Proximity to Failure and Total Repetitions Performed in a Set Influences Accuracy of Intraset Repetitions in Reserve-Based Rating of Perceived Exertion. (February 2021)

• Record Type: Journal Article
• Authors: Zourdos, Michael C.; Goldsmith, Jacob A.; Helms, Eric R.; Trepeck, Cameron; Halle, Jessica L.; Mendez, Kristin M.; Cooke, Daniel M.; Haischer, Michael H.; Sousa, Colby A.; Klemp, Alex; Byrnes, Ryan K.
• Is Part Of: Journal of strength and conditioning research. Volume 35:Supplement 1(2021)
• Publication Date: 2021-02
• Subjects: resistance training -- autoregulation -- strength -- fatigue -- individualization -- program design; Physical education and training -- Periodicals; Weight training -- Physiological aspects -- Periodicals; Physical fitness -- Periodicals; 613.7
• DOI: 10.1519/JSC.0000000000002995
• Languages: English
• ISSNs: 1064-8011

Abstract

Abstract : Abstract: Zourdos, MC, Goldsmith, JA, Helms, ER, Trepeck, C, Halle, JL, Mendez, KM, Cooke, DM, Haischer, MH, Sousa, CA, Klemp, A, and Byrnes, RK. Proximity to failure and total repetitions performed in a set influences accuracy of intraset repetitions in reserve-based rating of perceived exertion. J Strength Cond Res 35(2S): S158–S165, 2021—The aim of this study was to assess the accuracy of predicting repetitions in reserve (RIR) intraset using the RIR-based rating of perceived exertion (RPE) scale. Twenty-five men (age: 25.3 ± 3.3 years, body mass: 89.0 ± 14.7 kg, height: 174.69 ± 6.7 cm, and training age: 4.7 ± 3.2 years) reported to the laboratory. Subjects performed a 1 repetition maximum (1RM) squat followed by one set to failure at 70% of 1RM. During the 70% set, subjects verbally indicated when they believed they were at a 5RPE (5RIR), 7RPE (3RIR), or 9RPE (1RIR), and then continued to failure. The difference between actual repetitions performed and participant-predicted repetitions was calculated as the RIR difference (RIRDIFF). The average load used for the 70% set was 123.10 ± 24.25 kg and the average repetitions performed were 16 ± 4. The RIRDIFF was lower (RPEs were more accurate) closer to failure (RIRDIFF at 9RPE = 2.05 ± 1.73; RIRDIFF at 7RPE = 3.65 ± 2.46; and RIRDIFF at 5RPE = 5.15 ± 2.92 repetitions). There were significant relationships between total repetitions performed and RIRDIFF at 5RPE ( r = 0.65, p = 0.001) and 7RPE ( r = 0.56, p = 0.004), but not at 9RPE ( r = 0.01, p = 0.97). Thus, being farther from failure and performing more repetitions in a set were associated with more inaccurate predictions. Furthermore, a multiple linear regression revealed that more repetitions performed per set was a significant predictor of RIR prediction inaccuracy at the called 5 ( p = 0.003) and 7 ( p = 0.011) RPEs, while training age ( p > 0.05) was not predictive of rating accuracy. These data indicate RIR predictions are improved during low to moderate repetition sets and when there is close proximity to failure.