The Claim

An acute bout of resistance exercise at 80% of one-repetition maximum stimulates mixed muscle protein synthesis by 132% in untrained limbs but does not significantly increase it in trained limbs, even though the trained limbs perform 70-85% more total work volume.

Source: Fasted‐state skeletal muscle protein synthesis after resistance exercise is altered with training

What the research says

Challenges is higher

Challenge is ahead, but a single strong supporting study can change this.

Supports
0score
Challenges
33score

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

Quantitative
1 study reviewed
In plain English

When people lift weights at a high effort level, their untrained muscles build more protein quickly, but their already-trained muscles don't get the same boost, even if they do more work.

See the scientific wording

An acute bout of resistance exercise at 80% 1RM stimulates mixed muscle protein synthesis by 132% in untrained limbs but shows no significant increase in trained limbs, despite the trained limbs performing 70-85% more total work volume.

What the research says

1 study
  1. Study: Fasted‐state skeletal muscle protein synthesis after resistance exercise is altered with training

    The study shows that exercise boosts muscle growth in untrained legs but not trained ones, similar to the claim, but it doesn't give exact numbers like 132%, so the claim might be a bit exaggerated.

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.