The 13th edition of the 70.3 IRONMAN South Africa is taking place on Sunday.
1500 athletes from across the world are in East London to compete in the second hardest half-ironman course in the world.
The professional men go off first closely followed by the professional women.
The event is made up of a 1.9 km swim, 90 km cycle section and it finishes with a 21.1 km run.
The weather and hilly conditions in East London make for a challenging event which will make it difficult for record-breaking or personal best times.
Defending champions for both the male and female categories are back this year. Bradley Weiss and Annah Watkinson are looking for a second round of top honours.
Click on the video below: