Effects of detraining in age-group swimmers performance,energetics and kinematics     

Rodrigo Zacca  Argyris Toubekis  Laura Freitas  Ana Filipa Silva  Rui Azevedo  João Paulo Vilas-Boas 《Journal of sports sciences》2019,37(13):1490-1498

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Time-motion analysis of goalball players in attacks: differences of the player positions and the throwing techniques*     

Lucas Antônio Monezi  Thiago Pinguelli Magalhães  Márcio Pereira Morato  Luciano Allegretti Mercadante  Milton Shoiti Misuta 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(5):470-481

In this study, we aimed to analyse goalball players time-motion variables (distance covered, time spent, maximum and average velocities) in official goalball match attacks, taking into account the attack phases (preparation and throwing), player position (centres and wings) and throwing techniques (frontal, spin and between the legs). A total of 365 attacks were assessed using a video based method (2D) through manual tracking using the Dvideo system. Inferential non-parametric statistics were applied for comparison of preparation vs. throwing phase, wings vs. centres and, among the throwing techniques, frontal, spin and between the legs. Significant differences were found between the attack preparation versus the throwing phase for all player time-motion variables: distance covered, time spent, maximum player velocity and average player velocity. Wing players performed most of the throws (85%) and covered longer distances than centres (1.65 vs 0.31 m). The between the legs and the spin throwing techniques presented greater values for most of the time-motion variables (distance covered, time spent and maximum player velocity) than did the frontal technique in both attack phases. These findings provide important information regarding players’ movement patterns during goalball matches that can be used to plan more effective training.  相似文献   

The impact of exercise training on the lipid peroxidation metabolomic profile and respiratory infection risk in older adults     

Diana Silva  Eduardo Arend  Silvia M. Rocha  Alisa Rudnitskaya  Luís Delgado  André Moreira 《European Journal of Sport Science》2019,19(3):384-393

Aging is associated with oxidative stress that may increase susceptibility to respiratory infections (RIs). We aimed to assess the impact of exercise training on the risk of RIs in older adults and on a targeted metabolomic profile of stress oxidative lipid peroxidation-related metabolites. Methods: In an 8-month clinical trial, 38 participants over 60 years of age were allocated to an exercise group (EG), in which participants underwent 90-min training sessions three times/week(n?=?20), or a control group (CG), in which participants maintained daily physical activities(n?=?18). Daily respiratory symptoms and RIs number and severity were collected. Serum by-products were assessed by comprehensive two-dimensional gas chromatography coupled to mass spectrometry with time of flight analyzer. Serum metabolomic profiling comprised 76 metabolites (alcohols, aldehydes, alkanes, and ketones). Principal components analysis and ANOVA-simultaneous component analysis were used to evaluate the metabolomic profile change. Results: The odds ratio of RIs for the EG was 2.0 CI 95% [0.2;25]. The incidence of RIs was 47% [23;70] in the EG vs. 44%[12;77] in the CG. The metabolomic profiling showed that alkanes and aldehydes classes differed between the EG and the CG before and after intervention. A calibration model showed a relation between the metabolites from four main classes (ketones, alcohols, alkanes and aldehydes) and the prediction of the number of RIs. Conclusion: Moderate exercise training, in older adults, compared with no exercise in controls, did not show a difference in the risk of RIs. A pattern of lipid peroxidation was associated with the number of RIs.  相似文献   

Just for the fun of it: coaches’ perceptions of an exemplary community youth sport program     

Matthew Vierimaa  Jennifer Turnnidge  Mark Bruner  Jean Côté 《Physical Education & Sport Pedagogy》2017,22(6):603-617

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The improvement in walking speed induced by resistance training is associated with increased muscular strength but not skeletal muscle mass in older women     

Leandro Santos  Alex S. Ribeiro  Brad J. Schoenfeld  Matheus A. Nascimento  Crisieli M. Tomeleri  Mariana F. Souza 《European Journal of Sport Science》2017,17(4):488-494

