In order to apply the LM device previously developed to precisely measuring small motion trajectories located on the different motion planes, three major improvements are successfully performed under the condition of ...In order to apply the LM device previously developed to precisely measuring small motion trajectories located on the different motion planes, three major improvements are successfully performed under the condition of completely maintaining the advantages of the device. These improvements include 1) development of a novel connection mechanism to smoothly attach the device to the spindle of a machining centre;2) employment of a new data sampling method to achieve a high sampling frequency independent of the operating system of the control computer;and 3) proposal of a set-up method to conveniently install the device on the test machining centre with respect to different motion planes. Practical measurement experiment results with the improved device on a machining centre sufficiently demonstrate the effectiveness of the improvements and confirm several features including a very good response to small displacement close to the resolution of the device, high precision, repeatability and reliance. Moreover, based on the measurement results for a number of trajectories for a wide range of motion conditions, the error characteristics of small size motions are systematically discussed and the effect of the movement size and feed rate on the motion accuracy is verified for the machining centre tested.展开更多
As cloud computing usage grows,cloud data centers play an increasingly important role.To maximize resource utilization,ensure service quality,and enhance system performance,it is crucial to allocate tasks and manage p...As cloud computing usage grows,cloud data centers play an increasingly important role.To maximize resource utilization,ensure service quality,and enhance system performance,it is crucial to allocate tasks and manage performance effectively.The purpose of this study is to provide an extensive analysis of task allocation and performance management techniques employed in cloud data centers.The aim is to systematically categorize and organize previous research by identifying the cloud computing methodologies,categories,and gaps.A literature review was conducted,which included the analysis of 463 task allocations and 480 performance management papers.The review revealed three task allocation research topics and seven performance management methods.Task allocation research areas are resource allocation,load-Balancing,and scheduling.Performance management includes monitoring and control,power and energy management,resource utilization optimization,quality of service management,fault management,virtual machine management,and network management.The study proposes new techniques to enhance cloud computing work allocation and performance management.Short-comings in each approach can guide future research.The research’s findings on cloud data center task allocation and performance management can assist academics,practitioners,and cloud service providers in optimizing their systems for dependability,cost-effectiveness,and scalability.Innovative methodologies can steer future research to fill gaps in the literature.展开更多
Assessment of performance of China's sports industry is not only favorable for grasping development level of sports industry,but also able to,from micro perspective,find out factors influencing development of spor...Assessment of performance of China's sports industry is not only favorable for grasping development level of sports industry,but also able to,from micro perspective,find out factors influencing development of sports industry and their contribution to development of sports industry. Through selecting quantitative indicators for development of sports industry,the authors analyzed performance of development of sports industry in China and analyzed regional difference of sports industry by the data envelopment analysis( DEA) method. The study indicated that( i) performance of sports industry in recent years takes on growth trend,which may give the credit to scientific and technological progress;( ii) the development of sports industry in China has distinct spatial difference,best in eastern regions,better in middle regions,and poor in western regions.展开更多
Evaluating and selecting players to suit football clubs and decision-makers (coaches, managers, technical, and medical staff) is a difficult process from a managerial-financial and sporting perspective. Football is a ...Evaluating and selecting players to suit football clubs and decision-makers (coaches, managers, technical, and medical staff) is a difficult process from a managerial-financial and sporting perspective. Football is a highly competitive sport where sponsors and fans are attracted by success. The most successful players, based on their characteristics (criteria and sub-criteria), can influence the outcome of a football game at any given time. Consequently, the D-day of selection should employ a more appropriate approach to human resource management. To effectively address this issue, a detailed study and analysis of the available literature are needed to assist practitioners and professionals in making decisions about football player selection and hiring. Peer-reviewed journals were selected for collecting published papers between 2018 and 2023. A total of 66 relevant articles (journal articles, conference articles, book sections, and review articles) were selected for evaluation and analysis. The purpose of the study is to present a systematic literature review (SLR) on how to solve this problem and organize the published research papers that answer our four research questions.展开更多
