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

Launched by UNIVERSITY OF CENTRAL FLORIDA · May 14, 2025

Keywords

ClinConnect Summary

This clinical trial is studying how the menstrual cycle affects the body’s immune response and recovery after resistance exercise in healthy women. Researchers want to find out if different phases of the menstrual cycle—specifically the early follicular, late follicular, and mid-luteal phases—change how immune cells react and how muscle damage and recovery occur after working out. The goal is to improve our understanding of how women might recover from exercise at different times in their menstrual cycle.

To participate, women must be between 18 and 40 years old, weigh at least 110 pounds, and have been actively resistance training for at least six months. Participants will engage in resistance exercise during three different menstrual phases, provide blood samples to measure immune responses and muscle damage, and share information about their sleep, mood, and recovery through questionnaires. It’s important to note that women who are pregnant, using hormonal birth control, or have certain medical conditions may not be eligible for the study. This research could help tailor exercise and recovery strategies for women based on their menstrual cycle.

Gender

FEMALE

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.