Objective: The purpose of the present study was to analyze whether improvements in fast walking speed induced by resistance training (RT) are associated with changes in body composition, muscle quality, and muscular strength in older women. Methods: Twenty-three healthy older women (69.6?±?6.4 years, 64.95?±?12.9?kg, 1.55?±?0.07?m, 27.06?±?4.6?kg/m²) performed a RT program for 8 weeks consisting of 8 exercises for the whole body, 3 sets of 10–15 repetitions maximum, 3 times a week. Anthropometric, body composition (fat-free mass [FFM], skeletal muscle mass [SMM], legs lean soft tissue [LLST], fat mass), knee extension muscular strength (KE1RM), muscle quality index (MQI [KE1RM/LLST]), and 10-meter walking test (10-MWT) were performed before and after the intervention. Results: Significant (P?<?.05) changes were observed from pre- to post-training for FFM (+1.6%), MQI (+7.2%), SMM (+2.4%), LLST (+1.8%), KE1RM (+8.6%), fat mass (?1.4%), and time to perform 10-MWT (?3.7%). The percentage change in 10-MWT was significantly associated with percentage change in MQI (r?=??0.46, P?=?.04) and KE1RM (r?=??0.45, P?=?.04), however not associated percentage of changes in SMM (r?=?0.01, P?=?.97), LLST (r?=??0.22, P?=?.33), and body fat (r?=?0.10, P?=?.66). Conclusion: We conclude that the improvement in the 10-MWT after an 8-week RT program is associated with increases in lower limb muscular strength and muscle quality, but not with muscle mass or body fat changes in older women.  相似文献   

Conceiving multiple markets through network analysis: evidence from the emergence of the World Music market     

Glaucia Peres da Silva 《Journal of Cultural Economy》2018,11(3):244-260

The idea of multiple markets, conceptualised as a variety of concrete market configurations, was fruitfully developed in the socio-material networks research programme. However, it has not yet been able to solve the following puzzle: the differentiation and specification of multiple markets that exist at the same time in the same place. In this paper, I argue that White’s model of ‘markets from networks’ can contribute to filling this gap, since it is centred on the specification of a market’s structural and cultural boundaries. His model allows for the analysis of concrete market practices intertwined with more abstract concepts of markets formed in discourses that move firms and markets across different levels – from local markets to market sectors. An in-depth analysis of the emergence of the World Music market demonstrates the advantages of employing this model in the analysis of multiple markets.  相似文献   

Book reviews     

M. Bruce Haslam  Edward T. Silva  Manfred Bayer  Stephen Foster  Neil L. Baumgart  John R. Beech  Samuel Kellams  A. G. Watts  Manzoor Ahmed  Robert Myers  Ronald K. Goodenow 《Higher Education》1977,6(3):383-401

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Education for freedom: A look at the pedagogy of Freire     

Alberto Silva 《Prospects》1973,3(1):39-45

In the first two issues of Volume II,Prospects published articles written by Latin American educators for the International Commission on the Development of Education.At a time when several countries of that region are undertaking reforms of their educational systems (see Vol. II, No. 4, the article by Augusto Salazar Bondy), Alberto Silva's analysis, through its emphasis on Paulo Freire's educational methods, seems to be appropriate in order to eopen thought and controversy on this line of thinking. Author of L'École hors de l'École: lÉducation des Masses.  相似文献   

MIRROR EXTENDING AND CIRCULAR SPLINE FUNCTION FOR EMPIRICAL MODE DECOMPOSITION METHOD   总被引：43，自引：0，他引：43  

赵进平  黄大吉 《Journal of Zhejiang University. Science. B》2001,(3)

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Late information pick-up is preferred in basketball jump shooting     

de Oliveira RF  Oudejans RR  Beek PJ 《Journal of sports sciences》2006,24(9):933-940

In this study we examined the timing of optical information pick-up in basketball jump shooting using an intermittent viewing technique. We expected shooters to prefer to look at the basket as late as possible under the shooting style used. Seven experts with a high shooting style and five experts with a low shooting style took 50 jump shots while wearing liquid-crystal glasses that opened and closed at pre-set intervals. In principle, under this constraint, the participants could control when they saw the basket by actively modulating the timing of their movements. Analyses of the phasing of the movements relative to the events defined on the glasses revealed that low-style shooters preferred to see the basket just before the ball passed their line of sight, whereas high-style shooters tended to view the basket from underneath the ball after it passed their line of sight. Thus, most shooters preferred to pick up optical information as late as possible given the adopted shooting style. We conclude that, in dynamic far aiming tasks such as basketball jump shooting, late pick-up of optical information is critical for the successful guidance of movements.  相似文献