Impactos de uma estratégia de jejum intermitente associada a treinamento de endurance na composição corporal e desempenho físico de ratos wistar

Abstract

The use of weight loss strategies and control of body composition is widely used in high performance sports where weight control is paramount for good athletic performance. In addition, the prevention and treatment of chronic diseases and their risk factors are always recommended by increasing the level of physical activity and food control. Among the food control practices, has been increasing the use of intermittent fasting. However, little is known about the effects of intermittent fasting in practicing physical activities and athletes. The objective of this study was to evaluate the effect of endurance training associated with the practice of intermittent fasting on metabolic aspects of physical performance, body composition and redox balance of adult Wistar rats. For this, we used 26 rats divided into 4 groups: Intermittent Fasting (JI) N = 7, Intermittent Fasting + Exercise (JI + EX) N = 7 Exercise(EX) N = 6 and control(CON) n = 6. The animals were subjected to six weeks of swimming training during fasting 18 hours daily. After the trial period the JI+EX group rats had higher performance in progressive load test in relation to JI and CON groups without changes in the lactate point of fatigue. As adaptation to training during JI, there was also an increase in citrate synthase activity in the JI+EX group in relation to EX and CON groups. It was also found an increase in intramuscular fat accumulation in the JI+EX group compared to the EX group and the JI group. The animals JI+EX had lower lean body mass by comparing them with the EX and CON animals but without changes in food consumption. In assessing feed efficiency, the JI and JI+EX groups had lower feed efficiency compared to the groups that not performed JI. By assessing body composition, the JI group had a lower percentage of protein content and increased lipid in relation to JI+EX groups and EX; It was also found greater relative mass of Brown Adipose Tissue (BAT) animal JI and JI+EX both in relation to CON as the EX group. In the analyzes related to hepatic metabolism, an increase in HDL cholesterols found in JI+EX group: in the parameters related to oxidative activity, the JI group had increased lipid peroxidation and protein carbonylation compared to control, while the groups that performed exercise had a lower protein carbonyls than the CON animals. Thus, it was observed that when performing endurance exercise plus JI, the animals had the highest gain of physical performance that seems to have been the result of metabolic adaptations that allowed greater use of energy when needed, such as greater availability of HDL cholesterol and lipids largest stocks in skeletal muscle. Also it could be seen that the JI proved to be a metabolically harmful strategy, given the large redox imbalance found in the liver of animals undergoing strategy. However, we also note the beneficial effects found in combining this strategy with endurance exercise in the fasting period.