War veteran and motivational speaker J.R. Martinez is out of his comfort zone -- again.

On behalf of Timex, J.R. Martinez will be running the New York City Marathon. And he'll be starting last. But every person he passes, Timex will donate $1 to the New York Road Runners Youth Program.

"Listen, I am not a runner at all. I didn't run this much in the military," said Martinez, who became nationally known for winning ABC's "Dancing With the Stars" last fall after a decorated military career. "I think it's cool to be outside my comfort zone because challenges allow you to see how far you can go."

Martinez has been an inspiration to millions, since sustaining severe burns to more than 40 percent of his body while serving for the U.S. Army in Iraq and recovering to become a motivational speaker.

While injured, Martinez also gained 70 pounds to 240 -- "on a 5-foot 9 frame. That's just not right," he said. "Then again, I was living in Texas and the eating is good there."

So he worked to get back into shape, getting his body right and his mind right.

"Knowing that I start dead last -- I mean dead last -- and realize we're giving money to the Road Runners group, I'm more than happy to do that," said Martinez, who will be using a Timex GPS watch to help his training. "I'm ready for the challenge."

Martinez did say he will accomplish one goal: Last year, softball star Jennie Finch, also working with Timex by starting last, raised a little under $31,000.

"I'm going out on a limb and say that my goal is $31,000!" Martinez said. "I might not be able to beat her time [4:05:26]. I'm not that confident. But I'll be able to finish the race. And I hope to inspire others."