Jump height loss as an indicator of fatigue during sprint training

This study analysed the acute mechanical and metabolic responses to a sprint training session focused on maintaining maximal speed until a given speed loss was reached. Nine male high-level sprinters performed 60 m running sprints up to a 3% in speed loss with 6 min rests between sets. Mechanical responses (countermovement jump (CMJ) height and speed loss) and metabolic responses (blood lactate and ammonia concentrations) were measured pre-exercise and after each set was performed. Jump height loss showed almost perfect relationships with both lactate (r = 0.91) and ammonia (r = 0.91) concentrations. In addition, nearly perfect relationships were observed for each athlete between CMJ height loss and lactate (r = 0.93–0.99) and ammonia (r = 0.94–0.99). Very large correlations were found between speed loss and lactate (r = 0.83), and ammonia (r = 0.86) concentrations. Furthermore, close relationships were observed for each athlete between speed loss and lactate (r = 0.86–0.99), and ammonia (r = 0.88–0.98). These results suggest that the CMJ test may allow more accurate setting of training loads in sprint training sessions, by using an individualised sprint dose based on mechanical and physiological responses rather than a standard fixed number of sprints for all athletes.     

Price-effectiveness: pharmacoeconomics,value and the right price for HPV vaccines

ABSTRACT

Drawing on a pragmatist approach to pricing, this article discusses the impact of cost-effectiveness analysis (CEA) in the pricing strategies of pharmaceutical companies. Through an analysis of the human papillomavirus (HPV) vaccination, this article illustrates the strategic appropriation of evidence-based medicine (narratives and practices) that pharmaceutical companies have undertaken to enhance the value of their products. While governments are concentrated on the measurement of costs and efficiency (cost-effectiveness), companies attempt to find the threshold of effectiveness that supports their estimation of value. I have called such mode of calculation, price-effectiveness. Pharmaceutical companies engage in different ways with CEA in devising their own price strategies. First, CEA is used as an instrument to raise HPV vaccines as a matter of interest for health authorities. Second, companies produce models to maximise the effectiveness of their products. Third, the expense side of CEA has opened an opportunity to represent some conditions as diseases in order to increase the potential value of the vaccine, expressed in a higher price. Debates and practices of pricing offer a unique opportunity to trace how particular forms of quantification have become the common ground in the demonstration of value in healthcare and the adaptation of companies.     

Validity of a single lactate measure to predict fixed lactate thresholds in athletes

This study aimed to validate the use of a single blood lactate concentration measure taken following a 12 km h^?1 running stage (BLC₁₂) to predict and monitor fixed blood lactate concentration (FBLC) thresholds. Three complementary studies were undertaken. Study I: the relationships between BLC₁₂ and the running speeds at FBLC of 3 mmol L^?1 (S3mM) and 4 mmol L^?1 (S4mM) measured during a multistage running field test were examined in 136 elite athletes. Study II: data from 30 athletes tested one year apart were used to test the predictive capacity of the equations obtained in Study I. Study III: 80 athletes were tested before and after an intensified training period to examine whether training-induced changes in FBLC thresholds could be predicted and monitored by BLC₁₂. Study I: BLC₁₂ was significantly (P < 0.001) and inversely related to S3mM (R² = 0.89) and S4mM (R² = 0.95). Study II: prediction models yielded robust correlations between the estimated and measured FBLC thresholds (r = 0.94–0.99; P < 0.001). Study III: estimated changes predicted actual training-induced changes in FBLC thresholds (r = 0.81–0.91; P < 0.001). This study gives empirical support to use a single lactate measure during a sub-maximal running field test as a simple, low-cost and practical alternative to FBLC thresholds in athletes.     

Short-term performance peaking in an elite cross-country mountain biker

ABSTRACT

Endurance athletes usually achieve performance peaks with 2–4 weeks of overload training followed by 1–3weeks of tapering. With a tight competition schedule, this may not be appropriate. This case investigates the effect of a 7-day overload period including daily high-intensity aerobic training followed by a 5-day step taper between two competitions in an elite cross-country mountain biker. Pre-test peak oxygen consumption was 89 ml·kg^?1·min^?1, peak aerobic power 6.8 W·kg^?1, power output at 2 mmol·L^?1 blood lactate concentration 3.9 W·kg^?1, maximal isometric force 180 Nm and squat jump 21 cm. During overload, perceived leg well-being went from normal to very heavy. On day 1 after overload, vastus lateralis and vastus medialis EMG_mean activity was reduced by 3% and 7%, respectively. Other baseline measurements were reduced by 3–7%. On day 4 of the taper, he felt that his legs were good and all measurements were 3–7% higher than before overload. On day 6 after the taper, his legs felt very good. This case shows that an elite mountain biker (11th in UCI World Cup one week prior to the pre-test) could achieve a rather large supercompensation by using a 12-day performance peaking protocol.     

Embodied cognition as grounding for situatedness and context in mathematics education

In this paper we analyze, from the perspective of 'Embodied Cognition', why learning and cognition are situated and context-dependent. We argue that the nature of situated learning and cognition cannot be fully understood by focusing only on social, cultural and contextual factors. These factors are themselves further situated and made comprehensible by the shared biology and fundamental bodily experiences of human beings. Thus cognition itself is embodied, and the bodily-grounded nature of cognition provides a foundation for social situatedness, entails a reconceptualization of cognition and mathematics itself, and has important consequences for mathematics education. After framing some theoretical notions of embodied cognition in the perspective of modern cognitive science, we analyze a case study – continuity of functions. We use conceptual metaphor theory to show how embodied cognition, while providing grounding for situatedness, also gives fruitful results in analyzing the cognitive difficulties underlying the understanding of continuity. This revised version was published online in July 2006 with corrections to the Cover Date.     

