The Claim

In older men, leucine supplementation increases the phosphorylation of p70S6K1 after resistance exercise compared to an isonitrogenous control, indicating enhanced activation of the mTOR signaling pathway.

Source: Enriching a protein drink with leucine augments muscle protein synthesis after resistance exercise in young and older men.

What the research says

Supports is higher

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

Supports
46score
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

In older men, taking leucine after weight training leads to higher levels of p70S6K1 phosphorylation than taking a control substance with the same nitrogen content, which reflects greater activation of the mTOR signaling pathway.

See the scientific wording

In older men, leucine supplementation increases the phosphorylation of p70S6K1 after resistance exercise more than an isonitrogenous control, suggesting enhanced activation of the mTOR signaling pathway.

Why this might work

After resistance exercise, leucine from the bloodstream enters muscle cells and binds to a sensor that turns on a key growth switch called mTORC1. This switch then activates p70S6K1 by adding a phosphate group, which tells the cell's protein-making machinery to work faster. As a result, more muscle proteins are built, especially in older men.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Enriching a protein drink with leucine augments muscle protein synthesis after resistance exercise in young and older men.

    In older men, adding leucine to a protein drink after working out turns on a muscle-building signal stronger than adding another amino acid. This means leucine helps muscles respond better to exercise.

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.