A tribute to anti-apartheid revolutionary, politician and philanthropist Nelson Mandela, Izzard plans to run a total of 27 marathons over 27 days to represent the 27 years Mandela spent in prison.
Izzard is no stranger to endurance, having covered the length of the UK in 2009, running 43 marathons in 51 days - a total of almost 2000 kilometres in seven weeks.
He began his South African journey on 24th February in the Eastern Cape. Throughout the challenge Izzard has been visiting communities, organisations and families that have all been helped by the work of Sport Relief and exploring the home country of Mandela.
So far, Izzard's fastest marathon has been 5:34 and his slowest has been 9:45.
'I’ve adopted lots of different types of marathons,' he told Runner's World. '1. Split marathons (running 21K in the morning, resting during the midday sun and finishing late afternoon) 2. Recovery marathons at a steady pace with no time pressure. 3. Time trials - quickest was 5 hours 34 minutes on Sunday 13th).
Wearing Inov Race Ultra 290's on his feet, the endurance runner has followed a strict diet to get him across South Africa. 'I have been eating porridge and honey before on most days, also sometimes boiled eggs or yoghurt,' he said. 'Then date balls and dried mango during the run, electrolyte drink as soon as I've finished followed by a protein-based shake, and I've been drinking water every 10 minutes.'
He has also relied on ice to ease the pain. 'I've used ice buckets for my feet as soon as I've finished, followed by a warm shower and a massage.'
Izzard suffered a minor setback four days into the run streak, but not one to shirk his responsibilities, he has vowed to complete a double marathon on the final day.
22 days and 22 marathons into the challenge, the 54-year-old is on schedule to complete his final marathon in Pretoria on 20th March.
Follow Eddie's progress live on Twitter: @eddieizzard