HypoxiaNCT06901284
Graded Exercise Hypoxia Testing
An observational study of Hypoxia, run by Mayo Clinic at 2 sites in United States.
Trial summary
The purpose of this study is to develop a single, standardized test to determine how individuals tolerate acute hypoxia in a stepwise fashion. We aim to evaluate the association between multiple factors, such as ventilatory compensation, heart rate response, acid-base changes, sex, pulmonary function, etc, which may… Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Hypoxia
- What is being tested?
- Graded Exercise Test and Graded Hypoxia Exercise Test
- How many people
- 30 participants
- Where
- 2 sitesUnited States
- Study dates
- 15 Apr 2025to 11 Sep 2025
- Phase
- Observational
- 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 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: A total of 50 participants (25 female, 25 male) will be recruited for this study. Participants will be recruited from the general population.
Who may be able to join
- Physically active (≥150 minutes of moderate physical activity per week)
Who cannot join
- Contraindications to exercise testing
- Currently pregnant
- Musculoskeletal or metabolic disease
- Allergies to lidocaine
- Body-mass index ≤18 or ≥35 kg·m-2
- Pacemaker
- No confounding cardiorespiratory disease
- Persistent tobacco use (>15 pack years)
Trial locations and contacts
2 sites in 1 country.
United States2 sites
Mayo Clinic
Rochester, Minnesota, 55902
St. Mary's Hospital
Rochester, Minnesota, 55902
About this study
The purpose of this study is to develop a single, standardized test to determine how individuals tolerate acute hypoxia in a stepwise fashion. We aim to evaluate the association between multiple factors, such as ventilatory compensation, heart rate response, acid-base changes, sex, pulmonary function, etc, which may explain why some individuals tolerate exercise in hypoxia better than others. Identifying these factors of association will inform future pharmacological and non-pharmacological attempts to combat acute hypoxic exercise.
- Conditions
- Hypoxia
- Being tested
- Graded Exercise Test, Graded Hypoxia Exercise Test
- Medical subject headings
- Hypoxia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Graded Exercise TestDiagnostic test
Participants will perform a graded exercise test on either a cycle ergometer or treadmill. The testing protocol will begin with a 5- 10 min warm-up of either cycling or running/walking at the participants preferred pace.
If the graded exercise test is on a bike, exercise will begin at wattage that elicits ~50% of their heart rate max, HRmax = 208 - 0.7 × age and increase by either 10W, 15W, or 20W every two minutes in a stepwise fashion until symptom limitation. The step of the wattage increase will be at the discretion of the investigators.
If the graded exercise test is on a treadmill, the test will begin at a speed that elicits ~50% of predicted HRmax. Following, the speed of the treadmill will increase 0.5 mph (0.8 km/hr) every two minutes in a stepwise fashion until symptom limitation. If the participant maxes out the speed of the treadmill, we will increase the grade 2% every 2-minutes until symptom limitation.
Graded Hypoxia Exercise TestDiagnostic test
Participants will perform a single constant work rate exercise tests during graded hypoxia. They will be outfitted with either a facemask or mouthpiece connected to a uni-directional breathing valve. During inspiration, subjects will breathe from a closed-system Douglas bag balloon reservoir (~200 L) connected to the value on the inspired side via air-tight clean-bor tubing.
The participant will complete the same mode of exercise as they did during visit 1, either bike or treadmill. The resistance on the bike or incline of the treadmill will be set to elicit an intensity equivalent to ~50% of their V̇O2max determined during visit 1. Participants will complete 5-minute stages over a range of FiO2 values. The exercise test will begin in an FiO2=0.21 (i.e. room air). Following this first 5-min stage the FiO2 will increase to 0.25, afterwards, participants will complete another stage at FiO2=0.21 and then decrease in a stepwise fashion every 5-minutes.
| Study group | Role | What they receive |
|---|---|---|
| Study group | 50 participants (25 female, 25 male) who are physically active for at least 150 minutes per week, at a moderate activity level. Receives: Diagnostic Test: Graded Exercise Test; Diagnostic Test: Graded Hypoxia Exercise Test |
What is being measured
The primary outcome is the main question the study is designed to answer.
PaO₂/FiO₂ Ratio
The PaO₂/FiO₂ ratio is a widely used measure of oxygenation efficiency in the lungs. It compares the arterial oxygen partial pressure (PaO₂, measured in mmHg) to the fraction of inspired oxygen (FiO₂, expressed as a decimal). The ratio provides insight into the ability of the lungs to transfer oxygen into the bloodstream. A PaO₂/FiO₂ ratio of 300-400 is considered to be mild hypoxemia. Participants are considered as poorly tolerating hypoxia if their ratio is <400 and good at tolerating hypoxia if their ratio is >400.
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 posted28 Mar 2025
- Study start15 Apr 2025
- Primary completion30 Jul 2025
- Study completion11 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypoxiaStudies of the same condition, open and under way.
