The impact of test loads on the accuracy of 1RM prediction using the load-velocity relationship

Abstract

BackgroundNumerous methods have been proposed that use submaximal loads to predict one repetition maximum (1RM). One common method applies standard linear regression equations to load and average vertical lifting velocity (Vmean) data developed during squat jumps or three bench press throw (BP-T). The main aim of this project was to determine which combination of three submaximal loads during BP-T result in the most accurate prediction of 1RM Smith Machine bench press strength in healthy individuals.MethodsIn this study combinations of three BP-T loads were used to predict 1RM Smith Machine bench press strength. Additionally, we examined whether regression models developed using peak vertical bar velocity (Vpeak), rather than Vmean, provide the most accurate prediction of Smith Machine bench press 1RM. 1RM Smith Machine bench press strength was measured directly in 12 healthy regular weight trainers (body mass = 80.8 ± 5.7 kg). Two to three days later a linear position transducer attached to the collars on a Smith Machine was used to record Vmean and Vpeak during BP-T between 30 and 70% of 1RM (10% increments).ResultsRepeated measures analysis of variance testing showed that the mean values for slope and ordinate intercept for the regression models at each of the load ranges differed significantly depending on whether Vmean or Vpeak were used in the prediction models (P < 0.001). Conversely, the abscissa intercept did not differ significantly between either measure of vertical bar velocity at each load range. The key finding in this study was that 1RM Smith Machine bench press strength can be determined with high relative accuracy by examining Vmean and Vpeak during BP-T over three loads, with the most precise models using Vpeak during loads representing 30, 40 and 50% of 1RM (R2 = 0.96, SSE = 4.2 kg).ConclusionsThese preliminary findings indicate that exercise programmers working with normal healthy populations can accurately predict Smith Machine 1RM bench press strength using relatively light load Smith Machine BP-T testing, avoiding the need to expose their clients to potentially injurious loads.

Using Velocity to Predict the Maximum Dynamic Strength in the Power Clean

“…While the MV is often recommended to be used when analyzing the load-velocity profile, it has been suggested that when looking at ballistic [ 35 ] or semi-ballistic movements, the use of PV may result in more accurate and reliable predictions of the 1-RM [ 36 ]. In the present study when the entire group was examined, there was no significant difference ( p = 0.367, d = −0.11) between the predicted 1-RM (75.5 ± 12.8 kg) and the criterion measure (76.9 ± 13.0 kg) when PV was used in conjunction with a four-point linear regression analysis ( Figure 1 a).…”

“…While some researchers suggest that PV is a more appropriate measure when examining ballistic movements [ 36 , 37 ], like the power clean, an alternative approach is to construct the load-velocity profile using the mean velocity [ 38 ]. García-Ramos et al [ 38 ] have presented data that suggest that MV is the most appropriate variable to monitor during ballistic exercises, such as the bench press throw, performed in a Smith machine.…”

A Novel Approach to 1RM Prediction Using the Load-Velocity Profile: A Comparison of Models

“…Similarly, a simplified two-point version has also been suggested, where 1RM is predicted from two submaximal loads (e.g., 45% and 85% 1RM) [ 17 , 25 ]. Despite differences in the construction of each approach, practically perfect correlations ( r > 0.9), goodness of model fit (R 2 > 0.9), and low systematic bias between direct and predicted 1RM data (<10 kg) have been observed [ 12 , 14 , 17 , 23 , 24 , 26 ]. Whilst these data indicate predictive validity, the studies are limited to isolated, controlled upper body exercises such as the bench press or prone row, rendering the applicability to exercises beyond these unclear.…”

Validity and Reliability of Kinematics Measured with PUSH Band vs. Linear Encoder in Bench Press and Push-Ups

“…This is based on the well-known load-velocity relationship [8,9,10], for which lighter loads are moved at faster velocities and heavier loads are moved at slower velocities. This method has been applied to numerous exercises, with barbell velocity during the bench press and back squat shown to be highly correlated with relative 1 RM training intensity over a wide range of loads [8,9,10,11,12,13]. Thus, the method for monitoring strength training intensities using barbell velocity is a valid approach to training intensity prescription.…”