HypercapniaNCT05116397
Influence of Graded Hypercapnia on Endurance Exercise Performance
A study testing Inspired gas in people with Hypercapnia, run by United States Army Research Institute of Environmental Medicine at 1 site in United States.
Trial summary
The aim of this randomized, single-blind, placebo-controlled crossover trial is to determine the effects of graded hypercapnia (0, 2, and 4% inspired CO2) on endurance performance. Twelve healthy and fit young adults (men and women) will complete this study. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Hypercapnia
- What is being tested?
- Inspired gas
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 15 participants
- Where
- 1 siteUnited States
- Study dates
- 10 Sep 2021to 14 Apr 2022
- 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 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Male or female, age 18-45
- In good health as determined by medical screening
- Passed his/her most recent Army Combat Fitness Test (ACFT) (Military Volunteers Only) or performs aerobic exercise at least 2 times per week and able to complete two mile run in ≤ 21 minutes (Civilian Volunteers)
- Willing to not participate in any exercise or drink alcoholic beverages for 24 hours before each study visit.
- Willing to not take part in any strenuous exercise in the 36 hours before each visit.
- Willing not to drink caffeine or eat food until after testing on familiarization and performance testing visits (visits 2-6).
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- Willing to maintain a similar dietary pattern in the 2 days before each familiarization and performance visits.
- Have supervisor approval if permanent party military or a federal employee at U.S. Army Natick Soldier System Center
- Able to speak and read English fluently
Who cannot join
- Females who are pregnant or planning to become pregnant during the study
- Taking dietary supplements, prescriptions, or over the counter medication, other than a contraceptive (unless approved by medical staff \& PI)
- Musculoskeletal injuries that compromise ability to run on a treadmill
- Abnormal blood count, presence of abnormal blood chemicals (hemoglobin S or sickle cell traits)
- Smokers or tobacco/nicotine users (unless have quit > 1 month prior)
- Any history of asthma
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- Current or recent respiratory tract or sinus infections (< 1 month prior)
- Allergy to skin adhesive
- Any history of migraine or recurrent headaches
- Any history of panic disorder
- Blood donation in the previous 8 weeks
- Positive Covid-19 test within the last month
Trial locations and contacts
1 site in 1 country.
About this study
The aim of this randomized, single-blind, placebo-controlled crossover trial is to determine the effects of graded hypercapnia (0, 2, and 4% inspired CO2) on endurance performance. Twelve healthy and fit young adults (men and women) will complete this study. Participants will perform experimental trials on 3 separate days (one each breathing 0%, 2%, and 4% inspired CO2-all with normal 21% oxygen). During each trial, they will perform 10 minutes of submaximal treadmill walking exercise and then complete a self-paced 2-mile treadmill run time-trial.
Read the detailed description
Participants will undergo baseline measurements of pulmonary function and maximal oxygen uptake (VO2max). They will then complete two familiarization trials, with 10 minutes of submaximal exercise (~40%VO2max) followed by a self-paced 2-mile treadmill time trial. Lastly, they will complete three experimental trials, repeating the same submaximal and time-trial exercise procedures while breathing the test gas (0%, 2%, or 4% CO2-all with normal 21% oxygen). During the experimental trials, arterialized capillary blood samples will be collected at rest breathing room air, at rest breathing the test gas, and during submaximal exercise at 40% VO2max breathing the test gas. The primary outcome is 2-mile treadmill time-trial performance. Secondary outcomes include ventilation, metabolic rate, heart rate, arterialized capillary pH/PCO2/HCO3, perceived exertion, dyspnea, leg discomfort, breathing descriptors, and headache ratings.
- Conditions
- Hypercapnia
- Being tested
- Inspired gas
- Medical subject headings
- Hypercapnia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Inspired gasOther
Inspired gas content
| Study group | Role | What they receive |
|---|---|---|
| 4% CO2 | Experimental | Inspired gas containing 4% CO2, 21% O2, balance N2 Receives: Other: Inspired gas |
| 2% CO2 | Experimental | Inspired gas containing 2% CO2, 21% O2, balance N2 Receives: Other: Inspired gas |
| 0% CO2 | Sham comparator | Inspired gas containing 0% CO2, 21% O2, balance N2 Receives: Other: Inspired gas |
What is being measured
The primary outcome is the main question the study is designed to answer.
