The Effect of the Menstrual Cycle on Immune Cell Activity and Recovery After Resistance Exercise

NCT06985420 | Recruiting

• 1 other identifier: STUDY00006956
• Study Type: observational
• Target: 40
• Locations: 1 country
• Sites: 1

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.

Conditions

Healthy Women; Menstruation; Resistance Exercise

Outcome Measures

Primary Outcomes (6)

• 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).

  From enrollment, through study completion, an average of 4 months.

• 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).

  From enrollment, through study completion, an average of 4 months.

• 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).

  From enrollment, through study completion, an average of 4 months.

• 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).

  From enrollment, through study completion, an average of 4 months.

• Muscle Function and Recovery - Countermovement Jump

  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).

  From enrollment, through study completion, an average of 4 months.

• Muscle Function and Recovery - Maximal Voluntary Isometric Contraction

  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).

  From enrollment, through study completion, an average of 4 months.

Secondary Outcomes (12)

• Systemic Concentrations of Myoglobin

  From enrollment, through study completion, an average of 4 months.

• Systemic Concentrations of Creatine kinase

  From enrollment, through study completion, an average of 4 months.

• Systemic Concentrations of C-Reactive Protein

  From enrollment, through study completion, an average of 4 months.

• Subjective Measures of Perceived Recovery

  From enrollment, through study completion, an average of 4 months.

• Subjective Measures of Perceived Recovery

  From enrollment, through study completion, an average of 4 months.

Other Outcomes (5)

• Cardiovascular Responses to Exercise

  From enrollment, through study completion, an average of 4 months.

• Exercise Enjoyment

  From enrollment, through study completion, an average of 4 months.

• Rating of Perceived Exertion (RPE)

  From enrollment, through study completion, an average of 4 months.

Interventions

Resistance exercise OTHER

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.

Menstrual Cycle Phases OTHER

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.

Eligibility Criteria

• Age: 18 Years - 40 Years
• Healthy Volunteers: No
• Age Groups: Adult (18-64)
• 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.

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• University of Central Florida: lead

Study Sites (1)

University of Central Florida

Orlando, Florida, 32816, United States

RECRUITING

Related Links

• Recruitment Website

MeSH Terms

Interventions

Resistance Training

Intervention Hierarchy (Ancestors)

Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Patient Care; Therapeutics; Physical Therapy Modalities; Physical Conditioning, Human; Exercise; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Central Study Contacts

Jessica M Moon

CONTACT

407-823-0623; jessica.moon@ucf.edu

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: OTHER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Graduate Research Assistant, PhD Candidate, Principal Investigator

Study Record Dates

• First Submitted: September 16, 2024
• First Posted: May 22, 2025
• Study Start: August 16, 2024
• Primary Completion: May 1, 2025
• Study Completion: May 1, 2025
• Last Updated: May 22, 2025

Record last verified: 2025-05

Locations

US (1)