Menstrual Cycle, Muscle Protein Synthesis, OCP, Resistance Exercise
Conditions
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.
Interventions
One leg will perform unilateral resistance exercise
OTHERControl Leg
One leg will serve as a non-exercise control
Sponsors
Natural Science and Engineering Research Council of Canada (NSERC)
McMaster University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention 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 OR each pill phase (active vs. placebo)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 30 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| Whole-body proteolysis | 6 days | The investigators will use 3-methylhistidine in urine to calculate the rate of whole-body myofibrillar protelysis |
Countries
Canada
Outcome results
None listed