The relationship between evaluative concerns and sport competition state anxiety among youth skiers     

Steven R. Bray  Kathleen A. Martin  W. Neil Widmeyer 《Journal of sports sciences》2013,31(5):353-361

Thirty-four youth competitive skiers (mean age = 13.74 years) completed measures of social evaluative concern and competitive anxiety. Consistent with past research, regression analyses showed that cognitive anxiety was related to performance-specific evaluative concerns. However, contrary to current conceptualizations of sport competition anxiety, somatic anxiety was correlated with concerns about evaluation of other non-performance aspects of ski racing. Competitive skiers were most concerned about parents' and friends' evaluations of their performance, and other competitors' and friends' evaluations of their skiing in general. These findings are discussed in relation to the theory and management of sport competition state anxiety.  相似文献   

The menstrual cycle and its effect on the immune status of female endurance runners     

M. Burrows  S.R. Bird  N. Bishop 《Journal of sports sciences》2013,31(4):339-344

Twenty highly trained, eumenorrhoeic female endurance runners were studied over three consecutive menstrual cycles. Average training distance per week, total years training and mood states were recorded throughout the three cycles. Salivary progesterone and menstrual cycle diaries were recorded over the first two cycles to identify luteal phase onset and the presence of any menstrual irregularities. Saliva samples were collected daily over the third cycle for analysis of immunoglobulin A (IgA) concentration and secretion and saliva flow rate. Twoway analysis of variance (ANOVA) revealed no significant differences in mood states across the phases of the menstrual cycle ( P > 0.05). Training logs indicated that training did not alter throughout the 3 month study. One-way ANOVArevealed no significant differences in IgA concentration ( P = 0.92), secretion rate ( P = 0.84) or saliva flow rate ( P = 0.95) across the phases of the menstrual cycle. Pearson's product-moment correlation revealed no relationship between IgA concentration and progesterone between the phases of the cycle ( r = 0.39). We conclude that, in ovulatory female endurance runners whose physical and emotional stress are stable, IgA concentration is not significantly affected by fluctuations in progesterone during the menstrual cycle.  相似文献   

BASES Position Statement on Guidelines for Resistance Exercise in Young People     

G Stratton  M Jones  KR Fox  K Tolfrey  J Harris  N Maffulli 《Journal of sports sciences》2013,31(4):383-390

Abstract

Despite the performance concerns of dehydration in other sports, there are currently no data on the effects of rapid weight-loss on the physical and cognitive performance of jockeys in a sport-specific context. In a randomised crossover design, eight Great Britain (GB) male licensed jockeys were assessed for chest strength, leg strength, simulated riding performance (assessed by maximum pushing frequency on a mechanical riding simulator during the final two furlongs of a simulated 2 mile race) and simple reaction time after performing 45 min of exercise, during which euhydration was maintained (Control trial) or induced 2% dehydration (Rapid Weight-Loss trial). Reductions in both chest (–13.8 ± 3.03% vs. 0.62 ± 1.04%) and leg strength (–4.8 ± 4.8% vs. –0.56 ± 2.5%) were greater in Rapid Weight-Loss compared with Control (P < 0.01 and P = 0.04, respectively). Similarly, reductions in simulated riding performance were also greater (P = 0.05) in Rapid Weight-Loss (–2.8 ± 4.0%) compared with Control (–0.07 ± 1.5%), whereas there were no significant changes (P = 0.14) in simple reaction time. We conclude that a 2% reduction in body mass, as achieved by 45 min of moderate-intensity exercise undertaken in a sweatsuit (a common method of inducing acute dehydration by jockeys), significantly impairs maximum pushing frequency during a simulated race. In addition, the observed reductions in strength may also increase the occupational hazards associated with race riding.  相似文献   

The home advantage in sport competitions: Courneya and Carron's (1992) conceptual framework a decade later     

