Thousands of people are expected to compete in Oshkosh this weekend in the Tough Mudders competition, an 11.8-mile run through mud and 18 military-style obstacles.
The competition is being held on the grounds of the Experimental Aircraft Association.
Oshkosh Northwestern Media reports it is designed to test strength, stamina and mental grit. Participants will wade through mud and try to avoid an electric shock as they near the finish line.
Nick Bodkins is a general manager for Tough Mudder events. He says they draw everyone from serious athletes to people who just want to have fun.
The two-day event runs Saturday and Sunday.