Aspectos éticos en el proceso de enseñanza: Bullying

Tema 7 sobre el bullying de la asignatura del Grado de Ciencias de la Actividad Física y el Deporte, Metodología de la Enseñanza de la Actividad Física y el Deporte

THERMOBIKE: aplicabilidad de la termografía infrarroja en la evaluación de la eficiencia, rendimiento y postura del ciclista

La termografía infrarroja es una técnica de imagen no invasiva y a distancia que permite captar la radiación infrarroja emitida por los cuerpos, y con ello estimar su temperatura superficial. La termografía infrarroja es utilizada en muchos ámbitos, siendo algunos de los más importantes el sector militar y el industrial, seguida de otros sectores como el médico y el veterinario. La aplicación de la termografía infrarroja en el deporte es un tema reciente y existen aspectos a resolver en relación a la metodología, así como a su aplicación en el contexto de la evaluación del rendimiento deportivo en el ciclismo. En este sentido, la presente tesis doctoral tiene la siguiente hipótesis general: la termografía infrarroja puede ser una técnica útil para la evaluación de la eficiencia, rendimiento y postura del ciclista. Para comprobar dicha hipótesis, se plantearon una serie de objetivos específicos englobados en cuatro objetivos generales: 1) analizar la validez de la utilización de la termografía infrarroja como medida de la temperatura de la piel en el ciclismo, 2) estudiar su aplicabilidad en el análisis de la eficiencia del ciclista, 3) evaluar su aplicabilidad como técnica complementaria para el ajuste de la postura del ciclista y 4) utilizar técnicas estadísticas para adaptar el estudio termográfico al ciclismo. Cinco estudios fueron desarrollados para responder a dichos objetivos. Un total de 62 hombres participaron en los estudios. De manera general, la temperatura de la piel fue determinada mediante termografía infrarroja antes de cada test de ciclismo, inmediatamente después de cada test y 10 min después. Otras medidas realizadas en los diferentes estudios fueron el análisis cinemático 2D, el cálculo de la tasa de sudoración corporal global, la medida de la temperatura de la piel mediante sensores de contacto, la medida de la temperatura interna mediante un sensor interno ingerible, medidas de intercambio de gases, y el análisis del confort, dolor y fatiga del ciclista. Las conclusiones más relevantes obtenidas en esta tesis fueron las siguientes. La termografía infrarroja demostró ser una tecnología válida para medir la temperatura de la piel en el ciclismo. Participantes con una mayor activación neuromuscular global con un menor componente de bajas frecuencias en el vasto lateral, presentaron una mejor respuesta termorreguladora a partir de menores aumentos de su temperatura de la piel tras un test incremental. De la misma manera, participantes con una mayor condición física (a partir de una mayor potencia) presentaron una mayor producción de calor interno y con ello una mayor temperatura de la piel. Sin embargo, la aplicación de la termografía infrarroja para estudiar los efectos del cambio de la altura de sillín no pareció ser adecuada. La variación de la temperatura de la piel puede ser una variable válida para estudiar el efecto de una intervención de ejercicio físico, pero es importante tener en cuenta las variables antropométricas durante el reclutamiento de los participantes con el fin de reducir su variabilidad. Finalmente, mediante el análisis factorial, se obtuvieron regiones de interés las cuales presentaron diferencias entre ellas como resultado de la diferente composición de su tejido, actividad muscular y capacidad de sudoración. Todo el contenido de esta tésis ha sido publicado en diferentes artículos científicos y capítulos de libros.Infrared thermography is a safe and non-invasive image technique used to record infrared radiation, and, in particular, the infrared radiation emitted by the human body, which permits estimation of body´s surface temperature. Infrared thermography is used in human applications such as medicine or veterinary science, but also in other fields such, as predictive maintenance of factories, building inspection, military application (e.g. night vision) or control of gases in industry. The application of infrared thermography in sports is still a recent topic and there are many fundamental discussions concerning its different methodological aspects and applications in the context of cycling performance assessment. More specifically in cycling, there are not many thermographic scientific studies specifically aimed at applying it to the sport of cycling, but some preliminary results were obtained about the relationship between skin temperature and cycling efficiency, mainly showing that the more efficient cyclists presented a higher capacity of skin temperature reduction during exercise. The general hypothesis is that infrared thermography may be a useful technique for assessing the efficiency, performance and posture of the cyclist. This dissertation therefore has four general aims: 1) to analyse the validity of infrared thermography in the measurement of skin temperature while cycling, 2) to study its applicability in the assessment of a cyclist’s efficiency, 3) to assess its applicability, as a complementary technique for adjusting the posture of the cyclist and 4) to use statistical techniques aimed at adapting thermographic studies to the sport of cycling. Five studies were developed in order to respond to the general aims. A total of 62 male participants volunteered to participate in the experimental studies. In general, skin temperature was determined using infrared thermography before each cycling test, immediately after, and then 10 min later. Other measurements performed in the different studies were kinematic 2D analysis, whole body sweat rate, skin temperature through thermal contact sensors, core temperature through an ingestible sensor, surface electromyography, gas exchange measurements, and analysis of the comfort, pain and fatigue of the cyclist. Different conclusions were obtained from the studies. Infrared thermography has proven to be a valid technology to measure skin temperature in cycling. Participants with larger overall activation and reduced low frequency component for vastus lateralis activation presented a better adaptive response in their thermoregulatory system by showing fewer changes in skin temperature after the incremental cycling test. In addition, participants of greater physical fitness (i.e. higher peak power output) presented higher heat production and higher skin temperature. However, application of infrared thermography for studying the effects of different saddle heights does not appear to be valid. Skin temperature variation can be a valid measure of the effect of an exercise intervention, but it is important to take into account anthropometrical variables during the recruitment of participants so as to reduce variability. Finally, by using a factorial analysis, coherent regions of interest were obtained and presented differences between them as a result of their different tissue composition, muscular activity and sweat capacity. All the contents referred to in this dissertation have been published in international articles and chapters of books

