Alterações no equilíbrio acido-básico e lactacidemia em corredores masculinos de ultramaratona de montanha durante uma prova de 45 km

Abstract

The present study aimed to analyze changes in acid-base balance and lactacidemia in male mountain ultramarathon runners during a 45 km race. The parameters of 40 runners with a mean age of 38.3 ± 6.9 years were analyzed. Blood analyzes were performed using the GEM Premier 3000 Gasometry equipment, and the following parameters were evaluated: pH, HCO3-, pCO2, pO2 and Lac-. To compare the changes in the acid-base balance and lactacidemia pre-test and post-test, the paired samples t test was performed, adopting the significance level of p˂0.05. The analysis showed values for Lac- in the pre-test condition of 1.95±0.62 mmol/L and post-test 2.73±0.89 mmol/L. The analysis of gases, the pH results in the pre-test condition for the post-test showed values of 7.42±0.02 and 7.42±0.03 (p=0.723). The HCO3- pre-test was 26.47±1.64 mmol/L and for the post-test of 21.81±2.42 mmol/L, the pre-test pCO2 was 40.77±2.55 mm/Hg and post-test -test of 33.65±2.78 mm/Hg (p˂0.0001) and pre-test pO2 65.45±4.30 mm/Hg and the post-test 65.82±6.30 mm/Hg (p=0.747). The performance of prolonged exercise during the practice ultramarathon races triggers numerous changes in the body. In this study, the data showed a progressive decrease in pCO2, causing a progressive increase in hypocapnic alkalosis caused by hyperventilation and by the increased use of substrates in fat oxidation. Lactate was below the blood lactate accumulation point, indicating that the metabolite was used as a source of energy by the skeletal muscles during the test.