How University Students Assess Their Water Skills.

The aim of this study was to determine the gender differences between students' actual and perceived water abilities, how respondents assess risk in the described situations, and whether there are gender differences for those situations. The cross-sectional study was conducted on 150 students aged 19-20 years (males, n = 88; females, n = 62) from the faculty of sport and physical education, University of Novi Sad. Using calculated frequencies and estimates, students' self-assessment and actual measures of their swimming and survival skills and their perceived risk of drowning are described. Based on the results, Mann-Whitney U tests were applied. The differences between independent variables (gender) were analyzed according to dependent measures (water competency). To determine the significance of the relationship between actual and perceived skills, Spearman-rank correlation coefficients were calculated. The results of this study confirmed gender differences between students' actual and perceived water abilities, and that the male and female students had inaccurate perceptions of their own perceived and real water abilities. Both male and female students, with high precision, assessed their ability to swim long distances (rs = 0.601; rs = 0.694) just as female students assessed their ability to float (rs = 0.698). Male students greatly overestimated their backstroke swimming, while female students underestimated their ability to dive into the water. Both groups overestimated underwater swimming and underestimated their surface dive skill. Also, there was gender differences between students in assessing the risk for described situations.

Validity of the Swimming Capacities and Anthropometric Indices in Predicting the Long-Term Success of Male Water Polo Players: A Position-Specific Prospective Analysis over a Ten-Year Period.

Long-term predictors of success in water polo are rarely reported. This study aimed to evaluate the position-specific validity of the swimming and anthropometric/body build tests on the prediction of the long-term success of male water polo players. The participants were 85 top-level players observed at baseline (junior level, when they were 17-18 years of age; 35 centers and 50 perimeter players) in tests of swimming capacities (15 m water polo sprint, 25 m sprint, and 100 and 400 m freestyle swimming) and anthropometric/body build indices (body mass, body height, arm span, body mass index, and body fat percentage). Over a period of 10 years, participants' senior-level success was prospectively observed. Multinomial logistic regression with three levels of criteria (high achievement, medium achievement, and low achievement at the senior level) was applied to identify the predictive validity of the swimming and anthropometric/body build indices. For the total sample (not dividing perimeter from center players), all observed swimming capacities, body height, and arm span were significantly associated with success, with more successful players being taller, with a longer arm span, and superior swimming capacities. Body height and 100 m freestyle swimming were significant predictors of success among centers. Achievement in 100 and 400 m freestyle swimming, body height, and a lower percentage of body fat were correlated with higher senior-level performance in perimeter players. The results showed better validity of the anaerobic-lactate and aerobic swimming tests than sprint swimming in predicting the long-term achievement of male water polo players. Differences in the influence of swimming capacities and body-build indices on senior-level success between observed playing positions are related to differences in game duties, playing time, and consequent metabolic demands.

Change of Direction Speed and Reactive Agility in Prediction of Injury in Football; Prospective Analysis over One Half-Season.

Agility is an important factor in football (soccer), but studies have rarely examined the influences of different agility components on the likelihood of being injured in football. This study aimed to prospectively evaluate the possible influences of sporting factors, i.e., flexibility, reactive agility (RAG), and change of direction speed (CODS), on injury occurrence over one competitive half-season, in professional football players. Participants were 129 football professional players (all males, 24.4 ± 4.7 years), who underwent anthropometrics, flexibility, and RAG and CODS (both evaluated on non-dominant and dominant side) at the beginning of second half-season 2019/20 (predictors). Over the following half-season, occurrence of injury was registered (outcome). To identify the differences between groups based on injury occurrence, t-test was used. Univariate and multivariate logistic regressions were calculated to identify the associations between predictors and outcome. Results showed incidence of 1.3 injuries per 1000 h of training/game per player, with higher likelihood for injury occurrence during game than during training (Odds Ratio (OR) = 3.1, 95%CI: 1.63-5.88) Univariate logistic regression showed significant associations between players' age (OR = 1.65, 95%CI: 1.25-2.22), playing time (OR = 2.01, 95%CI: 1.560-2.58), and RAG (OR = 1.21, 95%CI: 1.09-1.35, and OR = 1.18, 95%CI: 1.04-1.33 for RAG on dominant- and non-dominant side, respectively), and injury occurrence. The multivariate logistic regression model identified higher risk for injury in those players with longer playing times (OR = 1.81, 95%CI: 1.55-2.11), and poorer results for RAG for the non-dominant side (OR = 1.15, 95%CI: 1.02-1.28). To target those players who are more at risk of injury, special attention should be paid to players who are more involved in games, and those who with poorer RAG. Development of RAG on the non-dominant side should be beneficial for reducing the risk of injury in this sport.

