Nairobi, Feb. 13 -- Hours after Kelvin Kiptum confirmed his entry for this year's Rotterdam Marathon last November, organisers were forced to close registration for the April 14 race as the numbers immediately hit the ceiling.

Race Director Mario Kadiks was suddenly left dealing with a long waiting list of more than 14,000 runners, underscoring the rising profile of Kiptum, who is also the latest winner of the Business Daily's Top 40 Under 40 Men.

Kiptum, 24, had announced that he would attempt to run the April 14 Rotterdam Marathon in under two hours, seeking to become the first man to dip under two hours in a competitive marathon.

Read: Kipyegon, Kiptum win World Athletics awards

On October 12, 2019, Eliud Kipchoge clocked one hour,...