La resolución por incumplimiento del contrato de franquicia en la jurisprudencia española. Causas y efectos.

La presente tesis aborda el estudio de las principales causas de resolución del contrato de franquicia así como los efectos derivados de dicha resolución cuando la misma se produce como consecuencia del incumplimiento de una de las partes. Se centra en el análisis de la jurisprudencia española recaída en la materia objeto del estudio sin olvidar el estudio de la doctrina española así como el acercamiento a las principales normas dictadas sobre su regulación. Se aproxima también a las aportaciones realizadas por el derecho comparado con el objetivo de poder complementar el estudio realizado así como a otras relaciones contractuales que, en determinados aspectos, pueden tener puntos de similitud con la figura de la franquicia y aportar claridad al objeto del estudio realizado. Se introduce el trabajo con una aproximación general al contrato de franquicia y a la relación contractual desde la perspectiva del derecho de redes y su incardinación en la más genérica categoría de los contratos de distribución así como con una aproximación a la teoría general de la resolución de los contratos para, una vez asentados unos principios generales, poder entrar en el estudio por menoralizado de la resolución por incumplimiento del contrato de franquicia desde un punto de partida más claro

Aspectes ètics en el procés d'ensenyament: Bullying

Tema 7 de l'asignatura Metodologia de l'ensenyament de l'activitat fisica i l'esport. En aquest tema es tracta el bullying

Spectral properties of muscle activation during incremental cycling test

It is uncertain whether fatigue and workload would affect muscle recruitment during cycling. To infer on changes in priority for recruitment of motor units, we assessed the combined effects of fatigue and workload during an incremental cycling test to exhaustion on frequency components of lower limbs muscle activation. Competitive cyclists performed an incremental maximal cycling test while muscle activations were recorded from the right and left vastus lateralis, biceps femoris and gastrocnemius medialis. Muscle activation signals were assessed using frequency band analyses and decomposed into overall, high and low frequency bands. Combined effects from workload/fatigue were assessed using t tests and Cohen¿s effect sizes (ES). There were increases in the overall muscle activation due to increased workload/fatigue for biceps femoris (40% vs. 90%, p<0.01 and ES = 1.85) and vastus lateralis (40% vs. 70%, p=0.01 and ES = 0.96, and 40% vs. 90%, p<0.01 and ES = 2.03, and 70% vs. 90%, p<0.01 and ES = 0.96), but not for gastrocnemius medialis. There was also greater contribution from low frequency component for biceps femoris (40% vs. 90%, p = 0.01 and ES = 1.12). Similar workload/fatigue effects have been observed between lower limbs. In conclusion, incremental cycling test lead to an increase in activation of main knee joint flexors and extensors but not in plantar flexors during cycling. Biceps femoris changes its recruitment profile due to increases in low frequency content

Pràctica. Exemple de sessió. Aprenentatge cooperatiu en educació física

El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de ValènciaEn aquesta presentació es mostra un exemple de sessió per a treballar l'aprenentatge cooperatiu per mitjà de reptes físics cooperatius en educació secundària obligatòria

Importance of static adjustment of knee angle to determine saddle height in cycling

Knee flexion angle is used to determine saddle height during pedaling. However, it is unclear if knee flexion angle at upright standing posture affects measures and interpretation of knee flexion angle during cycling. The objective of this study was to assess the importance of adjusting knee angle during pedaling according to the knee angle at upright posture. Seventeen cyclists performed three 10 min cycling trials at different saddle heights to induce knee flexion angles (40º, 30º or 20º when crank was at the 6 o'clock position). Knee flexion angle was determined at the sagittal plane during cycling using a 2D motion analysis system. Alteration of saddle height was performed by subtracting the knee flexion angle determined during an upright standing posture from the observed knee flexion angle during cycling. Repeatability of knee angles at upright posture in the three trials was very good (ICC=0.73). A reduction in knee flexion angle of 10.6° (95%CI [8.6, 12.6º]) during cycling was found using the adjustment for upright standing posture (p3.0). As a result, saddle height is affected by adjustments based on knee angle measured in upright standing posture. Determining saddle height without adjusting knee angle for upright standing posture could lead to errors with possible effects on performance and/or injury risk

