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81.
The aim of this study was to determine whether gait cycle characteristics are associated with running economy in elite Kenyan runners. Fifteen elite Kenyan male runners completed two constant-speed running sets on a treadmill (12 km ·h?1 and 20 km ·h?1). VO2 and respiratory exchange ratio values were measured to calculate steady-state oxygen and energy cost of running. Gait cycle characteristics and ground contact forces were measured at each speed. Oxygen cost of running at different velocities was 192.2 ± 14.7 ml· kg?1· km?1 at 12 km· h?1 and 184.8 ± 9.9 ml· kg?1· km?1 at 20 km· h?1, which corresponded to a caloric cost of running of 0.94 ± 0.07 kcal ·kg?1·km?1 and 0.93 ± 0.07 kcal· kg?1· km?1. We found no significant correlations between oxygen and energy cost of running and biomechanical variables and ground reaction forces at either 12 or 20 km· h?1. However, ground contact times were ~10.0% shorter (very large effect) than in previously published literature in elite runners at similar speeds, alongside an 8.9% lower oxygen cost (very large effect). These results provide evidence to hypothesise that the short ground contact times may contribute to the exceptional running economy of Kenyan runners.  相似文献   
82.
This study aimed to compare the effect of 6 weeks of resistance training or combined resistance training and change of direction exercises on physical performance and motor skills in futsal players. Thirty-four futsal players were divided into full squat group (SG, n = 12), combined full squat and change of direction exercises group (S+CDG, n = 12) and control group (CG, n = 10). The resistance training for SG consisted of full squat with low load (~45–58% 1RM) and low volume (4–6 repetitions), whereas the S+CDG performed the same resistance training program combined with loaded change of direction. Sprint time in 10 and 20 m, change of direction test, countermovement vertical jump (CMJ) height, maximal strength and force–velocity relationship in full squat exercise, kicking speed ball (BSmean) and repeated sprint ability (RSAmean) were selected as testing variables. Both experimental groups showed significant improvements for CMJ, BSmean and all strength parameters. Only SG resulted in significant sprint gains, whereas S+CDG also achieved significant improvements in RSAmean. The CG remained unchanged after training period. No significant differences were found between both experimental groups. These findings suggest that only 12 sessions of either lightweight resistance training alone, lifting the load at maximal intended velocity or combined with change of direction exercises is enough to improve several physical and skills capacities critical to futsal performance in adult players.  相似文献   
83.
The aim of this cross-sectional study was to compare bone mass in young female athletes playing ball games on different types of playing surfaces. About 120 girls, 9–13 years of age (10.6 ± 1.5 years old Tanner I–III) were recruited and divided into prepubertal and pubertal groups. The sample represented 3 groups of athletes: soccer (N = 40), basketball (N = 40), and handball (N = 40); and 6 different playing surfaces (soccer – ground, soccer – artificial turf, basketball – synthetic, basketball – parquet, handball – synthetic, and handball – smooth concrete). Total and regional body composition (bone mass, fat mass, and lean mass) were measured by dual-energy X-ray absorptiometry (DXA). The mechanical properties of the surfaces (force reduction, vertical deformation, and energy return) were measured with the Advanced Artificial Athlete (Triple A) method. The degree of sexual development was determined using Tanner test. The pubertal group showed that soccer players on the ground, basketball players on synthetic, and handball players on smooth concrete had higher values of bone mineral content (BMC) and bone mineral density (BMD) (< 0.05) than the soccer players on the artificial turf, basketball players on parquet, and handball players on synthetic. In conclusion, a hard playing surface, with less vertical deformation and force reduction, and greater energy return, is associated with higher levels of BMD and BMC in growing girls, regardless of the sport they practice.  相似文献   
84.
