Rock 'n' Roll Half Marathon and 5K returns to downtown Chicago

CHICAGO (WLS) -- More than 20,000 runners took part in the sixth annual Rock N' Roll Half Marathon and there were even more people on the sidelines cheering them on.

for the first time it was actually a race weekend with two days of running, a 5k event Saturday and Sunday, and of course, the 13.1 mile half-marathon.

For 25-year-old Andy Wacker, it started as just a working weekend in Chicago.

"I work for a small company, Roll Recovery, out of Boulder, Colorado, we came here to work the expo and I said, 'Let's just run it for fun,'" he said.

His "fun run" turned into Wacker being the first person to cross the half-marathon finish line.

"It was great," he said. "Every race is challenging, you never know how it's going to play out. There are a lot of great athletes here."

Like former San Francisco 49ers running back and three-time Super Bowl winner Roger Craig, who ran the half marathon and says he loves the health challenge.

"This is my coffee, this is my caffeine. When I come out here and run I don't need caffeine, I don't need coffee I just get out here and run," he said.

For many others, they run to raise awareness for their charities.

Like the "Ups For Downs Group," serving families that have Down syndrome, or know someone that does.

"We've got a team of 20 youth with Down syndrome that's out running and we are out here to let people know that people with Down syndrome belong in their communities where they live, learn and love play and pray and run," said runner Sandy Pazerunas.

And raise money for a great cause.