Jump higher,run faster: effects of diversified sport participation on talent identification and selection in youth basketball

ABSTRACT

The aims of this study were to examine the medium-term effects of previous experiences during early stages of sport development on physical capacities of under-13 (U-13) talented basketball players and, to identify variables that discriminated under-14 (U-14) national team training camp selection. Anthropometrical and physical measurements were collected during a basketball training camp. Previous sport experiences (6–10 years), maturity offset, power outputs for jumping and sprinting were determined. A cluster analysis was used to allocate the subjects according to their different levels of sport experiences (more specialized vs. less specialized) to allow creating a dummy variable for the subsequent analysis of the physical variables. A stepwise discriminant analysis was computed to identify the construct that best classifies selected and non-selected players for U-14 national team training camp. The less specialized group outscored more specialized in all physical parameters, irrespectively of gender. The Abalakov Jump Peak Power and Predicted Adult Height (PAH) could successfully discriminate selected from non-selected players for U-14 national team training camp in boys and PAHin girls. The diversified and non-specific sport stimulus during early ages seem to be determinant to the acquisition and development of fundamental movement skills of talented basketball players.     

Comparison of different theoretical models estimating peak power output and maximal oxygen uptake in trained and elite triathletes and endurance cyclists in the velodrome

Abstract

The primary objective of this study was to examine the relationship between heart rate intensity and pedometer step counts in adolescents. To determine cardiorespiratory fitness, 106 participants (47 boys, 59 girls, mean age 14.2 years, s = 0.8) completed the Queen's College Step Test and were classified as having low, moderate or high cardiorespiratory fitness. Adolescents also completed a 10-min treadmill trial while wearing a pedometer and heart rate monitor. The participants were instructed to maintain their heart rate between 65 and 75% of their maximum heart rate while running or walking on a treadmill. A heart rate of 65–75% maximum was associated with 146 steps per minute (s = 22) in boys and 137 steps per minute (s = 22) in girls. Results of analysis of variance indicated that there was a main effect for level of fitness (F _2,102 = 9.36, P < 0.001). The correlation between mean steps per minute and estimated maximum oxygen consumption was statistically significant (r = 0.44, P < 0.001). The results from this study suggest that a step rate of 130 steps per minute is equal to 65–75% maximum heart rate in low-fit adolescents and achieving 130 steps per minute could be used as an initial goal to improve fitness.     

Determinants and patterns of physical activity practice among Spanish university students

Abstract

The purpose of the present study was to investigate the socio-demographic and lifestyle determinants of physical activity practice, as well as the motivations for being or not being physically active in Spanish university students. A representative sample of students from a Spanish university (n = 2,051; 42.1% males; mean age 21.9, s = 4.8 years) participated in the present cross-sectional study. A questionnaire including questions regarding lifestyle, dietary habits, parents' characteristics, and physical activity habits was administered to the students. The socio-demographic and lifestyle determinants of physical activity practice were assessed using multivariable logistic regression. 68.4% of men and 48.4% of women reported to practise physical activity in the present sample. Those who practised physical activity consumed more fruits and were less likely to be smokers compared to non-physically active students. Also, physically inactive men spent more time in front of the computer and physically inactive women spent more time in front of the TV and were more likely to be frequent alcohol consumers. Maternal educational level and maternal physical activity habits were also important determinants of physical activity practice among men and women respectively. In conclusion, physically active students tended to engage in other healthy habits in the present population, suggesting the clustering of healthy or unhealthy lifestyle factors among specific subgroups.     

The Mutual Shaping of Technology and Society in Videotex Newspapers: Beyond the Diffusion and Social Shaping Perspectives

This article argues that a mutual shaping lens enables a more encompassing account of the joint processes of technological and social change in new media than the diffusion of innovations and social shaping of technology perspectives. Drawing from recent work in sociology and history of technology, organization studies, social informatics, and computer-supported cooperative work, this article suggests that the shaping and diffusion of media artifacts are so intimately tied that they should be seen as the two sides of the same innovation coin. Using examples from the history of videotex newspapers in the United States, the analysis shows that actors simultaneously pursued interdependent technological and social transformations, that this was an ongoing process in which partial outcomes in the technological domain influenced social events at a later phase—and vice versa—and that such process was influenced by historical developments.     

