High AltitudeHAMRNCT06392373
High Altitude Muscle Recovery
A study testing CHO+PRO and CHO in people with High Altitude, run by United States Army Research Institute of Environmental Medicine at 1 site in United States.
Trial summary
To understand alterations in glycogen and molecular regulation of skeletal muscle glucose uptake, glycogen synthesis, and muscle protein recovery when consuming CHO (glucose) or CHO+PRO (glucose + whey) post-exercise during unacclimatized high altitude exposure, randomized crossover double blinded studies will be… Read more about this study
- Who is it for?
- Ages 18 to 39 yearsHealthy volunteers can take part
- Conditions the study is for
- High Altitude
- What is being tested?
- CHO+PRO and CHO
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 8 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Oct 2023to 19 Dec 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 18 to 39 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Men and women aged 18 - 39 years
- Physically active (exercise minimum 2-4 days per week)
- Have supervisor approval (permanent party military and civilians at NSSC)
- Willing to refrain from alcohol, nicotine products and dietary supplement use during the study
- Females must have normal menstrual cycles between 26-32 days in duration; 5 menstrual cycles within the past 6 months; or using oral/hormonal contraceptive use which contains low-dose estrogen/progesterone to maintain continuous levels throughout the 28-day cycle (i.e., no placebos)
- Only consume caffeine products during the study if provided by study staff
Who cannot join
- Born at altitudes greater than 2,100 m (Subjects will inform the study team if they were born in Eagar AZ, Mammoth Lakes CA, CO, NM, UT, or WY).
- Musculoskeletal injuries that compromise exercise capability
- Metabolic or cardiovascular abnormalities, or gastrointestinal disorders (e.g. hypothyroidism, cardiovascular disease, Crohn's disease, etc.)
- Taking medication that affects macronutrient metabolism and/or the ability to participate in strenuous exercise (e.g. thyroxine, beta blockers, insulin etc.)
- Living in areas that are more than 1,200 m, or traveled to areas that are more than 1,200 m for five days or more within 2 months of data collection (e.g. Idaho Falls, ID; Denver, CO; etc.)
- Prior diagnosis of high-altitude pulmonary edema or high-altitude cerebral edema
Show all 14Show fewer
- Presence of asthma or respiratory tract infections
- Smoking or vaping (other forms of nicotine users, i.e., chewing tobacco will not be excluded; individuals who quit smoking or vaping for more than 90 days may be included)
- Taking medications that interfere with oxygen delivery and transport (e.g. albuterol, EPO, etc.)
- Hematocrit (HCT) <41% and Hemoglobin (HBG) <13.5 g/dL(Males), HCT <36% and HBG <12.0 g/dL (Females), and Sickle Cell Anemia/Trait
- Whole blood donation within 8 weeks of the study
- Unwilling or unable to only consume study diets or foods provided due to personal preference, dietary restrictions, and/or food allergies
- Unwilling or unable to adhere to study physical restrictions (abstain from exercise or recreational activities i.e., pick-up basketball during the study procedures)
- Pregnant, trying to become pregnant, and/or breastfeeding (results of urine pregnancy test or self-report for breastfeeding will be obtained before body composition testing)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Skeletal Muscle Recovery From Aerobic Exercise During Acute High Altitude Exposure When Consuming Carbohydrate Compared to Carbohydrate Plus Protein
To understand alterations in glycogen and molecular regulation of skeletal muscle glucose uptake, glycogen synthesis, and muscle protein recovery when consuming CHO (glucose) or CHO+PRO (glucose + whey) post-exercise during unacclimatized high altitude exposure, randomized crossover double blinded studies will be conducted in the hypobaric/hypoxic chamber at USARIEM Table 1. Briefly, the study consists of a 2 day baseline period at SL followed by two, 3 day trial periods (with the 3rd day being a testing day) at HA. The baseline is separated from trial 1 for a least a day, and trial 1 \& 2 separated by at least 4 days. Volunteers will consume CHO (glucose) or CHO+PRO (glucose + whey) drinks post-exercise during unacclimatized high altitude exposure during the two trial periods. The order of the drinks will be randomized (using a random number generator such as randomizer.org) and kept by a study staff not directly involved in data collection to maintain blinding.
