All 45,000 open slots for the October 10, 2010 Chicago Marathon have been filled, according to Cool Running. Race organizers closed registration this afternoon in record time. Registration was only open for 51 days this year. But those hoping to run the marathon aren't completely out of luck. The race holds spots open for charitable organizations and international tour operators.
Thinking about running, but scared to try? Check out our March 2010 article, "How to Train for a Marathon," and you'll be just fine.
-- Jonah Ogles