O ponto de quebra do duplo produto como marcador mais sensível de estresse e a IL-12 como possível moduladora do rendimento de atletas

Abstract

Physical exercise, traditionally used by science to evaluate the performance of athletes, gains a new perspective with the emergence of sports science, which aims to reproduce the natural conditions of different sports for the study of immunometabolism. The present study sought the acute impact caused by a running test on a treadmill, on different biomarkers, changes in the cardiovascular system, and a possible correlation between IL-12 and performance in running athletes. This cross-sectional study uses a treadmill protocol with a gas analyzer for ten male athletes. The initial speed was 10 km/h with an increment of 1 km every 400 meters. The cardiovascular assessment was performed using an exercise electrocardiogram, blood pressure was measured using a sphygmomanometer and stethoscope, the metabolic assessment was performed using a computerized analyzer, and IL-12 concentration was measured using flow cytometry. Individualized systolic blood pressure showed a steady state in the initial and middle thirds and with changes in the final third of the test. Heart rate and the double product showed changes in the initial third of the test, revealing themselves as the most acutely affected cardiovascular components in this protocol. The heatmap showed a correlation of 1.0 (P=0.00278) between the variation in IL-12 concentration and VO2 in the time of respiratory compensation, of 0.943 (P=0.0167) between pre-exercise IL-12 and the time to reach the maximum effort, with the same correlation coefficient and P value between the pre-IL-12 and the distance covered, and between the pre-IL-12 and the test time. The post-exercise IL-12 correlated 0.9 (P=0.0167) with the heart rate at the respiratory compensation point. A breakpoint was observed, both for the double product and for the heart rate, between minutes 2 and 3 of the test, both measurements being more acute than the anaerobic threshold (7:52 minutes) and the respiratory compensation point (11:08 minutes) and even the breakpoint for systolic blood pressure (between minutes 12 and 15). The mean percentage change in heart rate and the double product had the same value (213%). IL-2 showed a variation of 160% between times. In treadmill running tests with incremental load, the heart rate breakpoint and the double product are the most sensitive and acute stress level markers. Although the production of IL-12 during exercise depends on the intensity and duration of the exercise, it may be correlated with the performance of athletes, bringing to light possible immunomodulation of the performance-metabolism-immune system triad.