With collagen protein, the muscle-building effect was almost identical in the exercised and non-exercised leg—unlike whey, which responded more strongly where exercise happened.

Scientific Claim

In healthy older women, the muscle protein synthetic response to collagen peptides is more strongly correlated between rested and exercised legs than the response to whey protein, suggesting a less targeted or more uniform systemic response.

Original Statement

“There was an association with the acute MyoPS response between Rest and Exercise for both WP (r = 0.74, P = 0.0229) and CP (r = 0.98, P = 0.0002). There was an association with the integrated MyoPS response between Rest and Exercise for both WP (r = 0.93, P = 0.0034) and CP (r = 0.85, P = 0.003).”

From study:Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women: a randomized controlled trial.

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

association

Can only show association/correlation

Assessment Explanation

The study reports correlation coefficients (r-values), not causation. The claim correctly uses 'correlated' and does not imply causation, making it appropriately stated.

Evidence from Studies

Supporting (0)

No supporting evidence found

Contradicting (1)

Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women: a randomized controlled trial.

Randomized Controlled Trial

Human

2020 Mar 1

The study found that collagen peptides only helped muscles grow after exercise, not when resting, while whey protein helped muscles grow both with and without exercise — so collagen is more targeted, not more uniform.

Source Study

Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women: a randomized controlled trial.

Score: 66

DOI: 10.1093/ajcn/nqz332

Similar Assertions

When one leg got whey protein and exercise, the other leg (which didn’t exercise) still showed similar muscle-building activity—meaning the effect was happening all over the body, not just where the exercise happened.

87%

Even with daily exercise, collagen protein shakes didn’t help older women’s muscles build new protein over a week—whey did, but collagen didn’t.

83%

After drinking whey protein shakes every day for a week, older women’s muscles kept building up new protein even on days they didn’t exercise—collagen protein didn’t do this at all.

82%

Doing leg exercises helps whey protein build muscle even more—but even with exercise, collagen protein still can’t match whey’s muscle-building power.

80%

Even though whey protein made muscles build faster, it didn’t change the usual ‘on/off’ switches in muscle cells that are supposed to control growth—suggesting other mechanisms are at play.

79%