There's only one 5k where no one races for a cure, because everyone's abandoned hope for an antidote: Run For Your Lives, a December 15th multi-path jaunt just hitting Cen-Tex for the first time, where racers flee brain-hungry zombies to benefit the Red Cross, which is good at fighting the sort of calamities that don't inspire AMC shows
The whole thing's taking place 40min SE in Cedar Creek, where they're setting up 12 obstacles along the lines of the Pits of Blood, traversed by running/jumping/crawling (Rule #1: Cardio). So that they might better snag flags from your "health belt", a crew of volunteers will be undeadified at the on-site Zombie Training Facility, which you could've sworn was in College Station
Should either Stumblers or Chasers snag all three of your flags you'll be marked as "Dead" on arrival at the Safety Zone, but if you're the quick and the dead you'll be enrolled in Chasing 101 and sent back to hunt down the remaining runners.
Survivors and walking dead alike will receive moisture wicking tees from Warwear, as well as medals of honor/dishonor. Afterwards you'll rage at an Apocalypse Party featuring bands, copious drinks, and celebrities (?), and there's also an overnight camping option where you can... not shower, and abandon all hope of getting brain.