Fred Paas is Professor and chair of the research group Educational and Developmental Psychology at the Department of Psychology, Education and Child Studies of Erasmus University Rotterdam in the Netherlands. He is also a Professorial Fellow at the School of Education/Early Start of the University of Wollongong in Australia.    He has been using the theoretical frameworkof cognitive load theory to investigate the instructional control of cognitive load in the training of complex cognitive tasks. His recent research interests include the role of the physical environment in cognition and learning ([see article][]), evolutionary approaches to cognitive load and learning ([see article][see article 1]), and the effects of physical activities (e.g., gestures and exercise) on cognition and learning ([see news item][]).    In 2016 he was recognised as the world's most productive author in the five best journals in the field of educational psychology for the period 2009-2014 ([see article][see article 2]). He is editor-in-chief of the journal *[Educational Psychology Review][]*. In addition, he is part of  the editorial board of several other renowned journals, such as the *Journal of Educational Psychology*. He is a Fellow of the American Educational Research Association.    The practical impact of his research is evidenced by his public lectures ([see example][]), and his role as an advisor for companies, such as [Tinqwise][].    Keywords: EN: Learning, cognition, cognitive load, physical learning environment, mental effort, physical activity, fitness NL: Leren, cognitie, cognitieve belasting, fysieke leeromgeving, mentale inspanning, fysieke activiteit, fitheid [see article]: https://link.springer.com/article/10.1007/s10648-014-9262-6 [see article 1]: https://link.springer.com/article/10.1007/s10648-011-9179-2 [see news item]: http://www.abc.net.au/news/2016-03-31/research-shows-exercise-beneficial-for-learning/7287556 [see article 2]: https://link.springer.com/article/10.1007/s10648-016-9360-8 [Educational Psychology Review]: https://link.springer.com/journal/10648 [see example]: https://content.echo.mq.edu.au:8443/ess/echo/presentation/07723734-070d-48b6-acd1-80e1bedbd8a2 [Tinqwise]: https://tinqwise.nl/en