Matthew Ahmadi is a PhD candidate at Queensland University of Technology. He joined the Children’s Physical Activity Research Group at the Centre for Children’s Health Research in August 2016. He has prior experience in community-based physical activity and sleep interventions, and evaluation of objective measures for physical activity and sedentary behaviour. He has an interest in the co-dependence between physical activity, sedentary behaviour, and sleep, and their relationships to health outcomes. Matthew uses an integrative approach to help inform future evidence-based programs and interventions for health behaviour change. The focus of his thesis is the application of machine learning approaches for activity recognition and energy expenditure prediction in free living children and adolescents.