Thesis
Criterion validity and test-retest reliability of repetitions-in-reserve across different low-loads in the barbell bench press with blood-flow restriction
Masters by Research, Murdoch University
2024
Abstract
Repetitions-in-reserve (RIR) allows the standardisation of the level of effort across individuals during resistance training. This research investigated the criterion validity and reliability of predicting RIR during low-load resistance training with blood flow restriction (BFR). Twenty participants (10.6±5.8 y training experience) initially completed a one-repetition maximum (1RM) bench press assessment and familiarisation trial, before four experimental trials (20%, 30%, 30%, 40% 1RM). Experimental trials comprised one set of 30 repetitions followed by three sets of 15, with 30 s rest periods, and continuous BFR at 60% arterial occlusion pressure. After 15 repetitions in the final set, RIR was estimated before the set was continued to failure. Differences between estimated RIR and actual repetitions to failure were calculated as the RIRerror. Test-retest reliability of fourth set repetitions and RIRerror was determined using the intraclass correlation coefficient (ICC) and coefficient of variation (CV) from repeated 30% 1RM trials. Differences were assessed by repeated measures ANOVA, and associations were examined via Pearson’s product moment correlations. The fewest fourth set repetitions were performed at 40% 1RM (median [IQR] = 8 [5-16] repetitions), followed by 30% 1RM (30 [19-37] repetitions) and 20% 1RM (90 [53- 114] repetitions). RIRerror was higher at 20% 1RM than at 30% 1RM (52 [23-76] vs 9 [2-15] repetitions; p <0.001) but was not analysed at 40% 1RM (70% of participants completed £ 15 repetitions). The RIR predictions were moderately reliable (ICC: 0.980, CV: 13.6%), but with wide limits of agreement (-7 to 7 repetitions). Repetitions performed in the fourth set was almost perfectly correlated with RIRerror in 20% 1RM (R2 = 0.94) and 30% 1RM trials (R2 = 0.90). The current study suggests that estimating RIR from the 15th repetition of the fourth set is not superior to 1RM training prescriptions for low-load BFR. Results suggest 30% 1RM is likely an appropriate load to begin with for trained individuals using a 75-repetition BFR scheme.
Details
- Title
- Criterion validity and test-retest reliability of repetitions-in-reserve across different low-loads in the barbell bench press with blood-flow restriction
- Authors/Creators
- William Grant
- Contributors
- Brendan Scott (Supervisor) - Murdoch University, Centre for Healthy AgeingPaul Goods (Supervisor) - Murdoch University, Centre for Healthy AgeingBrad Wall (Supervisor) - Murdoch University, Centre for Healthy Ageing
- Awarding Institution
- Murdoch University; Masters by Research
- Identifiers
- 991005723862807891
- Murdoch Affiliation
- Centre for Healthy Ageing
- Resource Type
- Thesis
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