Augmenting performance feedback does not affect 4 km cycling time-trials in the heat     

Mark Waldron  Vincent Villerius  Aron Murphy 《Journal of sports sciences》2015,33(8):786-794

We compared the effects of (1) accurate and (2) surreptitiously augmented performance feedback on power output and physiological responses to a 4000 m time-trial in the heat. Nine cyclists completed a baseline (BaseL) 4000 m time-trial in ambient temperatures of 30°C, followed by two further 4000 m time-trials at the same temperature, randomly assigning the participants to an accurate (ACC; accurate feedback of baseline) or deceived (DEC; 2% increase above baseline) feedback group. The total power output (PO) and aerobic (P_aer) and anaerobic (P_an) contributions were determined at 0.4 km stages during the time-trials, alongside measurements of rectal (T_rec) and skin (T_skin) temperatures. There were no differences (P > 0.05) in any of the variables between BaseL, ACC and DEC, despite increases (P < 0.05) in T_rec and T_skin. Typical pacing profiles were demonstrated; however, there was no interaction (P > 0.05) between feedback condition and time-trial stage. Providing surreptitiously augmented performance feedback to well-trained cyclists did not alter their performance or physiological responses to a 4000 m time-trial in a hot environment. The assumed influence of augmented performance feedback was nullified in the heat, perhaps reflecting a central down-regulation of exercise intensity in response to an increased body temperature.  相似文献   

Reliability and validity of a talent identification test battery for seated and standing Paralympic throws     

Jemima Grace Spathis  Mark James Connick  Emma Maree Beckman  Peter Anthony Newcombe  Sean Michael Tweedy 《Journal of sports sciences》2015,33(8):863-871

Paralympic throwing events for athletes with physical impairments comprise seated and standing javelin, shot put, discus and seated club throwing. Identification of talented throwers would enable prediction of future success and promote participation; however, a valid and reliable talent identification battery for Paralympic throwing has not been reported. This study evaluates the reliability and validity of a talent identification battery for Paralympic throws. Participants were non-disabled so that impairment would not confound analyses, and results would provide an indication of normative performance. Twenty-eight non-disabled participants (13 M; 15 F) aged 23.6 years (±5.44) performed five kinematically distinct criterion throws (three seated, two standing) and nine talent identification tests (three anthropometric, six motor); 23 were tested a second time to evaluate test–retest reliability. Talent identification test–retest reliability was evaluated using Intra-class Correlation Coefficient (ICC) and Bland–Altman plots (Limits of Agreement). Spearman’s correlation assessed strength of association between criterion throws and talent identification tests. Reliability was generally acceptable (mean ICC = 0.89), but two seated talent identification tests require more extensive familiarisation. Correlation strength (mean r_s = 0.76) indicated that the talent identification tests can be used to validly identify individuals with competitively advantageous attributes for each of the five kinematically distinct throwing activities. Results facilitate further research in this understudied area.  相似文献   

Reclaiming Canada Through Its ‘Ancient’ Sport: Lacrosse and the Native Sons of Canada in Late 1920s Alberta     

Robert Kossuth  David McMurray 《国际体育史杂志》2015,32(14):1642-1660

Lacrosse has long been considered Canada's national sport and, beginning in the latter half of the nineteenth century, became tied to the nationalist ambitions that sought to promote a national identity through the ‘creation’ of a uniquely Canadian game. Popular in the decades prior to the turn of the twentieth century, lacrosse in Alberta began to decline after the First World War, becoming a marginal sport played only in the province's larger cities. A brief and unexpected revival of lacrosse occurred in two communities, Edmonton and Lethbridge, in the 1920s championed by a nativist organization, the Native Sons of Canada (NSC). For this group lacrosse represented a natural means to promote their ‘Canada First’ ideology to young male Albertans. In Edmonton, the Native Sons sponsored a senior men's lacrosse team that garnered some local and regional attention, while attempts by the Lethbridge assembly to promote youth lacrosse in 1927 were largely unsuccessful. Despite the continuing affinity between Canadian nationalism and lacrosse, the NSC were ineffective in their efforts to revive interest in the sport. The ‘national’ game did not provide nativists in Alberta the platform they sought to promote their nationalist agenda.  相似文献   

Effects of changing speed on knee and ankle joint load during walking and running     

Ana Cristina de David  Felipe Pivetta Carpes  Darren Stefanyshyn 《Journal of sports sciences》2015,33(4):391-397

Joint moments can be used as an indicator of joint loading and have potential application for sports performance and injury prevention. The effects of changing walking and running speeds on joint moments for the different planes of motion still are debatable. Here, we compared knee and ankle moments during walking and running at different speeds. Data were collected from 11 recreational male runners to determine knee and ankle joint moments during different conditions. Conditions include walking at a comfortable speed (self-selected pacing), fast walking (fastest speed possible), slow running (speed corresponding to 30% slower than running) and running (at 4 m · s^?1 ± 10%). A different joint moment pattern was observed between walking and running. We observed a general increase in joint load for sagittal and frontal planes as speed increased, while the effects of speed were not clear in the transverse plane moments. Although differences tend to be more pronounced when gait changed from walking to running, the peak moments, in general, increased when speed increased from comfortable walking to fast walking and from slow running to running mainly in the sagittal and frontal planes. Knee flexion moment was higher in walking than in running due to larger knee extension. Results suggest caution when recommending walking over running in an attempt to reduce knee joint loading. The different effects of speed increments during walking and running should be considered with regard to the prevention of injuries and for rehabilitation purposes.  相似文献   

