Performance differences when using 26- and 29-inch-wheel bikes in Swiss National Team cross-country mountain bikers     

Thomas Steiner  Beat Müller  Thomas Maier  Jon Peter Wehrlin 《Journal of sports sciences》2016,34(15):1438-1444

The purpose of this study was to analyse the effect of bike type – the 26-inch-wheel bike (26“ bike) and the 29-inch-wheel bike (29“ bike) – on performance in elite mountain bikers. Ten Swiss National Team athletes (seven males, three females) completed six trials with individual start on a simulated cross-country course with 35 min of active recovery between trials (three trials on a 26“ bike and three trials on a 29“ bike, alternate order, randomised start-bike). The course consisted of two separate sections expected to favour either the 29“ bike (section A) or the 26“ bike (section B). For each trial performance, power output, cadence and heart rate were recorded and athletes’ experiences were documented. Mean overall performance (time: 304 ± 27 s vs. 311 ± 29 s; P < 0.01) and performance in sections A (P < 0.001) and B (P < 0.05) were better when using the 29“ bike. No significant differences were observed for power output, cadence or heart rate. Athletes rated the 29“ bike as better for performance in general, passing obstacles and traction. The 29“ bike supports superior performance for elite mountain bikers, even on sections supposed to favour the 26“ bike.  相似文献   

A topography of free kicks in soccer     

Daniel Link  Otto Kolbinger  Hendrik Weber  Michael Stöckl 《Journal of sports sciences》2016,34(24):2312-2320

ABSTRACT

This study investigates the spatial relationship of performance variables for soccer free kicks. In order to suggest ways in which players might optimise their performance, we collected data from free kicks (<35 m to goal line) of two German Bundesliga seasons (2013/14, 2014/15) (n = 1624). In the analysis, we applied the ISO-map approach using colour gradients to visualise the mean values of a variable on a 2D-map of the pitch. Additionally, variograms were used to describe the degree of spatial dependence of the free kick variables. Results show that DENSITY, TYPE OF PLAY, PLAYERS IN WALL, DISTANCE TO WALL and RULE VIOLATION were strongly spatially dependent. Centrality and proximity to the goal increased the variables PLAYERS IN WALL, RULE VIOLATIONS and INTERRUPTION TIME, and the ratio of goals scored increased from 5.9% (central far) to 10.9% (central near). In 70.9% of the shots, players preferred a switched laterality, which did not result in a higher success rate. Furthermore, there was no statistical advantage for the defensive team when DISTANCE TO WALL was below 9.15 m or when there was a RULE VIOLATION. Crosses had a success rate (i.e., first controlled ball contact after the cross) of 20.8%. Played with natural laterality, they were 5% more successful than with switched laterality. Crosses from the right side outside the penalty box were 10% more successful than from the left side. Therefore, it might be worthwhile practising the defence of balls coming from this side.  相似文献   

Intrinsic Versus Extrinsic Motivation: An Approach/Avoidance Reformulation     

Martin V. Covington  Kimberly J. Müeller 《Educational Psychology Review》2001,13(2):157-176

The main purpose of this article is to advance an alternative perspective on the relationship between intrinsic and extrinsic motivation, and in particular to examine critically the assertion that these processes are antagonistic such that the will to learn for its own sake is inhibited by the presence of extrinsic, tangible rewards and incentives such as school grades. The presumption of an antagonistic relationship largely depends on the theoretical perspective adopted. An alternative interpretation based on need achievement theory leads to distinctly different conclusions. Exploring this new perspective allows one to identify both the conditions under which intrinsic motives may coexist with extrinsic motives as well as to consider some of the means by which intrinsic motives and caring about learning can be stimulated in their own right in school settings.  相似文献   

Momentum sequence and environmental climate influence levels of perceived psychological momentum within a sport competition     

Walid Briki  Keith D. Markman  Guillaume Coudevylle  Stéphane Sinnapah  Olivier Hue 《European Journal of Sport Science》2016,16(3):350-357

The present study examined the influence of momentum sequence (positive vs. negative) and environmental climate (hot–wet vs. neutral) on supporters’ (i.e. virtual observers’) reported levels of perceived psychological momentum (PM) during a simulated cycling competition. Participants supported one of two competing cyclists involved in a race that was displayed on a screen in a lecture hall. The race scenario was manipulated so that the supported cyclist appeared to undergo either a positive or negative momentum sequence. In addition, participants were either exposed to a hot–wet environmental climate or to a neutral environmental climate while observing the race scenario. According to the results, reported levels of PM were higher in the positive momentum sequence condition than in the negative momentum sequence condition, consistent with the notion that supporters’ PM is influenced by a positivity bias, and reported levels of PM were also found to be higher in the hot–wet climate condition than in the neutral climate condition, consistent with the notion that environmental climate is a contextual factor that influences PM through the operation of a causal augmenting mechanism.  相似文献   

Bilateral practice improves dominant leg performance in long jump     

Anne Focke  Sina Spancken  Christian Stockinger  Benjamin Thürer  Thorsten Stein 《European Journal of Sport Science》2016,16(7):787-793

Benefits of bilateral practice both for the non-dominant and for the dominant body side have been shown in several studies. Thereby, most of the studies included movement tasks of the upper extremity or investigated sports games in which the ability of acting bilaterally is an essential basis for success and, thus, a bilateral practice is reasonable anyway. Individual unilaterally performed sports including movement tasks of the lower extremity are rarely investigated. Therefore, the aim of our study was to test if contralateral transfer due to bilateral practice can be found in an unilaterally performed sport including the lower extremity. We trained and tested 61 adolescent athletes in long jump to compare the jumping performance of the dominant leg after a 12-week practice period between two groups: a bilateral practice group that practiced specific long jump exercises with both the dominant and non-dominant leg and an unilateral practice group that practiced specific long jump exercises only with the dominant leg. Results showed a superior effect of bilateral practice compared to unilateral practice regarding the jumping performance of the dominant leg. The performance increase at post-test and retention-test for the dominant limb was significantly higher for the bilateral practice group (pre-to-post: 5.2%, pre-to-retention: 7.4%) compared to the unilateral practice group (pre-to-post: 3.4%, pre-to-retention: 4.5%). Thus, bilateral practice should be established in the early practice programmes of track and field athletes to improve the performance of the dominant take-off leg.  相似文献   

A Response to Karmiloff and Karmiloff-Smith (1998) 'Everything your baby would ask If only she or he could talk '     

Conrad Martin 《Educational Psychology in Practice》2001,17(3):287-291

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Wandel in der Fremdsprachenpolitik der DDR     

Günter Böhme 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1991,37(1):168-172

Ohne Zusammenfassung  相似文献   

Black Women,Identity and Schooling: Reclaiming Our Work in Shifting Contexts     

Sheryl?Conrad?CozartEmail author  Paula?Groves?Price 《The Urban Review》2005,37(3):173-179

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Admission test for medical studies in West Germany     

Günter Trost 《Studies in Educational Evaluation》1984,10(1):87

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Search for Symbol Sense Behavior: Students in Upper Secondary Education Solving Algebraic Physics Problems     

Turşucu  Süleyman  Spandaw  Jeroen  de Vries  Marc J. 《Research in Science Education》2020,50(5):2131-2157

Research in Science Education - Students in upper secondary education encounter difficulties in applying mathematics in physics. To improve our understanding of these difficulties, we examined...  相似文献