Read the detailed description
Dietary strategies that restore muscle glycogen and promote muscle repair and remodeling in recovery from exercise are needed to protect muscle mass and sustain performance during strenuous military operations conducted at high altitude (HA; > 2500 m elevation). However, most military personnel who operate at HA are native lowlanders and, thus, unacclimatized to the hypoxemia that occurs upon initial HA exposure. We demonstrated that acute HA exposure (within 5 hours) dysregulates peripheral glucose uptake and inhibits post-exercise muscle anabolism in lowlanders sojourning at 4,300 m. Our results suggest that traditional recommendations to consume solely carbohydrate immediately post-exercise to facilitate muscle recovery may be inadequate for lowlanders exercising within the first several hours of HA exposure. In a recent meta-analysis by our group, we reported that the effects of ingesting carbohydrate (CHO) compared to isocaloric carbohydrate plus protein (CHO+PRO) on muscle glycogen repletion were equivocal, yet the combined macronutrient blend confers an additional metabolic advantage than CHO alone because it stimulates muscle repair/remodeling by upregulating anabolic signaling and protein synthesis. Our findings suggest post-exercise CHO intake can be reduced in place of an isocaloric amount of PRO when exercising at HA without comprising glycogen repletion. However, whether CHO+PRO promotes post-exercise glycogen repletion and muscle anabolism as compared to CHO alone when peripheral glucose uptake and anabolic signaling are dysregulated with acute HA exposure has not been determined. This study aims to determine the effects of ingesting CHO or an isocaloric amount of CHO+PRO post-aerobic exercise on glycogen synthesis, molecular regulation of glucose uptake, storage, and muscle protein synthesis during acute HA exposure. This study will employ a randomized crossover double-blinded design and be conducted in the hypobaric/hypoxic chamber at USARIEM. A total of 10 healthy, physically active men and women between the ages of 18-39 years will be studied. Following 48 hours of controlled exercise and diet to normalize muscle glycogen stores, volunteers will report to the laboratory after a 10-h overnight fast. After a muscle biopsy is taken from the vastus lateralis at baseline, volunteers will be brought to HA (460 mmHg) conditions within the hypobaric/hypoxic chamber at USARIEM and complete a standardized glycogen depletion protocol on a cycle ergometer. After completing the glycogen depletion exercise a second muscle biopsy will be taken. Volunteers will then consume 1.2 g CHO/kg/h or 0.9 g CHO/kg/h + 0.3 g PRO/kg/h over a 3-h recovery period. A third and fourth biopsy will be taken 4 and 6 hours into recovery to characterize the molecular regulation of glucose uptake, glycogen synthesis, and muscle protein synthesis over time. Serial blood draws will be collected during each trial to assess endocrine and circulating substrate responses in CHO and CHO+PRO. Trials will be separated by a minimum of 4 days. The primary risks associated with this study include those associated with acute hypobaric hypoxia, exercise, muscle biopsies, and blood draws.
- Conditions
- High Altitude
- Being tested
- CHO+PRO, CHO
- Medical subject headings
- Altitude Sickness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CHO+PRODietary supplement
0.9 g CHO/kg/hr + 0.3 g PRO/kg/hr
CHODietary supplement
1.2 g CHO/kg/hr
| Study group | Role | What they receive |
|---|---|---|
| Carbohydrate plus protein | Experimental | Study beverages consumed over the initial 3 hours recovery phase from aerobic exercise, consuming 0.9g CHO/kg/hr + 0.3g PRO/kg/hr during high altitude exposure. Receives: Dietary Supplement: CHO+PRO |
| Carbohydrate | Active comparator | Study beverages consumed over the initial 3 hours recovery phase from aerobic exercise, consuming1.2g CHO/kg/hr during high altitude exposure. Receives: Dietary Supplement: CHO |
What is being measured
The primary outcome is the main question the study is designed to answer.
Muscle Glycogen Concentrations
Determine the effects of of consuming a CHO (1.2 g CHO/kg/hr) compared to an isocaloric CHO+PRO (0.9 g CHO/kg/hr + 0.3 g PRO/kg/hr) supplement on post exercise muscle glycogen concentrations (umol/kg dry muscle weight) during the initial 6 hours of aerobic exercise recovery
Measured: 6 hours
Phosphorylation status of rpS6
Determine the effects of of consuming a CHO (1.2 g CHO/kg/hr) compared to an isocaloric CHO+PRO (0.9 g CHO/kg/hr + 0.3 g PRO/kg/hr) supplement on post exercise muscle the fold change in the phosphorylation of rpS6 during the initial 6 hours of aerobic exercise recovery
Measured: 6 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Apr 2024
- Study start1 Oct 2023
- Primary completion19 Dec 2023
- Study completion19 Dec 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for High AltitudeStudies 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Double blinded randomized crossover design
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 8 participants (actual)
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
- NCT06392373
- Sponsor's protocol ID
- 23-04H
- Acronym
- HAMR
- Status last verified
- Mar 2025
- First submitted
- 25 Apr 2024
- Last updated
- 20 Mar 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Skeletal Muscle Recovery From Aerobic Exercise During Acute High Altitude Exposure When Consuming Carbohydrate Compared to Carbohydrate Plus Protein
- ClinicalTrials.gov ID
- NCT06392373
- Acronym / sponsor ID
- HAMR / 23-04H
- Conditions
- High Altitude
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 8 participants (actual)
- Lead sponsor
- United States Army Research Institute of Environmental MedicineUS federal agency
- Study start
- 1 Oct 2023 (actual)
- Primary completion
- 19 Dec 2023 (actual)
- Study completion
- 19 Dec 2023 (actual)
- First posted
- 30 Apr 2024 (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.
