Monza in May for Nike Breaking2

On May 6, exactly 63 years to the day after Roger Bannister became the first person to run a sub-4:00 mile, three runners might attempt to run the first sub-two-hour marathon. Or they might not.

That’s because Nike’s Breaking2 project, which features star runners Eliud Kipchoge, Zersenay Tadese, and Lelisa Desisa, is penciling in a three-day launch window to ensure they run in ideal weather conditions. The attempt will take place at the Formula One track in Monza, Italy, with May 6 as the first choice and May 7 and 8 as back-up dates.

The race will be streamed live around the world, with a broadcast hosted by veteran sports journalist Sal Masekela and additional commentary from NBC analyst and Nike executive Craig Masback and others. Details of how to access the stream haven’t yet been released.

The use of a flexible starting date is unconventional, but it’s one of the key advantages gained by staging a stand-alone time trial instead of going for the record in an existing big-city race. It’s the same approach, for example, that cyclist Eddie Merckx used in his famous one-hour record in 1972, which was set at an open-air velodrome in Mexico City.

If history is a guide, early May in Monza should offer relatively cool conditions with an average low of about 12ºC, along with low humidity, little wind, and cloud cover. Still, getting all those things to line up on the same day isn’t easy; the Breaking2 team’s half marathon dress rehearsal on March 7, for example, faced unexpectedly strong winds—though, as if to confirm the launch-window theory, conditions were once again perfect the next morning.

Nike’s weather modeling suggests that, within any three-day window in early May, they should have a roughly 90 percent chance of getting at least one perfect day, according to Brett Kirby, the project’s lead physiologist.

Leading up to the date, they’ll continue to monitor forecasts, and make a preliminary call on the race date a week before the launch window. The final decision won’t come until a few days before the race.

Whenever the race happens, Runner’s World will be in Monza to cover it.