Background and Objectives: Creatine monohydrate (CrM) ingestion is a popular ergogenic aid among young athletes to enhance muscle mass and exercise performance. However, there are controversies about the adverse effects of this supplement particularly cardiovascular system. Therefore, this study was conducted to determine the effect of CrM ingestion during eight weeks of resistance training on serum CK & CKMB in non-athlete men. Materials and Methods: Seventeen non-athlete healthy male volunteers were randomly divided into experimental (n=9) and control (n=8) groups and participated in a randomized and double-blind design. All subjects completed 24 sessions of weight training (3d/w, and 3 sets/10 reps with 75% 1RM) in eight weeks period. Experimental subjects consumed 250 ml Creatine monohydrate supplementation solution (0.07 g/kg/day) during the training protocol, but control group was took placebo (wheat flour). Venous blood samples were obtained before the training and 24 h after the last session of weight training. Serum CK and CKMB activities (IU/L) of samples were measured. Data was expressed as Mean ± SD and statistically analyzed by statistical methods. Results: The results indicate that CK and CKMB activities were significantly increased in experimental group (CKpre: 146.12±14.61; CKpost: 253.66±21.32 IU/L, P<0.001; CK-MBpre: 10.03±1.21; CK-MBpost: 14.63±1.48 IU/L, P=0.007) while, CKMB activity change was not significant in control group (CKpre: 130.33±18.16; CKpost: 162.50±20.53 IU/L, P<0.009; CK-MBpre: 10.72±1.35 IU/L; CK-MBpost: 11.69±2.03 IU/L, P=0.91). Conclusion: This observation suggests that CrM ingestion might have adverse effects on myocardium damage indices. However, more research is needed to identify the acute and chronic side effects of Creatine monohydrate supplementation in the future.

To investigate the effect of low-dose supplementation of creatine monohydrate without the use of the saturation phase, 36 male university students engaged in resistance training (age 22. 5 4. 3 years, height 1. 76 0. 08 m, weight 77. 0 11. 0 kg, and body mass index 24. 6  2. 5 kg/m2) were randomly divided into three groups: group placebo (GP), group supplemented with creatine 3 g/day (3G), and group supplemented with 5 g/day creatine (5G). The subjects were tested formaximummuscle strength (1RM), upper body muscle endurance (MPU), and abdominal muscle endurance (MSU) before and after 7, 14, 21, 28, and 35 days of creatine supplementation or placebo and performing standardized resistance training. After 35 days of supplementation and training, all groups showed a significant improvement in the 1RM test; however, the percentages of strength increase were significantly higher (P < 0. 05) in the groups supplemented with creatine (G3,
% 1RM = 20. 0 4. 0; G5,
% 1RM = 19. 9 1. 5) than in the placebo group (GP,
% 1RM = 10. 3  1. 9). Upper limb muscle endurance showed a significant improvement only in 5G, ranging from 39. 9 7. 9 MPU/min to 50. 7 11. 0 MPU/min after 35 days of supplementation. Interestingly, abdominal muscle endurance showed no increase in any of the groups (GP, P > 0. 528; G3, P > 0. 076; G5, P > 0. 148). These results support a number of earlier studies that demonstrated that creatine supplementation at low doses and without the use of the loading phase are effective for increasing maximal strength and endurance of upper limbs.

Introduction: Fatigue is considered to be one of the main causes of impaired quality of life among patients with multiple sclerosis (MS). Creatine enhances ATP synthesis and possesses antioxidant properties. There has been interest in the use of creatine supplement for fatigue and muscle strength in neurological disorders. It has previously been reported that, using 20 gram/day creatine supplement for 5-7 days followed by 5 gram/day for another 7 days did not ameliorate fatigue in patients with MS. In this study, we aimed to determine whether longer application of creatine supplement would be effective in controlling fatigue in these patients.Materials and Methods: In a double-blind controlled trial, 20 patients with MS with fatigue and mild to moderate disability were randomly assigned to creatine (10 gram, two times a day for 14 days) and placebo (10 patients in each group). Fatigue was assessed at baseline and after 14 days using fatigue severity scale (FSS).Results: No significant differences were observed between FSS score before and after the intervention. Furthermore, no significant difference was observed between the experimental groups in the mean difference of FSS.Conclusion: Creatine supplementation had no significant effect on fatigue score even after longer administration.

The purpose of this study was to determine the effect of creatine monohydrate supplementation on GH, Testosterone and Cortisol secretion. For this reason, 20 swimmer students in university of Kurdestan were selected randomly (age=20.8±2.61) and divided in to two groups: creatine (N1=10) and placebo (N2=10). Creatine group subjects were given 20gr creatine daily (in form of a solution with apple juice, 4 times consisting of 5 gr creatine) for six days. The placebo group subjects were given 12gr flour daily under the same condition of the first one for the same duration. Both groups trained speed swimming during the six days. Blood samples were taken before and after trining program to measure hormone concentrations. The records of swimming (50m) were determined also in pretest and posttest. Analyzing data suing dependent and independent T showed: There was no significant difference between two groups (both pre and posttest) in hormone secretion (GH, Testosterone and Cortisol). But there was a significant difference in two groups (posttest) in Testosteron secretion, that increased significantly in creatine group (P=0.01). There was also a significant decrease in average time of 50m in creatine group (P=0.044).