Johannesburg - A 28-year-old man from Midrand died during a long-distance obstacle race in Centurion, Pretoria, on Saturday, the organisers said in a statement.
"A participant taking part... collapsed, and despite resuscitation from a full medical team, unfortunately passed away," they said on Sunday.
The event was the second of eight in the Warrior Series, with race distances ranging from 800m for children to 20km for adults.
The man had taken part in the 10km race for rookies, and collapsed before the halfway mark.
According to the series website, the course took runners through veld, forest, mud, and rivers.
“We are profoundly saddened by the loss of one of our warriors,” the organisers said.
His name would be released on Monday.