Research

Mixed

Varying proximity-to-failure (progressively decreasing RIR from 4 to 1) does not enhance short-term muscle strength or hypertrophy compared to consistently training at 1 RIR in resistance-trained individuals.

If you are an experienced lifter, you do not need to vary your proximity to failure week-to-week to get stronger or bigger. Training consistently at 1 Repetition in Reserve (RIR 1) produces the same results as a program that starts easy (RIR 4) and gets harder (RIR 1). However, the varying approach results in lower perceived exertion (RPE) during the easier weeks, which may make the training feel less stressful without sacrificing gains.

GoodRefutesHIGH confidence
Varying proximity-to-failure may not enhance short-term RT adaptations... No statistical differences were observed between groups in changes in muscle strength or size.
Olli Martikainen et al. · Journal of Science in Sport and Exercise · 2025

Why this rating

Randomized controlled trial with resistance-trained participants, though the sample size was modest (n=31 completers) and the study was partly unsupervised.

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

DOI 10.1007/s42978-025-00338-8

rct · n=39
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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