Personality Dimensions of Serbian Lifeguards.

According to the World Health Organization's (WHO) global drowning report (2017), drowning is the third leading cause of unintentional injury death worldwide. Drowning can occur anywhere there is water: oceans, seas, lakes, pools, bathtubs, rivers or water collection on the side of the road, etc. In many countries, there are drowning prevention programs for children and adults. The two most commonly used strategiesagainst drowning are the presence of lifeguards in public places and the use of protected areas that could prevent most of the drownings. The main aim of the present study is to examine the individual differences in a Big Five plus Two (BF+2) personality traits in lifeguards and non-lifeguards (including students). The subsample of lifeguards represented 122 male respondents who were, at the time of the survey, licensed as lifeguards (60.9%) or were in training for lifeguards-candidates (39.1%). The subsample of students represented 138 male respondents who were studying at the University of Novi Sad. The results indicate that lifeguards in comparison to students are more extraverted, open to experience, and conscientious, less neurotic, and aggressive. Both positive and negative valence are higher in student subsample. All of the above traits are desirable traits for people working as lifeguards.

The Effect of the COVID-19 Lockdown on the Position-Specific Match Running Performance of Professional Football Players; Preliminary Observational Study.

The COVID-19 pandemic interrupted professional football in the 2019/2020 season, and football experts anticipate that the consequences of lockdown measures will negatively affect the physical performance of players once competition restarts. This study aimed to evaluate position-specific match running performance (MRP) to determine the effect of COVID-19 lockdowns on the physical performance of professional football players. Players' MRPs (n = 124) were observed in matches before and after the COVID-19 lockdown in the 2019/2020 season of the highest level of national competition in Croatia and were classified according to player position: central defenders (CD; n = 42), fullbacks (FB; n = 20), midfielders (MF; n = 46), and forwards (FW; n = 16). The MRPs were measured using Global Positioning System, and included the total distance covered, low-intensity running (≤14.3 km/h), running (14.4-19.7 km/h), high-intensity running (≥19.8 km/h), total accelerations (>0.5 m/s2), high-intensity accelerations (>3 m/s2), total decelerations (less than -0.5 m/s2), and high-intensity decelerations (less than -3 m/s2). The results indicated that, in matches after the COVID-19 lockdown, (i) CDs and FBs featured lower running and high-intensity running (t-value: from 2.05 to 3.51; all p < 0.05; moderate to large effect sizes), (ii) MFs covered a greater distance in low-intensity running and achieved a lower number of total accelerations, and total and high-intensity decelerations (t-value: from -3.54 to 2.46; all p < 0.05, moderate to large effect sizes), and (iii) FWs featured lower high-intensity running (t-value = 2.66, p = 0.02, large effect size). These findings demonstrate that the physical performances of football players from the Croatian first division significantly decreased in matches after the COVID-19 lockdown. A combination of inadequate adaptation to football-specific match demands and a crowded schedule after the competition was restarted most likely resulted in such an effect.

