Reproducibility of the Internal Load and Performance-Based Responses to Simulated Amateur Boxing.

Thomson, ED and Lamb, KL. Reproducibility of the internal load and performance-based responses to simulated amateur boxing. J Strength Cond Res 31(12): 3396-3402, 2017-The aim of this study was to examine the reproducibility of the internal load and performance-based responses to repeated bouts of a three-round amateur boxing simulation protocol (boxing conditioning and fitness test [BOXFIT]). Twenty-eight amateur boxers completed 2 familiarization trials before performing 2 complete trials of the BOXFIT, separated by 4-7 days. To characterize the internal load, mean (HRmean) and peak (HRpeak) heart rate, breath-by-breath oxygen uptake (V[Combining Dot Above]O2), aerobic energy expenditure, excess carbon dioxide production (CO2excess), and ratings of perceived exertion were recorded throughout each round, and blood lactate determined post-BOXFIT. Additionally, an indication of the performance-based demands of the BOXFIT was provided by a measure of acceleration of the punches thrown in each round. Analyses revealed there were no significant differences (p > 0.05) between repeated trials in any round for all dependent measures. The typical error (coefficient variation %) for all but 1 marker of internal load (CO2excess) was 1.2-16.5% and reflected a consistency that was sufficient for the detection of moderate changes in variables owing to an intervention. The reproducibility of the punch accelerations was high (coefficient of variance % range = 2.1-2.7%). In general, these findings suggest that the internal load and performance-based efforts recorded during the BOXFIT are reproducible and, thereby, offer practitioners a method by which meaningful changes impacting on performance could be identified.

Evaluación de la falla del Hotel Las Olas a consecuencia del terremoto del 22 de abril de 1991 en Costa Rica

Este hotel está ;localizado en la ciudad de Puerto Limón, Costa Rica. La estructura está compuesta de un cuerpo principal de 5 niveles, de planta rectangular muy alargada (aproximadamente 96x7 m2), sin juntas de construcción. Adicionalmente hay un bloque menor de dos niveles y planta rectangular (aproximadamente14x7 m2). El edificio colapso parcialmente durante el sismo a lo largo de tres tramos debido a la falla de dos columnas en el lado occidental del bloque principal. Además, en una columna del bloque menor sufrió una falla importante sin colapsar. El pórtico donde se presentó la falla es sumamente irregular. En tres tramos de planta baja se construyó un muro de mampostería rellena de concreto que arriostró a dos columnas en particular, transformándolas en columnas cortas de 1.4m de altura sumamente rígidas, mientras que el resto de las columnas eran muy flexibles, algunas de doble altura. El resultado fue la falla y total destrucción de las columnas cortas durante el sismo (AU)