Diet, lung function and swimmers' performance

Purpose: The aim of this study was to correlate athletic performance with both lung function and diet. Design: Open, uncontrolled trial. Materials and Methods: Sixty-eight swimmers (28 females and 40 males), 9-15 years old, were registered for the study. The average age was 11.75 years, the average height was 151.65 cm and the average weight was 42.88 kg. Every swimmer completed a questionnaire which included details about eating habits and performances in the 100 m freestyle and backstroke. They were submitted to spirometry tests and diffusion capacity measurements (with a simple inspiration of carbon monoxide). All swimmers had three spirometry tests. The best one was recorded and compared to the expected values. Results: The average diffusing capacity was 29.07% higher than expected and the average forced expiratory volume in the first second was 4.21% higher than expected. Swimmers who consumed 5.7 meals per week based on meat and 4.43 meals per week based on vegetables performed better than swimmers who consumed 4 meals per week based on vegetables and 3.35 meals per week based on meat (p < 0.001). Swimmers with better lung function performed significantly more impressively in both styles (p < 0.001). Based on multiple logistic regression analysis we found equations that correlate swimming performance with age, height, lung function and diet. Conclusions: Swimmers' performance is related to lung function and diet. Diffusing capacity and dynamic volume measurement are adequate methods of evaluating lung function