1 Wits Sport and Health (WiSH), School of Clinical Medicine, Faculty of Health Sciences, Wits University, Johannesburg, Gauteng, South Africa jpat@mweb.co.za.
2 Sport and Exercise Medicine Research Centre, La Trobe University, Melbourne, Victoria, Australia.
3 Public Health and Family Medicine, University of Western Ontario Schulich School of Medicine and Dentistry, London, Ontario, Canada.
4 Department of Family Medicine, University of Washington, Seattle, Washington, USA.