Transcript for An American veteran wins gold in the military's Wounded Warrior Games
Finally tonight, the comeback. The marine who nearly didn't make it back from the battlefield and the woman who changed his life by challenging him. For Mike Nicholson, summertime is a tough time of year. It's generally a little rougher because that was the time we were deployed in Afghanistan, and a lot of guys got hit. Reporter: Including Mike. I got hit by a 40-pound ied in Afghanistan. Took both legs and my left arm. Reporter: His new body, and the life that came with it brought a lot of anger and depression. Mike says he started drinking. But then he met his wife, and they married and started a family. She had a challenge for him, what if he tried exercising again. I mean, I'll give it a shot. Find out that you're going to be a lot happier in life. Reporter: That was the start of his comeback. This weekend he gave his all in the military's wounded warrior games, celebrating those hurt defending America. Mike has won gold and silver medals for track. And competes in wheelchair basketball. And maybe most amazing of all, swimming. I love swimming, and I found out once I got in the water I still could swim pretty well. Reporter: Also at the games, Mike celebrated his "Alive day," the day he was wounded. Now it's filled with competition and reflection. Feeling you are having a tough day, getting out here and getting a little sweat going and some physical exertion, I think it's the best medicine. So tonight, we salute Mike Nicholson's comeback, and thank him for his service. We thank you for watching. I'm Tom llamas in New York.
This transcript has been automatically generated and may not be 100% accurate.