Muscle DisuseNCT07069426
Muscle Response to Different Amounts of Dietary Protein During Leg Immobilization
A study testing 20 grams protein and 40 grams protein in people with Muscle Disuse and Muscle Disuse Atrophy, run by United States Army Research Institute of Environmental Medicine at 1 site in United States.
Trial summary
Individuals who sustain musculoskeletal injuries (MSKI) can experience a rapid loss of muscle mass due to declines in muscle loading and activation that occur post-injury (i.e., disuse atrophy). Read more about this study
- Who is it for?
- Ages 17 to 39 yearsHealthy volunteers can take part
- Conditions the study is for
- Muscle Disuse, Muscle Disuse Atrophy
- What is being tested?
- 20 grams protein and 40 grams protein
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 28 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Sep 2025to Sep 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 17 to 39 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- Men and women aged 18-39 years (17-39 years if military personnel)
- Body mass index (BMI) between 18.5-32 kg/m2
- Routinely participate in aerobic and/or resistance exercise at least 2 days per week.
- Willing to refrain from alcohol, smoking, smokeless nicotine products (includes e-cigarettes, vaping, chewing tobacco), and dietary supplements (i.e., vitamin D, probiotics) 24 hours before and during immobilization and final testing day.
- Willing to only consume caffeine products provided by study staff during the study.
- Supervisor approval for federal civilian employees and non-SRV active-duty military personnel stationed at NSSC.
- Biological females must have normal menstrual cycles between 26-32 days in duration; 5 menstrual cycles within the past 6 months; or on continuous hormonal contraception (i.e., IUD or oral contraceptives without placebo).
Who cannot join
- Musculoskeletal injuries that may interfere with the safe use of crutches.
- Personal or family history of thrombosis, or prior diagnosis of deep vein thrombosis (DVT) or pulmonary embolism (PE).
- Metabolic or cardiovascular abnormalities, gastrointestinal disorders, neuromuscular disorders, lower-limb amputation, or muscle/bone wasting disorders (e.g., diabetes, cardiovascular disease, Crohn's disease, etc.).
- Taking medication that affects macronutrient utilization (i.e., statins, corticosteroids, weight loss medications such as Ozempic, etc.).
- Significantly abnormal blood clotting as determined by USARIEM Office of Medical Oversight (OMSO) or home duty station medical support (HMS).
- Allergy to lidocaine (or similar local anesthetic).
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- Present condition of alcoholism, anabolic steroid use, or other substance abuse issues as determined by OMSO or HMS.
- Blood donation within 8-wk of beginning the study.
- Pregnant, trying to become pregnant, and/or breastfeeding (results of urine pregnancy test and self-report for breastfeeding will be obtained before body composition testing).
- Unwilling or unable to consume study diets or foods provided due to personal preference and/or food allergies.
- Unwilling or unable to adhere to study physical restrictions (i.e., no structured physical activity or recreational activity beyond activities of daily living) 24 hours before and during immobilization, and the final testing day.
- Unwilling or unable to keep the knee brace on and walk with crutches during the immobilization phase.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
US Army Research Institute of Environmental Medicine
Natick, Massachusetts, 01760
Emily Howard, PhD, 508-206-2309, emily.e.howard14.civ@health.mil
Emily E Howard, PhD
About this study
Official title: The Effects of Varying Protein Intakes on Muscle Protein Synthesis During Injury-Mediated Muscle Disuse
Individuals who sustain musculoskeletal injuries (MSKI) can experience a rapid loss of muscle mass due to declines in muscle loading and activation that occur post-injury (i.e., disuse atrophy). Loss of muscle under these conditions is attributed to a persistent negative net muscle protein balance (muscle protein synthesis [MPS] < muscle protein breakdown) that results, in part, from declines in postprandial MPS (i.e., anabolic resistance). Nutritional interventions that enhance postprandial MPS may be used to overcome disuse-induced anabolic resistance and preserve muscle mass to accelerate recovery and improve recovery outcomes. While supplemental protein has been explored as a potential countermeasure to disuse-induce anabolic resistance, the observed efficacy of such interventions has been mixed. Equivocal findings across studies may be attributed, in part, to an insufficient understanding of what constitutes an effective protein-based intervention. Importantly, no study to date has determined an optimal protein dose for overcoming disuse-induce anabolic resistance, or if there is a threshold for maximally stimulating postprandial MPS under disuse conditions. Therefore, the objective of this work is to determine rates of MPS at rest and in response to standard (20 g) or high (40 g) doses of whey protein during knee immobilization (DISUSE) compared with standard activity (ACTIVE)
Read the detailed description
Healthy, recreationally active men and women will complete this randomized, double-blind, parallel study. Muscle disuse will be implemented for five days using a unilateral leg immobilization model with one leg assigned to immobilization (DISUSE) and the contralateral leg used as a control (ACTIVE). Immobilization will be implemented with a rigid knee brace fixed at ~60° of flexion and participants will ambulate using crutches. Diets will be standardized during the immobilization phase. Participants will complete a protein feeding study at the end of immobilization consisting of primed, continuous stable isotope infusions, serial blood draws, and muscle biopsies. MPS will be assessed in both the DISUSE and ACTIVE legs in response to standard (20 g) or high (40 g) doses of whey protein. Findings from this work will directly inform the development of targeted nutritional countermeasures for overcoming disuse-induced anabolic resistance and preserving muscle mass after MSKI to optimize physical performance recovery.