- More trials run by Mayo ClinicThe sponsor's other registered studies.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Mayo Clinic
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Michael J. Joyner, M.D., Mayo Clinic
- Investigators
- Michael Joyner, M.D., Principal investigator, Mayo Clinic
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06901284
- Sponsor's protocol ID
- 25-000497
- Status last verified
- Jan 2026
- First submitted
- 24 Mar 2025
- Last updated
- 14 Oct 2026
- 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 14 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Graded Exercise Hypoxia Testing
- ClinicalTrials.gov ID
- NCT06901284
- Acronym / sponsor ID
- 25-000497
- Conditions
- Hypoxia
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Mayo ClinicUniversity, hospital or other
- Study start
- 15 Apr 2025 (actual)
- Primary completion
- 30 Jul 2025 (actual)
- Study completion
- 11 Sep 2025 (actual)
- First posted
- 28 Mar 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.
The purpose of this study is to develop a single, standardized test to determine how individuals tolerate acute hypoxia in a stepwise fashion. We aim to evaluate the association between multiple factors, such as ventilatory compensation, heart rate response, acid-base changes, sex, pulmonary function, etc, which may explain why some individuals tolerate exercise in hypoxia better than others. Identifying these factors of association will inform future pharmacological and non-pharmacological attempts to combat acute hypoxic exercise.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Study group | – | Diagnostic Test: Graded Exercise Test, Diagnostic Test: Graded Hypoxia Exercise Test50 participants (25 female, 25 male) who are physically active for at least 150 minutes per week, at a moderate activity level. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- A total of 50 participants (25 female, 25 male) will be recruited for this study. Participants will be recruited from the general population.
Key inclusion criteria (1 listed)
- Physically active (≥150 minutes of moderate physical activity per week)
Key exclusion criteria (8 listed)
- Contraindications to exercise testing
- Currently pregnant
- Musculoskeletal or metabolic disease
- Allergies to lidocaine
- Body-mass index ≤18 or ≥35 kg·m-2
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 |
|---|---|---|
| Graded Exercise TestParticipants will perform a graded exercise test on either a cycle ergometer or treadmill. The testing protocol will begin with a 5- 10 min warm-up of either cycling or running/walking at the participants preferred pace. If the graded exercise test is on a bike, exercise will begin at wattage that elicits ~50% of their heart rate max, HRmax = 208 - 0.7 × age and increase by either 10W, 15W, or 20W every two minutes in a stepwise fashion until symptom limitation. The step of the wattage increase will be at the discretion of the investigators. If the graded exercise test is on a treadmill, the test will begin at a speed that elicits ~50% of predicted HRmax. Following, the speed of the treadmill will increase 0.5 mph (0.8 km/hr) every two minutes in a stepwise fashion until symptom limitation. If the participant maxes out the speed of the treadmill, we will increase the grade 2% every 2-minutes until symptom limitation. | Diagnostic test | Study group |
| Graded Hypoxia Exercise TestParticipants will perform a single constant work rate exercise tests during graded hypoxia. They will be outfitted with either a facemask or mouthpiece connected to a uni-directional breathing valve. During inspiration, subjects will breathe from a closed-system Douglas bag balloon reservoir (~200 L) connected to the value on the inspired side via air-tight clean-bor tubing. The participant will complete the same mode of exercise as they did during visit 1, either bike or treadmill. The resistance on the bike or incline of the treadmill will be set to elicit an intensity equivalent to ~50% of their V̇O2max determined during visit 1. Participants will complete 5-minute stages over a range of FiO2 values. The exercise test will begin in an FiO2=0.21 (i.e. room air). Following this first 5-min stage the FiO2 will increase to 0.25, afterwards, participants will complete another stage at FiO2=0.21 and then decrease in a stepwise fashion every 5-minutes. | Diagnostic test | Study group |
Primary outcome
PaO₂/FiO₂ Ratio
Time frame: 30 minutes
The PaO₂/FiO₂ ratio is a widely used measure of oxygenation efficiency in the lungs. It compares the arterial oxygen partial pressure (PaO₂, measured in mmHg) to the fraction of inspired oxygen (FiO₂, expressed as a decimal). The ratio provides insight into the ability of the lungs to transfer oxygen into the bloodstream. A PaO₂/FiO₂ ratio of 300-400 is considered to be mild hypoxemia. Participants are considered as poorly tolerating hypoxia if their ratio is <400 and good at tolerating hypoxia if their ratio is >400.
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 14 Oct 2026.
- Individual participant dataSharing planned: No
Related trials for Hypoxia
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Acute Hypoxic Respiratory Failure, Acute Respiratory Distress Syndrome (ARDS)
RecruitingObservational study
Comparison of Pulse Oximetry (SpO2) With Different Oximeters and Arterial Saturation (SaO2): Oxygap2 Study
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A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Efficacy of RLS-0071 in Newborns With Moderate or Severe Hypoxic-Ischemic Encephalopathy Undergoing Therapeutic Hypothermia
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RecruitingPhase 2
The PROTECT-HIE Pilot Trial
Hypoxic-ischemic Encephalopathy (HIE)
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.
Michael Joyner, M.D. principal investigator
Mayo Clinic
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Hypoxia, run by Mayo Clinic at 2 sites 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 1 inclusion and 8 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 14 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites 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?
PaO₂/FiO₂ Ratio (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 14 Oct 2026.