Clinical trial NCT03046095: The Regulation of Human Skeletal Muscle Mass by Contractile Perturbation
Official title: The Regulation of Human Skeletal Muscle Mass by Contractile Perturbation
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Muscle Atrophy
Disuse Atrophy (Muscle) of Lower Leg
Keywords: Muscle Hypertrophy
Muscle Atrophy
Resistance Training
Immobilization
Lead sponsor: McMaster University
Sponsor class: OTHER
First posted: 2017-02-08
Enrollment: 14
Sex: MALE
Minimum age (years): 18
Maximum age (years): 30
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: SINGLE_GROUP
Intervention model description: The model will be a within-subject intervention. Each subject will have one leg randomized to unilateral resistance exercise (for 10 weeks) and the other to immobilization (for the last 2 weeks of the study).
Primary purpose: BASIC_SCIENCE

Brief summary: It is well known that periods of weight training lead to increases in skeletal muscle size and strength. In contrast, periods of inactivity such as bed rest or immobilization result in losses of skeletal muscle size and strength. However, individuals experience variable magnitudes of muscle size change in response to changes in mechanical tension, such that certain individuals experience large changes in muscle mass whereas others do not. What is not currently known, and will be the primary goal of the present investigation, is to determine whether individuals who gain the most muscle mass with exercise training also lose the most muscle when they are immobilized. The investigators hypothesize that individuals who gain the most muscle with training will also lose the most with immobilization.

Detailed description: Resistance exercise, paired with protein ingestion, leads to the accretion of muscle proteins that over time results in the augmentation of muscle size and muscle strength. By virtue of its ability to stimulate increases in muscle size and strength, resistance exercise is an effective method that can be used by healthcare practitioners to promote the recovery of lost muscle mass resulting from a period of immobilization (resulting from broken bones, elective surgery, etc.). However, while exercise in general is an effective therapeutic strategy to combat muscle loss and frailty, the extent to which individuals respond to resistance exercise is highly variable. Some individuals exhibit large changes in muscle size (high responders) whereas other exhibit little to no change (low responders). Thus, where as one resistance exercise program might be an appropriate treatment for one individual following disuse, another individual might require a greater stimulus and/or pharmaceutical assistance in order to fully recover. What is currently unknown is whether individuals who experience the most profound increases in skeletal muscle mass following resistance exercise also lose the most muscle upon limb immobilization. Answering this gap in our knowledge will be the primary goal of this study. The procurement of this knowledge will hopefully permit the development of individualized exercise programs that can be used to influence the recovery of skeletal muscle that is lost with inactivity and immobilization.

Eligibility criteria: Inclusion Criteria:

* Healthy
* Non-Smoker
* Do not heavily consume alcohol

Exclusion Criteria:

* Female
* Younger than 18, or older than 30 years
* use of anti-inflammatory or analgesic medication
* history of neuromuscular disorders
* family history of deep vein thrombosis
* regularly take part in structured physical exercise (greater than 2 days per week)
* take any medications known to influence protein metabolism

Primary outcomes:
measure: Muscle Cross Sectional Area
timeFrame: May 2017 - Dec 2017
measure: Leg Lean Mass
timeFrame: May 2017 - Dec 2017
Secondary outcomes:
measure: Skeletal Muscle Gene Expression
timeFrame: May 2017 - Dec 2017
Other outcomes:
Locations:
city: Hamilton
country: Canada
facility: Exercise Metabolism Research Laboratory, McMaster Univeristy
state: Ontario
Study officials:
affiliation: McMaster University
name: Stuart M Phillips, PhD
role: PRINCIPAL_INVESTIGATOR
References: