Effect of 6-weeks WBVT on the behaviour of the lower limb muscle fibres during vertical jumping

The purpose of the current study was to examine the effect of 6 weeks of whole body vibration training (WBVT) on body composition, muscle activity of the gastrocnemius and vastus lateralis, gastrocnemius muscle architecture (static and dynamic) and ground reaction forces (performance jump) during the take-off phase of a countermovement jump in young healthy adult males. A total of 33 men (23.31 ± 5.62 years) were randomly assigned to a whole body vibration group (experimental group, EG_WBVT: n = 17; 22.11 ± 4.97 years) or a control group (CG: n = 16; 24.5 ± 6.27 years). The total duration of the intervention phase (WBVT) was 6 weeks with a frequency of 3 sessions per week. Statistically significant differences were observed (P ≤ 0.05) between pre- and post-test in the power peak (Δ 1.91 W · kg^?1; P = 0.001), take-off velocity (0.1 cm · s^?1; P = 0.002) and jump height (Δ 0.4 cm; P = 0.002) for EG_WBVT. There were no statistically significant differences in any of the body composition and muscle architecture variables. Moreover, no significant differences were found between EG_WBVT and CG nor changes in muscle activity during take-off phase of the gastrocnemius and vastus lateralis pre- versus post-training. This study suggests that a 6-week WBVT programme with increasing intensity improves jump performance but does not alter muscle activity nor muscle architecture in healthy young men.     

PGDnet: a new problem‐solving virtual learning environment

The purpose of this paper was to provide information about the virtual learning environment known as PGDnet (the Spanish acronym for Plataforma de Gestión Docente or Educational Management Platform in English), which was developed by the innovative education group at the Technical University of Madrid known as “Nuevas metodologías docentes en ingeniería mecánica y fabricación” (New Teaching Methodologies in Mechanical Engineering and Manufacturing). This tool has been created on an ad hoc basis to cover specific teaching requirements for some engineering courses, which would be difficult to implement on general educational platforms such as Moodle or Blackboard. PGDnet was essentially created as an online engineering problem‐solving tool. These exercises are checked and corrected automatically, providing students with their final and partial scores, and with the solutions to these various sections. A stochastic programming model selects different exercises each time that an activity is performed and attaches the tables, graphs, figures and annexes that are needed for their resolution in each case. As is common with these types of tools, PGDnet provides effective management of publication and delivery dates for the proposed work, and contains records and databases, which allow the stored information to be processed. Its main features include ease of use, reliability and great versatility as a specific tool in the area of technical university education.     

Measuring instructional practice in science using classroom artifacts: lessons learned from two validation studies

With growing interest in the role of teachers as the key mediators between educational policies and outcomes, the importance of developing good measures of classroom processes has become increasingly apparent. Yet, collecting reliable and valid information about a construct as complex as instruction poses important conceptual and technical challenges. This article summarizes the results of two studies that investigated the properties of measures of instruction based on a teacher‐generated instrument (the Scoop Notebook) that combines features of portfolios and self‐report. Classroom artifacts and teacher reflections were collected from samples of middle school science classrooms and rated along 10 dimensions of science instruction derived from the National Science Education Standards; ratings based on direct classroom observations were used as comparison. The results suggest that instruments that combine artifacts and self‐reports hold promise for measuring science instruction with reliability similar to, and sizeable correlations with, measures based on classroom observation. We discuss the implications and lessons learned from this work for the conceptualization, design, and use of artifact‐based instruments for measuring instructional practice in different contexts and for different purposes. Artifact‐based instruments may illuminate features of instruction not apparent even through direct classroom observation; moreover, the process of structured collection and reflection on artifacts may have value for professional development. However, their potential value and applicability on a larger scale depends on careful consideration of the match between the instrument and the model of instruction, the intended uses of the measures, and the aspects of classroom practice most amenable to reliable scoring through artifacts. We outline a research agenda for addressing unresolved questions and advancing theoretical and practical knowledge around the measurement of instructional practice. © 2011 Wiley Periodicals, Inc. J Res Sci Teach 49: 38–67, 2012     

Development and validation of Coaches’ Interpersonal Style Questionnaire

Purpose: The objectives were to develop and validate the Coaches’ Interpersonal Style Questionnaire. The Coaches’ Interpersonal Style Questionnaire analyzes the interpersonal style adopted by coaches when implementing their strategy of supporting or thwarting athletes’ basic psychological needs. Method: In Study 1, an exploratory factor analysis was performed with 265 Spanish male athletes, between 11- and 17-years-old, to confirm the internal structure of the questionnaire. Study 2 was conducted with 430 athletes, also between 11- and 17-years-old. Both confirmatory factor analysis and exploratory structural equation modeling were used to test a set of alternative models to find the best measurement model. Results: The hierarchical exploratory structural equation modeling model showed the best fit to the data and acceptable standardized factor loadings. Concurrent validity was revealed through correlational analysis of the basic psychological need satisfaction and frustration. Conclusion: This study provides a multi-dimensional questionnaire to assess coaches’ interpersonal style perceived by athletes.     

Reliability of power and velocity variables collected during the traditional and ballistic bench press exercise

This study aimed to examine the reliability of different power and velocity variables during the Smith machine bench press (BP) and bench press throw (BPT) exercises. Twenty-two healthy men conducted four testing sessions after a preliminary BP one-repetition maximum (1RM) test. In a counterbalanced order, participants performed two sessions of BP in one week and two sessions of BPT in another week. Mean propulsive power, peak power, mean propulsive velocity, and peak velocity at each tenth percentile (20–70% of 1RM) were recorded by a linear transducer. The within-participants coefficient of variation (CV) was higher for the load–power relationship compared to the load–velocity relationship in both the BP (5.3% vs. 4.1%; CV ratio = 1.29) and BPT (4.7% vs. 3.4%; CV ratio = 1.38). Mean propulsive variables showed lower reliability than peak variables in both the BP (5.4% vs. 4.0%, CV ratio = 1.35) and BPT (4.8% vs. 3.3%, CV ratio = 1.45). All variables were deemed reliable, with the peak velocity demonstrating the lowest within-participants CV. Based upon these findings, the peak velocity should be chosen for the accurate assessment of BP and BPT performance.     

Engines at top speed! Using the adventures of a comic book motorsports hero as an approach to understanding recent French history

Jean Graton created a series of comic books called Michel Vaillant, and its motorsports hero bore the same name. Michel Vaillant made his first appearance in 1957 in the weekly Tintin. Young French boys who loved adventure, sports and car racing greeted this publication with great enthusiasm. We studied the first series of Michel Vaillant, composed of 16 comic books produced in the 1960s. We have departed from traditional approaches and have based our method on the analysis of the sources of Graton’s inspiration. We link these sources to the comics’ text bubbles, visual signs and iconic meanings of the drawings. Our analysis of the comics’ iconography based on the establishment of a mass culture dedicated to the automobile brings to light the existence of an urge to go beyond the limits of tradition. Our research highlights that the success of Michel Vaillant is due, in the main, to the series’ detailed knowledge of the automobile sports industry, and to the myths of speed, youth and progress that it promulgates – myths in which its young male readers could see themselves reflected and which would also prepare them for the future.     

The effects of service convenience and perceived quality on perceived value,satisfaction and loyalty in low-cost fitness centers

Due to its importance in fitness centers, a number of authors have explored and analyzed loyalty. However, two characteristics not yet examined are service convenience in fitness center chains and low-cost fitness centers (an emerging business model). In the present study, the authors sought to understand the relationship among perceived quality and service convenience on perceived value, satisfaction, and client loyalty in low-cost fitness centers. Clients (N = 763; 381 women and 382 men) from three low-cost Spanish fitness centers were surveyed, revealing a positive relationship among the variables studied. Findings demonstrate the importance of proper management of non-monetary sacrifices and perceived quality by the managers of these sport organizations, since client loyalty could depend on factors of these emerging sport models.     

Swimming and peak bone mineral density: A systematic review and meta-analysis

This meta-analysis aims to determine the effects of regular swimming on bone mineral density (BMD) in young adults (18–30 years). A systematic search was performed in Pubmed, SPORTDiscus and the Cochrane Library from the earliest possible year to March 2016. Swimmers were compared to non-athletic controls (CG) and to high-impact athletes (HIGH). Effect sizes with the Hedges g in random effects models were developed. Fourteen studies met the inclusion criteria and were included in the meta-analyses. Swimmers presented similar BMD values to CG in whole-body (g = ?0.20; P = 0.251), femoral neck (g = ?0.05; P = 0.818) and lumbar spine (g = 0.18; P = 0.492); and lower BMD in the whole-body (g = ?1.21; P < 0.001), femoral neck (g = ?1.51; P < 0.001) and lumbar spine (g = ?0.84; P = 0.017) than the HIGH. For the whole-body differences, the higher the latitude the smaller the differences between swimmers and HIGH (B = 0.10; P = 0.001). For the femoral neck differences, age also seemed to reduce the differences between groups (B = 0.19; P = 0.020). Young adult swimmers present similar BMD values than CG and lower values than HIGH.     

Effects of resistance training on performance in previously trained endurance runners: A systematic review

The aim of this work was to identify, synthesize and evaluate the results of randomized controlled trials examining the effects of resistance training on performance indicators in previously trained endurance runners. A database search was carried out in PubMed, Science Direct, OvidSPMedLine, Wiley, Web of Science, ProQuest and Google Scholar. In accordance with the PRISMA checklist, 18 published articles dated prior to May 2016 involving 321 endurance runners were reviewed using the PEDro scale. Resistance training led to general improvements in muscular strength, running economy, muscle power factors, and direct performance in distances between 1,500 and 10,000 m. Such improvements were not accompanied by a significant increase in body mass or signs of overtraining. However, improvements did not occur in all cases, suggesting that they might depend on the specific characteristics of the resistance training applied. Although current evidence supports the effectiveness of resistance training to improve performance in already trained endurance runners, the methodological inconsistencies identified suggest that the results should be interpreted with caution. Future studies ought to investigate the benefits of resistance training in endurance runners while considering the existence of possible differentiated effects based on the specific characteristics of the resistance training carried out.