The reliability, validity and sensitivity of a novel soccer-specific reactive repeated-sprint test (RRST).

PURPOSE: The aim of this study was to determine the reliability, validity and sensitivity of a reactive repeated-sprint test (RRST). METHODS: Elite (n = 72) and sub-elite male (n = 87) and elite female soccer players (n = 12) completed the RRST at set times during a season. Total distance timed was 30 m and the RRST performance measure was the total time (s) across eight repetitions. Competitive match running performance was measured using GPS and high-intensity running quantified (≥ 19.8 km h(-1)). RESULTS: Test-retest coefficient of variation in elite U16 and sub-elite U19 players was 0.71 and 0.84 %, respectively. Elite U18 players' RRST performances were better (P < 0.01) than elite U16, sub-elite U16, U18, U19 and elite senior female players (58.25 ± 1.34 vs 59.97 ± 1.64, 61.42 ± 2.25, 61.66 ± 1.70, 61.02 ± 2.31 and 63.88 ± 1.46 s; ES 0.6-1.9). For elite U18 players, RRST performances for central defenders (59.84 ± 1.35 s) were lower (P < 0.05) than full backs (57.85 ± 0.77 s), but not attackers (58.17 ± 1.73 s) or central and wide midfielders (58.55 ± 1.08 and 58.58 ± 1.89 s; ES 0.7-1.4). Elite U16 players demonstrated lower (P < 0.01) RRST performances during the preparation period versus the start, middle and end of season periods (61.13 ± 1.53 vs 59.51 ± 1.39, 59.25 ± 1.42 and 59.20 ± 1.57 s; ES 1.0-1.1). Very large magnitude correlations (P < 0.01) were observed between RRST performance and high-intensity running in the most intense 5-min period of a match for both elite and sub-elite U18 players (r = -0.71 and -0.74), with the best time of the RRST also correlating with the arrowhead agility test for elite U16 and U18 players (r = 0.84 and 0.75). CONCLUSION: The data demonstrate that the RRST is a reliable and valid test that distinguishes between performance across standard, position and seasonal period

Obelix vs. Asterix : size of US commercial banks and its regulatory challenge

Big banks pose substantial costs to society in the form of increased systemic risk and government bailouts during crises. So the question is: Should regulators limit the size of banks? To answer this question, regulators need to assess the potential costs of such regulations. If big banks enjoy substantial scale economies (i.e., average costs get lower as bank size increases), limiting the size of banks through regulations may be inefficient and likely to reduce social welfare. However, the literature offers conflicting results regarding the existence of economies of scale for the biggest US banks. We contribute to this literature using a novel approach to estimating nonparametric measures of scale economies and total factor productivity (TFP) growth. For US commercial banks, we find that around 73 % of the top one hundred banks, 98 % of medium and small banks, and seven of the top ten biggest banks by asset size exhibit substantial economies of scale. Likewise, we find that scale economies contribute positively and significantly to their TFP growth. The existence of substantial scale economies raises an important challenge for regulators to pursue size limit regulations

The economics of cancer care: longitudinal changes in provider efficiency

Efficiency, Oncology, Performance, Productivity, Competition,

The relationship between physical fitness and shooting accuracy of professional basketball players

The aim of this study was to examine the relationships among physical fitness of professional Bosnianbasketball players (n = 38) and shooting accuracy during one basketball season. A related, secondary aim was toexamine relationships between basketball shooting assessments and competitive shooting accuracy during game play.Physical fitness components included: muscular endurance and aerobic endurance, lower and upper-body power,speed, agility, anaerobic capacity and anaerobic power. The specific basketball shooting accuracy was assessed bystationary and dynamic shooting assessments. Competitive shooting accuracy was represented by data collected duringone basketball season for each player (free throw, field goal, and three-point %). Results of the regression analysesshowed that there were significant positive relationships among shooting assessments and competitive shooting accuracyduring game play. The relationship was stronger when the dynamic shooting tests were applied compared tothe stationary tests. However, few or weak relationships existed among physical fitness components and competitiveshooting accuracy. Only the power tests showed to be good predictors for shooting over longer distances. The findingssupport the inclusion of the dynamic basketball shooting accuracy tests in regular basketball assessment proceduresas a valuable testing instrument.A relação entre aptidão física e precisão de arremesso dos jogadores profissionais de basquetebol.“ Oobjetivo do presente estudo foi identificar a relação entre a condição física de basquetebolistas profissionais bósnios(n=38) na precisão de arremesso no decorrer de uma temporada competitiva. Adicionalmente, pretendeu-se verificara relação entre a avaliação específica e a precisão de arremessos durante os jogos. As variáveis de condição físicaforam as seguintes: resistência de força, resistência aeróbia, potência dos membros inferiores e superiores, velocidade,agilidade, capacidade e potência anaeróbia. A avaliação específica do arremesso foi testada através da utilização dearremessos estáticos e dinâmicos. A precisão dos arremessos durante os jogos foi realizada no decorrer da temporadacompetitiva mediante análise das seguintes variáveis: lance-livre, arremessos de quadra, e percentagem de arremessosde três pontos. As análises de regressão indicaram a existência de uma relação positiva entre as avaliações específicasdos arremessos e a precisão durante os jogos, a qual foi mais forte nas situações de arremessos dinâmicos comparadosaos estáticos. Contudo, as relações existentes entre as variáveis de condição física e a precisão de arremesso duranteos jogos foram menores e pouco significativas. Apenas os testes de potência mostraram ser bons preditores para osarremessos efetuados a longas distâncias. Os resultados obtidos apoiam a inclusão de testes de avaliação da precisãode arremessosrealizados de forma dinâmica em procedimentos regulares de avaliação no basquetebol, constituindo-secomo instrumentos valiosos para ocontrole do rendimento.La relación entre la aptitud física y precisión de tiro de los jugadores profesionales de baloncesto.” El objetivo de este estudio fue examinar la relación entre la condición física de los jugadores profesionales de baloncesto de Bosnia (n=38) y la precisión de tiro durante una temporada de baloncesto. Paralelamente, el objetivo secundario fue examinar las relaciones entre las evaluaciones de lanzamiento de baloncesto y la precisión de tiro durante el partido. Los componentes de la aptitud física incluían: la resistencia muscular y la resistencia aeróbica, la potencia de los miembros inferiores y superiores del cuerpo, la velocidad, la agilidad, la capacidad anaeróbica y la potencia anaeróbica. La pre­cisión específica de tiro de baloncesto se evaluó mediante lanzamiento estático y evaluaciones de tiro en movimiento. La precisión de tiro en competición estuvo representada por los datos recogidos durante una temporada de baloncesto para cada jugador (tiro libre, tiro de campo y triple %). Posteriores análisis de los resultados mostraron que había una significativa relación positiva entre las evaluaciones de tiro y la precisión de tiro durante el partido. La relación era más fuerte cuando las pruebas de tiro en movimiento se compararon con las pruebas de tiro estático. Sin embargo, existían pocas o débiles relaciones entre los componentes de la aptitud física y la precisión de tiro en competición. Sólo las pruebas de potencia mostraron ser buenas predictoras para lanzamientos de mayor distancia. Los resultados apoyan la inclusión de los entrenamientos de precisión de tiro en movimiento en los procedimientos habituales de evaluación de baloncesto, como un valioso instrumento de prueba