Background: In recent years, there has been a proliferation of technology and sport science utilized within an athlete's training, especially at the elite level. However, the sport science is a broad field, encompas...Background: In recent years, there has been a proliferation of technology and sport science utilized within an athlete's training, especially at the elite level. However, the sport science is a broad field, encompassing disciplines such as biomechanics, motor control and learning, exercise physiology, sports medicine, sport psychology to name a few. Rarely are these disciplines applied in an integrated manner. The purpose of this study was to document the effectiveness of an integrated biomechanics and motor control protocol for improving athlete's performance in the high jump. Methods: Four elite high jumpers performed baseline jumps under no^mal conditions and then jumps using a specific external focus of attention cue designed to improve their running posture. Three-dimensional biomeehanical analysis was used to quantify the upright posture throughout the approach as well as horizontal velocity at plant and vertical velocity at takeoff. Results: The results showed that when using the external focus of attention cue, the jumpers were significantly more upright during the approach, had significantly higher horizontal velocities at plant, and generated significantly greater vertical velocities during the takeoff. Conclusion: The results of this study lay the foundation for future work examining how integrating sport science disciplines can improve performance of elite level athletes.展开更多
With the Rio Olympics just a few months past,we remember the excitement,the incredible performances,and the controversies.As happens so often,the Olympic Games focus attention not only on athletic achievements but als...With the Rio Olympics just a few months past,we remember the excitement,the incredible performances,and the controversies.As happens so often,the Olympic Games focus attention not only on athletic achievements but also on how athletes may reach ever-increasing levels of performance.Doping,medical展开更多
Two customized mouthguards were developed for a 35-year-old male kickboxer. These were identical in thickness (the vertical dimension between the upper and lower jaws), the material, and similar in form (visible outli...Two customized mouthguards were developed for a 35-year-old male kickboxer. These were identical in thickness (the vertical dimension between the upper and lower jaws), the material, and similar in form (visible outline);however, one mouthguard was designed such that the horizontal jaw position was determined by the maximal grip strength obtained by the subject during the Bi-Digital O-Ring Test. Both mouthguards were satisfactory in terms of how they felt during wearing and breathing;however, the subject achieved higher kicking force, punching force, and back muscle strength while using the mouthguard with an optimized horizontal jaw position. These findings suggest that to enhance sports performance, it may be important to determine the optimal biting position. The grip strength obtained during the Bi-Digital O-Ring Test is a useful parameter for this assessment.展开更多
Aiming at the problems in reality, this paper makes a systematic analysis based on the investigation and research on the current situation of the sports resources in public sports service of Changzhou University, from...Aiming at the problems in reality, this paper makes a systematic analysis based on the investigation and research on the current situation of the sports resources in public sports service of Changzhou University, from the aspects of public sports service system, facilities planning and social sports industrialization. In order to connecting the school's physical education and public sports services as seamlessly as possible, it becomes a union for the coordination with each other, and provides the national fitness campaign with rapid and healthy conditions.展开更多
This paper introduces the third party performance evaluation in the construction of demonstration area for modem public sports services in Changzhou through research methods such as literature, expert interview and ca...This paper introduces the third party performance evaluation in the construction of demonstration area for modem public sports services in Changzhou through research methods such as literature, expert interview and case study, so as to promote the quality of demonstration area constructed for modem public sports services, truly show the social application value of the construction of demonstration area for modem public sports services, and achieve national fitness and the development of public sports.展开更多
