Dear Editor-in-Chief The percentage of Korean college students who participate in some form of physical activity three times a week is only 28. 4%. Adults over the age of 20 yr are the only group that participates in regular exercise on a less frequent basis (22. 8%) than Korean college students (1). Due to time constraints related to their studies and job searches, the amount of time that these students have for physical activity is estimated to be about 18 min per week (2). ...

The aim of this study was to investigate the effect of moderate physical activity on muscular strength, muscular endurance and neurotrophic factors in old rats with movement disorders. In this experimental study, 24 male Wistar rats were randomly divided into three groups: healthy control without exercise, Parkinson without exercise and Parkinson with moderate physical activity. The exercise group performed 4 weeks of moderate physical activity (5 days per week). Muscular strength and muscular endurance were examined by Hanging test and CDNF and BDNF levels were assessed by ELISA method. The difference in the mean of groups was investigated using one-way ANOVA at P<0.05. There was a significant difference among the three groups in muscular strength and muscular endurance. In post hoc tests, it was clear that the rats in the exercise (P=0.001) and healthy control (P=0.001) groups maintained their muscular endurance longer than the movement disorder without exercise group. It was also found that BDNF (P=0.001) and CDNF levels of the exercise group were significantly higher than the untreated group (P=0.001). Based on these results, moderate physical activity can increase neurotrophic factors in the brain and increase and improve muscular strength and muscular endurance in rats with movement disorder. Therefore, it is likely that these exercises can improve movement disorders in the elderly.

The aim of this study was to investigate the effects of endurance training and yoga-based mindfulness intervention on the mental toughness of male and female athletes. In the first phase, 40 physical education students were divided into two experimental groups and two control groups. The experimental group underwent an endurance training program for 5 days, while the control groups did not undergo any type of endurance training. After the end of the training period, all groups underwent a mental toughness test. The results of this section showed that the experimental group that had performed endurance training had significantly more mental toughness than the control groups. Also, the results indicated that mental toughness was higher in men than in women. These findings emphasize the importance of endurance training in strengthening psychological factors, especially mental toughness in athletes, and indicate that such training can help improve sports performance and increase the ability to adapt to psychological pressures. In the second phase, another study examined the effects of yoga-based mindfulness intervention on the mental toughness of athletes with different skill levels. In this study, 72 student athletes were divided into three experimental groups and three control groups. The experimental groups underwent a yoga training program for 12 sessions. After this period, the effect of the intervention on mental toughness and its subscales such as stability and control was evaluated. The results of this study showed that the yoga intervention had a positive and significant effect on mental toughness and its various components, especially in the less experienced and semi-skilled groups. These findings indicate that mindfulness exercises can help strengthen the mental capabilities of athletes and help them face sports challenges. These findings can recommend that coaches and sports professionals use combined training programs, including endurance training and mindfulness interventions such as yoga, to improve the mental toughness of athletes. Finally, strengthening mental toughness not only helps improve sports performance, but can also add to the mental health of athletes and help them on the path to success.

This study performed for evaluation of caffeine intake’s effect after a period of creatine loading on muscular endurance and levels of cortisol and catecholamines. Subjects were 12 athletic students which after completing the consent form, first participated as a control group in assessment of upper body (bench press) and lower body (leg extension) muscular endurance by weight lifting with 70% of one repetition maximum load to failure. After tests, 5cc blood sample were taken from brachial vein for assessment of cortisol, epinephrine and norepinephrin levels. Then, subjects grouped in three position including placebo group, experimental group 1 (0.3 grams of creatine per kilogram of body weight per day for 5 days followed by 6 mg per kg of body weight placebo usage) and experimental group 2 (0.3 grams of creatine per kilogram of body weight per day for 5 days followed by 6 mg of caffeine per kilogram of body weight usage). Again, after participating in all of three positions, the test was repeated. Repeated measure analysis of variance and paired t-tests were used for data analysis. In experimental group 1, only the lower and upper body strength, significant improvements were observed. This study showed that supplementation with creatine and caffeine after loading phase, improves muscular endurance and levels of cortisol and catecholamines and can be useful in athletes.

Background and Aim: The purpose of this study was to investigate the effect of caffeine on muscle strength and endurance in amateur soccer players.Materials and Methods: The research method was quasi-experimental and population research was selected of soccer players leagues of Saveh in 2012. Forty eight athletes were selected (mean BMI=23.8 ± 0.36 kg/m2, weight=76.1 ± 1.22 kg, height=178.5 ± 0.89 cm and age=24.8 ± 0.49 yr.) and randomly divided into two experimental and control groups. After measuring body mass index, the muscle strength and endurance also were evaluated with one-repetition maximum (1RM) test in leg press and 80% 1RM repetitions, respectively.72 hours later, the experimental and control groups consumed caffeine (5 mg/kg) and placebo (Flour) respectively. The same measurements of pre-test session were repeated one hour after supplement consuming.Independent t-test was used to compare the differences between groups and significance level was set as p˂0.05.Results: The results showed that there was significant increase in strength (p<0.0001) and endurance (p<0.04) in the caffeine group; but there were no any significant changes in placebo individuals (p˃0.05).Conclusion: Findings show that consumption of 5 mg/kg caffeine significantly improved muscular strength and endurance in the amateur soccer players.

Background and Aims Accurate assessment of cardiorespiratory function, muscular strength, and endurance seems necessary to be aware of, provide exercise interventions, and prevent subsequent diseases. Therefore, the current research aimed to develop a comprehensive tool for assessing cardiorespiratory, muscular strength, and endurance function in people with intellectual disabilities.Methods The current research is fundamental and practical in terms of purpose. In this study, the psychometrics of 51 specific intellectual disability tests were used to develop a tool for measuring cardiorespiratory function, muscular strength, and endurance. The face validity of the instrument through a 51-test questionnaire by 15 experts and 15 intellectually disabled educators, the content validity through a 51-test questionnaire by 15 experts, and the construct validity through a 19-test questionnaire by 243 intellectually disabled educators were examined. The tool’s reliability was checked through internal, intra-rater, and inter-rater consistency. Internal consistency was estimated by calculating the Cronbach alpha. The intra-rater and inter-rater reliabilities were also checked through the implementation of the tests by 18 people with intellectual disability in three time points and with three raters through the internal correlation index (ICC), confidence interval (CI), and standard error of measurement (SEM). Data analysis was done through exploratory and confirmatory factor analysis with AMOS version 26 and SPSS software, version 22. Results Based on the content validity ratio (CVR) estimation, 19 out of 51 tests had a content validity ratio higher than 0.49, and the rest were excluded. Regarding construct validity, 10 out of 19 tests were removed, and the final 9 tests were approved for evaluating cardiorespiratory function, muscular strength, and endurance. Exploratory factor analysis extracted three latent factors that explained 46.21% of the total variance. Confirmatory factor analysis confirmed the final construct model. The factor analysis results included KMO=0.829 and BT=4706.93 (P<0.0001).Conclusion The current study provided a special set of tests for people with intellectual disability regarding cardiorespiratory assessment (one test), strength (four tests), and muscular endurance (four tests) after psychometry of 51 specific tests. By using this set of tests, it is possible to make an accurate assessment of the physical fitness of the health of people with intellectual disability.