Albert V Carron  Todd M Loughhead  Steven R Bray 《Journal of sports sciences》2013,31(4):395-407

This paper had three aims. The first was to review research carried out on the home advantage from 1992 to the present. The second was to examine the extent to which a conceptual framework proposed by Courneya and Carron () was/is viable as a tool to highlight and organize an understanding of the home advantage. The final aim was to provide suggestions for future research.  相似文献   

Batting last as a home advantage factor in men's NCAA tournament baseball     

Steven R Bray  Jeff Obara  Matt Kwan 《Journal of sports sciences》2013,31(7):681-686

In baseball and softball, there is a rule that allows the home team to have the last at-bat and thus the final opportunity to win the game. However, in tournament play, this rule is often set aside and, instead, batting order is decided by other means (e.g. tournament rules, the flip of a coin). The purpose of this study was to examine the impact of the batting last rule on game outcome in NCAA men's regional tournament baseball. It was hypothesized that host (i.e. home) teams would win a greater percentage of the games in which they batted last compared with when they batted first. This hypothesis was not supported. Closer examination of the last inning of play showed home teams were no more likely to have won the game during their last bat than visitors playing other visitors. The results suggest that the batting last rule contributes minimally, if at all, to home advantage in NCAA tournament baseball.  相似文献   

Time–motion analysis of elite field hockey,with special reference to repeated-sprint activity     

Matt Spencer  Steven Lawrence  Claire Rechichi  David Bishop  Brian Dawson  Carmel Goodman 《Journal of sports sciences》2013,31(9):843-850

Limited information exists about the movement patterns of field-hockey players, especially during elite competition. Time–motion analysis was used to document the movement patterns during an international field-hockey game. In addition, the movement patterns of repeated-sprint activity were investigated, as repeated-sprint ability is considered to be an important fitness component of team-sport performance. Fourteen members of the Australian men's field-hockey team (age 26±3 years, body mass 76.7±5.6?kg, [Vdot]O_2max 57.9±3.6?ml?·?kg^?1?·?min^?1; mean±s) were filmed during an international game and their movement patterns were analysed. The majority of the total player game time was spent in the low-intensity motions of walking, jogging and standing (46.5±8.1, 40.5±7.0 and 7.4±0.9%, respectively). In comparison, the proportions of time spent in striding and sprinting were 4.1±1.1 and 1.5±0.6%, respectively. Our criteria for ‘repeated-sprint’ activity (defined as a minimum of three sprints, with mean recovery duration between sprints of less than 21?s) was met on 17 occasions during the game (total for all players), with a mean 4±1 sprints per bout. On average, 95% of the recovery during the repeated-sprint bouts was of an active nature. In summary, the results suggest that the motion activities of an elite field-hockey competition are similar to those of elite soccer, rugby and Australian Rules football. In addition, the investigation of repeated-sprint activity during competition has provided additional information about the unique physiological demands of elite field-hockey performance.  相似文献   

Embedding with multiple knowledge sources to improve innovation performance: the learning experience of Motorola in Brazil     

Paulo N?FigueiredoEmail author 《知识管理研究与实践》2013,11(4):361-373

This article explores how a subsidiary of a multi-national enterprise (MNE) in an emerging economy embeds with multiple knowledge sources, both in its corporate network (internal) and in the host country (external), to create the capability to undertake innovative activities. Drawing on first-hand and intra-firm field evidence over the lifetime of a subsidiary in the information and communications technology industry in Brazil (1996–2009) the article finds that: (1) Within 10 years, the case subsidiary attained advanced, near-world leading innovation performance in three technological functions: project management, software engineering and product and solutions; (2) This was an outcome of how the firm simultaneously engaged in knowledge-intensive linkages based on increased frequency of use and improved quality over time, with specific internal and external counterparts; (3) However, some counterparts and linkages were more effective than others in contributing to the subsidiary's innovation performance. Drawing on a novel approach that examines the relationship between dual embeddedness and innovative performance, this article extends our understanding of embeddedness as part of knowledge-seeking strategies of MNE-subsidiaries. It also provides new insights to deepen the analysis of the nuances of subsidiaries’ multiple embeddedness, especially in emerging economies.  相似文献   