Explosive muscle power assessment in elite athletes using wingate anaerobic test / Avaliação da força muscular explosiva em atletas de elite usando o teste anaeróbico de wingate / Evaluación de la fuerza muscular explosiva en atletas de élite usando la prueba anaeróbica de wingate

ABSTRACT Introduction: Maximal effort physiological tests provide information about the current functional capacity of athletes. Objective: The aim of this study was to evaluate anaerobic performance parameters in elite athletes and to compare them in terms of the specific demands of each sport. We also created and applied the new software which enables us to quantify a new parameter -explosive muscle power (EP), a major component in sports requiring explosive bursts of movement lasting from a few seconds to 1 or 2 minutes. This new parameter reflects the velocity of energy transformation from intramuscular ATP and high-energy phosphates into mechanical power. Methods: All Wingate test parameters (standard parameters) - anaerobic power (AP), anaerobic capacity (AC), and explosive power (EP) as the new parameter were recorded in 104 subjects: 30 non-athletes and 74 athletes divided into different groups depending on their sport specialty (20 rowers, 28 wrestlers and 26 soccer players). Results: Anaerobic power (AP), anaerobic capacity (AC) and explosive power (EP) were significantly higher in the group of athletes compared to non-athletes. Among athletes, significant differences were observed in some parameters according to the type of activities they are involved in. The highest values were recorded in the group of wrestlers (AP=836W; AC=16.6kJ; EP=139W/s). The values of AP (absolute values) and EP (absolute and relative values) were significantly higher in wrestlers than in soccer players and rowers, but there was no significant difference in AC among these groups. The EP variable had a distribution similar to AP. Conclusions: Alongside anaerobic power and anaerobic capacity, the assessment of explosive power may complement the anaerobic profile of athletes. Experts in the field of sports medicine and exercise physiology could find these results useful in improving test variables, which are more important for specific sports, and for evaluating and monitoring training progress. Level of Evidence I; Diagnostic studies - Investigating a diagnostic test.

RESUMO Introdução: Os testes fisiológicos de esforço máximo fornecem informações sobre a capacidade funcional atual dos atletas. Objetivo: O objetivo deste estudo foi avaliar os parâmetros de desempenho anaeróbico em atletas de elite e compará-los em relação às demandas específicas de cada esporte. Além disso, criamos e aplicamos o novo software que possibilita a quantificação de um novo parâmetro - força muscular explosiva (FE), um componente importante em esportes que requerem explosões de movimento que duram de alguns segundos a 1 ou 2 minutos. Este novo parâmetro reflete a velocidade de transformação de energia a partir de ATP e fosfatos de alta energia intramusculares em potência mecânica. Métodos: Todos os parâmetros de teste de Wingate (parâmetros padrão) - potência anaeróbica (PA), capacidade anaeróbica (CA) e força explosiva (FE) como um novo parâmetro foram registrados em 104 indivíduos: 30 não atletas e 74 atletas divididos em diferentes grupos, dependendo da sua especialidade esportiva (20 remadores, 28 lutadores e 26 jogadores de futebol). Resultados: A potência anaeróbica (PA), a capacidade anaeróbica (CA) e a força explosiva (FE) foram significativamente maiores no grupo de atletas em comparação com não atletas. Entre os atletas, diferenças significativas foram observadas em alguns parâmetros, de acordo com o tipo de atividades nas quais eles estão envolvidos. Os valores mais altos foram registrados no grupo de lutadores (PA = 836 W, CA = 16,6 kJ, FE = 139 W/s). Os valores de PA (valores absolutos) e FE (valores absolutos e relativos) foram significativamente maiores em lutadores do que em jogadores de futebol e remadores, mas não houve diferenças significativas na CA entre esses grupos. A variável FE mostrou uma distribuição similar à da PA. Conclusões: Juntamente com o poder anaeróbico e a capacidade anaeróbica, a avaliação da força explosiva pode complementar o perfil anaeróbico dos atletas. Especialistas no campo da medicina esportiva e da fisiologia do exercício poderiam achar esses resultados úteis para melhorar as variáveis de teste que são mais importantes para esportes específicos e para avaliar e monitorar o progresso do treinamento. Nível de Evidência I; Estudo diagnóstico - Investigação de um exame para diagnóstico.

