Damir Sekulic

Gender-specific Influences of Balance, Speed, and Power on Agility Performance

Abstract Sekulic, D, Spasic, M, Mirkov, D, Cavar, M and Sattler, T. Gender-specific influences of balance, speed, and power on agility performance. J Strength Cond Res 27(3): 802–811, 2013—The quick change of direction (i.e., agility) is an important athletic ability in numerous sports. Because of the diverse and therefore hardly predictable manifestations of agility in sports, studies noted that the improvement in speed, power, and balance should result in an improvement of agility. However, there is evident lack of data regarding the influence of potential predictors on different agility manifestations. The aim of this study was to determine the gender-specific influence of speed, power, and balance on different agility tests. A total of 32 college-aged male athletes and 31 college-aged female athletes (age 20.02 ± 1.89 years) participated in this study. The subjects were mostly involved in team sports (soccer, team handball, basketball, and volleyball; 80% of men, and 75% of women), martial arts, gymnastics, and dance. Anthropometric variables consisted of body height, body weight, and the body mass index. Five agility tests were used: a t-test (T-TEST), zig-zag test, 20-yard shuttle test, agility test with a 180-degree turn, and forward-backward running agility test (FWDBWD). Other tests included 1 jumping ability power test (squat jump, SQJ), 2 balance tests to determine the overall stability index and an overall limit of stability score (both measured by Biodex Balance System), and 2 running speed tests using a straight sprint for 10 and 20 m (S10 and S20, respectively). A reliability analysis showed that all the agility tests were reliable. Multiple regression and correlation analysis found speed and power (among women), and balance (among men), as most significant predictors of agility. The highest Pearsons correlation in both genders is found between the results of the FWDBWD and S10M tests (0.77 and 0.81 for men and women, respectively; p < 0.05). Power, measured using the SQJ, is significantly (p < 0.05) related to FWDBWD and T-TEST results but only for women (−0.44; −0.41). The balance measures were significantly related to the agility performance for men but not for women. In addition to demonstrating a known relationship between speed and agility in both genders, and a small but statistically significant relationship between power and agility in women, these results indicate that balance should be considered as a potential predictor of agility in trained adult men.

Vertical jumping tests in volleyball: reliability, validity, and playing-position specifics.

Abstract Sattler, T, Sekulic, D, Hadzic, V, Uljevic, O, and Dervisevic, E. Vertical jumping tests in volleyball: reliability, validity, and playing-position specifics. J Strength Cond Res 26(6): 1532–1538, 2012—Vertical jumping is known to be important in volleyball, and jumping performance tests are frequently studied for their reliability and validity. However, most studies concerning jumping in volleyball have dealt with standard rather than sport-specific jumping procedures and tests. The aims of this study, therefore, were (a) to determine the reliability and factorial validity of 2 volleyball-specific jumping tests, the block jump (BJ) test and the attack jump (AJ) test, relative to 2 frequently used and systematically validated jumping tests, the countermovement jump test and the squat jump test and (b) to establish volleyball position–specific differences in the jumping tests and simple anthropometric indices (body height [BH], body weight, and body mass index [BMI]). The BJ was performed from a defensive volleyball position, with the hands positioned in front of the chest. During an AJ, the players used a 2- to 3-step approach and performed a drop jump with an arm swing followed by a quick vertical jump. A total of 95 high-level volleyball players (all men) participated in this study. The reliability of the jumping tests ranged from 0.97 to 0.99 for Cronbachs alpha coefficients, from 0.93 to 0.97 for interitem correlation coefficients and from 2.1 to 2.8 for coefficients of variation. The highest reliability was found for the specific jumping tests. The factor analysis extracted one significant component, and all of the tests were highly intercorrelated. The analysis of variance with post hoc analysis showed significant differences between 5 playing positions in some of the jumping tests. In general, receivers had a greater jumping capacity, followed by libero players. The differences in jumping capacities should be emphasized vis-a-vis differences in the anthropometric measures of players, where middle hitters had higher BH and body weight, followed by opposite hitters and receivers, with no differences in the BMI between positions.