To understand alterations in glycogen and molecular regulation of skeletal muscle glucose uptake, glycogen synthesis, and muscle protein recovery when consuming CHO (glucose) or CHO+PRO (glucose + whey) post-exercise during unacclimatized high altitude exposure, randomized crossover double blinded studies will be conducted in the hypobaric/hypoxic chamber at USARIEM Table 1. Briefly, the study consists of a 2 day baseline period at SL followed by two, 3 day trial periods (with the 3rd day being a testing day) at HA. The baseline is separated from trial 1 for a least a day, and trial 1 \& 2 separated by at least 4 days. Volunteers will consume CHO (glucose) or CHO+PRO (glucose + whey) drinks post-exercise during unacclimatized high altitude exposure during the two trial periods. The order of the drinks will be randomized (using a random number generator such as randomizer.org) and kept by a study staff not directly involved in data collection to maintain blinding.
Detailed description
Dietary strategies that restore muscle glycogen and promote muscle repair and remodeling in recovery from exercise are needed to protect muscle mass and sustain performance during strenuous military operations conducted at high altitude (HA; > 2500 m elevation). However, most military personnel who operate at HA are native lowlanders and, thus, unacclimatized to the hypoxemia that occurs upon initial HA exposure. We demonstrated that acute HA exposure (within 5 hours) dysregulates peripheral glucose uptake and inhibits post-exercise muscle anabolism in lowlanders sojourning at 4,300 m. Our results suggest that traditional recommendations to consume solely carbohydrate immediately post-exercise to facilitate muscle recovery may be inadequate for lowlanders exercising within the first several hours of HA exposure. In a recent meta-analysis by our group, we reported that the effects of ingesting carbohydrate (CHO) compared to isocaloric carbohydrate plus protein (CHO+PRO) on muscle glycogen repletion were equivocal, yet the combined macronutrient blend confers an additional metabolic advantage than CHO alone because it stimulates muscle repair/remodeling by upregulating anabolic signaling and protein synthesis. Our findings suggest post-exercise CHO intake can be reduced in place of an isocaloric amount of PRO when exercising at HA without comprising glycogen repletion. However, whether CHO+PRO promotes post-exercise glycogen repletion and muscle anabolism as compared to CHO alone when peripheral glucose uptake and anabolic signaling are dysregulated with acute HA exposure has not been determined. This study aims to determine the effects of ingesting CHO or an isocaloric amount of CHO+PRO post-aerobic exercise on glycogen synthesis, molecular regulation of glucose uptake, storage, and muscle protein synthesis during acute HA exposure. This study will employ a randomized crossover double-blinded design and be conducted in the hypobaric/hypoxic chamber at USARIEM. A total of 10 healthy, physically active men and women between the ages of 18-39 years will be studied. Following 48 hours of controlled exercise and diet to normalize muscle glycogen stores, volunteers will report to the laboratory after a 10-h overnight fast. After a muscle biopsy is taken from the vastus lateralis at baseline, volunteers will be brought to HA (460 mmHg) conditions within the hypobaric/hypoxic chamber at USARIEM and complete a standardized glycogen depletion protocol on a cycle ergometer. After completing the glycogen depletion exercise a second muscle biopsy will be taken. Volunteers will then consume 1.2 g CHO/kg/h or 0.9 g CHO/kg/h + 0.3 g PRO/kg/h over a 3-h recovery period. A third and fourth biopsy will be taken 4 and 6 hours into recovery to characterize the molecular regulation of glucose uptake, glycogen synthesis, and muscle protein synthesis over time. Serial blood draws will be collected during each trial to assess endocrine and circulating substrate responses in CHO and CHO+PRO. Trials will be separated by a minimum of 4 days. The primary risks associated with this study include those associated with acute hypobaric hypoxia, exercise, muscle biopsies, and blood draws.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Double blinded randomized crossover design
| Arm | Type | Receives |
|---|---|---|
| Carbohydrate plus protein | Experimental | Dietary Supplement: CHO+PROStudy beverages consumed over the initial 3 hours recovery phase from aerobic exercise, consuming 0.9g CHO/kg/hr + 0.3g PRO/kg/hr during high altitude exposure. |
| Carbohydrate | Active comparator | Dietary Supplement: CHOStudy beverages consumed over the initial 3 hours recovery phase from aerobic exercise, consuming1.2g CHO/kg/hr during high altitude exposure. |
Who may qualify
- Ages
- 18 to 39 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Men and women aged 18 - 39 years
- Physically active (exercise minimum 2-4 days per week)
- Have supervisor approval (permanent party military and civilians at NSSC)
- Willing to refrain from alcohol, nicotine products and dietary supplement use during the study
- Females must have normal menstrual cycles between 26-32 days in duration; 5 menstrual cycles within the past 6 months; or using oral/hormonal contraceptive use which contains low-dose estrogen/progesterone to maintain continuous levels throughout the 28-day cycle (i.e., no placebos)
Key exclusion criteria (14 listed)
- Born at altitudes greater than 2,100 m (Subjects will inform the study team if they were born in Eagar AZ, Mammoth Lakes CA, CO, NM, UT, or WY).
