Estrategia de paso y frecuencia de ciclo en piragüismo en los JJ.OO. de Pekín

The objective of this study was to analyze the performance patterns from the world�s best paddlers who took part in the Beijing Olympic Games in 2008. The pacing strategy and the evolution of the cycle frequency were analysed from the official results and films recorded from broadcast TV. The analysis database included the 12 Olympics finals (500 and 1000 m). Evolution was similar in all events. The speed decreased through out both distances. There were no differences in pacing strategy between heats or semi-finals and finals. The cycle frequency had their higher values at the beginning of the finals, remained stable in 1000 m events, and decreased along the distance in 500 m events. In conclusion, pacing strategies and cycle frequency evolution followed a negative trend in all the Olympic races, and there were no significant differences in pacing strategy between heats or semi-finals and finals.El objetivo del estudio fue analizar la estrategia de paso y frecuencia de ciclo de los mejores palistas del mundo que participaron en los Juegos Olímpicos de Pekín 2008. Se analizó la estrategia de paso y la evolución de la frecuencia de ciclo de las doce pruebas incluidas en el programa olímpico (500 y 1000 m). La evolución de las variables analizadas fue similar en todas las pruebas. La velocidad disminuyó a lo largo de ambas distancias. No se encontraron diferencias significativas en la estrategia de paso entre eliminatorias y finales. La frecuencia de ciclo obtuvo sus mayores valores al inicio de las finales, permaneciendo estable en las pruebas de 1000 m y disminuyendo en las de 500 m. En conclusión, la estrategia de paso y la evolución de la frecuencia de ciclo respondieron a un patrón decreciente en todas las pruebas, sin diferencias significativas entre pruebas clasificatorias y finales

Anthropometric and equipment characteristics in adolescent sprint kayakers

Los objetivos de este estudio fueron describir las características antropométricas y la configuración del material utilizado por 91 kayakistas españoles adolescentes de 13 y 14 años, de aguas tranquilas y buscar correlaciones entre ambas variables. Se valoraron las características antropométricas y las dimensiones del material de competición de noventa y un kayakistas de aguas tranquilas (45 hombres y 46 mujeres), de 13 y 14 años de edad. Los hombres kayakistas de 14 años presentaron valores superiores a los de 13 años en cuanto a dimensiones antropométricas y del material de competición, mientras que no se encontraron diferencias significativas entre las variables analizadas entre las mujeres kayakistas de 13 y 14 años. La talla y envergadura presentaron las mayores correlaciones con la longitud de la pala y la distancia asiento - reposapiés. La información aportada por este trabajo podría ser de utilidad para ajustar las dimensiones del material de competición, optimizando así el confort y rendimiento en kayakistas jóvenes.The aims of this study were to describe kinanthropometric characteristics and equipment set-up of male and female young kayakers and to look for correlations between both variables. Ninety one young sprint kayakers (45 males and 46 females), aged 13 and 14 years old, were assessed using a battery of 12 anthropometric and 5 equipment dimensions. Comparison between the 13- and 14-year-old kayakers showed that 14-year-old males had greater body and equipment dimensions than their 13-year-old counterparts, whereas there were no significant differences between 13- and 14-year-old female kayakers in both anthropometric and equipment set-up dimensions. Stretch stature and arm span were the variables which greater coefficient correlations showed with total paddle length and seat - feet bar distance. The data presented in this paper may provide important information to adjust equipment sep-up in order to optimise comfort and performance in young kayakers

Sagittal spinal curvatures and pelvic inclination in kayakers

El objetivo del estudio fue comparar la disposición sagital del raquis e inclinación pélvica en diferentes posiciones en kayakistas. A ciento treinta kayakistas entre 15 y 20 años (62 varones y 68 mujeres) se les evaluó, mediante un Spinal Mouse, la disposición angular del raquis torácico, lumbar e inclinación pélvica en bipedestación, sedentación relajada, máxima flexión del tronco en sedentación, test sit-and-reach, posición de base y de ataque en un kayak-ergómetro. La cifosis torácica en la piragua fue menor (p<0,001) que en bipedestación y sedentación relajada. El raquis lumbar se dispuso en inversión lumbar en las posturas de flexión del tronco y sedentación, favorecido por una posición de retroversión pélvica. Las mujeres adoptaron posturas de menor flexión lumbar y pélvica en el kayak-ergómetro. En conclusión, la posición de las mujeres en el kayak-ergómetro se caracteriza por posturas más alineadas del raquis y pelvisThe aim of this study was to compare the sagittal spinal curvatures and pelvic tilt in different positions on kayakers. One hundred and thirty kayakers between 15 and 20 years (62 males and 68 females) participated in this study. Thoracic and lumbar curvatures and pelvic position were evaluated with a Spinal Mouse system in standing position, slumped sitting, maximal trunk bending with knees flexed, sit-and-reach test, base position right entry position and left entry position in a kayak ergometer. Thoracic kyphosis in the kayak-ergometer was more reduced (p<0,001) than standing and slumped sitting. Lumbar spine adopted kyphotic postures when maximal trunk flexion was performed and in the kayak ergometer. This posture was related to posterior pelvic tilt. Females showed lower lumbar and pelvic flexion than males in the kayak ergometer. In conclusion, females adopt more aligned spinal and pelvic postures in the kayak ergometer than malesEste estudio se realizó en el marco de las ayudas de la Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia (II PCTRM 2007-2010) al proyecto nº 11951/PI/09, titulado “Evolution of sagittal spinal curvatures, hamstring extensibility, low back pain, and anthropometric characteristics in elite paddlers