Technical Reliability Assessment of the Actigraph GT1M Accelerometer

The purpose of this study was to determine the reliability of the Actigraph GT1M (Pensacola, FL, USA) accelerometer activity count and step functions. Fifty GT1M accelerometers were initialized to collect simultaneous acceleration counts and steps data using 15-sec epochs. All reliability testing was completed using a mechanical shaker plate to perform six different test conditions in Experiment 1 and 18 test conditions in Experiment 2. The overall intra- and inter-instrument reliability of the GT1M was CV_intra = 2.9% and CV_inter = 3.5% for counts and CV_intra = 1.1% and CV_inter = 1.2% for steps. No batch effects were evident in the 50 GT1Ms. The Actigraph GT1M accelerometer demonstrated good reliability for measuring both counts and steps. However, the ability of the GT1M to consistently detect acceleration at a given acceleration and frequency condition varied widely. Future studies clarifying the filtering limitations and the threshold necessary to detect the occurrence of movement are warranted.     

Effects of mat characteristics on plantar pressure patterns and perceived mat properties during landing in gymnastics

Shock absorption and stability during landings is provided by both, gymnast ability and mat properties. The aims of this study were to determine the influence of different mat constructions on their energy absorption and stability capabilities, and to analyse how these properties affect gymnast's plantar pressures as well as subjective mat perception during landing. Six mats were tested using a standard mechanical drop test. In addition, plantar pressures and subjective perception during landing were obtained from 15 expert gymnasts. The different mats influenced plantar pressures and gymnasts' subjective perception during landing of gymnasts. Significant correlations between plantar pressures at the medial metatarsal and lateral metatarsal zones of the gymnasts' feet with the different shock absorption characteristics of the mats were found. However, subjective perception tests were not able to discriminate mat functionality between the six mats as no significant correlations between the mechanical mat properties with the subjective perception of these properties were found. This study demonstrated that plantar pressures are a useful tool for discriminating different landing mats. Using similar approaches, ideally including kinematics as well, could help us in our understanding about the influences of different mats upon gymnast-mat interaction.     

Self-esteem and Academic Achievement Among Adolescents

The main purpose of this research is to analyse what strategies are pursued in order to protect self-esteem when it is threatened by a negative self-evaluation of school competence. Participants were 838 secondary-school students from the seventh to the ninth grades. Data were collected using Harter's Self-Perception Profile for Adolescents, together with a Scale of Attitudes towards School. Our results show that there are significant differences between the self-esteem enjoyed by successful and unsuccessful students in the seventh grade; such differences disappear in the eighth and ninth grades. They also reveal success-related differences in domain-specific self-evaluation. We also found that students with low levels of academic achievement attribute less importance to school-related areas and reveal less favourable attitudes towards school. We discuss these results in terms of Harter's self-esteem model and Robinson and Tayler's self-esteem protection model.     

Comparative analysis of expectancies of efficacy in in-service and prospective teachers

This study examines the beliefs about effective teaching in student teachers and inservice teachers. We constructed a measurement composed of an adaptation in Spanish of the Gibson and Dembo's (1984. Teacher efficacy: A construct validation. Journal of Educational Psychology, 76, 569–582). Teacher Efficacy Scale and of the items included in Emmer and Hickman's (1991. Teacher efficacy in classroom management and discipline. Educational and Psychological Measurement, 51, 755–765) “classroom management/discipline efficacy” dimension. A total of 339 participants took part in the study. The factor analysis carried out of the results obtained showed three principal factors: classroom management/discipline efficacy, personal teaching efficacy and general teaching efficacy. Analyses which compared efficacy expectancies showed significant differences in the management and discipline dimension in favour of the group of working teachers, whereas an opposite pattern emerged in the general teaching dimension. In addition, there were differences in the management/discipline dimension in terms of the number of years’ experience in the group of inservice teachers. The interpretation of the results is expressed in terms of the Bandura's perceived self-efficacy theory. We also indicate some implications that the analysis of these expectancies may have for the training and professional development of teachers, and we suggest lines for future research.     

Pre-service Teachers’ False Beliefs in Superstitions and Pseudosciences in Relation to Science and Technology

Science & Education - In order to increase scientific competence within the general population, it is important that teachers and educators have a realistic image of science and scientists,...