INTRODUCTION: Experimental models are used for simulation of situations related to physical training. OBJECTIVE: This study had the objective of verifying the fitness of rats in training; this was achieved through the measurement of the concentration of lactic acid in the blood serum. METHODOLOGY: An experimental study using 40 Wistar male adult rats, divided into five groups of eight individuals and a control group was carried out. The first test of Maximum Effort (TE) was applied after one week of familiarization with the treadmill running and right before the first day of training. The following effort tests were applied at every ten days. In order to measure the concentration of lactic acid in the blood after the test; it 1ml of blood was collected from each rat. The Student t test was used to compare the means. RESULTS: Lactic acid serum significantly decreased in groups GE10, 20, 30 between the first and the last effort test. In the G30 there was a significant difference between the initial and final tests regarding speed (p = 0.003) and time (p = 0.018), as well as in the G40 group, where the initial velocity was (p = 0.0006) and time (p = 0.0001). CONCLUSION: The results measured through the lactic acid in the blood showed that rats submitted to physical training present better metabolic capacity and that with suitable training, the physical fitness increased after the physical effort. This effort is well tolerated by the rats up to 40 days of treadmill running.
rat; exercise; lactic acid
