Menstrual Cycle Phase and Oral Contraceptive Pill (OCP) Use on Muscle Protein Synthesis

Not Applicable

Completed

• Conditions: Menstrual Cycle; Resistance Exercise; Muscle Protein Synthesis; OCP
• Interventions: Other: Unilateral Resistance Exercise Leg; Other: Control Leg

• Registration Number: NCT05347667
• Lead Sponsor: McMaster University

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2022-04-21
• Study First Submitted QC: 2022-04-21
• Study First Posted: 2022-04-26
• Study Start: 2022-05-01
• Primary Completion: 2023-03-01
• Study Completion: 2024-04-30
• Status Verified: 2024-12
• Last Update Submitted: 2024-12-31
• Last Update Posted: 2025-01-01

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 24

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
• Irregular menstrual cycle as defined in the study protocol

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Pre-Ovulation Unilateral Resistance Exercise	Control Leg	One leg will undergo 2 sessions of unilateral resistance exercise during the follicular phase of the menstrual cycle (pre-ovulation).
Pre-Ovulation Unilateral Resistance Exercise	Unilateral Resistance Exercise Leg	One leg will undergo 2 sessions of unilateral resistance exercise during the follicular phase of the menstrual cycle (pre-ovulation).
Post-Ovulation Unilateral Resistance Exercise	Unilateral Resistance Exercise Leg	One leg will undergo 2 sessions of unilateral resistance exercise during the luteal phase of the menstrual cycle (post-ovulation).
Post-Ovulation Unilateral Resistance Exercise	Control Leg	One leg will undergo 2 sessions of unilateral resistance exercise during the luteal phase of the menstrual cycle (post-ovulation).

Primary Outcome Measures

Name	Time	Method
Change in Rates of Muscle Protein Synthesis	6 days	The investigators will use deuterated water and skeletal muscle biopsies to calculate the synthesis of skeletal muscle proteins.

Secondary Outcome Measures

Name	Time	Method
Whole-body proteolysis	6 days	The investigators will use 3-methylhistidine in urine to calculate the rate of whole-body myofibrillar protelysis

Trial Locations

Locations (1)

Exercise Metabolism Research Laboratory, McMaster Univeristy; 🇨🇦 Hamilton, Ontario, Canada