SwimmingNCT07595328
Warm-up of the Inspiratory Musculature and Its Impact in Swimming Performance
A study testing POWERbreath in people with Swimming and IMT, run by Universidad Rey Juan Carlos.
Trial summary
Objective To evaluate the acute effect of four inspiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure [MIP]) on 100 m freestyle performance, and to analyze their impact on heart rate, blood lactate concentration, perceived exertion, and dyspnea in trained swimmers. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- What is being tested?
- POWERbreath
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 52 participants
- Where
- No sites listed yet
- Study dates
- Sep 2026to Jan 2027
- 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 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Participants of both sexes, aged over 18 years.
- Minimum swimming training frequency of at least two sessions per week, with a minimum duration of 30 minutes per session, consistently maintained over the last three months.
Who cannot join
- Current or previous diagnosis of respiratory diseases.
- Musculoskeletal injuries limiting the ability to perform a 100-meter swimming test.
- Participation in inspiratory muscle training programs within the last six months.
About this study
Official title: Warm-up of the Inspiratory Musculature and Its Impact on Physiological Parameters and Swimming Performance: Exploration of Intensities Based on Maximal Inspiratory Pressure
Objective To evaluate the acute effect of four inspiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure [MIP]) on 100 m freestyle performance, and to analyze their impact on heart rate, blood lactate concentration, perceived exertion, and dyspnea in trained swimmers.
Methods A randomized, crossover, double-blind experimental study was conducted. Participants were swimmers aged ≥18 years, with no respiratory or musculoskeletal pathology.
Read more
Each participant completed, in sessions separated by at least three days, an inspiratory muscle warm-up consisting of 30 breaths against resistive loads set at 15%, 40%, 60%, and 80% of their MIP, previously determined using standardized procedures.
Following each intervention, participants performed a maximal 100 m freestyle test. The following variables were recorded:
Swimming time Heart rate (during and post-exercise) Post-exercise capillary blood lactate concentration Rating of perceived exertion (Borg scale) Dyspnea (Dyspnea-12)
Conclusions This study will help identify the optimal inspiratory warm-up intensity to enhance swimming performance.
Read the detailed description
Inspiratory warm-up
An intervention performed prior to exercise consisting of breathing against resistance to activate the inspiratory muscles (mainly the diaphragm and accessory respiratory muscles) with the aim of enhancing their performance during subsequent effort.
Maximal Inspiratory Pressure (MIP)
The maximum pressure that an individual can generate during a forceful inspiration against an occluded airway. It is an indicator of inspiratory muscle strength and is used to prescribe training intensity.
Relative intensities (15%, 40%, 60%, 80% of MIP)
Percentages of MIP representing different levels of respiratory workload. They allow graded inspiratory resistance to investigate dose-response effects on performance.
Inspiratory Muscle Training (IMT)
A specific training method targeting the inspiratory muscles through controlled resistive breathing loads, aimed at improving strength, endurance, and ventilatory efficiency.
Crossover design
An experimental design in which each participant completes all experimental conditions, acting as their own control, thereby reducing inter-subject variability.
Double-blind design
A methodological approach in which neither participants nor evaluators are aware of the assigned condition, minimizing bias in performance and outcome assessment.
Swimming performance
A functional outcome measured primarily through time to complete a fixed distance, in this case 100 meters freestyle.
Cardiovascular response
The physiological response of the cardiovascular system to exercise, typically assessed through heart rate and post-exercise recovery dynamics.
Blood lactate concentration
A marker of metabolic stress during high-intensity exercise, reflecting the contribution of anaerobic glycolysis to energy production.
Perceived exertion
A subjective assessment of exercise intensity, commonly measured using standardized scales such as the Borg scale.
Respiratory discomfort (dyspnea)
A subjective sensation of breathing difficulty associated with exertion, reflecting ventilatory demand and exercise tolerance.
