Organizers expect up to 18,000 people to participate in the event on Sunday.

Up to 18,000 runners from around the world are arriving in Houston for Sunday's marathon. The event, which includes a half-marathon, starts at 7 a.m. at Minute Maid Park.

"It's grueling, especially as I get older," says Wayne Rutledge, who is running the Houston Marathon for the 30th year. "When I ran my first marathon, it was a five mile loop inside Memorial Park. The water station was the back of a station wagon."

The course winds through Memorial Park and the Galleria, ending at the George R. Brown Convention Center.

"It's great to run here because of the people out there, people you'd never see another time," says Houston resident Steve Boone, who will complete his 400th marathon on Sunday. "The fans are great. They're out there rooting for you."

Boone founded a club for runners who have completed a marathon in all 50 states. He met his wife at the Boston Marathon 12 years ago.

"This is home, though," he adds. "We have a lot of people who will stay with us. Some are coming in from England to stay at our house. We get a chance to show off the city a little bit."

The first Houston Marathon took place in 1972.
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