Proximity To Failure And Repetitions Per Set Effect Rpe Accuracy In The Squat, Bench Press, And Deadlift

Abstract

The repetitions in reserve (RIR)-based rating of perceived exertion (RPE) scale has gained significant popularity. Previous data has shown that intra-set RIR predictions become more accurate closer to failure. However, research has yet to examine this concept in the deadlift. PURPOSE: This investigation examined proximity to failure and total repetitions per set on intra-set RPE accuracy. METHODS: Ten males (age: 25.0±4.0yrs, body mass: 84.1±14.3kg, training age: 6.9±4.0yrs) performed 4 sets to failure at 80% of one-repetition maximum (1RM) on the squat, bench press, and deadlift in successive weeks; in a counterbalanced order. During all sets, subjects indicated when they believed to be at a 6 and 9RPE (i.e. 4 and 1RIR). The RIR difference (RIRDIFF) was calculated by subtracting the predicted number of repetitions from the actual number of repetitions performed. Thus, if 10 repetitions were performed, but a 9RPE was called after 7 repetitions (predicting 8 repetitions), then the RIRIDFF would have equaled 2 (i.e. RIRDIFF=10-8). The RIRDIFF at the called 6 and 9RPE was analyzed with a paired t-test and Pearson’s correlations were used to assess the relationship between repetitions per set and RIRDIFF; significance was set at p≤0.05. RESULTS: The RIRDIFF across all sets of all exercises and within each individual exercise was significantly lower (p<0.01) at the called 9 vs. 6RPE. Across all squat sets the RIRDIFF at 6RPE was 1.00±1.13 vs. 0.67±0.69 at the called 9RPE (p=0.04, effect size-ES=0.35). Bench press RIRDIFF across all sets was 0.84±0.81 at the called 6 vs. 0.51±0.58 at the called 9RPE (p<0.01, ES=0.46). Additionally, deadlift had an RIRDIFF of 1.12±1.05 at the called 6RPE vs. an RIRDIFF of 0.56±0.70 at the called 9RPE (p<0.01, ES=0.62). Total repetitions performed per set were significantly related to a higher RIRDIFF (i.e. more inaccurate RPE ratings) on squat at 6RPE (r=0.47, p<0.01), and bench at 6RPE (r=0.50, p<0.01) and bench at 9RPE (r=0.60, p<0.01). There was no relationship between repetitions performed and RIRDIFF at the squat called 9RPE or either called RPE on the deadlift (p>0.05). CONCLUSIONS: These results suggest that intra-set RPE ratings are more accurate closer to failure on all three exercises and that more repetitions per set may lead to more inaccurate RIR predictions on the squat and bench press.