Montenegrin Journal of Sports Science and Medicine

5-11

Authors: Seyed Morteza Tayebi, Ali Akbar Mahmoudi, Elaheh Shirazi, Maedeh Sangi

The present study was conducted to investigate the acute responses of some iron indices of young elite wrestlers to three types of aerobic, anaerobic, and wrestling exercises. A total of 24 elite volunteer wrestlers were randomly categorized into three groups (n=8) aerobic, anaerobic, and routine wrestling exercises. The exercises were conducted during three non-consecutive sessions within one week. The aerobic exercises included 35 min of continuous running with 130 beats per minute (BPM) on a treadmill; the anaerobic exercises included 15 min circuit movements and 15 min rest with 160 BPM, and the wrestling training included routine wrestling exercises. Blood sampling was done in the first and third sessions in order to study the acute responses which included four stages of 1 h before, immediately, 3 h, and finally 24 h after exercises. The study of the acute response to the first session showed that the type of exercise had no effect on serum iron (p=0.57). Furthermore, the serum ferritin (p=0.012) and TIBC (p=0.006) affected was affected by type of exercise. The study of the acute response to the second session showed that the type of exercise had no effect on serum ferritin (p=0.731) and TIBC (p=0.231), rather the serum iron was affected by the type of exercise (p=0.01). Conclusively, the study of acute response showed that wrestling exercises led to a decline in iron stores during exercise and reduced total iron binding capacity during a 24-h recovery period. The study of acute exercise after a short adaptation period showed that despite the fact that serum iron had no change in anaerobic and wrestling exercises over the passage of time, it changed during aerobic exercise and 24-h recovery periods. Furthermore, the progress of iron deficiency was only observed in the first stage which prevented its progress to the next stage.

29-35

Authors: Sakir Serbes, Cevdet Cengiz, Murvet Sivri, Tugce Filiz

The purpose of this study is to examine public and private middle school students’ levels of Health-Related Fitness Knowledge (HRFK) according to school type, gender, and grade. A cross-sectional survey method was applied in the research. A total of 334 public middle school students (nfemale =154 and nmale = 180) and 386 private middle school students (nfemale =187 and nmale = 199) participated in the survey. The data collection instrument was developed by Hunuk and Ince (2010) based on the “Superkids-Superfit Knowledge” study (Mott, Virgilio, Warren and Berenson, 1991). The data collected was analysed using the following descriptive and non-parametric tests: the Pearson chi-square, Mann-Whitney U-test, and Kruskal-Wallis H-test. Findings indicated a significant difference according to school type and age group (p<.05), but a non-significant difference according to gender and HRFK test result. Results improved year to year except among 7th graders. In other words, private middle school students’ HRFK results were higher than those of public middle school students; grade level was also linked to HRFK, but gender was not. These results suggest that physical education curriculums should be developed with reference to HRFK objectives. Another recommendation would be that HRFK tools be customized by grade level in the Turkish context.

45-48

Authors: Karel Hulka, Radim Weisser

Small-sided games are a specific form of training in which exercise intensity can be manipulated mainly by modifying external factors. The aim of this study was to determine the influence of a number of players during small sided futsal games on metabolic responses and distance covered at elite senior futsal players. Fifteen top level Czech futsal players (males, aged 26.81±5.30; body height = 176.10±4.34 cm; body weight = 71.31±5.30 kg, and peak heart rate=191.23±5.4 beats•min-1) participated in the study. Heart rate, blood lactate concentrations, distance covered, and rate of perceived exertion were monitored during small-sided futsal games. We found significant differences between blood lactate concentration values and perceived exertion; it was significantly higher during 3vs3 and 4vs4 small-sided games than during 6vs6 games. When we compared the distance covered by players, we found significantly higher distance covered during 4vs4 than in 6vs6 games. The results of this study demonstrated that the small-sided games 3vs3 and 4vs4 were valuable tools to develop specific futsal fitness. As the most intensive, the 4-a-side game was found.

