Physiological and metabolic responses of wheelchair athletes in different racing classes to prolonged exercise     

Campbell IG  Williams C  Lakomy HK 《Journal of sports sciences》2004,22(5):449-456

The aims of this study were to examine and compare selected physiological and metabolic responses of wheelchair athletes in two paraplegic racing classes [T3: n = 8 (lesion levels T1-T7; paraplegics); T4: n = 9 (lesion levels below T7; paraplegics)] to prolonged exercise. In addition, we describe the responses of three tetraplegic athletes [T2: n = 3 (lesion levels C6/C7: tetraplegics)]. Twenty athletes completed 90 min of exercise at 75% VO2peak on a motorized treadmill adapted for wheelchairs. The mean (+/- s) heart rates of the T3 and T4 racing classes were 165 +/- 2 and 172 +/- 6 beats.min-1, respectively. For the T4 racing class, heart rate gradually increased during the test (P < 0.05), whereas for the T3 racing class, heart rate reached a plateau after an initial increase. The mean heart rate of the tetraplegics was 114 +/- 3 beats.min-1. The T3 and T4 classes exhibited similar respiratory exchange ratios, plasma lactate and glucose concentrations throughout the test. For both the T3 and T4 racing class, free fatty acid, glycerol, ammonia, urea and potassium concentrations had increased from resting values by the end of the test (P < 0.05). In conclusion, the results of this study suggest that endurance-trained wheelchair athletes are able to maintain velocities equivalent to the same relative exercise intensity (75% VO2peak) for prolonged periods irrespective of lesion level.  相似文献   

Which starting style is faster in sprint running--standing or crouch start?     

Salo A  Bezodis I 《Sports biomechanics / International Society of Biomechanics in Sports》2004,3(1):43-53

The purpose of this study was to further understand the biomechanical differences between the standing and crouch starting methods, and to investigate whether one of the starting styles provides better acceleration and proves to be faster. Six university track team sprinters performed 2 x 3 x 50 m trials. Digitised video, photocell timing, and velocity data revealed that during the first steps of the performance the standing start produced higher body centre of mass horizontal velocity than the crouch start. This may be due to the longer distance between the feet in the standing start, which caused longer push-off phases, and the work against gravity in the crouch start. However, this advantage in horizontal velocity disappeared by the 10 m mark, where similar velocities were recorded with both start styles. Further, there was no statistically significant difference between the two starting styles in horizontal velocity at the 25 m mark, nor in the time to reach the 25 m or 50 m mark. Regarding relay running, where athletes need to decide to adopt either a crouch start without starting blocks or a standing start, there seems to be no specific reason for outgoing athletes to use a crouch start, although this area warrants further investigation.  相似文献   

Editorial     

Ian D. Selwood 《Education and Information Technologies》2007,12(4):189-190

  相似文献   

Introduction     

Ian Winchester 《Interchange》1985,16(1):1-3

  相似文献   

Development and validation of the moral disengagement in sport scale     

Boardley ID  Kavussanu M 《运动与训练心理学杂志》2007,29(5):608-628

A sport-specific measure of moral disengagement was developed in 2 studies. In Study 1, a 59-item questionnaire was developed and tested with 308 athletes from 5 team sports. A series of confirmatory factor analyses (CFA) testing different models suggested the model that best fitted the data had 6 first-order factors that could be represented by 1 second-order factor. Study 2 involved 305 athletes from the same 5 sports. CFA confirmed the 6-factor, second-order structure for the final 32-item measure. Results from Study 2 supported the construct validity of the scale, providing evidence for the factorial, concurrent, convergent, and discriminant validity. The Moral Disengagement in Sport Scale (MDSS) is proposed as a valid and reliable measure of moral disengagement for use in the sport context.  相似文献   

Scratching the Surface of the History of Military Medicine     

Ian Wilson 《Metascience》2009,18(2):285-287

  相似文献   

Book reviews     

E. D. Duryea  Neville Bennett  Sharom Ahmat  Dietrich Brandt  Lionel S. Lewis  Ian Woodburn  Claude E. Welch Jr.  Sheila Slaughter  Pierre L. van den Berghe  Doreen Harrison 《Higher Education》1980,9(2):227-237

  相似文献   

Book review     

Jon Lauglo  C. H. Dobinson  Wolfgang Mitter  Ian Lister  G. W. Parkyn  T. Neville Postlethwaite  R. Gardner  Walter Hahn  John Lowe  A. J. Cropley  Georges Belbenoit  Janusz J. Tomiak  Bill Halls 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1976,22(1):107-126

  相似文献   

Geometry of screw compressor rotors and their tools     

Nikola STOSIC  Ian K. SMITH  Ahmed KOVACEVIC  Elvedin MUJIC 《浙江大学学报(A卷英文版)》2011,12(4):310-326

This paper presents a method of general geometrical definitions of screw machine rotors and their manufacturing tools. It describes the details of lobe shape specification, and focuses on a new lobe profile, which yields a larger cross-sectional area and shorter sealing lines resulting in higher delivery rates for the same tip speed. A well proven mathematical model was used to determine the optimum profile, compressor housing size, and compressor ports to achieve the superior compressors.  相似文献   

Funding,reputation and targets: the discursive logics of high-stakes testing     

Steven Lewis  Ian Hardy 《Cambridge Journal of Education》2015,45(2):245-264

This paper provides insights into teacher and school-based administrators’ responses to policy demands for improved outcomes on high-stakes, standardised literacy and numeracy tests in Australia. Specifically, the research reveals the effects of the National Assessment Program – Literacy and Numeracy (NAPLAN), and associated policies, in the state of Queensland. Drawing suggestively across Michel Foucault’s notions of disciplinary power and subjectivity, and Pierre Bourdieu’s concept of social fields, the research utilises interviews with teachers and school-based administrators to reveal how high-stakes, standardised testing practices served to discursively constitute performative teacher subjectivities around issues of funding, teacher and school reputation and target-setting within what is described as the ‘field of schooling practices’. The paper argues that the contestation evident within this field is also reflective and constitutive of more educative schooling discourses and practices, even as performative logics dominate.  相似文献