Substance abuse prevalence and its relation to scholastic achievement and sport factors: An analysis among adolescents of the Herzegovina-Neretva Canton in Bosnia and Herzegovina

BackgroundSubstance abuse among adolescents is a major public health and social problem. However, studies rarely investigate the relationships between substance abuse, educational achievement and sport factors. Substance abuse is an even more significant problem in societies that have experienced trauma, such as Bosnia and Herzegovina, which have had recent wars. The aims of this study were to investigate substance abuse among adolescents in Bosnia and Herzegovina and to study the potential gender-specific relationships between a) sport factors (physical activity/exercise/athletic participation) and substance abuse and b) scholastic achievement and substance abuse.MethodsOur sample consisted of 1,032 adolescents who were 17 to 18 years old (435 boys and 597 girls) and who were in the final grade of high school. These subjects were randomly selected from the territory of Herzegovina-Neretva Canton of Bosnia and Herzegovina. Retrospective testing was performed using an extensive self-administered questionnaire. The questionnaire included questions involving topics such as sociodemographic variables, scholastic variables, sport factors, and substance abuse data (smoking habits, drugs consumption and alcohol consumption using the AUDIT questionnaire). Descriptive statistics, frequencies, analyses of the differences and correlational analyses were performed.ResultsOur results found that greater than one-third of the boys and one-fourth of the girls were daily smokers, and almost half of the boys and one-fifth of the girls practiced harmful drinking; other drugs (i.e. heroin, cocaine, amphetamines, etc.) were rarely consumed. Boys dominated in sport factors, whereas girls were more successful in scholastic achievement. Approximately 23% of the boys and 6% of the girls reported that they practiced harmful drinking and smoked simultaneously. Educational failure, which was defined as having one or more negative grades at the end of the last two school years, was identified in 20% of the boys and 9% of the girls. In both genders, substance abuse was negatively correlated with educational achievement, and half of those students who failed educationally reported daily smoking. Among the girls who experienced education failure, 33% were smokers, and 22% practiced harmful drinking. Sport factors were weakly correlated with substance abuse in boys; thus, we could not support the hypothesis that sports are a protective factor against substance abuse among male adolescents. In girls, participation in team sports was related with a higher incidence of smoking, but there was no evidence of sport factors having an influence on the consumption of alcohol.ConclusionIn this study, the incidence of smoking and the consumption of alcohol were alarmingly high. These findings demonstrate the need for intervention programs to address these issues. These problems are particularly important, considering that substance abuse has a negative impact on educational achievement among boys and girls, and sport factors have not been found to be protective factors against substance abuse.

Substance use and misuse among professional ballet dancers.

This study investigated substance use and misuse among 16 female and 9 male Croatian ballet professionals in 2008 using an original questionnaire. We analyzed social, personal, activity- and training-related, and educational factors, and criteria such as: binge alcohol drinking, cigarette smoking, appetite suppressant consumption, analgesic use, and actual and potential “doping” habits. Frequency tables and rank-order correlation were calculated. More than one third of the male dancers reported binge drinking, while 20% of the females smoked more than a box of cigarettes per day. Almost 25% of these dancers will use “doping” if it will ensure successful ballet performance, regardless of negative health consequences. In males, the risk of potential “doping” behavior increased with age. In females, education level was negatively related to cigarette smoking, but positively correlated to potential “doping” habits and behavior. In both genders, religiousness was the factor negatively related to the following: (1) potential “doping” behavior and (2) belief that “doping” exists in professional ballet. Results suggest that there is evident need for more specific medical and/or psychological services in professional ballet. The studys limitations are noted.

Can We Consider Religiousness as a Protective Factor Against Doping Behavior in Sport

Religiousness is rarely studied in relation to doping behaviors in sport. In this study, we sampled 27 weightlifting/powerlifting athletes from Bosnia and Herzegovina. Using the originally developed questionnaire and by means of Spearman’s correlation, we interpreted data and discussed relationships between (a) social, religious, sport, and educational factors, and (b) substance use criteria, including cigarettes, alcohol, analgesics, nutritional supplementation, and doping behaviors. In conclusion, we found (1) that religiousness can be considered as a potential protective factor against doping, but also (2) that religious subjects tend to deny and underestimate the doping behaviors in their sport. Both of these findings should be extensively studied in future investigations.

Substance Use and Misuse Among Slovenian Table Tennis Players

Substance use and misuse (SU&M) is regularly studied in sports, but we have found no such data for table tennis. We have studied SU&M in athletes competing at the Slovenian Nationals 2008–2009 (responding rate was 100%%; 50 males and 29 females; aged 18 years or older). The anonymous questionnaire for studying SU&M and corresponding educational, socio-demographic, and sport factors was used. More than 90%% of all the athletes included in our study do not rely on coaches’ and/or physicians’ opinion regarding nutritional supplements and doping. Chi-square test revealed higher prevalence of binge drinking, cigarette smoking, and potential doping behavior in males. In both genders, with the advancement of the sport status, the probability for potential doping behavior increases. In conclusion, we strongly suggest permanent SU&M educational programs for table tennis athletes as well as for their coaches and physicians.

