An observational study in Athletic Performance, sponsored by Halic University. Not yet recruiting at 1 site in Turkey (Türkiye). Open to male participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-31.
Sponsored by Halic University · Observational
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.
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.
Halic University is the lead sponsor of 85 studies on the registry; 14 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Jiu-Jitsu Anaerobic Performance Test Total Valid Repetitions
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.
Time frame: At Visit 2 or Visit 3, within 6 days after Visit 1
Maximal Inspiratory Pressure
The highest acceptable maximal inspiratory pressure meeting prespecified reproducibility criteria, recorded in centimeters of water (cmH2O). Higher values indicate greater inspiratory muscle strength.
Time frame: At Visit 1
Maximal Expiratory Pressure
The highest acceptable maximal expiratory pressure meeting prespecified reproducibility criteria, recorded in centimeters of water (cmH2O). Higher values indicate greater expiratory muscle strength.
Time frame: At Visit 1
Maximum Static Kimono Grip Test Time
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.
Time frame: At Visit 2 or Visit 3, within 6 days after Visit 1
Forced Vital Capacity (FVC)
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.
Time frame: At Visit 1
Forced Expiratory Volume in 1 Second (FEV1)
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.
Time frame: At Visit 1
FEV1/FVC Ratio
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.
Time frame: At Visit 1
Peak Expiratory Flow (PEF)
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.
Time frame: At Visit 1
Plan to share: Undecided
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Start is estimated for Oct 2026; primary completion for Apr 2027, 6 months later.
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