Respiratory Function and Athletic Performance in Professional Soccer Players

NCT07617116 | Not Yet Recruiting

• 1 other identifier: 22
• Study Type: observational
• Target: 31
• Locations: 0 countries
• Sites: N/A

Brief Summary

This prospective observational study aims to investigate the relationship between respiratory function and multidimensional athletic performance parameters in professional soccer players. The primary hypothesis of the study is that soccer players with enhanced respiratory function and superior respiratory muscle strength will exhibit optimized motor performance outcomes and shorter (faster) reactive reaction times. Investigators will evaluate respiratory muscle strength, spirometric pulmonary functions, dynamic balance, core and abdominal endurance, and reactive visuomotor reaction times during a single testing session within the competitive season.

Conditions

Respiratory Function; Respiratory Muscle Strength; Athletic Performance; Reaction Time

Outcome Measures

Primary Outcomes (5)

• Maximal Expiratory Pressure (MEP)

  Description: Respiratory muscle strength will be assessed using a portable digital respiratory pressure meter. Participants will execute a maximal expiratory maneuver from total lung capacity after full inspiration while wearing a nose clip. The highest reproducible value from at least three technically acceptable trials will be recorded in centimeters of water (cmH₂O).

  2 hours

• Maximal Inspiratory Pressure (MIP)

  Description: Respiratory muscle strength will be assessed using a portable digital respiratory pressure meter. Participants will perform a maximal inspiratory maneuver from residual volume following complete expiration while wearing a nose clip. The highest reproducible value from at least three technically acceptable trials will be recorded in centimeters of water (cmH₂O).

  2 hour

• Reactive Visuomotor Reaction Time

  Cognitive-motor reaction speed will be quantified using a wireless LED pod system arrayed in an equidistant semi-circular matrix. Participants will utilize their dominant lower limb to deactivate randomly illuminated pods as quickly as possible across 10 sets of 22 randomized stimuli. The mean reaction time across the challenge will be recorded in milliseconds (ms).

  2 hours

• Dynamic Postural Stability (Y-Balance Test)

  Functional reach capacity and dynamic balance will be quantified using a standardized Y-Balance Test apparatus. While maintaining a single-leg stance, participants will push indicator blocks in the anterior, posteromedial, and posterolateral directions. The maximum reach distance from three successful trials for each direction will be normalized to leg length and used to calculate a comprehensive Composite Score percentage (%) for both limbs.

  2 hours

• Static Core Stabilization Endurance (Prone Plank Test)

  Isometric core endurance will be quantified using the isometric prone plank test on a high-density mat. Participants will support their body weight exclusively on their forearms and toes, maintaining a strict neutral horizontal alignment of the head, spine, hips, and ankles. The test will be terminated when the participant voluntarily discontinues or fails to maintain correct alignment. Total duration will be recorded in seconds (sec).

  2 hours

Secondary Outcomes (5)

• Forced Vital Capacity (FVC)

  2 hours

• Forced Expiratory Volume in 1 Second (FEV1%)

  2 hours

• Peak Expiratory Flow (PEF)

  2 hours

• Dynamic Abdominal Endurance (60-Second Sit-Up Test)

  2 hours

• Change-of-Direction Speed and Agility (T-Drill Test)

  2 hours

Interventions

Respiratory and Athletic Performance Assessments OTHER

Participants will not receive any experimental clinical intervention as part of this observational study. Instead, they will undergo standard, non-invasive physiological and athletic performance screenings during their competitive season. These assessments will include digital respiratory pressure manometry to evaluate maximal inspiratory and expiratory pressures, computerized spirometry to measure pulmonary functions, the Y-Balance Test for dynamic postural stability, the BlazePod wireless LED system for reactive visuomotor reaction times, and sport-specific field tests (isometric plank, 60-second sit-up, and T-drill agility tests) to evaluate core endurance and agility. All measurements will be completed during a single testing session following standardized recovery intervals.

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

The study population will consist of elite-level athletic professionals, specifically young adult male professional soccer players. Participants will be recruited from a licensed professional football club actively competing in national league training and competition schedules.

You may qualify if:

• Participants will be actively competing, licensed professional soccer players. -Participants will be engaged in regular, team-based training and competitive match schedules.
• Participants will voluntarily provide written informed consent before any study-related physical performance assessments are conducted.

You may not qualify if:

• Participants will be excluded if they present with an acute upper or lower respiratory tract infection that could potentially affect pulmonary function or maximal respiratory muscle performance.
• Participants will be excluded if they have a documented history of major cardiothoracic surgery.
• Participants will be excluded if they have any diagnosed respiratory and/or cardiovascular disorder associated with dyspnea or impaired pulmonary mechanics.
• Participants will be excluded if they present with any condition that elevates clinical risk during maximal inspiratory and expiratory pressure assessments.
• Participants will be excluded if they have sustained an acute musculoskeletal injury within the preceding 6 weeks that could compromise maximal physical exertion during sport-specific performance testing.

Sponsors & Collaborators

• Istinye University: lead

MeSH Terms

Conditions

Respiratory Aspiration

Interventions

Respiratory Rate

Condition Hierarchy (Ancestors)

Respiration Disorders; Respiratory Tract Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Vital Signs; Physical Examination; Diagnostic Techniques and Procedures; Diagnosis; Respiration; Respiratory Physiological Phenomena; Circulatory and Respiratory Physiological Phenomena

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Dr. Assistant Professor

Study Record Dates

• First Submitted: May 23, 2026
• First Posted: June 1, 2026
• Study Start: May 25, 2026
• Primary Completion (Estimated): July 5, 2026
• Study Completion (Estimated): July 10, 2026
• Last Updated: June 1, 2026

Record last verified: 2026-05