- Being tested
- POWERbreath
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
POWERbreathDevice
It is a crossover study in which the different exercise intensities are investigated.
| Study group | Role | What they receive |
|---|---|---|
| IMT: 15% | Experimental | The study will apply four respiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure) to compare their acute effects on these variables. This graded loading approach will allow identification of the optimal dose capable of maximizing diaphragmatic neuromuscular activation without inducing early fatigue, leveraging the post-activation potentiation phenomenon to improve respiratory efficiency and swimming performance. Receives: Device: POWERbreath |
| IMT:40% | Experimental | The study will apply four respiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure) to compare their acute effects on these variables. This graded loading approach will allow identification of the optimal dose capable of maximizing diaphragmatic neuromuscular activation without inducing early fatigue, leveraging the post-activation potentiation phenomenon to improve respiratory efficiency and swimming performance. Receives: Device: POWERbreath |
| IMT: 60% | Experimental | The study will apply four respiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure) to compare their acute effects on these variables. This graded loading approach will allow identification of the optimal dose capable of maximizing diaphragmatic neuromuscular activation without inducing early fatigue, leveraging the post-activation potentiation phenomenon to improve respiratory efficiency and swimming performance. Receives: Device: POWERbreath |
| IMT: 80% | Experimental | The study will apply four respiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure) to compare their acute effects on these variables. This graded loading approach will allow identification of the optimal dose capable of maximizing diaphragmatic neuromuscular activation without inducing early fatigue, leveraging the post-activation potentiation phenomenon to improve respiratory efficiency and swimming performance. Receives: Device: POWERbreath |
What is being measured
The primary outcome is the main question the study is designed to answer.
swimming time (100 meters)
After the respiratory interventions, participants will perform a maximal 100-meter freestyle swimming test under supervision. The total time will be recorded using a digital stopwatch, starting with the starting signal and ending when the swimmer touches the wall upon completing the distance.
Measured: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Secondary outcomes (8)
Maximal Inspiratory Pressure and Maximal Expiratory Pressure
Maximal Inspiratory Pressure (PIM/MIP) and Maximal Expiratory Pressure (PEM/MEP) are indicators of global respiratory muscle strength. PIM reflects the maximal negative pressure generated during a forced inspiratory effort against an occluded airway, mainly assessing diaphragmatic and external intercostal muscle function, whereas PEM reflects the maximal positive pressure produced during a forced expiratory effort, mainly involving abdominal and internal intercostal muscles. Both variables are expressed in centimeters of water (cmH₂O) and are widely used to quantify inspiratory and expiratory muscle performance, as well as to evaluate respiratory muscle fatigue and training adaptations in clinical and sports settings.
Measured: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Lactate
Immediately after the test, blood lactate will be measured using a Lactate Pro 2 portable analyzer, from a capillary blood sample obtained from the fingertip.
Measured: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Perceived exertion.
Perceived exertion will be assessed using the Borg scale (6-20), previously explained to ensure proper understanding, and will be recorded immediately after exercise through a direct interview.
Measured: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Dysnea
The Dyspnea-12 (D-12) scale is a multidimensional questionnaire used to assess the severity and qualitative perception of dyspnea (breathlessness). It evaluates both the physical and emotional components associated with breathing discomfort.
The questionnaire consists of 12 items:
My breath does not go in all the way My breathing requires more work I feel short of breath I have difficulty catching my breath I cannot get enough air My breathing is uncomfortable My breathing is exhausting My breathing makes me feel depressed My breathing makes me feel miserable My breathing is distressing My breathing makes me agitated My breathing is irritating
Each item is scored using a 4-point Likert scale:
0 = None
- = Mild
- = Moderate
- = Severe
Therefore, the total score ranges from 0 to 36 points.
Interpretation:
A low score indicates little or no perceived dyspnea. A moderate score reflects clinically relevant breathing discomfort. A high score indicates severe dyspnea with an important
Measured: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Heart rate.
Heart rate will be continuously monitored during the test and for up to five minutes post-exercise using a Polar H10 chest strap, placed on the anterior thoracic region just below the xiphoid process. The device will be calibrated before each session, and data will be analyzed using Polar Flow software to obtain parameters such as mean heart rate, maximum heart rate, which are key indicators of autonomic and cardiovascular response to exercise.
Measured: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Recovery time
Recovery time will be defined as the period required for heart rate to decrease following the cessation of exercise. This parameter reflects autonomic nervous system recovery, particularly parasympathetic reactivation after physical exertion. Heart rate recovery will be analyzed during the first five minutes post-exercise using data collected from the Polar H10 device. Faster recovery times are generally associated with better cardiovascular fitness and autonomic regulation, whereas delayed recovery may indicate increased physiological stress or fatigue.
Measured: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Heart rate variability
Heart rate variability (HRV) refers to the variation in the time intervals between consecutive heartbeats (R-R intervals). HRV is considered a non-invasive marker of autonomic nervous system activity and reflects the balance between sympathetic and parasympathetic modulation. HRV data obtained from the Polar H10 sensor will be analyzed using Polar Flow software, and parameters such as RMSSD and SDNN may be extracted. Higher HRV values are typically associated with better autonomic adaptability and recovery capacity, while lower values may reflect fatigue, stress, or reduced physiological adaptability.
