Normobaric HypoxiaNCT06253039
"Living Low - Training High" Methods and Physiological Responses in Well-trained Swimmers
A study testing Repeated sprint in people with Normobaric Hypoxia and Hypoventilation, run by Faculdade de Motricidade Humana at 1 site in Portugal.
Trial summary
To overcome the lack of knowledge regarding the impact of different "living low, training high" methods on swimming performance, a 4-week intervention will be carried out to determine and compare the effects of three Repeated Sprints in Hypoxia (RSH) methods with each other and with a control group. Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Normobaric Hypoxia, Hypoventilation, Normoxia
- What is being tested?
- Repeated sprint
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- 1 sitePortugal
- Study dates
- 10 Feb 2024to 30 Mar 2026
- 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 30 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Swimmers from both sexes;
- With regular participation in National Championships;
- More than five years of training experience;
- No recent exposure/acclimatization to altitude;
- No recent exposition to Blood Flow Restriction training.
Who cannot join
- athletes who had an acclimatization experience or exposure to altitude lasting more than 10 days in the last 6 months;
- pregnant or postpartum women;
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effects of Innovative "Living Low - Training High" Methods on Performance and Physiological Responses in Well-trained Swimmers.
To overcome the lack of knowledge regarding the impact of different "living low, training high" methods on swimming performance, a 4-week intervention will be carried out to determine and compare the effects of three Repeated Sprints in Hypoxia (RSH) methods with each other and with a control group. Our goal is to characterize and compare the adaptations in swimming performance and in cardiorespiratory, metabolic, and muscle oxygenation responses that can arise after a 4-week training period of RSH and RSN performed in a ski-ergometer.
Read the detailed description
Recently, several new "living low training high" (LLTH) methods involving repeated sprints in hypoxia have shown promising results, especially in team sports. However, the underlying mechanisms remain mostly unclear, as does its effectiveness in improving swimming performance.
Hypoxemia can be induced by exposure to ambient hypoxia conditions, by voluntary hypoventilation at low lung volume, or by vascular occlusion (namely, blood flow restriction). Swimming performance is influenced by aerobic and anaerobic metabolism and could benefit from these different LLTH methods.
This project aims to compare the effects of repeated sprint training performed with a ski-ergometer 1) in a hypoxic chamber; 2) in normoxia 3) in control group on the performance of swimmers, as well as to characterize cardiorespiratory, metabolic, and muscle oxygenation adaptations that may contribute to the improvements achieved after four weeks of each of these types of training.
All groups will be evaluated before and after the supervised training period in three testing sessions in normoxia, separated by at least 24 hours within 7 days. Swimmers will perform: 1) time-trial (100 m front crawl) in the swimming pool to determine performance, V̇̇O2 peak, and lactate concentration following the test; 2) incremental test to exhaustion in the swim-ergometer to determine aerobic peak power, cardiorespiratory responses (V̇̇O2max, ventilatory thresholds), and maximal tissue deoxygenation; 3) time-trial test in the ski-ergometer (100 m) to access performance, muscle and pulmonary oxygen uptake kinetics, and the relative contribution of energetic systems.
Training sessions will be performed in the ski-ergometer and consist of 3 sets of 5x10s all-out sprints with 20s and 5 min of passive rest between the sprints and sets, respectively. In all testing and training sessions, pulse oxygen saturation will be measured for safety purposes.
- Conditions
- Normobaric Hypoxia, Hypoventilation, Normoxia
- Being tested
- Repeated sprint
- Keywords
- Repeated sprint methods, Swimming performance, Training programs, V̇̇O2peak, Lactate concentration, Energetic systems, Oxygen uptake kinetics, Deoxygenation kinetics
- Medical subject headings
- Hypoventilation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Repeated sprintOther
- The group will endure four weeks (8 sessions) of the assigned training program in addition to the regular swimming training.
- Data collection sessions: All groups will be evaluated before and after the supervised training period in three testing sessions in normoxia separated by at least 24 hours within 7 days.
- Training sessions: will be performed in the ski ergometer and consist of 3 sets of 5x10s all-out sprints with 20s and 5 min of passive rest between the sprints and sets, respectively.
| Study group | Role | What they receive |
|---|---|---|
| Normobaric hypoxia (RSH) | Experimental | The RSH group will perform training sessions in a normobaric hypoxic chamber at a simulated altitude of 3000 meters (FiO2 14.5%) Receives: Other: Repeated sprint |
| Control Group | No intervention | Participants did not receive any additional intervention and continued their usual swimming training throughout the study period. |
| Normoxia (RSN) | Experimental | The control group will perform the training sessions in normoxia (FIO2, 20.9%) Receives: Other: Repeated sprint |
What is being measured
The primary outcome is the main question the study is designed to answer.
Ventilatory thresholds and maximum oxygen consumption
mL/kg·min
Measured: Before and after 4 weeks of supervised training period
Lactate concentration
mmol.L-1
Measured: Before and after 4 weeks of supervised training period
Muscle oximetry
Near-infrared spectroscopy (NIRS)
Measured: Before and after 4 weeks of supervised training period
Time-trial
seconds
Measured: Before and after 4 weeks of supervised training period
Secondary outcomes (2)
Heart rate
bpm
Measured: Before and after 4 weeks of supervised training period
Arterial oxygen saturation
Oxymetry (%)
Measured: Before and after 4 weeks of supervised training period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Feb 2024
- Study start10 Feb 2024
- Primary completion15 Apr 2025
- Study completion30 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Normobaric HypoxiaStudies 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
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 32 participants (actual)
Sponsor and investigators
- Lead sponsor
- Faculdade de Motricidade Humana
- Sponsor type
- University, hospital or other
- Collaborators
- Centro de Alto Rendimento do Jamor
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06253039
- Sponsor's protocol ID
- RSH swimmers
- Status last verified
- Feb 2024
- First submitted
- 21 Dec 2023
- Last updated
- 9 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 9 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Innovative "Living Low - Training High" Methods on Performance and Physiological Responses in Well-trained Swimmers.
