CHICAGO (CBS) – Roller Derby is celebrating its 82nd birthday in Chicago with World Roller Derby Week.

Roller Derby athletes, in full uniform and skates, were in Coliseum Park on Wednesday passing out invitations to a free birthday party for the sport, which was invented in Chicago.

The sport of Roller Derby, which has been gaining in popularity, is celebrating its Chicago roots starting this Sunday with World Roller Derby Week.

“We are here promoting World Roller Derby Week, which starts this Sunday – Roller Derby’s 82nd birthday here at Coliseum Park,” it all started at 14th Place and Wabash Avenue, site of the old Chicago Coliseum in 1935, said Elizabeth Perez, aka Cuban Miss Elle.

“So we are going to have skaters represented from the Midwest Allstars and the local Illinois junior roller derby teams. We are also going to have the Moxi skate team here showcasing some amazing moves.”

Perez showed off some moves of her own on Wednesday with some other skaters in Coliseum Park, located at 14th Place and Wabash Avenue.

WBBM: How much contact is allowed now?

“Full contact,” Perez said. “Here’s the thing, I can’t hit you in the face. I can’t intentionally punch you or anything.”

So how tough do you have to be then?

“The sport itself may be tough; I would say it is more of a mental toughness, than a physical. We skate against men.”

She said there is a lot more athleticism in the sport today.

More details on World Roller Derby Week can be found on their Facebook page.