Menstrual Cycle Phase Muscle Protein Synthesis

Study Overview
=================
Brief Summary
-----------------
Skeletal muscle size and function is regulated by various factors, including hormones. While we understand the role of male sex hormones (testosterone), we aren't sure how female sex hormones (estrogen and progesterone) influence muscle mass and strength. Female physiology is unique in that hormones fluctuate throughout the menstrual cycle. In the first phase (follicular phase) following menstruation, estrogen levels are high while progesterone levels are low. In the second phase (luteal phase), progesterone levels are high. Females are often excluded from studies because researchers are concerned that the menstrual cycle might affect the results. The purpose of this study is to investigate the response to resistance exercise in each phase of the menstrual cycle.

Official Title
-----------------
Influence of Menstrual Cycle Phase on the Muscle Protein Synthetic Response to Exercise in Young, Healthy, Naturally Cycling Women

Conditions
-----------------
Menstrual Cycle, Resistance Exercise, Muscle Protein Synthesis

Intervention / Treatment
-----------------
* Other: Unilateral Resistance Exercise Leg
* Other: Control Leg


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Healthy females, between the ages of 18 and 30 y with a regular menstrual cycle Body Mass Index between 18.5 and 30.0 kg/m2 Able and willing to provide informed consent Exclusion Criteria: A history of neuromuscular disorders or muscle/bone wasting diseases Any acute or chronic illness, cardiac, pulmonary, liver, or kidney abnormalities, uncontrolled hypertension, insulin-dependent or insulin-independent diabetes, or the presence of any other metabolic disease - all of which will be determined via a medical history screening questionnaire The use of any medications known to affect protein metabolism (glucocorticoids, non-steroidal anti-inflammatory medication, or prescription strength acne medication, etc.) A (family) history of thrombosis The use of anticoagulant medications Consumption of tobacco-containing products Excessive alcohol consumption (>21 units/wk) History of bleeding diathesis, platelet or coagulation disorders Currently pregnant The use of hormonal contraceptives Irregular menstrual cycle

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: In a randomized fashion, participants will have one leg undergo unilateral resistance exercise training to assess the muscle protein synthetic response in each menstrual cycle phase.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pre-Ovulation Unilateral Resistance Exercise<br>One leg will undergo 2 sessions of unilateral resistance exercise during the follicular phase of the menstrual cycle (pre-ovulation). | Other: Unilateral Resistance Exercise Leg<br>* One leg will perform unilateral resistance exercise<br>Other: Control Leg<br>* One leg will serve as a non-exercise control<br>|
| Experimental: Post-Ovulation Unilateral Resistance Exercise<br>One leg will undergo 2 sessions of unilateral resistance exercise during the luteal phase of the menstrual cycle (post-ovulation). | Other: Unilateral Resistance Exercise Leg<br>* One leg will perform unilateral resistance exercise<br>Other: Control Leg<br>* One leg will serve as a non-exercise control<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Rates of Muscle Protein Synthesis | The investigators will use deuterated water and skeletal muscle biopsies to calculate the synthesis of skeletal muscle proteins. | 6 days |