Informing in-season tactical periodisation in team sport: development of a match difficulty index for Super Rugby     

Samuel J. Robertson  David G. Joyce 《Journal of sports sciences》2015,33(1):99-107

In team sports, tactical periodisation refers to the planned manipulation of training loads with the aim of prioritising athlete readiness for matches of greatest importance. Although monitoring of athletes’ physical condition is often used to inform this planning, the direct influence of external factors on match difficulty has not been well quantified. In this study, a ‘match difficulty index’ (MDI) for use in Super Rugby was developed, based on the influence imparted by five external factors on previous match outcomes. Specifically, information relating to match location, days break between matches, time-zone change and opposition ladder position (both current and previous year) were collected for matches played during the 2011–2013 Super Rugby seasons. Logistic regression analyses were used to assess the importance of each of these factors with respect to match outcome (win/loss), with opposition ladder position and match location (home, domestic away or international) exerting the greatest influence on match difficulty. Three separate cross-validated models were constructed, with match outcome classification performance reported as 66.2%, 65.5% and 63.7% respectively. The three MDI models emanating from this study can each be used to inform tactical periodisation program design both prior to and during the regular season.  相似文献   

The impact of data reduction on the intra-trial reliability of a typical measure of lower limb musculoskeletal stiffness     

Mark P. Moresi  Elizabeth J. Bradshaw  David A. Greene  Geraldine A. Naughton 《Journal of sports sciences》2015,33(2):180-191

Double-leg repeated jumping tasks are commonly used as measures of lower limb stiffness in exercise science research. Within similar stiffness calculations, variation in data-reduction criteria exists. The impact of these varied data-reduction methods on stiffness measures is unknown. Sixteen adolescent female participants from varied physical activity backgrounds performed 15 self-paced, bent-knee continuous jumps (CJb) on two force plates. Leg stiffness was calculated as the ratio of the peak force and the centre of mass displacement for each contact. Using combinations of criteria based on previous literature, 83 data-reduction methods were applied to the raw data. Data reduction suitability was assessed based on intra-trial reliability, the number of participants excluded and the average contacts excluded. Four data-reduction methods were deemed suitable for use with adolescent female populations, with three consecutive contacts within 1 SD of the average jump frequency considered optimal. The average individual stiffness values were not greatly influenced by the data-reduction method; however, for a single participant, a stiffness change of up to 6 kN · m^?1 (30%) was observed. The role and potential impact of data-reduction methods used to evaluate measures of lower limb stiffness during repeated jumping tasks warrants consideration.  相似文献   

Teaching Chinese Literacy in the Early Years: Psychology,Pedagogy and Practice     

Linda Tsung 《Frontiers of Education in China》2015,10(4):659-660

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Ten Years’ Chinese-Canadian Collaboration in Undergraduate Education in Fujian Agriculture and Forestry University of China: Curriculum Development     

Songliang Wang  Claude Caldwell  Liqing Wei  Haiyan Su 《Frontiers of Education in China》2015,10(3):427-438

The Fujian Agriculture and Forestry University-Nova Scotia Agricultural College (FAFU-NSAC) 2 + 2 undergraduate program initiated in 2003 is a model for creative collaboration between China and Canada in undergraduate education. This paper addresses the achievements of the program development and highlights the process for successful curriculum development in the joint program. The authors also discuss some issues and challenges related to the Chinese-Canadian experience in undergraduate education, and propose some recommendations for further collaborations including: enlarging the scale of qualified programs; proposing a systematic baseline to control the program at a macro-level; simplifying coordination procedures with foreign partners; and adjusting the emphasis of courses introduced by the cooperative partner from quantity to quality.  相似文献   

A Multilevel Analysis of Asian Immigrant Children’s Reading Achievement in the Early Years: Evidence from the ECLS-K Data     

Guofang Li  Lihong Yang 《Frontiers of Education in China》2015,10(1):110-131

This study investigates 1.5 generation¹ Asian immigrant children’s (n = 264) early literacy achievement patterns, treating them as a heterogeneous group. Specifically, the within-group variances in reading achievement from kindergarten to third grade are examined, drawing on four waves of data from the ECLS-K class of 1998–1999. Our analysis shows that ethnicity plays a role in shaping the children’s initial reading readiness and later growth, but the effects of languages spoken at home are not significant. Our analysis also demonstrates a persistent achievement gap between low- and high-socioeconomic status (SES) Asian groups. However, gender difference in terms of children’s reading development is not found to be significant. There is also no interaction between SES and the other factors such as gender, ethnicity and language backgrounds.  相似文献   

The formulation and transition of China’s educational policy from 1978 to 2007: A policy discourse analysis     

Ruth Hayhoe 《Frontiers of Education in China》2015,10(1):164-166

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