Background: At present, the portfolio of devices using the bioelectrical impedance (BIA) method is continuously expanding as a result of the wide use of this method in the field as measurements by this method are fast and staff training is simple and reasonably priced. Nonetheless, the problem is that despite using the same method, bioimpedance analyzers can differ in many parameters. They use different electric current frequencies, a different number of electrodes and the electric current may be conducted through different parts of the body.Objective: The main objective of the study is to compare and evaluate the differences of values of the analysis of the body fat of university students measured by BIA analyzers that differ in the applied electric current frequency, number of electrodes and flow of the electric current through the individual body parts.Methods: The research included 125 participants (70 male and 55 female). The measurements were taken by the following analyzers: Tanita 418 MA, InBody 720, InBody R20 and Omron BF 300.Results: The differences in the mean values of the body fat representation between the used analyzers in men ranged from 0.1 to 3.4% and from 0.0 to 2.4 kg, in women from 0.5 to 6.5% and from 0.4 to 3.8 kg in relation to the used analyzer.Conclusions: In men with regular physical activity, the values measured by InBody R20 were statistically and practically different. The analyzer measured higher values that other analyzers. In women, there were statistically and practically significant differences in the values measured by Omron BF 300. This analyzer measured lower values than other analyzers.

Background: Small-sided games belong to specific training where exercise intensity can be manipulated mainly by modifying external factors. To ensure suitable usage of small-sided games in practice, we have to know the variables, which could influence internal responses and external loads. Objective: The purpose of this work is to determine the influence of opponents of different levels on internal response and external load during a 4-a-side soccer game. Methods: Twenty physical education and soccer coaching students (age 22.53 ± 1.02 years; body mass index 20.83 ± 2.13 kg ⋅ m-2; peak heart rate 195.26 ± 6.05 beats ⋅ min-1) participated in the study. Heart rate, distance covered, global rate of perceived exertion, and technical demands (passes, shots, steals, turnovers) were monitored. The participants were divided into two higher level teams and two lower level teams according to experts' perfomance ranking. Results: The results showed significantly lower average heart rate achieved by higher level teams in the 4-a-side game against lower level opponents compared to against higher level teams. Then lower level teams reached significantly higher average heart rate in the 4-a-side game against higher level teams than in mutual lower level team 4-a-side game. We found out significantly higher distance covered by lower level teams in 4-a-side game against higher level teams than in lower level teams mutual 4-a-side game. Conclusions: The results of this study demonstrated that the performance level of opponents influence internal and external load of the players. The higher level of opponents increases the work load of lower level teams.

Background: Developmental coordination disorder (DCD) is a syndrome unexplained by medical condition, which is marked by defects in the development of motor coordination. Children with this impairment are more dependent on visual information to perform movements than their typically developing (TD) peers. Objective: The main aim of the research was to create a checklist for the evaluation of the head and limb movement while walking. After that, based on this tool, to find differences in the movement of various body segments in children at risk of DCD (DCDr) compared to typically developing children under different visual conditions. Methods: A total of 32 children aged 8.7 ± 1.1 years participated in this study. The Movement Assessment Battery for Children - 2nd edition (MABC-2) was used to make a classification of motor competence level of the participants. PLATO goggles were used to make four different visual conditions. All trials were recorded. Based on the video analysis we completed a qualitative checklist. Results: The analysis between the children from the DCDr group and TD children showed significant differences in the head (p = .023) and the arm (p = .005) movements, in body position (p = .002) and total summary score (p = .001). The main effects of visual conditions showed significant differences in all cases; in the head (p = .015), with the arm (p = .006), trunk (p = .009), leg (p = .001) movements, in body position (p = .001) and also in the total summary score (p = .001). The interaction between groups and visual conditions was significant in leg movements (p = .007) and body position (p = .002). Conclusions: This study has shown which movements of body segments are most affected by different visual conditions and how children at risk of DCD are dependent on visual perception.

Background: Training preparation in soccer is thought to improve body composition and performance level, especially the maximal aerobic capacity (VO 2 max). However, an enhancement in performance may be attenuated by the increase of fatigue. Heart rate variability (HRV) as a non-invasive index of autonomic nervous system (ANS) activity has been considered to be a sensitive tool in fatigue assessment. Objective: This study was focused to evaluate the response of ANS activity and morpho-physiological parameters to eight week training preparation. Methods: Study included 12 trained soccer players aged 17.2 ± 1.2 years. Athletes underwent pre- and post-preparation testing that included the ANS activity assessment by spectral analysis of HRV in supine and upright position. Further, body composition was analyzed via electrical bio-impedance method and physiological parameters were assessed during maximal stress tests. ANS activity and subjective feeling of fatigue was assessed continuously within subsequent weeks of preparation. Results: No significant differences in all HRV variables within weeks were found. Pre vs. post analyses revealed a significant (p < .05) increase in body weight, fat free mass, body mass index, and peak power. A significant decline in mean maximal heart rate (HR) and resting HR at standing was identified at the end of preparation. Since no significant changes between pre- post-preparation in the mean VO 2 max occurred, the positive correlation between the individual change in VO 2 max and the vagally related HRV [supine LnHF (r = .78), Ln rMSSD (r = .63), and the standing LnHF (r = .73, p < .05)] was found. Conclusions: This study showed that an 8 week training program modified particularly fat free mass and short-term endurance, whereas both the autonomic cardiac regulation and the feeling of fatigue remained almost unaffected. Standing position seems to be more sensitive in terms of the HR response in relation to fatigue perception than supine.

