On November 5th, thousands of runners will take over the streets of New York for the city's annual marathon. For many participants, this is an event they've spent years training for, but for Dean Karnazes, it will be just another day at the office. The ultra-distance runner is competing in 50 marathons in 50 days in 50 states, ending with the New York Marathon next month. He was nearing the half-way mark with the New Mexico Marathon in Albuquerque earlier this month.

Gloomy, misty weather on that Sunday morning grounded Albuquerque's annual hot-air balloon festival, but it didn't keep Dean Karnazes and a few dozen other runners from hitting the streets.

This was Karnazes' 22nd marathon in as many days, but at the end of the 42 kilometer course along the Rio Grande, he's all smiles as he announces to the cheering crowd at the finish line, "I feel great, absolutely terrific! It was a great group of people and a wonderful run right along the river, a lot of support along the way and people cheering, it was just terrific!"

He looks ready to run another marathon this afternoon, and the truth is, he probably could. Since throwing himself into the world of ultra-distance running back in 1993, Karnazes has made a name for himself in the sport with a bestselling book and a list of high-profile accomplishments. He once ran for three straight days and nights, forsaking sleep to complete a 563 kilometer trip around the San Francisco Bay Area.

For many of the other runners running in the New Mexico Marathon, like computer technician Andrew Maldonado, Karnazes is a true inspiration. "I did my second marathon and read his book after that and now this is my tenth [marathon] that I've finished. He's an incredible guy, amazing to be out there running endless miles and then order some food to keep running."

Jason Hill made the eight-hour drive from Denver to Albuquerque for today's marathon. This is his third time running with Karnazes in two weeks. "You know what," he says, "you get tired, but it's really a great group and everyone kind of hits highs at different moments and there's always someone who's really jazzed about the whole thing and Dean has got a smile on his face no matter what you do. It's really fantastic to have his spirit out there."

Dean Karnazes wants more than his spirit out there. He's running more than 2000 kilometers in less than two months to get his message out there. Karnazes says he was inspired by some of the troubling statistics surrounding fitness in America. "I'm trying to issue a wake up call to this country that we need to reclaim our health," he explains. "Obesity is at epidemic proportions right now. One-third of our youth, that's 25 million of our young people, are either overweight or obese. So what I'm trying to do is reach out to as many people as possible and say: 'exercise and fitness can be a fun and rewarding part of your life and if you don't have your health, you really don't have anything.'"

Dean Karnazes has been raising money for charity through his running for the past several years. This year, he founded his own charity, Karno Kids, which encourages young people to be physically active. Part of the $100 race fee that each runner paid to run with him today will go directly to Karno Kids, which in turn supports organizations like Girls on the Run. Christine Edwards, from the group's New Mexico chapter, explains that it's an after-school program for pre-teen girls. "Often they have no physical education at all. They don't walk, they don't play, so these are kids off the couch. We are so proud and so glad that Karno Kids is so supportive of Girls on the Run."

After each marathon, Karnazes spends a few hours visiting with runners and reporters and signing copies of his book. Then he climbs back onto a bus to head on to the next state and the next day's race. The constant travel and limited sleep have given him a cold, but his high-energy diet keeps him going.

While most runners follow up a marathon with a few days of relaxation, Dean Karnazes says that resting is his least favorite part of the entire experience. "The worst part is that I've gotta sleep," he says with a laugh. "I'm averaging four hours of sleep a night and I just don't want to sleep for 50 days. I'm having such a ball and meeting so many great people. So, if I could find a way not to sleep and still feel rejuvenated, I wouldn't!"

To follow Dean Karnazes on his marathon of marathons, check out his website.