TODAY | May 30, 2013
>> 12 grueling miles, 25 down and dirty obstacles. and on this early morning outside chicago, 20,000 people who wouldn't want to be anywhere else. this is tough mudder, the vision of a former british counterterrorism officer who wanted to start a race where teammates helped teammates, teams help other teams and the race isn't a race at all.
>> it's a challenge. it's not about stepping over the next guy to the finish line , it's about turning around and helping them get over that finish line .
>> we're all here together. helping each other out.
>> and that spirit of comradery over competition has struck a cord worldwide.
>> we went from three events and 20,000 people in 2010 to 53 events and over 1 million people this year globally.
>> not bad considering some of the obstacles those people have to endure.
>> it's awesome. it's a dumpster full of 15,000 pounds of ice and basically the worst ice cream headache you're going to have.
>> savannah and natalie, i know you girls look nice on tv, but kiss the mud 40 feet on your bellies, like to see matt out here too.
>> each challenge tests not only the body but the mind, as well. facing a fear of heights, leaping over a blazing fire. or one obstacle that strikes fear into even the most seasoned tough mothers.
>> i've done 16 tough mudders. and it's 10,000 volts of live electric wires .
>> i get hit so hard every time. i got hit several times today. it's nasty.
>> why on earth would people put themselves through this?
>> something we'll remember as a group. that's what we're going to take away from it.
>> we work together and depend on each other and it's a good way to count on each other outside of work.
>> i'll tell you about the marine veteran out here on a prosthetic, the women running overcome cancer, and people running in memory of a friend who died in afghanistan. tough mudder brings it out.
>> come in a suit or tutu and in the end, everyone looks the same. many tough mudders have just one question.
>> when's the next one?