El enfoque de los sistemas dinámicos en el aprendizaje del bote en baloncesto en un contexto escolar

En este articulo tratamos de demostrar la teoría de los sistemas dinámicos. Se realizó un diseno cuasiexperimental con dos grupos intactos no equivalentes. Grupo experimental (GE):25, grupo de control (GC):20, con medidas pretest y postest. La variable independiente fue la utilización de unas gafas limitadoras de visión. La variable dependiente fue el tiempo mínimo en la ejecución de test de habilidad en el bote. La unidad didáctica de 7 sesiones era de fundamentos técnicos en baloncesto. Los resultados muestran como se han producido mejoras muy significativas (p-0,001) en el test de bote en zig-zag en el GE, aunque tambien existen mejoras en el grupo de control utilizando un modelo de nsenanza-aprendizaje convencional en EF.This paper attempts to demonstrate the theory of dynamic systems. A quasi-experimental design with two intact, non-equivalent groups was drawn up: an experimental group (EG):25 and a control group (CG): 20; including pre and post-test measurements. The independent variable used was vision-limiting glasses. The dependent variable was the minimum time for performing a dribbling-skills test. The didactic unit of 7 sessions focused on basic basketball techniques. The results measure the EG very significant improvements (p < 0,001) in the zigzag dribbling test, although improvements in the control group using a conventional PE teaching-learning model also existed

Evolución de las tendencias profesionales del titulado en educación física y en ciencias de la actividad física y del deporte desde 1975 hasta la actualidad

En este artículo exponemos como han evolucionado las tendencias y salidas profesionales de los profesionales de la educación física desde los estudios de los diferentes autores que han intentado aportar una visión sobre la cuestión. Desde el primer estudio de Mestre (1975), hasta la actualidad, han surgido diferentes investigaciones en este campo, que han analizado el perfil profesional en base a las demandas laborables, finalizando en las aportaciones del European Network of Sport Sciences Institutes (1999). A modo de conclusión y tras la exposición efectuada, se han elaborado unas directrices acerca de las líneas futuras que regirán el campo laboral en nuestra profesión de las que destacamos la inexistencia de regulación profesional y la trascendencia que ha adquirido en nuestros días la práctica del deporte, que aconsejan y justifican plenamente la necesidad de una regulación completa y sistemática con el rango normativo exigido por el art. 36 de la norma constitucional

Indicaciones y sugerencias sobre el entrenamiento de fuerza y resistencia en ancianos

En este artículo pretendemos exponer las tendencias que existen sobre entrenamiento deportivo en personas mayores. Casi siempre, estamos acostumbrados a asociar el ejercicio físico que practican con actividades lúdicas, de baja o nula intensidad en las que el carácter lúdico es el principal protagonista de la sesión dejando atrás el rendimiento físico. Un correcto trabajo de resistencia o de fuerza bien realizado, a unas cargas de entrenamiento considerables producen una mejora fisiológica que aumenta su independencia funcional, y que mejora, no solo sus condiciones de vida sino que a la larga disminuyen las principales causas de muerte que existenIn this paper we expose the trends that exist about training in greater persons. Almost always, we are accustomed to associate the physical exercise that they practice with games activities . This activities have a low level of instensity and the objetives is the game whithout performance. A good work of endurance or strength adapted training charges produce a physiological improvement that increases their functional independence, and it improves their life quality and it reduces the causes of death that exist in Spain

Evolució de les tendències professionals del titulat en Educació Física i en Ciències de l’Activitat física i de l’Esport des del 1975 fins a l’actualitat

En aquest article exposem com han evolucionat les tendències i sortides professionals dels professionals de l’Educació Física a partir dels estudis dels diferents autors que han intentat d’aportar una visió sobre la qüestió. Des del primer estudi de Mestre (1975), fins a l’actualitat, han sorgit diferents investigacions en aquest camp, que han analitzat el perfil professional en base a les demandes laborals, tot finalitzant en les aportacions de l’European Network of Sport Sciences Institutes (1999). A manera de conclusió i després de l’exposició efectuada, s’han elaborat unes directrius sobre les línies futures que regiran el camp laboral en la nostra professió; en destaquem la inexistència de regulació professional i la transcendència que ha adquirit en els nostres dies la pràctica de l’esport, cosa que aconsella i justifica plenament la necessitat d’una regulació completa i sistemàtica, amb el rang normatiu exigit per l’article 36 de la norma constitucional

Autonomic adaptation after traditional and reverse swimming training periodizations

The objective of the present study was to analyze the autonomic response of trained swimmers to traditional and reverse training periodization models. Seventeen swimmers were divided in two groups, performing a traditional periodization (TPG) or a reverse periodization (RPG) during a period of 10 weeks. Heart rate variability and 50 m swimming performance were analyzed before and after the training programs. After training, the TPG decreased the values of the high frequency band (HF), the number of differences between adjacent normal R-R intervals longer than 50 ms (NN50) and the percentage of differences between adjacent normal R-R intervals more than 50 ms (pNN50), and the RPG increased the values of HF and square root of the mean of the sum of the squared differences between adjacent normal R-R intervals (RMSSD). None of the groups improved significantly their performance in the 50-m test. The autonomic response of swimmers was different depending on the periodization performed, with the reverse periodization model leading to higher autonomic adaption. Complementary, the data suggests that autonomic adaptations were not critical for the 50-m swimming performance

Effects of Sled Towing on Peak Force, the Rate of Force Development and Sprint Performance During the Acceleration Phase