Since 2006, the public corporations in China are required to include its social responsibilities in its annual report by company law. Corporations’ business activities should not only focus on maximizing its economic...Since 2006, the public corporations in China are required to include its social responsibilities in its annual report by company law. Corporations’ business activities should not only focus on maximizing its economic profit but also serve the society. With the awareness of the importance of social responsibility, there are an increasing number of public corporations in China to undertake more charitable activities or employee training activities. There have been a lot of academic researches investigating the relationship between corporate social responsibilities and corporate financial performance. However, the results are inconsistent and vary according to different industries. This study chose Chinese culture, sports and entertainment industry as a sample to test the relationship between CSR and corporate financial performance. Four financial ratios were used to test whether the caproate’s reasonability to government, employee, investors and society has significant impact on its financial performance. The empirical results show that apart from the responsibility to employees which is negatively influence the corporate financial performance the other three factors are found not significantly influence corporate financial performance.展开更多
为系统梳理国际体育科学领域“performance”的概念、学科与热点,以“Web of ScienceTM”数据库2000—2021年47546篇相关文献为数据来源,采用Citespace、Vosviewer等工具进行文献计量分析。结果表明:(1)“performance”研究对象是“运...为系统梳理国际体育科学领域“performance”的概念、学科与热点,以“Web of ScienceTM”数据库2000—2021年47546篇相关文献为数据来源,采用Citespace、Vosviewer等工具进行文献计量分析。结果表明:(1)“performance”研究对象是“运动中的人”,研究内容主要为运动员竞技表现提升、非运动员的健康促进和运动员/非运动员的损伤康复等;(2)“performance”相关研究围绕“运动中人的表现”,涉及生理学视角下运动与训练,生物力学和康复学视角下损伤与康复,心理学视角下技能学习、运动表现和健康促进,力量和爆发力训练,团队项目体能和技战术表现与分析5个领域;(3)广义的“performance”涉及竞技表现、健康促进和损伤康复3个领域,狭义的“performance”专指竞技表现。展开更多
Ischemic preconditioning(IPC)is an attractive method for athletes owing to its potential to enhance exercise performance.However,the effectiveness of the IPC intervention in the field of sports science remains mitigat...Ischemic preconditioning(IPC)is an attractive method for athletes owing to its potential to enhance exercise performance.However,the effectiveness of the IPC intervention in the field of sports science remains mitigated.The number of cycles of ischemia and reperfusion,as well as the duration of the cycle,varies from one study to another;Thus,the aim of this systematic review was to provide a comprehensive review examining the IPC literature in sports science.A systematic literature search was performed in PubMed(MEDLINE)(from 1946 to May 2018),Web of Science(sport sciences)(from 1945 to May 2018),and EMBASE(from 1974 to May 2018).We included all studies investigating the effects of IPC on exercise performance in human subjects.To assess scientific evidence for each study,this review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.The electronic database search generated 441 potential articles that were screened for eligibility.A total of 52 studies were identified as eligible and valid for this systematic review.The studies included were of high quality,with 48 of the 52 studies having a ran?domized,controlled trial design.Most studied showed that IPC intervention can be beneficial to exercise performance.However,IPC intervention seems to be more beneficial to healthy subjects who wish to enhance their performance in aerobic exercises than athletes.Thus,this systematic review highlights that a better knowledge of the mechanisms generated by the IPC intervention would make it possible to optimize the protocols according to the characteristics of the subjects with the aim of suggesting to the subjects the best possible experience of IPC intervention.展开更多
Background: Pacing, defined as percentage changes of speed between successive splits, has been extensively studied in running and cycling endurance sports; however, less information about the trends in change of spee...Background: Pacing, defined as percentage changes of speed between successive splits, has been extensively studied in running and cycling endurance sports; however, less information about the trends in change of speed during cross-country (XC) ski racing is available. Therefore, the aim of the present study was to examine the effect of performance (quartiles of race time (Q), with Q1 the fastest and Q4 the slowest) level on pacing in the Vasaloppet ski race, the largest XC skiing race in the world. Methods: For this purpose, we analyzed female (n = 19,465) and male (n = 164,454) finishers in the Vasaloppet ski race from 2004 to 2017 using a one-way (2 sexes) analysis of variance with repeated measures to examine percentage changes of speed between 2 successive splits. Overall, the race consisted of 8 splits. Results: The race speeds of Q1, Q2, Q3, and Q4 were 13.6 ± 1.8, 10.6 ± 0.5, 9.2 ± 0.3, and 8.1 ±- 0.4 km/h, respectively, among females and 16.7 ± 1.7, 13.1 ± 0.7, 10.9 ± 0.6, and 8.9 ± 0.7 km/h, respectively, among males. The overall pacing strategy of finishers was variable. A small sex × split interaction on speed was observed (η^2= 0.016, p 〈 0.001), with speed difference between sexes ranging from 14.9% (Split 7) to 27.0% (Split 1) and larger changes in speed between 2 successive splits being shown for females (p 〈 0.001, η^2=0.004). A large performance × split interaction on speed, with Q1 presenting the smallest changes of speed between splits, was shown for females (η^2= 0.149, p 〈 0.001) and males (η^2 = 0.169,p 〈 0.001). Conclusion: Male and fast XC skiers are more even pacers. Coaches and athletes should develop tailored sex- and performance-level pacing strategies; for instance, they should advise fast XC skiers to start fast and maintain their speed, rather than starting slowly and trying to make up time by going faster at times during the race.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/).展开更多
Purpose:This study investigated emotion-performance relationships in rugby union.We identified which emotions rugby players experienced and the extent to which these emotions were associated with performance,consideri...Purpose:This study investigated emotion-performance relationships in rugby union.We identified which emotions rugby players experienced and the extent to which these emotions were associated with performance,considering how emotions unfold over the course of a game,and whether the game was played at home or away.Methods:Data were gathered from 22 professional male rugby union players using auto-confrontation interviews to help identify situations within games when players experienced intense emotions.We assessed the intensity of emotions experienced before each discrete performance and therefore could assess the emotion-performance relationship within a competition.Results:Players identified experiencing intense emotions at 189 time-points.Experts in rugby union rated the quality of each performance at these 189 time-points on a visual analog scale.A Linear Mixed Effects model to investigate emotion-performance relationships found additive effects of game location,game time,and emotions on individual performance.Conclusion:Results showed 7 different pre-performance emotions,with high anxiety and anger associating with poor performance.Future research should continue to investigate emotion-performance relationships during performance using video-assisted recall and use a measure of performance that has face validity for players and coaches alike.展开更多
Purpose: The aim of the present study is to examine the performance of young Japanese cross-country skiers of different competitive levels with the use of Yo-Yo tests and the 12-minute run test (12MRT) that have been ...Purpose: The aim of the present study is to examine the performance of young Japanese cross-country skiers of different competitive levels with the use of Yo-Yo tests and the 12-minute run test (12MRT) that have been demonstrated to be related to each level, and to know which test is suitable for different competitive performance. Methods: Elite group (N = 9) was 16.9 ± 0.3 years and moderate trained group (N = 22) was 16.1 ± 0.9 years. The testing sessions consisted of the following: 1) Vertical jump and 50m sprint;2) the Yo-Yo tests level 1 and 2 (intermittent recovery);3) 12MRT. Results: Results showed the vertical jump heights and 50m sprint that no significant both performances differences were found among the two groups. Significant the Yo-Yo tests and 12MRT performances differences were found between the two groups (p < 0.05). Performance test (%) showed the ratio of moderate trained group towards elite group. The Yo-Yo tests performance was low enough compared with the result of 12MRT in moderate trained group. Conclusions: It is therefore valid to assume that low Yo-Yo tests performance due to immature anaerobic in cross-country skiers was a new limiting factor in the competitive level.展开更多
Le Parkour is a sport where the athletes transpose common day-to-day obstacles in the best possible way. This sport demands elements like strength, focus and decision making;elements supposedly affected by energy drin...Le Parkour is a sport where the athletes transpose common day-to-day obstacles in the best possible way. This sport demands elements like strength, focus and decision making;elements supposedly affected by energy drinks, with performance improvement. The aim of this study was to investigate the effects of energy drink ingestion on Le Parkour athlete’s performance. Twelve male amateur athletes, mean age of 23.5 ± 2.74, took part in this randomized, double-blind, placebocontrolled study. Subjects were randomly assigned to drink: 250 ml of energy drink, 500 ml of energy drink or placebo. Forty minutes after the beverage consumption, they were evaluated in a specific circuit performance test (time to complete the circuit) followed by a perceived exertion and a circuit technical difficulty evaluation. We also evaluated heart rate in 3 different moments: rest, pre-circuit and post-circuit. All variables were collected in 3 different experimental days. Time, perceived exertion and technical difficulty were higher in the first day compared to the others. Heart rate did not show a difference when we compared the days. Drinking one or two cans of an energy drink did not improve performance of Le Parkour athletes in a sport specific test. It also did not change heart rate or perceived exertion.展开更多
目的:综述前人研究成果,客观呈现抗阻训练对运动表现的影响以及这种影响背后的实现通路,为后续抗阻训练的研究提供一定的参考。方法:在Web of science核心合集数据库、Pubmed、中国知网等数据库中以“resistance training”“sports per...目的:综述前人研究成果,客观呈现抗阻训练对运动表现的影响以及这种影响背后的实现通路,为后续抗阻训练的研究提供一定的参考。方法:在Web of science核心合集数据库、Pubmed、中国知网等数据库中以“resistance training”“sports performance”“mechanism of action”为关键词进行检索,对检索出文献中不符合的内容以及重复发表的文献进行剔除,最后共获得有效参考文献47篇。结果:(1)抗阻训练使受试者力量、速度、耐力得到了显著提升,而注意力以及执行功能则略有改善。(2)抗阻训练创新点在于如何控制训练的强度及容量,从训练效益方面来说,通常训练强度与量度成反比。(3)抗阻训练所带来的适应性及其所涉及的生物学机制包括了肌蛋白浓度变化以及蛋白结合通路改变;脑波增强、运动神经元更加活跃;睾酮/皮质醇浓度变化。结论:抗阻训练对运动表现所带来的影响利大于弊,但过激的训练负荷可能也会带来一定的伤病隐患,因此在针对不同训练群体时,应在保证安全的前提下,以较小的幅度增加负荷的重量以刺激机体更快地适应,促进后续运动表现得到更好、更快地提升。展开更多
文摘In order to apply the LM device previously developed to precisely measuring small motion trajectories located on the different motion planes, three major improvements are successfully performed under the condition of completely maintaining the advantages of the device. These improvements include 1) development of a novel connection mechanism to smoothly attach the device to the spindle of a machining centre;2) employment of a new data sampling method to achieve a high sampling frequency independent of the operating system of the control computer;and 3) proposal of a set-up method to conveniently install the device on the test machining centre with respect to different motion planes. Practical measurement experiment results with the improved device on a machining centre sufficiently demonstrate the effectiveness of the improvements and confirm several features including a very good response to small displacement close to the resolution of the device, high precision, repeatability and reliance. Moreover, based on the measurement results for a number of trajectories for a wide range of motion conditions, the error characteristics of small size motions are systematically discussed and the effect of the movement size and feed rate on the motion accuracy is verified for the machining centre tested.
基金supported by the Ministerio Espanol de Ciencia e Innovación under Project Number PID2020-115570GB-C22,MCIN/AEI/10.13039/501100011033by the Cátedra de Empresa Tecnología para las Personas(UGR-Fujitsu).
文摘As cloud computing usage grows,cloud data centers play an increasingly important role.To maximize resource utilization,ensure service quality,and enhance system performance,it is crucial to allocate tasks and manage performance effectively.The purpose of this study is to provide an extensive analysis of task allocation and performance management techniques employed in cloud data centers.The aim is to systematically categorize and organize previous research by identifying the cloud computing methodologies,categories,and gaps.A literature review was conducted,which included the analysis of 463 task allocations and 480 performance management papers.The review revealed three task allocation research topics and seven performance management methods.Task allocation research areas are resource allocation,load-Balancing,and scheduling.Performance management includes monitoring and control,power and energy management,resource utilization optimization,quality of service management,fault management,virtual machine management,and network management.The study proposes new techniques to enhance cloud computing work allocation and performance management.Short-comings in each approach can guide future research.The research’s findings on cloud data center task allocation and performance management can assist academics,practitioners,and cloud service providers in optimizing their systems for dependability,cost-effectiveness,and scalability.Innovative methodologies can steer future research to fill gaps in the literature.
文摘Assessment of performance of China's sports industry is not only favorable for grasping development level of sports industry,but also able to,from micro perspective,find out factors influencing development of sports industry and their contribution to development of sports industry. Through selecting quantitative indicators for development of sports industry,the authors analyzed performance of development of sports industry in China and analyzed regional difference of sports industry by the data envelopment analysis( DEA) method. The study indicated that( i) performance of sports industry in recent years takes on growth trend,which may give the credit to scientific and technological progress;( ii) the development of sports industry in China has distinct spatial difference,best in eastern regions,better in middle regions,and poor in western regions.
文摘Evaluating and selecting players to suit football clubs and decision-makers (coaches, managers, technical, and medical staff) is a difficult process from a managerial-financial and sporting perspective. Football is a highly competitive sport where sponsors and fans are attracted by success. The most successful players, based on their characteristics (criteria and sub-criteria), can influence the outcome of a football game at any given time. Consequently, the D-day of selection should employ a more appropriate approach to human resource management. To effectively address this issue, a detailed study and analysis of the available literature are needed to assist practitioners and professionals in making decisions about football player selection and hiring. Peer-reviewed journals were selected for collecting published papers between 2018 and 2023. A total of 66 relevant articles (journal articles, conference articles, book sections, and review articles) were selected for evaluation and analysis. The purpose of the study is to present a systematic literature review (SLR) on how to solve this problem and organize the published research papers that answer our four research questions.
文摘Background: In recent years, there has been a proliferation of technology and sport science utilized within an athlete's training, especially at the elite level. However, the sport science is a broad field, encompassing disciplines such as biomechanics, motor control and learning, exercise physiology, sports medicine, sport psychology to name a few. Rarely are these disciplines applied in an integrated manner. The purpose of this study was to document the effectiveness of an integrated biomechanics and motor control protocol for improving athlete's performance in the high jump. Methods: Four elite high jumpers performed baseline jumps under no^mal conditions and then jumps using a specific external focus of attention cue designed to improve their running posture. Three-dimensional biomeehanical analysis was used to quantify the upright posture throughout the approach as well as horizontal velocity at plant and vertical velocity at takeoff. Results: The results showed that when using the external focus of attention cue, the jumpers were significantly more upright during the approach, had significantly higher horizontal velocities at plant, and generated significantly greater vertical velocities during the takeoff. Conclusion: The results of this study lay the foundation for future work examining how integrating sport science disciplines can improve performance of elite level athletes.
文摘With the Rio Olympics just a few months past,we remember the excitement,the incredible performances,and the controversies.As happens so often,the Olympic Games focus attention not only on athletic achievements but also on how athletes may reach ever-increasing levels of performance.Doping,medical
文摘Two customized mouthguards were developed for a 35-year-old male kickboxer. These were identical in thickness (the vertical dimension between the upper and lower jaws), the material, and similar in form (visible outline);however, one mouthguard was designed such that the horizontal jaw position was determined by the maximal grip strength obtained by the subject during the Bi-Digital O-Ring Test. Both mouthguards were satisfactory in terms of how they felt during wearing and breathing;however, the subject achieved higher kicking force, punching force, and back muscle strength while using the mouthguard with an optimized horizontal jaw position. These findings suggest that to enhance sports performance, it may be important to determine the optimal biting position. The grip strength obtained during the Bi-Digital O-Ring Test is a useful parameter for this assessment.
文摘Aiming at the problems in reality, this paper makes a systematic analysis based on the investigation and research on the current situation of the sports resources in public sports service of Changzhou University, from the aspects of public sports service system, facilities planning and social sports industrialization. In order to connecting the school's physical education and public sports services as seamlessly as possible, it becomes a union for the coordination with each other, and provides the national fitness campaign with rapid and healthy conditions.
文摘This paper introduces the third party performance evaluation in the construction of demonstration area for modem public sports services in Changzhou through research methods such as literature, expert interview and case study, so as to promote the quality of demonstration area constructed for modem public sports services, truly show the social application value of the construction of demonstration area for modem public sports services, and achieve national fitness and the development of public sports.
文摘Since 2006, the public corporations in China are required to include its social responsibilities in its annual report by company law. Corporations’ business activities should not only focus on maximizing its economic profit but also serve the society. With the awareness of the importance of social responsibility, there are an increasing number of public corporations in China to undertake more charitable activities or employee training activities. There have been a lot of academic researches investigating the relationship between corporate social responsibilities and corporate financial performance. However, the results are inconsistent and vary according to different industries. This study chose Chinese culture, sports and entertainment industry as a sample to test the relationship between CSR and corporate financial performance. Four financial ratios were used to test whether the caproate’s reasonability to government, employee, investors and society has significant impact on its financial performance. The empirical results show that apart from the responsibility to employees which is negatively influence the corporate financial performance the other three factors are found not significantly influence corporate financial performance.
