Influence of regression model and initial intensity of an incremental test on the relationship between the lactate threshold estimated by the maximal-deviation method and running performance     

Jordan Santos-Concejero  Ross Tucker  Cristina Granados  Jon Irazusta  Iraia Bidaurrazaga-Letona  Jon Zabala-Lili 《Journal of sports sciences》2013,31(9):853-859

Abstract

This study investigated the influence of the regression model and initial intensity during an incremental test on the relationship between the lactate threshold estimated by the maximal-deviation method and performance in elite-standard runners. Twenty-three well-trained runners completed a discontinuous incremental running test on a treadmill. Speed started at 9 km · h^?1 and increased by 1.5 km · h^?1 every 4 min until exhaustion, with a minute of recovery for blood collection. Lactate–speed data were fitted by exponential and polynomial models. The lactate threshold was determined for both models, using all the co-ordinates, excluding the first and excluding the first and second points. The exponential lactate threshold was greater than the polynomial equivalent in any co-ordinate condition (P < 0.001). For both models, the lactate threshold was lower when all co-ordinates were used than when the first and the first and second points were excluded (P < 0.001). 10-km race pace was correlated with both the exponential and polynomial lactate thresholds for all the co-ordinate conditions (r ≥ 0.75, P < 0.001 and r ≥ 0.56, P < 0.05, respectively). The results suggest that the exponential lactate threshold should be used instead of the polynomial equivalent since it is more strongly associated with performance and is independent of the initial intensity of the test.  相似文献   

The Dynamics of Leisure Motivation: The Effects of Outcome on Leisure Needs     

Seppo E. Iso-Ahola  Jon R. Allen 《Research quarterly for exercise and sport》2013,84(2):141-149

Abstract

Predicated upon the premise that leisure needs are socially determined and therefore dynamic qualities of leisure motivation, this field study investigated the effects of outcome (winning, losing, no outcome) of leisure participation on male and female subjects' leisure needs. Subjects were 438 players of 60 teams in the intramural basketball program comprised of competitive and recreational leagues. Factor analysis produced seven need factors, of which three dealt with interpersonal relationships, two with competence and two with escape or diversion. ANOVAs performed on the resultant factor scores showed that successful and unsuccessful leisure experiences strongly shaped subjects' needs for leisure participation, but these effects were often mediated by the sex of subjects and the competitive levels of leagues in which they played. Generally, winning and losing had just the opposite effects on males' and females' needs; winning increased females' and decreased males' needs. The effects of competitiveness of league types suggested that competitive and recreational leagues serve different psychological functions for males and females because the two leagues are expected to fulfill different leisure needs.  相似文献   

Comments on “democracy in an information society”: The difficulty of projecting impacts from trajectories of emerging technologies     

Jon A. Turner 《The Information Society》2013,29(1-2):53-63

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Is movement variability important for sports biomechanists?     

Roger Bartlett  Jon Wheat  Matthew Robins 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):224-243

This paper overviews the importance for sports biomechanics of movement variability, which has been studied for some time by cognitive and ecological motor skills specialists but, until quite recently, had somewhat been overlooked by sports biomechanists. The paper considers biomechanics research reporting inter- and intra-individual movement variability in javelin and discus throwing, basketball shooting, and locomotion. The overview does not claim to be comprehensive and we exclude such issues as the theoretical background to movement and coordination variability and their measurement. We overview evidence, both theoretical and empirical, of inter-individual movement variability in seeking to achieve the same task goal, in contrast to the concept of “optimal” movement patterns. Furthermore, even elite athletes cannot reproduce identical movement patterns after many years of training, contradicting the ideas of motor invariance and “representative” trials. We contend that movement variability, far from being solely due to neuromuscular system or measurement “noise” – as sports biomechanists may have previously supposed – is, or could be, functional. Such functionality could allow environmental adaptations, reduce injury risk, and facilitate changes in coordination patterns. We conclude by recommending that sports biomechanists should focus more of their research on movement variability and on important related topics, such as control and coordination of movement, and implications for practice and skill learning.  相似文献   

Major League Baseball and the Dominican Republic: What is in the best interest of the players?     

