Martin Van Dijk

The association between objectively measured physical activity and academic achievement in Dutch adolescents: findings from the GOALS study.

The main goal of this study was to investigate the association between objectively measured physical activity and academic achievement in adolescents. Students in Grades 7 and 9 (N = 255) were included. Overall, we found no significant dose-response association between physical activity and academic achievement. However, in Grade 7 total physical activity volume (Total PA) was negatively associated with academic achievement, while moderate-to-vigorous intensity physical activity (MVPA) was negatively associated with both academic achievement and mathematics performance. In contrast, in Grade 9 both Total PA and MVPA were positively associated with mathematics performance. In addition, the overall association between MVPA and academic achievement followed an inverted U-shaped curve. Finally, Total PA was positively associated with executive functioning, while executive functioning in turn mediated the associations between Total PA and both academic achievement and mathematics performance. These results indicate that the association between physical activity and academic achievement in adolescents is complex and might be affected by academic year, physical activity volume and intensity, and school grade.

Learning and navigating in hypertext

Hierarchical menus and tag clouds were compared when learning from hypertext.We captured logging, eye movements and task performance.Tag clouds lead to more focused search without impairing task performance.Focused search showed in less page revisits and longer consulting of tag clouds.Tag clouds support navigation and can facilitate learning from hypertext. As hypertext learning environments (HLE) are widely used in education, it is important to study and know the effects and consequences of its use. HLEs are non-linear which means that students have to develop ways of navigating through them. Thus, developing interfaces that facilitate and even guide navigation is important for learning. Research showed that successful learning in HLEs depends on both learner characteristics and HLE features. This study investigated an HLE navigation feature (navigational support with either a tag-cloud or conventional hierarchical menu), task complexity (fact-finding vs. information-gathering task) and a user characteristic (gender). Results show that neither navigational support nor gender is associated with differences in task performance. However, there are differences in information processing. Participants using a tag clouds looked longer at the navigational support and shorter at the overview pages. Combined with fewer revisits of webpages in the tag cloud condition, this indicates a more focused selection of pages. The deeper processing of information needed for the information-gathering task was reflected in fewer visits to, but longer viewing times of pages. As no differences in task performance were found, tag clouds seem to be as effective for performance as more traditional navigation structures for navigational support.

Cohort profile of the GOALS study: A large-scale research of physical activity in Dutch students.

The GOALS study ( Grootschalig Onderzoek naar Activiteiten van Limburgse Scholieren [ Large-scale Research of Activities in Dutch Students]) was set up to investigate possible associations between different forms of physical activity and inactivity with cognitive performance, academic achievement and mental well-being. It was conducted at a secondary school in the south of the Netherlands. Data collection took place during normal school weeks from October 2011 to March 2012, and 1 year later from October 2012 to May 2013. The study was approved by the local Ethical Committee of the Open University of the Netherlands. All students in grades 7 and 9 of senior general secondary education and university preparatory education were invited to participate ( n = 526). At baseline, a sample of 440 Dutch-speaking adolescents was willing to participate (83.7%). Of these, 344 participated in the follow-up. Physical activity was measured objectively by an Activ PaDOTM accelerometer (Paltechnologies, Glasgow, UK). Cognitive performance was measured by the d2 Test of Attention and the Symbol Digit Modalities Test. Academic achievement was determined using the mean of school grades in Dutch, English and Mathematics. Several well-validated instruments were used to determine mood/depressive symptoms, self-esteem and goal orientation. Information on several covariates such as sex, academic year, school level, ethnicity, socio-economic status, body mass index, pubertal status, smoking, drinking, viewing television, computer use, etc., are available. [ABSTRACT FROM AUTHOR]

Physical activity and school absenteeism due to illness in adolescents

BACKGROUND Knowledge about the beneficial role of physical activity (PA) for health and school performance is growing. Studies investigating the link between PA and school absenteeism due to illness are lacking. Therefore, we investigated associations between habitual PA and school absenteeism due to illness in adolescents and explored whether mental health and cardiovascular fitness mediated this association. METHODS We studied 328 students in grades 7 and 9 (mean age 13.8 years; 49% boys). The PA was measured objectively by an ActivPAL3™ accelerometer attached on the thigh during 1 full week (24 hours/day). Depressive symptoms and self-esteem were self-reported by the Center for Epidemiologic Studies Depression Scale (CES-D) and Rosenberg Self-Esteem Scale, respectively, and included as a proxy for mental health in the analyses. Cardiovascular fitness was measured by the 20-m shuttle-run test. School absenteeism due to illness data was provided by the school administration. RESULTS The PA was not significantly associated with school absenteeism, though there was an indirect association between PA and school absenteeism by cardiovascular fitness. CONCLUSIONS Cardiovascular fitness mediates the association between PA and school absenteeism due to illness. Thus, cardiovascular fitness of students should be improved to reduce school absenteeism due to illness.