Clinical trial NCT06985420: The Effect of the Menstrual Cycle on Immune Cell Activity and Recovery After Resistance Exercise
Official title: The Impact of the Menstrual Cycle on Innate Immune Cell Activation, Recruitment, and Adhesion Dynamics During Recovery From Damaging Resistance Exercise: Role of Neutrophils and Systemic Chemokines.
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Healthy Women
Menstruation
Resistance Exercise
Lead sponsor: University of Central Florida
Sponsor class: OTHER
First posted: 2025-05-22
Enrollment: 40
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: no
Observational model: OTHER
Time perspective: OTHER
Sampling method: NON_PROBABILITY_SAMPLE
Study 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.

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.


Eligibility criteria: Inclusion Criteria:

* 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).
* Pre-menopausal and have a regular menstrual cycle (eumenorrheic), with a clear start of menses (early follicular phase).
* Not currently pregnant or planning to become pregnant during the study.
* Have not used hormonal birth control or intrauterine devices in the past 3 months (or three full menstrual cycles).
* Able to recall approximate start dates of their last 6 menstrual cycles.
* Willing to follow study instructions, including avoiding exercise, alcohol, and caffeine before testing visits.
* Free from previous or current lower body injuries that could limit performance.
* Not regularly taking any medications that could interfere with the study.
* Determined to have a high likelihood of successful blood draws by a certified phlebotomist.

Exclusion Criteria:

* 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.
* Not currently resistance-trained (don't meet the exercise requirement).
* Pregnant or planning to become pregnant during the study.
* Do not have regular periods or have been diagnosed as amenorrhoeic (absence of menstruation).
* Currently taking any performance-enhancing drugs.
* Currently using hormonal birth control or intrauterine devices (IUDs), or have used them in the past three months (or three full menstrual cycles).
* Determined unlikely to have a successful blood draw by a trained phlebotomist.
* Weigh less than 110 pounds.

Primary outcomes:
measure: Neutrophil Recruitment and Adhesion Dynamics
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Systemic Concentrations of CXCL8
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Muscle Function and Recovery- Active Range of Motion
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Muscle Function and Recovery- Pain Pressure Threshold
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Muscle Function and Recovery - Countermovement Jump
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Muscle Function and Recovery - Maximal Voluntary Isometric Contraction
timeFrame: From enrollment, through study completion, an average of 4 months.
Secondary outcomes:
measure: Systemic Concentrations of Myoglobin
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Systemic Concentrations of Creatine kinase
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Systemic Concentrations of C-Reactive Protein
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Subjective Measures of Perceived Recovery
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Subjective Measures of Perceived Recovery
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Subjective Measures of Fatigue
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Subjective Measures of Soreness
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Subjective Sleep Quality
timeFrame: Time Frame: From enrollment, through study completion, an average of 4 months.
measure: Subjective Sleep Quality
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Objective Sleep Quality
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Mood
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Menstrual Distress
timeFrame: From enrollment, through study completion, an average of 4 months.
Other outcomes:
measure: Cardiovascular Responses to Exercise
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Exercise Enjoyment
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Rating of Perceived Exertion (RPE)
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Repetitions in Reserve (RIR)
timeFrame: From enrollment, through study completion, an average of 4 months.
measure: Visual Analog Scale - Exercise Difficulty
timeFrame: From enrollment, through study completion, an average of 4 months.
Locations:
city: Orlando
country: United States
facility: University of Central Florida
state: Florida
Study officials:
References: