Efeitos do treinamento intervalado de alta intensidade na biomecânica da corrida

Abstract

In recent years, the practice of running has grown in popularity, increasing the search for specialized advice and training. Among which we can highlight high-intensity interval training (HIIT), as it is considered an effective strategy for improving performance. One of the factors that can influence performance are the biomechanical variables of running, where we can highlight the frequency and length of strides, targets of several studies carried out on an asphalt track and on an ergometric treadmill. However, it is known that training performed on a treadmill can influence performance on the track in a way that is not understood. Therefore, this study evaluated the effects of a 4-week HIIT protocol, performed on a treadmill, on the performance of runners in a 2400-meter running test on an asphalt track. To carry out this study, 11 runners with at least 2 years of experience in street running and with results in 5k races of less than 21 minutes were selected, which characterizes them as welltrained runners. These athletes were submitted to an incremental test performed on a treadmill to determine the maximum aerobic speed (VAM), which served as the basis for establishing the training intensities. Speeds corresponding to 50%, 90%, 100% and 110% of MAS were defined for each runner. The athletes' performance was evaluated by means of the total reduction in the time to perform the track test, while the variables of frequency and stride length were measured using the Kinovea program. Differences in the values obtained before and after the training protocol were observed, where significant differences were found in the results. The length of strides observed in the performance of the track test was greater in the post-HIIT condition and the total time of performance of the test was shorter in this same condition. During the training protocol, significant differences were observed in the frequency of strides at the intensities of 100% and 110% of the MAS in relation to the intensity of 50% of the MAS. As for the stride length, there were significant differences in the intensities of 90%, 100% and 110% compared to the intensity of 50%, as well as a significant difference in the intensity of 90% in relation to the other intensities. In view of these results, we concluded that the HIIT protocol performed on a treadmill for a period of four weeks proved to be an efficient strategy to improve the performance of runners in the track test, evidenced by the increase in VO2max and the reduction of time to perform the exercise. test. This improvement is related to positive adjustments in running biomechanics observed through the increase in stride length during the test.