Efeito de consumo de carboidrato e de exercício físico sobre a concentração de glicogênio

Abstract

-Carbohydrate is an important source of energy which is stored as glycogen. Since this storage may be related to the use of sports drinks, this study evaluated the changes in liver, skeletal muscle and kidney glycogen content of rats supplemented with maltodextrin and submitted to aerobic exercise at maximum lactate steady state or highintensity anaerobic exercise. Sixty-nine male Wistar rats, 60 days old at the beginning of the experiment, were used. The training protocol consisted of 8 weeks of continuous aerobic (60 min/day) or intermittent swimming (two periods of 30 min/day at an interval of 10 min and an exercise/rest ratio of 15 seconds), with overloads corresponding to 5% and 10% of body weight, respectively. The animals were supplemented for 37 days with a daily dose of 0.48 g/kg maltodextrin dissolved in water or received pure water. Factorial ANOVA or the Kruskal-Wallis test was used for data analysis. Aerobic training resulted in a significant increase in blood glucose (p˂0.02) and in a decline in hepatic glycogen content (p<0.02), while anaerobic exercise promoted a significant increase in lactate concentration (p<0.001) and a decrease in skeletal muscle (p=0.02) and kidney (p<0.03) glycogen content. Maltodextrin supplementation significantly increased muscle (p=0.008) and kidney (p<0.02) glycogen content in rats submitted to aerobic exercise. Eight weeks of aerobic and anaerobic exercise caused changes in liver, skeletal muscle and kidney glycogen content, as well as in blood glucose and blood lactate. Maltodextrin supplementation was effective in increasing skeletal muscle and kidney glycogen stores in rats submitted to aerobic exercise.