Santos · Life sciences 2004 · controlled trial · n=?

The effect of creatine supplementation upon inflammatory and muscle soreness markers after a 30km race.

Cited 162 times in the scientific literature.

Level 3 - non-randomized controlled study

Controlled trial; randomization and blinding procedures are not specified in the abstract.

PubMed 15306159 · doi:10.1016/j.lfs.2003.11.036 · record verified 2026-08-29

What was done

Experienced marathon runners (personal best between 2.5 and 3 hours) were given either creatine supplementation (4 doses of 5 g creatine plus 15 g maltodextrin daily) or a control supplement (maltodextrin alone) for 5 days before a 30 km race. Pre-race blood was collected immediately before the race, and post-race blood was drawn 24 hours later to measure markers of cell damage and inflammation: creatine kinase (CK), lactate dehydrogenase (LDH), prostaglandin E2 (PGE2), and tumor necrosis factor-alpha (TNF-alpha).

What was found

After the 30 km race, the control group experienced increases in plasma CK (4.4-fold), LDH (43%), PGE2 (6.6-fold), and TNF-alpha (2.34-fold). Creatine supplementation attenuated the post-race elevations in CK (by 19%), PGE2 (by 60.9%, p < 0.05), and TNF-alpha (by 33.7%, p < 0.05), and abolished the increase in plasma LDH. No side effects (cramping, dehydration, diarrhea) were reported.

Why it matters

Five days of creatine loading before prolonged running blunts systemic inflammatory cytokines and circulating markers of muscle cell injury without impairing running performance.

Limits

The abstract does not state the sample size (n), nor does it specify whether allocation was randomized or blinded. Subjective muscle soreness was not directly reported despite the title.

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