- Conditions
- Muscle Disuse, Muscle Disuse Atrophy
- Being tested
- 20 grams protein, 40 grams protein
- Keywords
- muscle protein synthesis, muscle disuse, muscle disuse atrophy, immobilization, anabolic resistance, dose-response
- Medical subject headings
- Muscular Disorders, Atrophic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
20 grams proteinDietary supplement
20 grams of whey protein provided as beverage
40 grams proteinDietary supplement
40 grams of whey protein provided as beverage
| Study group | Role | What they receive |
|---|---|---|
| Standard Protein Dose | Active comparator | Participants will consume 20 g of whey protein after 5 days of muscle disuse Receives: Dietary Supplement: 20 grams protein |
| High Protein Dose | Active comparator | Participants will consume 40 g of whey protein after 5 days of muscle disuse Receives: Dietary Supplement: 40 grams protein |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rates of postabsorptive and postprandial muscle protein synthesis assessed using 2H5-Phenylalanine stable isotope methodologies.
Postabsorptive and postprandial muscle protein synthesis in response to 20 or 40 g of whey protein determined using 2H5-Phenylalanine stable isotope methodologies and expressed as fractional synthetic rate (FSR).
Measured: After 5 days of muscle disuse
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jul 2025
- Study start1 Sep 2025
- Primary completionSep 2026 (estimated)
- Study completionSep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Muscle DisuseStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 28 participants (estimated)
Sponsor and investigators
- Lead sponsor
- United States Army Research Institute of Environmental Medicine
- Sponsor type
- US federal agency
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07069426
- Sponsor's protocol ID
- 25-04H
- Other IDs
- MO240092
- Status last verified
- Sep 2025
- First submitted
- 21 May 2025
- Last updated
- 11 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared.
Study at a glance
From the registry record, last updated by the sponsor on 11 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Varying Protein Intakes on Muscle Protein Synthesis During Injury-Mediated Muscle Disuse
- ClinicalTrials.gov ID
- NCT07069426
- Acronym / sponsor ID
- 25-04H
- Conditions
- Muscle Disuse, Muscle Disuse Atrophy
- Keywords
- muscle protein synthesis, muscle disuse, muscle disuse atrophy, immobilization, anabolic resistance, dose-response
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 28 participants (estimated)
- Lead sponsor
- United States Army Research Institute of Environmental MedicineUS federal agency
- Study start
- 1 Sep 2025 (actual)
- Primary completion
- Sep 2026 (estimated)
- Study completion
- Sep 2026 (estimated)
- First posted
- 16 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Individuals who sustain musculoskeletal injuries (MSKI) can experience a rapid loss of muscle mass due to declines in muscle loading and activation that occur post-injury (i.e., disuse atrophy). Loss of muscle under these conditions is attributed to a persistent negative net muscle protein balance (muscle protein synthesis [MPS] < muscle protein breakdown) that results, in part, from declines in postprandial MPS (i.e., anabolic resistance). Nutritional interventions that enhance postprandial MPS may be used to overcome disuse-induced anabolic resistance and preserve muscle mass to accelerate recovery and improve recovery outcomes. While supplemental protein has been explored as a potential countermeasure to disuse-induce anabolic resistance, the observed efficacy of such interventions has been mixed. Equivocal findings across studies may be attributed, in part, to an insufficient understanding of what constitutes an effective protein-based intervention. Importantly, no study to date has determined an optimal protein dose for overcoming disuse-induce anabolic resistance, or if there is a threshold for maximally stimulating postprandial MPS under disuse conditions. Therefore, the objective of this work is to determine rates of MPS at rest and in response to standard (20 g) or high (40 g) doses of whey protein during knee immobilization (DISUSE) compared with standard activity (ACTIVE)
Detailed description
