194 research outputs found
The Association between Relative Age Effect, Goals Scored, Shooting Effectiveness and the Playerâs Position, and her Teamâs Final Classification in International Level Womenâs Youth Handball
Publlisher's version (Ăștgefin grein)The objectives of this study were (i) to determine whether there is a relationship between the relative age effect (RAE) and the final classification of the teams, player's positions, number of goals scored, and shooting effectiveness, and (ii) to determine whether there are differences in the number of goals scored and shooting effectiveness depending on the final classification and player's positions. The study subjects were 380 players who took part in the 2018 Women's Youth World Handball Championship. The independent variables were the relative age effect and the number of goals and shooting effectiveness of each type of shot. The dependent variables were the player's position and the team's final classification. To investigate the relationship between the RAE and the team's final classification, player's position, goals scored, and shooting effectiveness, contingency tables were drawn up and subjected to a chi-squared test. The dependence of the differences in goals and shooting effectiveness on the team's final classification and the player's position was studied by means of an ANOVA with a Tukey post hoc test. For the sample overall, there was no RAE, only an association between the classification and the year of birth, with more players born in the senior year in the teams ranked from 1st to 8th place than in those classified from 9th to 24th place. The teams classified from 1st to 4th had more significant numbers of several variables. There were differences in goals and shooting effectiveness, depending on the player's position."Peer Reviewed
Comparison of Training Volumes in Different Elite Sportspersons According to Sex, Age, and Sport Practised
Training is a complex process that depends, among other factors, on the intensity and volume of training. The objective of this study was to analyse the volume of training in several sports as a function of sex and age. The study sample consisted of 302 sportspersons (men, n=132; women, n=170) who participated in the 16th Games of the Small States of Europe (1st to 6th June 2015) in representing nine countries. The subjects practised the following sports: artistic gymnastics, athletics, basketball, beach volleyball, golf, judo, shooting, swimming, table tennis, tennis, and volleyball, and were classified by sex, sport, and age (younger: = 31 years). They responded to five questions about their training volume and the annual number of competitions in which they participated. A one-way ANOVA with a Bonferroni post hoc test was used to establish differences by sex, sport, and age group. Three-way ANOVAs (sex [men, women] x age [3 levels: younger, intermediate, older] x sport [11 sports]) were performed to determine any relationships between the variables. Neither interactions between the groups nor differences depending on sex were found in the training volumes, but the older the sportsperson, the lower the training volume (days per week, and total time per week). The sports with the greatest training volumes were artistic gymnastics and swimming, while those with the most competitions per year were basketball and volleyball.Peer Reviewe
Design of a Digital-Based, Multicomponent Nutrition Guidance System for Prevention of Early Childhood Obesity
Interventions targeting parenting focused modifiable factors to prevent obesity and promote healthy growth in the first 1000 days of life are needed. Scale-up of interventions to global populations is necessary to reverse trends in weight status among infants and toddlers, and large scale dissemination will require understanding of effective strategies. Utilizing nutrition education theories, this paper describes the design of a digital-based nutrition guidance system targeted to first-time mothers to prevent obesity during the first two years. The multicomponent system consists of scientifically substantiated content, tools, and telephone-based professional support delivered in an anticipatory and sequential manner via the internet, email, and text messages, focusing on educational modules addressing the modifiable factors associated with childhood obesity. Digital delivery formats leverage consumer media trends and provide the opportunity for scale-up, unavailable to previous interventions reliant on resource heavy clinic and home-based counseling. Designed initially for use in the United States, this systemâs core features are applicable to all contexts and constitute an approach fostering healthy growth, not just obesity prevention. The multicomponent features, combined with a global concern for optimal growth and positive trends in mobile internet use, represent this systemâs future potential to affect change in nutrition practice in developing countries
Associations between the duration of active commuting to school and academic achievement in rural Chilean adolescents
