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

NCT07178353 | Recruiting

• 1 other identifier: 6043735
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

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

Conditions

Muscular Atrophy; Insulin Resistance; Muscle Protein Synthesis

Keywords

magnetic resonance imaging; muscle protein syntheis; muscle disuse atrophy; bedrest; skeletal muscle; insulin sensitivity

Outcome Measures

Primary Outcomes (1)

• Quadriceps muscle volume

  Quadriceps muscle volume will be assessed by magnetic resonance imaging.

  Day 0, and 5

Secondary Outcomes (18)

• Muscle strength

  Day -14, -9, and 5

• Knee extensor power

  Day -14, -9, and 5

• Muscle fatiguability

  Day -14, -9, and 5

• Muscle cross-sectional area

  Day 0 and 5

• Muscle protein synthesis

  Day -5 to 0, day 0 to 1, day 0 to 3, day 0 to 5, day 1 to 3, day 1 to 5, and day 3 to 5.

Study Arms (1)

Experimental: Bedrest

EXPERIMENTAL

19 day study period, consisting of baseline testing, 5 days of free-living (habitual daily activities) immediately followed by 5 days of strict bedrest. Diet controlled and physical activity monitored for entire study period.

Other: Bedrest

Interventions

Bedrest OTHER

5 days of strict bedrest. Participants are allowed to sit up in bed, but will perform any bathing or bathroom activities in a wheelchair.

Also known as: Horizontal Bedrest

Experimental: Bedrest

Eligibility Criteria

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

You may qualify if:

• Males and females 18-30 years
• BMI between 18.5-28 kg/m2
• Weight stable (within ±2kg for 6 months)
• Generally healthy as assessed by medical and physical activity questionnaires
• recreationally active

You may not qualify if:

• a BMI \< 18.5 and \> 28 kg/m2
• the use of insulin to control blood glucose levels
• a history of any cardiovascular, respiratory, metabolic diseases, neuromuscular or bone-wasting diseases
• the use of any medication that may affect muscle protein turnover (e.g. androgen or anabolic hormone therapy, chemotherapy)
• a (family) history of thrombosis, platelet or coagulation disorders, or antiplatelet therapy and the use of anticoagulant medications
• the presence of any unremoved, or partially removed metals underneath the skin
• a history of head or eye injury involving metal fragments
• have some type of implanted electrical device (such as a cardiac pacemaker or neurostimulator)
• have implanted metal objects as a result of surgery, such as artificial joints, aneurysm clips, metal staples
• are, or may be, pregnant
• are wearing metal braces on their teeth.

Sponsors & Collaborators

• Queen's University: lead
• Canadian Institutes of Health Research (CIHR): collaborator

Study Sites (1)

Queen's Univeristy

Kingston, Ontario, K7L 3N6, Canada

RECRUITING

MeSH Terms

Conditions

Muscular Atrophy; Insulin Resistance; Muscular Disorders, Atrophic

Interventions

Bed Rest

Condition Hierarchy (Ancestors)

Neuromuscular Manifestations; Neurologic Manifestations; Nervous System Diseases; Atrophy; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Hyperinsulinism; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Muscular Diseases; Musculoskeletal Diseases; Neuromuscular Diseases

Intervention Hierarchy (Ancestors)

Therapeutics

Study Officials

• Chris McGlory, PhD.

  Queen's University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Chris McGlory, PhD.

CONTACT

6135336000; chris.mcglory@queensu.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Model Details: This study uses a within-subjects, repeated measures design. Single-arm study. Participants will complete a 5-day free-living, baseline testing period, before undergoing 5 days of strict horizontal bedrest.

Study Record Dates

• First Submitted: September 10, 2025
• First Posted: September 17, 2025
• Study Start: September 1, 2025
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): June 1, 2027
• Last Updated: September 22, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)