Founded in 2010, Tough Mudder now has six million participants worldwide, hosting 130 challenges and endurance events ...

Some unseasonably cool temperatures made for some cold water at some of the obstacles in Saturday’s Tough Mudder Indiana.

But Tough Mudder is also, as head course designer Nolan Kombol sees it, “a huge social experience. You’ll see people who’ll stay on top of Everest and help 15 or 20 people over.” ...

As part of the annual Dubai Fitness Challenge, Spartan Race and Tough Mudder will take over the Wadi Hub at Hatta Resorts on ...

Tough Mudder participants have climbed a total of about 5,700 vertical feet, plunged into 38 degree water, scaled the equivalent of an 11-story building in one obstacle, and jumped through fire.

The co-founder of Tough Mudder, the obstacle-course business with more than $100 million in sales, has had to tune out a lot of harsh critics--including himself.

Tough Mudder has hosted more than one million participants worldwide to date, and raised more than $6.5 million for the Wounded Warrior Project.

Tough Mudder is also adding new challenges for its "Legionnaires," or participants who have completed at least one event. Those obstacles include the Snot Rocket, a beefed-up version of the ...

Tough Mudder is a test of grit, not athletic prowess. (From the Mudder pledge recited just prior to the event: "I do not whine -- kids whine.") ...

U.S. Customs and Border Protection (CBP) is hosting a recruiting event at Tough Mudder Chicago on August 23rd and 24th, with ...

Tough Mudder's obstacles will for the first time include "Kong Infinity," a 15-foot climbing challenge invented by more than three million former Mudder athletes; and "Happy Ending," a 25-foot ...

Dean said Tough Mudder had signed up 70 franchisees in the U.S. and could do as many as 1,000 in the U.S. and another 1,000 abroad. Follow USA TODAY reporter Nathan Bomey on Twitter @ NathanBomey.