Last year's winner of Wellstone's White Rock Marathon broke the tape in 2 hours, 12 minutes and 4 seconds. At that pace, Moses Kororia could have run the 26.2-mile course twice more and finished with the runners who used every minute of the allotted time.

For the back-of-the-pack stragglers, the goal is more about participation than speed. They know they're not contenders for prize money or a threat to the would-be Boston Marathon qualifiers, but they enjoy exercising and being part of a big event.

"I'm not the typical runner. I'm pretty slow," said Sam Keohavong of Dallas, who finished in 6 hours and 21 minutes last year. "Some of my friends don't even believe I run because I don't have the typical runner's physique."

Officially, the slowest runners will have 6 1/2 hours to complete Sunday's event – a smidge under a 15-minute mile. By comparison, Mr. Kororia averaged 5 minutes, 2 seconds per mile.

Isaac Gian, who coaches a marathon training program at Luke's Locker in Dallas, said the abilities and goals of even the slowest runners in a marathon should be respected.

"It's harder because they are out there longer," Mr. Gian said. "Some of these runners will have some extra weight on them, but they are fit to do it because they have been training. They are out there, and they are just poking along – but God bless them, they are strong, and they know what they are doing."

Mr. Keohavong, 41, lost about 30 pounds during training and said he keeps running because he would like to drop a few more pounds and get faster.

He wants to shave an hour off his finish time Sunday. "I would like to do it in 5:30, but I want to be realistic, so I'll be happy if I do it in six hours," he said.

Last year, race officials had to mail Mr. Keohavong his finisher's medal because they had depleted their supply when he crossed the line. Also, choices for the finisher's T-shirts were thinned out, leaving Mr. Keohavong with one three sizes too big.

Mr. Gian considers it important for runners to collect the medal.

"The training is a six-month program, and these people come out every Saturday morning, and they work hard," Mr. Gian said. "Running a marathon is a very tough thing to begin with, and not everyone can do it. Those who come out really want to accomplish the feat. That medal is an important part of that achievement."

CINDY PRATER

Isaac Gian (center) coaches some of the slower runners in a marathon training program at Luke's Locker.

Some slow runners say they see potential to improve their speed.

Last year, Megan Duran, 29, of Dallas finished the marathon just before the cutoff with a time of 6 hours, 27 minutes, but she had strained muscles and nerves.

"I psyched myself out," Ms. Duran said. "I'm not a fast runner by any means, but I had had way better training runs than what my marathon time shows."

She said she persists because the training programs offer her a way to meet friends who are active.

"It's socially driven for me as well," she said. "I'm still good friends with the people I met during my first training program from two years ago."

Ms. Duran would like to cut an hour from last year's time. "I would love to run it in 5:30, which is probably not possible, but I keep telling myself I will only hurt for one day. I'm going to try to reach my goal."

Sherry Magnus, 51, didn't make the cutoff time last year with a finish of 6 hours, 59 minutes. "I hope I can really pull it out this year," she said.

While many runners go to the post-race party, the food and music are long gone by the time Ms. Magnus crosses the finish line.

"Afterward, I'm so wiped out," she said, "it doesn't bother me that there's no food left."