جستجوی مقالات مرتبط با کلیدواژه « مکمل کراتین » در نشریات گروه « تربیت بدنی »

The aim of the present study was to determine the effect of creatine supplementation along with two types of recovery (in-and-out of water) on C-reactive protein (CRP) and malondialdehyde (MDA) as systemic inflammatory indices and lipid peroxidation and also swimming record in trained female swimmers. In this semi-experimental study, 16 trained female swimmers were divided randomly into two groups: in-water active recovery and out of water active recovery. They performed 6 bouts of 50m sprint swimming with 120s rest intervals actively in-out of water, in-and-out of water before and after 6 days of creatine supplementation. The three-way analysis of variance showed that 6 bouts of sprint swimming significantly increased MDA and CRP (P=0.001). Although the recovery type (in-and-out of water) had no significant effects on MDA, CRP and sprint swimming performance, creatine supplementation significantly reduced MDA (P=0.018) and improved swimming performance (P=0.006) in both recovery groups. It seems that specialized and non-specialized recovery strategies do not affect inflammation and stress inhibition resulted from HIIT, but creatine supplementation can reduce the systemic stress resulted from HIIT and maintain sprint swimming performance.

 Purpose

The aim of this study was to determine the acute effect of HMB and Creatine supplementation on the oxidant and antioxidant indices on trained men after resistance exercise.

10 active men with a mean age of 20±1.15 years, height: 172.2±4.82 cm, weight: 70.9±9.66 kg and body mass index: 24.04±2.44 kg/m2 was purposefully selected and then in a crossover clinical trial design was randomly divided into 4 groups. Resistance exercises including bench press, leg extensions, barbell curl, triceps extension, shoulder press and lat pull down were carried out at 80% 1RM. Prior to each resistance exercise session, subjects were randomized to Creatine, Creatine+HMB, HMB or placebo loading for 5 days. One-week washout was considered between supplementation periods. A day after the completion of each supplementation courses, blood samples were taken in the fasting state (both pre-exercise and immediately post exercise) to evaluate the
effect of supplementation on current research variables.

The results using ANOVA with repeated measurements showed that ingestion of creatine, HMB, or combined supplements has no effect on the serum levels of uric acid, bilirubin, malondialdehyde and glutathione peroxidase.

Overall, the present research findings suggest that short term (5 days) creatine, HMB and combined Cr + HMB has no effect on the oxidant and antioxidant variations following acute resistance exercise

The purpose of this study was to examine the efficacy of creatine consumption on body composition, anaerobic power and muscular endurance of elite wrestlers. Thirteen elite wrestlers (aged 21.09±2.91 years; height 175.63±3.97 cm; weight 78.6±4.6 kg) in a randomized and semi experimental design were divided into experimental (n=7) and control (n=6) groups. Experimental group ingested 20 grs CrM for 5 days and then 5grs CrM for 25 days; while control group in this period ingested placebo. Measurement of weight, fat percent (under skin fat of abdomen, triceps and Ilium), fat mass, fat free mass, upper body and lower body anaerobic power, muscle endurance of abdominal and shoulder muscles was measured in 3 phase (pre test, after 5 days and after 30 days). Data were analyzed by using Analysis variance repeated measure. Results showed that consumption of 20 gr /day creatine for 5 days (loading phase) result in significant increase in weight, fat free mass and upper body anaerobic power (P<0.05) and there was no significant change in fat percent, fat mass, lower body anaerobic power and muscle endurance (P>0.05). Consumption of 5 gr creatine per day for 25 days (maintenance phase) result in no significant change in any factors of study than loading phase (P>0.05). Notice to the results, It seems that creatine loading result in significant increase in weight, fat free mass and upper body anaerobic power of elite wrestler and however maintenance phase result in no significant increase in these factors, but remain loading phase changes.