Measured: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Forced Vital Capacity and Forced Expiratory Volume in 1 second
Forced Vital Capacity (FVC/CVF) and Forced Expiratory Volume in 1 second (FEV₁) are spirometric measures used to assess ventilatory capacity and pulmonary function. FVC represents the total volume of air that can be forcibly exhaled after a maximal inspiration, expressed in liters (L), while FEV₁ represents the volume exhaled during the first second of that maneuver, also expressed in liters. The FEV₁/FVC ratio is commonly used to identify ventilatory limitations, particularly obstructive patterns. Together, these variables provide key information on airway function, expiratory flow limitation, and overall pulmonary performance.
Measured: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 May 2026
- Study startSep 2026 (estimated)
- Primary completionJan 2027 (estimated)
- Study completionJan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SwimmingStudies 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
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 52 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universidad Rey Juan Carlos
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Agustin Velazquez Córdoba, Universidad Rey Juan Carlos
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07595328
- Sponsor's protocol ID
- 100220261562026
- Other IDs
- Sponsor-Investigator
- Status last verified
- Feb 2026
- First submitted
- 19 Apr 2026
- Last updated
- 19 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: At present, no definitive decision has been made regarding the sharing of individual participant data. On the one hand, making anonymized data available could enhance scientific transparency, reproducibility of results, and the development of new research lines based on the collected data. However, several relevant aspects are also considered, such as the protection of participant confidentiality, strict compliance with applicable data protection regulations (GDPR), and the need to ensure appropriate and controlled use of the information. Additionally, the potential limitations related to sample size and the specific context of the study are taken into account. If data sharing is ultimately implemented, it would be provided exclusively in anonymized format, upon justified request, following appropriate project evaluation and, where applicable, through formal data use agreements.
Study at a glance
From the registry record, last updated by the sponsor on 19 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Warm-up of the Inspiratory Musculature and Its Impact on Physiological Parameters and Swimming Performance: Exploration of Intensities Based on Maximal Inspiratory Pressure
- ClinicalTrials.gov ID
- NCT07595328
- Acronym / sponsor ID
- 100220261562026
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 52 participants (estimated)
- Lead sponsor
- Universidad Rey Juan CarlosUniversity, hospital or other
- Study start
- Sep 2026 (estimated)
- Primary completion
- Jan 2027 (estimated)
- Study completion
- Jan 2027 (estimated)
- First posted
- 19 May 2026 (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.
Objective To evaluate the acute effect of four inspiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure [MIP]) on 100 m freestyle performance, and to analyze their impact on heart rate, blood lactate concentration, perceived exertion, and dyspnea in trained swimmers.
Methods A randomized, crossover, double-blind experimental study was conducted. Participants were swimmers aged ≥18 years, with no respiratory or musculoskeletal pathology.
Each participant completed, in sessions separated by at least three days, an inspiratory muscle warm-up consisting of 30 breaths against resistive loads set at 15%, 40%, 60%, and 80% of their MIP, previously determined using standardized procedures.
Following each intervention, participants performed a maximal 100 m freestyle test. The following variables were recorded:
Swimming time Heart rate (during and post-exercise) Post-exercise capillary blood lactate concentration Rating of perceived exertion (Borg scale) Dyspnea (Dyspnea-12)
Conclusions This study will help identify the optimal inspiratory warm-up intensity to enhance swimming performance.
Detailed description
Inspiratory warm-up
An intervention performed prior to exercise consisting of breathing against resistance to activate the inspiratory muscles (mainly the diaphragm and accessory respiratory muscles) with the aim of enhancing their performance during subsequent effort.
Maximal Inspiratory Pressure (MIP)
The maximum pressure that an individual can generate during a forceful inspiration against an occluded airway. It is an indicator of inspiratory muscle strength and is used to prescribe training intensity.
Relative intensities (15%, 40%, 60%, 80% of MIP)
Percentages of MIP representing different levels of respiratory workload. They allow graded inspiratory resistance to investigate dose-response effects on performance.
Inspiratory Muscle Training (IMT)
A specific training method targeting the inspiratory muscles through controlled resistive breathing loads, aimed at improving strength, endurance, and ventilatory efficiency.
Crossover design
An experimental design in which each participant completes all experimental conditions, acting as their own control, thereby reducing inter-subject variability.
