Physical Activity Assessment in Children and Adolescents

This book examines the concepts of physical activity and energy expenditure in humans. The scientific methods of assessing physical activity using subjective methods such as questionnaires, physical activity diaries and interviews are compared with objective methods such as accelerometry, heart-rate monitoring and doubly labeled water. The validity and reliability of these methods are tested in child and adolescent cohorts. It is determined that objective assessment of physical activity has better reliability and validity compared to subjective methods. However, objective methods of assessing physical activity are more expensive compared to subjective methods. For this reason, it may not be feasible to use objective methods for population level studies on physical activity. A compromise would be to use validated questionnaires. This book further compares physical activity levels in European versus African Children. It is determined that African Children are more physical active and less sedentary compared to their European counterparts. Finally, the impact of urbanization on physical activity and adiposity levels in African adolescents is examined.