Programa para el aprendizaje del lenguaje en grupo de niños deficientes mentales medios

RESUMEN

El artículo propone un programa para la enseñanza del lenguaje a niños deficientes mentales destinado al educador que trabaje en esta área. Algunos criterios básicos de actuación al elaborar el programa son la utilización progresiva del juego, la utilización del contraste y la fórmula binaria para aprender los sonidos, el uso de la asociación y la referencia constante al contexto cotidiano del niño. El programa se divide en seis niveles. El primer nivel es una iniciación al aprendizaje del lenguaje. El segundo va dirigido a niños capaces de reconocer y nombrar algunos objetos y con un nivel mínimo de comprensión. Los niños del tercer nivel utilizan más vocabulario y reconocen e identifican imágenes de los objetos. En el cuarto nivel se trabaja con niños que utilizan la frase simple y tienen integrada la comprensión de la imagen pura. El quinto nivel se dirige a niños con cierta capacidad de comunicación, aunque con agramatismo. Por último los niños del sexto nivel comienzan a trabajar en la lectoescritura.     

Beliefs about learning and enacted instructional practices: An investigation in postsecondary chemistry education

While research on and development of evidence‐based instructional practices (EBIPs) in STEM education has flourished, implementation of these practices classrooms has not been as prolific. Using the teacher‐centered systemic reform model as a framework, we explore the connection between chemistry instructors’ beliefs about teaching and learning and self‐efficacy beliefs, and their enacted classroom practices. Postsecondary chemistry faculty present a unique population for the study because of their role in teaching prerequisite courses, such as general and organic chemistry, which are key to many science major fields. A measure of teacher beliefs and self‐efficacy was administered to a national survey of postsecondary chemistry faculty members. Instructional practices used in a chemistry course were also collected via self‐report. While instructional practices were not directly observed, a cluster analysis of our data mirrors patterns of instructional practices found in observation‐based studies of chemistry faculty. Significant differences are found on teacher thinking and self‐efficacy measures based on enacted instructional practices. Results support the hypothesized connection between beliefs and instructional practice on a larger scale than in previous studies of this relationship, bolstering the evidence for the importance of this relationship over previously criticized results. These results present a call for reform efforts on fostering change from its core, that is, the beliefs of those who ultimately adopt EBIPs. Dissemination and design should incorporate training and materials that highlight the process by which faculty members interpret reformed practices within their belief system, and explore belief change in the complex context of education reform.     

Group work: Prospective teachers’ acquisition of transversal competences

The current training model being used in higher education advocates the acquisition of competences aimed at providing students with all-round training that will enable them to tackle their future work responsibilities effectively. This encompasses a number of different competences, most notably the transversal kind, especially in view of the important role they play in shaping the profile of any professional individual. The active learning methods applied to group work have shown to be the most suitable for achieving these competences. From this perspective, and considering their relevance, we present the results of a study that addresses the perceptions held by students from Education Degrees regarding the extent to which transversal competences are acquired by implementing active learning methods. The students perceive group work as a dynamic that teaches them how to be more self-critical and committed to group-oriented tasks, thus encouraging communication skills, personal relationships and motivation. However, a lesser degree of acquisition has been recorded in other equally important competences. As such, it is necessary to promote these learning methods from the start, carefully designing and planning the curriculum structure as well as the tasks to be performed in order to avoid any negative implications that may arise.     

A general result on non-existence of finite-time stable equilibria in fractional-order systems

It is well known that a fractional-order system with a continuous right hand side does not have finite-time stable equilibria, but the discontinuous case has remained elusive in literature. Thus, based on novel mathematical tools, recently published in literature, it is demonstrated that attaining finite-time stable equilibria is not possible for a fractional-order system, not even in the case of an impulsive or discontinuous feedback. In consequence, it is demonstrated that, for a fractional-order system, a Lyapunov stable equilibrium cannot be at the same time finite-time stable.     

Reflection-on-action learning through traditional games. The case of la pelota sentada (sitting ball) / Aprendizaje basado en la reflexión sobre la acción a través de los juegos tradicionales. El caso de la pelota sentada

Traditional paradoxical games enable democratic social encounters as well as reflective skills to be fostered among students. The rules of these games, of which the game pelota sentada (sitting ball) is an example, afford players autonomy to decide either to cooperate with other participants (to release or keep others free) or to oppose them (to capture free players). The aim of this study was to investigate the reflection-on-action about decisions (strategies), relationships and emotions of the participants in the game sitting ball when in the role of free player in possession of the ball. Undergraduate degree students (n = 106) in physical activity and sport sciences took part. After the game, the players answered reflection-on-action open-ended and close-ended questions about their strategies, relationships and emotions. Four experts followed a validated directed and summative approach to the content analysis of 742 comments, using ATLAS.ti software. The findings highlight that decisions, relationships and emotions are distinct yet intertwined dimensions of the same phenomenon: motor conduct in the game pelota sentada (sitting ball).