The Study
Creatine uptake in isolated soleus muscle: kinetics and dependence on sodium, but not on insulin.
This study looked at how a muscle from a rat soaked in a test tube soaks up creatine. It tells us how the muscle behaves in a lab, but it doesn’t tell us if taking creatine pills helps people run faster or build muscle.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Muscle cells use sodium to pull creatine inside, like a pump. A chemical that looks like creatine blocks this pump. Insulin doesn't help in a dish. Type I muscle (soleus) grabs creatine better than type II at low levels, but both fill up the same when there's lots.
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 512 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — this shows muscle type and sodium levels matter for how well creatine enters cells, which could affect supplement effectiveness.
- 2Km = 73 μM, Vmax = 77 nmol/h/gww.
- 3Sodium drop cut uptake by 77%.
- 4β-guanidinopropionic acid blocked 82%.
- 5Soleus took up 45% more creatine than type II muscle at 100 μM.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Acta physiologica Scandinavica
Year
1999
Authors
C. A. Willott, M. E. Young, B. Leighton, G. Kemp, E. Boehm, G. Radda, K. Clarke
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.