Immediate Spirometric Response to Submaximal Exercise in Healthy Young Adult Males

Background: Acute exercise produces immediate changes in respiratory mechanics and airflow, but the pattern of spirometric response after a single bout of submaximal exercise is not uniform across studies. This study evaluated the immediate effect of a single bout of submaximal exercise on spirometric parameters in healthy young adult males. Methodology: This prospective pre-post interventional study was conducted in the department of physiology over two years. A total of 200 healthy young adult males aged 18-30 years were included. Participants with a history of smoking, respiratory or cardiovascular disease, bronchial asthma, allergy, recent acute illness, alcoholism, athletic training, or musculoskeletal limitation were excluded. Baseline anthropometry was recorded. Spirometry was performed before exercise using a standard technique, with a minimum of three acceptable maneuvers obtained for each participant. Participants then underwent a single bout of submaximal exercise using the Harvard Step Test with a 16-inch step at a cadence of 40 steps per minute for six minutes. Spirometry was repeated immediately after exercise. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow rate (PEFR), and FEV1/FVC ratio were analyzed. Pre- and post-exercise values were compared using the Wilcoxon signed-rank test; p < 0.05 was considered statistically significant. Results: The mean age of the participants was 22.12 ± 3.72 years. The mean FVC decreased significantly from 3.77 ± 0.82 L to 3.54 ± 0.74 L (p = 0.001). The mean FEV1 increased significantly from 3.26 ± 0.54 L to 3.41 ± 0.63 L (p = 0.020). PEFR also increased significantly from 7.26 ± 2.28 to 9.36 ± 1.70 (p < 0.001). The FEV1/FVC ratio changed from 0.84 ± 0.08 to 0.85 ± 0.08, which was not statistically significant (p = 0.337). Conclusions: A single bout of submaximal exercise produced significant immediate changes in spirometric parameters in healthy young adult males. Expiratory flow indices improved after exercise, while FVC decreased, and the FEV1/FVC ratio remained stable.