RESUMEN Introducción: Las pruebas fisiológicas de esfuerzo máximo proporcionan información sobre la capacidad funcional actual de los atletas. Objetivo: El objetivo de este estudio fue evaluar los parámetros de rendimiento anaeróbico en atletas de élite y compararlos en relación con las demandas específicas de cada deporte. Además, creamos y aplicamos el nuevo software que permite la cuantificación de un nuevo parámetro - fuerza muscular explosiva (FE), un componente grande en deportes que requieren explosiones de movimiento que duran de unos segundos a 1 o 2 minutos. Este nuevo parámetro refleja la velocidad de transformación de energía a partir de ATP y fosfatos de alta energía intramusculares en potencia mecánica. Métodos: Todos los parámetros de prueba de Wingate (parámetros estándar) - potencia anaeróbica (PA), capacidad anaeróbica (CA) y fuerza explosiva (FE) como un nuevo parámetro fueron registrados en 104 sujetos: 30 no atletas y 74 atletas divididos en diferentes grupos dependiendo de su especialidad deportiva (20 remeros, 28 luchadores y 26 jugadores de fútbol). Resultados: La potencia anaeróbica (PA), la capacidad anaeróbica (CA) y la fuerza explosiva (FE) fueron significativamente mayores en el grupo de atletas en comparación con los no atletas. Entre los atletas, se observaron diferencias significativas en algunos parámetros según el tipo de actividades en las que están involucrados. Los valores más altos fueron registrados en el grupo de luchadores (PA =836 W; CA = 16,6 kJ; FE=139 W/s). Los valores de PA (valores absolutos) y FE (valores absolutos y relativos) fueron significativamente mayores en luchadores que en jugadores de fútbol y remeros, pero no hubo diferencias significativas en CA entre estos grupos. La variable FE mostró una distribución similar a la de la PA. Conclusiones: Junto con la potencia anaeróbica y la capacidad anaeróbica, la evaluación de la fuerza explosiva puede complementar el perfil anaeróbico de los atletas. Los expertos en el campo de la medicina deportiva y la fisiología del ejercicio podrían encontrar estos resultados útiles para mejorar las variables de prueba que son más importantes para deportes específicos y para evaluar y monitorear el progreso del entrenamiento. Nivel de Evidencia I; Estudio diagnóstico - Investigación de un examen para diagnóstico.

Relationship between body mass index and body fat in children-Age and gender differences.

SUMMARY: When defining obesity body mass index (BMI) has been used as the main criterion. However it indicates only the nutritional status, whereas body fat demonstrates the real body composition picture. This study aimed at analyzing the relationship between nutritional status and adiposity in the population of 2284 Serbian children (1217 boys and 1067 girls). According to BMI subjects were divided into underweight, normal-weight, overweight and obese, and %BF values (based on skinfold thickness measurements) were analyzed with regard to BMI-category, age and gender. Girls showed stronger correlation between BMI and %BF comparing to boys (r = 0.834 vs. 0.577). Differences in %BF between underweight, normal weight and overweight children from different age groups were more obvious in girls, whereas in boys younger than 8 years overlapping in %BF values between different BMI-categories was registered. In normal weight children we found age-related oscillations in %BF values: 8- and 9-year-old boys had lower %BF comparing to 7-year-old boys, which was followed by %BF increasement in 10- and 11-year-old ones; in girls %BF values gradually increased with aging, with significant jumps in 9-, 10- and 11-year-old ones. Thus, adiposity rebound may appear somehow later in boys. In overweight and obese children of both genders %BF continually increased with aging, whereas in underweight children %BF values remained unchanged. Our results pointed to age- and gender-dependent variations of %BF in normal weight and overweight children. We also indicated inconsistency between %BF and BMI especially in boys, and the need for definition of references for %BF.: