GEOFF BENNETT: Thousands of runners have been training for this Sunday's New York City marathon.

And one of them is representing a running club inside California's San Quentin Prison.

The group is featured in a new documentary playing on the state's prison TV network and for its parole board.

Special correspondent Mike Cerre has the story of the film "26.2 to Life" for our arts and culture series, Canvas.

MAN: Knowing you are going to be locked up for the rest of your life, you got to have ways to cope.

MIKE CERRE: The new documentary "26.2 to Life" chronicles San Quentin's 1,000 Mile running club training for its annual 26.2-mile marathon inside the prison's exercise yard.

MAN: It allows you to feel like you're doing something normal, that you're doing something that's not prison.

MIKE CERRE: First-time film director Christine Yoo wanted to break down the viewers and her own preconceptions of inmates serving indeterminate and in many cases life sentences.

CHRISTINE YOO, Director, "26.2 to Life": I really only knew about prison life from what we see in Hollywood movies and TV series and popular culture.

So when I first walked into San Quentin, my initial perception was really off.

Christine Yoo spent six years visiting, volunteering, and documenting this inspiring rehabilitation program started by veteran marathon runner and coach Frank Ruona.

FRANK RUONA, Founder, 1,000 Mile Club: We named the club the 1,000 Mile Club.

The idea was to have the inmates run 1,000 miles while they were at San Quentin.

Hey, we're going in 10, nine, eight.

MIKE CERRE: The culminating marathon held each November since 2008 is only one of the film's story arcs and more of a backdrop for the equally dramatic backstories of the runners.

Let's talk about the three characters that play the most prominent roles.

CHRISTINE YOO: Markelle was somebody that I met on the first day that I visited San Quentin, because he was the fastest man in the club.

He was the gazelle.

And I was immediately struck by his very gentle and soft-spoken manner.

MARKELLE TAYLOR, Inmate: They have a lot of programs here, and you got a lot of outside people here, but this is still prison.

It gets violent.

FRANK RUONA: Markelle looks awesome.

He's got a nice drive going.

CHRISTINE YOO: Even though this was a film about running, I wanted to look at the club and prison life from a more diverse perspective.

So, while Markelle was the fastest runner, Rahsaan was the slowest runner.

This guy has a 55-to-life sentence, but has an incredible sense of humor and a different way of looking at things.

RAHSAAN THOMAS, Inmate: I decided to put in something positive and, like, not let these people think they're right about me, not let my son grow up thinking that his dad is a loser.

MIKE CERRE: Tommy Wickerd is serving a 57-year sentence for murder and gang-related activities.

TOMMY WICKERD, Inmate: This doesn't happen in every prison.

You got to remember, all I did was hang around gang members and do drugs and sell drugs and hurt people.

Now I'm around coaches that are just like my mom and dad growing up with good people.

CHRISTINE YOO: I originally met his wife, Marion, and so I thought, wow, this is an -- would be an amazing opportunity to show what being a father or a husband from prison is really like.

MIKE CERRE: Despite the prison marathon's six 90-degree turns, Markelle "The Gazelle" Taylor wins the race in little over three hours.

Tommy Wickerd completed his 105 laps around and through the crowded prison yard under four hours.

MAN: No one said it was going to be easy.

You're doing great.

MIKE CERRE: And Rahsaan "New York" Thomas predictably finished last.

RAHSAAN THOMAS: I'm supposed to be miserable.

MAN: Making the final lap here.

RAHSAAN THOMAS: I'm supposed to be a failure.

I'm supposed to give up.

I'm supposed to die in here.

MIKE CERRE: The film doesn't overly play up the race for its primary drama or conclusion.

The rest of the story is even more inspiring.

MARKELLE TAYLOR: My goal is to run under three hours, maybe qualify for Boston here, be the first one to do that.

CHRISTINE YOO: I knew that he had been denied parole twice, but sort of shame on me for thinking that dreams don't and can't come true.

So, to have that goal and to maintain that dream from inside, I think, says a lot about his mental and spiritual fortitude.

MIKE CERRE: Markelle was paroled on his third attempt, after serving 17 years of his 15-to-life sentence for second-degree murder.

He has since run the Boston Marathon twice, once under three hours, and has been sharing his story and the film with juvenile offenders around the country.

MARKELLE TAYLOR: I'm an ambassador for lifers, life-incarcerated men and formerly incarcerated men, and what I experience and what I go through can help change policies in a way people are being treated, even from the outside or the inside.

MIKE CERRE: Markelle works full-time at a local supermarket while training for New York and other marathons, and spends evenings back inside San Quentin, now as one of the 1,000 Mile club's volunteer coaches.

California's Governor Newsom commuted Rahsaan "New York" Thomas' sentence after serving 23 years in prison.

TOMMY WICKERD: Here in San Quentin, we call this the bottleneck.

You have -- you go from dirt to asphalt, and if you step on a rock at 22 miles, it's going to get your attention.

Tommy Wickerd is the current president of San Quentin's 1,000 Mile Club.

His release date is 2045, unless he gets paroled sooner.

CHRISTINE YOO: I didn't want to make an issue film.

I would like for the audience to, after having seen it, for them to decide if they think that our approach to incarceration is -- can be improved or not.

MIKE CERRE: Perhaps its most captive and important audiences have been at the first San Quentin screenings.

The film is renewing the conversation about sentencing and rehabilitation, starting with the director of California's adult prisons, Ron Broomfield.

RON BROOMFIELD, Director, California Prisons: And I think your discipline and your honesty and your commitment is going to inspire people to really look at incarcerated in a different light.

CHRISTINE YOO: People who are at the highest levels of the Department of Corrections and in the state government can see the potential, that rehabilitation does work and hopefully that the film can be used as a tool to advocate for more of that.

MARKELLE TAYLOR: Not only is it helping you from a mental aspect and a physical.

It is also spiritual.

And it's all everything combined.

And it's more hands-on with people involved with helping you to reach your goals in life.

MIKE CERRE: For the "PBS NewsHour," Mike Cerre in San Quentin, California.