NCT05934708 · University of Southern California
Examining the Role of Female Endogenous Sex Hormones in Eccentric Exercise
What this study is about
The fluctuating concentrations of female sex hormones, namely estrogen and progesterone may have an effect on the ability of the tissue to withstand challenging exercise conditions, such as eccentric exercise. These sex hormones have also been purported to influence the perceived difficulty of exercise.
View original scientific description
The fluctuating concentrations of female sex hormones, namely estrogen and progesterone may have an effect on the ability of the tissue to withstand challenging exercise conditions, such as eccentric exercise. These sex hormones have also been purported to influence the perceived difficulty of exercise. This study aims to uncover how the different estrogen and progesterone concentrations present throughout the menstrual cycle effect perceived readiness to perform, perceptions of difficulty, and different recovery metrics.
Interventions
BEHAVIORAL
Eccentric leg extension
Participants will complete a 10 x 10 eccentric leg extension on a Cybex Norm dynamometer. Upon arrival, participants will be asked their perceived readiness to perform on a 11 point numeric rating scale. Before the running protocol a baseline blood sample will be collected, as well as passive and active delayed onset muscle soreness (DOMS), a countermovement jump. Half way through each set (i.e., after the 5th repetition) participants will be asked to rank their level of difficulty on a 11 point OMNI Res scale. This will occur during each set. Participants will have follow up blood draws, measures of muscle function (i.e, jump height) and soreness measured immediately after and 24 and 48 hours post-exercise.
Primary outcome measures
Preparedness to perform
Time frame: Pre exercise
Perceived readiness will be measured on an 11 point numeric rating scale (NRS) with 0 being not ready at all, and 10 being most prepared
Rating of difficulty
Time frame: 30 minutes
Perceived difficulty will be measured on a 11 point numeric rating scale called the OMNI res throughout the duration of exercise.
Inflammatory markers
Time frame: Change over time (pre/post, 24 hour, 48 hour)
Inflammatory markers (IL-6, IL-8, TNF-alpha, and IL-10) will be measured in blood serum to understand how the concentration of estrogen changes the inflammatory response to damaging exercise.
Counter movement jump height
Time frame: Change over time (pre/post, 24 hour, 48 hour)
A countermovement jump (CMJ) will be performed on VALD ForceDecks to determine muscle function overtime.
Passive Delayed Onset Muscle Soreness (DOMS)
Time frame: Change over time (pre/post, 24 hour, 48 hour)
DOMS will be assessed as participants are stationary to assess their perception of muscle damage over time.
Active Delayed Onset Muscle Soreness (DOMS)
Time frame: Change over time (pre/post, 24 hour, 48 hour)
DOMS will be assessed as participants complete a wall sit to assess their perception of muscle soreness over time.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 18-35 years of age
- BMI of 18.5-29.9 as a BMI below or above these cut points results in highly varied menstrual cycle lengths \[15\]
- Not taking contraception or other types of medication that could influence reproductive status
- Regular menstruation
- Non-pregnant
- Medically free from chronic diseases
- Novel to downhill running
- Weight greater than or equal to 110 lbs
- Not taking exogenous hormones
- Not suffering from known gynecological disease (i.e., PCOS, endometriosis, etc.) that may influence menstrual cycle regularity
Exclusion criteria
- Amenorrhea or oligomenorrhea
- Perimenopausal or menopausal
- Recreational or professional trail or downhill runner
- On a form of contraception
- Cardiac disability
- Arterial disease
- Uncontrolled hemorrhage
- Blood clots
- Pregnant or trying to become pregnant
- Cancerous lesions
- Sensory or mental impairment
- Unstable fractures
- Weight less than 110 lbs
- Suffering from gynecological disease (i.e., PCOS, endometriosis, etc.) that may influence menstrual cycle regularity
- Taking exogenous hormones
Where
- Los Angeles, California
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 25, 2026 · Source of record for eligibility and locations