If you're planning to do a table service breakfast after the race, make that reservation in advance. It's very hard to get into one of the park's restaurants right after a race since every other runner wants to eat as many Mickey waffles as possible, too. For a post-race breakfast or brunch, I like Grand Floridian Cafe at Disney's Grand Floridian Resort and Spa, Whispering Canyon at Disney's Wilderness Lodge, or California Grill at Disney's Contemporary Resort (Saturday and Sunday only).
Image Source: POPSUGAR Photography / Megan duBois