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The effects of changing pace on metabolism and stroke characteristics during high-speed breaststroke swimming 总被引:1,自引:0,他引:1
Performances often vary between the heats and finals of breaststroke swimming competitions possibly because the swimmers try to conserve their energy, or for other tactical reasons. Additionally, coaches might advise either a 'positive' or 'even' pace race strategy during the final. The effect of such pacing changes on metabolism (blood lactate, heart rate, ventilation), ratings of perceived exertion, stroke kinematics and turning times have not been investigated. Nine male competitive breaststroke swimmers swam three paced (Aquapacer) 200-m trials, 48 h apart and in random order, at 98%, 100% and at an attempted 102% of their maximal 200-m time-trial speed. Responses in metabolic variables were similar between the 98% and 100% trials, but higher post-exercise blood lactate concentrations and respiratory exchange ratios were observed following the 102% trial. As the pace of trials increased, stroke rate was found to increase proportionately with stroke count. However, during the latter stages of the 100% trial, a disproportionate increase in the stroke count was observed, which led to a significant pacing error. This feature was more obvious in the 102% trial, where participants demonstrated 'positive pacing' and reported higher ratings of perceived exertion than for the 98% trial. During the early stages of the trials, turning times were initially shorter the faster the pace of the trial; however, as the trials progressed, this pattern was found to reverse. We conclude that a slight reduction in pace during near maximal breaststroke swimming altered kinematic but not post-exercise metabolic responses, while an increase in pace led to positive pacing and an increase in both kinematic responses and anaerobic metabolism. 相似文献
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Keating L Carter H Darwent M Bateman S Mackay DM Pullinger R 《Health information and libraries journal》2004,21(Z1):46-51
This article describes a working partnership between the Cairns Clinical Librarian Service, Health Care Libraries, University of Oxford and the Emergency Department (ED) at the John Radcliffe Hospital, Oxford. This collaboration resulted in the establishment of a guideline development group in June 2002. The aim of the group is to produce a set of easily accessible, user-orientated, evidence-based guidelines for the use of clinicians in the Emergency Department, within a realistic timescale. The Cairns Clinical Librarian Project was built on previous models of clinical librarianship and incorporated an evaluation of previous programmes. The objective was to provide information to clinicians at the time and point of need. Consultation with the ED from the outset determined the approach adopted by the Cairns team. Clinical guidelines have been shown to improve clinical practice. Pending the introduction of nationally available protocols, we have begun to establish a collection of evidence-based guidelines using web-based architecture in conjunction with the Oxford Radcliffe Hospitals NHS Trust's IT department. A piece of diagnostic analysis was undertaken to ensure a coherent strategy was developed for the guideline project. An 'intermediate approach' was adopted, where existing valid guidelines were modified to fit local circumstances. We strove to be transparent at all times about all aspects of the guideline development process. Formative evaluation has shown how the application of evidence-based health care needs adequate resources and requires people with appropriate knowledge and skills. This article charts the progress of the project and highlights how the partnership between the clinical team and the Clinical Librarian has been deemed to be essential to the success of the project. 相似文献
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G. O. S. Ekhaguere 《Higher Education in Europe》2000,25(3):373-379
Although African countries have been continuously expanding their tertiary education systems since independence, these systems remain inadequate for fulfilling the demands being placed on them. Indeed, in many cases, the progress made has been set back by war, disease, and natural catastrophe. Various forms of non-traditional delivery are required, and several examples of distance networking are detailed, including the African Virtual University. A strategic approach to the expansion of access to and opportunities in tertiary education is required making use of assistance from the international partners of African universities. 相似文献
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Donald C. Klein 《Learned Publishing》2000,13(2):83-94
This paper examines how the free distribution of electronic information on the internet is rapidly changing the commercial environment for small to medium‐sized print publishers, and suggests some recommendations for publishers in the process of establishing their own web strategies. It begins by addressing the concept of the ‘network economy’ and the way in which electronic networks have changed the fundamental economics of many businesses. It then suggests seven recommendations for learned and professional society publishers adapting their own business models to the web, highlighting the need to differentiate print from electronic products by building an electronic information services portal for current members and subscribers. 相似文献
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The purpose of the research reported in this chapter is twofold: first, to identify features of classroom environments that promote self-regulated approaches to reading and writing in young children; and second, to work collaboratively with teachers, helping them become proficient at designing tasks and structuring interactions with students that promote self-regulated learning (SRL). Five primary (kindergarten — grade 3) teachers and their students were involved in the study. Evidence from classroom observations indicates that these five teachers consistently involved their students in complex reading and writing activities, choosing what to read and write about, modifying tasks to control challenge, and evaluating their reading and writing processes and products. Also, these teachers provided support that was instrumental to students’ development of SRL, and employed non-threatening evaluation practices. Consistent with previous research that characterizes self-regulated learners, students in these classrooms demonstrated high levels of metacognition, intrinsic motivation, and strategic action. 相似文献
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