The 2019 field was capped at 25,000 runners, and the entry process closed after one week. South African runners constitute the greater part of the field, but many entrants hail from the United Kingdom, Zimbabwe, India, the United States, Brazil, Australia, Botswana, Russia and Swaziland. In all but three runnings since 1988, over 10,000 runners have reached the finish within the allowed 11 or 12 hours. With increased participation since the 1980s, the average finish times for both sexes, and the average age of finishers have increased substantially.