Time motion analysis of 2001 and 2002 super 12 rugby     

Grant Duthie  David Pyne  Sue Hooper 《Journal of sports sciences》2013,31(5):523-530

The aim of this study was to quantify movements of Super 12 rugby players in competition because information on elite rugby players' movements is unavailable. Players were categorized into forwards [front (n = 16) and back row (n = 15)] and backs [inside (n = 9) and outside backs (n = 7)] and their movements analysed by video-based time motion analysis. Movements were classified as rest (standing, walking and jogging) and work (striding, sprinting, static exertion, jumping, lifting or tackling). The total time, number and duration of individual activities were assessed, with differences between groups evaluated using independent sample t-tests (unequal variances), while differences between halves were assessed with paired sample t-tests. Forwards had 7:47?min:s (95% confidence limits: 6:39 to 8:55?min:s, P<0.01) more time in static exertion than backs, but backs spent 0:52 (0:34 to 1:09, P = 0.01) min:s more time sprinting than forwards, and had a 0.7 (0.3 to 1.2, P = 0.01) s longer duration of each sprint. Forwards spent 7:31 (5:55 to 9:08) min:s more time in work activities (P = 0.01) and had 2.1 (1.3 to 2.8) s longer work durations (P<0.01) than backs. The results indicate frequent short duration (<4?s) work efforts followed by moderate duration (<20?s) rest for forwards, and extended (>100?s) rest duration for backs. High-intensity efforts involved static exertion for forwards (mean?±?standard deviation frequency = 80?±?17) and sprinting for backs (27?±?9). In conclusion, after nearly a decade since becoming professional, elite rugby union is still characterized by highly intense, intermittent movement patterns and marked differences in the competition demands of forwards and backs.  相似文献   

Factors influencing physiological responses to small-sided soccer games     

Ermanno Rampinini  Franco M. Impellizzeri  Carlo Castagna  Grant Abt  Karim Chamari  Aldo Sassi 《Journal of sports sciences》2013,31(6):659-666

Abstract

The aim of this study was to examine the effects of exercise type, field dimensions, and coach encouragement on the intensity and reproducibility of small-sided games. Data were collected on 20 amateur soccer players (body mass 73.1 ± 8.6 kg, stature 1.79 ± 0.05 m, age 24.5 ± 4.1 years, [Vdot]O_2max 56.3 ± 4.8 ml · kg^?1 · min^?1). Aerobic interval training was performed during three-, four-, five- and six-a-side games on three differently sized pitches, with and without coach encouragement. Heart rate, rating of perceived exertion (RPE) on the CR10-scale, and blood lactate concentration were measured. Main effects were found for exercise type, field dimensions, and coach encouragement (P < 0.05), but there were no interactions between any of the variables (P > 0.15). During a six-a-side game on a small pitch without coach encouragement, exercise intensity was 84 ± 5% of maximal heart rate, blood lactate concentration was 3.4 ± 1.0 mmol · l^?1, and the RPE was 4.8. During a three-a-side game on a larger pitch with coach encouragement, exercise intensity was 91 ± 2% of maximal heart rate, blood lactate concentration was 6.5 ± 1.5 mmol · l^?1, and the RPE was 7.2. Typical error expressed as a coefficient of variation ranged from 2.0 to 5.4% for percent maximal heart rate, from 10.4 to 43.7% for blood lactate concentration, and from 5.5 to 31.9% for RPE. The results demonstrate that exercise intensity during small-sided soccer games can be manipulated by varying the exercise type, the field dimensions, and whether there is any coach encouragement. By using different combinations of these factors, coaches can modulate exercise intensity within the high-intensity zone and control the aerobic training stimulus.  相似文献   

Metrics of meaningfulness as opposed to sleights of significance     

Edward M. Winter  Grant A. Abt  Alan M. Nevill 《Journal of sports sciences》2013,31(10):901-902

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Three-dimensional anthropometric analysis: Differences between elite Australian rowers and the general population     

Natasha Schranz  Grant Tomkinson  Tim Olds  Nathan Daniell 《Journal of sports sciences》2013,31(5):459-469

Abstract

The aim of this study was to quantify the anthropometric differences between elite senior Australian rowers and the Australian adult population using three-dimensional (3D) whole-body scanning. The dimensions of senior rowers competing at the 2007–2008 Australian Rowing Championships were compared with those of an age-matched sample of Australian adults. Mass, height, and sitting height were measured before the participants underwent a 3D whole-body scan, with lengths, breadths, girths, cross-sectional and surface areas, and volumes extracted from each scan. Differences in means and variability between the two groups were expressed as standardized effect sizes and ratios of coefficients of variation. Heavyweight rowers were generally much larger than the general population in absolute size, with 3D dimensions and height and mass showing the largest effects. In contrast, lightweight rowers were generally similar or smaller in absolute and proportional size. The dimensions of rowers, especially the lightweights, were also generally less variable than those of the general population. The greatest differences between elite rowers and the general population were seen in dimensions that could not be captured without 3D scanning, such as segmental volumes and cross-sectional areas.  相似文献   

Effect of sand versus grass training surfaces during an 8-week pre-season conditioning programme in team sport athletes     

