Validity of Different Velocity-Based Methods and Repetitions-to-Failure Equations for Predicting the 1 Repetition...

Pérez-Castilla, A, Suzovic, D, Domanovic, A, Fernandes, JFT, and García-Ramos, A. Validity of different velocity-based methods and repetitions-to-failure equations for predicting the 1 repetition maximum during 2 upper-body pulling exercises. J Strength Cond Res 35(7): 1800-1808, 2021-This study aimed to compare the accuracy of different velocity-based methods and repetitions-to-failure equations for predicting the 1 repetition maximum (i.e., maximum load that can be lifted once; 1RM) during 2 upper-body pulling exercises. Twenty-three healthy subjects (twelve men and eleven women) were tested in 2 sessions during the lat pull-down and seated cable row exercises. Each session consisted of an incremental loading test until reaching the 1RM followed by a set of repetitions-to-failure against the 80% 1RM load. The 1RM was estimated from the individual load-velocity relationships modeled through 4 (∼40, 55, 70, and 85% 1RM; multiple-point method) or 2 loads (∼40 and 85% 1RM; 2-point method). Mean velocity was recorded with a linear position transducer and a Smartphone application. Therefore, 4 velocity-based methods were used as a result of combining the 2 devices and the 2 methods. Two repetitions-to-failure equations (Mayhew and Wathen) were also used to predict the 1RM from the load and number of repetitions completed. The absolute differences with respect to the actual 1RM were higher for the repetitions-to-failure equations than velocity-based methods during the seated cable row exercise (p = 0.004), but not for the lat pull-down exercise (p = 0.200). The repetitions-to-failure equations significantly underestimated the actual 1RM (p < 0.05; range: -6.65 to -2.14 kg), whereas no systematic differences were observed for the velocity-based methods (range: -1.75 to 1.65 kg). All predicted 1RMs were highly correlated with the actual 1RM (r ≥ 0.96). The velocity-based methods provide a more accurate estimate of the 1RM than the Mayhew and Wathen repetitions-to-failure equations during the lat pull-down and seated cable row exercises.