The Study
Creatine supplementation has no effect on human muscle protein turnover at rest in the postabsorptive or fed states.
This study looked at 6 guys and saw that taking creatine didn’t change how their muscles built or broke down protein — but because it wasn’t a fair test with a placebo group or random assignment, we can’t say creatine definitely caused that. It just shows a possible link, not proof.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Taking creatine doesn't change how fast your muscles build or break down protein when you're resting. But eating food makes your muscles build protein faster and break it down slower. So if creatine helps you grow muscle, it's probably because you work out more, not because your body changes how it uses protein.
Where does this study sit?
Systematic Reviews & Meta-analyses
Max 100Randomized Trials
Max 90Cohort Studies
Max 72Case-Control
Max 58Cross-Sectional
Max 44Case Reports & Series
Max 30Expert Opinion
Max 530 / 100
Quality score
Detailed descriptions of individual patients or small groups. Valuable for identifying new conditions or side effects, but cannot establish generalizable conclusions.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — food has a big effect on muscle protein, but creatine doesn't affect muscle protein at rest, so its muscle-building effect must come from something else, like more exercise.
- 2Creatine raised muscle creatine by 30%.
- 3Food doubled protein building and cut protein breaking down by 40%.
- 4Creatine did nothing to protein building or breaking down.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
American journal of physiology. Endocrinology and metabolism
Year
2003
Authors
Magali Louis, J. Poortmans, M. Francaux, E. Hultman, J. Berré, N. Boisseau, V. Young, Kenneth Smith, W. Meier‐Augenstein, J. Babraj, T. Waddell, M. Rennie
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.