Background: Habitual active commuting to school may be positively associated with academic achievement. The aim of this study was to examine the relationship between duration of walking or otherwise actively commuting to school and academic achievement. Methods: This cross-sectional study included 389 adolescents from seven rural schools (12-13 years). Mode and duration of active commuting to school (use of active means such as walking or biking to and from school) and screen time were self-reported. Academic achievement was determined by the outcome in basic grades (language and mathematics). Results: Active commuting to school was not associated with higher scores in any grades after adjustment for potential confounders. No evidence was found of interactions between gender and academic achievement, but there was interaction with duration of walking (<30 min, 30-60 min, and >60 min). Adjusted binary logistic regression analysis suggested that adolescents who spent between 30 and 60 min actively commuting were more likely to obtain high academic achievement (language and mathematics). Conclusions: Thirty to 60 min of ACS may have a positive influence on academic achievement in adolescents, so, it is necessary to make recommendations for the children to walk from and/or to school. This could help society to recognize the relevance of physical activity to health as well as to academic performance. © The Author(s). 2017
Anthropometric charachteristics, physical fitness and the prediction of throwing velocity in handball men young players
The objectives of this study were: (i) to analyse anthropometric parameters, physical fitness, and throwing velocity of handball male elite youth players of different ages; and (ii) to develop a multivariate model that explains throwing velocity. Fifty-three handball men players (17.99±1.68 years old), members of the Icelandic National Teams, participated in the study. The participants were classified into the U21 National Team (n=12), U19 National Team (n=17), and U17 National Team (n=24). All were evaluated by basic anthropometry (body height, body mass, body mass index), physical fitness tests (counter movement jump, medicine ball throw, hand dynamometry, 10 m and 30 m sprint, yo-yo IR2 test) and ball speed after various handball throws at goal (a 7-m throw, a 9-m ground shot after a three-step run-up, and a 9-m jump shot after a three-step approach). A one-way analysis of variance with a Bonferroni post-hoc test was used to establish the differences between the teams. Multiple linear regression was used to predict the speed of the ball from each of the three shots taken for each team. There were no differences between the U21 and U19 teams except for the medicine ball throw, but the U19 team scored better than the U17 team in almost all variables. Ball speed after a handball shot was predicted (between 22% and 70% of accuracy) with only one or two physical fitness variables in each model â medicine ball throw (in four models), counter movement jump (in two models), and 10 m sprint (in two models), being the variables that were most selective
Tracking young talented swimmers: follow-up of performance and its biomechanical determinant factors
The aims of study were to follow-up and analyze the stability of young talent swimmersâ performance and its determinant determinantsfactors (i.e. anthropometrics, kinematics, hydrodynamics and efficiency) during a competitive season. The aim of this study was to assess the anthropometric, kinematic, hydrodynamic and efficiency stability of young swimmersâ performance during a competitive season. Thirty three (15 boys and 18 girls) young swimmers (overall: 11.81 ± 0.75 years old and Tanner stages 1-2 by self-evaluation) were evaluated. Performance, anthropometrics, kinematics, hydrodynamics and efficiency variables were assessed in three time points during a competitive season. Performance had a significant improvement during the season (moderate-high stability). In the anthropometrics domain all variables increased with significant differences between time points (high-very high stability). In the kinematics domain, stroke length and swimming velocity showed significant differences, although stroke frequency and speed fluctuation did not (low-moderate stability). Hydrodynamics did not present significant differences along the season (low-moderate stability). Efficiency variables did present significant variations (but with low stability). Young swimmersâ performance improved during the competitive season, and it seems that anthropometrical variables were the most determinant to this enhancement
Need for Early Interventions in the Prevention of Pediatric Overweight: A Review and Upcoming Directions
Childhood obesity is currently one of the most prevailing and challenging public health issues among industrialized countries and of international priority. The global prevalence of obesity poses such a serious concern that the World Health Organization (WHO) has described it as a âglobal epidemic.â Recent literature suggests that the genesis of the problem occurs in the first years of life as feeding patterns, dietary habits, and parental feeding practices are established. Obesity prevention evidence points to specific dietary factors, such as the promotion of breastfeeding and appropriate introduction of nutritious complementary foods, but also calls for attention to parental feeding practices, awareness of appropriate responses to infant hunger and satiety cues, physical activity/inactivity behaviors, infant sleep duration, and family meals. Interventions that begin at birth, targeting multiple factors related to healthy growth, have not been adequately studied. Due to the overwhelming importance and global significance of excess weight within pediatric populations, this narrative review was undertaken to summarize factors associated with overweight and obesity among infants and toddlers, with focus on potentially modifiable risk factors beginning at birth, and to address the need for early intervention prevention
