This study aimed to investigate the facilitative effect of observational practice combined with mental imagery on learning of soccer dribbling. 140 young boys with the average age of 14,52 (±2,96) and mental imagery score of 48,69 (±5,1), who were unfamiliar with the research task, voluntarily participated in this study. The participants were assigned to homogenous groups according to their pre-tests results as follow: 1- physical practice; 2- observational practice; 3-mental imagery practice; 4-physical-observational practice; 5-physical-mental imagery practice; 6- observational-mental imagery practice and 7- physical-observational-mental imagery practice. Then the participants completed three sessions including ninety trials. At the end of the final training session, an immediate retention test was conducted that followed by a delayed retention test after 48 hours. The results of One-Way ANOVA test indicated that in both immediate and delayed retention tests, the physical-observational-mental imagery group and the physical group had a better performance compared with other groups (p<.05). Furthermore, the combined physical-mental imagery group obtained higher scores in soccer dribbling task in comparison with the combined physical-observational group. The findings support the beneficial effects of cognitive interventions as well as physical practice.

The presented study focuses on the impact analysis of a specific training programme primarily focusing on plyometric exercises for the lower limb explosive power, and the selected parameters of swimming turns. The tested set consisted of performance swimmers (n = 20, men n = 12 and women n = 8) in the average age of 17.3 years, average height of 174.2cm, and average weight of 65.8kg. The tested set was divided into two smaller sets. The experimental set (n = 10) used the training process as an extra experimental factor and the supervision set (n = 10) carried out only the main contents of the training process. The specific training schedule was applied during the period of 8 weeks, three times a week for 20 minutes. The effectiveness of the experimental factor was tested through a selected set of tests, focusing primarily on the lower limb explosive power. Three of the tests were conducted on the dryland using the Myotest machine: T1 – Squat jump (SJ), T2 – Countermovement Jump (CMJ) and T3 – Plyometric jump (PJ). The tests conducted in the swimming pool were: T4 – max. length of floating up after the push off from the turning wall, and T5 – the length of push off after 25m of breaststrokes in the maximum speed with a push off from the wall of maximum floating up. The results pointed out a proportionally higher increase in the experimental set, in which the average percentile improvement of the jump height amounted to 17.7% in T1 (the changes in the supervision set were 0.7%); in T2 the jump height was increased by 22% (the changes in the supervision set were 0.6%); in T3 the time of contact increased by 18.5% (the supervision set showed a decrease by 1.2%), T4 by 14.9% (the changes in the supervision set were 4.1%) and in T5 by 22.7% (the changes in the supervision set were 11.0%). Kendall correlation coefficient (r), pointed out the average value of the correlation coefficient between the experimental factor and the individual tests as follows: T1: r = 0.39, p<0.05; T2: r = 0.41, p<0.05; T3: r = 0.43, p<0.05, T4: r = 0.38, p<0.05 a T5: r = 0.41, p<0.05. In conclusion, practice, improvement, and affectivity of the swimming turn can affect the swimmers’ performance in races and improve it.

One of the most important health problems of today's society is hypokinesia accompanied by obesity. The assumption is that reduced physical activity has a large negative impact on the school population. The problem of reduced commitment and involvement of pupils in extracurricular activities is increasingly evident in recent times, which results in a number of negative health effects on the human body of an individual. This study comprised a group of pupils from first to the fourth year of elementary school in Pale (city East Sarajevo, BIH). The total sample consisted of 175 pupils (84 male and 91 female) age 11 to 14±0,5years. As a way of gathering the required information, we used an anonymous questionnaire of the open type in order to collect information about pupils involvement in extracurricular sports activities. The survey was conducted in October 2017 and all the pupils voluntarily participated in the study. Based on the survey results have been obtained the necessary information to reflect the very good of physical activity, of the pupils population. Of the total sample of pupils, the survey confirmed that 100% are physically active pupils. This is an encouraging result because today we have less physically active school children.

Anthropometric characteristics, represent one of the most important subsystems within the “system” of man, and which can be in affected by physical exercises in the direction of the desired transformation. Very often the anthropometric parameters (height and weight) are used in the assessment of the morphological status of an individual, and on the basis of the results of Body Mass Index (BMI) bring certain estimates and conclusions. BMI as a statistical measures, is used in many public health campaigns as an approximate measure of the ideal body mass and the degree of nutrition of a population. The main goal of the research was to determine and analyze differences in BMI parameters between male and female students, aged 18±0.5 years, and determine the trend of changes. Using the T-test module, the obtained results confi rmed that there are statistically signifi cant differences in body height (t=8,17; p<0.001) and body weight (t=5,29; p<0.001), while in BMI values there are not statistically signifi cant differences (t=-0.68, p>0.001). Based on BMI values, a positive trend of somatic changes of both poles is evident. Research Article The body composition analysis: Differences between students and the trend of their change Ratko Pavlović1*, Zoran Radić2, Irina Juhas3 and Mensur Vrcić4 1Faculty of Physical Education and Sport, University of East Sarajevo, Bosnia and Herzegovina 2Faculty of Physical Education, Sport and Health, University of Skopje, Macedonia 3Faculty of Sport and Physical Education, University of Belgarde, Serbia 4Faculty of Sport and Physical Education, University of Sarajevo, Bosnia and Herzegovina *Address for Correspondence: Ratko Pavlović, Faculty of Physical Education and Sport, University of East Sarajevo, Bosnia and Herzegovina, Email: pavlovicratko@yahoo.com Submitted: 09 March 2018 Approved: 21 March 2018 Published: 22 March 2018 Copyright: 2018 Pavlović R, et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Objectives: Anthropometric traits are closely related to health improvement as well as motor skills, psychological and sociological development. Therefore, the aim of this study was to investigate the differences in anthropometric traits of high school students and trend of changes among them. Methods: The anthropometric parameters including weight, height and body mass index (BMI) were measured in 60 male and female students, aged 17 ± 0.5 years. Descriptive statistics and t-independent test was used to analyze the data. Results: The results suggested that there were statistically significant differences in the height (t = 7.40; P < 0.000) and body weight (t = 3.62; P < 0.001) of male and female students, while no significant difference was found in BMI values in the two groups (t = -0.33, P > 0.001). In addition, it was suggested that 68% of male and female high school with mean BMI of 25 and 13 respectively, had normal nutrition status. 14.6% of male and 10.5% of female students had malnutrition. 21% of female students and 17% of male students had an excessive malnutrition. Conclusions: Although, today’s development is moving towards the advancement of technology, the life style especially nutrition status and physical activity needs to be seriously considered. However, mush research is needed to understand the effective factors on life style of different age groups especially students who are so involved in threaten of hypokinesian lifestyle.