Eliud Kipchoge insists he is "running to make history" when he bids to become the first marathon runner to break the two-hour barrier in Vienna on Saturday.
The Kenyan is taking his second official shot at the record - which would be unofficial - after missing out by 25 seconds in his first attempt in Monza two years ago.
Kipchoge will race alone in the IENOS 1:59 Challenge, but will he assisted by a rotating group of pace-setters, meaning his time cannot be officially ratified by the sport's governing body, the IAAF.
Kipchoge, a four-time London Marathon winner who also holds the official marathon world record of 2:01.39, said: "I am running to make history - I am running to tell people no human is limited.
"It's not about money, it's about running and making history and changing the lives of people through their thinking."
Kipchoge's challenge will take place over 4.4 laps of the Prater Hauptallee in Vienna.
He added: "I feel more prepared (after Monza). I feel confident that I have been at that speed for the past two years.
"I came close the first time, but I hope the second time I can get it."