The purpose of this study was to analyse associations between lean soft tissue (LST), a surrogate of skeletal muscle mass and key fracture-related geometric characteristics of the proximal femur. Moreover, we examined the role that muscle played on the proximal femur geometry in response to physical activity (PA). Participants were 83 young adults. Leg LST (exposure) was assessed by dual energy X-ray absorptiometry (DXA). Proximal femur geometry was derived from a left hip DXA scan. Geometric variables (outcomes) included the femoral neck axis length (FNAL), the femoral neck width (FNW), the neck–shaft angle and FNW|FNAL (an index of robustness). PA was evaluated by accelerometry. Linear regression was used to analyse relationships. Additional exposure variables included body height and mass. In males, leg LST explained 17.4% of variation in FNAL (P < 0.001) and 15% in FNW (P = 0.015). In females, it explained 8.8% of the variance in FNAL (P = 0.020). Associations remained significant in males, but not in females, when vigorous PA was added to the models. These results suggest that public health approaches to promote PA may be particularly important in females since vigorous PA seems to convey advantages in femur geometry and consequently in bone strength.  相似文献   
85.
In this article Abraham Lincoln is considered as an alternative to the usual type of patriot's hero. He reminds us of our great historical failings. He remains a figure of controversy, a national hero in only some corners of society. He is the heroic President who serves as the first compassionate defender of the downtrodden, and he is a hero in those subcultures as well. Lincoln's treatment in the movies is discussed, focusing particularly on the recent movie Lincoln. Lincoln is seen as a match for the usual movie hero. His famous immunity to casual treatment in popular culture is discussed as well.  相似文献   
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Since the time of state socialism, Hungarian sport has been totally financed by the state. Therefore, Hungarian soccer and sponsorship market is a relatively new and unexplored subject of research in the field of sports sponsorship, as most studies so far have focused on the major European soccer leagues. The main objective of this paper, focusing on the Hungarian soccer sponsorship market, was to evaluate the range of soccer sponsorship objectives and the range of evaluation tools that sponsors use to measure the effectiveness of their sponsorships. A combined approach of qualitative and quantitative research methods served as the methodological foundation of this study. In the quantitative phase, representatives of the sponsor companies (n=103) were asked to rate the importance of the sponsorship objectives and the importance of the evaluation techniques used to measure the effectiveness of their sponsorships. The results of this study have implications for the sports sponsorship industry, the Hungarian soccer club sponsors, and the sport properties too. According to the research results, many of the Hungarian sponsor companies have failed to assess the effectiveness of sponsorship in meeting their objectives. The research can be used to bridge the gap between the theory and practice of soccer sponsorship in Hungary.  相似文献   
89.
As part of Ireland's National Digital Strategy, high-speed broadband is being rolled out to all second-level schools to support greater use of information and communication technology (ICT) in education. This programme signals a move from slow and unreliable broadband connections for many schools to a guaranteed high-speed connection with technical support. Theoretically, this should allow for behaviours and pedagogies to adapt, incorporating ICT into education. Research shows that integrating ICT into teaching and learning is a gradual process for most teachers and is influenced by a complex mix of socio-technical factors. Our data set consists of survey data from teachers and principals from a sample of second-level schools. The survey collected factual and attitudinal variables including attitudes towards ICT integration, current availability of infrastructure and barriers to ICT use, before schools received high-speed broadband connectivity. We examine the factors influencing teachers’ attitudes to ICT and their perceived barriers in adopting new technologies in their day-to-day teaching. Analysis of this baseline period is essential in an iterative digital strategy, informing future strategies, targeting policy most effectively and achieving policy objectives. While attitudes towards the potential of high-speed broadband and use of ICT are consistently positive across sub groups of schools and teachers, perceived barriers to ICT usage differ.  相似文献   
90.

A semi-structured interview was used to enquire into the knowledge of models and modelling held by a total sample of 39 Brazilian science teachers working in 'fundamental' (ages 6-14 years) and 'medium' (ages 15-17 years) schools, student teachers, and university teachers. This paper focuses on their perceptions of the role of models in science teaching. The teachers' ideas are organized in three groups: the status and value of models; the influences that inform the translation of these general ideas into classroom practice; and how they respond to the outcomes of students' modelling activities. The teachers interviewed generally showed an awareness of the value of models in the learning of science but not of their value in learning about science. They were also uncertain of the relationship that could exist in the classroom between various types of models. Modelling, as an activity by students, whilst praised in theory, would not seem to be widely practised. Where practised, the outcomes are by no means always treated with that integrity that learning about science would call for.  相似文献   
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