57-64

Authors: Marta Hurst, Manuel Loureiro, Beatriz Valongo, Lorenzo Laporta, Pantelis Nikolaidis, José Afonso

This work analysed team sports as complex systems in which behavioural variables need to be taken into consideration when studying performance. Within this understanding, the use of Social Network Analysis constitutes a useful research path. As such, this research analysed two of the least studied game complexes: attack coverage and freeball and downball, in eight matches from the first Group Stage of the Women’s World Grand Prix 2015, comprising a total of 1,264 rallies. Eigenvector centrality values were calculated, with each behavioural variable counted as a node and their connections as edges. The results showed that playing in off-system is central in both complexes, although more so in attack coverage than in freeball and downball situations. Results also showed that although freeing a higher number of players for attack action is potentially advantageous, such action would become a disadvantage when faced with an effective blocking action and the sudden need for effective attack coverage. Overall, this study showed that volleyball coaches should take off-system game moments into stronger consideration and devise a strategy of play that will turn off-system play into an advantage.

73-79

Authors: Bülent Okan Miçooğulları

The aim of the present study was to examine the psychometric properties of the Test of Performance Strategies (TOPS; Thomas et al., 1999) on the Turkish population. The TOPS was designed to assess eight psychological skills and strategies used by athletes in competition (activation, automaticity, emotional control, goal-setting, imagery, relaxation, self-talk, and negative thinking) and the same strategies, except negative thinking is replaced by attentional control used in training. The sample of the study included athletes who were training and competing in a wide variety of sports across a broad range of performance standards. The final sample consisted of 433 males (mean ± s: age 22.47 ± 5.30 years) and 187 females (mean ± s: age 20.97 ± 4.78 years), 620 athletes in total (mean ± s: age 21.25 ± 4.87 years) who voluntarily participated; TOPS was administered to all participants. Afterward, Confirmatory Factor Analysis (CFA) was conducted by Analysis Moments of Structures (AMOS) 18. Comparative fit index (CFI), non-normed fit index (NNFI) and root mean square error of approximation (RMSEA) were used to verify whether the model fit the data. Goodness-of-fit statistics were CFI= .91, NNFI= .92 and RMSEA= .056. These values showed that the tested model is coherent at a satisfactory level. Moreover, results of confirmatory factor analyses revealed that a total of four items (two items from competition and two from practice) within the subscale of automaticity have been removed. The 28 items within the remaining seven subscales have been validated. In conclusion, Turkish version of TOPS is a valid and reliable instrument to assess the psychological skills and strategies used by athletes in competition and practices.

5-12

Authors: Mandic, Sandra; Wilson, Hamish; Clark-Grill, Monika; O’Neill, Diana

The effectiveness of physicians in providing advice to patients about physical activity (PA) is influenced by their own understanding of the links between PA and health, as well as by their own PA habits. This study involved pre-clinical medical students in New Zealand, examining their baseline knowledge, skills, and attitudes towards advising patients about PA, as well as eliciting their personal exercise habits. A total of 234 students (age 20.9±2.9 years; 46% males; participation rate: 99%) completed a paper questionnaire assessing their awareness of current PA guidelines, the benefits of PA, their attitudes toward PA advising, perceived competence and importance of PA-advising skills, and personal PA habits. Data were analysed using descriptive statistics. Most students were aware of the benefits of PA and were regularly active. Students perceived PA advising as a high priority in general practice (79%) but only 37% felt confident in their ability to provide PA advice. At this point in their training, students considered PA advice to be important (4.7±0.8 out of 6), yet perceived themselves to be only moderately competent in providing patient-oriented exercise prescriptions (3.1±0.8 out of 6). However, students who had regular exercise felt more confident in providing PA advice (3.0±0.9 vs. 3.3±0.9, p=0.009). In conclusion, medical students were generally active and had a good understanding of the links between PA and health, but were lacking skills for PA advising. Competence and skills in PA counselling need to be further developed within clinical training as part of an overall curriculum strategy.

