What is the fine-grained topic of the following text: The comedian set off from Mvezo, the birthplace of Nelson Mandela on Tuesday 23rd February and is trying to finish in Pretoria on Sunday 20th March – where he will run two marathons in one day, in order to pick up distances he missed whilst ill early on in the attempt. Only return the topic.
Comedian's marathon run from Nelson Mandela's birthplace to Pretoria