Human Skeletal Muscle Response to 5 Days of Bedrest in Young Adults

The goal of this intervention trial is to characterize skeletal muscle atrophy in healthy, young adults during short term bedrest. The main questions it aims to answer are: How much do skeletal muscle volume, strength, and fatigue resistance decline during bedrest? How much does whole-body insulin sensitivity change during bedrest? How do mitochondrial function and protein synthesis change during bedrest? Participants will undergo the following tests before and after a free-living control period and before and after a 5 day period of strict horizontal bedrest: * Magnetic resonance imaging of the thigh muscles * Strength testing of the thigh muscles * Insulin sensitivity testing in response to a mixed meal * Exogenous glucose oxidation in response to a mixed meal * Muscle biopsies from the thigh muscles * Blood samples

NCT Number	NCT07178353
Lead Sponsor	Queen's University Collaborators: Canadian Institutes of Health Research (CIHR)
Conditions	Muscular Atrophy, Insulin Resistance, Muscle Protein Synthesis
Enrollment	12 participants
Start Date	2025-09
Primary Completion	2026-06 (estimated)
Study Completion	2027-06 (estimated)
Updated on ClinicalTrials.gov	2025-09-22