This study analyzed the possibility of using movement velocity and the perceived exertion as predictors of relative load in the parallel squat exercise. In order to determine the full load-velocity and load-perceived exertion relationships, 290 young, resistance-trained athletes (209 male and 81 female) performed a progressive strength test up to the one-repetition maximum. Longitudinal regression models were used to predict the relative load from the average velocity and the OMNI-RES 0-10 scale, considering sets as the time-related variable. Two adjusted predictive equations were developed from the association between the relative load and the average velocity or the perceived exertion expressed after performing several sets of 1 to 3 repetitions during the progressive test. The resulting two models were capable of estimating the relative load with an accuracy of 79% and 86% for the average velocity [Relative load (% 1RM) = 120.15 – 83.54 (AV)] and the exertion [Relative load (% 1RM) = 5.07 + 9.63 (RPE)] respectively. The strong association between relative load with average velocity and the perceived exertion support the use of both predictive variables to estimate strength performance in parallel squat
