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111.
112.
Exercise testing on motorised treadmills provides valuable information about running performance and metabolism; however, the impact of treadmill type on these tests has not been investigated. This study compared the energy demand of running on two laboratory treadmills: an HP Cosmos (C) and a Quinton (Q) model, with the latter having a 4.5 times stiffer running platform. Twelve experienced runners ran identical bouts on these treadmills at a range of four submaximal velocities (reported data is for the velocity that approximated 75–81% VO2max). The stiffer treadmill elicited higher oxygen consumption (C: 46.7 ± 3.8; Q: 50.1 ± 4.3 ml·kg?1 · min?1), energy expenditure (C: 16.0 ± 2.5; Q: 17.7 ± 2.9 kcal · min?1), carbohydrate oxidation (C: 9.6 ± 3.1; Q: 13.0 ± 3.9 kcal · min?1), heart rate (C: 155 ± 16; Q: 163 ± 16 beats · min?1) and rating of perceived exertion (C: 13.8 ± 1.2; Q: 14.7 ± 1.2), but lower fat oxidation (C: 6.4 ± 2.3; Q: 4.6 ± 2.5 kcal · min?1) (all analysis of variance treadmill comparisons < 0.01). This study confirms that caution is required when comparing performance and metabolic results between different treadmills and suggests that treadmills will vary in their comparability to over-ground running depending on the running platform stiffness.  相似文献   
113.
The aim of this study was to determine if the hypoxaemic stimulus generated by intense exercise results in the physiological response of increased erythropoietin production. Twenty athletes exercised for 3 min at 109 +/- 2.8% (mean +/- s) maximal oxygen consumption. Estimated oxyhaemoglobin saturation was measured by reflective probe pulse oximetry (Nellcor N200) and was validated against arterial oxyhaemoglobin saturation by CO-oximetry in eight athletes. Serum erythropoietin concentrations-as measured using the INCSTAR Epo-Trac radioimmunoassay-increased significantly by 28 +/- 9% at 24 h post-exercise in 11 participants, who also had an arterial oxyhaemoglobin saturation < or = 91% (P < 0.05). Decreased ferritin levels and increased reticulocyte counts were observed at 96 h post-exercise. However, no significant changes in erythropoietin levels were observed in nine non-desaturating athletes and eight non-exercise controls. Good agreement was shown between arterial oxyhaemoglobin saturation and percent estimated oxyhaemoglobin saturation (limits of agreement = -3.9 to 3.7%). In conclusion, short supramaximal exercise can induce both hypoxaemia and increased erythropoietin levels in well-trained individuals. The decline of arterial hypoxaemia levels below 91% during exercise appears to be necessary for the exercise-induced elevation of serum erythropoietin levels. Furthermore, reflective probe pulse oximetry was found to be a valid predictor of percent arterial oxyhaemoglobin saturation during supramaximal exercise when percent estimated oxyhaemoglobin saturation > or = 86%.  相似文献   
114.
Purpose: Authorities recommend that schools provide a variety of opportunities for students to obtain physical activity (PA) before, during, and after school. This study assessed the prevalence of several school PA practices—including measures of quantity and quality of physical education (PE)—in elementary schools and examined the associations of PA practices with school resources (PE staffing, training, and facilities). Method: Surveys were obtained from respondents in nationally representative samples of elementary schools from 2009–2010 to 2011–2012 (1,831 schools). Results: Few schools (20.8%) provided students with PE class every day, but most (76.3%) had an appropriate PE student-to-teacher ratio ( ≤ 25:1). Many schools (74.0%) offered 20 min of recess daily, but fewer than half offered organized opportunities for PA before or after school (e.g., sports). After controlling for demographics and school size, having a full-time PE teacher and requiring PE teachers to obtain PE-related continuing education (CE) were associated with PE practices such as offering ≥ 150 min of PE per week (for 3rd-grade students) and testing PE knowledge, skills, and fitness. Required CE was also associated with a higher likelihood of offering PA during the school day (i.e., activity breaks and PA outside of PE class) and before or after the school day (i.e., afterschool PA programs). Conclusion: Few schools offer a broad array of PA programming. However, PE staffing and CE are positively associated with many PA practices including those outside of PE, possibly indicating that PE staff serve a crucial role in promoting a whole-school PA-supportive environment.  相似文献   
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This paper strives to provide an insight into the multifaceted relationships that young people have, examining the social, cultural and institutional discourses, which shape their lives. We set out to discuss, from an empirical poststructuralist perspective, the way in which Irish adolescents write about the reality of their lives and privilege certain practices and forms of subjectivity. We are particularly interested in the role and significance of physical activity in the lives of young people, asking what institutional and cultural discourses are brought into play to construct particular identities and social practices associated with leisure and sporting interests. This paper focuses on a purposeful sample of 168 written narratives of Irish post-primary students (14–17 years of age), chosen to represent the gender of students, a range of rural and urban school locales from different geographic locations and single sex and co-educational schools. We focus on the inter-relationships between (1) family and friends; (2) community-localism and tradition; (3) commodification and globalisation; (4) popular culture; and (5) gendered patterns of leisure and sporting interests. The family is a strong focal point for these young people as are their friends and being part of a community. The young people (boys in particular) are significant consumers of ‘media sport’ and both girls and boys were knowledgeable of national and international politics. We also comment on the extent to which female and male adolescents negotiate, similarly or differently, culturally dominant discourses within physical activity and sport, with significantly more boys choosing to write about physical activity and sport in their narratives.  相似文献   
117.
