Relationship between physiological parameters and performance during a half-ironman triathlon in the heat

Abstract

Triathlon is a popular outdoor endurance sport performed under a variety of environmental conditions. The aim of this study was to assess physiological variables before and after a half-ironman triathlon in the heat and to analyse their relationship with performance. Thirty-four well-trained triathletes completed a half-ironman triathlon in a mean dry temperature of 29 ± 3ºC. Before and within 1 min after the end of the race, body mass, core temperature, maximal jump height and venous blood samples were obtained. Mean race time was 315 ± 40 min, with swimming (11 ± 1%), cycling (49 ± 2%) and running (40 ± 3%) representing different amounts of the total race time. At the end of the competition, body mass changed by ?3.8 ± 1.6% and the change in body mass correlated positively with race time (r = 0.64; P < 0.001). Core temperature increased from 37.5 ± 0.6ºC to 38.8 ± 0.7ºC (P < 0.001) and post-race core temperature correlated negatively with race time (r = ?0.47; P = 0.007). Race time correlated positively with the decrease in jump height (r = 0.38; P = 0.043), post-race serum creatine kinase (r = 0.55; P = 0.001) and myoglobin concentrations (r = 0.39; P = 0.022). In a half-ironman triathlon in the heat, greater reductions in body mass and higher post-competition core temperatures were present in faster triathletes. In contrast, slower triathletes presented higher levels of muscle damage and decreased muscle performance.     

Intermittent hypoxia exposure in a hypobaric chamber and erythropoietin abuse interpretation

Abstract

The aim of this study was to assess the effect of intermittent hypoxia exposure on direct and indirect methods used to evaluate recombinant human erythropoietin (rhEPO) misuse. Sixteen male triathletes were randomly assigned to either the intermittent hypoxia exposure group (experimental group) or the control normoxic group (control group). The members of the experimental group were exposed to simulated altitude (from 4000 to 5500 m) in a hypobaric chamber for 3 h per day, 5 days a week, for 4 weeks. Blood and urine samples were collected before and after the first and the final exposures, and again 2 weeks after the final exposure. While serum EPO significantly increased after the first [from a mean 8.3 IU · l^?1 (s = 3.2) to 16.6 IU · l^?1 (s = 4.7)] and final exposures [from 4.6 IU · l^?1 (s = 1.4) to 24.8 IU · l^?1 (s = 9.3)], haemoglobin, percentage of reticulocytes, and soluble transferrin receptor were not elevated. Second-generation ON/OFF models (indirect rhEPO misuse detection) were insensitive to intermittent hypoxia exposure. The distribution of the urinary EPO isoelectric profiles (direct rhEPO misuse detection) was altered after intermittent hypoxia exposure with a slight shift towards more basic isoforms. However, those shifts never resulted in misinterpretation of results. The intermittent hypoxia exposure protocol studied did not produce any false-positive result for indirect or direct detection of rhEPO misuse in spite of the changes in EPO serum concentrations and urinary EPO isoelectric profiles, respectively.     

Progression in Complexity: Contextualizing Sustainable Marine Resources Management in a 10th Grade Classroom

Sustainable management of marine resources raises great challenges. Working with this socio-scientific issue in the classroom requires students to apply complex models about energy flow and trophic pyramids in order to understand that food chains represent transfer of energy, to construct meanings for sustainable resources management through discourse, and to connect them to actions and decisions in a real-life context. In this paper we examine the process of elaboration of plans for resources management in a marine ecosystem by 10th grade students (15–16 year) in the context of solving an authentic task. A complete class (N = 14) worked in a sequence about ecosystems. Working in small groups, the students made models of energy flow and trophic pyramids, and used them to solve the problem of feeding a small community for a long time. Data collection included videotaping and audiotaping of all of the sessions, and collecting the students’ written productions. The research objective is to examine the process of designing a plan for sustainable resources management in terms of the discursive moves of the students across stages in contextualizing practices, or different degrees of complexity (Jiménez-Aleixandre & Reigosa International Journal of Science Education, 14(1): 51–61 2006), understood as transformations from theoretical statements to decisions about the plan. The analysis of students’ discursive moves shows how the groups progressed through stages of connecting different models, between them and with the context, in order to solve the task. The challenges related to taking this sustainability issue to the classroom are discussed.     