文摘为系统梳理国际体育科学领域“performance”的概念、学科与热点,以“Web of ScienceTM”数据库2000—2021年47546篇相关文献为数据来源,采用Citespace、Vosviewer等工具进行文献计量分析。结果表明:(1)“performance”研究对象是“运动中的人”,研究内容主要为运动员竞技表现提升、非运动员的健康促进和运动员/非运动员的损伤康复等;(2)“performance”相关研究围绕“运动中人的表现”,涉及生理学视角下运动与训练,生物力学和康复学视角下损伤与康复,心理学视角下技能学习、运动表现和健康促进,力量和爆发力训练,团队项目体能和技战术表现与分析5个领域;(3)广义的“performance”涉及竞技表现、健康促进和损伤康复3个领域,狭义的“performance”专指竞技表现。
文摘Ischemic preconditioning(IPC)is an attractive method for athletes owing to its potential to enhance exercise performance.However,the effectiveness of the IPC intervention in the field of sports science remains mitigated.The number of cycles of ischemia and reperfusion,as well as the duration of the cycle,varies from one study to another;Thus,the aim of this systematic review was to provide a comprehensive review examining the IPC literature in sports science.A systematic literature search was performed in PubMed(MEDLINE)(from 1946 to May 2018),Web of Science(sport sciences)(from 1945 to May 2018),and EMBASE(from 1974 to May 2018).We included all studies investigating the effects of IPC on exercise performance in human subjects.To assess scientific evidence for each study,this review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.The electronic database search generated 441 potential articles that were screened for eligibility.A total of 52 studies were identified as eligible and valid for this systematic review.The studies included were of high quality,with 48 of the 52 studies having a ran?domized,controlled trial design.Most studied showed that IPC intervention can be beneficial to exercise performance.However,IPC intervention seems to be more beneficial to healthy subjects who wish to enhance their performance in aerobic exercises than athletes.Thus,this systematic review highlights that a better knowledge of the mechanisms generated by the IPC intervention would make it possible to optimize the protocols according to the characteristics of the subjects with the aim of suggesting to the subjects the best possible experience of IPC intervention.
文摘Background: Pacing, defined as percentage changes of speed between successive splits, has been extensively studied in running and cycling endurance sports; however, less information about the trends in change of speed during cross-country (XC) ski racing is available. Therefore, the aim of the present study was to examine the effect of performance (quartiles of race time (Q), with Q1 the fastest and Q4 the slowest) level on pacing in the Vasaloppet ski race, the largest XC skiing race in the world. Methods: For this purpose, we analyzed female (n = 19,465) and male (n = 164,454) finishers in the Vasaloppet ski race from 2004 to 2017 using a one-way (2 sexes) analysis of variance with repeated measures to examine percentage changes of speed between 2 successive splits. Overall, the race consisted of 8 splits. Results: The race speeds of Q1, Q2, Q3, and Q4 were 13.6 ± 1.8, 10.6 ± 0.5, 9.2 ± 0.3, and 8.1 ±- 0.4 km/h, respectively, among females and 16.7 ± 1.7, 13.1 ± 0.7, 10.9 ± 0.6, and 8.9 ± 0.7 km/h, respectively, among males. The overall pacing strategy of finishers was variable. A small sex × split interaction on speed was observed (η^2= 0.016, p 〈 0.001), with speed difference between sexes ranging from 14.9% (Split 7) to 27.0% (Split 1) and larger changes in speed between 2 successive splits being shown for females (p 〈 0.001, η^2=0.004). A large performance × split interaction on speed, with Q1 presenting the smallest changes of speed between splits, was shown for females (η^2= 0.149, p 〈 0.001) and males (η^2 = 0.169,p 〈 0.001). Conclusion: Male and fast XC skiers are more even pacers. Coaches and athletes should develop tailored sex- and performance-level pacing strategies; for instance, they should advise fast XC skiers to start fast and maintain their speed, rather than starting slowly and trying to make up time by going faster at times during the race.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/).
