1Department of General Practice and Primary Care, University of Auckland, Auckland, NEW ZEALAND; 2MRC/UCT Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town and Sports Science Institute of South Africa, Cape Town, SOUTH AFRICA; 3Department of Pediatrics, University of Auckland, Auckland, NEW ZEALAND; 4St Helen's Private Hospital, Hobart, Tasmania, AUSTRALIA; and 5Auckland Family Medical Centre, Auckland, NEW ZEALAND