19-26

Authors: Šiljeg, Klara; Sindik, Joško; Leko, Goran

Swimming tests are used in every training cycle and seasons with purpose of estimating swimming performance and evaluate certain training types. The focus of this study is an attempt to distinguish between the potential short-distance and longer-distance swimmers, as well as the swimmers who could have desirable profiles for particular swimming styles. For this purpose, several aims are given: () to determine the latent dimensions of the performances in swimming tests, conducted on various distances and performed using different swimming styles; 2) to determine the correlations between speeds on various distances using different swimming styles; 3) to determine the differences in various distance speeds at the same swimmers ; 4) to determine the profiles of swimmers, based on the various distance speeds (4). Male swimmers (N=68), aged 14 to 16 from five Zagreb clubs were tested. Four swimming tests were used to measure speed (25-m freestyle, backstroke, breaststroke, butterfly), five swimming tests measured speed endurance (50-m freestyle, 100-m freestyle, backstroke, breaststroke, butterfly), while only one test measured endurance (800-m freestyle). The results revealed two interpretable and highly reliable latent dimensions of swimming tests. Factor analysis of the scores in swimming tests differentiated the variables of swimming tests that describe breaststrokes and other strokes. Most of the scores in the swimming tests are positively correlated (in range 0.25–0.85), while no differences in various distance speeds among the same swimmers are found. The results indicate the importance of using swimming tests, especially in breaststrokes styles, because of their specific motor structure.

35-41

Authors: Loureiro, Manuel; Hurst, Marta; Valongo, Beatriz; Nikolaidis, Pantelis; Laporta, Lorenzo; Afonso, José

A deeper understanding of the factors behind performance and their interactions is essential to promote better training practices. Notwithstanding, the focus often relies on the outcomes of players’ actions (e.g., efficacy rates), whereas the nature and variations of particular classes of actions remain largely unexplored. Our purpose was to conduct a systemic analysis of categorical game variables and their interactions using Social Network Analysis. Game actions were counted as nodes and their interactions as edges. Eigenvector centrality values were calculated for each node. Eight matches of the Men’s World Cup 2015 were analysed, composing a total of 27 sets (1,209 rallies). Four game complexes were considered: Complex 0 (Serve), Complex I (Side-out), Complex II (Side-out transition) and Complex III (Transition). Results showed that teams frequently play in-system when in Complex I (i.e. under ideal conditions), but present reduced variation with regard to attack zones and tempos, whereas in Complex II teams most often play out-of-system. Based on these findings, it was concluded that practicing with non-ideal conditions is paramount for good performance in Complex II. Furthermore, most literature combines Complex II and Complex III as a single unit (counter-attack); however, our results reinforce the notion that these two game complexes differ and should be analysed separately.

49-56

Authors: Luptáková, Gabriela; Antala, Branislav

Collaborative learning has been shown to be a useful tool for improving several social skills in students; however, it is very difficult to set up the initial conditions that guarantee its effectiveness. Since group projects are made for students and, most importantly, by students, we should not forget to take their opinions based on previous experience into consideration, which might increase the efficiency of their own learning. Therefore, the aim of the study was to investigate what secondary school students learn from and think about group projects in Physical Education. A total of 94 secondary school students (46 girls and 48 boys) participated in the study carried out in the 2015/2016 school year. The participants were given the assignment to create a video exercise, which they were working on in small groups in PE. A questionnaire was designed to investigate students’ learning outcomes, participation, evaluation, and attitudes towards the project. Differences for selected categorical variables were determined using the Chi-square test. The majority of the students reported improvement in selected social skills and better relationships with their teammates. In addition, several significant differences in students’ opinions with respect to age and gender were found.

67-74

Authors: Kozinc, Žiga; Sarabon, Nejc

Runners are particularly prone to developing overuse injuries. The most common running-related injuries include medial tibial stress syndrome, Achilles tendinopathy, plantar fasciitis, patellar tendinopathy, iliotibial band syndrome, tibial stress fractures, and patellofemoral pain syndrome. Two of the most significant risk factors appear to be injury history and weekly distance. Several trials have successfully identified biomechanical risk factors for specific injuries, with increased ground reaction forces, excessive foot pronation, hip internal rotation and hip adduction during stance phase being mentioned most often. However, evidence on interventions for lowering injury risk is limited, especially regarding exercise-based interventions. Biofeedback training for lowering ground reaction forces is one of the few methods proven to be effective. It seems that the best way to approach running injury prevention is through individualized treatment. Each athlete should be assessed separately and scanned for risk factors, which should be then addressed with specific exercises. This review provides an overview of most common running-related injuries, with a particular focus on risk factors, and emphasizes the problems encountered in preventing running-related injuries.