- Musculoskeletal injuries that compromise exercise capability
- Metabolic or cardiovascular abnormalities, or gastrointestinal disorders (e.g. hypothyroidism, cardiovascular disease, Crohn's disease, etc.)
- Taking medication that affects macronutrient metabolism and/or the ability to participate in strenuous exercise (e.g. thyroxine, beta blockers, insulin etc.)
- Living in areas that are more than 1,200 m, or traveled to areas that are more than 1,200 m for five days or more within 2 months of data collection (e.g. Idaho Falls, ID; Denver, CO; etc.)
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 |
|---|---|---|
| CHO+PRO0.9 g CHO/kg/hr + 0.3 g PRO/kg/hr | Dietary supplement | Carbohydrate plus protein |
| CHO1.2 g CHO/kg/hr | Dietary supplement | Carbohydrate |
Primary outcome
Muscle Glycogen Concentrations
Time frame: 6 hours
Determine the effects of of consuming a CHO (1.2 g CHO/kg/hr) compared to an isocaloric CHO+PRO (0.9 g CHO/kg/hr + 0.3 g PRO/kg/hr) supplement on post exercise muscle glycogen concentrations (umol/kg dry muscle weight) during the initial 6 hours of aerobic exercise recovery
Phosphorylation status of rpS6
Time frame: 6 hours
Determine the effects of of consuming a CHO (1.2 g CHO/kg/hr) compared to an isocaloric CHO+PRO (0.9 g CHO/kg/hr + 0.3 g PRO/kg/hr) supplement on post exercise muscle the fold change in the phosphorylation of rpS6 during the initial 6 hours of aerobic exercise recovery
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Mar 2025.
- Individual participant dataSharing planned: No
Related trials for High Altitude
Not yet recruiting
Effect of High-flow Nasal Cannula Oxygenation on the Incidence of Hypoxemia During Painless Gastrointestinal Endoscopy in Patients at High Risk for Obstructive Sleep Apnea Syndrome in High-altitude Regions
Hypoxemia, Gastric Cancer (Diagnosis)
Not yet recruitingObservational study
Optimization of Two-Indicator Screening Protocol for Neonatal Congenital Heart Disease at High Altitude
Neonatal Congenital Heart Disease
Not yet recruiting
Assessment of Total Pulmonary Resistance sPAP/CO Between High Altitude HA vs. Sea Level LA in Patients With Pulmonary Arterial Hypertension PAH
Pulmonary Arterial Hypertension (PAH), Pulmonary Vascular Disease
Not yet recruiting
Assessment of Lung Function (Lufu) at Sea Level LA vs. High Altitude HA in Patients With Pulmonary Arterial Hypertension PAH
Pulmonary Arterial Hypertension (PAH), Pulmonary Vascular Disease
Not yet recruiting
Assessment of Total Pulmonary Resistance sPAP/CO Between Sea Level LA vs. High Altitude HA After Re-ascent in Healthy Individuals
High Altitude, Healthy
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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing CHO+PRO and CHO in people with High Altitude, 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 6 inclusion and 14 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: finished, as of the sponsor's last update on 20 Mar 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Muscle Glycogen Concentrations (time frame: 6 hours). The study lists 2 primary outcomes in all. 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 20 Mar 2025.