Journal of Knowledge & Health in Basic Medical Sciences1735-577X12420180317The Effect of Creatine Supplementation on CK, LDH After a Session Intense Exercise404610.22100/jkh.v12i4.1832FAMahsaSedaghat1*1- Dept. of Physical Education and Sport Sciences, Semnan Branch, Islamic Azad University, Semnan, Iran.. mrashidi48@yahoo.comMohammadRashidi1201712092018022520180217Introduction: One of the causes of fatigue among athletes is accumulation of lactic acid in the blood after a heavy activity. During fatigue, some enzymes such as lactate dehydrogenase (LDH) and creatine kinase (CK) increase and subsequently cellular damage to the active muscles will occur. This is more common among athletes who reach to the maximum activity rapidly in a short time, nearly one to three minutes.Methods: In this study, 30 athlete female students were selected by seven-stage Bruce test and randomly divided into two groups of 15 with random sampling. To this end, each of the subjects who had successfully completed six stages of the seven-stage test, were selected; the first group took creatine supplementation, the second group placebo. Before the beginning of the training program, all subjects were pre-tested. After the blood test, the subjects were asked to take creatine supplement for one week, and the placebo group consumed starch powder during this time. After this period, both groups were subjected to Cunningham test and blood samples were taken again 24 hours after the test, and cellular damage indices were measured by a special kit. Statistical comparisons were performed by SPSS version 16.Results: The results of the independent t-test showed no significant difference between two groups in the delta of CK (p= 0.183). In other words, creatine supplement did not change CK level compared to the control group significantly. Also the results did not report any significant difference between two groups in the delta LDH (p=0.227). It means that creatine supplement did not have an effect on DHL level compared to the control group.Conclusion: The results suggest that a period of creatine supplementation did not change the levels of CK and LDH and so further studies are needed.