Transcript for Steve Gleason Talks New Documentary
All right, back now with my exclusive interview with football hero Steve Gleason and a personal hero of mine, his wife Michel turning heartbreak into inspiration. Steve was diagnosed with als in 2011, just weeks before his wife learned she was pregnant. What they decided to do next will blow you away. September 2006, the New Orleans saints back in the superdome for the first time since hurricane Katrina ravaged their city. Early in the game, defensive back Steve Gleason blocks a punt for his team. Reigniting the fire within so many who lost so much. Look out. Breakthrough. Caught by Steve Gleason. Reporter: Gleason, a hero then and a hero now but for a different reason. I've been diagnosed with am Joe trophic lateral sclerosis which can a disease in the motor neurons and this disease is almost always fatal. Reporter: Within a few years, the once forceful football player loses his ability to move, to talk and eventually to breathe. Today he relies on a computer to speak and a ventilator to stay alive. One second you walk out onto the feel and you're seen as a hero. And then you can't control your simple body functions. So how do you deal with that dichotomy. Here's my thinking. My life ain't easy but it's awesome. I had some incredible moments on the football field. But I've had even more uplifting moments off the field. Since diagnosis. Reporter: Six weeks after the diagnosis, his wife Michel finds out she's pregnant. The young couple's new mission, to record hundreds of videos for their unborn son named rivers. While Steve still has the chance. Hey, how are you? How are you now. When we learned about rivers it made sense to me to share with rivers as much of myself as possible. Boo. Reporter: 1300 hours of video becoming a documentary called "Gleason." Why did you decide to share this -- these moments? I mean you're so open, but you're sharing this to the world in this movie? What made you decide to do it. We could have made a movie that glosses over the hard parts and just showed the hero part and the easy parts, we wanted to show the truth if we're going to do this we'll go all out and show the truth of our lives. How is it raising a son when you have als. I'm relentlessly pursuing ways to be a better dad. I pick up rivers every day from school. I'm at all of his practices. I get to help get him ready for bed at night. I love being rivers' daddy. Reporter: Throughout the film, there is some moments of incredible humor. How do you keep that going? You got to do something and we're both funny. We're both funny people, I think, so laughing has been one of the best solutions to get through this because otherwise like what else are you going to do? You know. You get funnier after diagnosis. Humor in the face of adversity is an excellent weapon. I like to say I'm a naturally funny dude but in reality I think I just have no choice. Humor is definitely healing. So I think we've tried to use it that way. I mean it was amazing to sit there with Steve and his wife Michel and, you know, one thing about all the people with als including Steve is although he's lost his ability to move, to talk and all those things his brain works perfectly. He's got a great sense of humor. He has a great sense of humor. He's smart as a whip. The first thing he did was give me a hard time when I walked in the room because I pronounced when I was commentating on fox he remembered something I did in 2011 where -- or 2 thou -- yeah, '11, I messed up the name of Scott Fujita and called him Scott fajita and he buffed me on it and teased me on it. We had to give him his questions in advance since it takes him longer to respond through his computer and as you see, inspirational and his wife Michel is amazing, as well. This documentary is a movie, "Gleason" and opens in select theaters Friday. You can see more of my interview with Steve and Michel Gleason on "Nightline" on Friday, as well. Unbelievable. Thank you for sharing. Coming up next, pentatonix.
This transcript has been automatically generated and may not be 100% accurate.