فهرست مطالب shiva dadvand

Creatine supplementation has been widely used among athletes. The use of resistance training along with dietary supplements are the most widely used methods that improve strength and increase muscle hypertrophy and improve performance in athletes. The aim of this study was to evaluate the effects of resistance training (RT) and supplementation of creatine hydrochloride on muscle strength and body composition in trained women.

In this quasi-experimental and applied study with pretest-posttest design 24 young trained randomly assigned to one of two groups: Group 1: RT with CrHCL supplementation (RT + CrHCL, n=12) and Group 2: RT with placebo (RT+PL, n=12). The participants performed 8 weeks of RT (70–85% one repetition maximum (1RM). 48 hours before and after the training period, muscle strength, body composition and upper body muscle hypertrophy and lower body muscle hypertrophy were measurements. To determine the difference between research variables mixed ANOVA test was used at a significance level of 0.05. 

Significant increases were observed for body weight, fat mass, fat free mass, skeletal muscle mass, upper body muscle hypertrophy and lower body muscle hypertrophy between pre and post-test in the RT + CrHCL group (P<0.05). In addition, percentage of body fat and fat mass was significantly decreased in the post-test in the RT + CrHCL group (P<0.05). The bench press and leg press strength changes in the RT + CrHCL group were significant compared to the RT+PL group (P<0.05, P=0.001, P=0.017). In other variables, despite the significantly increase and decreased in the post-test in the RT+CrHCL group, no significant differences were observed between the two groups (P>0.05).   

It seems that 8 weeks of the CrHCL supplementation as a new type of creatine with RT can have significant effects on muscle strength in young trained women.

Caffeine is one of the most widely used material in the world is, although little nutritional value but as an ergogenic allowed to have attracted the attention of many competitive athletes. The purpose of this study was to investigate the effect of caffeine consumption on muscle strength and endurance in elite middle distance runners. For sampling due to the small population of targeted and available methods were used, the total population of the 14 runners with an average age of 23.32 ± 0.04 years, height of 178.17 ± 1/12 cm, weight of 65.62 ± 1.11 kg and VO2 max 62.32 ± 2.44 ml/kg/min Which has a history of winning competitions in provincial and national championships were attending. To participate in the research and double blind study and randomly divided to two groups: Supplement and placebo. The Supplement group, received 6 mg/kg caffeine and placebo (rice flour). In tests session, the muscle strength and endurance were evaluated with one-repetition maximum and 70% 1RM repetitions tests in Leg press and bench press respectively. Independent t-test was used Showed that the average strength and muscular endurance in the Supplement group was significantly increased compared to placebo. Statistical analysis showed that there was significant increase in strength and endurance in the caffeine group; (P˂0.05). While there were no significant changes in placebo group. Based on these findings, it can be concluded that consumption of 6 mg/kg caffeine significantly improved muscular strength and endurance in the elite middle distance runners.