1. * Department of Physiology, Faculty of Health Sciences, University of Pretoria, South Africa
2. † Sport, Exercise Medicine and Lifestyle Institute (SEMLI), Faculty of Health Sciences, University of Pretoria, South Africa
3. ‡ International Olympic Committee Research Centre of South Africa, Pretoria
4. § Biostatistics Unit, South African Medical Research Council (SAMRC), Cape Town
5. ‖ Statistics and Population Studies Department, University of the Western Cape, Cape Town, South Africa