5-10

Authors: Marko D. Stojanovic, Julio Calleja-Gonzalez, Mladen Mikic, Dejan M. Madic, Patrik Drid, Igor Vuckovic, and Sergej M. Ostojic

The purpose of the present study was to evaluate the specificity of a 20-m shuttle run test (SRT) as a measure of maximal oxygen consumption (VO2max) in young well-trained basketball players. Thirty-four volunteers (mean ± SD; age 15.74 ± 1.23 years, height 187.61 ± 7.95 cm, body mass 74.09 ± 11.61 kg; training experience 6.30 ± 2.15 years) participated in the study. The 20-m shuttle run test was performed wearing a portable gas analyzer (K4b2, Cosmed) to measure VO2max during the test. SRT-derived VO2max underestimated directly measured values (48.91 ± 4,11 vs 55.45 ± 4.98). Mean bias was 6.54 ± 3.89 ml kg-1 min-1 (95% CI- 5.18 to 7.90 ml kg-1 min-1 ). Typical error of the estimate was 3.85 ml/kg/min-1 (95% CI- 3.10 to 5.10 ml kg-1 min-1 ; ES= 0,77). There was a moderate correlation between VO2max directly measured and estimated by SRT (r= 0.65; 95% CI- 0.40 to 0.81, power = 0.84, p < 0.01). Although very popular among coaches, it seems that SRT is not an appropriate field test to measure maximal oxygen consumption in young well-trained basketball players.

17-23

Authors: Hamid Arazi, Abbas Asadi, and Jabar Chegini

Although a few studies examined the effects of plyometric exercise on cardiovascular responses and symptoms of muscle damage, the data about the different types of plyometric exercise such as eccentric-based vs. concentric-based exercise is scarce. The purpose of the present investigation was to compare the effects of eccentric and concentric-based plyometric exercises on post-exercise systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR) and symptoms of muscle damage. Nineteen healthy men volunteered to participate in this study and were randomly assigned to two groups: Depth jump group (DJG; N=9; Eccentric) and Box jump group (BJG; N=10; Concentric). After plyometric exercise SBP, DBP and HR were measured every 10 min for a period of 90 min post-exercise. Also, muscle soreness, vertical jump and 10-m sprint were assessed at 24, 48, and 72 h post-exercise. There were no significant changes in SBP and DBP, and no significant differences between groups in SBP and DBP, whereas the DJG showed greater increases in HR when compared with BJG. Both the groups indicated significant differences in muscle soreness, vertical jump and 10-m sprint at 24, 48 and 72 h post-exercise without significant differences between them. The findings of this study demonstrated that there were no differences in SBP and DBP between groups and both groups showed increases in symptoms of muscle damage following plyometric exercise.

33-38

Authors: Dario Novak, Ivana Milanovic, Snezana Radisavljevic Janic, Lovro Štefan, and Tomislav Kristicevic

Social capital has been shown as a positive asset for improving overall health in children and youth. Thus, the purpose of the present study was to determine the associations between family, neighborhood and school social capital with self-rated health among Serbian high-school students. This cross-sectional study on 1220 high-school students (539 males and 681 females) was carried out in the school year 2015/2016. Main outcome was defined as self-rated health, measured by one question: "How would you rate your health?" with five possible answers: (1) very poor; (2) poor, (3) fair, (4) good and (5) excellent. We binarised the outcome, where answers "very poor", "poor" and "fair" represented "poor health" and "good" and "excellent" "good health". Multiple logistic regression was used to determine the associations between social capital domains and self-rated health. Adjusted by gender, body-mass index, self-perceived socioeconomic status, psychological distress and physical activity, good self-rated health was positively associated only with high family social capital (OR 2.29; 95% CI 1.62 to 3.24). When all the social capital variables were entered simultaneously, self-rated health remained associated with family social capital (OR 2.28; 95% CI 1.61 to 3.24). Family social capital was the only domain strongly associated with self-rated health. Since neighborhood and school social capital represent key support and empathy for children and youth, neighborhood and school-based strategies and policies should be implemented within the system to increase overall physical and mental health.

