Using a Load-Velocity Relationship to Predict One repetition maximum in Free-Weight Exercise: A Comparison of the Different Methods

Abstract

The purpose of this study was to investigate the reliability and validity of predicting 1-repetition maximum (1RM) in trained individuals using a load-velocity relationship. Twenty strength-trained men (age: 24.3±2.9 years, height: 180.1±5.9 cm, body mass: 84.2±10.5 kg) were recruited and visited the laboratory on three occasions. The load-velocity relationship was developed using the mean concentric velocity of repetitions performed at loads between 20% and 90% 1RM. Predicted 1RM was calculated using 3 different methods discussed in existing research; minimal velocity threshold 1RM (1RMMVT), load at zero velocity 1RM (1RMLD0) and force-velocity 1RM methods (1RMFV). The reliability of 1RM predictions was examined using intraclass correlation coefficient (ICC) and coefficient of variation (CV). 1RMMVT demonstrated the highest reliability (ICC=0.92-0.96, CV=3.6-5.0%), followed by 1RMLD0 (ICC=0.78-0.82, CV=8.2-8.6%) and 1RMFV (ICC=-0.28-0.00, CV= N/A). Both 1RMMVT and 1RMLD0 were very strongly correlated with measured 1RM (r=0.91-0.95). The only method which was not significantly different to measured 1RM was the 1RMLD0 method. However, when analyzed on an individual basis (using Bland-Altman plots), all methods exhibited a high degree of variability. Overall, the results suggest that the 1RMMVT and 1RMLD0 predicted 1RM values could be used to monitor strength progress in trained individuals without the need for maximal testing. However, given the significant differences between 1RMMVT and measured 1RM, and the high variability associated with individual predictions performed using each method, they cannot be used interchangeably; therefore, it is recommended that predicted 1RM is not used to prescribe training loads as has been previously suggested.

Load-velocity Profiles Change after Training Programs with Different Set Configurations

“…An interesting finding of this study was that L 0 was unaffected by both training programs. This parameter has been previously used for estimating the 1RM of both BP [32] and free weight parallel squat exercises [16]. In this regard, our results suggest as tentative L 0 values of 115, 133, and 120 % of 1RM for BP, SQ, and SQ-SM, respectively.…”

“…Assuming that each percentage of 1RM ( %1RM) is always associated with a given velocity [10,11], different general load-velocity (LV) equations have been previously developed to estimate the %1RM from the recorded velocity with a sub-maximal load [10,12,13]. However, there are some limitations with this approach as: i) an important inter-subject variability in the LV relationship has been previously reported [14][15][16][17][18], ii) low reliability has been observed for the velocity associated to 1RM (V 1RM ) [16,19,20], and iii) the force-velocity relationship analysis has detected a high inter-subject variability for the intercept of the velocity axis and therefore, for the estimated velocity without external load [21,22]. Based on these limitations, the use of individual better than general LV equations has been suggested [14,17].…”

Effects of velocity loss in the bench press exercise on strength gains, neuromuscular adaptations, and muscle hypertrophy

“…15,16 However, it should be noted that velocity-based predictions conducted on freeweight exercises are not always accurate. 17,18 Secondly, using only the velocity attained at a given %1RM is not a proper method to predict the MNR that can be completed with such load. 19 However, the velocity loss (VL) incurred within the set, calculated as the relative difference between the fastest repetition velocity and the last repetition velocity of the set, 7 has shown strong correlations (R 2 = .96) with the percentage of completed repetitions with respect to the MNR.…”

Comparison of the bench press one-repetition maximum obtained by different procedures: Direct assessment vs. lifts-to-failure equations vs. two-point method

“…time consuming or physically and psychologically demanding) have promoted the proliferation of different strategies for predicting the 1RM. 3–6 First studies proposed 1RM prediction equations based on the maximum number of repetitions completed to failure with a submaximal load (i.e. lifts-to-failure method).…”