshold
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).
Time frame
From enrollment, through study completion, an average of 4 months.Secondary outcomes
1
Systemic Concentrations of Myoglobin
Measure: Plasma levels of myoglobin (MYB). Objective: To determine how menstrual cycle phases affect muscle damage/inflammation markers after resistance exercise. Time Frame: Collected at 5 time points (baseline, immediately post-exercise, 4 hours post, 24 hours post, and 48 hours post) on 3 experimental trial days per participant (approximately 16 weeks total).
Time frame
From enrollment, through study completion, an average of 4 months.2
Systemic Concentrations of Creatine kinase
Measure: Plasma levels of creatine kinase (CK). Objective: To determine how menstrual cycle phases affect muscle damage/inflammation markers after resistance exercise. Time Frame: Collected at 5 time points (baseline, immediately post-exercise, 4 hours post, 24 hours post, and 48 hours post) on 3 experimental trial days per participant (approximately 16 weeks total).
Time frame
From enrollment, through study completion, an average of 4 months.3
Systemic Concentrations of C-Reactive Protein
Measure: Plasma levels of C-reactive protein (CRP). Objective: To determine how menstrual cycle phases affect muscle damage/inflammation markers after resistance exercise. Time Frame: Collected at 5 time points (baseline, immediately post-exercise, 4 hours post, 24 hours post, and 48 hours post) on 3 experimental trial days per participant (approximately 16 weeks total).
Time frame
From enrollment, through study completion, an average of 4 months.4
Subjective Measures of Perceived Recovery
Measure: Perceived Recovery Status Scale score. Objective: To assess perceived recovery and performance across menstrual cycle phases. Time Frame: Assessed at 5 time points (baseline, immediately post, 4 hours, 24 hours, and 48 hours post-exercise) on up to 3 experimental trial days (approximately 16 weeks total).
Time frame
From enrollment, through study completion, an average of 4 months.Other outcomes
1
Cardiovascular Responses to Exercise
Measure: Heart rate (beats per minute) recorded during exercise using a Polar H10 heart rate monitor. Objective: To measure the cardiovascular demand of resistance exercise and determine if it varies by menstrual phase. Time Frame: Continuously monitored during each exercise session on 3 experimental trial days (approximately 16 weeks total).
Time frame
From enrollment, through study completion, an average of 4 months.2
Exercise Enjoyment
Measure: Physical Activity Enjoyment Scale (PACES; score range 18-126, higher scores = greater enjoyment). Objective: To evaluate whether menstrual cycle phases influence exercise enjoyment. Time Frame: Assessed immediately post-exercise on 3 experimental trial days (approximately 16 weeks total).
Time frame
From enrollment, through study completion, an average of 4 months.3
Rating of Perceived Exertion (RPE)
Measure: Rating of Perceived Exertion (RPE; scale 6-20, higher = greater effort). Time Frame: Assessed after each exercise set and immediately post-exercise on 3 experimental trial days.
Time frame
From enrollment, through study completion, an average of 4 months.4
Repetitions in Reserve (RIR)
Measure: Repetitions in Reserve (RIR; reps estimated to be left in reserve). Time Frame: Assessed after each exercise set on 3 experimental trial days.
Time frame
From enrollment, through study completion, an average of 4 months.Sponsors and contacts
Click on the lead sponsor to view all of their trials.
Source ClinicalTrials.gov