Studies concerning the effects of different invasion games on physical fitness in school children are scarce. Consequently, the purpose of this study was to examine the effects of the application of invasion games on physical fitness in primary school children. A total of 62 primary school children aged 10-12 years voluntarily participated in this study. They were divided into experimental (32) and control (30) group. Physical fitness of children was estimated by the following tests: Standing broad jump, Vertical jump, Bent-arm hang, Sit-ups, Push- ups, Medicine ball test and Andersen test. The experimental group had twice per week invasion games on non-consecutive days for 12 weeks. Participants in control group did not perform specific program but attended their regular PE class twice per week. Compared with initial measurement, there was a significant (p < 0.05) improvement in vertical jump test for both groups. Furthermore, the group that participated in the invasion games program made significantly greater gains compared to the control group (p < 0.05) in Standing broad jump (8.2%; ES=0.56 vs. 3%; ES=0.2) and Medicine ball test (8.2%; ES=0.6 vs. 3%; ES=0.3). There was a significant improvement in bent arm hang, sit ups and push-ups in experimental group. Compared with initial measurement, there was a significant (p < 0.05) improvement in Andersen test in invasion games group, which was not the case with control group (p>0.05). To conclude, invasion games were an effective way of improving physical fitness in primary school children, because the results of this study indicate that this method was more effective for physical fitness than traditional school program. 

Measuring of morphological characteristics and motor abilities was performed on the sample of 51 male students of the secondary traffic school “Pinki” from Novi Sad.  Body height and body mass were used for measuring of morphological characteristics, and results of standing long jump and running at 30 meters with standing start were used for measuring of motor abilities. The body mass index was calculated after the results were obtained. The aims of the study were to establish and analyze differences in the results of morphological status and explosive strength of students measured in different periods, in the first measurement when the subjects were 15 years old and in the second measurement when the subjects were 17 years old. The data obtained in the study were analyzed using repeated measures ANOVA. The obtained results indicate the existence of statistically significant differences between first and second measurement in all morphological characteristics and motor abilities, at the level of significance of p<0.05.A significant increase in morphological characteristics and motor abilities with age, indicating that boys have adequate growth and development for their age.The age factor has a significantly stronger influence than the factor of the curriculum for the physical education in this high school. 

The aim of this research was to examine differences in the use of self-handicapping strategies in athletes and non-athletes, changes in self-handicapping strategies that can occur with the approach of an important event, and the relationships between these strategies and personality traits, gender, and some external criteria such as performance. The sample included 183 subjects (mean age 21.16 years) consisting of 102 non-athletes and 81 athletes. Three questionnaires were used: VP+2, for measuring personality dimensions of seven-factor model, SH-17, for the assessment of changes in the use of self-handicapping strategies through time and a general biographical questionnaire. A general linear model for repeated measures was used for data analysis. Significant correlation was found between self-handicapping strategies and the number of medals and awards won at international and domestic competitions. The results also showed a positive correlation between self-handicapping strategies and dimensions of Neuroticism and Extraversion and negative with Conscientiousness. Also, a statistically significant difference in the use of self-handicapping strategies was found between athletes and non-athletes, showing that non-athletes express more self-handicapping behaviour. The results indicate that the frequency of selfhandicapping behaviour does not change through time. The effect of gender on self-handicapping is not significant, but there was a statistically significant interaction effect of gender and population on self-handicapping behaviour. It indicates that male non-athletes are more prone to self-handicapping 10 days before an important competition (exam or public speaking for general population, or “game of the season” for sporting population) compared to male athletes. These results, apart from the gender differences, are consistent with the results of previous studies. Limitations of this research and possible directions for future studies were also considered. 

The aim of this study was to establish the genderrelated differences among children 6-6.5 years of age in anthropometric characteristics so as to observe their development and make more appropriate selection for participation in guided and organised physical activities. A battery of 7 anthropometric measurements was used on the representative sample of 175 subjects of both genders from Valjevo (M=45 aged 6 and M=83 aged 6.5; F = 44 aged 6 and F=43 aged 6.5). The multivariate analysis of variance showed the existence of statistically significant differences (p=0.00) in the anthropometric space of the two ages analysed regarding the gender. Through the individual analysis, the differences at age 6 were found in the Upper arm skin fold variable (p=0.03) and the Back-skin fold (p=0.00), whereas with the 6.5-year-old subjects, the differences were found in the Body height variable (p=0.03), Upper arm skin fold (p=0.00) and Back skin fold (p=0.02), both in favour of the boys. It can be assumed that the differences are the result of the endogenous and exogenous factors upon the children's organism in the period of childhood in a smaller urban community of the southwest Serbia. 

The main purpose of our article was to broaden the knowledge of the level of the motor performance of young soccer players in puberty, taking into account their biological age. The object of our research was 18 soccer players in the U 15 category of the soccer club ŠK Slovan Bratislava divided into a subset with accelerated development (n=10) with body height 177,4 ± 5,1 cm, body weight 65,8 ± 7,5 kg and a subset with retarded development (n=8) with body height 170,9 ± 7,3 cm, body weight 63,9 ± 7,7 kg. To assess the motor performance, a set of 3 tests to evaluate speed and speed-coordination (agility) capabilities was applied. The set of tests contained a 10 m run (n=10 - average value of 1.61 s, n=8 - average value of 1.62 s), a 30 m run (n=10 - average value of 4.13 s, n=8 - average value of 4.16 s) and a 5 x 10 m run with a change of direction (n=10 - average value of 11.55 s, n=8 - average value of 11.70 s). Using the Mann-Whitney U test, we did not confirm in our case a statistically significant different level in the motor performance of the monitored sets with regard to the degree of their biological maturity. 

