Changes in swimming technique during time to exhaustion at freely chosen and controlled stroke rates     

Morgan Alberty  François Potdevin  Jeanne Dekerle  Patrick Pelayo  Philippe Gorce  Michel Sidney 《Journal of sports sciences》2013,31(11):1191-1200

Abstract

The aim of this study was to assess technical changes during constrained swimming in time-to-exhaustion tests. Ten swimmers of national standard performed a maximal 400-m front crawl and two sets of exhaustion tests at 95%, 100%, and 110% of mean 400-m speed. In the first set (free), swimmers had to maintain their speeds until exhaustion and mean stroke rate was recorded for each test. In the second set (controlled), the same speed and individual corresponding stroke rate were imposed. The durations of the exhaustion tests, relative durations of the stroke phases, and arm coordination were analysed. For each speed in the “controlled” set, the exhaustion tests were shorter. Moreover, variables were consistent, suggesting a stabilization of stroke technique. Under the free condition, stroke rate increased to compensate for the decrease in stroke length. At the same time, swimmers reduced the relative duration of their non-propulsive phases in favour of the propulsive phases. Thus, swimmers changed their arm coordination, which came close to an opposition mode. These two constraints enable swimmers both to maintain their stroking characteristics and develop compensatory mechanisms to maintain speed. Moreover, stroke rate can be seen as a useful tool for controlling arm technique during paced exercise.  相似文献   

Effectiveness of a heritage educational program for the acquisition of oral and written French and Tahitian in French Polynesia     

Isabelle Nocus  Philippe Guimard 《Teaching and Teacher Education》2012,28(1):21-31

The research examines the effects of a bilingual pedagogical program (French/Tahitian) on the acquisition of oral and written French as well as the Tahitian language itself in primary schools in French Polynesia. 125 children divided into an experimental group (partially schooled in Tahitian for 300 min per week) and a control group (schooled in French) were followed from the second year of kindergarten to Grade 1 and tested on Tahitian and French language competence. The results show that the program appears to have a positive impact on Tahitian proficiency, without any negative effect on learning of French (oral and reading).  相似文献   

L’apprentissage instrumenté de propriétés en géométrie : propédeutique à l’acquisition d’une compétence de démonstration     

Sylvia Coutat  Colette Laborde  Philippe R. Richard 《Educational Studies in Mathematics》2016,93(2):195-221

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