Resisted sprint training is believed to increase strength specific to sprinting. Therefore, the knowledge of force output in these tasks is essential. The aim of this study was to analyze the effect of sled towing (10%, 15% and 20% of body mass (Bm)) on sprint performance and force production during the acceleration phase. Twenty-three young experienced sprinters (17 men and 6 women; men = 17.9 ± 3.3 years, 1.79 ± 0.06 m and 69.4 ± 6.1 kg; women = 17.2 ± 1.7 years, 1.65 ± 0.04 m and 56.6 ± 2.3 kg) performed four 30 m sprints from a crouch start. Sprint times in 20 and 30 m sprint, peak force (Fpeak), a peak rate of force development (RFDpeak) and time to RFD (TRFD) in first step were recorded. Repeated-measures ANOVA showed significant increases (p ≤ 0.001) in sprint times (20 and 30 m sprint) for each resisted condition as compared to the unloaded condition. The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s-1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s-1, p ≤ 0.01). Otherwise, no significant increases were found in Fpeak and TRFD. The RFD determines the force that can be generated in the early phase of muscle contraction, and it has been considered a factor that influences performance of force-velocity tasks. The use of a load up to 20% Bm might provide a training stimulus in young sprinters to improve the RFDpeak during the sprint start, and thus, early acceleration.Actividad Física y Deport

Isokinetic leg strength and power in elite handball players

Isokinetic strength evaluation of the knee flexion and extension in concentric mode of contraction is an important part of the comprehensive evaluation of athletes. The aims of this study were to evaluate the isokinetic knee peak torque in both the extension and flexion movement in the dominant and non-dominant leg, and the relationship with jumping performance. Twelve elite male handball players from the top Spanish handball division voluntary participated in the study (age 27.68 ± 4.12 years; body mass 92.89 ± 12.34 kg; body height 1.90 ± 0.05 m). The knee extensor and flexor muscle peak torque of each leg were concentrically measured at 60º/s and 180º/s with an isokinetic dynamometer. The Squat Jump and Countermovement Jump were performed on a force platform to determine power and vertical jump height. Non-significant differences were observed between legs in the isokinetic knee extension (dominant= 2.91 ± 0.53 Nm/kg vs non-dominant = 2.70 ± 0.47 Nm/kg at 60º/s; dominant = 1.90 ± 0.31 Nm/kg vs non-dominant = 1.83 ± 0.29 Nm/kg at 180º/s) and flexion peak torques (dominant = 1.76 ± 0.29 Nm/kg vs non-dominant = 1.72 ± 0.39 Nm/kg at 60º/s; dominant = 1.30 ± 0.23 Nm/kg vs non-dominant = 1.27 ± 0.35 Nm/kg at 180º/s). Low and non-significant correlation coefficients were found between the isokinetic peak torques and vertical jumping performance (SJ = 31.21 ± 4.32 cm; CMJ = 35.89 ± 4.20 cm). Similar isokinetic strength was observed between the legs; therefore, no relationship was found between the isokinetic knee flexion and extension peak torques as well as vertical jumping performance in elite handball players.Actividad Física y Deport

Interrelationship between different loads in resisted sprints, half-squat 1RM, and kinematic variables in trained athletes

Resisted sprint running is a common training method for improving sprint-specific strength. It is well-known that an athlete's time to complete a sled-towing sprint increases linearly with increasing sled load. However, to our knowledge, the relationship between the maximum load in sled-towing sprint and the sprint time is unknown, The main purpose of this research was to analyze the relationship between the maximum load in sled-towing sprint, half-squat maximal dynamic strength and the velocity in the acceleration phase in 20-m sprint. A second aim was to compare sprint performance when athletes ran under different conditions: un-resisted and towing sleds. Twenty-one participants (17.86±2.27 years; 1.77±0.06 m and 69.24±7.20 kg) completed a one repetition maximum test (1 RM) from a half-squat position (159.68±22.61 kg) and a series of sled-towing sprints with loads of 0, 5, 10, 15, 20, 25, 30% body mass (Bm) and the maximum resisted sprint load. No significant correlation (P<0.05) was found between half-squat 1 RM and the sprint time in different loaded conditions. Conversely, significant correlations (P<0.05) were found between maximum load in resisted sprint and sprint time (20-m sprint time, r=−0.71; 5% Bm, r=−0.73; 10% Bm, r=−0.53; 15% Bm, r=−0.55; 20% Bm, r=−0.65; 25% Bm, r=−0.44; 30% Bm, r=−0.63; MaxLoad, r= 0.93). The sprinting velocity significantly decreased by 4–22% with all load increases. Stride length (SL) also decreased (17%) significantly across all resisted conditions. In addition, there were significant differences in stride frequency (SF) with loads over 15% Bm. It could be concluded thatthe knowledge of the individual maximal load in resisted sprint and the effects on the sprinting kinematic with different loads, could be interesting to determinate the optimal load to improve the acceleration phase at sprint running.Actividad Física y Deport

Body composition and fitness in elite Spanish children tennis players

The aims of this study were to describe body composition and physical fitness changes during a whole-season in elite children tennis players. A total of 7 elite children tennis players participated in the study. Whole body composition by dual energy X-ray absorptiometry (DXA) and physical fitness were assessed during a season. Subjects increased lean and bone percentage, and decreased abdominal fat and total body fat percentage (all p<0.05). From month1 to month5 subjects improved in handgrip right test, standing broad jump and 20m shuttle run test (all p<0.05). From month5 to month10 there were not significant differences in physical fitness, although some showed a decline (back-saver sit and reach and shuttle run 20 m test). During the whole season, subjects decreased sit and reach in the left leg, but increased handgrip dominant test and standing broad jump (all p<0.05). During a season, children tennis players increased lean and bone percentage, and decreased abdominal and total fat percentage (all p<0.05). However, waist circumference and waist to height ratio were not useful to detect body composition changes. In addition, there were asymmetric changes in fitness (maximal isometric strength increased in the dominant hand and flexibility decreased in the contra lateral leg)