Maximal oxygen uptake versus maximal power output in children     

Dencker M  Thorsson O  Karlsson MK  Lindén C  Wollmer P  Andersen LB 《Journal of sports sciences》2008,26(13):1397-1402

Maximal oxygen uptake VO(2max)) is considered the optimal method to assess aerobic fitness. The measurement of VO(2max), however, requires special equipment and training. Maximal exercise testing with determination of maximal power output offers a more simple approach. This study explores the relationship between [Vdot]O(2max) and maximal power output in 247 children (139 boys and 108 girls) aged 7.9-11.1 years. Maximal oxygen uptake was measured by indirect calorimetry during a maximal ergometer exercise test with an initial workload of 30 W and 15 W x min(-1) increments. Maximal power output was also measured. A sample (n = 124) was used to calculate reference equations, which were then validated using another sample (n = 123). The linear reference equation for both sexes combined was: VO(2max) (ml x min(-1)) = 96 + 10.6 x maximal power + 3.5 . body mass. Using this reference equation, estimated VO(2max) per unit of body mass (ml x min(-1) x kg(-1)) calculated from maximal power correlated closely with the direct measurement of VO(2max) (r = 0.91, P <0.001). Bland-Altman analysis gave a mean limits of agreement of 0.2+/-2.9 (ml x min(-1) x kg(-1)) (1 s). Our results suggest that maximal power output serves as a good surrogate measurement for VO(2max) in population studies of children aged 8-11 years.  相似文献   

Intensity and physiological strain of competitive ultra-endurance exercise in humans     

Lucas SJ  Anglem N  Roberts WS  Anson JG  Palmer CD  Walker RJ  Cook CJ  Cotter JD 《Journal of sports sciences》2008,26(5):477-489

The aim of this study was to determine the magnitude and pattern of intensity, and physiological strain, of competitive exercise performed across several days, as in adventure racing. Data were obtained from three teams of four athletes (7 males, 5 females; mean age 36 years, s = 11; cycling .VO(2 peak) 53.9 ml . kg(-1) . min(-1), s = 6.3) in an international race (2003 Southern Traverse; 96 - 116 h). Heart rates (HR) averaged 64% (95% confidence interval: +/- 4%) of heart rate range [%HRR = (HR - HR(min))/(HR(max) - HR(min)) x 100] during the first 12 h of racing, fell to 41% (+/-4%) by 24 h, and remained so thereafter. The level and pattern of heart rate were similar across teams, despite one leading and one trailing all other teams. Core temperature remained between 36.0 and 39.2 degrees C despite widely varying thermal stress. Venous samples, obtained before, during, and after the race, revealed increased neutrophil, monocyte and lymphocyte concentrations (P < 0.01), and increased plasma volume (25 +/- 10%; P < 0.01) with a stable sodium concentration. Standardized exercise tests, performed pre and post race, showed little change in the heart rate-work rate relationship (P = 0.53), but a higher perception of effort post race (P < 0.01). These results provide the first comprehensive report of physiological strain associated with adventure racing.  相似文献   

Entwicklungsförderung im außerschulischen Kinder- und Jugendsport     

Ralf Sygusch  Christian Herrmann 《Sportwissenschaft》2009,39(3):210-222

Extracurricular sport is coupled with many socialization and education potentials for developmental promotion of children and adolescents. The promotion concept “Psychosocial resources in sports” (Sygusch 2007) provides the starting point for the development of capabilities to react and perform in sports as well as for general personality development through sport. This incentive concept is oriented towards training and competitive routine as well as on concrete demands from types of sport. Among others it justifies the methodical measures for promotion of selected resources (e. g. self-concept, cooperative ability). Within the framework of the accompanying study PRimus (psychosocial resources in youth sports) an evaluation of the execution of the programme was realized. Among others it was investigated whether the incentive concept can be implemented in organized child and youth sports. The results indicate that the incentive concept “pedagogically arranged extracurricular youth sports” is implemented by voluntary youth trainers in most instances and is estimated by trainers to be feasible.  相似文献   

What static and dynamic properties should slalom skis possess? Judgements by advanced and expert skiers     

Fischer C  Overney LS  Fauve M  Blanke O  Rhyner H  Herzog MH  Bourban PE  Månson JA 《Journal of sports sciences》2007,25(14):1567-1576

Flexural and torsional rigidity are important properties of skis. However, the flexural and torsional rigidity that lead to optimal performance remain to be established. In the present study, four pairs of slalom skis that differed in flexural and torsional rigidity were tested by advanced and expert skiers. Using a 10-item questionnaire, different aspects of the skis' performance were rated on a 9-point scale. For each pair of skis, physical measurements were compared with the ratings of the two groups of skiers. Correlations (Spearman) were then determined between (i) different mechanical properties of the skis (static and dynamic), (ii) subjective assessments of the participants, and (iii) properties of the skis and the participants' assessments. The latter showed that expert skiers rate the aspects of the skis more accurately than advanced skiers. Most importantly, expert skiers are particularly sensitive to torsion of the skis. These results suggest that such highly rated elements should be addressed in future ski designs.  相似文献   

The Early History of David Bohm’s Quantum Mechanics Through the Perspective of Ludwik Fleck’s Thought-Collectives     

Christian Forstner 《Minerva》2008,46(2):215-229

This paper analyses the early history of David Bohm’s mechanics from the perspective of Ludwik Fleck’s thought-collectives and shows how the thought-style of the scientific community limits the possible modes of thinking and what new possibilities for the construction of a new theory arise if these limits are removed.  相似文献   

A System Approach to a Postgraduate Course Based on Behavioural Objectives     

Christian Olsen 《British journal of educational technology : journal of the Council for Educational Technology》1973,4(3):204-215

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Animations-Framework in Java
Systematische Animationsentwicklung mit Mehrschichtenarchitektur     

Christian Weidauer 《Informatik - Forschung und Entwicklung》2000,41(1):83-91

Multimedia-Anwendungen und Animationen sind durch Dynamik gekennzeichnet. Die Dynamik muss sich in der Architektur der Anwendung niederschlagen. Eine M?glichkeit hierbei besteht darin, die Dynamik in einer speziellen Softwareschicht innerhalb einer Mehrschichtenarchitektur zu realisieren. Dieses Papier stellt ein Animations-Framework in Java vor, das diese Architektur JavaBeans-konform als muster-orientiertes Framework realisiert und somit die systematische Entwicklung von animierten Multimedia-Anwendungen in Java unterstützt.  相似文献   

Spieker,Susanne, Die Entstehung des modernen Erziehungsdenkens aus der europäischen Expansion (Interkulturelle Pädagogik und postkoloniale Theorie,vol. 4), edited by Heike Niedrig and Louis Henri Seukwa,Frankfurt am Main,Peter Lang, 2015, 343 pp., €61.60, ISBN 978-3-631-65089-9     

Christian Roith 《Paedagogica Historica: International Journal of the History of Education》2018,54(3):371-374

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Families support their children's success in science learning by influencing interest and self‐efficacy     

Li Sha  Christian Schunn  Meghan Bathgate  Adar Ben‐Eliyahu 《科学教学研究杂志》2016,53(3):450-472

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Naphtali Herz Wessely,Worte des Friedens und der Wahrheit. Dokumente einer Kontroverse über Erziehung in der europäischen Spätaufklärung,edited, introduced and commented on by Ingrid Lohmann,co-edited by Rainer Wenzel and Uta Lohmann.     

Christian Roith 《Paedagogica Historica: International Journal of the History of Education》2015,51(6):783-787

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