文摘Purpose:This study investigated emotion-performance relationships in rugby union.We identified which emotions rugby players experienced and the extent to which these emotions were associated with performance,considering how emotions unfold over the course of a game,and whether the game was played at home or away.Methods:Data were gathered from 22 professional male rugby union players using auto-confrontation interviews to help identify situations within games when players experienced intense emotions.We assessed the intensity of emotions experienced before each discrete performance and therefore could assess the emotion-performance relationship within a competition.Results:Players identified experiencing intense emotions at 189 time-points.Experts in rugby union rated the quality of each performance at these 189 time-points on a visual analog scale.A Linear Mixed Effects model to investigate emotion-performance relationships found additive effects of game location,game time,and emotions on individual performance.Conclusion:Results showed 7 different pre-performance emotions,with high anxiety and anger associating with poor performance.Future research should continue to investigate emotion-performance relationships during performance using video-assisted recall and use a measure of performance that has face validity for players and coaches alike.
文摘Purpose: The aim of the present study is to examine the performance of young Japanese cross-country skiers of different competitive levels with the use of Yo-Yo tests and the 12-minute run test (12MRT) that have been demonstrated to be related to each level, and to know which test is suitable for different competitive performance. Methods: Elite group (N = 9) was 16.9 ± 0.3 years and moderate trained group (N = 22) was 16.1 ± 0.9 years. The testing sessions consisted of the following: 1) Vertical jump and 50m sprint;2) the Yo-Yo tests level 1 and 2 (intermittent recovery);3) 12MRT. Results: Results showed the vertical jump heights and 50m sprint that no significant both performances differences were found among the two groups. Significant the Yo-Yo tests and 12MRT performances differences were found between the two groups (p < 0.05). Performance test (%) showed the ratio of moderate trained group towards elite group. The Yo-Yo tests performance was low enough compared with the result of 12MRT in moderate trained group. Conclusions: It is therefore valid to assume that low Yo-Yo tests performance due to immature anaerobic in cross-country skiers was a new limiting factor in the competitive level.
文摘Le Parkour is a sport where the athletes transpose common day-to-day obstacles in the best possible way. This sport demands elements like strength, focus and decision making;elements supposedly affected by energy drinks, with performance improvement. The aim of this study was to investigate the effects of energy drink ingestion on Le Parkour athlete’s performance. Twelve male amateur athletes, mean age of 23.5 ± 2.74, took part in this randomized, double-blind, placebocontrolled study. Subjects were randomly assigned to drink: 250 ml of energy drink, 500 ml of energy drink or placebo. Forty minutes after the beverage consumption, they were evaluated in a specific circuit performance test (time to complete the circuit) followed by a perceived exertion and a circuit technical difficulty evaluation. We also evaluated heart rate in 3 different moments: rest, pre-circuit and post-circuit. All variables were collected in 3 different experimental days. Time, perceived exertion and technical difficulty were higher in the first day compared to the others. Heart rate did not show a difference when we compared the days. Drinking one or two cans of an energy drink did not improve performance of Le Parkour athletes in a sport specific test. It also did not change heart rate or perceived exertion.
文摘目的:综述前人研究成果,客观呈现抗阻训练对运动表现的影响以及这种影响背后的实现通路,为后续抗阻训练的研究提供一定的参考。方法:在Web of science核心合集数据库、Pubmed、中国知网等数据库中以“resistance training”“sports performance”“mechanism of action”为关键词进行检索,对检索出文献中不符合的内容以及重复发表的文献进行剔除,最后共获得有效参考文献47篇。结果:(1)抗阻训练使受试者力量、速度、耐力得到了显著提升,而注意力以及执行功能则略有改善。(2)抗阻训练创新点在于如何控制训练的强度及容量,从训练效益方面来说,通常训练强度与量度成反比。(3)抗阻训练所带来的适应性及其所涉及的生物学机制包括了肌蛋白浓度变化以及蛋白结合通路改变;脑波增强、运动神经元更加活跃;睾酮/皮质醇浓度变化。结论:抗阻训练对运动表现所带来的影响利大于弊,但过激的训练负荷可能也会带来一定的伤病隐患,因此在针对不同训练群体时,应在保证安全的前提下,以较小的幅度增加负荷的重量以刺激机体更快地适应,促进后续运动表现得到更好、更快地提升。