Adrien Bouchet  Michael Troilo  Jon Welty Peachey 《Sport Management Review》2013,16(2):236-250

This case is about Major League Baseball and the Dominican Republic. We explore how Major League Baseball has used this Caribbean island as an inexpensive labor market and the social problems of the situation. Specifically, we examine Corporate Social Responsibility, the leadership of Sandy Alderson, ethics and the various stakeholders involved. We also look into possible reform alternatives while addressing the central question: What is in the best interest of the players?  相似文献   

Towards a Collaborative Approach to Teacher Empowerment     

Vic Lally  Jon Scaefe 《British Educational Research Journal》1995,21(3):323-338

This paper outlines a project based on an approach to teacher empowerment through collaborative action research. Using accounts from teachers involved in the project, the conditions necessary for the development of collegiality on in-service courses are explored. The nature and significance of agenda setting and ways of introducing tools for empowerment are described. The use of collaborative autobiography (CA), interpersonal process recall (1PR) and a general supervisory framework (GSF) are analysed in detail. The paper concludes with comment on the extent to which teachers are empowered by these tools to reconstruct the complex relationships between power, knowledge, ideology and schooling which dominate much of their working lives.  相似文献   

‘Good books’: is there a future for academic writing within the educational publishing industry?     

Jon Nixon 《British Journal of Sociology of Education》2005,26(1):91-103

This paper draws on questionnaire responses received (via e‐mail) during the period 2002–2003 from senior commissioning editors located within seven of the major UK publishing outlets. Drawing on the analytical framework of an earlier study by Nixon (1999 Nixon, J. (1999). Teachers, writers, professionals. Is there anybody out there. British Journal of Sociology of Education, 20(2): 207–221. [Taylor & Francis Online], [Web of Science ®] [Google Scholar]), it focuses on the mediation of educational studies by market forces operating within and upon the educational publishing industry. More specifically it explores issues relating to the construction of readership, authorship and editorship within that force field of market pressures. Central to the argument is the claim that, in its increasing exposure to market forces, the public space afforded by educational publishing is now highly restrictive. The paper concludes with a call for a sustained debate on the future of academic publishing in general, and educational publishing in particular.  相似文献   

Learning to observe: using video to improve preservice mathematics teachers’ ability to notice     

Jon R. Star  Sharon K. Strickland 《Journal of Mathematics Teacher Education》2008,11(2):107-125

Video has assumed an increasingly prominent role in teacher education, particularly in the form of the viewing of videotaped class lessons by preservice teachers. Yet there is little research that confirms whether preservice teachers attend to the aspects of the video(s) that teacher educators anticipate or desire. This article explores this issue and reports on the impact of video viewing as a means to improve teachers’ ability to be observers of classroom practice. We utilized a pre- and post-test design to measure the quantity and type of classroom events that preservice mathematics teachers noticed before and after a teaching methods course where improving observation skills was an explicit goal. The results of the pre-assessment suggest that preservice teachers generally do not enter teaching methods courses with well-developed observation skills. The post-assessment indicates that the course led to significant increases in preservice teachers’ observation skills, particularly in teachers’ ability to notice features of the classroom environment, mathematical content of a lesson, and teacher and student communication during a lesson.

Jon R. StarEmail:

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Concerns about research and prevention strategies in Munchausen Syndrome by Proxy (MSBP) abuse     

Eminson M  Jureidini J 《Child abuse & neglect》2003,27(4):413-420

There would seem to be three motives for research into Munchausen Syndrome by Proxy (MSBP) abuse; first to enhance treatment; second to enhance our understanding of the psychopathology of those who carry out the abuse; and third to find interventions to prevent its occurrence. We will argue that only the first justification is valid. The second and third should be questioned for several reasons including: MSBP abuse is the wrong kind of event to think of in terms of categorical diagnosis; rare events are inherently difficult to predict; and better research targets are available. We propose that research energy would be more productively directed towards furthering our understanding of somatization and certain problematic aspects of modern pediatric practice. We offer suggestions as to appropriate areas for research.  相似文献   

The Virtual Field Station (VFS): using a virtual reality environment for ecological fieldwork in A-Level biological studies—Case Study 3     

Roger Poland  Linda Baggott la Velle  Jon Nichol 《British journal of educational technology : journal of the Council for Educational Technology》2003,34(2):215-231

Case studies are one way of producing the evidential base necessary for ICT to become embedded in everyday teaching and learning. Such case studies are vital for the purposes of generalisation. Also, teacher generated case-studies have the benefit of being research that is done by teachers in conjunction with Higher Education support and mediation, as opposed to research being done to teachers by Higher Education. One such teacher-generated case study at the cutting edge of ICT researches the effectiveness of a Virtual Field Station for the teaching of an A Level biology topic. The subject was the exotic one of the Mediterranean sea turtle. Student fieldwork involving these fascinating creatures is desirable but difficult, as the sea turtle's habitat is the archipelago of the Aegean Sea. The paper argues that a Virtual Field Centre is an effective substitute for actuality in terms of the development of student knowledge and understanding for examination purposes. As such, it is an innovative development that sits at the forefront of an area of Science Education that is rapidly developing, ie ICT-mediated teaching and learning.  相似文献