Respiratory Function and Athletic Performance in Professional Soccer Players

Association Between Respiratory Function and Athletic Performance Parameters in Professional Soccer Players: A Cross-Sectional Study

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.

Professional soccer players from Istanbulspor A.S. Football Club will be screened and enrolled based on strict eligibility criteria. Eligible athletes will undergo a comprehensive, single-session testing protocol designed to prevent fatigue-related bias. Testing will commence with a baseline pulmonary function assessment and respiratory muscle strength evaluation (maximal inspiratory pressure [MIP] and maximal expiratory pressure [MEP]). Following a standardized rest interval, dynamic balance will be quantified using the Y-Balance Test (YBT). Subsequently, reactive visuomotor reaction times will be measured using the wireless BlazePod LED system. Finally, participants will execute higher-intensity, sport-specific performance assessments, including the isometric plank test for core endurance, a 60-second timed sit-up test for abdominal muscular endurance, and the T-drill test for agility. A standardized 10-minute seated rest interval will be strictly enforced between all physical assessments to ensure full physiological recovery. Bivariate correlation models will be utilized to analyze the direct relationships between respiratory indicators and performance indices.

Inclusion Criteria:

• 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.

Exclusion Criteria:

• 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.