POVEZANOST SNAGE DIŠNE MUSKULATURE S KARDIOVASKULARNIM I METABOLIČKIM ISHODIMA KARDIOPULMONALNOG TESTA OPTEREĆENJA

Objectives: According to prior knowledge, there are limited insights about the role of respiratory muscle strength and endurance on athletes’ performance during the anaerobic part of metabolism until maximal exertion. The aim of this study was to examine the association between the strength/endurance of inspiratory muscles and ventilatory and metabolic parameters measured from anaerobic threshold up to the maximum load during the cardiopulmonary exercise test (CPET) on a treadmill in a group of healthy professional athletes. Study design: The study used a cross-sectional association design for strength and endurance of inspiratory muscles with the CPET ventilatory and metabolic parameters determined on the checkup day together with the anthropometric measurements and hematology, biochemistry and urine analyses. Subjects and methods: Seventy highly trained healthy professional athletes of team sports (basketball and handball) aged 16 – 36 years were recruited. The study was conducted in a clinical CPET laboratory and included detailed clinical examination, anthropometric measurements, urine and blood analyses (hematology and biochemistry), inspiratory muscle strength and endurance testing, spirometry, electrocardiogram and CPET. Ventilatory and metabolic parameters at second ventilatory threshold (VT2), at maximal effort, and their differences were tested for association with inspiratory muscle strength (PImax) and endurance (Tlim) measures. Tlim was for this study measured as the time to maintain inspiration at or above 80 % of PImax. Results: The difference in end-tidal oxygen tension (ΔPETO2) between VT2 and maximal effort was significantly and independently associated with resting heart rate (HR), resting systolic blood pressure (BP), PImax and lean body mass (LBM) (r2 = 0,26, p = 0,016; multivariate regression analysis). The difference in exhaled carbon dioxide (ΔVCO2) between VT2 and maximal effort was significantly and independently associated with body mass index (BMI), resting HR, resting systolic BP, and PImax (r2 = 0,25, p = 0,022; multivariate regression analysis). Conclusion: We found in our group of professional athletes that it is the inspiratory muscle strength (with some other variables) and not endurance that significantly affects the performance of these athletes in the part of most exclusively anaerobic metabolism and that it should be tested and trained systematically.