Background: Effective tourism management in the field of sports tourism requires an understanding of differences in socioeconomic characteristics both within and between different market segments. Objective: In the broad tourism market demographic characteristics have been extensively analyzed for differences in destination choices, however little is known about demographic factors affecting sport tourists' decisions. Methods: A sample of Slovenian sports tourists was analyzed using data from a comprehensive survey of local and outbound tourist activity conducted by the Statistical Office of the Republic of Slovenia in 2008. After data weighting the information for 353,783 sports related trips were available for analysis. The research model adopted suggests that four socio-demographic characteristics (gender, age, level of education and income) significantly affect a tourist's choice of sports related travel either locally within Slovenia or to a foreign country. Furthermore the destination (local or foreign) has an influence on the choice of the type of accommodation selected and the tourist's total expenditure for the trip. For testing the first part of our model (the socio-demographic characteristics effects) a linear regression was used, and for the final part of the model (the selection of accommodation type and travel expenditure) t-test were applied. Results: The result shows the standardized β regression coefficients are all statistically significant at the .001 level for the tested socio-demographic characteristics and also the overall regression model was statistically significant at .001 level. Conclusions: With these results the study confirmed that all the selected socio-demographic characteristics have a significant influence on the sport-active tourist when choosing between a domestic and foreign tourism destination which in turn affect the type of accommodation chosen and the level of expenditure while travelling.

Background: Alpine skiing is a sport with a very complex structure and a high variability of movements. The stage of preliminary sport preparation in alpine skiing is important in a relation to the need of creating physical demands which enable an optimal and continuous growth of the performance. Inline skating is a very good substitution with a similar loading of lower limbs and muscle involvement as in skiing because inline skates offer a sense of sliding; stance and edge change and the technique for making curves are very similar. Objective: The main purpose of this paper was to assess the influence of a 9 week specialized training program on the changes in the level of balance abilities development of 8-10 year old children in alpine skiing. This specialized training program consisted of exercises on inline skates and from balance exercises on non-specific equipment. Methods: This research was organized by using a single-factor parallel experiment with two groups. Specialized motion program was 9 weeks long and it was used in the experimental group during the preparatory period in the stage of preliminary sport preparation. The experimental group completed a total of 90&#8239;minutes of specialized training per week, of which 60&#8239;minutes were special exercises on inline skates and 30&#8239;minutes were exercises for development of balance skills on non-specific tools. The control group underwent generally focused training. To determinate the level of balance we used tests of both static and dynamic balance. Results: Based on the tests results we found statistically significant improvement of the performance in all of the tests for balance abilities in the experimental group due to the specialized training program. The control group showed no significant differences during generally focused training process on the development of physical abilities. Conclusions: A 9 week training program consisting of 3 training sessions per week was long enough to have a positive influence on the development of balance abilities of children of school age in alpine skiing. We included specific ski-motions into the nonspecific movements using methods for the development of balance abilities in the duration of 30&#8239;minutes at the beginning of each training session.

BACKGROUND:In gymnastics judging, evaluation of routines in their execution is based on form and technique displayed during the performance.A vaulting performance takes a short time and is affected by the quantity of biomechanical variables.The significant relationships between the vault score and specific aspects of the gymnast's vault should motivate coaches to monitor these variables as a part of training or routine testing.OBJECTIVE: The purpose of the study was to determine the biomechanical variables that are related to a successful performance of Lou Yun vaults performed by top level male gymnasts during the World Cup competition.METHODS: Ten top-level male gymnasts participated in this study.For the 3D kinematic analysis, two digital camcorders with a frame rate of 50 Hz were used.The data was digitized by Simi Motion software.The Hay and Reid method (1988) was used to identify the biomechanical variables that determine the linear motions of the Lou Yun vaults.A correlation analysis was used to establish the relationship between the biomechanical variables and the judges' scores.The level of statistical significance was determined at the value of p < .05.RESULTS: Six out of 24 examined variables showed significant correlations with the scores.A significant correlation was found in the maximum height of the body centre of mass in the second flight phase (r = .68),in the height of centre of mass at mat touchdown (r = .75),in the relative height from table take-off to mat touchdown (r = -.85), in the duration of the table contact phase (r = -.71), in the duration of the second flight phase (r = .62)and in the vertical velocity of body centre of mass at table take-off (r = .70). CONCLUSIONS:The results of the study suggest that a successful execution of Lou Yun vaults and the achievement of a higher score required: to minimize duration of table support phase; to maximize the vertical velocity in the table take-off phase; to maximize the amplitude of the second flight phase, which is determined by the duration of the second flight phase, by the maximum height of the body centre of mass in the second flight phase, and by the distance from the vaulting table during landing; and to maximize the height of the body centre of mass in the mat contact phase.

