The Claim
Muscle-specific hypertrophy in the quadriceps differs between training to momentary muscular failure and training with 1- to 2-repetitions-in-reserve, with greater vastus lateralis growth observed with failure and greater rectus femoris growth observed with repetitions-in-reserve, indicating that exercise order and fatigue state influence regional muscle adaptation.
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.
When lifting weights to complete muscle fatigue versus stopping 1-2 reps short, the thickening of different parts of the quadriceps muscle varies: the outer part (vastus lateralis) grows more with fatigue, and the front part (rectus femoris) grows more when stopping short. This difference is linked to how fatigue is managed during the workout.
See the scientific wording
Muscle-specific hypertrophy in the quadriceps may differ between training to momentary muscular failure and training with 1- to 2-repetitions-in-reserve, with slight tendencies toward greater vastus lateralis growth with failure and greater rectus femoris growth with RIR, suggesting exercise order and fatigue state may influence regional muscle adaptation.
When lifting weights until complete failure, the outer part of the thigh muscle gets more activated because fatigue forces the body to use more of its strongest muscle fibers there. When stopping just before failure, the front part of the thigh muscle gets more activated because the body can maintain better control and use more of its faster-twitch fibers there. Over time, this difference in which fibers are used most leads to different amounts of growth in each part of the thigh muscle.
What the research says
1 studyWhen people lift weights until they can't do another rep, their outer thigh muscle (vastus lateralis) grows a tiny bit more. When they stop just before failure, their front thigh muscle (rectus femoris) grows a tiny bit more. The study found these small differences, which matches what the claim says.
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.