The Claim
Chronic resistance training, regardless of proximity to volitional failure, consistently increases motor unit action potential amplitude and surface electromyographic excitation during submaximal fatiguing contractions, indicating greater recruitment of higher-threshold motor units as muscle fatigue progresses, but does not alter the rate or magnitude of this adaptation between low and high RIR protocols.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Long-term strength training increases the electrical activity in muscles during fatiguing exercises, showing that more powerful muscle fibers are activated as fatigue sets in, and this effect is the same whether training is done close to or far from muscle failure.
See the scientific wording
Chronic resistance training, regardless of proximity to volitional failure, consistently increases motor unit action potential amplitude and surface electromyographic excitation during submaximal fatiguing contractions, indicating greater recruitment of higher-threshold motor units as muscle fatigue progresses, but does not alter the rate or magnitude of this adaptation between low and high RIR protocols.
When muscles get tired during repeated contractions, the working muscle fibers lose their ability to produce force, so the nervous system turns on larger, stronger muscle fibers to keep the movement going. These larger fibers produce bigger electrical signals, which show up as higher readings on muscle activity tests.
What the research says
1 studyWhether you train until you can't do another rep or stop a few reps short, your muscles still recruit the same powerful fibers as they get tired — and this study shows both ways work the same way.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.