Lung capacity and alveolar gas diffusion in aquatic athletes: Implications for performance and health

Abstract

Background: The diffusion capacity of carbon monoxide (DLCO) provides a measure of gas transfer in the lungs. Endurance training does not increase lung volumes and diffusion in land-based athletes. However swimmers have larger lungs and better diffusion capacity than other matched athletes and controls. Purpose: The aim of this study is to evaluate pulmonary alveoli-capillary diffusion and lung volumes in elite aquatic athletes, specifically: swimmers, artistic swimmers and water polo players. Methods: The participants were 64 international level aquatic athletes including 31 swimmers (11 female and 20 male), 12 artistic swimmers (only female), and 21 water polo players (10 female and 11 male). The single-breath method was used to measure DLCO and pulmonary parameters. Results: The main finding of this study is that DLCO is high, in aquatic athletes, clearly above their reference values, both in females (33.4 ± 9.4 mL·min-1·mmHg-1; 135%) and males (48.0 ± 5.83 mL·min-1·mmHg-1; 148%). There was no different DLCO between groups in female swimmers, artistic swimmers and water polo players (34.7 ± 8.3 to 33.4 ± 4.0 to 32.1 ± 5.6 mL·min-1·mmHg-1), but male swimmers had higher DLCO compared to water polo players (50.4 ± 5.3 to 43.4 ± 7.0, p = 0.014). Conclusions: Aquatic athletes have larger lungs and better diffusion capacity than the percentage predicted by age and height. Therefore, swimming-based sports could be beneficial to improve the pulmonary function in many different segments of the population.