1965-67     Research Associate, Laboratory for Human Performance Research, Institute for  Science and Engineering, The Pennsylvania State University, University Park, Pa.

1967-69     Assistant Professor of Applied Physiology, Ibid

1969-81     Director, Department of Research and Sports Medicine, Wingate Institute for Physical Education and Sport, Israel

1975-77     Scientific Director, Wingate Institute, Israel

1977     Program Coordinator – Physiological, Clinical and Kinesiological Aspects of Exercise, Post-Graduate Medical School, Tel-Aviv University, Israel

1978-80     Visiting Professor in Internal Medicine and Pediatrics, McMaster University,  Hamilton, Ontario, Canada

1981-2005     Professor of Pediatrics, and Director, Children’s Exercise and Nutrition Centre, McMaster University and Chedoke-McMaster Hospitals, Hamilton, Ontario

1983-84     Associate Staff – Chedoke-McMaster Hospitals

1984-2005     Active Staff – Chedoke-McMaster Hospitals

1989     Visiting Professor, Department of Human Biology, University of Limburg, Maastricht, The Netherlands

1997     Visiting Professor, School of Human Movement Studies, Queensland University of Technology, Queensland, Australia (September 1 – November 3, 1997)

1998     Visiting Professor, School of Education, University of Exeter, Exeter, U.K. (January 1 – February 20, 1998)

2003–2005      Professor Emeritus, Pediatrics, McMaster University and Director, Children’s Exercise & Nutrition Centre, Hamilton Health Sciences