Timothy A. Brusseau, Ph.D. is Associate Professor and Director of Health and Kinesiology at the University of Utah, Salt Lake City, UT, USA. He is also the Director of the Physical Activity Research Laboratory. Stuart J. Fairclough, Ph.D. is Professor of Physical Activity Education at Edge Hill University, UK. He is also a member of the UK Chief Medical Officers’ Physical Activity Guidelines for Children and Young People Expert Group. David R. Lubans is Professor and National Health and Medical Research Council Fellow in the Priority Research Centre for Physical Activity and Nutrition at the University of Newcastle, Australia.