CHICAGO (CBS) — Thousands of Chicagoans started their Sunday with a high impact workout. They ran the five miles of the Shamrock Shuffle.

More than 25,000 runners took part in the 8K race Sunday morning.

Some put the fun in fun run, hoofing it in a tutu or green body paint. For competitive runners, the Shamrock Shuffle is the start of their racing season.

Peter Martin of Naperville is warming up for a busy summer.

“Getting in shape starts about now,” he said. “I do a lot of triathlons, so I’ll be doing Racine and the Chicago Triathlon later this year.”

Emily Trittschuh of Lake Zurich says she was energized by the cheering along the route.

“It’s definitely that little boost of motivation that you need, especially toward the end coming up the hill and then all the way down being lined by fans.

Trittschuh is getting ready for a much longer race, the Chicago Marathon in October.