The Claim

In untrained young men, the magnitude of strength gains in response to increased training volume differs between upper body muscles (elbow flexors) and lower body muscles (knee extensors) during the first six weeks of resistance training, with knee extensors exhibiting greater sensitivity to volume increases.

Source: Early phase adaptations of single vs. multiple sets of strength training on upper and lower body strength gains

What the research says

Supports is higher

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

Supports
54score
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.

Comparative
1 study reviewed
In plain English

In untrained young men, increasing the number of sets during resistance training leads to greater strength gains in the knee extensors than in the elbow flexors over the first six weeks.

See the scientific wording

The effect of training volume on strength gains differs between upper and lower body muscles in untrained young men, with knee extensors showing greater sensitivity to increased sets than elbow flexors during the first six weeks of resistance training.

Why this might work

When untrained men start lifting weights, the muscles in the legs activate more nerve signals and recruit more muscle fibers with each set than the arm muscles do, so adding more sets makes the legs stronger faster.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Early phase adaptations of single vs. multiple sets of strength training on upper and lower body strength gains

    When people start lifting weights, doing more sets helps legs get stronger faster than arms—this study found that legs needed three sets to improve, but arms got just as strong with only one set.

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.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.