Swimming exercise transiently decrease lung diffusing capacity in elite swimmers.

Area of Science:

• Pulmonary Physiology
• Sports Medicine
• Exercise Science

Background:

• Swimmers often exhibit enhanced lung function compared to other athletes.
• The impact of swimming exercise on lung diffusing properties remains under investigation.
• This study addresses the modifications in pulmonary alveolar-capillary diffusion post-swimming exercise.

Purpose of the Study:

• To evaluate changes in pulmonary alveolar-capillary diffusion in elite swimmers.
• To determine the effects of swimming training on lung diffusing capacity.
• To assess the physiological implications of these changes.

Main Methods:

• 21 elite swimmers (7 female, 14 male) with high training volumes (45-70 km/week) participated.
• Lung diffusing capacity for carbon monoxide (DLCO) and transfer coefficient (KCO) were measured using the single-breath method.
• Measurements were taken before and after 10 training sessions over 4 weeks, with 207 pre- to post-evaluations.

Main Results:

• A consistent decrease in lung diffusion capacity was observed during the follow-up period.
• DLCO decreased from 44.4±8.1 to 43.3±8.9 mL·min-1·mmHg-1 (P=0.047).
• KCO decreased from 5.92±0.79 to 5.70±0.81 mL·min-1·mmHg-1·L-1 (P=0.003).

Conclusions:

• Elite swimmers experience a subclinical impairment in lung diffusing capacity after swimming exercise.
• The observed reduction in DLCO and KCO suggests a temporary stress on the lungs.
• Despite the reduction, the swimming-induced stress did not lead to physiological dysfunction.