The aim of this study was to examine the concurrent consumption of creatine and resistance training on flexion strength of biceps brachii in female physical education students in their last semester. For this purpose، 30 students were randomly selected and divided into three groups: the experimental group 1 (age: 19. 8 ± 1. 4 yr، weight: 53. 9 ± 4. 4 kg، height: 162 ± 4. 4 cm)، experimental group 2 (age: 19. 6 ± 1. 3 yr، weight: 51. 2 ± 7. 5 kg، height: 162. 8 ± 5. 2 cm) and control group (age: 19. 8 ± 1. 0 yr، weight: 59 ± 3. 9 kg، height: 162 ± 4. 9 cm). All three groups performed the pretest and posttest after 6 weeks to measure the flexion strength of biceps brachii using a dynamometer. Experimental groups 1 and 2 participated in the 6-week McQueen resistance training program while experimental group 1 consumed creatine supplement and experimental group 2 consumed placebo. The control group did not participate in any training intervention and did not consume any supplements and placebo. To analyze the data within a group، dependent t test and among the groups، one-way ANOVA was used with SPSS ver. 18. The results showed that in the experimental group 1، the flexion strength of biceps brachii increased significantly after 6 weeks of concurrent consumption of creatine supplement and resistance training (P=0. 004). In the experimental group 2 (placebo)، no significant differences were observed in the amount of the strength of this muscle (P=0. 242). In the control group، strength significantly decreased (P=0. 001). In general، it can be concluded that the concurrent consumption of creatine supplement and resistance training can be beneficial in order to increase strength، especially for better performance in sport events.

The effect of creatine (Cr) supplementation on exercise induced-lactate is still debatable. Thus, the aim of this study was to examine the effect of creatine supplementation on blood lactate levels after an exhaustive aerobic exercise. Twenty healthy young men (age: 22.4±0.8 years; weight: 71.8±8.5 kg; body mass index (BMI): 23.5±2.5 kg/m2; maximum oxygen uptake: 37.7±7.2 ml.kg-1.min-1; mean±SD) were randomly assigned to either a creatine (20 g Cr for 7 days) or a placebo group (same dosage of a glucose polymer) using a double-blind research design. After a week of supplementation, the subjects underwent an exhaustive aerobic exercise. Blood samples were taken before the exercise and immediately, 10 and 20 minute after the exercise. The results showed that body weight, BMI, lean body mass and creatine levels were increased significantly after supplementation in the creatine group (P<0.05). Blood lactate levels increased significantly after the exercise in both groups (P<0.05). Blood lactate levels decreased 10 minutes after the exercise in both groups (P<0.05) and the decrease in the creatine group was greater than in the placebo group (P<0.05). The decrease of blood lactate levels continued to 20 minutes after the exercise (P<0.05) and the decrease in the creatine group was greater than in the placebo group (P<0.05). Creatine supplementation may be effective for faster lactate removal after the exercise. However, additional research is needed.

The purpose of this study was to investigate the effect of four weeks interval training with creatine supplementation on body composition and sprint performance in amatory female swimmers.

Subjects
consist of 30 female from Ahvaz City (average age: 22/10 ± 1/41 , mean weight: 57 ± 6/31 kg) were selected and randomly divided in three equal groups of supplement, placebo and control. The subjects in supplement group ingested 20gr (2×10gr per day) creatine supplement per day for five days (loading phase) and then ingested 2gr per day for 25 day (maintenance phase). In placebo group, the subjects ingested the same dose of placebo at the same time. The supplement and placebo groups participated in swimming interval training by 85_90% of maximum heart rate for four weeks. The control group didn’t ingested supplement and didn’t participate in training. body compositions factors of subjects were evaluated by performed body composition test and for evaluation the sprint performance, subjects performed the 25m swimming test. All of the subjects performed these tests before and after 4 weaks training.

The results suggested that four weeks interval training with creatine supplementation lead to no significant changes in body compositions factors in supplement and placebo groups. But four weeks interval training with creatine supplementation lead to significant changes in sprint performance in supplement and placebo groups.

Therefore these results suggest that creatine supplementation lead to increase in muscle creatine reserve, improvement in ATP-Pc system and then lead to improvement in intensive short distance performance. In the other hand, the subjects were amatory and one of the factors that improved the records of sprint performance (in tow groups) may be learning and effects of training.

Background and

Creatine supplementation in young athletes has been widespread. The aim of this study, then, was to determine the effect of creatine supplementation on some performance indexes on young soccer players.

