Creatine may reduce exercise-induced muscle damage Original paper

Creatine is naturally present in meat and fish, and it is synthesized endogenously in the liver from the amino acids glycine, methionine, and arginine. Creatine is also a highly popular supplement among athletes due to its ability to boost high-intensity exercise performance and muscle gain.^[1] Another way that creatine could enhance adaptations to exercise is by enhancing recovery,^[2] but relatively few studies have investigated this outcome.

This meta-analysis of 9 randomized controlled trials examined the effect of creatine supplementation on creatine kinase (CK) and lactate dehydrogenase (LDH) levels — two biomarkers of exercise-induced muscle damage — in healthy adults aged 20–38.

Overall, creatine supplementation significantly reduced CK following exercise (−28.91 U/L) but did not reduce LDH.

In the subgroup analysis, creatine supplementation reduced CK levels at 48, 72, and 96 hours after exercise in untrained participants and when >20 g/day was supplemented for ≤1 week. Additionally, creatine significantly reduced LDH at 48 hours after exercise (−13.89 U/L) and when >20 g/day was supplemented.

There was substantial heterogeneity (>90%) in most of the analyses for CK, which warrants caution when interpreting the results. Also, none of the included studies blinded the researchers, and only one study blinded the participants.