ST. LOUIS (KSDK) - If you're going to be anywhere near downtown Sunday morning you're going to need to be on the lookout for the more than 25,000 runners and road closures for the Go! St. Louis Marathon and Half Marathon.
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Both the half and full marathon runners will start downtown and head toward the Gateway Arch before turning to run by the Anheuser-Busch Brewery. They will then turn and run toward Forest Park.
Half marathon runners will turn back from there, but the full marathon will take participants to Clayton and University City before heading back downtown.
Runners will have 6.5 hours to complete the course, so the road restrictions will be in place until at least 2 p.m.
PDF: Marathon/half marathon race course
"The race actually starts at 7 o'clock, but we encourage people to start coming down early to get their spot, to feel comfortable, to check their bags, baggage check opens at 5:30 at City Hall so we want them to have a relaxing morning before they start the race," said Nancy Lieberman, president of Go! St. Louis.
Hundreds of those runners were at Chaifetz Arena Friday afternoon to pick up their race packets. It's also the site of the Health and Fitness Expo, which is open to everyone, not just those signed up for the race.
PDF: Race course description
The Health and Fitness Expo features a rock climbing wall and more than 40 vendors. The expo is open until 7 p.m. Friday, and from 10 a.m. until 7 p.m. Saturday.
"This is wonderful time to shop, see what's new in technology or new apparel or whatever so it's open to the public free of charge," said Lieberman.
If you really want to get in on the action, but haven't trained for a half of full marathon, it's not too late to participate in a couple of other fun runs Saturday.
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"Then we have the kids fun runs including the Diaper Dash and my favorite event which is the Mature Mile where people over the age of 60, with an average age of 78, with two women who are 100-years-old who will be at the start line for the Mature Mile. They will be walking that one mile," said Lieberman.
There's also a 5K run/walk Saturday morning at 8 a.m.
To sign up for any of these events visit the Go! St. Louis website.