The aim of this study was to investigate the effects of the short-term (5 g.kg-1 to 1 week) and long-term (1 g.kg-1 to 4-8 weeks) creatine supplementation (Cr) on the Creatine Kinase (CK), Lactate Dehydrogenaze (LDH) and Aspartate Aminotransferase (AST) plasmatic concentrations of sedentary and exercised (swimming to 80% of the tolerated maximum load) rats. Seventy two Wistar males rats (250 ± 10 g) were equally divided in four groups: sedentary rats without supplementation (CON; n = 18); exercised rats without supplementation (NAT; n = 18); sedentary rats with supplementation (CRE; n = 18); exercised rats with supplementation (CRE+NAT; n = 18). At the end of the first, fourth and eighth weeks six animals of each group were sacrificed. The results demonstrated: 1) improvement of CK, LDH and AST in NAT-1 and CRE+NAT-1 groups vs. CON-1 and CRE-1 groups after the first experimental week; 2) higher values of CK and LDH only NAT-4 group after four experimental weeks; and 3) only AST from CRE-8 group differed from other groups at the end of the eighth experimental week. These findings suggest that the Cr supplementation: 1) does not affect the muscle damage on swimming exercised rats after one week of high intensity training; 2) could be able to reduce the muscle damage after 4 weeks of training; and 3) after eight weeks of Cr supplementation, the muscle damage seems to be attenuated by the exercise, nullifying the effects of Cr.
Ergogenic resource; Muscular damage; Oxidative stress
