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 planned race date, although they initially used a nine-day window to allow rescheduling for any unfavorable weather conditions.

The optimum criteria for the INEOS 1:59 Challenge seem to be met Saturday, with morning temperatures expected to be 41-48 degrees, dry conditions, and not too much wind.


‘‘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 this time of the year made it preferable to London, where the chemicals company backing the attempt is headquartered.

The world-record holder’s attempt to become the first person to complete 26.2 miles in less than two hours will be witnessed by his 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 and 9 a.m., with the exact time to be decided Friday afternoon based on the latest forecasts. His team also will take into account his body’s circadian rhythm.

Kipchoge arrived in the Austrian capital from his Kenyan training camp in Kaptagat 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 as 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 much, as he owns the world record of 2:01:39 at 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 of the US; Ethiopia’s Selemon Barega, who won silver in the 5,000 at the World Championships and holds this year’s world-best time in the 3,000; and Uganda’s Ronald Musagala, who won two 1,500-meter races on the Diamond League circuit this year.

The marathon will be run on a multi-lap, 9.6-kilometer course centered on Hauptallee, a long, straight, and tree-lined avenue. In August, organizers made the surface 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,’’ said his coach, Patrick Sang, making an open plea for locals to come out ‘‘and cheer him on to help him make history.’’