Developing Generic Competences in the European Higher Education Area: a proposal for teaching the principles of economics

The participation of Spain in the European Higher Education Area (EHEA) involves a number of important challenges for academics. Adapting to an educational model that is characterised by competence-based teaching is a difficult task, yet it is of paramount importance in the context of current reforms. In an educational system in which the traditional lecture prevails, learning-centred teaching represents a major cultural change with significant consequences. The objective of this study is to offer economics lecturers some practical techniques for use in the classroom. Specifically, it includes suggestions for the planning, preparation and teaching of lectures, seminars, tutorials, case studies, debates, and computer-based learning. It also provides practical advice on student assessment.     

Critical Communicative Methodology: including vulnerable voices in research through dialogue

This article describes how Critical Communicative Methodology (CCM) has been used successfully to analyse educational inequalities in ways that generate real transformation towards social justice. We begin by arguing that educational research today should employ new methodological approaches that can ensure the inclusion of different voices in social science research and the production of knowledge that transforms social exclusion. We then analyse the main epistemological positions of CCM, based on Habermas’ communicative action theory, and explain how it was implemented in the European Union-funded INCLUD-ED project. Finally, we illustrate how INCLUD-ED has had a social and political impact and we argue that research with vulnerable groups, based on the principles of CCM, can generate social and educational transformation.     

‘What's next for masculinity?’ Reflexive directions for theory and research on masculinity and education

Research on masculinity has become an important area of gender and education that includes a wide range of empirical concerns and theoretical approaches. This article identifies a number of studies that are asking questions about the conceptual usefulness of masculinity within educational contexts. The first section explores how educational researchers are beginning to suggest alternative ways that hegemonic masculinity may be configured. The second section draws upon work that interrogates the disconnection of gender from sex. Such work considers the importance of understanding schooling worlds through an untethering of gender categories from physical bodies. The third section suggests the possibility of a post-masculinity position by exploring research that questions the viability of masculinity as a conceptual frame to understand gender. In conclusion, the paper argues that such developments can be used heuristically to inform the critical reflexiveness of future research in the area.     

The impact of the Programme for International Student Assessment on academic journals

The aim of this study is to assess the impact of PISA (Programme for International Student Assessment) on international scientific journals. A bibliometric analysis was conducted of publications included in three main scientific publication databases: Eric, EBSCOhost and the ISI Web of Knowledge, from 2002 to 2010. The paper focused on four main questions: who carried out these studies, in which academic journals have the articles been published, what has been the evolution of these publications and what were the main article topics? The study concludes that PISA has had a considerable impact on the scientific research, reflected primarily by university-based authors from the areas of education and social sciences analysing student performance. The evolution since 2007 seems to indicate that more articles will be published in coming years through the initiative of researchers (rather than the editorial boards), even from other scientific areas, thus increasing the number of topics of analysis.     

回顾与反思:小学数学教科书研究综述(2001～2010)

2001年《全日制义务教育数学课程标准(实验稿)》颁布,宣告义务教育数学课程改革正式启动,课程改革至今已走过10年历程,虽步履维艰,但成果颇丰。对2001至2010年间的小学数学教科书研究的文献进行分类综述,研究发现:关于小学数学教科书的研究主要集中在比较、内容、结构、呈现方式、使用、历史、文化及与其相关的研究等方面。     

Teachers’ moral values and their interpersonal relationships with students and cultural competence

This study explored whether and how teachers’ beliefs about moral values are reflected in the student-teacher relationships (i.e. levels of control and affiliation in teachers’ and students’ perceptions of this relationship), and in teachers’ cultural competence. A positive association was found between teachers’ paternalist beliefs and their own perceptions of control. A negative association was found between teachers’ liberal beliefs and students’ perceptions of affiliation. Positive associations were found between teachers’ liberal beliefs and the metacognitive and motivational components of cultural competence. We discuss the implications for preparation of teachers to reflect on the manifestations of their beliefs in practice.