The Claim

In healthy adults over 65 years of age, light-intensity resistance training three to five times per week combined with daily whey protein supplementation increases dynamic knee extensor strength by approximately 13.7 Nm over one year compared to protein supplementation alone, but does not increase quadriceps muscle size.

Source: The effect of daily protein supplementation, with or without resistance training for 1 year, on muscle size, strength, and function in healthy older adults: A randomized controlled trial.

What the research says

Supports is higher

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

Supports
70score
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.

Cause and effect
1 study reviewed
In plain English

In adults over 65, doing light resistance training three to five times a week with daily whey protein increases knee strength by about 13.7 Nm after one year compared to taking whey protein alone, but does not increase the size of the quadriceps muscle.

See the scientific wording

In healthy adults over 65 years of age, light-intensity resistance training three to five times per week combined with daily whey protein supplementation increases dynamic knee extensor strength by approximately 13.7 Nm over one year compared to protein supplementation alone, but does not increase quadriceps muscle size.

Why this might work

Doing light leg exercises with protein shakes makes the nerves that control leg muscles fire more efficiently, so the muscles produce more force without getting bigger. The protein helps keep the connections between nerves and muscles working well.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: The effect of daily protein supplementation, with or without resistance training for 1 year, on muscle size, strength, and function in healthy older adults: A randomized controlled trial.

    In older adults, doing light weight exercises a few times a week with protein shakes made their leg strength a bit stronger, but their thigh muscles didn’t get bigger — just like the claim says.

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.