Seventeen young soccer players (age: 17.18 ± 1.37 y, height: 169.6 ± 6.17 cm and weight: 61.67 ± 1.37 kg) participated in this study. Subjects were assigned to either a creatine (5 g of Cr, 4 times per day for 7 days) or a placebo group (same dosage of a glucose polymer) using a double-blind research design. Before and after supplementation, anaerobicpower of legs, muscle strength, agility and dribbling were measured with valid tests. The independent and dependent t tests were used for data analysis.

Results showed that the weight and lean body mass increased significantly in the creatine group (P<0.01), in the placebo group was not significant. On the other hand, resultsshowed that the time of agility (P<0.001) and dribbling (P<0.04) test improved significantly in the creatine group (P<0.05). Anaerobic power of leg (P<0.002) and muscle strength (P<0.001)were increased significantly in creatine group, but mean different between two groups were not significant.

In conclusion, creatine supplementation improves on some performance indexes on young soccer players.

Creatine and Glutamine are supplements that involve in protein metabolism. The present study examined the effects of creatine and creatine-glutamine supplementation on the physiological and anthropometric characteristics of the elite wrestlers. For this reason, 36 wrestlers volunteered in Mazandaran province. They were divided in three homogeneous groups including creatine group as the experiment group 1 (n=12), creatine-glutamine group as the experiment group 2 (n=12) and placebo group as the control group (n=12). In a pretest-posttest design,  strength, peak power, average power, total work performed) were measured. For data analysis, Kolmogorov- Smirnov test, Repeated Measure and one-way ANOVA were used (p<0.05) to measure examine the distribution of normalized samples and compare the mean difference between groups respectively used. The Results showed that there were not significant differences in weight, BMI, body fat percentage, peak power, average power and total work performed between both experiment groups and control group. But There was a significant difference in maximal strength between both experimental groups and control group (p=0.040) but it was not significant difference between the experiment groups (p=0.60). It was concluded that creatine supplement and creatineglutamine supplement influences maximal strength and it is suggested to be used by the athletes.

The purpose of this study was to investigate the effects of short term creatine monohydrate as an ergogenic supplement on the sprint performance and muscular strength of wrestlers. 20 wrestlers were selected randomly and divided into two groups. One group was placebo group (control) and the other group was creatine supplement group (experimental). In a double blind project, subject's speed running, perseverance in repeated alternative speeds and muscular strength (with 1-RM in knee extension) were measured before creatine and placebo as pretest, and after that as posttest. Creatine and placebo were used for 7 days (20 grams creatine monohydrate per day by experimental group and 20 (g/d) dextrose polymer as placebo by control group).The data were analyzed by correlated t – test (for each group) and independent t-test (between two groups). The results showed that short term use of creatine supplement had a significant effect on short term running (20 and 40 meters), long term running (60 and 100 meters), interval speed endurance running (30 fast running in 5 seconds with 10 seconds of rest between each running) and muscle strength (1-RM in knee extension) of wrestlers (p<0.05).

The purpose of this study was to examine the effect of a tapering period and a tapering period along with creatine supplementation on physical performance and body composition of soccer players.

Eighteen soccer players of the first division league (age, 18.77±1.26 years; height, 174.5±5.77 cm; weight, 64.07±6.99 kg) who were in the specific preparation period were selected. At the end of specific preparation period and before a 10 day tapering period, physical performance tests including vertical jump, lower leg strength, 60 meter dash, agility and body composition analysis were performed. Then, participants were divided into two groups: Taper alone (n=9) and taper with creatine supplementation (n=9). After 10 day taper all tests similar to pre-tests were repeated. Dependent student t-test was used to compare the mean differences for pre- and post-test data. Furthermore, independent student t-test was used to compare the data for two groups.

Results showed that taper resulted in a significant increase in speed (P 0.030), strength (P=0.003) and agility (P=0.007) but there were no significant changes in explosive power, agility, fat mass and lean body mass. Furthermore, when the data for two groups were compared there was no significant difference between two groups for all measured variables.

In conclusion, it appears that a tapering period have beneficial effects on physical performance of soccer players, though, consumption of creatine supplementation cannot induce any significant improvements.