5-9

Authors: Nejc Sarabon, Karmen Hirsch, Ziva Majcen

The aim of this study was to investigate the effects of unilateral hip abductor fatigue on body sway in ipsilateral and contralateral single legged stance. Acute effects repeated measurements design. Thirteen recreationally active middle aged subjects participated in the study. All subjects performed two 30s repetitions of unilateral stance on each leg. The first measurement was obtained at baseline, the second followed a control protocol of active hip abduction in supine position without additional resistance and the third measurement was conducted as aforementioned second protocol, only against elastic resistance. The center of pressure (CoP) movement characteristics during single-leg quiet stance (i.e. body sway) were analyzed by calculating the average velocity of the CoP movement and direction specific (medial-lateral and anterior-posterior) average velocity, amplitude and frequency of the CoP mo¬ve¬ment. The results of this study indicate that fatigue significantly affected body sway in both single leg stances (p < 0.05) and in both medial-lateral and anterior-posterior direction. However, medial-lateral body sway tended to be increased more than in anterior-posterior direction. A significant crossover effect of increased body sway on the opposing limb suggests that in addition to local muscle fatigue, changes in central nervous system might have taken place. The above findings are of greater importance as they allow a more thorough insight into the mechanisms responsible for controlling balance that could have an important implication on designing training programs.

17-28

Authors: Joško Sindik, Zlatka Kozjak Mikić, Lucija Dodigović, Sanda Čorak

Goals of this research were to determine the correlations among the dimensions of relevant factors about engagement of women in sports, as well as to determine the differences in the dimensions of relevant factors about engagement of women in sports, according to several independent variables: type of sport, educational level, marital status and place of living. A total of 342 female athletes and other sport practitioners are examined, with the average age of 31.53±13.92 years (M±SD) from several Croatian sport federations: judo, badminton, gymnastics, bowling, acrobatic rock’n roll, handball, sport fishing, Association of the deaf athletes, archery, chess and basketball. The results revealed that according to the type of sport, the differences are statistically significant for: negative environment, relaxation/fun and ambition/self-esteem motives; environmental, obligation and financial/traffic/rules barriers; indirect strategies and already present initiatives for including women in sports. According to the education level, the differences are statistically significant for: positive personal, negative environmental motives and ambition/self-esteem motives; obligations as the barriers; organization out-of-sport commitments and specific strategies for media. The differences in the marital status of participants are statistically significant for the variables: positive personal, negative environmental and ambition/self-esteem motives; environmental and obligation barriers; organization of out-of-sport commitments. At last, only two statistically significant differences are found according to the place of living: for indirect strategies for including women in sports and for the programs created only for women. The results provide the platform for developing programs and strategies for retaining and engaging women in particular sports in Croatia.

35-46

Authors: Miguel Silva, Rui Marcelino, Daniel Lacerda, Paulo Vicente João

The present article aims to review the available literature on match analysis in adult male Volleyball. Specific key words "performance analysis", "match analysis", "game analysis", "notational analysis", "tactical analysis", "technical analysis", "outcome" and "skills" were used to search relevant databases (PubMed, Web of Science, SportDiscus, Academic Search Complete and the International Journal of Performance Analysis in Sport). The research was conducted according to PRISMA (Preferred Reporting Items for Systematic reviews and Meta analyses) guidelines. Of 3407 studies initially identified, only 34 were fully reviewed, and their outcome measures extracted and analyzed. Studies that fit all inclusion criteria were organized into two levels of analysis, according to their research design (comparative or predictive) and depending on the type of variables analyzed (skills and their relationship with success, play position and match phase). Results show that from a methodological point of view, comparative studies where currently complemented with some predictive studies. This predictive approach emerged with the aim to identify the relationship between variables, considering their possible interactions and consequently its effect on team performance, contributing to a better understanding of Volleyball game performance through match analysis. Taking into account the limitations of the reviewed studies, future research should provide comprehensive operational definitions for the studied variables, using more recent samples, and consider integrating the player positions and match phase contexts into the analysis of Volleyball.

