OK, so it’s one thing to go for a walk. To set out around the nearby streets of your neighborhood for a 30-minute stroll.

But how and why does one progress from that to deliberately walking 13.1 (because just 13 would be crazy, as racers like to joke!) or 26.2 miles?

For me, it’s about my grandmothers.

No matter where you stand on the nature vs. nurture continuum, we all have both in our makeup to some degree. When the opportunity first presented itself to walk a marathon (more on that in a future post), my thought process turned to my grandmothers.

At that time (2005), one of my grandmothers was not in the best of health. She was 81. During her life, she wasn’t really an exerciser, and her primary form of physical activity over the years was gardening and yard work. Sometimes she did a little stationary cycling.

My other grandmother tended to amaze everyone who met her. In 2005, she was 84, and she went hiking weekly with a hiking club she helped start when she was in her 60s. Even before that, in her 50s, she took up downhill and cross-country skiing, and in her 60s she bicycled across New Jersey (from the northwestern corner to the southeastern tip) with a cycling group on a week-long trip a few years in a row. She was active and fit — and quite healthy.

So, as I thought about whether I could/should/wanted to walk a full, 26.2-mile marathon, I thought of two possible outcomes for my old age, at least in terms of the “nature” angle. And it was clear to me that I wanted to age like my amazing, inspiring active Gram — and to accomplish that, I might want to step it up (no pun intended!) while I was still relatively young.

I registered for the race. And I’ll tell you in a future post how my active Gram joined me on the race course a few years later.