The efficacy of repetitions-in-reserve vs. traditional percentage-based resistance training: a 4-week pre-season randomized intervention in elite rugby league players

Abstract

Purpose: This two-experiment study aimed to examine (1) the accuracy and reliability of repetitions-in-reserve and (2) using a randomized trial, the efficacy of repetition-in-reserve compared to traditional percentage-based training during a 4-week pre-season strength training block in elite rugby league players. Methods: In experiment 1, participants performed deadlift, bench press and weighted pull up exercises for 3, 6, and 9 repetitions to failure using self-selected loads. This was undertaken on two occasions, separated by 8-weeks. In experiment 2, participants were randomly separated into either repetitions-in-reserve or percentage-based training groups. They completed a 4-week pre-season training block with training prescribed based on the group to which they were assigned. Measures of body mass and 3 repetition max strength in the aforementioned exercises were measured pre and post intervention. Results: Experiment 1 showed that repetitions-in-reserve exhibited generally acceptable levels of accuracy and moderate-good levels of reliability. However, the deadlift when the required number of repetitions was 6 and 9 and the bench press when number of repetitions was 9 were not associated with acceptable levels of accuracy and reliability, respectively. Experiment 2 showed that there were no differences between repetitions-in-reserve or percentage-based training group for the strength outcomes, although there were significant increases in body mass in the percentage-based group (pre = 85.6 ± 10.6 kg, post = 86.4 ± 10.8 kg). Conclusion: Repetitions-in-reserve is generally associated with acceptable levels of accuracy and moderate-good levels of reliability, although there were some exceptions for the deadlift in relation to accuracy and bench press for reliability. Experiment 2 shows that although there were no differences between groups for the strength-based outcomes, significant increases in body mass in the percentage-based group may make this approach a more effective approach to prepare players for the rigors of the rugby league season.