Double-blind design
A methodological approach in which neither participants nor evaluators are aware of the assigned condition, minimizing bias in performance and outcome assessment.
Swimming performance
A functional outcome measured primarily through time to complete a fixed distance, in this case 100 meters freestyle.
Cardiovascular response
The physiological response of the cardiovascular system to exercise, typically assessed through heart rate and post-exercise recovery dynamics.
Blood lactate concentration
A marker of metabolic stress during high-intensity exercise, reflecting the contribution of anaerobic glycolysis to energy production.
Perceived exertion
A subjective assessment of exercise intensity, commonly measured using standardized scales such as the Borg scale.
Respiratory discomfort (dyspnea)
A subjective sensation of breathing difficulty associated with exertion, reflecting ventilatory demand and exercise tolerance.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| IMT: 15% | Experimental | Device: POWERbreathThe study will apply four respiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure) to compare their acute effects on these variables. This graded loading approach will allow identification of the optimal dose capable of maximizing diaphragmatic neuromuscular activation without inducing early fatigue, leveraging the post-activation potentiation phenomenon to improve respiratory efficiency and swimming performance. |
| IMT:40% | Experimental | Device: POWERbreathThe study will apply four respiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure) to compare their acute effects on these variables. This graded loading approach will allow identification of the optimal dose capable of maximizing diaphragmatic neuromuscular activation without inducing early fatigue, leveraging the post-activation potentiation phenomenon to improve respiratory efficiency and swimming performance. |
| IMT: 60% | Experimental | Device: POWERbreathThe study will apply four respiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure) to compare their acute effects on these variables. This graded loading approach will allow identification of the optimal dose capable of maximizing diaphragmatic neuromuscular activation without inducing early fatigue, leveraging the post-activation potentiation phenomenon to improve respiratory efficiency and swimming performance. |
| IMT: 80% | Experimental | Device: POWERbreathThe study will apply four respiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure) to compare their acute effects on these variables. This graded loading approach will allow identification of the optimal dose capable of maximizing diaphragmatic neuromuscular activation without inducing early fatigue, leveraging the post-activation potentiation phenomenon to improve respiratory efficiency and swimming performance. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Participants of both sexes, aged over 18 years.
- Minimum swimming training frequency of at least two sessions per week, with a minimum duration of 30 minutes per session, consistently maintained over the last three months.
Key exclusion criteria (3 listed)
- Current or previous diagnosis of respiratory diseases.
- Musculoskeletal injuries limiting the ability to perform a 100-meter swimming test.
- Participation in inspiratory muscle training programs within the last six months.
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 |
|---|---|---|
| POWERbreathIt is a crossover study in which the different exercise intensities are investigated. | Device | IMT: 15%, IMT: 60%, IMT: 80%, IMT:40% |
Primary outcome
swimming time (100 meters)
Time frame: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
After the respiratory interventions, participants will perform a maximal 100-meter freestyle swimming test under supervision. The total time will be recorded using a digital stopwatch, starting with the starting signal and ending when the swimmer touches the wall upon completing the distance.
8 secondary outcomes
Maximal Inspiratory Pressure and Maximal Expiratory Pressure
Time frame: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Lactate
Time frame: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Perceived exertion.
Time frame: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Dysnea
Time frame: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Heart rate.
Time frame: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Recovery time
Time frame: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Heart rate variability
Time frame: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
Forced Vital Capacity and Forced Expiratory Volume in 1 second
Time frame: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.
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 19 May 2026.
- Individual participant dataSharing planned: Undecided. At present, no definitive decision has been made regarding the sharing of individual participant data. On the one hand, making anonymized data available could enhance scientific transparency, reproducibility of results, and the development of new research lines based on the collected data. However, several relevant aspects are also considered, such as the protection of participant confidentiality, strict compliance with applicable data protection regulations (GDPR), and the need to ensure appropriate and controlled use of the information. Additionally, the potential limitations related to sample size and the specific context of the study are taken into account. If data sharing is ultimately implemented, it would be provided exclusively in anonymized format, upon justified request, following appropriate project evaluation and, where applicable, through formal data use agreements.
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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.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A study testing POWERbreath in people with Swimming and IMT, run by Universidad Rey Juan Carlos.
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 2 inclusion and 3 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: opening soon, as of the sponsor's last update on 19 May 2026. Status can change between updates, so confirm with the study contact before making plans.
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?
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?
swimming time (100 meters) (time frame: This measurement will be carried out from the randomization process until 8 weeks after the start of the inspiratory training program.). 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 19 May 2026.