Muscle damage, physiological changes and energy balance in ultra-endurance mountain event athletes

The biological response to ultra-endurance mountain race events is not yet well understood. The aim of this study was to determine the biochemical and physiological changes after performing an ultra-endurance mountain race in runners. We recruited 11 amateur runners (age: 29.7 ± 10.2 years; height: 179.7 ± 5.4 cm; body mass: 76.7 ± 10.3 kg). Muscle damage, lactate concentration, energy balance, rating of perceived exertion (RPE), heart rate (HR), heart rate variability (HRV), body composition changes, and jump performance were analyzed before, during (only lactate, HR, and HRV), and after the race. Athletes completed 54 km in 6 h, 44 min (±28 min). After the race, myoglobin and creatine kinase concentration increased from 14.9 ± 5.2 to 1419.9 ± 1292.1 μg/L and from 820.0 ± 2087.3 to 2421.1 ± 2336.2 UI/L, respectively (p < 0.01). In addition, lactate dehydrogenase and troponin I significantly increased after the race (p < 0.01). Leukocyte and platelet count increased by 180.6% ± 68.9% and 23.7% ± 11.2%, respectively (p < 0.001). Moreover, after the competition, athletes presented a 3704 kcal negative energy balance; a significant increase in RPE values; a decrease in countermovement and squat jump height; and a decrease in body mass and lower limb girths. During the event, lactate concentration did not change and subjects presented a mean HR of 158.8 ± 17.7 beats/min, a significant decrement in vagal modulation, and a significant increase in sympathetic modulation. Despite the relative “low” intensity achieved, ultra-endurance mountain race is a stressful stimulus that produces a high level of muscle damage in the athletes. These findings may help coaches to design specific training programs that may improve nutritional intake strategies and prevent muscle damage.Actividad Física y Deport

TESELA: a new Virtual Observatory tool to determine blank fields for astronomical observations

The observation of blank fields, regions of the sky devoid of stars down to a given threshold magnitude, constitutes one of the typical important calibration procedures required for the proper reduction of astronomical data obtained in imaging mode. This work describes a method, based on the use of the Delaunay triangulation on the surface of a sphere, that allows the easy generation of blank fields catalogues. In addition to that, a new tool named TESELA, accessible through the WEB, has been created to facilitate the user to retrieve, and visualise using the VO-tool Aladin, the blank fields available near a given position in the sky.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Society. 11 pages, 10 figures. Related Web tool accessible at http://sdc.cab.inta-csic.es/tesel

The Herschel view of GAS in Protoplanetary Systems (GASPS). First comparisons with a large grid of models

The Herschel GASPS key program is a survey of the gas phase of protoplanetary discs, targeting 240 objects which cover a large range of ages, spectral types, and disc properties. To interpret this large quantity of data and initiate self-consistent analyses of the gas and dust properties of protoplanetary discs, we have combined the capabilities of the radiative transfer code MCFOST with the gas thermal balance and chemistry code ProDiMo to compute a grid of ≈300 000 disc models (DENT). We present a comparison of the first Herschel/GASPS line and continuum data with the predictions from the DENT grid of models. Our objective is to test some of the main trends already identified in the DENT grid, as well as to define better empirical diagnostics to estimate the total gas mass of protoplanetary discs. Photospheric UV radiation appears to be the dominant gas-heating mechanism for Herbig stars, whereas UV excess and/or X-rays emission dominates for T Tauri stars. The DENT grid reveals the complexity in the analysis of far-IR lines and the difficulty to invert these observations into physical quantities. The combination of Herschel line observations with continuum data and/or with rotational lines in the (sub-)millimetre regime, in particular CO lines, is required for a detailed characterisation of the physical and chemical properties of circumstellar discs