RESUMEN
Pulmonary Function Tests (PFT) of 45 swimmers who swam a distance of 2 to 5 kms per day regularly were compared with age, sex, height and weight matched controls. VC, IRV, FVC, FEV1 and V25 were higher in swimmers (S) than controls (NS) by 20%, 25%, 37.4%, 30.1% and 15.1% respectively. The effect of the period of training on PFT's was also analysed. Inspiratory capacity was significantly higher in Gr IS than NS probably due to a reduction in FRC, FVC and FEV1 were higher in Gr. II than NS. Greater differences were seen between Gr. IV S and NS, where FVC, FEV1, V75 and PEFR were higher by 50.2%, 38.2%, 69.4% and 25% respectively in the S than NS. Probably the first parameter to increase is IC. The greater differences in PFT values of Gr. IV S and NS may be due to hypertrophy of the diaphragm which requires hard work for prolong period. Further longitudinal studies are needed to confirm these observations.