LUNG FUNCTION

One important measure of cardiopulmonary fitness is functional exercise capacity. A popular and standardized method for evaluating this ability is the Six-Minute Walk Test (6MWT), which measures how various physiological systems react to submaximal effort. While its impact on cardiovascular parameters is well-documented, the specific, acute effects of a self-paced functional exercise like the 6MWT on spirometric lung function levels in healthy individuals remain less characterized. Establishing this baseline response is crucial for the accurate interpretation of tests in clinical populations. This study sought to evaluate the acute effect of the Six-Minute Walk Test (6MWT) on lung function levels in healthy adult male subjects. A pre- post intervention study design was employed. A cohort of healthy adult male students from the University of Benin, aged 18-29 years, was recruited. Forced Vital Capacity (FVC), Forced Expiratory Volume in One Second (FEV1), FEV1/FVC ratio, and Peak Expiratory Flow (PEF) were measured using baseline spirometry. Each participant then completed the 6MWT on a standardized 30-meter track in compliance with the American Thoracic Society's (ATS) recommendations. Spirometry was repeated immediately post-exercise to capture acute changes in lung function parameters. Results showed a significant post-exercise reduction in FEV1 and the FEV1/FVC ratio. In contrast, no significant changes were observed in FEF25, FEF75, or PEF. The significant decrease in FEV1 and FEV1/FVC suggests mild, exercise-induced bronchoconstriction predominantly in the large, central airways. The stability of small airway parameters (FEF25, FEF75) and PEF indicates this response is localized, not affecting peripheral airway function or maximal expiratory effort. This pattern aligns with known physiological responses to exercise, where increased ventilation can trigger airway reactivity. The 6MWT induces an acute, measurable reduction in large airway function in healthy males. This finding establishes that a degree of airway reactivity is a normal physiological response to submaximal exercise. Recognizing this baseline is essential for accurately differentiating normal post- exercise dynamics from pathological bronchoconstriction in clinical assessments.