The Study
Creatine supplementation does not affect human skeletal muscle glycogen content in the absence of prior exercise.
This study watched the same 6 men under different conditions to see if creatine changed their muscle sugar levels. It can show what happened in this small group, but it can't prove that creatine never affects muscle sugar in everyone.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
We checked if taking creatine for 5 days helps store more energy sugar (glycogen) in muscles of young guys who eat normally and don’t exercise before.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 537 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This means just taking creatine won’t boost your muscle energy stores unless you also eat lots of carbs or do depleting exercise.
- 2Creatine filled muscles with more creatine but not more glycogen.
- 3Carbs increased glycogen.
- 4After hard cycling, glycogen dropped the same no matter what they took.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of applied physiology
Year
2008
Authors
D. Sewell, Tristan M. Robinson, P. Greenhaff
Related Content
Claims (6)
Taking creatine supplements may help your muscles store more glycogen, which is like a sugar reservoir, and since glycogen holds onto water, your muscles end up holding more water too.
Taking creatine for five days boosts creatine in muscles, but doesn’t change how much glycogen (energy) is used during intense cycling in healthy young guys — so more creatine alone doesn’t help save energy stores during endurance workouts if muscles weren’t already drained.
Creatine might help your muscles store more glycogen, but only if you first do a workout that drains your energy stores — otherwise, it doesn’t do much for glycogen.
Taking 20 grams of creatine a day for five days boosts the amount of creatine in young men's muscles, even if they don’t work out or eat a lot of carbs.
Taking creatine for 5 days doesn’t boost muscle fuel stores in healthy young guys who aren’t working out or eating extra carbs — it needs more than just the supplement to make a difference.
If young, healthy guys take sugar supplements for 5 days, their muscles store more energy, but taking creatine doesn’t do the same — so sugar seems to fill up muscle fuel better than creatine when not working out.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.