Body fat measurement in elite sport climbers: Comparison of skinfold thickness equations with dual energy X-ray absorptiometry

Abstract

The aim of this study was to compare equations for estimating percentage body fat from skinfold thickness in elite sport climbers by assessing their agreement with percentage body fat measured using dual-energy X-ray absorptiometry (DXA). Skinfold thickness was measured in a convenience sample of 19 elite sport climbers [9 women and 10 men; mean age 31.2 years (s = 5.0) and 28.6 years (s = 3.6), respectively]. Percentage body fat was estimated using 17 different equations, and it was also measured by DXA. A significant inter-methods difference was observed for all equations, except for Durnin's equation in men (inter-methods difference: ?0.57% and ?0.29%; 1.96 s: 5.56 and 5.23 for Siri's and Brozek's equation, respectively) and women (inter-methods difference: ?0.67% and ?1.29% for Siri's and Brozek's equation, respectively), and for Wilmore's equation using Siri's body fat equation in women (inter-methods difference: ?1.86%). In women, the limits of agreement were lower when using Durnin's equation compared with Wilmore's equation (1.96 s: 3.86% and 5.13%, respectively). In conclusion, of the 17 studied equations, Durnin's equation was the most accurate in estimating percentage body fat in both male and female elite climbers. Therefore, Durnin's equation could be used to assess percentage body fat in elite sport climbers if more accurate methods are not available. The generalizability of the results is limited by the fact that the sample was not selected at random.     

Characteristics of extracurricular physical activity and cognitive performance in adolescents. The AVENA study

Abstract

The aim of this report was to examine the associations between some characteristics (i.e., structure and number) of extracurricular physical activity (EPA) and cognitive performance in adolescents. A total of 1662 adolescents (880 girls; 13.0–18.5 years) from 5 Spanish cities (Granada, Madrid, Murcia, Santander and Zaragoza) were included in this study. Structure (organised and non-organised) and number of EPAs, and participation at vigorous intensity during EPA were self-reported. Cognitive performance (verbal, numeric and reasoning abilities, and an overall score) was measured with the “SRA-Test of Educational Ability”. Results showed that vigorous EPA was positively associated with all cognitive variables. Adolescents who practiced an organised EPA had higher scores in 3 of the 4 cognitive variables than those who practiced a non-organised EPA (all P < 0.05). Likewise, the group who participated in more than one EPA had higher cognitive performance in all variables than the group who participated in only one EPA (all P < 0.05). Regardless of potential confounder variables, including vigorous EPA, both structure and number of EPAs were each other independently associated with cognitive performance. Therefore, structure and number of EPAs may positively influence cognitive performance in adolescents. Participating in multiple, organised EPA may have benefits for cognitive performance.     

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.     

The relationship between approaches to teaching, approaches to e-teaching and perceptions of the teaching situation in relation to e-learning among higher education teachers

This study extends prior research on approaches to teaching and perceptions of the teaching situation by investigating these elements when e-learning is involved. In this study, approaches to teaching ranged from a focus on the teacher and the taught content to a focus on the student and their learning, resembling those reported in previous investigations. Approaches to e-teaching ranged from a focus on information transmission to a focus on communication and collaboration. An analysis of perceptions of the teaching situation in relation to e-learning identified key themes influencing adopted approaches: control of teaching, institutional strategy, pedagogical and technological support, time required, teacher skills for using e-learning, and student abilities and willingness for using learning technology. Associations between these elements showed three groups of teachers: one focusing on transmission of information teaching both face-to-face and online while having a general negative perception of the teaching situation in relation to e-learning; a second focusing on student learning both face-to-face and online while having a general positive perception; and a third presenting unexpected patterns of associations. These results may be helpful for supporting different groups of teachers in employing e-learning in their on-campus units of study. At the same time, further research is proposed for inquiring into specific approaches in different disciplines and different university contexts.     

Virtual Transgenics: Using a Molecular Biology Simulation to Impact Student Academic Achievement and Attitudes

The transgenic mouse model is useful for studying the causes and potential cures for human genetic diseases. Exposing high school biology students to laboratory experience in developing transgenic animal models is logistically prohibitive. Computer-based simulation, however, offers this potential in addition to advantages of fidelity and reach. This study describes and evaluates a computer-based simulation to train advanced placement high school science students in laboratory protocols, a transgenic mouse model was produced. A simulation module on preparing a gene construct in the molecular biology lab was evaluated using a randomized clinical control design with advanced placement high school biology students in Mercedes, Texas (n?=?44). Pre-post tests assessed procedural and declarative knowledge, time on task, attitudes toward computers for learning and towards science careers. Students who used the simulation increased their procedural and declarative knowledge regarding molecular biology compared to those in the control condition (both p?<?0.005). Significant increases continued to occur with additional use of the simulation (p?<?0.001). Students in the treatment group became more positive toward using computers for learning (p?<?0.001). The simulation did not significantly affect attitudes toward science in general. Computer simulation of complex transgenic protocols have potential to provide a ??virtual?? laboratory experience as an adjunct to conventional educational approaches.     

The development of students’ use of additive and proportional methods along primary and secondary school

This study investigates the development of proportional and additive methods along primary and secondary school. In particular, it simultaneously investigates the use of additive methods in proportional word problems and the use of proportional methods in additive word problems. We have also studied the role played by integer and non-integer relationships between the given numbers and the nature of quantities (discrete or continuous) in the development of these phenomena. A test consisting of additive and proportional missing-value word problems was solved by 755 primary and secondary school students (from fourth to tenth grade). The findings indicate that the use of additive methods in proportional situations increased during primary school and decreased during secondary school, whereas the use of proportional methods in additive situations increased along primary and secondary school. Moreover, the presence or absence of integer ratios strongly affects this behavior, but the nature of quantities only has a small influence on the use of proportional methods.     

Relations among student attention behaviors, teacher practices, and beginning word reading skill

The role of student attention for predicting kindergarten word reading was investigated among 432 students. Using Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Rating Scale behavior rating scores, the authors conducted an exploratory factor analysis, which yielded three distinct factors that reflected selective attention. In this study, the authors focused on the role of one of these factors, which they labeled attention-memory, for predicting reading performance. Teacher ratings of attention-memory predicted word reading above and beyond the contribution of phonological awareness and vocabulary knowledge. In addition, the relations between four teacher practices and attention ratings for predicting reading performance were examined. Using hierarchical linear modeling, the authors found significant interactions between student attention and teacher practices observed during literacy instruction. In general, as ratings of attention improved, better kindergarten word reading performance was associated with high levels of classroom behavior management. However, better word reading performance was not associated with high levels of teacher task orienting. A significant three-way interaction was also found among attention, individualized instruction, and teacher task redirections. The role of regulating kindergarten student attention to support beginning word reading skill development is discussed.     

Crime Control Strategies in School: Chicanas’/os’ Perceptions and Criminalization

High schools throughout the United States experience problems with violence, drugs, and crime. School administrators have responded with policies and strategies designed to prevent school violence such as zero tolerance approaches, partnerships with law enforcement agencies, security camera installations, and hiring additional security personnel to monitor students. The purpose of this research is to determine how Chicanas/os and school officials perceive and experience these techniques as part of a broader process of criminalization. In addition, using qualitative data we explore perceptions of safety and experiences with victimization. Qualitative data include interviews (with high school students, school administrators, and security personnel), an evaluation of a Chicana/o-centered program, and participant observations in a predominantly Chicana/o high school located in the Southwest. Findings show some students find the new techniques to be invasive and hostile and others find school security measures as providing a sense of security; and administrators and teachers generally find value in the new approaches. From a LatCrit perspective, we argue that Chicana/o and Mexicana/o experiences are set within a context of racialized space where criminalization is one possible outcome of school security measures.     

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.