Efeitos do treinamento aeróbio em parâmetros imunológicos e metabólicos basais e induzidos por exercício físico agudo em humanos

Abstract

Introduction: The acute physical exercise promotes the release of cytokines in the circulation. Our hypothesis is that aerobic training alters this response. Thus, the purpose of this study was to evaluate the effects of six weeks of aerobic training on rest and induced expression (after acute exercise) of cytokines, adipokines, BDNF. We also evaluatedcirculating leukocytes at rest before and after training Methods: Twenty one men, non-participants of any aerobic training were divided intotwo groups: control group (GC; n=8) (25.1±0.9years; 70.1±3.5kg; 1.79±0.02m; 45.2±1.5mL.kg-1.min-1) and training group (GT; n=13) (22.5±0.7years; 72.9±1.9kg; 1.76±0.02m; 44.9±1.3mL.kg-1.min-1). All tests were performed on a cycle ergometer. The volunteers performed a progressive test to evaluate the maximal oxygen uptake (VO2MAX),two to five constant tests to identify the maximal lactate steady state (MLSS). After determination of MLSS(1), all subjects performed an exercise until fatigue (acute exercise) at this intensity. Afterwards they were submitted to six weeks of aerobic training, three times aweek at the MLSS(1) intensity. Next, the same tests were performed to determine the new MLSS(2) value and the volunteers executed two acute exercises, being one under this new MLSS value (relative MLSS, 2) and another using the pre-training value (absolute MLSS, 1). In the training group during the acute exercises, blood samples were collected for plasma cytokines determination by using Sandwich ELISA method. Before and after training were determined circulating leukocytes by flow citometry. Results: The acute exercise led to increased concentrations of circulating IL-6, sTNFR1, CXCL10/IP-10, leptin, resistin, and BDNF at the time of end of exercise and TNF- a, IL-10, sTNFR2 and adiponectin in the recovery period of exercise. The GT had an 11.2% increase in VO2MAX and 14.7% in the intensity of MLSS. The training did not alter themediators at baseline. Aerobic training has promoted smaller increase in IL-6, sTNFR2, leptin and BDNF and a faster reduction of sTNFR1 after exercise with the same absolute intensity of the pre-training. Since, TNF-, IL-10, CXCL10/IP-10, resistin and adiponectin are independent of fatigue to increase similarly to the pre-training. In addition, aerobic training resulted in smaller levels of sTNFR1 and BDNF at recovery period of acute exercise with the same relative intensity of the pre-training. Conclusions: Aerobic training was effective. The acute physical exercise on the intensity of MLSS was able to alter the circulating levels of cytokines, which agrees with the literature. The period of six weeks in young, healthy and physically active, was not able tochange the circulating concentrations in the rest of the mediators evaluated. There was training for IL-6, sTNFR1, sTNFR2, leptin and BDNF after acute physical exercise with the same absolute intensity of the pre-training. The sTNFR1 and BDNF were the only mediators evaluated that were influenced by the training of six weeks in the acutephysical exercise with relative effort similiar to the pre-training. Moreover, the training did not influenced the response of TNF-, IL-10, CXCL10/IP-10, resistin and adiponectin, soon the increases of these mediators occur even when fatigue was not reached. These differentresponses after aerobic training, suggest that there is a fine control in the production of these mediators during acute exercise and, possibly, these parameters are released in less effort in relation to acute pre-training, may have dominant physiological role.