1. Sport, Exercise Medicine and Lifestyle Institute (SEMLI), Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
2. IOC Research Centre, Pretoria, South Africa
3. South African Rugby Union, Tygerberg, South Africa
4. Health, Physical Activity, Lifestyle, and Sport (HPALS) Research Centre, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
5. Biostatistics Research Unit, South African Medical Research Council (SAMRC), Cape Town, South Africa
6. Statistics and Population Studies, University of the Western Cape, Cape Town, South Africa