Robert J. Ritson, Richard J. Smith and Hughie I. Twa
Pedro Figueiredo, Ana Silva, António Sampaio, João Paulo Vilas-Boas and Ricardo J. Fernandes
The aim of this study was to evaluate the determinants of front crawl sprint performance of young swimmers using a cluster analysis. 103 swimmers, aged 11- to 13-years old, performed 25-m front crawl swimming at 50-m pace, recorded by two underwater cameras. Swimmers analysis included biomechanics, energetics, coordinative, and anthropometric characteristics. The organization of subjects in meaningful clusters, originated three groups (1.52 ± 0.16, 1.47 ± 0.17 and 1.40 ± 0.15 m/s, for Clusters 1, 2 and 3, respectively) with differences in velocity between Cluster 1 and 2 compared with Cluster 3 (p = .003). Anthropometric variables were the most determinants for clusters solution. Stroke length and stroke index were also considered relevant. In addition, differences between Cluster 1 and the others were also found for critical velocity, stroke rate and intracycle velocity variation (p < .05). It can be concluded that anthropometrics, technique and energetics (swimming efficiency) are determinant domains to young swimmers sprint performance.
Antonio García de Alcaraz, David Valadés and José M. Palao
To assess the evolution of the volleyball’s game demands throughout players’ development in men’s volleyball.
A total of 150 sets and 6.671 rallies were analyzed. The sample was composed of 30 sets each by under-14, under-16, under-19, national senior, and international senior teams (1.291, 1.318, 1.310, 1.372, and 1.380 rallies for each category, respectively). Sets included in the sample were stratified and then randomly selected. The variables studied included play time, rest time, rallies played, jumps, hits, types of ball contact, types of game interruptions, performance of the game phases, and performance of the actions. Student t and Mann Whitney U tests were used to analyze specific differences between categories.
The results showed significant reductions in the play times of the rally (from 8.91 to 6.79 s) and the set (6 min 23 s to 4 min 30 s), significant increases in the rest times of the rally (19.64 to 26.53 s) and the set (13 min 44 s to 20 min 27 s), and a significant increase in the number of jumps per set (113.5 to 181.3). Significant improvements in the reception performance (1.57 to 2.45 out of 3), attack performance (2.13 to 2.67 out of 4), and side-out-phase success (48.4% to 69.6%) were found. Throughout the players’ development, data show an increase in the speed, intensity, and efficacy of the side-out phase.
The findings provide reference values to guide athletes’ development and to monitor training and matches both physically and technically tactically.
Stein G.P. Menting, Marco J. Konings, Marije T. Elferink-Gemser and Florentina J. Hettinga
participants were categorized in age groups based on the skater’s year of birth and the year in which the analyzed race was performed. Participants younger than 17 years were placed in the group under 17 (U17), participants who were 17 and 18 years old were placed in group under 19 (U19), participants who were
Javier Raya-González, Luis Suárez-Arrones, Archit Navandar, Carlos Balsalobre-Fernández and Eduardo Sáez de Villarreal
number of injuries per 1000 hours of training and overall, and U15 players sustained the highest number of injuries per 1000 hours of matches. On the other hand, another study 12 observed that the greatest time loss per injury was in the U14 to U15 age groups, and the highest rate of severe injuries was
Ken Pitetti, Ruth Ann Miller and E. Michael Loovis
adolescents with developmental disabilities. Data Analysis Data were collected over a 6-year period. Some participants were evaluated 2–6 times as they advanced in age group (Table 3 ). Previous work has established that BOT test scores assessed on a yearly basis are not influenced by a practice effect in
Christina M. Patch, Caterina G. Roman, Terry L. Conway, Ralph B. Taylor, Kavita A. Gavand, Brian E. Saelens, Marc A. Adams, Kelli L. Cain, Jessa K. Engelberg, Lauren Mayes, Scott C. Roesch and James F. Sallis
A common hypothesis is that crime impedes physical activity, but research does not consistently support this assumption. Literature reviews across age groups have revealed inconsistencies in the relationships between crime-related safety and physical activity. 1 – 4 In a review of 41 studies, 22
Yoav Gimmon, Hisham Rashad, Ilan Kurz, Meir Plotnik, Raziel Riemer, Ronen Debi, Amir Shapiro and Itshak Melzer
adults may result from slower walking speeds ( Maki, 1997 ) or possibly from other factors related to aging. In most research studies on the aging populations, subjects are usually grouped into one older group spanning several decades. In this study, we investigate gait within an aging group, as well as
Danielle Nesbitt, Sergio Molina, Ryan Sacko, Leah E. Robinson, Ali Brian and David Stodden
void in understanding not only how movement development occurs, but also in how it relates to health across various ages. Thus, it is logical and necessary to identify developmentally valid and reliable motor competence assessments that can be effectively implemented across various age groups. The
Nicola Brown and Yasmin Bowmer
survey of 1885 women across age groups (teens, 20s, 30s, 40s, 50s, and 60+) revealed that across all ages ‘toned and fit’ was the common motivator ( Gavin, Keough, Abravanel, Mourdrakovski, & Mcbreaty, 2014 ). It is recognized that beginning exercise earlier in life can extend life expectancy and improve