Tracking young talented swimmers: follow-up of performance and its biomechanical determinant factors
The aim of the study was to follow-up the stability of young talented swimmers' performance and its biomechanical determinant factors (i.e., anthropometrics, kinematics, hydrodynamics and efficiency) during a competitive season. Thirty three (15 boys and 18 girls) young swimmers (overall: 11.81 ± 0.75 years old and Tanner stages 1-2 by self-evaluation) were evaluated. Performance, anthropometrics, hydrodynamics, kinematics and efficiency variables were assessed at three moments during a competitive season. Performance had a significant improvement (with minimum effect size) and a moderate-very high stability throughout the season. In the anthropometrics domain all variables increased significantly (ranging from without to minimum effect size) between moments and had a moderate-very high stability. Hydrodynamics presented no variations between all moments and had a low-very high stability throughout the season. In the kinematics domain, there were no variations between moment one and three, except for an increase in stroke frequency (without size effect). Speed fluctuation remained constant, with no significant variations. All kinematic variables had a low-very high stability. Efficiency variables did not present variations between moment one and three and had a low-moderate stability. Overall, young swimmers showed a minimum improvement in performance and in anthropometric factors; and a moderate stability of performance and its determinant factors (i.e., anthropometrics, hydrodynamics, kinematics and efficiency) during the competitive season.info:eu-repo/semantics/publishedVersio
Women\u27s beach handball game statistics: Differences and predictive power for winning and losing teams
The objectives of the present study were: (i) to compare beach handball game-related statistics by match outcome (winning and losing teams), and (ii) to identify characteristics that discriminate performances in the match. The game-related statistics of the 72 womenâs matches played in the VIII Womenâs Beach Handball World Championship (2018) were analysed. The game-related statistics were taken from the official Web page. A validation of the data showed their reliability to be very good (the inter-observer mean reliability was α=0.82 and the intra-observer mean was α=0.86). For the differences between winning/losing teams a parametric (unpaired t-test) or non-parametric (Mann-Whitney U test) test was applied depending on whether the variable met or did not meet normality, respectively. A stepwise discriminant analysis was then performed to determine the variables that predicted performance (victory or defeat). Five variables showed differences between the winning and losing teams: total points (p<.001; ES=1.09), technical faults (p<.001; ES=â0.96), the number of players with either negative (p<.001; ES=â0.86) or positive (p<.001; ES=1.05) valuations and overall valuation (p<.001; ES=1.29). The predictive model correctly classified 80.6% of the matches using two variables (Wilksâs λ=0.618; canonical correlation index=0.618): overall valuation and GK shots
A model for the electromagnetic spectrum of the inner jets of Cen A
Centaurus A, the closest active galaxy, has been detected from radio to
high-energy gamma-rays. The synchrotron radiation by extremely high energy
protons may be a suitable mechanism to explain the MeV to GeV emission detected
by the instruments of the Compton Gamma-Ray Observatory, as coming from the
inner jets. This scenario requires a relatively large magnetic field of about
10^4 G that could be present only close to the central black hole. We
investigate the spectral energy distribution (SED) resulting from a one-zone
compact acceleration region, where both leptonic and hadronic relativistic
populations arise.
We present here results of such a model, where we have considered synchrotron
radiation by primary electrons and protons, inverse Compton interactions, and
gamma-ray emission originated by the inelastic hadronic interactions between
relativistic protons and cold nuclei within the jets themselves. Photo-meson
production by relativistic hadrons were also taken into account, as well as the
effects of secondary particles injected by all interactions. The internal and
external absorption of gamma rays is shown to be of great relevance to shape
the observable SED, which was also recently constrained by the results of HESS.Comment: 13 pages (ref. style), submitted to MNRAS on December 04, 2008.
Waiting for revie
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