The Study
Creatine monohydrate ingested daily compared to only on training days on body composition, muscle thickness, and strength after 12 weeks of resistance training: preliminary results
This study tried to see if taking creatine every day is better than only taking it on workout days. It found some small changes in muscle size, but because only six people were in the study, we can't be sure if the results are real or just luck. It's like flipping a coin six times and saying heads is better — you need more flips to know for sure.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Two groups of people lifted weights for 12 weeks and took creatine — one group took it every day, the other only on workout days.
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 554 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The muscle gains were real but small, and taking creatine only on workout days worked just as well as daily dosing for most outcomes.
- 2Both groups got stronger in some muscles (thigh, chest, triceps) and both saw no change in body fat or total muscle mass.
- 3Only the daily group got stronger in one leg movement.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of the International Society of Sports Nutrition
Year
2025
Authors
Ignacio Quiroz, Scott C. Forbes, T. Hayes, Felipe Bermudez, Alan Szinavel, Cristian Campos, Paula Méndez, F. de la Fuente, Claudio Pérez de Tudela, Álvaro Reyes, Bruno Ticozzi, Mauricio Jorquera, josé Gomez-Lopez, D. Candow, Matías Monsalves-Álvarez
Related Content
Claims (5)
In healthy, trained young adults doing 12 weeks of resistance training, taking creatine daily or only on training days leads to increased thickness in the vastus lateralis, pectoralis major, and triceps brachii muscles, but not in the biceps brachii, and does not change body fat percentage or total skeletal muscle mass.
Among healthy, trained young adults doing 12 weeks of strength training, taking creatine daily or only on training days does not change body fat percentage or total muscle mass.
Among healthy, trained young adults who performed 12 weeks of resistance training, taking creatine daily or only on training days did not increase maximal force production during an isometric mid-thigh pull.
In healthy, trained young adults doing 12 weeks of resistance training, taking creatine daily or only on training days led to increased strength in the left leg during knee extension movements, but did not change strength in the right leg or during a whole-body pull test.
Among healthy, trained young adults doing supervised weight training three times a week for 12 weeks, taking 5 grams of creatine every day and taking 5 grams only on training days result in the same increase in muscle thickness of the upper arm, chest, and thigh muscles.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.