As the days grow shorter, cooler and rainier, a sizable group of people around the country start spending a lot more time outside.

They're marathoners, and this is the beginning of their season. Most races in the US fall between October 1st and April 30th -- Chicago, New York, Philadelphia, Boston -- and in those seven months, tens of thousands of Americans earn the medals that prove they endured the grueling 26.2-miles that comprise the modern-day marathon.

And most of those medals wind up in dresser drawers, framed behind glass, or in my case, hanging from a lamp in my living room.

In 2005, an Indiana doctor started a charity that breathes new life into those inert medals: as gifts to terminally ill patients struggling through marathons of their own -- for life against the odds.

Dr. Steven Isenberg began Medals4Mettle more-or-less by accident after completing the 2003 Chicago Marathon. When he returned home to Indianapolis, he paid a visit to a colleague who was hospitalized with prostate cancer and had tubes running in and out of his whole body. Speechless, Dr. Isenberg retrieved his finisher's medal from his pocket, placed it around his friend's neck, and said, "I want you to have this. You are running a much more difficult marathon than the one I completed."

Since 2005, the charity has collected an untold number of medals and donated them mostly children, but adults too have been grateful recipients of the inspiring symbols of strength and perseverance. Even Brian Sell, who was one of three American men to run the Olympic marathon this year, donated his medals at a children's hospital in Austin, Texas last February.

I personally began running in part because I felt a certain obligation to take advantage of the healthy body I was born with. It seemed a waste to take such a gift for granted and throw it away by smoking and eating bad food. I wanted to run because I knew that so many people couldn't.

Medals4Mettle provides a stellar opportunity for those of us fortunate enough to be capable of running for more than 26 miles at a time to share that accomplishment with someone whose own feat of endurance and strength awards no medal at all.

I nearly cried after I finished my first marathon when a volunteer placed the medal around my neck. For me, it symbolized a personal triumph over what had been the hardest year of my life. I can only imagine how such an honor would affect someone who can't even walk to the bathroom.

If you're running a marathon this year and want to donate your award, you may do so here.