Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: London (CNN) British astronaut Tim Peake provided the countdown for the 36th London Marathon Sunday before running his own virtual version of the race on a treadmill hundreds of miles above the Earth. A recorded message in which Peake wished the competitors luck was played on big screens before the runners set off in London and the 44-year-old astronaut began his own run on board the International Space Station. Kenyan long-distance runner Eliud Kipchoge won the men's race, in a course record time of two hours, three minutes and four seconds to triumph at the event for the second year in a row.UK astronaut Tim Peake runs 'virtual' London Marathon on a treadmill in orbitKenya's Eliud Kipchoge and Jemima Sumgong take titlesKipchoge just outside men's world recordThe millionth runner in the event's history will cross the finish line 
 Question:The video was populated with avatars depicting actual _ runners who are using the Run Social app as they race.

London