Research

Adherence

Resistance-trained individuals have acceptable baseline accuracy in estimating Repetitions in Reserve (RIR), and this accuracy improves further when using a varying proximity-to-failure protocol (RIR 4-1).

If you are an experienced lifter, you can trust your ability to estimate how many reps you have left in the tank (RIR). You don't need to start from scratch. Using a training program that varies your intensity (starting easier and getting harder) can actually help you get better at estimating RIR, making your training more precise and effective.

GoodSupportsHIGH confidence
RIR1-4 reduced their RIR3 error in the squat... and in the bench press... The changes in RIR1 were not statistically significant... RIR accuracy is already acceptable at baseline in resistance-trained individuals and that it may be further improved by RT, supporting its use to guide training practices.
Olli Martikainen et al. · Journal of Science in Sport and Exercise · 2025

Why this rating

Direct measurement of RIR error with statistical significance for the RIR1-4 group.

Source

Influence of Varying Proximity-to-Failure on Muscular Adaptations and Repetitions-in-Reserve Estimation Accuracy in Resistance-Trained Individuals

Olli Martikainen et al. · Journal of Science in Sport and Exercise · 2025

rct · n=39
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