BACKGROUND:The issues of the age effect (the theory of the age influence) have been shown in sport sciences since the 1980s.The theory of age effect works on the assumption that athletes born in the beginning of a calendar year are, particularly in children's and junior age, more successful than athletes born in the end of the year.This fact has been proved by a number of research studies, mainly in ice hockey, soccer, and tennis but also in other sports.OBJECTIVE: The submitted contribution is aimed at verifying of the age effect in junior tennis.The research objective was to find out the distribution of birth date frequencies in a population of tennis players' in individual months, quarters, and half-years in the observed period 2007-2011 and to check the significance of differences.METHODS: The research was conducted on male tennis players aged 13-14 (N = 239), participants of the World Junior Tennis Finals.From the methodological point of view, it was an intentional selection.The birth dates of individual tennis players were taken from official materials of the ITF, the research data were processed using Microsoft Excel.The personal data were processed with the approval of players and the hosting organization (ITF).RESULTS: Testing of the hypothesis on the significance of differences in the distribution of frequencies between individual quarters (Q1-Q4) has proved statistically relevant differences between Q1 and Q3, Q1 and Q4, Q2 and Q3, and Q2 and Q4; a statistically relevant difference has been also found in the distribution of frequencies between the first and second half of the year.On the basis of the results of the presented research, the age effect in the studied population of junior male tennis players can be regarded as significant.CONCLUSIONS: The results of the analysis of the research data confirm the conclusions of similar studies in other sports and prove that in the population of elite junior players, participants of WJTF 2007-2011, there is a pronounced dominance of players born in the first and second quarters, i.e. in the first half-year.The mentioned conclusions show the necessity of reflecting the age effect in sports practice as it can influence sports performance, especially at the junior level.

Background: The Movement Assessment Battery for Children (MABC) is one of the most frequently used instruments for motor assessment in children. The norms for motor performance in the tests of the revised second version of the battery (MABC-2) were established from the study with the representative sample of the United Kingdom (UK) population of children. Assessment of motor function development derived from results of the motor tests in children can be affected by some social and cultural factors. Objective: The aim of the study was to evaluate the suitability of the original norms of the MABC-2 for use in the Czech Republic. Methods: The results of the MABC-2 in the representative sample of Czech children aged 7-10 years (n = 487) were compared to test performance of the UK normative sample of children (n = 333) published in the MABC-2 Examiner's Manual using the Cohen's effect size and the z-test. Results: Non-significant differences were found in gross motor coordination performance between Czech and UK samples. The Czech girls achieved significantly higher scores in the manual dexterity as compared to the UK sample. Most age groups of the Czech sample showed a significantly higher performance in the balance tests of the MABC-2 than the UK sample. Conclusions: The study suggested that the original norms of the MABC-2 can be valid for motor assessment only in the 7-8 year-old Czech boys. Some adjustments of the UK norms for the manual dexterity and balance tests are needed to use this test battery in clinical, psychological and educational practice in the Czech Republic.

Background: An increase of leisure time and vigorous physical activity (PA) in girls can be supported by their regular participation in organised PA, as it brings numerous health benefits and is an important part of healthy lifestyle. Objective: This study aimed to examine whether there are differences in physical activity and inactivity structure and levels in girls who do not participate in any organised PA and girls who regularly participate in physical education or training classes. Methods: The sample comprised 497 girls (age 17.94 ± 0.52 years) from Poland participating never (group 1), or once (group 2), twice (group 3), and three or four times (group 4) a week in any organised PA. The Polish version of the International Physical Activity Questionnaire (IPAQ), accelerometer ActiGraph GT1M and activity and inactivity logs were used to assess the level and structure of physical activity and inactivity. Results: Girls participating in organised PA three or more times a week showed significantly the highest values of steps/day, moderate and vigorous PA, and leisure time PA, but also inactivity in comparison to girls without participation in organised PA. Conclusions: This study provides the evidence supporting the positive link between a number/week participation in organised PA and PA level. However, the findings from this study also advocate the need of increasing PA and reducing inactivity in girls in school or after-school periods, regardless of the participation in organised PA.