This study presents the results of empirical research conducted with the aim of analyzing differences in the physical activity of children in relation to the socio-economic characteristics of their families. The research was conducted by applying a questionnaire distributed to pupils aged 11-12 years, who live in the city of Novi Sad (the city and the village of Rumenka, Veternik, Kac, Bukovac, Futog). Bearing in mind that the work is a part of a broader research, the authors' attention was focused on the objective, and the evaluation of the respondents on the socioeconomic status of the family, as well as differences in physical activity among boys and girls, and children who live in urban or rural setting. As dominant in this study stands out the finding of the author that the socioeconomic characteristics of families significantly affect the intensity, form and quality of physical activity of children. Since such a finding puts children living in families with low socioeconomic status into a disadvantaged position, the authors believe that with the findings of this and compatible researches it is needed to familiarize with the wider academic community, in order to include other social institutions in the process of affirmation of physical activity as an important lifestyle quality in children and youth. 

The aim of this study was to compare physiological responses during arm and leg aerobic power tests. Ten elite female judokas of the Serbian National Team participated in the study. In addition to the Special Judo Fitness Test (SJFT), maximal oxygen uptake (VO2max) and anaerobic threshold (AT) were determined using an arm crank ergometer and a treadmill. Body fat percentage was estimated by bio-impedance.  The VO2max was only 3 ml∙kg–1∙min–1 higher on the treadmill than in the arm crank (p<0.03), the AT was also higher on the treadmill test (8.6 l∙min1, p=0.005). Nevertheless, the SJFT results were significantly correlated only with the maximal heart rate during the treadmill test (r=0.77, p<0.01 for index; r=-0.73, p<0.02 for total throws). Body fat percentage was correlated with VO2max (r=-0.67, p<0.05) and AT in the arm crank test (r=-0.88, p=0.001). The maximal oxygen uptake was not statistically correlated with the SJFT results in elite female judokas. However, judokas who had higher maximal heart rate during the treadmill test, showed a worse judo-specific capacity on the SJFT. Female judokas with higher body fat seem to have lower VO2max and AT, with statistically significant correlations in the arm crank, and close to significance on the treadmill. On the other hand, arm crank and treadmill tests presented different results concerning aerobic capacity. However, our female judokas interestingly presented similar VO2max results during both aerobic tests, which highlights some judo-specific demands on the upper-body aerobic fitness. 

The purpose of this survey is to establish whether, and in which manner, different sources of stress predict the partner relationship quality, as well as to establish differences concerning the gender, age and job of respondents. Sources of stress are defined as individual, interpersonal and organizational, whereas the quality of partner relationship was tested as a degree of satisfaction with the romantic relationship. The survey was conducted on an adequate sample of 100 respondents involved in a partner relationship, similar in terms of gender and aged 18 to 44. Questionnaires were used to measure the sources of stress and partner relationship quality (Hendrick, 1988). The results indicated that all three sources of stress were significantly connected with the partner relationship quality, also that family-related sources of stress were the only significant predictor (β= 0.286, p<0.01). The greater the family-related sources of stress, the poorer the partnership relation quality. Differences were obtained in assessing the individual factors of stress according to gender and age categories. 

Since previous studies suggest a relationship between motor and cognitive development in children, a research was conducted in order to examine the differences in motor skills of children with different levels of intellectual ability. In a sample of 88 respondents, boys and girls aged 7, an assessment of motor skills was performed by using the battery of seven motor tests and assessment of intellectual abilities by using the test of Raven's Coloured Progressive Matrices. Respondents were divided into three groups according to the results of the test. After analyzing the results of the research it was shown that there were no statistically significant differences in the area of motor abilities of children of different intellectual levels, but there were differences at the univariate level regarding the tests Hand Tapping and Seat-and-Reach. 

The purpose of this research was to establish the expert model of learning and evaluation the most important methodical exercises for teaching short skiing turns in advanced skiing school. Participants were 20 skiing experts from different states. After the experts model was established, experts selected 5 most important methodical exercises for teaching short skiing turns. According to with the goal of the research, total frequency sum of expert choice of the most important methodical exercises has been used (O-observed; E-expected), while the difference between frequencies of expert evaluation has been tested by non-parametric Chi-square test (χ²) and statistic meaning of differences (p). By natural selection, the ranking was made, and selection of the most important methodical exercises for teaching short skiing turns. After data processing, statistical differences were significant in frequencies in which experts choose most important methodical exercises (c2=17.30; p=0.14) while the differences between the values of most important methodical exercises were not established (c2=2.15; p=0.91). Statistical differences based on nationality were not established. Based on the obtained results it can be concluded that the experts in spite of the structural differences and specificity within each ski schools are equally recognized and valued those most important methodical exercises who contain the basic characteristics of effective lessons. This research is a foundation for future modeling which has made a selection of significant errors and exercises for their elimination, and their hierarchical classification.