A retrospective international study on factors associated with injury, discomfort and pain perception among cyclists

Although cycling has been associated with overuse/fatigue and acute injuries, there is lack of information regarding associated risk factors and prevention factors. The objective of the study was to determine the factors associated with injury, and perceptions of discomfort and pain in cyclists. A total of 739 cyclists completed an online questionnaire between February and October 2016. The questionnaire acquired information on participant demographics, characteristics related to cycling profile and fitness training, bike components and cycling posture, self-reported perceptions of comfort and pain, and injuries sustained in the last 12 months. Logistic regression models estimated odds ratios (OR) and 95% confidence intervals (95%CI) that examined factors associated with reporting overuse/fatigue injury, acute injury, body discomfort, saddle discomfort, and pain while cycling. Odds of reporting an overuse/fatigue injury increased when the cyclists complemented training with running (OR = 1.74; 95%CI = 1.03-2.91) or swimming (OR = 2.17; 95%CI = 1.19-3.88), and with reported pain while cycling (OR = 1.17; 95%CI = 1.05-3.69) and not cycling (OR = 1.76; 95%CI = 1.07-2.90). Odds of reporting an acute injury increased when biking to work (OR = 1.79; 95%CI = 1.07-2.86), and decreased with increased average cycling speed (1-km/h decrease OR = 0.93; 95%CI = 0.88-0.97), and compared to low-end bike, with the use of mid-range (OR = 0.25; 95%CI = 0.09-0.72) and high-end bike (OR = 0.34; 95%CI = 0.13-0.96). Although body discomfort was only associated with saddle discomfort and the presence of pain during cycling, saddle discomfort was also associated with biking to work (OR = 0.46; 95%CI = 0.22-0.88). Finally, pain perception was associated with a number of factors such as ride to work, core training, cycling experience, saddle discomfort, pain while not cycling. Numerous factors are associated with injury, and perceptions of discomfort and pain in cyclists. Such factors should be considered when developing training routines, bicycle maintenance best practices, and injury prevention programs

Effects of the exercise in the cerebral blood flow and metabolism. A review

In recent years it has been shown that cerebral blood flow is affected by intense exercise, what may even lead to a reduction in the cognitive capacity. This statement is contrary to the traditional belief that cerebral blood flood remains constant and unaltered even when exercise is performed. During physical exercise of moderate intensity, cerebral blood flow increases in the cerebral areas responsible for movement. Moreover, recent studies have observed that cerebral blood flow decreases during high-intensity exercise as a consequence of a local hyperventilation and vasoconstriction of the areas with lower cerebral activity. Traditionally, the glucose has been considered as the main and unique source of energy for the brain. However, new studies are suggesting that as the intensity of exercise increases, the glucose uptake decreases in favour of an increase in the lactate uptake. Finally, Hyperthermia may also play a major role in the cerebral regulation system, since it can provoke central fatigue as well as hypoglycaemia

Effect of cycling specialization on effort and physiological responses to uphill and flat cycling at similar intensity

[EN] Power output is considered one of the best tools to control external loads in cycling, but the relationship between a target power output and the physiological responses may suffer from the effects of road gradient, which is also affected by cyclist specialization. The objective was to determine the effects of cyclist specialization on effort perception and physiological response (heart rate and lactate concentration) while sustaining efforts at similar power output but riding on two different road gradients. Nineteen male competitive road cyclists performed two randomized trials of 10 min at 0% (velodrome) and 10 min at 6% road gradient (field uphill), at an intensity of 10% ± 3% below the individual’s functional threshold power. Cadence was kept between 75 and 80 rpm in both trials and posture remained unchanged during the tests. Heart rate, speed, cadence, power output, blood lactate, and rate of perceived effort were measured for each trial. K-means cluster analyses differentiate uphill (n = 10) and flat specialists (n = 9) according to lactate responses. Flat specialists presented lower heart rate (p < 0.001 and ES = 0.2), perceived exertion (p < 0.01 and ES = 0.7), and blood lactate concentration (p < 0.001 and ES = 0.7) riding on the flat than uphill. Uphill specialists presented lower perceived exertion (p < 0.01 and ES = 0.8) and blood lactate concentration (p < 0.01 and ES = 0.5) riding uphill than on the flat. In conclusion, the combination of cyclist specialization and road gradient affects physiological and effort perception parameters in response to a similar power output demand. These factors deserve attention in training schedules and monitoring performance using power output data.S