I am a son to a father who was homeless — living on the streets for 20 years and eventually dying there. My father's story can be told briefly, but the impact it has had on my life has been and will always be profound.

Brian O'Hearn, like myself, came from a household where the male role model was an abusive alcoholic. I've always believed a role model can teach you in one of two ways: Show you what to do or show you what not to do. Unfortunately, my father took his experience as a lesson in showing him what he was destined to become. I have chosen the opposite route.

It has taken me a long time to come to terms with my experience with my father, and to find the positives in such a dark situation. But the silver lining remains: It has made me determined to use it to create a positive impact on those around me. And I see a clear opportunity to help Philadelphians like my father — those who are experiencing homelessness, and may even struggle with addiction.

Philadelphia is the poorest large city in America, and more than 6,500 of our residents are living on the streets, in cars, and other places not meant for human habitation. Thousands more are in shelters. It's unacceptable that any of our city's men, women, and children lack a place to call home.

That's why on Dec. 22 I will set out to run 100 miles for Back on My Feet Philadelphia.

Although my father was not in a position to receive help, many people are ready to take steps toward a better life. That's where Back on My Feet comes in. The national nonprofit organization combats homelessness through the power of running, community support, and essential employment and housing resources.

Back on My Feet members, who are currently experiencing homelessness, wake up to run at 5:30 a.m. three days a week while simultaneously working on their recovery, securing a job, finding housing, and reuniting with their families. What starts out as a morning run has, in hundreds of cases, led to employment, keys to an apartment, and other milestones that many of us take for granted.

In the same vein, my continuous 100-mile undertaking is not just a run — my goal is to raise $25,000 to make Back on My Feet members' time in transition just a little bit easier. So far, I've raised more than $7,000, which is enough to provide three new members with gear, professional training workshops, and financial aid.

This will be the hardest thing I have ever attempted, but I know this is nothing compared with the challenges of those I am trying to support. So, I ask you this:

Will you join me?

You don't have to run 100 miles. Maybe it's just one mile, beside a Back on My Feet member, in support of his or her journey to independence. Or, instead of running, volunteer your time and resources to give hope to our city's most vulnerable.

However you choose to define it, your support will help bring us one step closer to ending homelessness in Philadelphia. It may even save the life of someone like my father.

Perry O'Hearn is the owner of Philly Phitness in Rittenhouse Square. Train@philly-phitness.com