2 mile self-paced treadmill time trial performance
Time to complete self-paced 2 mile treadmill time trial (min:sec)
Measured: 30 minutes
Secondary outcomes (11)
Ventilation rate
Ventilation rate will be assessed using a pneumotachometer [L/min]
Measured: 30 minutes
Oxygen consumption
Oxygen consumption will be assessed using computerized indirect calorimetry [ml/kg/min]
Measured: 30 minutes
Heart rate
Heart rate will be assessed using telemetry [beats per min]
Measured: 30 minutes
Arterialized capillary pH
Arterialized capillary pH will be assessed using a blood gas analyzer [Unitless]
Measured: 30 minutes
Arterialized capillary pCO2
Arterialized capillary pCO2 will be assessed using a blood gas analyzer [mmHg]
Measured: 30 minutes
Arterialized capillary HCO3
Arterialized capillary HCO3 will be assessed using a blood gas analyzer [mEq/L]
Measured: 30 minutes
Rating of perceived exertion
Rating of perceived exertion will be assessed using Borg's 6-20 scale [AU]
Measured: 30 minutes
Dyspnea
Rating of perceived dyspnea will be assessed using Borg's 0-10 scale [AU]
Measured: 30 minutes
Leg discomfort
Rating of perceived leg discomfort will be assessed using Borg's 0-10 scale [AU]
Measured: 30 minutes
Headache
Headache will be assessed using a visual analog scale [AU]
Measured: 30 minutes
Breathing descriptors
Breathing descriptors will be assessed by having participants check statements that apply to their breathing (e.g., breathing out requires more effort) [unitless]
Measured: 30 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Nov 2021
- Study start10 Sep 2021
- Primary completion14 Apr 2022
- Study completion14 Apr 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypercapniaStudies 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
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Randomized, single-blinded crossover design
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- United States Army Research Institute of Environmental Medicine
- Sponsor type
- US federal agency
- Responsible party
- Sponsor
- Investigators
- Benjamin J Ryan, Ph.D., Principal investigator, United States Army Research Institute of Environmental Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05116397
- Sponsor's protocol ID
- USARIEM
- Status last verified
- May 2022
- First submitted
- 13 Oct 2021
- Last updated
- 31 May 2022
- 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 31 May 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Influence of Graded Hypercapnia on Endurance Exercise Performance
- ClinicalTrials.gov ID
- NCT05116397
- Acronym / sponsor ID
- USARIEM
- Conditions
- Hypercapnia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- United States Army Research Institute of Environmental MedicineUS federal agency
- Study start
- 10 Sep 2021 (actual)
- Primary completion
- 14 Apr 2022 (actual)
- Study completion
- 14 Apr 2022 (actual)
- First posted
- 11 Nov 2021 (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.
The aim of this randomized, single-blind, placebo-controlled crossover trial is to determine the effects of graded hypercapnia (0, 2, and 4% inspired CO2) on endurance performance. Twelve healthy and fit young adults (men and women) will complete this study. Participants will perform experimental trials on 3 separate days (one each breathing 0%, 2%, and 4% inspired CO2-all with normal 21% oxygen). During each trial, they will perform 10 minutes of submaximal treadmill walking exercise and then complete a self-paced 2-mile treadmill run time-trial.
Detailed description
Participants will undergo baseline measurements of pulmonary function and maximal oxygen uptake (VO2max). They will then complete two familiarization trials, with 10 minutes of submaximal exercise (~40%VO2max) followed by a self-paced 2-mile treadmill time trial. Lastly, they will complete three experimental trials, repeating the same submaximal and time-trial exercise procedures while breathing the test gas (0%, 2%, or 4% CO2-all with normal 21% oxygen). During the experimental trials, arterialized capillary blood samples will be collected at rest breathing room air, at rest breathing the test gas, and during submaximal exercise at 40% VO2max breathing the test gas. The primary outcome is 2-mile treadmill time-trial performance. Secondary outcomes include ventilation, metabolic rate, heart rate, arterialized capillary pH/PCO2/HCO3, perceived exertion, dyspnea, leg discomfort, breathing descriptors, and headache ratings.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 3
- Model description
- Randomized, single-blinded crossover design
| Arm | Type | Receives |
|---|---|---|
| 4% CO2 | Experimental | Other: Inspired gasInspired gas containing 4% CO2, 21% O2, balance N2 |
| 2% CO2 | Experimental | Other: Inspired gasInspired gas containing 2% CO2, 21% O2, balance N2 |
| 0% CO2 | Sham comparator | Other: Inspired gasInspired gas containing 0% CO2, 21% O2, balance N2 |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (9 listed)
- Male or female, age 18-45
- In good health as determined by medical screening
- Passed his/her most recent Army Combat Fitness Test (ACFT) (Military Volunteers Only) or performs aerobic exercise at least 2 times per week and able to complete two mile run in ≤ 21 minutes (Civilian Volunteers)
- Willing to not participate in any exercise or drink alcoholic beverages for 24 hours before each study visit.
- Willing to not take part in any strenuous exercise in the 36 hours before each visit.
Key exclusion criteria (12 listed)
- Females who are pregnant or planning to become pregnant during the study
- Taking dietary supplements, prescriptions, or over the counter medication, other than a contraceptive (unless approved by medical staff \& PI)
- Musculoskeletal injuries that compromise ability to run on a treadmill
- Abnormal blood count, presence of abnormal blood chemicals (hemoglobin S or sickle cell traits)
- Smokers or tobacco/nicotine users (unless have quit > 1 month prior)
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 |
|---|---|---|
| Inspired gasInspired gas content | Other | 0% CO2, 2% CO2, 4% CO2 |
Primary outcome
2 mile self-paced treadmill time trial performance
Time frame: 30 minutes
Time to complete self-paced 2 mile treadmill time trial (min:sec)
11 secondary outcomes
Ventilation rate
Time frame: 30 minutes
Oxygen consumption
Time frame: 30 minutes
Heart rate
Time frame: 30 minutes
Arterialized capillary pH
Time frame: 30 minutes
Arterialized capillary pCO2
Time frame: 30 minutes
Arterialized capillary HCO3
Time frame: 30 minutes
Rating of perceived exertion
Time frame: 30 minutes
Dyspnea
Time frame: 30 minutes
Leg discomfort
Time frame: 30 minutes
Headache
Time frame: 30 minutes
Breathing descriptors
Time frame: 30 minutes
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 31 May 2022.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Benjamin J Ryan, Ph.D. principal investigator
United States Army Research Institute of Environmental Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Inspired gas in people with Hypercapnia, 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 9 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: finished, as of the sponsor's last update on 31 May 2022. 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. Some participants in this study may receive a placebo. 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?
2 mile self-paced treadmill time trial performance (time frame: 30 minutes). 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 31 May 2022.