VIENNA -- When Eliud Kipchoge's family finally gets to see him at a marathon, it will likely be the fastest one the Olympic champion has ever run.
The 34-year-old Kenyan's attempt to run a sub two-hour marathon has been set for Saturday in Prater park, a landmark part of the Vienna City Marathon.
Event organizers decided Wednesday to stick to the first planned race date, although they initially used a nine-day window to allow rescheduling for any unfavourable weather conditions.
But the optimum criteria for the INEOS 1:59 Challenge seem to be met on Saturday, with early morning temperatures expected between 5 and 9 degrees Celsius (41-48 Fahrenheit), humidity below 80%, dry conditions and not too much wind.
"We have looked at the weather patterns for Vienna coming through and the current conditions are looking to be optimal for temperature, humidity, wind and precipitation for this Saturday morning," said Robby Ketchell, who leads the weather analysis for the team.
Vienna's typical weather conditions this time of the year saw it preferred over London, where the chemicals company backing the attempt is headquartered.
The world-record holder's attempt to become the first person to complete the 42.2 kilometres (26.2 miles) in less than two hours will be witnessed by his family -- wife Grace and three children.
"It will be the first time they've ever watched me race, but I desperately want them to be in Vienna to see history being made," Kipchoge was quoted as saying on the event's website.
Kipchoge will start his run between 5 a.m. and 9 a.m., with the exact time only to be decided on Friday afternoon, based on the latest forecasts. His team will also take into account his body's circadian rhythm.
Kipchoge arrived in the Austrian capital from his Kenyan training camp in Kaptagat on Tuesday morning, saying he was looking forward to "showing the world that no human is limited."
This is Kipchoge's second attempt at breaking the two-hour barrier, after coming up 25 seconds short in a similar event, Breaking2, at Italy's Formula One track in Monza in May 2017.
Just like then, Saturday's finishing time will not be ratified by the IAAF as an official world record, because of variables such as pacemakers entering mid-race. That won't hurt Kipchoge too much as he owns the world record mark of 2:01:39 from the Berlin Marathon last year, when he knocked more than a minute off the previous record set by Dennis Kimetto.
To succeed at Saturday's challenge, Kipchoge will need to shave off more than 99 seconds, and nothing is being left to chance.
A team of 41 pacers includes: Olympic 1,500-meter champion Matthew Centrowitz from the United States; Ethiopia's Selemon Barega, who won silver in the 5,000 at the world championships in Doha and holds this year's world leading time in the 3,000; and Uganda's Ronald Musagala, who won two 1,500 races on the Diamond League circuit this year.
They will help keep Kipchoge at pace on the flat and 4.3-kilometre straight course, which is for most parts protected from the wind by high trees and has large roundabouts at both ends, enabling to make turns without slowing down. In August, organizers made the surface of the park's road smoother than ever by giving it a new coating.
To make the conditions completely perfect, though, Kipchoge also wants a bit of noisy crowd support.
"One element that is very important for Eliud is the crowd," the runner's coach Patrick Sang said, making an open plea for locals to come out "and cheer him on to help him make history.