Martyn John Binnie  Brian Dawson  Mark Alexander Arnot  Hugh Pinnington  Grant Landers  Peter Peeling 《Journal of sports sciences》2013,31(11):1001-1012

Abstract

This study compared the use of sand and grass training surfaces throughout an 8-week conditioning programme in well-trained female team sport athletes (n = 24). Performance testing was conducted pre- and post-training and included measures of leg strength and balance, vertical jump, agility, 20 m speed, repeat speed (8 × 20 m every 20 s), as well as running economy and maximal oxygen consumption (VO_2max). Heart rate (HR), training load (rating of perceived exertion (RPE) × duration), movement patterns and perceptual measures were monitored throughout each training session. Participants completed 2 × 1 h conditioning sessions per week on sand (SAND) or grass (GRASS) surfaces, incorporating interval training, sprint and agility drills, and small-sided games. Results showed a significantly higher (P < 0.05) HR and training load in the SAND versus GRASS group throughout each week of training, plus some moderate effect sizes to suggest lower perceptual ratings of soreness and fatigue on SAND. Significantly greater (P < 0.05) improvements in VO_2max were measured for SAND compared to GRASS. These results suggest that substituting sand for grass training surfaces throughout an 8-week conditioning programme can significantly increase the relative exercise intensity and training load, subsequently leading to superior improvements in aerobic fitness.  相似文献   

Lower limb joint kinetics during the first stance phase in athletics sprinting: three elite athlete case studies     

Neil Edward Bezodis  Aki Ilkka Tapio Salo  Grant Trewartha 《Journal of sports sciences》2013,31(8):738-746

Abstract

This study analysed the first stance phase joint kinetics of three elite sprinters to improve the understanding of technique and investigate how individual differences in technique could influence the resulting levels of performance. Force (1000 Hz) and video (200 Hz) data were collected and resultant moments, power and work at the stance leg metatarsal-phalangeal (MTP), ankle, knee and hip joints were calculated. The MTP and ankle joints both exhibited resultant plantarflexor moments throughout stance. Whilst the ankle joint generated up to four times more energy than it absorbed, the MTP joint was primarily an energy absorber. Knee extensor resultant moments and power were produced throughout the majority of stance, and the best-performing sprinter generated double and four times the amount of knee joint energy compared to the other two sprinters. The hip joint extended throughout stance. Positive hip extensor energy was generated during early stance before energy was absorbed at the hip as the resultant moment became flexor-dominant towards toe-off. The generation of energy at the ankle appears to be of greater importance than in later phases of a sprint, whilst knee joint energy generation may be vital for early acceleration and is potentially facilitated by favourable kinematics at touchdown.  相似文献   

Megatrends or megamistakes? What ever happened to the information society?     

Grant Noble 《The Information Society》2013,29(3):133-146

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The regulation of transnational higher education in Southeast Asia: Case studies of Hong Kong, Malaysia and Australia   总被引：2，自引：0，他引：2  

Grant McBurnie  Christopher Ziguras 《Higher Education》2001,42(1):85-105

The millennium round of the General Agreement on Tradein Services (GATS) underlines issues relating to the regulationof education as an internationally traded service. Transnationaleducation is a key component of such trade. Southeast Asia issomething of a laboratory in the development and regulation oftransnational education. The region combines high demand, keencompetition among providers, and host country regulatory regimesranging from relatively laissez faire to strongly interventionist.This paper examines the approaches of three Southeast Asiangovernments – Hong Kong, Malaysia and Australia – to theregulation of transnational education within their borders. Ineach case the authors provide background on the higher educationsystem, describe the regulatory approaches to transnationaleducation, and analyse the motivations behind regulation. Boththe neoliberal approach of the WTO to trade in educationalservices, and critiques of this approach, are outlined. Theauthors conclude that any attempts to promote global standards orquality principles for transnational education must address themyriad concerns of governments, including consumer protection,advancing national goals and protecting the local system.  相似文献   

Higher prevalence of childhood sexual abuse among Latino men who have sex with men than non-Latino men who have sex with men: data from the Urban Men's Health Study     

Arreola SG  Neilands TB  Pollack LM  Paul JP  Catania JA 《Child abuse & neglect》2005,29(3):285-290

OBJECTIVE: The prevalence of childhood sexual abuse among Latino adult men who have sex with men who live in the US was estimated because a history of childhood sexual abuse increases HIV sexual risk behaviors and other negative health outcomes in adulthood. METHOD: The Urban Men's Health Study is a random-digit telephone probability survey of 2881 adult men who have sex with men (MSM) aged 18 years or older residing in San Francisco, New York, Los Angeles, and Chicago. Self-reported history of childhood sexual abuse was the main outcome measure gathered from 2692 MSM. RESULTS: A significantly higher proportion of Latino MSM reported sexual abuse before age 13 (22%) than did non-Latino MSM (11%). CONCLUSIONS: Latino MSM are twice as likely to report a history of childhood sexual abuse than are non-Latino MSM. Given the association between childhood sexual abuse and increased risk for HIV and other negative health outcomes, health providers must remain vigilant to the possibility of childhood sexual abuse histories among their Latino patients.  相似文献   

Problems of Specialization and Generalization in the Lower Secondary School: the case of Scotland     

Nigel Grant 《Compare》1980,10(2):141-151

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