1. Sport, Exercise Medicine and Lifestyle Institute (SEMLI), Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
2. Section Sports Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
3. International Olympic Committee (IOC) Research Centre, Pretoria, South Africa
4. Comrades Marathon Pietermaritzburg, South Africa
5. Biostatistics Unit, South African Medical Research Council, Cape Town, South Africa
6. Statistics and Population Studies Department, University of the Western Cape, Cape Town, South Africa