Respiratory Muscle Strength and Jiu-Jitsu-Specific Performance in Male Brazilian Jiu-Jitsu Athletes

August 26, 2026 updated by: Halic University

Relationship of Maximal Inspiratory and Expiratory Pressures With Jiu-Jitsu-Specific Anaerobic Performance and Static Kimono Grip Endurance in Male Brazilian Jiu-Jitsu Athletes: A Cross-Sectional Study

Brazilian Jiu-Jitsu (BJJ) is an intermittent combat sport that requires repeated high-intensity efforts and sustained gripping. This analytical cross-sectional study will examine whether respiratory muscle strength is associated with BJJ-specific anaerobic performance and static kimono grip endurance in adult male BJJ athletes. Forty athletes will attend three assessment visits separated by 48 to 72 hours. Maximal inspiratory pressure, maximal expiratory pressure, and spirometric indices (forced vital capacity [FVC], forced expiratory volume in 1 second [FEV1], FEV1/FVC ratio, and peak expiratory flow [PEF]) will be measured at the first visit. The Jiu-Jitsu Anaerobic Performance Test and the Maximum Static Kimono Grip Test will be completed at the other two visits in randomized order. The primary analysis will examine the association between maximal inspiratory pressure and the total number of valid repetitions completed during the Jiu-Jitsu Anaerobic Performance Test. Spirometric indices will be evaluated as secondary outcomes.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

This is an analytical cross-sectional observational study involving 40 male Brazilian Jiu-Jitsu athletes aged 18 to 40 years. Assessments will be completed during three visits separated by 48 to 72 hours. At Visit 1, eligibility will be assessed and written informed consent will be obtained. Demographic and sport-related information, including self-reported height, body weight, and Brazilian Jiu-Jitsu experience, will be recorded. Spirometry will be performed using acceptable and repeatable forced expiratory maneuvers in accordance with current ATS/ERS technical standards. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC ratio, and peak expiratory flow (PEF) will be recorded; percent-predicted and z-score values will also be documented when available. Respiratory muscle strength will be assessed as maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP). Participants will perform at least five acceptable maneuvers for each pressure measurement, with up to eight attempts when necessary. The highest acceptable value meeting reproducibility criteria will be recorded in cmH2O. At Visits 2 and 3, participants will complete the Jiu-Jitsu Anaerobic Performance Test (JJAPT) and the Maximum Static Kimono Grip Test on separate days in randomized order. Before each performance test, participants will complete a standardized sport-specific warm-up. The JJAPT consists of five 60-second work bouts separated by 45 seconds of passive recovery. A partner whose body weight is within 5% of the participant's self-reported body weight will be used, and the total number of valid butterfly-guard lifting repetitions will be recorded. For the static kimono grip test, a kimono is wrapped around a horizontal bar and the participant maintains a suspended position with maximal elbow flexion for as long as possible; performance is recorded in seconds. The primary analysis will assess the relationship between MIP and JJAPT total valid repetitions. Secondary analyses will assess MEP in relation to JJAPT performance and MIP and MEP in relation to static kimono grip endurance. Spirometric indices will be summarized descriptively and examined in exploratory secondary analyses in relation to the performance outcomes. Self-reported body weight and Brazilian Jiu-Jitsu experience in months will be considered as prespecified covariates.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Turkey (Türkiye)
      • Istanbul, Turkey (Türkiye), 34337
        • Roger Gracie Academy Turkey
        • Contact:
        • Principal Investigator:
          • Muhammed Hüseyin Pekeren

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Adult male Brazilian Jiu-Jitsu athletes who train regularly at clubs or academies in Istanbul, Türkiye, and meet the prespecified eligibility criteria. Participants will be recruited by non-probability sampling.

Description

Inclusion Criteria:

  • Male sex
  • Age 18 to 40 years
  • At least 1 year of Brazilian Jiu-Jitsu experience
  • Brazilian Jiu-Jitsu training on at least 2 days per week during the previous 3 months
  • Familiarity with gi/kimono training and the butterfly-guard lifting movement
  • Ability to safely and technically perform the Maximum Static Kimono Grip Test and the Jiu-Jitsu Anaerobic Performance Test
  • Provision of written informed consent

Exclusion Criteria:

  • Diagnosed cardiovascular, respiratory, neurological, metabolic, or musculoskeletal condition that may affect maximal testing or participant safety
  • Active pain, acute injury, or relevant surgery during the previous 6 months
  • Current regular use of cigarettes, electronic cigarettes, or inhaled nicotine products
  • Medical advice to avoid maximal physical effort
  • Regular use of medication that may materially affect study measurements

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Male Brazilian Jiu-Jitsu Athletes
Adult male Brazilian Jiu-Jitsu athletes who train regularly and complete spirometric pulmonary function, respiratory muscle strength, BJJ-specific anaerobic performance, and static kimono grip endurance assessments. No intervention will be assigned.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Jiu-Jitsu Anaerobic Performance Test Total Valid Repetitions
Time Frame: At Visit 2 or Visit 3, within 6 days after Visit 1
Total number of valid butterfly-guard lifting repetitions completed across five 60-second work bouts separated by 45 seconds of passive recovery. Higher values indicate better BJJ-specific anaerobic performance.
At Visit 2 or Visit 3, within 6 days after Visit 1

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Maximal Inspiratory Pressure
Time Frame: At Visit 1
The highest acceptable maximal inspiratory pressure meeting prespecified reproducibility criteria, recorded in centimeters of water (cmH2O). Higher values indicate greater inspiratory muscle strength.
At Visit 1
Maximal Expiratory Pressure
Time Frame: At Visit 1
The highest acceptable maximal expiratory pressure meeting prespecified reproducibility criteria, recorded in centimeters of water (cmH2O). Higher values indicate greater expiratory muscle strength.
At Visit 1
Maximum Static Kimono Grip Test Time
Time Frame: At Visit 2 or Visit 3, within 6 days after Visit 1
Maximum time, in seconds, that the participant maintains a suspended position with maximal elbow flexion while gripping a kimono wrapped around a horizontal bar. Higher values indicate greater static kimono grip endurance.
At Visit 2 or Visit 3, within 6 days after Visit 1
Forced Vital Capacity (FVC)
Time Frame: At Visit 1
Forced vital capacity measured by spirometry and recorded in liters (L). Percent-predicted and z-score values will also be documented when available. Higher values generally indicate greater ventilatory volume, with interpretation based on appropriate reference limits.
At Visit 1
Forced Expiratory Volume in 1 Second (FEV1)
Time Frame: At Visit 1
Forced expiratory volume in the first second measured by spirometry and recorded in liters (L). Percent-predicted and z-score values will also be documented when available. Higher values generally indicate greater expiratory volume in the first second, interpreted using appropriate reference limits.
At Visit 1
FEV1/FVC Ratio
Time Frame: At Visit 1
Ratio of forced expiratory volume in the first second to forced vital capacity, calculated from acceptable spirometry maneuvers and recorded as a ratio and percentage. The z-score and lower limit of normal will be documented when available; lower values may indicate airflow limitation.
At Visit 1
Peak Expiratory Flow (PEF)
Time Frame: At Visit 1
Peak expiratory flow obtained during acceptable forced spirometry maneuvers and recorded in liters per second (L/s). The highest acceptable value will be recorded. Higher values indicate greater maximal expiratory flow.
At Visit 1

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Halic University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 25, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 26, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 31, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 31, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 26, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • HALICU-BJJ-2209-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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