Eligibility Criteria
Articles were elected using criteria of
Population-Intervention-Comparator-Outcomes-Study design (PICOS)
(25) including: 1) healthy subjects
received oral creatine supplementation, as a nutritional strategy; 2)
original randomized-controlled trial researches; 3) reporting at least
one measurement of muscle damage indices (creatine kinase (CK) and
lactate dehydrogenase (LDH)); 4) provided muscle damage indices data as
mean and standard deviation (SD) in both intervention and placebo
groups. Also, criteria for exclusion were: 1) using a mixture of
creatine in intervention group only (vitamins, Coenzyme Q10 and etc.);
2) semi experimental, trials without control groups and nonrandomized
trials; 3) animal studies; 4) reviews and case reports