Gymnastics vaulting relies on a specialized take‐off board for propulsion during the take‐off phase of the vault. There is little information on the vault board and its behaviour. The aim of this study was to characterize the behaviour of the vault board during handspring drill take‐offs of young male gymnasts (n = 36). The side of the top surface of the vault board and the wooden base were marked with three reflective markers, placed at the end of the vault board nearest the vault table and the centres of the two rearmost coil springs. The vault board surface was divided into two areas, rear and middle, based on marker location. The gymnasts’ groups were determined from the location of the gymnast's lateral malleolus at vault board contact. Landings with the malleolus directly above or behind the rearmost marker were considered rear landings; landings with the malleolus forward of the rearmost marker were considered middle landings. Marker movements were automatically digitized and the right malleolus was hand digitized at 120 Hz. The maximum vertical displacement, vertical deflection time, and vertical velocity at take‐off of the vault board markers did not differ statistically between board contact groups (all p > 0.05). The lateral malleolus velocity components also did not differ between board contact groups. Some low to moderately strong correlations were observed between the various marker displacements, durations and take‐off velocities. Modest correlations were obtained between board markers and right malleolus velocities. The results indicate that foot contact on the vault board, as defined here, did not result in differences in board marker behaviour or right lateral malleolus velocities. This information does not support the idea that vault board contacts at the rear of the vault board are worse than contacts near the middle of the vault board. More research is needed to ascertain the role of the vault board's vibration characteristics to whole body actions that are observed in the subsequent preflight phase.  相似文献   
118.
This paper explores the changing terrain of disability support policy in Australia. Drawing on a critical disability framework of policy sociology, the paper considers the policy problem of access to education for people with disabilities under recent reform by means of the National Disability Insurance Scheme (NDIS), which commenced full roll-out across the country from July 2016. The paper reviews NDIS reports, legislation and associated literature to consider how eligibility to scheme participation and education services are shaped, and how education is positioned in the development and implementation of the NDIS. The analysis highlights tensions that exist for people with disabilities and their families who both access the scheme and who might draw on its provision to support their education, because of the way the policy is oriented towards pathological categorisation, standardised outcomes and service delineation rather than integrated support and informed involvement. The paper concludes by arguing that despite the policy priority across Organisation for Economic Co-operation and Development countries of increasing lifelong learning opportunities, fragmented NDIS policy in Australia prevents people with disabilities from achieving this ideal.  相似文献   
119.
This paper sets out to outline current discussions in Ireland around teachers being responsible for assessing their own students’ work, and the subsequent impact such a perspective is having (or not) on the delivery and assessment of physical education in Ireland. Our intention is to contribute to assessment considerations, while acknowledging the nuances of the Irish education context, and the positioning of physical education within such nuances. This discussion is particularly timely given the very recent endorsement for the introduction of the new Leaving Certificate Physical Education as a full optional subject. We begin by discussing more specifically assessment in Irish primary and post-primary schools, drawing attention to the limited Irish assessment-related research being conducted in both contexts. We then explore assessment developments related to Irish primary physical education and post-primary physical education and compare the extent to which such developments are limited in comparison to international assessment interests and practices in physical education. We conclude with suggestions related to studying (pre-service) teachers’ and students’ exposure to assessment in order to understand how we could alter the balance of assessment purposes and uses in Irish schools.  相似文献   
120.
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