Healthy, recreationally active men and women will complete this randomized, double-blind, parallel study. Muscle disuse will be implemented for five days using a unilateral leg immobilization model with one leg assigned to immobilization (DISUSE) and the contralateral leg used as a control (ACTIVE). Immobilization will be implemented with a rigid knee brace fixed at ~60° of flexion and participants will ambulate using crutches. Diets will be standardized during the immobilization phase. Participants will complete a protein feeding study at the end of immobilization consisting of primed, continuous stable isotope infusions, serial blood draws, and muscle biopsies. MPS will be assessed in both the DISUSE and ACTIVE legs in response to standard (20 g) or high (40 g) doses of whey protein. Findings from this work will directly inform the development of targeted nutritional countermeasures for overcoming disuse-induced anabolic resistance and preserving muscle mass after MSKI to optimize physical performance recovery.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Standard Protein Dose | Active comparator | Dietary Supplement: 20 grams proteinParticipants will consume 20 g of whey protein after 5 days of muscle disuse |
| High Protein Dose | Active comparator | Dietary Supplement: 40 grams proteinParticipants will consume 40 g of whey protein after 5 days of muscle disuse |
Who may qualify
- Ages
- 17 to 39 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (7 listed)
- Men and women aged 18-39 years (17-39 years if military personnel)
- Body mass index (BMI) between 18.5-32 kg/m2
- Routinely participate in aerobic and/or resistance exercise at least 2 days per week.
- Willing to refrain from alcohol, smoking, smokeless nicotine products (includes e-cigarettes, vaping, chewing tobacco), and dietary supplements (i.e., vitamin D, probiotics) 24 hours before and during immobilization and final testing day.
- Willing to only consume caffeine products provided by study staff during the study.
Key exclusion criteria (12 listed)
- Musculoskeletal injuries that may interfere with the safe use of crutches.
- Personal or family history of thrombosis, or prior diagnosis of deep vein thrombosis (DVT) or pulmonary embolism (PE).
- Metabolic or cardiovascular abnormalities, gastrointestinal disorders, neuromuscular disorders, lower-limb amputation, or muscle/bone wasting disorders (e.g., diabetes, cardiovascular disease, Crohn's disease, etc.).
- Taking medication that affects macronutrient utilization (i.e., statins, corticosteroids, weight loss medications such as Ozempic, etc.).
- Significantly abnormal blood clotting as determined by USARIEM Office of Medical Oversight (OMSO) or home duty station medical support (HMS).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 20 grams protein20 grams of whey protein provided as beverage | Dietary supplement | Standard Protein Dose |
| 40 grams protein40 grams of whey protein provided as beverage | Dietary supplement | High Protein Dose |
Primary outcome
Rates of postabsorptive and postprandial muscle protein synthesis assessed using 2H5-Phenylalanine stable isotope methodologies.
Time frame: After 5 days of muscle disuse
Postabsorptive and postprandial muscle protein synthesis in response to 20 or 40 g of whey protein determined using 2H5-Phenylalanine stable isotope methodologies and expressed as fractional synthetic rate (FSR).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Sep 2025.
- Individual participant dataSharing planned: No. Individual participant data will not be shared.
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Mitigating Neural Hypoexcitability and Weakness During Disuse in Women
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Sex-specific Determinants of Early-phase Recovery From Skeletal Muscle Disuse
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Cross-education of Skill and Strength in Healthy People Subjected to an Upper-limb Disuse Model
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing 20 grams protein and 40 grams protein in people with Muscle Disuse and Muscle Disuse Atrophy, run by United States Army Research Institute of Environmental Medicine at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 11 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Emily E Howard, PhD (508-206-2309, emily.e.howard14.civ@health.mli), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rates of postabsorptive and postprandial muscle protein synthesis assessed using 2H5-Phenylalanine stable isotope methodologies. (time frame: After 5 days of muscle disuse). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Sep 2025.