Evaluating Changes in Skeletal Muscle Proteins Following Resistance Exercise and Single-Leg Disuse

NCT06350591 | Completed

• 1 other identifier: 6038674
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

Skeletal muscle plays a critical role in supporting human health. Beyond its role in providing the force to move, skeletal muscle accounts for a large proportion of metabolic rate, glucose disposal, and amino acid storage. Skeletal muscle is dynamically regulated by environmental stimuli, such as loading (i.e., resistance training\]) and unloading (i.e., disuse atrophy) as well as the intake of essential amino acids (EAAs). However, the precise mechanisms that regulate skeletal muscle mass in response to various conditions (e.g., EAA supplementation, resistance training, and unloading) are not completely understood. Therefore, concerted efforts to better understand the mechanisms regulating skeletal muscle size are needed that aid in the development of therapeutic interventions to combat age, disease, and disuse related muscular atrophy.

Conditions

Healthy; Skeletal Muscle Atrophy; Skeletal Muscle Hypertrophy

Outcome Measures

Primary Outcomes (2)

• Changes in average rates of muscle synthesis

  Skeletal muscle amino acids will be isolated and derivatized. Deuterium enrichment into protein-bound alanine will be measured using Gas chromatography-Pyrolysis-Isotope Ratio Mass Spectrometry

  -2, 0 (-4, 0, and 4 hours), and 10 days

• Dynamic proteomic profiling

  Skeletal muscle lysates containing \~100 ug protein will be digested using sequencing-grade trypsin, and analyzed, via UPLC-QTOF-MS. This will enable the quantification of changes in individual protein abundance, and rates of synthesis and breakdown.

  -2, 0, and 10 days

Secondary Outcomes (3)

• Protein expression (phosphorylation and content) of novel and known targets implicated in protein translation and mitochondrial-related protein expression

  0 (-4, 0, and 4 hours), and 10 days

• Muscle torque

  -6 and 10 days

• Quadriceps skeletal muscle volume

  0 and 10 days

Study Arms (2)

Immobilization

EXPERIMENTAL

Participants will undergo 10 days of unilateral immobilization whereby a leg will remain in 60 degrees of flexion with the use of a brace. All participants will complete this protocol.

Other: Immobilization

Resistance Training

EXPERIMENTAL

Participants will undergo 4 sessions of unilateral resistance training over a 10 day period (the resistance training protocol will include 3 sets of 8-12 reps of leg press and leg extension). All participants will complete this protocol. On day 0, participants will be asked to undergo a bout of unilateral resistance exercise, and the investigators will assess the acute response to exercise + protein feeding (via EAA supplement).

Other: Resistance training

Interventions

Immobilization OTHER

single-leg immobilization

Immobilization

Resistance training OTHER

Leg extension and leg press; 3 sets of 8-12 reps

Resistance Training

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Females 18-30 years
• BMI between 18-28 kg/m2
• ≥2 days per week of structured exercise
• Generally healthy as assessed by medical and physical activity questionnaires
• Participants not currently pregnant

You may not qualify if:

• Any muscular, neurological, respiratory, or metabolic disease including diabetes
• Any form of cancer currently or in the last 5 years
• Bleeding disorders or antiplatelet / anticoagulation therapy
• Currently taking fish oils or within the last 6 months
• Currently taking any form of steroid or within the last 3 months
• Inability to attain magnetic resonance imaging scans
• Known irregular responses to physical activity (e.g., shortness of breath, chest pain, dizziness, etc.)
• Any current illness
• Currently smoking or smoking within the last 6 months
• Currently pregnant
• Any concurrent medical, psychiatric, or orthopedic condition that, subject to investigators' discernment, would negatively affect the subject's ability to comply with the study requirements

Sponsors & Collaborators

• Queen's University: lead

Study Sites (1)

School of Kinesiology and Health Studies

Kingston, Ontario, K7L 3N6, Canada

Location

MeSH Terms

Conditions

Muscular Atrophy

Interventions

Immobilization; Resistance Training

Condition Hierarchy (Ancestors)

Neuromuscular Manifestations; Neurologic Manifestations; Nervous System Diseases; Atrophy; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms; Signs and Symptoms

Intervention Hierarchy (Ancestors)

Investigative Techniques; Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Patient Care; Therapeutics; Physical Therapy Modalities; Physical Conditioning, Human; Exercise; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: parallel, within-subject design

Study Record Dates

• First Submitted: January 16, 2024
• First Posted: April 5, 2024
• Study Start: April 1, 2024
• Primary Completion: March 11, 2025
• Study Completion: March 11, 2025
• Last Updated: October 1, 2025

Record last verified: 2024-10

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)