The Claim

Resistance training using knee extension exercises induces non-uniform hypertrophy in the vastus lateralis muscle, with greater increases in the distal region (13–14%) compared to the proximal region (9–12%) in healthy young men, suggesting exercise selection may influence regional muscle adaptation.

Source: Regional morphological adaptations of vastus lateralis muscle in response to different progressive resistance training programs: A randomised controlled trial

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
72score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

How it works
1 study reviewed
In plain English

When healthy young men perform knee extension exercises as part of resistance training, the thickening of the vastus lateralis muscle is greater in the lower part of the muscle than in the upper part.

See the scientific wording

Resistance training using knee extension exercises induces non-uniform hypertrophy in the vastus lateralis muscle, with greater increases in the distal region (13–14%) compared to the proximal region (9–12%) in healthy young men, suggesting exercise selection may influence regional muscle adaptation.

Why this might work

When you do knee extensions, the part of the thigh muscle closest to the knee gets worked harder because the way your leg moves makes the fibers near the knee stretch and contract more forcefully. This pulls more muscle fibers into action, especially the strong ones that grow bigger, so that part of the muscle ends up growing more than the part near the hip.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Regional morphological adaptations of vastus lateralis muscle in response to different progressive resistance training programs: A randomised controlled trial

    When people do leg extension exercises, the part of the thigh muscle closest to the knee grows more than the part near the hip — and this study proved it using scans before and after training.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

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