Using the Repetitions in Reserve-based Rating of Perceived Exertion Scale to Autoregulate Powerlifting Training
Autoregulation is a training approach where adjustments are made based on the recovery, performance and readiness of the individual. By providing greater individualisation, autoregulation may optimise muscular adaptations. This thesis investigates the practical implementation of autoregulation in strength training to answer the question: “can autoregulation, through the use of the novel rating of perceived exertion (RPE) scale based on repetitions in reserve (RIR), improve the efficacy of powerlifting training?”. First an introduction to powerlifting and the training concepts common to it is undertaken. Then, the history of RPE in powerlifting is detailed, establishing the thesis framework. In Chapter two the body of knowledge on methods of monitoring and regulating resistance training is reviewed. Those methods with strong (r ≥ 0.68) relationships to resistance training performance are highlighted and the need for further investigation into the use of the RIR-based RPE scale in autoregulation is identified. Chapter three is a narrative review of the history of RPE scales in resistance training and the utility of the RIR- based RPE scale. In Chapter four, this scale’s utility when conducting one-repetition maximum (1RM) tests in competitive powerlifters is assessed. Specifically, while similar, near-maximal RPE at 1RM among the powerlifts (9.7-9.8 RPE; p > 0.05) was found, average concentric velocity (ACV) among the squat (0.23 ± 0.05 m·s-1), bench press (0.10 ± 0.04 m·s-1) and deadlift (0.14 ± 0.05 m·s-1) differed (p < 0.05). The relative training volume of powerlifters, when using three levels of the ‘RPE stops’ method to regulate number of sets performed, over a 3-week training period is reported in Chapter five. Briefly, this method sets an RPE-threshold whereby if reached, sets are no longer performed, after a percentage reduction from the first set’s load is implemented. Specifically, 2, 4 and 6% RPE stops were investigated. Weekly combined relative volume load (squat + bench press + deadlift), expressed as sets x repetitions x percentage 1RM differed between weeks (p < 0.001): 2% = 74.6 ± 22.3; 4% = 88.4 ± 23.8; 6% = 114.4 ± 33.4. Chapter six is an analysis of the same cohort of powerlifters’ ability to accurately select loads based on RPE targets during this 3-week period. Overall, post-set RPE scores differed minimally (0.33 ± 0.28 RPE) compared to target RPEs. In Chapter seven, the effectiveness of training with self-selected loads based on a target RPE range versus using a traditional percentage 1RM-based approach for the bench press and back squat was tested in two parallel groups of resistance-trained males for 8 weeks. While both groups increased 1RM and muscle thickness (p < 0.05), differences between groups were non-significant. However, probabilistic analysis of effect size (ES) indicated a greater likelihood (57-79% probability) that RPE-based loading provided small (ES = 0.28-0.50) advantages for improving 1RM strength compared to percentage 1RM- based loading. Additionally, average percentage of 1RM, relative volume and RPE differed during training, as well as subjective recovery. Chapter eight is a summary of the findings, their applications, and future research directions in powerlifting and strength training as a whole.