从墨家和平思想看中国和平发展战略的思想渊源与现代重构     

张丙辰  张岚  蒋文梅 《职大学报》2013,(5):10-14

中国和平发展战略思想是墨家及中国传统思想家朴素的和平思想的现代转型与重构,是马克思主义和平发展思想在当代的继承与发展.探究梳理墨家及中国传统文化中的和平思想精髓,对于继承和弘扬马克思主义和平发展思想精华,把握中国和平发展战略思想的意蕴要旨具有重要意义.  相似文献   

Relationships between cardiorespiratory fitness,inhibition, and math fluency: A cluster analysis     

Juan L. Núñez  Luis Mahbubani  Elisa Huéscar 《Journal of sports sciences》2013,31(23):2660-2666

ABSTRACT

This study identified clusters of adolescents who share similar cardiorespiratory fitness levels and analysed the relationships between cardiorespiratory fitness, inhibition, and math fluency in each of the clusters. The subjects were 490 high-school students aged 10–16 years. The mean age was 13.82 years (SD = 1.12). Latent class analysis identified three clusters with high, medium, and low levels of cardiorespiratory fitness. The high-fitness cluster achieved higher scores in inhibition and math fluency than the low-fitness cluster. Path analysis revealed that the influence of cardiorespiratory fitness on inhibition was non-existent in the three clusters. The effect of inhibition on math fluency was positive and significant in all three cardiorespiratory fitness levels. Cardiorespiratory fitness had a direct, positive, and significant effect on math fluency only in the high-fitness cluster. Therefore, a high level of cardiorespiratory fitness is a significant determining factor in the explanation of math fluency. These results indicate that inhibition does not mediate the relationship between cardiorespiratory fitness and math fluency. However, the benefits of cardiorespiratory fitness affect math fluency, which has important implications for the educational environment and the teaching/learning process.  相似文献   

Comment on ‘Ventilation and blood lactate increase exponentially during incremental exercise’ : A reply     

Steven C. Dennis  Timothy D. Noakes  Andrew N. Bosch 《Journal of sports sciences》2013,31(5):377-378

Oar force and oar angle data resulting from a 6‐min maximal rowing ergometer test undertaken by novice (n = 9), good (n ‐ 23) and national (n = 9) level male rowers, were used to identify biomechanical performance variables which accurately discriminated between rowers of differing ability levels. The variables included two work capacity measures, mean propulsive power output per kilogram of body mass (W kg^‐1) and propulsive work consistency (%), and two skill variables, stroke‐to‐stroke consistency (%) and stroke smoothness (%). Discriminant function analysis indicated the presence of two functions, both of which clearly indicated the importance of mean propulsive power output per kilogram of body mass as a discriminating variable. Function 2 gave greater weight to stroke‐to‐stroke consistency and stroke smoothness than function 1; however, function 1 was the most powerful discriminator. Classification procedures were used to predict the ability level to which a rower most likely belonged and involved defining the ‘distance’ between each rower and each ability level centroid, with the rower being classified into the ‘nearest’ ability level. These procedures indicated that 100% of the elite, 73.9% of the good, 88.9% of the novice and 82.9% of all rowers were correctly classified into their respective skill levels. Stepwise discriminant analysis included the variables in the following order: mean propulsive power output per kilogram of body mass, stroke‐to‐stroke consistency, stroke smoothness and propulsive work consistency (P < 0.001). The results of this study indicate that biomechanical performance variables related to rowing capacity and skill may be identified and used to discriminate accurately between rowers of differing skill levels, and that, of these variables, propulsive work consistency is the least effective discriminator.  相似文献