- ClinicalTrials.gov ID
- NCT06253039
- Acronym / sponsor ID
- RSH swimmers
- Conditions
- Normobaric Hypoxia, Hypoventilation, Normoxia
- Keywords
- Repeated sprint methods, Swimming performance, Training programs, V̇̇O2peak, Lactate concentration, Energetic systems, Oxygen uptake kinetics, Deoxygenation kinetics
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 32 participants (actual)
- Lead sponsor
- Faculdade de Motricidade HumanaUniversity, hospital or other
- Collaborators
- Centro de Alto Rendimento do Jamor
- Study start
- 10 Feb 2024 (actual)
- Primary completion
- 15 Apr 2025 (actual)
- Study completion
- 30 Mar 2026 (actual)
- First posted
- 12 Feb 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 overcome the lack of knowledge regarding the impact of different "living low, training high" methods on swimming performance, a 4-week intervention will be carried out to determine and compare the effects of three Repeated Sprints in Hypoxia (RSH) methods with each other and with a control group. Our goal is to characterize and compare the adaptations in swimming performance and in cardiorespiratory, metabolic, and muscle oxygenation responses that can arise after a 4-week training period of RSH and RSN performed in a ski-ergometer.
Detailed description
Recently, several new "living low training high" (LLTH) methods involving repeated sprints in hypoxia have shown promising results, especially in team sports. However, the underlying mechanisms remain mostly unclear, as does its effectiveness in improving swimming performance.
Hypoxemia can be induced by exposure to ambient hypoxia conditions, by voluntary hypoventilation at low lung volume, or by vascular occlusion (namely, blood flow restriction). Swimming performance is influenced by aerobic and anaerobic metabolism and could benefit from these different LLTH methods.
This project aims to compare the effects of repeated sprint training performed with a ski-ergometer 1) in a hypoxic chamber; 2) in normoxia 3) in control group on the performance of swimmers, as well as to characterize cardiorespiratory, metabolic, and muscle oxygenation adaptations that may contribute to the improvements achieved after four weeks of each of these types of training.
All groups will be evaluated before and after the supervised training period in three testing sessions in normoxia, separated by at least 24 hours within 7 days. Swimmers will perform: 1) time-trial (100 m front crawl) in the swimming pool to determine performance, V̇̇O2 peak, and lactate concentration following the test; 2) incremental test to exhaustion in the swim-ergometer to determine aerobic peak power, cardiorespiratory responses (V̇̇O2max, ventilatory thresholds), and maximal tissue deoxygenation; 3) time-trial test in the ski-ergometer (100 m) to access performance, muscle and pulmonary oxygen uptake kinetics, and the relative contribution of energetic systems.
Training sessions will be performed in the ski-ergometer and consist of 3 sets of 5x10s all-out sprints with 20s and 5 min of passive rest between the sprints and sets, respectively. In all testing and training sessions, pulse oxygen saturation will be measured for safety purposes.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Normobaric hypoxia (RSH) | Experimental | Other: Repeated sprintThe RSH group will perform training sessions in a normobaric hypoxic chamber at a simulated altitude of 3000 meters (FiO2 14.5%) |
| Control Group | No intervention | –Participants did not receive any additional intervention and continued their usual swimming training throughout the study period. |
| Normoxia (RSN) | Experimental | Other: Repeated sprintThe control group will perform the training sessions in normoxia (FIO2, 20.9%) |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Swimmers from both sexes;
- With regular participation in National Championships;
- More than five years of training experience;
- No recent exposure/acclimatization to altitude;
- No recent exposition to Blood Flow Restriction training.
Key exclusion criteria (2 listed)
- athletes who had an acclimatization experience or exposure to altitude lasting more than 10 days in the last 6 months;
- pregnant or postpartum women;
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 |
|---|---|---|
| Repeated sprint* The group will endure four weeks (8 sessions) of the assigned training program in addition to the regular swimming training. * Data collection sessions: All groups will be evaluated before and after the supervised training period in three testing sessions in normoxia separated by at least 24 hours within 7 days. * Training sessions: will be performed in the ski ergometer and consist of 3 sets of 5x10s all-out sprints with 20s and 5 min of passive rest between the sprints and sets, respectively. | Other | Normobaric hypoxia (RSH), Normoxia (RSN) |
Primary outcome
Ventilatory thresholds and maximum oxygen consumption
Time frame: Before and after 4 weeks of supervised training period
mL/kg·min
Lactate concentration
Time frame: Before and after 4 weeks of supervised training period
mmol.L-1
Muscle oximetry
Time frame: Before and after 4 weeks of supervised training period
Near-infrared spectroscopy (NIRS)
Time-trial
Time frame: Before and after 4 weeks of supervised training period
seconds
2 secondary outcomes
Heart rate
Time frame: Before and after 4 weeks of supervised training period
Arterial oxygen saturation
Time frame: Before and after 4 weeks of supervised training period
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 9 Oct 2026.
- 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.
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 Repeated sprint in people with Normobaric Hypoxia and Hypoventilation, run by Faculdade de Motricidade Humana at 1 site in Portugal.
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 5 inclusion and 2 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 9 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 1 site in Portugal. 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?
Ventilatory thresholds and maximum oxygen consumption (time frame: Before and after 4 weeks of supervised training period). The study lists 4 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 9 Oct 2026.