Religiousness as a Protective Factor for Substance Use in Dance Sport

Although religiousness is found to be a significant protective factor in substance use, there is an evidential lack of studies of such in athletes. The aim of the study was to identify the predictive value of the religiousness and some social, educational, and sport factors on substance use in 43 sport dancers. An originally developed questionnaire for studying substance use and precipitation factors was applied. The Chi-square showed male dancers as more religious than females. Using the Spearman’s correlation, religiousness was found to be a significant protective factor in cigarette smoking, sport nutritional supplementation, and the likelihood of doping. Data were interpreted emphasizing the previous findings from the literature.

Substance use and misuse among 17- to 18-year-old Croatian adolescents: correlation with scholastic variables and sport factors.

Substance use and misuse (SUM) and the relation to physical activity/exercise/athletic participation (sport factors) and scholastic achievement are rarely studied in Croatia. The aim of this study was: (1) to investigate the SUM habits in Croatian adolescents (17–18 years of age, 254 males, and 218 females), and (2) to study potential gender-specific interrelationships between scholastic and sport factors in relation to SUM. The testing was done using an extensive, anonymous, self-administered questionnaire that consisted of scholastic variables, sport factors, and SUM data. Descriptive statistics, counts, and proportions were calculated. Gender differences were established using the Kruskal–Wallis test. Gender-specific correlations within and between studied variables were established using the Spearmans correlation. The incidence of smoking habits and alcohol consumption among Croatian adolescents was alarming, and a serious intervention program should be developed to address this issue. Educational achievement was negatively related to SUM, with no gender-specific relationships. The data indicated some “protective” effects of the sport factors against SUM in boys, but a significant positive correlation between alcohol drinking and sport participation in girls was also noted.

Dietary supplementation and doping-related factors in high-level sailing

BackgroundAlthough dietary supplements (DSs) in sports are considered a natural need resulting from athletes’ increased physical demands, and although they are often consumed by athletes, data on DS usage in Olympic sailing are scarce. The aim of this study was to study the use of and attitudes towards DSs and doping problems in high-level competitive sailing.MethodsThe sample consisted of 44 high-level sailing athletes (5 of whom were female; total mean age 24.13 ± 6.67 years) and 34 coaches (1 of whom was female; total mean age 37.01 ± 11.70). An extensive, self-administered questionnaire of substance use was used, and the subjects were asked about sociodemographic data, sport-related factors, DS-related factors (i.e., usage of and knowledge about DSs, sources of information), and doping-related factors. The Kruskal-Wallis ANOVA was used to determine the differences in group characteristics, and Spearman’s rank order correlation and a logistic regression analysis were used to define the relationships between the studied variables.ResultsDS usage is relatively high. More than 77% of athletes consume DSs, and 38% do so on a regular basis (daily). The athletes place a high degree of trust in their coaches and/or physicians regarding DSs and doping. The most important reason for not consuming DSs is the opinion that DSs are useless and a lack of knowledge about DSs. The likelihood of doping is low, and one-third of the subjects believe that doping occurs in sailing (no significant differences between athletes and coaches). The logistic regression found crew number (i.e., single vs. double crew) to be the single significant predictor of DS usage, with a higher probability of DS consumption among single crews.ConclusionBecause of the high consumption of DSs future investigations should focus on real nutritional needs in sailing sport. Also, since athletes reported that their coaches are the primary source of information about nutrition and DSs, further studies are necessary to determine the knowledge about nutrition, DSs and doping problems among athletes and their support teams (i.e., coaches, physicians, and strength and conditioning specialists).

Religiousness as a Factor of Hesitation Against Doping Behavior in College-Age Athletes

Religiousness is rarely studied as protective factor against substance use and misuse in sport. Further, we have found no investigation where college-age athletes were sampled and studied accordingly. The aim of the present study was to identify gender-specific protective effects of the religiousness (measured by Santa Clara Questionnaire) and other social, educational, and sport variables as a potential factors of hesitation against doping behaviors in sport-science-students from Mostar, Bosnia, and Herzegovina (51 women and 111 men; age range, 18–26). The gender differences for the non-parametric variables were established by Kruskall–Wallis test, while for the parametric variables the t-test for independent samples was used. Multiple regression calculations revealed religiousness as the most significant predictor of the social, health, sport and legal factors of hesitation against doping behaviors in both genders. However, the differential influence of the social, educational, sport and religious factors in relation to negative consequences of the doping behaviors is found for men and women. Such differential influence must be emphasized in tailoring the anti-doping policy and interventions.