Doctoral defence at School of Education Elvar Smári Sævarsson

Dissertation title: Physical abilities and academic performance. Cross-sectional and longitudinal studies in Icelandic children.

Opponents: Dr. Geir Kåre Resaland, Professor at Western Norway University of Applied Sciences and Dr. Sigrún Ólafsdóttir, Professor at School of Social Science University of Iceland

Doctoral committee:The supervisor Dr. Erlingur S. Jóhannsson, Professor at School of Education, co-supervisor Dr. Þórarinn Sveinsson, Professor at School of Health Science, others in the doctoral committee  were Dr. Sigurgrímur Skúlason and Dr. Erla Svansdóttir.

Chair of Ceremony: Dr. Anna Sigríður Ólafsdóttir, Professor and Dean of Faculty of Health Promotion, Sport and Leisure Studies

Abstract: The academic performance of children has been correlated with their future educational attainment and health and has therefore been viewed as a public health concern. Physical activity and cardiorespiratory fitness are known to exert many beneficial effects on the physical and mental health of children, but the relationship with academic performance remains unclear. The relationship between adiposity and academic performance also remains inconclusive.        

Aim: The main aim of this dissertation was to examine the associations between cardiorespiratory fitness, physical activity, adiposity and academic performance using cross-sectional and longitudinal data.

Methods: This dissertation builds on data from three different studies conducted in Iceland between 2003 and 2015. Physical activity was measured by accelerometers and by a self-report instrument as of frequency weekly sport participation. Cardiorespiratory fitness was assessed by a cycle ergometer, and adiposity was determined by calculating the body mass index (BMI) and body fat percentage via a DXA scan. The results from standardized testing retrieved from the Directorate of Education were used to assess academic performance.

Results: Participating in sports four times or more per week significantly related to better performance in math in 9-year-olds. No cross-sectional or longitudinal associations were identified between objectively measured physical activity and academic performance. A long-term increase in adiposity level was associated with deteriorating academic performance in math, independent of changes in physical activity.

Conclusions: An increase in adiposity from the fourth to 10th grades was accompanied by worsening academic performance. Further studies are required to identify factors that may negatively affect both changes in academics and body composition in school-aged children.