World Half Marathon Championships will take place simultaneously with citizens race.
In 2013, 1,100 U.S. marathons generated a record 541,000 finishers.
Marc Davis' mark of 13:24 has stood since 1996.
Lauren Kleppin and Tyler Pennel will compete in Saturday’s World Half Marathon Championships in Copenhagen.
The 21-year-old professional triathlete carries a lot of inspiration into Sunday's Carlsbad 5000.
More than 77,000 marathon hopefuls applied for spots in the 2014 race.
The race will be broadcast live Sunday at carlsbad5000.com/live.
Planning and organizing a race is a much bigger challenge than it first seems, writes Daniel Seidel.
The coverage will honor those affected by the tragic events of April 15, 2013.
What might be next for one of America's most popular distance runners.