Playing With Fire, Barbed Wire and Beer

A year ago, Tough Mudder was a semifinalist in the Harvard Business School’s annual Business Plan Contest. A British student named Will Dean thought he could attract 500 people to run a grueling race through mud and man-made obstacles. Professors generally considered the plan too optimistic.

“That was a big discussion,” said David Godes, a Harvard marketing professor last year who now teaches at the University of Maryland. “What was the target for this? Who’s going to do this?”

But on Sunday, the Brooklyn-based Tough Mudder will conduct a race for 4,500 people. Each has paid up to $100 for the privilege of negotiating a seven-mile obstacle course of muddy hills, cold water and flaming bales of straw at a ski resort near Allentown, Pa.

Tough Mudder has six employees and two interns, all in their 20s. It has plans for three more races around the country this year and about 10 in 2011, some projected to have as many as 20,000 participants. It announced itself with little more than $8,000 worth of Facebook advertising and a Web site (toughmudder.com), relying on the extrapolative power of social networking to generate an enthusiastic following. Tough Mudder has about 11,000 fans on Facebook and has attracted potential buyers.

Barring a calamitous first event, Tough Mudder appears to have found an opening in the burgeoning action-sports realm, tapping into the growing appetite for accessible-yet-demanding competitions.

The idea, imported largely from similar events in Britain (like the Grim Challenge) and Germany (the Strongman Run), is to stage events more convivial than marathons and triathlons, but more grueling than shorter runs or novelty events, some of which also have a mud-covered theme.