5 - 10

Authors: Michael Chia, Bokai Chen, Haresh Suppiah

Excessive sitting is detrimentally associated with major lifestyle diseases. Attempts at intervening the prolonged sitting time at work offer possibilities for a healthier lifestyle. The aim of the study was to evaluate the impact of using a seat-cycle (S-C) compared to the office-chair (O-C) in reducing prolonged sitting in the office. Twenty-one (mean age = 48±12.4 years) office workers (10 men and 11 women; mean BMI = 24.1±4.6 kg/m͘͘²) volunteered to participate in an 11-week crossover design study. Participants were randomly assigned into two groups- each started with different conditions: the office-chair (O-C) or the seat-cycle (S-C) intervention for 4 weeks with a 2-week ‘washout’ period in-between before switching over. Self-reported sleep quality, lower back pain, daytime sleepiness and several anthropometric measurements were obtained under the two conditions. Participants spent on average 5.79±1.51 hrs sitting in the office, and used the seat-cycle for an average of 22.8 minutes daily at work. Significant improvements (p<0.05) were noted in a pre-to-post setting for resting systolic blood pressure (124.9±12.57 mmHg vs 120.5±13.56 mmHg); sleepiness ratings between 1300–1400 hrs (1.91±0.71 vs 1.56±0.57); lower back pain score (0.95±1.02 vs 0.57±0.68) and sleep quality (4.81±2.16 vs 3.38±2.04) after the S-C intervention. The use of the S-C provides desk-bound workers a potential way to interrupt prolonged sitting at work and further research is recommended to support such interventions at the workplace.

17 - 28

Authors: Joško Sindik, Anđelko Botica, Matej Fiškuš

Sport psychologist needs to understand how psychological factors affect athletic performance of an individual, considering individual differences among athletes. Each specific problem in working with athletes must be considered depending on complex factors: the type (specificity) of sport; characteristics of the activity (the training or competition); stages of athletes’ sports development; gender and age differences, etc. Although there are numerous psychological instruments, which assess psychological characteristics of athletes, it is important to select instruments adjusted to athletes, working style of sports psychologist, available time and other constraints. Here, we have formulated a preliminary version of our own battery of questionnaires, named Multi¬di¬men¬sional Inventory of Sport Excellence (MUSI), selecting the items for following psychological characteristics: energizing, main¬tain¬ing attention, directing attention, wide internal / external attention and narrow internal / external attention. In this phase of the stu¬dy, participants were stratified only by gender. Sample of 248 participants was examined, of which 103 male athletes (age 24.52 ± 11.80 years) and 145 female athletes (age 16.61 ± 6.69 years), from the Croatian sports clubs, competing in 16 different sports (archery, football, handball, bocce, bowling, cycling, karate, rowing, tennis, volleyball, basketball, synchronized swimming, tri¬a¬t¬h¬lon, table tennis, chess, badminton). Data were collected from March to June 2014 in Rijeka, during the trainings in sports clubs. Results of Principal Component Analysis and the reliabilities type internal consistency showed that each of sub-question¬na¬ires from battery MUSI have satisfactory reliability and construct validity, giving positive guidance for future adaptation of the que¬stion¬naire to specific subpopulations of athletes.

35 - 36

Authors: Sergej M. Ostojic

Nucleotides are group of natural biomonomeric molecules and novel dietary supplements with performance-enhancing attributes. However, their mechanisms of action and target biological structures are poorly understood and identified. This short paper overviews the possible role of mitochondria during the utilization of nucleotides for exercise performance. Mitochondria-related effects of nucleotides have been identified, along with obstacles for dietary nucleotides delivery to the organelle.